Search

Background: Cryptococcal meningitis (CM) is a major cause of death in HIV-infected patients in sub-Saharan Africa. Many CM patients experience cryptococcosis-associated immune reconstitution inflammatory syndrome (C-IRIS), which is often fatal. We sought to identify transcriptomic biomarker pathways in peripheral blood that are associated with or predict the development of death or fatal C-IRIS among patients with CM who were enrolled in the Cryptococcal Optimal ART Timing Trial., Methods: We assessed peripheral blood gene expression using next-generation RNA sequencing in 4 groups of patients with CM: (1) no C-IRIS or Death; (2) C-IRIS survivors; (3) fatal C-IRIS; (4) Death without C-IRIS. Gene expression was assessed at the time of ART initiation, at 1, 4, and 8 weeks on ART, and at the time of C-IRIS events., Results: We identified 12 inflammatory and stress response pathways, including interferon type 1 signaling, that were upregulated at the time of ART initiation in patients with future fatal C-IRIS, as compared with survivors. The upregulation of transcripts involved in innate immunity (inflammasome, Toll-like receptor signaling), was observed at the time of fatal or nonfatal C-IRIS events. At the time of fatal C-IRIS events, numerous transcripts within fMLP, Rho family GTPases, HMGB1, and other acute phase response signaling pathways were upregulated, which reflects the severity of inflammation and systemic oxidative stress. Patients who died without recognized C-IRIS also had increased expression of pathways associated with oxidative stress and tissue damage., Conclusions: Our results showed that overactivated innate immunity, involving Toll-like receptor/inflammasome pathways, and inflammation-induced oxidative stress, are associated with fatal outcomes. The results of this study provide insight into the molecular drivers of death and fatal C-IRIS to inform future diagnostic test development or guide targeted treatments.

Background: Tuberculosis (TB) and AIDS are the leading causes of infectious disease death worldwide. In some TB-HIV co-infected individuals treated for both diseases simultaneously, a pathological inflammatory reaction termed immune reconstitution inflammatory syndrome (IRIS) may occur. The risk factors for IRIS are not fully defined. We investigated the association of HLA-B, HLA-C, and KIR genotypes with TB, HIV-1 infection, and IRIS onset., Methods: Patients were divided into four groups: Group 1- TB+/HIV+ (n = 88; 11 of them with IRIS), Group 2- HIV+ (n = 24), Group 3- TB+ (n = 24) and Group 4- healthy volunteers (n = 26). Patients were followed up at INI/FIOCRUZ and HGNI (Rio de Janeiro/Brazil) from 2006 to 2016. The HLA-B and HLA-C loci were typed using SBT, NGS, and KIR genes by PCR-SSP. Unconditional logistic regression models were performed for Protection/risk estimation., Results: Among the individuals with TB as the outcome, KIR2DS2 was associated with increased risk for TB onset (aOR = 2.39, P = 0.04), whereas HLA-B*08 and female gender were associated with protection against TB onset (aOR = 0.23, P = 0.03, and aOR = 0.33, P = 0.01, respectively). Not carrying KIR2DL3 (aOR = 0.18, P = 0.03) and carrying HLA-C*07 (aOR = 0.32, P = 0.04) were associated with protection against TB onset among HIV-infected patients. An increased risk for IRIS onset was associated with having a CD8 count ≤500 cells/mm 3 (aOR = 18.23, P = 0.016); carrying the KIR2DS2 gene (aOR = 27.22, P = 0.032), the HLA-B*41 allele (aOR = 68.84, P = 0.033), the KIR2DS1 + HLA-C2 pair (aOR = 28.58, P = 0.024); and not carrying the KIR2DL3 + HLA-C1/C2 pair (aOR = 43.04, P = 0.034), and the KIR2DL1 + HLA-C1/C2 pair (aOR = 43.04, P = 0.034), CONCLUSIONS: These results suggest the participation of these genes in the immunopathogenic mechanisms related to the conditions studied. This is the first study demonstrating an association of HLA-B*41, KIR2DS2, and KIR + HLA-C pairs with IRIS onset among TB-HIV co-infected individuals.

