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Background: Paracoccidioidomycosis, a chronic granulomatous fungal disease caused by Paracoccidioides brasiliensis yeast cells affects mainly rural workers, albeit recently cases in immunosuppressed individuals has been reported. Protective immune response against P. brasiliensis is dependent on the activity of helper T cells especially IFN-γ-producing Th1 cells. It has been proposed that Paracoccidioides brasiliensis is able to modulate the immune response towards a permissive state and that the thymus plays a major role in it.Methods: In this paper, we show that acute infection of BALB/c mice with P. brasiliensis virulent isolate (Pb18) might cause alterations in the thymic environment as well as the prohibitive TCR-expressing T cells in the spleens.Results: After seven days of infection, we found yeast cells on the thymic stroma, the thymic epithelial cells (TEC) were altered regarding their spatial-orientation and inflammatory mediators gene expression was increased. Likewise, thymocytes (differentiating T cells) presented higher migratory ability in ex vivo experiments. Notwithstanding, P. brasiliensis-infected mice showed an increased frequency of prohibitive TCR-expressing T cells in the spleens, suggesting that the selection processes that occur in the thymus may be compromised during the acute infection.Conclusion: In this paper, for the first time, we show that acute infection with Paracoccidioides brasiliensis yeast cells promotes thymic alterations leading to a defective repertoire of peripheral T cells. The data presented here may represent new mechanisms by which P. brasiliensis subverts the immune response towards the chronic infection observed in humans. [ABSTRACT FROM AUTHOR]

Background: Antiretroviral therapy (ART) has transformed HIV management, with various regimens available. Dolutegravir (DTG) plus lamivudine (3TC) dual therapy is now the one of the first line regimens. Methods: A retrospective, observational study included treatment naïve people living with HIV (PLWH) with baseline HIV RNA viral load (VL) greater than 500,000 copies/mL from March 2020 to June 2022. PLWH on DTG + 3TC were included in the 2DR group, while others on INSTI-based three-drug regimens were divided in the 3DR group. Viral suppression, immunological recovery, and safety were assessed. Results: The study included 52 PLWH, with no significant baseline differences. Virologic suppression rates at weeks 24 and 48 were similar in both groups, even with baseline HIV RNA VL greater than 1,000,000 copies/mL. CD4 + T cell counts improved rapidly. No serious adverse effects were reported. Conclusions: DTG + 3TC dual therapy demonstrates effectiveness in treatment naïve PLWH with high baseline HIV RNA VL, suggesting its potential as a first line regimen for all treatment naïve PLWH. [ABSTRACT FROM AUTHOR]

Background: Among people living with HIV (PLHIV) on antiretroviral therapy (ART), the mortality of immunological non-responders (INRs) is higher than that of immunological responders (IRs). However, factors associated with immunological non-response following ART are not well documented. Methods: We obtained data for HIV patients from the National Free Antiretroviral Treatment Program database in China. Patients were grouped into IRs (CD4 cell count ≥ 350 cells/μl after 24 months' treatment), immunological incomplete responders (ICRs) (200–350 cells/μl) and INRs (< 200 cells/μl). Multivariable logistic regression was used to assess factors associated with immunological non-response. Results: A total of 3900 PLHIV were included, among whom 2309 (59.2%) were IRs, 1206 (30.9%) ICRs and 385 (9.9%) INRs. In multivariable analysis, immunological non-response was associated with being male (2.07, 1.39–3.09), older age [40–49 years (vs. 18–29 years): 2.05, 1.29–3.25; 50–59 years: 4.04, 2.33-7.00; ≥ 60 years: 5.51, 2.84–10.67], HBV co-infection (1.63, 1.14–2.34), HCV co-infection (2.01, 1.01–4.02), lower CD4 + T cell count [50–200 cells/μl (vs. 200–350 cells/μl): 40.20, 16.83–96.01; < 50 cells/μl: 215.67, 85.62-543.26] and lower CD4/CD8 ratio (2.93, 1.98–4.34) at baseline. Compared with patients treated with non-nucleoside reverse transcriptase inhibitors (NNRTIs) based regimens, those receiving protease inhibitors (PIs) based regimens were less likely to be INRs (0.47, 0.26–0.82). Conclusions: We found a sizable immunological non-response rate among HIV-infected patients. Being male, older age, coinfection with HBV and HCV, lower CD4 + T cell count and lower CD4/CD8 ratio are risk factors of immunological non-response, whereas PIs-based regimens is a protective factor. [ABSTRACT FROM AUTHOR]

Cross-reactive cellular and humoral immunity can substantially contribute to antiviral defense against SARS-CoV-2 variants of concern (VOC). While the adult SARS-CoV-2 cellular and humoral immunity and its cross-recognition potential against VOC is broadly analyzed, similar data regarding the pediatric population are missing. In this study, we perform an analysis of the humoral and cellular SARS-CoV-2 response immune of 32 convalescent COVID-19 children (children), 27 convalescent vaccinated adults(C + V+) and 7 unvaccinated convalescent adults (C + V-). Similarly to adults, a significant reduction of cross-reactive neutralizing capacity against delta and omicron VOC was observed 6 months after SARS-CoV-2 infection. While SAR-CoV-2 neutralizing capacity was comparable among children and C + V- against all VOC, children demonstrated as expected an inferior humoral response when compared to C + V+. Nevertheless, children generated SARS-CoV-2 reactive T cells with broad cross-recognition potential. When compared to V + C+, children presented even comparable frequencies of WT-reactive CD4 + and CD8 + T cells with high avidity and functionality. Taking into consideration the limitations of study - unknown disease onset for 53% of the asymptomatic pediatric subjects, serological detection of SARS-CoV-2 infection-, our results suggest that following SARS-CoV-2 infection children generate a humoral SARS-CoV-2 response with neutralizing potential comparable to unvaccinated COVID-19 convalescent adults as well a sustained SARS-CoV-2 cellular response cross-reactive to VOC. Key statement: Following SARS-CoV-2 infection children generate a humoral SARS-CoV-2 response with neutralizing potential comparable to unvaccinated COVID-19 convalescent adults as well a sustained robust SARS-CoV-2 cellular response cross-reactive to VOC, comparable to vaccinated convalescent adults with respect to magnitude and functionality. [ABSTRACT FROM AUTHOR]

Background: Increased frequency of circulating double negative T (DNT, CD4-CD8-CD3+) cells with protective immune function has been observed in human immunodeficiency virus (HIV) infection and tuberculosis (TB). Here the role of circulating TCRαβ+ DNT cells was further investigated in HIV/TB co-infection.Methods: A cross-sectional study was conducted to investigate the frequency and functional profiles of peripheral TCRαβ+ DNT cells including apoptosis, chemokine and cytokine expression among healthy individuals and patients with TB, HIV infection and HIV/TB co-infection by cell surface staining and intracellular cytokine staining combined with flow cytometry.Results: Significantly increased frequency of TCRαβ+ DNT cells was observed in HIV/TB co-infection than that in TB (p < 0.001), HIV infection (p = 0.039) and healthy controls (p < 0.001). Compared with TB, HIV/TB co-infection had higher frequency of Fas expression (p = 0.007) and lower frequency of Annexin V expression on TCRαβ+ DNT cells (p = 0.049), and the frequency of Annexin V expression on Fas+TCRαβ+ DNT cells had no significant difference. TCRαβ+ DNT cells expressed less CCR5 in HIV/TB co-infection than that in TB (p = 0.014), and more CXCR4 in HIV/TB co-infection than that in HIV infection (p = 0.043). Compared with healthy controls, TB and HIV/TB co-infection had higher frequency of TCRαβ+ DNT cells secreting Granzyme A (p = 0.046; p = 0.005). In TB and HIV/TB co-infection, TCRαβ+ DNT cells secreted more granzyme A (p = 0.002; p = 0.002) and perforin (p < 0.001; p = 0.017) than CD4+ T cells but similar to CD8+ T cells.Conclusions: Reduced apoptosis may take part in the mechanism of increased frequency of peripheral TCRαβ+ DNT cells in HIV/TB co-infection. TCRαβ+ DNT cells may play a cytotoxic T cells-like function in HIV/TB co-infection. [ABSTRACT FROM AUTHOR]

