Search

Hepatitis C virus (HCV) viremia is thought to have broad systemic effects on the cellular immune system that go beyond its impact on just those T cells that are HCV specific. However, previous studies of chronic HCV and circulating T-cell subsets (activation and differentiation phenotypes) in HIV negatives used general population controls, rather than a risk-appropriate comparison group. Studies in HIV positives did not address overall immune status (total CD4+ count).We used fresh blood from HIV-positive and at-risk HIV-negative women, with and without chronic HCV, to measure percentages of activated CD4+ and CD8+ T cells, Tregs, and T-cell differentiation phenotypes (naive, central memory, effector memory (EM), and terminally differentiated effector). This included 158 HIV negatives and 464 HIV positives, of whom 18 and 63, respectively, were HCV viremic.In multivariate models of HIV negatives, HCV viremia was associated with 25% fewer naive CD4+ (P = 0.03), 33% more EM CD4+ (P = 0.0002), and 37% fewer central memory CD8+ (P = 0.02) T cells. Among HIV positives, we observed only 1 of these 3 relationships: higher percentage of EM CD4+ among HCV viremic women. Furthermore, the association with EM CD4+ among HIV positives was limited to individuals with diminished immune status (total CD4+ count 500 cells/μL), as were associations of HCV viremia with higher percentages of activated CD4+ and Tregs. Among HIV positives with high CD4+ count, no significant associations were observed.These data suggest that HCV viremia in HIV negatives is associated with accelerated T-cell differentiation, but among HIV positives, the impact of HCV viremia is less straightforward and varies by total CD4+ count. [ABSTRACT FROM AUTHOR]

HIV/hepatitis C virus (HCV)-coinfected patients have accelerated liver disease compared with HCV monoinfection. In HIV-positive patients with viral suppression, data comparing inflammatory cytokines and immune activation between HIV/HCV coinfection with chronic hepatitis C (CHC) to HIV/HCV-seropositive patients with cleared HCV are limited.Fifty-nine age- and sex-matched patients were stratified: (1) HIV monoinfection (n = 15); (2) HCV monoinfection with CHC (n = 15); (3) HIV/HCV coinfection with CHC (n = 14); and (4) HIV/HCV seropositive with cleared HCV (n = 15). All HIV-positive patients had undetectable HIV viremia, and median CD4 was 420 cells per microliter. Liver fibrosis was assessed in each subject using transient elastography. Cells were collected for CD4 and CD8 immune activation (CD38/HLA-DR) markers via flow cytometry and plasma for luminex-multiplex cytokine assays.CD38+HLA-DR+ expression on CD4+ T cells was significantly increased in HIV/HCV coinfection with CHC (7%) versus HCV monoinfection (4%) (P = 0.012). CD4+ total HLA-DR+ expression was significantly increased in HIV/HCV coinfection with CHC (43%) versus HIV monoinfection (31%) (P = 0.010) and HIV/HCV seropositive with cleared HCV (38%) (P = 0.046). Total CD4+CD38+ and CD4+CD38+HLA-DR- expression was significantly higher in HIV monoinfection (23% and 18%) than HCV moninfection (13%, P = 0.002% and 9%, P = 0.001, respectively). Interleukin 10 levels were significantly lower in HIV monoinfection versus HIV/HCV coinfection with CHC (P = 0.0002). In multivariate analysis, severe fibrosis was associated with lower expression of CD4+CD38+HLA-DR+ and CD4+ total CD38+ than mild-moderate fibrosis (P = 0.03 and 0.03, respectively).CD4 immune activation with HLA-DR+ expression in HIV/HCV coinfection with well-controlled HIV may arise from chronic HCV viremia. Conversely, CD4+CD38+ expression may be driven by underlying HIV infection. CD4 immune activation was unexpectedly found to be associated with decreased liver fibrosis. [ABSTRACT FROM AUTHOR]

Background: Atherosclerosis is characterized by infiltration of monocytes into the arterial wall, where they form atherosclerotic plaque. The inflammation pathways leading to cardiovascular disease through atherosclerosis may involve monocyte and macrophage activity in response to viral infection, including HIV and hepatitis C virus (HCV). We examined the association of three plasma markers of monocyte and macrophage activity, galectin-3 binding protein (Gal-3BP), soluble CD163 (sCD163), and soluble CD14 (sCD14), with subclinical atherosclerosis, in a subset of women participating in the Women's Interagency HIV Study (WIHS). We hypothesized that higher levels are associated with greater disease. Methods: The WIHS is a longitudinal study of HIV-infected and -uninfected women from 6 U.S. sites. We analyzed 4 groups of 66 women each: HIV+/HCV+, HIV+/HCV-, HIV-/HCV+, and HIV-/HCV-, matched by age, race/ethnicity, and smoking status. Carotid artery B-mode ultrasound assessed two measures of subclinical atherosclerosis: distensibility (in 10 *m /N) and presence of atherosclerotic plaque (IMT >1.5 mm). We created an inflammatory macrophage score (sum of the presence of plasma levels above the median for each marker, range 0-3) and assessed its independent cross-sectional association with subclinical CAD, using regression models with generalized estimating equations to take into account the matched design and controlling for known risk factors. We also assessed associations of Gal-3BP, sCD163, and sCD14 plasma levels individually with subclinical atherosclerosis. Results: 264 women were included (median age 46 [IQR 41-50], 62% black, 26% Hispanic, median distensibility 15.22 [IQR 11.05-21.76]). In models accounting for age, race/ethnicity, smoking, BMI, and CRP, higher macrophage scores were significantly associated with both a 1.5-fold greater odds of plaque (per elevated marker, 95% CI 1.06 to 2.09) and lower distensibility (β -1.40 units per marker, 95% CI -2.62 to -0.17). Gal-3BP alone was associated with both outcomes in adjusted analyses (ORplaque 1.51 per SD of Gal-3BP, 95% CI 1.01 to 2.26; βdistensibility -1.48 units per SD, 95% CI -2.37 to -0.58). sCD163 was associated with a greater odds of plaque only (OR 1.90 per SD, 95% CI 1.16 to 3.12), while sCD14 was associated with lower distensibility (β -1.09 units per SD, 95% CI -2.14 to -0.03). When we stratified by HIV and HCV status, Gal-3BP levels were higher among HCV+ women than HCV- women (mean 12.4 vs. 8.6 µg/mL, p<0.01), but did not differ by HIV status (mean 10.3 vs. 10.7 µg/mL, p=0.34). HIV+/HCV+ women had the highest levels of sCD163 and sCD14. Conclusions: Our data show that the macrophage inflammatory markers Gal-3BP, sCD163 and sCD14 are associated with subclinical carotid atherosclerosis in the setting of HIV and HCV infection. HCV infection may be more strongly associated with these markers than HIV infection. [ABSTRACT FROM AUTHOR]