Aim: Co-infection in HIV-1 patients with Mycobacterium tuberculosis poses considerable risk of developing the immune reconstitution inflammatory syndrome (IRIS), especially upon the initiation of antiretroviral therapy (ART). Methodology & results: For transcriptomic analysis, peripheral blood mononuclear cells' whole gene expression was used from three patient groups: HIV + (H), HIV-TB + (HT), HIV-TB + with IRIS (HTI). Pathway enrichment and functional analysis was performed before and after highly active ART. Genes in the interferon-stimulating and ZNF families maintained tight functional interaction and tilted the balance in favor of TB-IRIS., Discussion & Conclusion: The functional impairment of interaction between ZNF genes and interferon-stimulated genes, along with higher expression of S100A8/S100A9 genes possibly forms the genomic basis of TB-IRIS in a subset of HIV patients while on highly active ART.

Patients with HIV-associated tuberculosis (TB) initiating antiretroviral therapy (ART) may develop immune reconstitution inflammatory syndrome (TB-IRIS). No biomarkers for TB-IRIS have been identified and the underlying mechanisms are unclear. Here we perform transcriptomic profiling of the blood samples of patients with HIV-associated TB. We identify differentially abundant transcripts as early as week 0.5 post ART initiation that predict downstream activation of proinflammatory cytokines in patients who progress to TB-IRIS. At the characteristic time of TB-IRIS onset (week 2), the signature is characterized by over-representation of innate immune mediators including TLR signalling and TREM-1 activation of the inflammasome. In keeping with the transcriptional data, concentrations of plasma cytokines and caspase-1/5 are elevated in TB-IRIS. Inhibition of MyD88 adaptor and group 1 caspases reduces secretion of cytokines including IL-1 in TB-IRIS patients. These data provide insight on the pathogenesis of TB-IRIS and may assist the development of specific therapies.

Background: Human Immunodeficiency Virus (HIV) and Schistosomiasis co-infection is common among residents at the shores of Lake Victoria in Kenya. About 36% of this population initiating antiretroviral therapy (ART) experience Immune Reconstitution Inflammatory Syndrome (IRIS) that complicates recovery. Several IL-23R alleles have been associated with susceptibility to both autoimmune and inflammatory diseases through T-helper type 17 (TH17) cells. However, whether or not variants within the IL-23R increase susceptibility to IRIS in western Kenya is unknown. The objective of the current study was to determine the association between IL-23R gene polymorphisms, CD4+ cell counts and HIV RNA levels and IRIS in HIV and Schistosoma mansoni co-infected patients undergoing highly active anti-retroviral therapy (HAART)., Methods: A three-month case-control study was conducted on antiretroviral naïve schistosomiasis/HIV co-infected fishermen starting HAART in Uyoma Rarieda, Siaya County, Kenya. Seventy one patients were sampled at baseline and followed up for three months, to establish if they developed Schistosoma-related IRIS. In addition, the CD4+ cell counts and HIV RNA levels were determined in pre- and post-administration of HAART. Variations at five polymorphic sites of IL-23R (rs1884444, rs11465754, rs6682925, rs7530511 and rs7539625) based on >10% minor allele frequency in Yoruban reference population was determined using Allelic Discrimination Assay. The association between the five variants and susceptibility to IRIS was determined using logistic regression while controlling for potential confounders. In addition, the functional differences between the baseline CD4 + Cell counts and viral loads were determined using medians while across IL-23R genotypes were determined using Kruskal-Wallis tests., Results: Overall, 26 (36.6%) patients developed schistosomiasis-associated IRIS at a median age of 35.5 years. Carriage of the TT genotype at the non-synonymous rs1884444 T > G relative to GG, was associated with a decreased risk of schistosomiasis-associated IRIS (OR, 0.25, 95% CI, 0.07-0.96, P = 0.043) while both baseline CD4+ cell counts and viral loads had no association with IRIS., Conclusion: These findings indicate that the non-synonymous variant rs1884444 T > G of IL-23R is associated with a decreased risk to schistosomiasis-associated IRIS. However, additional studies in a larger cohort and with an all inclusive polymorphic variants in the synonymous and non-synonymous regions need to be evaluated.