Background: To study whether the association between the CD4/CD8 ratio variation over time and the development of clinical outcomes vary in late presenters (CD4 count < 350/µL or AIDS event at enrolment) or advanced presenters (CD4 count < 200/µL or AIDS event at enrolment).Methods: We included ART-naïve adults from the Cohort of the Spanish HIV/AIDS Research Network (CoRIS) enrolled between January 2004 up to November 2018 and with at least 6 months of follow-up. We used extended Cox proportional hazard models to estimate the hazard ratios (HRs) for the association between CD4/CD8 ratio over time and a composite endpoint of the occurrence of the first AIDS event, first serious non-AIDS event or overall mortality occurring from 6 months after enrolment. HRs in non-late, late and advanced presenters were obtained by including an interaction term between late presentation status and CD4/CD8 ratio over time.Results: Of 10,018 participants, 55.6% were late presenters and 26.5% were advanced presenters. Compared with CD4/CD8 ratio > 0.4, CD4/CD8 ratio ≤ 0.4 over time was associated with an increased risk of experiencing the composite endpoint in non-late (HR 1.90; 95%CI 1.48, 2.43), late (HR 1.94; 1.46, 2.57) and advanced presenters (HR 1.72; 1.26, 2.34). Similarly, CD4/CD8 ratio ≤ 0.4 over time was associated with a higher risk of developing an AIDS event (HR 3.31; 2.23, 4.93 in non-late; HR 2.75; 1.78, 4.27 in late and HR 2.25; 1.34, 3.76 in advanced presenters) or serious non-AIDS event (HR 1.39; 0.96, 2.02 in non-late, HR 1.62; 1.10, 2.40 in late and HR 1.49; 0.97, 2.29 in advanced presenters) as well as with a higher risk of overall mortality (HR 1.49; 0.92, 2.41 in non-late, HR 1.80; 1.04, 3.11 in late and HR 1.61; 0.92, 2.83 in advanced presenters) compared to CD4/CD8 > 0.4, regardless of the late presentation status.Conclusions: A low CD4/CD8 measured over time is associated with increased risk of morbidity and mortality in people living with HIV independently of their late presentation status. These data support the prognostic role of CD4/CD8 over time and can help defining a subgroup of patients who need closer monitoring to avoid comorbidities. [ABSTRACT FROM AUTHOR]

Background: Complete clearance of intracellular viruses depends on effector cells of innate and adaptive immune systems. This study aimed to identify the relationships among antiviral cytokines produced by natural killer (NK) and T cells and clinical-virological characteristics in untreated chronic hepatitis B (CHB) patients.Methods: We measured antiviral cytokines interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and interleukin-2 (IL-2) produced by T, NK and natural killer T (NKT) cells, respectively, in a cohort with chronic hepatitis B virus (HBV) infection (CHB). We also correlated these cytokines with clinical-virological characteristics using a linear regression model.Results: levels of IFN-γ+ and TNF-α+ CD4+ and CD8+ T cells were significantly higher in immune active (IA) phase than in other phases. Immune tolerant (IT) patients showed the lowest expression of IFN-γ by NK and NKT cells, and TNF-α by NK cells. IFN-γ+, TNF-α+ and IL-2+ CD4+ and CD8+ T cells frequencies were similar between IA and gray zone (GZ) phases. Principal component analysis based on cytokines confirmed that most IT patients significantly differed from inactive carriers (IC) and IA patients, while GZ patients were widely scattered. Multivariate analysis showed both T and NK cells producing IFN-γ and TNF-α, but not IL-2, had significant association with serum alanine aminotransferase (ALT). Moreover, IFN-γ+ NKT cells were associated with HBV DNA, while IFN-γ+ CD4+ and CD8+ T cells were correlated with age.Conclusion: HBV clinical phases are characterized by distinct cytokine signatures, which showed relationship to viral features in these untreated CHB patients. [ABSTRACT FROM AUTHOR]

Background: Current WHO guidelines (2018) recommend screening for cryptococcal antigen (CrAg) in HIV-infected persons with CD4+ T cell counts< 100 cells/μL, followed by pre-emptive antifungal therapy among CrAg positive (CrAg+) persons, to prevent cryptococcal meningitis related deaths. This strategy may also be considered for those persons with a CD4+ T cell count of < 200 cells/uL according the WHO guidelines. However, there is sparse evidence in the literature supporting CrAg screening and pre-emptive antifungal therapy in those HIV-infected persons with this CD4+ T cell counts< 200 cells/μL.Method: We conducted a meta-analysis using data extracted from randomized controlled studies (RCTs) and cohort studies found in a search of Pubmed, Web of Science, the Cochrane Library and the EMBASE/MEDLINE database.Results: The pooled prevalence of CrAg positivity in HIV-infected persons with CD4+ T cell counts< 200 cells/μL was 5% (95%CI: 2-7). The incidence of CM in CrAg+ persons was 3% (95%CI: 1-6). Among those CrAg+ persons who did not receive pre-emptive treatment, or those who received placebo, the incidence of CM was 5% (95%CI: 2-9), whereas the incidence of CM among those who received pre-emptive antifungal therapy was 3% (95%CI: 1-6), which is a statistically significant reduction in incidence of 40% (RR: 7.64, 95%CI: 2.96-19.73, p < 0.00001). As for persons with CD4+ T cell counts between 101 ~ 200 cells/μL, the risk ratio for the incidence of CM among those receiving placebo or no intervention was 1.15, compared to those receiving antifungal treatment (95%CI: 0.16-8.13).Conclusions: In our meta-analysis the incidence of CM was significantly reduced by pre-emptive antifungal therapy in CrAg+ HIV-infected persons with CD4 <  200 cells/μL. However, more specific observational data in persons with CD4+ T cell counts between 101 ~ 200 cells/μL are required in order to emphasize specific benefit of CrAg screening and pre-emptive antifungal treating in CrAg+ persons with CD4+ T cell counts < 200 cells/μL. [ABSTRACT FROM AUTHOR]

Background: Tuberculosis (TB) and HV have been intertwined and makeup a deadly human syndemic worldwide, especially in developing countries like Ethiopia. Previous studies have reported different TB incidences and its association with CD4+ T cell counts among HIV positive patients in Ethiopia. Thus, the goal of this meta-analysis was, first, to determine pooled incident TB among adult HIV positive patients, and second, to assess the association between incident TB and baseline CD4+ T cell count strata's.Methods: We searched PubMed, Cochrane library, Science Direct and Google scholar databases from June 1 to 30, 2018. The I2 statistics and Egger's regression test was used to determine heterogeneity and publication bias among included studies respectively. A random effects model was used to estimate pooled incident TB and odds ratio with the respective 95% confidence intervals using Stata version 11.0 statistical software.Results: A total of 403 research articles were identified, and 10 studies were included in the meta-analysis. The pooled incident TB among adult HIV infected patients in Ethiopia was 16.58% (95% CI; 13.25-19.91%). Specifically, TB incidence in Pre-ART and ART was 17.16% (95% CI; 7.95-26.37%) and 16.24% (95% CI; 12.63-19.84%) respectively. Moreover, incident TB among ART receiving patients with baseline CD4+ T cell count < and > 200 cells/mm3 was 28.86% (95% CI; 18.73-38.98%) and 13.7% (95% CI; 1.41-25.98%) correspondingly. The odds of getting incident TB was 2.88 (95% CI; 1.55-5.35%) for patients with baseline CD4+ T cell count < 200 cells/mm3 compared to patients with baseline CD4+ T cell count > 200 cells/mm3.Conclusion: High incident TB among adult HIV positive patients was estimated, especially in patients with CD4+ T cell count < 200 cells/mm3. Therefore, Early HIV screening and ART initiation, as well as strict compliance with ART and increasing the coverage of TB preventive therapy to more risky groups are important to prevent the problem.Trial Registration: Study protocol registration: CRD42018090802. [ABSTRACT FROM AUTHOR]

Background: Emerging data has suggested that Tregs, Th17, Th1 and Th2 are correlated with early immune mechanisms by controlling Plasmodium infection. Plasmodium infection appeared to impair the antigen presentation and maturation of DCs, leading to attenuation of specific cellular immune response ultimately. Hence, in this study, we aim to evaluate the relevance between DCs and Tregs/Th17 populations in the process and outcomes of infection with Plasmodium yoelii 17XL (P.y17XL).Methods: DCs detection/analysis dynamically was performed by Tregs depletion or Th17 neutralization in P.y17XL infected BALB/c mice via flow cytometry. Then the levels of cytokines production were detected using enzyme-linked mmunosorbent assay (ELISA).Results: Our results indicated that Tregs depletion or Th17 neutralization in BALB/c mice infected with P.y17XL significantly up-regulated the percentages of mDC and pDC, increased the expressions of major histocompatibility complex (MHC) class II, CD80, CD86 on DCs and the levels of IL-10/IL-12 secreted by DCs, indicating that abnormal amplification of Tregs or Th17 may damage the maturation and function of DCs during the early stage of malaria infection. Interestingly, we also found that the abnormal amplification of Th17, as well as Tregs, could inhibit the maturation of DCs.Conclusions: Tregs skewing or Th17 amplification during the early stage of malaria infection may inhibit the maturation and function of DCs by modifying the subsets of DCs, expressions of surface molecules on DCs and secretion mode of cytokines. [ABSTRACT FROM AUTHOR]

Background: The impact of HIV-1 subtype (CRF01_AE and non-CRF01_AE) on HIV-1 DNA levels in HIV-1 chronically infected patients with suppressive antiretroviral therapy (ART) remains poorly understood. To evaluate the correlation of HIV-1 subtype with DNA level, and identify baseline predictors of HIV-1 DNA decay.Methods: ART-naïve HIV-1-infected patients from two large multi-center studies in China were classified into CRF01_AE and non-CRF01_AE subtype groups. Peripheral blood samples were collected at baseline and week 12, 24, 48 and 96 after ART initiation and total HIV-1 DNA levels were quantified by real-time PCR. HIV-1 DNA levels at week 96 were categorized into high, moderate, and low levels, reflecting HIV-1 DNA ≥ 3, 2-3, ≤ 2 log10 copies/106 PBMCs, respectively, and the corresponding proportion of CRF01_AE and non-CRF01_AE subtype were compared. The baseline predictors of low HIV-1 total DNA levels (≤ 2 log10 copies/106 PBMCs) at week 96 were evaluated using a logistic regression model.Results: Compared to the non-CRF01_AE subtypes (n = 185), patients with CRF01_AE subtype (n = 188) harboured a higher level of HIV-1 DNA (median: 3.19 vs. 2.95 log10 copies/106 PBMCs, P < 0.001) prior to treatment. After 96 weeks of ART, HIV-1 DNA levels remained higher in the CRF01_AE subtype group (median: 2.63 vs. 2.39 log10 copies/106 PBMCs, P = 0.002). There was no significant difference in the proportion of patients achieving high (22.3% vs. 14.6%, P = 0.054), moderate (59.6% vs. 60.5%, P = 0.849) and low levels (18.1% vs 24.9%, P = 0.111) between CRF01_AE and non-CRF01_AE groups. In the multivariable analysis, baseline HIV-1 DNA level and CD4+ T cell count but not the subtype were independent risk factors for achieving HIV-1 DNA level ≤ 2 log10 copies/106 PBMCs.Conclusion: HIV-1 CRF01_AE subtype is neither correlated with HIV-1 DNA reservoir decline nor a prognostic factor for achieving lower HIV-1 DNA levels (≤ 2 log10 copies/106 PBMCs) after ART. However, higher HIV-1 DNA level in HIV-1 CRF01_AE patients should be aroused much attention and strengthen surveillance during ART. [ABSTRACT FROM AUTHOR]

Background: Levels of non-neutralising antibodies (AB) to the C5 domain of HIV Env gp120 are inversely related to progression of HIV infection. In this phase I/II clinical study we investigated safety of Vacc-C5, a peptide-based therapeutic vaccine candidate corresponding to C5/gp41732-744 as well as the effects on pre-existing AB levels to C5/gp41732-744, immune activation and T cell responses including exploratory assessments of Vacc-C5-induced T cell regulation. Our hypothesis was that exposure of the C5 peptide motif may have detrimental effects due to several of its HLA-like features and that enhancement of non-neutralising anti-C5 AB by vaccination could reduce C5 exposure and thereby chronic immune activation.Methods: Thirty-six HIV patients on effective antiretroviral therapy were randomised to one of three dose levels of Vacc-C5 administered intramuscularly with Alhydrogel or intradermally with GM-CSF as adjuvant through initial immunisation and two booster periods over 26 weeks. Vacc-C5-specific AB were measured by ELISA and T cell responses by both IFN-γ ELISPOT and proliferative assays analysed by flow cytometry. Immune regulation was assessed by functional blockade of the two inhibitory cytokines IL-10 and TGF-β in parallel cultures. Non-parametric statistical tests were applied.Results: Vacc-C5 was found safe and well tolerated in all patients. Only marginal changes in humoral and cellular responses were induced, without any effect on immune activation. Overall, anti-Vacc-C5 AB levels seemed to decrease compared to pre-existing levels. Whereas Vacc-C5-specific CD8+ T cell proliferative responses increased after the first booster period (p = 0.020; CD4+, p = 0.057), they were reduced after the second. In contrast, Vacc-C5-induced T cell regulation increased after completed vaccination (p ≤ 0.027) and was lower at baseline in the few AB responders identified (p = 0.027).Conclusions: The therapeutic HIV vaccine candidate Vacc-C5 safely induced only marginal immune responses, whereas Vacc-C5-induced T cell regulation markedly increased. Our data support further attention on immune regulation during therapeutic HIV vaccination studies.Trial Registration: NCT01627678 . [ABSTRACT FROM AUTHOR]

Background: Human adenovirus 7 (HAdV-7) was responsible for a significant number of fatalities during the 2011 community outbreak in Taiwan. The mechanisms underlying the pathogenesis of severe adenovirus infections in non-immunocompromised individuals remain unclear. Adenovirus pneumonia was associated with pleural effusion in a number of patients from the 2011 outbreak suggesting that similar to bacterial pneumonia, patients diagnosed with adenovirus pneumonia who have pleural effusion are more severely and systemically infected, and may have a more protracted disease course. We hypothesized that the host immunological response determines the severity of adenoviral infection.Methods: This retrospective case series study included patients diagnosed with severe lower respiratory tract infections at the National Cheng Kung University Hospital in southern Taiwan between December 2010 and October 2011. The main inclusion criteria were 1) presence of multifocal patchy infiltrates, lobar consolidation or reticular interstitial opacities in chest X-rays, and 2) presence of adenovirus isolated from respiratory specimens. All patients had adenovirus isolated from respiratory specimens, and were negative for other viruses. Pleural effusion was confirmed in all patients using chest echography. Clinical features and laboratory data were compared in patients with (n = 12) and without (n = 15) parapneumonic effusion.Results: Presence of parapneumonic effusion was significantly associated with a longer febrile duration, more complicated clinical management, and a greater risk of extrapulmonary involvement, notably hepatitis. Patients without pleural effusion had significantly higher numbers of WBCs, platelets, and absolute segment cell counts (ASCs) compared to patients with pleural effusion (all p < 0.05). Patients without pleural effusion had significantly higher counts of CD4+, CD8+, and CD20+ T cells (all p < 0.05) compared to patients with pleural effusion.Conclusion: Our data indicated that presence of parapneumonic effusion in adenoviral pneumonia was associated with longer febrile duration, more complicated clinical management, a greater risk of hepatitis, and suppression of host cellular immunity. Further prospective, large-scale studies are needed to validate our results. [ABSTRACT FROM AUTHOR]

Background: In the last 20 years routine T CD4+ lymphocyte (CD4+) cell count has proved to be a key factor to determine the stage of HIV infection and start or discontinue of prophylaxis for opportunistic infections. However, several studies recently showed that in stable patients on cART a quarterly CD4+ cell count monitoring results in limited (or null) clinical relevance. The research is intended to investigate whether performing quarterly CD4+ cell counts in stable HIV-1 patients is still recommendable and to provide a forecast of the cost saving that could be achieved by reducing CD4+ monitoring in such a category of patients.Methods: The study is based on data referring to all HIV-infected patients > 18 years of age being treated at two large infectious diseases units located in the metropolitan area of Genoa, Italy. The probability of CD4+ cell counts dropping below a threshold value set at 350 cells/mm3 is assessed using confidence intervals and Kaplan-Meier survival estimates, whereas multivariate Cox analysis and logistic regression are implemented in order to identify factors associated with CD4+ cell count falls below 350 cells/mm3.Results: Statistical analysis reveals that among stable patients the probability of maintaining CD4+ >350 cell/mm3 is more than 98%. Econometric models indicate that HCV co-infection and HIV-RNA values >50 copies/mL in previous examinations are associated with CD4+ falls below 350 cells/mm3. Moreover, results suggest that the cost saving that could be obtained by reducing CD4+ examinations ranges from 33 to 67%.Conclusions: Empirical findings shows that patients defined as stable at enrollment are highly unlikely to experience a CD4+ value <350 cell/mm3 in the space/arc of a year. The research supports a recommendation for annual CD4+ monitoring in stable HIV-1 patients. [ABSTRACT FROM AUTHOR]