Background: Tuberculosis-associated Immune Reconstitution Inflammatory Syndrome (TB-IRIS) is a common complication of combined antiretroviral therapy (cART) in HIV-TB co-infected patients. However, the disease mechanism is poorly understood, prognosis of TB-IRIS is currently impossible, and diagnosis is highly challenging. We analyzed whether the gene expression of monocytes could be correlated with TB-IRIS pathogenesis and could be used to classify patients predisposed to TB-IRIS., Methods: Monocyte gene expression was compared between patients who developed TB-IRIS and matched controls. We carried out whole-genome expression profiling using Affymetrix GeneChip(®) ST 1.1 arrays at two time-points: before cART initiation (baseline) and at week two post-cART initiation. For each time-point, we used different statistical approaches to identify molecular signatures which could be used as classifiers. We also functionally mapped the modulated cellular pathways using the software package Ingenuity Pathway Analysis., Results: At baseline, before introduction of cART and before onset of symptoms, monocyte gene expression was already perturbed in patients who subsequently developed TB-IRIS, indicating a possible involvement of monocytes in TB-IRIS predisposition. The differences in monocyte gene expression in TB-IRIS patients became even more clear after two weeks of cART (when TB-IRIS commonly occurs), with more than 100 genes for which expression showed a fold change greater than 1.5. Both at baseline and at week two post-cART initiation, a classifier of 8 and 9 genes, respectively could be built, which allowed discrimination of TB-IRIS cases and controls. Pathway analyses revealed that the majority of the dysregulated genes in TB-IRIS - at the time of the IRIS episode, but also already at baseline - are associated with infection and inflammation. Relevant biological functions which were perturbed before/during TB-IRIS included "Role of Pattern Recognition Receptors in Recognition of Bacteria and Viruses" and "Complement System"., Conclusion: Our results indicate an involvement of monocytes in predisposition to/development of TB-IRIS, and suggest a number of functional pathways which may play a role in TB-IRIS development. This comprehensive study of gene regulation in monocytes provides baseline data for further studies into biomarkers for prognosis and diagnosis of TB-IRIS., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Background: Up to 43% of HIV-infected patients co-infected with Mycobacterium tuberculosis experience exacerbations of tuberculosis (TB) after commencing antiretroviral therapy (ART). These are termed immune restoration disease (IRD). It is unclear why individual susceptibility varies., Objective: We investigate if single nucleotide polymorphisms (SNP) in genes encoding cytokines, chemokines and their receptors associate with development of an IRD event in patients of two different ethnicities., Methods: DNA samples were available from small well-characterised groups of HIV patients treated in Cambodia (TB-IRD, n=17; HIV(+)TB(+) controls, n=55) and India (TB-IRD, n=19; HIV(+)TB(+) controls, n= 43). HIV patients with a TB diagnosis but no evidence of IRD were included to control for susceptibility to TB per se. Sixteen SNP implicated in inflammation or mycobacterial disease were genotyped., Results: Susceptibility to TB-IRD associated with carriage of TNFA-1031*T (rs1799964; P=0.05) and SLC11A1 D543N*G (rs17235409; P=0.04) in Cambodian patients and carriage of IL18-607*G (rs1946518; P=0.02) and VDR FokI (F/f)*T (rs10735810; P=0.05) in Indian patients., Conclusions: Associations between polymorphisms in immune-related genes and TB-IRD were found, but none were common across two ethnicities.