Background: Chronic Chagas disease presents different clinical manifestations ranging from asymptomatic (namely indeterminate) to severe cardiac and/or digestive. Previous results have shown that the immune response plays an important role, although no all mechanisms are understood. Immunoregulatory mechanisms such as apoptosis are important for the control of Chagas disease, possibly affecting the morbidity in chronic clinical forms. Apoptosis has been suggested to be an important mechanism of cellular response during T. cruzi infection. We aimed to further understand the putative role of apoptosis in Chagas disease and its relation to the clinical forms of the disease.Methods: Apoptosis of lymphocytes, under antigenic stimuli (soluble T. cruzi antigens - TcAg) where compared to that of non-stimulated cells. Apoptosis was evaluated using the expression of annexin and caspase 3(+) by T cells and the percentage of cells positive evaluated by flow cytometry. In addition activation and T cell markers were used for the identification of TCD4(+) and TCD8(+) subpopulations. The presence of intracellular and plasma cytokines were also evaluated. Analysis of the activation status of the peripheral blood cells showed that patients with Chagas disease presented higher levels of activation determined by the expression of activation markers, after TcAg stimulation. PCR array were used to evaluate the contribution of this mechanism in specific cell populations from patients with different clinical forms of human Chagas disease.Results: Our results showed a reduced proliferative response associated a high expression of T CD4(+)CD62L(-) cells in CARD patients when compared with IND group and NI individuals. We also observed that both groups of patients presented a significant increase of CD4(+) and CD8(+) T cell subsets in undergoing apoptosis after in vitro stimulation with T. cruzi antigens. In CARD patients, both CD4(+) and CD8(+) T cells expressing TNF-α were highly susceptible to undergo apoptosis after in vitro stimulation. Interestingly, the in vitro TcAg stimulation increased considerably the expression of cell death TNF/TNFR superfamily and Caspase family receptors genes in CARD patients.Conclusions: Taken together, our results suggest that apoptosis may be an important mechanism for the control of morbidity in T. cruzi infection by modulating the expression of apoptosis genes, the cytokine environment and/or killing of effector cells. [ABSTRACT FROM AUTHOR]

Background: In sub-Saharan Africa (SSA), antiretroviral therapy (ART) can prolong life for HIV-infected patients. However, patients initiating ART, especially in routine treatment programs, commonly dropout from care either due to death or loss to follow-up.Methods: In a cohort of HIV-infected patients initiating ART at a public sector clinic in Uganda, we assessed predictors of dropout from care (a composite outcome combining death and loss to follow-up). From a large set of socio-demographic, clinical, and laboratory variables routinely collected at ART initiation, we selected those predicting dropout at P <0.1 in unadjusted analyses for inclusion into a multivariable proportional hazards regression model. We then used a stepwise backward selection procedure to identify variables which independently predicted dropout at P <0.05.Results: Data from 5,057 patients were analyzed. The median age was 33 years (IQR 28 to 40) and 27.4% had CD4+ T-cell counts <100 cells/μL at ART initiation. The median duration of follow-up was 24 months (IQR = 14 to 42, maximum follow-up = 64 months). Overall dropout was 26.9% (established cumulative mortality = 2.3%, loss to follow-up = 24.6%), 5.6% were transferred to other service providers, and 67.5% were retained in care. A diagnosis of Kaposi's sarcoma (hazard ratio (HR) = 3.3, 95% CI 2.5 to 4.5); HIV-associated dementia (HR = 2.6, 95% CI 1.5 to 4.6); history of cryptococcosis (HR = 2.2, 95% CI 1.4 to 3.3); and reduced hemoglobin concentration (<11 g/dl versus ≥13.8 g/dl (HR = 1.9, 95% CI 1.6 to 2.2) were strong predictors of dropout. Other independent predictors of dropout were: year of ART initiation; weight loss ≥10%; reduced total lymphocyte count; chronic diarrhea; male sex; young age (≤28 years); and marital status.Conclusions: Among HIV-infected patients initiating ART at a public sector clinic in SSA, biological factors that usually predict death were especially predictive of dropout. As most of the dropouts were lost to follow-up, this observation suggests that many losses to follow-up may have died. Future studies are needed to identify appropriate interventions that may improve both individual-level patient outcomes and outcome ascertainment among HIV-infected ART initiators in this setting. [ABSTRACT FROM AUTHOR]

Background For a long time, the role of CD8+ T cells in blood-stage malaria was not considered important because erythrocytes do not express major histocompatibility complex (MHC) class I proteins. While recent evidences suggest that CD8+ T cells may play an important role during the erythrocytic phase of infection by eliminating parasites, CD8+ T cells might also contribute to modulate the host response through production of regulatory cytokines. Thus, the role of CD8+ T cells during blood-stage malaria is unclear. Here, we report the phenotypic profiling of CD8+ T cells subsets from patients with uncomplicated symptomatic P. vivax malaria. Methods Blood samples were collected from 20 Plasmodium vivax-infected individuals and 12 healthy individuals. Immunophenotyping was conducted by flow cytometry. Plasma levels of IFN-γ, TNF-α and IL-10 were determined by ELISA/CBA. Unpaired t-test or Mann-Whitney test was used depending on the data distribution. Results P. vivax-infected subjects had lower percentages and absolute numbers of CD8+CD45RA+ and CD8+CD45RO+ T cells when compared to uninfected individuals (p ⩽ 0.0002). A significantly lower absolute number of circulating CD8+CD45+CCR7+ cells (p = 0.002) was observed in P. vivax-infected individuals indicating that infection reduces the number of central memory T cells. Cytokine expression was significantly reduced in the naïve T cells from infected individuals compared with negative controls, as shown by lower numbers of IFN-γ+ (p = 0.001), TNF-α+ (p < 0.0001) and IL-10+ (p < 0.0001) CD8+ T cells. Despite the reduction in the number of CD8+ memory T cells producing IFN-γ (p < 0.0001), P. vivaxinfected individuals demonstrated a significant increase in memory CD8+TNF-α+ (p = 0.016) and CD8+IL-10+ (p = 0.004) cells. Positive correlations were observed between absolute numbers of CD8+IL-10+ and numbers of CD8+IFN-γ+ (p < 0.001) and CD8+TNF-α+ T cells (p ⩽ 0.0001). Finally, an increase in the plasma levels of TNF-α (p = 0.017) and IL-10 (p = 0.006) and a decrease in the IFN-γ plasma level (p <0.0001) were observed in the P. vivaxinfected individuals. Conclusions P. vivax infection reduces the numbers of different subsets of CD8+ T cells, particularly the memory cells, during blood-stage of infection and enhances the number of CD8+ memory T cells expressing IL-10, which positively correlates with the number of cells expressing TNF- α and IFN-γ. [ABSTRACT FROM AUTHOR]

Background The human major histocompatibility complex class I polypeptide-related sequence B (MICB) is a protein that modulates the NK and T cell activation through the NKG2D receptor and is related to several diseases including cancer. Methods The study investigated the prognostic role of soluble MICB (sMICB) protein in the progression of HBV-related liver diseases and to HBV-related HCC treatment. The sMICB serum levels were measured in 266 chronic HBV-infected Vietnamese patients and in healthy controls, and correlated with clinical and laboratory parameters and with therapeutic interventions for HBV-related HCC. Results Significant differences in both clinical and laboratory parameters were observed among the patient groups with different stages of hepatitis. The platelet counts were significantly decreased with disease progression (P < 0.001). The sMICB serum levels were significantly increased in HBV patients compared to healthy controls (P < 0.0001). Among the patients with different stages of hepatitis, asymptomatic individuals (ASYM) revealed higher sMICB serum levels while liver cirrhosis (LC) patients revealed lower sMICB serum levels (P < 0.0001) compared to other patient groups. Notably, the sMICB serum levels were decreased in treated HCC patient group compared to not-treated HCC patient group (P = 0.05). Additionally, the sMICB levels were significantly correlated with platelet counts in ASYM and HCC patients (r = -0.37, P = 0.009; and r = 0.22, P = 0.025, respectively). Conclusions Our results demonstrate a potential role of sMICB serum levels and platelet counts during immune response to the HBV infection, liver disease progression and response to the HCC treatment. [ABSTRACT FROM AUTHOR]

Background Hand, foot and mouth disease (HFMD), a virus-induced infectious disease that usually affects infants and children, has an increased incidence in China in recent years. This study attempted to investigate the role of the Notch signaling pathway in the pathogenesis of HFMD. Methods Eighty-two children diagnosed with HFMD were enrolled into this study. The HFMD group was further divided into the uncomplicated HFMD and HFMD with encephalitis groups. The control group included 40 children who underwent elective surgery for treatment of inguinal hernias. Results Children with HFMD displayed significantly reduced CD3+, CD3+CD4+ and CD3+CD8+ cell subsets, but substantially enhanced CD3-CD19+ cell subset (p < 0.05 versus control subjects). The expression levels of Notch ligands Dll1 and Dll4 in the peripheral blood of the HFMD group were significantly higher than those in the control group (p < 0.05). There were statistically significant differences in CD3+, CD3+CD4+ and CD3-CD19+ cell subsets, but not in Notch ligand expression, between the uncomplicated HFMD and HFMD with encephalitis groups. Dll4 expression in HFMD subjects correlated negatively with the CD3+ and CD3+CD8+ cell subsets (p < 0.05), but positively with the CD3-CD19+ cell subset (p < 0.05). Furthermore, Dll4 expression in HFMD with encephalitis subjects correlated positively with total white blood cell (WBC) counts and total protein contents in cerebrospinal fluid (CSF) (p < 0.05). Conclusions The Notch ligand Dll4 exhibits a strong correlation with the CD3+, CD3+CD8+ and CD3-CD19+ cell subsets in children with HFMD, indicating that the Notch signaling may be involved in the development of HFMD by affecting the number and status of peripheral lymphocytes. [ABSTRACT FROM AUTHOR]

Background Aim of our study is to investigate the clinical and immunological outcomes according to firstline HAART adherence in a large cohort of HIV-infected patients in Burkina Faso. Methods A retrospective study was conducted between 2001 and 2009 among patients from two urban medical centers [St. Camille Medical Center (CMSC) and "Pietro Annigoni" Biomolecular Research Center (CERBA)] and 1 in the rural District of Nanoro (St. Camille District Hospital). Socio-demographical and clinical data were analyzed. Adherence was evaluated through a questionnaire investigating 5 key points related to drugs, consultations and blood exams, by assigning 0 to 2 points each up to 10 points overall. Data were collected at baseline and regularly thereafter. Adherence score was considered as a continuous variable and classified in optimal (8-10 points) and sub-optimal (0-7 points). Immunological outcome was evaluated as modification in CD4+ T-cell count over time, while predictors of death were explored by a univariate and multivariate Cox model considering adherence score as a time-varying covariate. Results A total of 625 patients were included: 455 (72.8%) were females, the median age was 33.3 (IQR 10.2) years, 204 (32.6.%) were illiterates, the median CD4+ T-cell count was 149 (IQR 114) cells/μl at baseline. At the end of the observation period we recorded 60/625 deaths and 40 lost to follow-up. The analysis of immunological outcomes showed a significant variation in CD4+ T-cell count between M12 and M24 only for patients with optimal adherence (Δ=78.2, p<0.001), with a significant Δ between the two adherence groups at M24 (8-10 vs 0-7, Δ=53.8, p=0.004). Survival multivariate analysis revealed that covariates significantly related to death included being followed at CERBA (urban area) or Nanoro (rural area), and receiving a regimen not including fixed dose combinations, (p=0.024, p=0.001 and p<0.001 respectively); conversely, an increasing adherence score as well as an optimal adherence score were significantly related to survival (p<0.001). Conclusions Adherence to HAART remains pivotal to build up a good therapeutic outcome. Our results confirm that, according to our adherence system evaluation, less adherent patients have a higher risk of death and of inadequate CD4+ count recovery. [ABSTRACT FROM AUTHOR]

Background: The 2009 pandemic influenza was milder than expected. Based on the apparent lack of pre-existing cross-protective antibodies to the A (H1N1)pdm09 strain, it was hypothesized that pre-existing CD4+ T cellular immunity provided the crucial immunity that led to an attenuation of disease severity. We carried out a pilot scale study by conducting in silico and in vitro T cellular assays in healthy population, to evaluate the pre-existing immunity to A (H1N1)pdm09 strain. Methods: Large-scale epitope prediction analysis was done by examining the NCBI available (H1N1) HA proteins. NetMHCIIpan, an eptiope prediction tool was used to identify the putative and shared CD4+ T cell epitopes between seasonal H1N1 and A (H1N1)pdm09 strains. To identify the immunogenicity of these putative epitopes, human IFN-γ-ELISPOT assays were conducted using the peripheral blood mononuclear cells from fourteen healthy human donors. All donors were screened for the HLA-DRB1 alleles. Results: Epitope-specific CD4+ T cellular memory responses (IFN-γ) were generated to highly conserved HA epitopes from majority of the donors (93%). Higher magnitude of the CD4+ T cell responses was observed in the older adults. The study identified two HA2 immunodominant CD4+ T cell epitopes, of which one was found to be novel. Conclusions: The current study provides a compelling evidence of HA epitope specific CD4+ T cellular memory towards A (H1N1)pdm09 strain. These well-characterized epitopes could recruit alternative immunological pathways to overcome the challenge of annual seasonal flu vaccine escape. [ABSTRACT FROM AUTHOR]

Background: HIV infection induces chronic immune activation which is associated with accelerated disease progression; the causes of this activation, however, are incompletely understood. We investigated the activation status of CD4+ T cells specific for chronic herpes viruses and the non-persistent antigen tetanus toxoid (TT) in HIV positive and HIV negative donors to assess whether persistent infections contribute to chronic CD4+ T cell activation. Methods: Untreated HIV+ patients and healthy, aged matched controls were recruited and activation levels assessed and compared between cells specific for persistent and non-persistent antigens. Activation levels on antigen-specific CD4+ T cells were measured by intracellular cytokine staining following in vitro stimulation with various recall antigens (CMV, EBV, HSV, VZV and TT) in conjunction with cell surface phenotyping. Results: Activation levels of herpes virus-specific CD4+ T cell populations, assessed by co-expression of CD38 and HLA-DR, were significantly elevated in HIV+ individuals compared to normal controls and compared to TT-specific responses. In contrast, we found similar levels of activation of TT-specific CD4+ T cells in HIV+ and HIV- donors. Conclusions: These results show a disparate distribution of immune activation within CD4+ T cell populations depending on their specificity and suggest that the elevated level of immune activation that characterizes chronic HIV infection may be influenced by the persistence of other antigens. [ABSTRACT FROM AUTHOR]

The article presents a study focusing on the association of placental malaria with attenuated CD4 T-cell responses to tuberculin purified protein derivative (PPD) 12 months after Bacille Calmette-Guérin (BCG) vaccination. It states that placental malaria (PM) is related to prenatal malaise, but several PM+ infants are born without symptoms. It concludes that placental malaria was related to reduced immune responses 12 months after immune challenge in infants apparently healthy at birth.

Background: Viral reservoir size refers to cellular human immunodeficiency virus-1 (HIV-1) DNA levels in CD4+ T lymphocytes of peripheral blood obtained from patients with plasma HIV-1-RNA levels (viral load, VL) maintained below the detection limit by antiretroviral therapy (ART). We measured HIV-1 DNA levels in CD4+ lymphocytes in such patients to investigate their clinical significance. Methods: CD4+ T lymphocytes were isolated from the peripheral blood of 61 patients with a VL maintained at less than 50 copies/ml for at least 4 months by ART and total DNA was purified. HIV-1 DNA was quantified by nested PCR to calculate the copy number per 1 million CD4+ lymphocytes (relative amount) and the copy number in 1 ml of blood (absolute amount). For statistical analysis, the Spearman rank or Wilcoxon signed-rank test was used, with a significance level of 5%. Results: CD4 cell counts at the time of sampling negatively correlated with the relative amount of HIV-1 DNA (median = 33 copies/million CD4+ lymphocytes; interquartile range [IQR] = 7-123 copies/million CD4+ lymphocytes), but were not correlated with the absolute amounts (median = 17 copies/ml; IQR = 5-67 copies/ml). Both absolute and relative amounts of HIV-1 DNA were significantly lower in six patients in whom ART was initiated before positive seroconversion than in 55 patients in whom ART was initiated in the chronic phase, as shown by Western blotting. CD4 cell counts before ART introduction were also negatively correlated with both the relative and absolute amounts of HIV-1 DNA. Only the relative amounts of HIV-1 DNA negatively correlated with the duration of VL maintenance below the detection limit, while the absolute amounts were not significantly correlated with this period. Conclusions: The amounts of cellular HIV-1 DNA in patients with VLs maintained below the detection limit by the introduction of ART correlated with the timing of ART initiation but not with the duration of ART. In addition, CD4+ T lymphocytes, which were newly generated by ART, diluted latently infected cells, indicating that measurements of the relative amounts of cellular HIV-1 DNA might be underestimated. [ABSTRACT FROM AUTHOR]

Background: Concomitant infections may influence HIV progression by causing chronic activation leading to decline in T-cell function. In the Americas, visceral (AVL) and tegumentary leishmaniasis (ATL) have emerged as important opportunistic infections in HIV-AIDS patients and both of those diseases have been implicated as potentially important co-factors in disease progression. We investigated whether leishmaniasis increases lymphocyte activation in HIV-1 co-infected patients. This might contribute to impaired cellular immune function. Methods: To address this issue we analyzed CD4+ T absolute counts and the proportion of CD8+ T cells expressing CD38 in Leishmania/HIV co-infected patients that recovered after anti-leishmanial therapy. Results: We found that, despite clinical remission of leishmaniasis, AVL co-infected patients presented a more severe immunossupression as suggested by CD4+ T cell counts under 200 cells/mm³, differing from ATL/HIV-AIDS cases that tends to show higher lymphocytes levels (over 350 cells/mm³). Furthermore, five out of nine, AVL/HIVAIDS presented low CD4+ T cell counts in spite of low or undetectable viral load. Expression of CD38 on CD8+ T lymphocytes was significantly higher in AVL or ATL/HIV-AIDS cases compared to HIV/AIDS patients without leishmaniasis or healthy subjects. Conclusions: Leishmania infection can increase the degree of immune system activation in individuals concomitantly infected with HIV. In addition, AVL/HIV-AIDS patients can present low CD4+ T cell counts and higher proportion of activated T lymphocytes even when HIV viral load is suppressed under HAART. This fact can cause a misinterpretation of these laboratorial markers in co-infected patients. [ABSTRACT FROM AUTHOR]

Background: Currently, T-cell based gamma interferon (IFNα) release assays (IGRAs) are acknowledged as the best methods available for the screening of latent tuberculosis infection (LTBI) and also as aid for the diagnosis of active tuberculosis (TB). To our information, the performance of these diagnostic tests has not been evaluated in Ethiopia. Therefore, the intent of this study was to evaluate the performance of QuantiFERON-TB Gold In-Tube (QFTGIT) in patients clinically suspected of active pulmonary TB (PTB) as well as in healthy subjects prior to its utilization for the epidemiological study of active TB and LTBI in Afar pastoralists. Methods: The sensitivity of QFTGIT was evaluated in 140 subjects who were clinically suspected of PTB using the cut-off value recommended by the manufacturer (≥ 0.35 IU/ml) and disease-specific cut-off value. Sputum culture result was used as a gold standard. The specificity of the test was evaluated both in patients and in 55 tuberculin skin test (TST) negative healthy subjects. Results: Out of the 140 study participants, 37 (26.4%) were positive for active PTB by culture. Out of the 37 subjects who had positive results by culture, 6 individuals were HIV-seropositive. Out of the 103 subjects who were negative by culture, 6 subjects had indeterminate results and 21 were HIV-seropositive. The performance of the test was assessed using data from 107 (31 culture positive and 76 culture negative) individuals who were clinically suspected of PTB and HIV-seronegatives. Using the manufacturer recommended cut-off value, the sensitivity of the test was 64.5% (20/31), while its specificity was 36.8% (28/76). The sensitivity of the test was increased to 77.4%, while the specificity was reduced to 23.7% using a cut-off value ≥ 0.1 IU/ml of IFNα as disease-specific cut-off value. In TST negative healthy subjects, the specificity of the test was 58.2%. Conclusion: Our findings revealed a low sensitivity of QFTGIT in the diagnosis of Mycobacterium tuberculosis (Mtb) infection in the present study area using the cut-off value recommended by the manufacturer. Nevertheless, the sensitivity increased from 64.5% to 77.4% by lowering the cut-off value recommended by the manufacturer to ≥ 0.1 IU/ml of IFNα level. Hence, it is of practical importance to evaluate the performance of QFTGIT in population under different settings prior to its application either for the diagnosis of active TB or LTBI. [ABSTRACT FROM AUTHOR]

Background: Individuals infected with human immunodeficiency virus (HIV) have an increased risk of progression to active tuberculosis following Mycobacterium tuberculosis infection. The objective of the study was to determine IFN-γ responses for the detection of latent tuberculosis infection (LTBI) with QuantiFERON-TB GOLD In Tube (QFT-GIT) and T-SPOT.TB in HIV patients, and evaluate the influence of CD4 cell count on tests performance. Methods: We studied 75 HIV patients enrolled for ongoing studies of LTBI with T-SPOT.TB, QFN-G-IT and TST. Mean CD4 cell counts ± standard deviation was 461.29 ± 307.49 cells/μl. Eight patients had a BCG scar. Results: T-SPOT.TB, QFN-G-IT and TST were positive in 7 (9.3%), 5 (6.7%) and 9 (12%) cases, respectively. Global agreement between QFN-G-IT and T-SPOT.TB was 89% (κ = 0.275). The overall agreement of T-SPOT.TB and QFNG- IT with TST was 80.8% (κ = 0.019) and 89% (&3x03BA; = 0.373), respectively. We have found negative IFN-γ assays results among 2 BCG-vaccinated HIV-infected individuals with a positive TST. In non BCG-vaccinated patients, QFN-G-IT and TST were positive in 5 cases (7.5%) and T-SPOT.TB in 7 (10.4%). In contrast, in BCG-vaccinated patients, only TST was positive in 4/8 (50%) of the cases. The differences obtained in the number of positive results between TST and both IFN-γ assays in BCG vaccinated patients were significant (95% CI 3-97%, p = 0.046), however, the confidence interval is very wide given the small number of patients. In patients with CD4< 200, we obtained only one (5%) positive result with T-SPOT.TB; however, QFN-G-IT and TST were negative in all cases. On the contrary, percentages of positive results in patients with CD4> 200 were 10.9% (6/55), 9.1% (5/55) and 16.4% (9/55) with TSPOT. TB, QFN-G-IT and TST, respectively. Conclusions: IFN-γ tests have the benefit over TST that are less influenced by BCG vaccination, consequently they are more specific than TST. Although our number of patients with advance immunosuppression is limited, our study suggests that IFN-γ assays are influenced with level of immunosuppression. The use of IFN-γ assays could be a helpful method for diagnosing LTBI in HIV population. [ABSTRACT FROM AUTHOR]

Background: Immune complex deposition is the accepted mechanism of pathogenesis of VL glomerulopathy however other immune elements may participate. Further in the present study, no difference was seen between immunoglobulin and C3b deposit intensity in glomeruli between infected and non-infected dogs thus T cells, adhesion molecules and parameters of proliferation and apoptosis were analysed in dogs with naturally acquired VL from an endemic area. The dog is the most important domestic reservoir of the protozoa Leishmania (L.) chagasi that causes visceral leishmaniasis (VL). The similarity of VL manifestation in humans and dogs renders the study of canine VL nephropathy of interest with regard to human pathology. Methods: From 55 dogs with VL and 8 control non-infected dogs from an endemic area, kidney samples were analyzed by immunohistochemistry for immunoglobulin and C3b deposits, staining for CD4+ and CD8+ T cells, ICAM-1, P-selectin and quantified using morphometry. Besides proliferation marker Ki-67, apoptosis markers M30 and TUNEL staining, and related cytokines TNF-a, IL-1a were searched and quantified. Results: We observed similar IgG, IgM and IgA and C3b deposit intensity in dogs with VL and non-infected control dogs. However we detected the Leishmania antigen in cells in glomeruli in 54, CD4+ T cells in the glomeruli of 44, and CD8+ T cells in 17 of a total of 55 dogs with VL. Leishmania antigen was absent and T cells were absent/scarse in eight non-infected control dogs. CD 4+ T cells predominate in proliferative patterns of glomerulonephritis, however the presence of CD4+ and CD8+ T cells were not different in intensity in different patterns of glomerulonephritis. The expression of ICAM-1 and P-selectin was significantly greater in the glomeruli of infected dogs than in control dogs. In all patterns of glomerulonephritis the expression of ICAM-1 ranged from minimum to moderately severe and P-selectin from absent to severe. In the control animals the expression of these molecules ranged from absent to medium intensity. It was not observed any correlation between severity of the disease and these markers. There was a correlation between the number of Leishmania antigen positive cells and CD4+ T cells, and between the number of CD4+ T cells and CD8+ T cells. In dogs presenting different histopathological patterns of glomerulonephritis, parameters of proliferation and apoptosis were studied. Ki-67, a proliferative marker, was not detected locally, but fewer apoptotic cells and lower TNF-a expression were seen in infected animals than in non-infected controls. Conclusion: Immunopathogenic mechanisms of VL glomerulonephritis are complex and data in the present study suggest no clear participation of immunoglobulin and C3b deposits in these dogs but the possible migration of CD4+ T cells into the glomeruli, participation of adhesion molecules, and diminished apoptosis of cells contributing to determine the proliferative pattern of glomerulonephritis in VL. [ABSTRACT FROM AUTHOR]

Background: T-cell interferon-gamma release assays (IGRAs) may have a role in the diagnosis of active tuberculosis when evaluating patients for whom standard microbiology has limited sensitivity. Our objective was to examine the accuracy of a commercial IGRA for diagnosis of active tuberculosis in HIV-infected persons. Methods: We enrolled HIV-infected patients admitted to Mulago Hospital in Kampala, Uganda with cough ⩾ 2 weeks. All patients underwent standard medical evaluation. We collected peripheral blood specimens at enrollment and performed a commercial, ELISPOT-based IGRA according to the manufacturer's recommendations. IGRA sensitivity and specificity were determined using mycobacterial culture results as the reference standard. Results: Overall, 236 patients were enrolled. The median CD4+ T-lymphocyte count was 49 cells/μl and 126 (53%) patients were diagnosed with active pulmonary tuberculosis. IGRAs were not performed in 24 (10%) patients due to insufficient mononuclear cell counts. In the remaining 212 patients, results were indeterminate in 54 (25%). IGRAs were positive in 95 of 158 (60%) patients with interpretable results. The proportion of positive test results was similar across CD4+ count strata. IGRA sensitivity was 73% and specificity 54%. IGRA results did not meaningfully alter the probability of active tuberculosis in patients with negative sputum smears. Conclusions: An ELISPOT-based IGRA detected a high prevalence of latent tuberculosis infection in a hospitalized population of tuberculosis suspects with advanced HIV/AIDS but had limited utility for diagnosis of active tuberculosis in a high prevalence setting. Further research is needed to identify stronger and more specific immune responses in patients with active tuberculosis. [ABSTRACT FROM AUTHOR]

Background: The advantage of treatment interruptions (TIs) in salvage therapy remains controversial. Regardless, characterizations of the correlates of CD4 count fall during TI are important to identify since patients with virologic failure commonly stop antiretroviral (ARV) therapy. The objective of this study was to determine the predictive value of pre-TI proliferative capacity and cell surface markers for CD4 count change in HIV-infected patients experiencing virologic failure before undergoing TI. Methods: Peripheral blood mononuclear cells (PBMCs) from 13 HIV-infected patients experiencing virologic failure at baseline time points before the TI were tested for proliferation using the 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution assay and a Gag p55 peptide pool, staphylococcus enterotoxin B (SEB), cytomegalovirus (CMV) recall antigen, and anti-CD3 antibody as stimuli. CD28 and CD57 expression on CD4+ and CD8+ T-cells was measured. Results: The median changes in the CD4+ T-cell count and viral load from baseline to the TI time point corresponding to the CD4 count nadir were -44 cells/mm³ {Interquartile range (IQR) -17,104} and +85,332 copies/mL (IQR +11,198, +283,327), respectively. CD4+ T-cell proliferation to CMV, pre-TI CD4+ T-cell count, and percent CD4+CD57+ cells correlated negatively with CD4 count change during TI (r = -0.59, p = 0.045, r = -0.61, p = 0.030 and r = -0.69, p = 0.0095, respectively; Spearman correlation). The presence of HIV-specific proliferative responses was not associated with a reduced decline in CD4 count during TI. Conclusion: The use of pre-TI immune proliferative responses and cell surface markers may have predictive value for CD4 count decline during TI. [ABSTRACT FROM AUTHOR]

Background: The common response to stopping anti-HIV treatment is an increase of HIV-RNA load and decrease in CD4+, but not all the patients have similar responses to this therapeutic strategy. The aim was to identify predictive markers of CD4+ cell count declines to < 350/µL in CD4-guided antiretroviral treatment interruptions. Methods: 27 HIV-infected patients participated in a prospective multicenter study in with a 24 month follow-up. Patients on stable highly active antiretroviral therapy (HAART), with CD4+ count > 600/µL, and HIV-RNA < 50 copies/ml for at least 6 months were offered the option to discontinue antiretroviral therapy. The main outcome was a decline in CD4+ cell count to < 350/µL. Results: After 24 months of follow-up, 16 of 27 (59%) patients (who discontinued therapy) experienced declines in CD4+ cell count to < 350/µL. Patients with a CD4+ nadir of < 200 cells/µL had a greater risk of restarting therapy during the follow-up (RR (CI95%): 3.37 (1.07; 10.36)). Interestingly, lymphoproliferative responses to Mycobacterium tuberculosis purified protein derivative (PPD) below 10000 c.p.m. at baseline (4.77 (1.07; 21.12)), IL-4 production above 100 pg/ mL at baseline (5.95 (1.76; 20.07)) in PBMC cultured with PPD, and increased IL-4 production of PBMC with p24 antigen at baseline (1.25 (1.01; 1.55)) were associated to declines in CD4+ cell count to < 350/µL. Conclusion: Both the number (CD4+ nadir) and the functional activity of CD4+ (lymphoproliferative response to PPD) predict the CD4+ decrease associated with discontinuation of ART in patients with controlled viremia. [ABSTRACT FROM AUTHOR]

Background: In the setting of highly active antiretroviral therapy (HAART), plasma levels of human immunodeficiency type-1 (HIV-1) rapidly decay to below the limit of detection of standard clinical assays. However, reactivation of remaining latently infected memory CD4+ T cells is a source of continued virus production, forcing patients to remain on HAART despite clinically undetectable viral loads. Unfortunately, the latent reservoir decays slowly, with a half-life of up to 44 months, making it the major known obstacle to the eradication of HIV-1 infection. However, the mechanism underlying the long half-life of the latent reservoir is unknown. The most likely potential mechanisms are low-level viral replication and the intrinsic stability of latently infected cells. Methods: Here we use a mathematical model of T cell dynamics in the setting of HIV-1 infection to probe the decay characteristics of the latent reservoir upon initiation of HAART. We compare the behavior of this model to patient derived data in order to gain insight into the role of low-level viral replication in the setting of HAART. Results: By comparing the behavior of our model to patient derived data, we find that the viral dynamics observed in patients on HAART could be consistent with low-level viral replication but that this replication would not significantly affect the decay rate of the latent reservoir. Rather than low-level replication, the intrinsic stability of latently infected cells and the rate at which they are reactivated primarily determine the observed reservoir decay rate according to the predictions of our model. Conclusion: The intrinsic stability of the latent reservoir has important implications for efforts to eradicate HIV-1 infection and suggests that intensified HAART would not accelerate the decay of the latent reservoir. [ABSTRACT FROM AUTHOR]

Background: To investigate dynamic fluctuations of serum viral load and peripheral T-lymphocyte subpopulations of chronic hepatitis B patients and their correlation during entecavir therapy. Methods: Fifty-five patients received entecavir 0.5 mg/d therapy. Serum HBV DNA load was measured by Real-Time PCR, and the levels of peripheral T-lymphocyte subpopulations by flow cytometry biweekly, every four weeks and every eight weeks during weeks 1-12, 13-24 and 24-48, respectively. Multilevel modelling was used to analyse the relationship between these variables. Results: Of the 55 patients, all HBeAg positive and with detectable HBV DNA, the majority (81.8%) had serum levels of HBV DNA over 107 copies per milliliter. HBV viral load dropped sharply during the first two weeks. In 28 and 43 patients, the level became undetectable from week 24 and 48, respectively. Using pre-therapy level as the reference, a significant decrease in CD8+ T cells and increase in CD4+ T cells were found from week 12. Both parameters and CD4+/CD8+ ratio steadily improved throughout the 48 weeks. Multilevel analyses showed that the level of decrement of HBV DNA was associated with the increment of T-lymphocyte activities only in the later period (4-48 week). After 4 weeks of therapy, for each log10 scale decrement of HBV DNA, the percentage of CD4+ lymphocyte was increased by 0.49 and that of CD8+ decreased by 0.51. Conclusion: T-lymphocyte subpopulations could be restored partially by entecavir treatment in patients with chronic hepatitis B concurrently with reduction of viremia. [ABSTRACT FROM AUTHOR]

Background: The identification of antigens able to differentiate tuberculosis (TB) disease from TB infection would be valuable. Cellular and humoral immune responses to Erp (Exported repetitive protein) - a recently identified M. tuberculosis protein - have not yet been investigated in humans and may contribute to this aim. Methods: We analyzed the cellular and humoral immune responses to Erp, ESAT-6, Ag85B and PPD in TB patients, in BCG+ individuals without infection, BCG+ individuals with latent TB infection (LTBI) and BCG- controls. We used lymphoproliferation, ELISpot IFN-?, cytokine production assays and detection of specific human antibodies against recombinant M. tuberculosis proteins. Results: We included 22 TB patients, 9 BCG+ individuals without TB infection, 7 LTBI and 7 BCGcontrols. Erp-specific T cell counts were higher in LTBI than in the other groups. Erp-specific T cell counts were higher in LTBI subjects than TB patients (median positive frequency of 211 SFC/106 PBMC (range 118-2000) for LTBI subjects compared to 80 SFC/106 PBMC (range 50-191), p =0.019); responses to PPD and ESAT-6 antigens did not differ between these groups. IFN-? secretion after Erp stimulation differed between TB patients and LTBI subjects (p = 0.02). Moreover, LTBI subjects but not TB patients or healthy subjects produced IgG3 against Erp. Conclusion: The frequencies of IFN-γ-producing specific T cells, the IFN-γ secretion and the production of IgG3 after Erp stimulation are higher in LTBI subjects than in TB patients, whereas PPD and ESAT-6 are not. [ABSTRACT FROM AUTHOR]

Background: Cerebrospinal fluid (CSF) pleocytosis may be seen in asymptomatic HIV-infected individuals. This finding complicates interpretation of CSF abnormalities when such individuals are evaluated for other central nervous system infections. The goal of this study was to determine the relationship between CSF pleocytosis, central nervous system (CNS) antiretroviral penetration, adherence to antiretroviral medication regimens, neurological symptoms and performance on neuropsychological tests. Methods: Clinically stable HIV-infected individuals at any peripheral blood CD4+ T cell count or any plasma viral load were asked to attend study visits at entry and every 6 months thereafter for at least one year. At each visit, they underwent a standardized neurological and medication history; neurological examination; a brief neuropsychological test battery: venipuncture; lumbar puncture; and assessment of medication adherence. Generalized estimating equations (GEE) were used to assess the relationships between CSF pleocytosis and other variables. Results: CSF pleocytosis was independently and significantly related to lack of current antiretroviral use (OR 5.9, 95% CI 1.8-18.6, p = 0.003), CD4 count > 200/ul (OR 23.4, 95% CI 3.1-177.3, p = 0.002) and detectable plasma HIV RNA (OR 3.3, 95% CI 1.1-9.4, p = 0.03). At visits where antiretrovirals were used, and taking into account detectable plasma HIV RNA, an antiretroviral regimen that contained two or more agents with good CNS penetration conferred a trend toward lower odds of CSF pleocytosis (OR 0.45, 95% CI 0.18-1.12, p = 0.087). Conclusion: CSF pleocytosis is a characteristic of HIV disease that varies significantly with easily identifiable clinical and laboratory features. Use of antiretroviral agents decreases the odds of pleocytosis. This association may be stronger when the regimen contains two or more agents with good CNS penetration. [ABSTRACT FROM AUTHOR]

Background: Zika virus (ZIKV) infection gained public health concern after the 2015 outbreak in Brazil, when microcephaly rates increased in babies born from infected mothers. It was demonstrated that ZIKV causes a congenital Zika virus syndrome, including various alterations in the development of the central nervous system. Although the infection of cells from the nervous system has been well documented, less is known in respect of ZIKV ability to infect immune cells. Herein, we investigated if peripheral blood mononuclear cells (PBMCs), freshly-isolated from healthy donors, could be infected by ZIKV.Methods: PBMCs from healthy donors were isolated and cultured in medium with ZIKV strain Rio-U1 (MOI = 0.1). Infection was analyzed by RT-qPCR and flow cytometry.Results: We detected the ZIKV RNA in PBMCs from all donors by RT-qPCR analysis. The detection of viral antigens by flow cytometry revealed that PBMC from more than 50% the donors were infected by ZIKV, with CD3+CD4+ T cells, CD3-CD19+ B cells and CD3+CD8+ T cells being, respectively, the most frequently infected subpopulations, followed by CD14+ monocytes. Additionally, we observed high variability in PBMC infection rates among different donors, either by numbers or type infected cells.Conclusions: These findings raise the hypothesis that PBMCs can act as a reservoir of the virus, which may facilitate viral dissemination to different organs, including immune-privileged sites. [ABSTRACT FROM AUTHOR]

Background: CD40, encoded by TNFRSF5, participates in the survival of B cells, process of antigen presentation and generation of CD8+ T cell memory. It also has an important effect on HCV antiviral immune response. This study aims to investigate whether TNFRSF5 gene polymorphisms are associated with HCV infection outcomes among Chinese population.Methods: Three single nucleotide polymorphism (SNPs) (rs1535045, rs1883832, rs4810485) on TNFRSF5 were genotyped by TaqMan assay among Chinese population, including 1513 uninfected subjects, 496 spontaneous viral clearance subjects and 768 persistent HCV-infected subjects. Logistic analysis was used to compare these SNPs among different groups in this cross-sectional study. Functional annotations of the identified SNPs were further evaluated by bioinformatics analysis.Results: After adjusted by age, gender and routes of infection, the results of logistic analysis indicated that individuals carrying rs1535045 T allele had a higher risk to infect HCV compared with C allele (in recessive model, adjusted OR = 1.368, 95%CI = 1.070-1.749, P = 0.012). Subjects carried rs1535045 TT genotype were more likely to infect HCV than wild CC genotype (adjusted OR = 1.397, 95%CI = 1.078-1.809, P = 0.011). For rs1883832, T allele was significantly associated with an increased risk of HCV infection (in recessive model, adjusted OR = 1.337, 95%CI = 1.069-1.673, P = 0.011). Subjects with TT genotype had more possibility to infect HCV (adjusted OR = 1.351, 95%CI = 1.060-1.702, P = 0.015). In the stratified analysis, rs1535045 and rs1883832 were remained in various subgroups and the heterogeneity test showed no pronounced heterogeneity in any pairwise comparison (all P > 0.05). In addition, the results of the cumulative effects showed a tendency of that the more risk alleles (rs1535045 T and rs1883832 T) subjects carried, the more possibility of HCV infection exhibited (P<0.001). In haplotype analyses, compared with the CC haplotype, CT, TC and TT was correlated with an increased risk to infect HCV (P = 0.029, P = 0.047 and P<0.001, respectively).Conclusions: In conclusion, CD40 polymorphisms were significantly associated with the susceptibility to HCV among Chinese populations. [ABSTRACT FROM AUTHOR]