Injecting drug use: A vector for the introduction of new hepatitis C virus genotypes

Hepatitis C virus (HCV) genotypes' monitoring allows real-time insight into the dynamic changes that occur in the global epidemiological picture of HCV infection. Intravenous drug use is currently the primary driver for HCV transmission in developed and developing countries. The distribution of HCV genotypes/subtypes differs significantly between people who inject drugs (PWID) and the general population. HCV genotypes that previously exhibited a limited geographical distribution (3a, 4) are becoming more prevalent in this high-risk group. Immigration from HCV-endemic countries and the evolving networks of HCV transmission in PWID influence HCV genotypes distribution in Europe. Social vulnerabilities (e.g., unemployment, homelessness, and limited access to social and healthcare insurances systems) are important triggers for illicit drug use, which increases the associated risks of HCV infection and the frequent emergence of less prevalent genotypes. Genotype/subtype determination bears important clinical consequences in the progression of liver disease, susceptibility to antiviral therapies and the emergence of resistance-associated variants. An estimated half of the chronically HCV-infected PWID are unaware of their infection, and only one in ten of those diagnosed enter treatment. Nevertheless, PWID exhibit high response rates to new antiviral regimens, and the level of HCV reinfection is unexpectedly low. The focus of the healthcare system must be on the early detection and treatment of infection, to avoid late presentations that are associated with high levels of viremia and liver fibrosis, which may diminish the therapeutic success rate.

Trypanosoma cruzi-induced tyrosine phosphorylation in murine peritoneal macrophages

Trypanosoma cruzi, the etiological agent of Chagas' disease, binds to and invades macrophages and other cells (fibroblasts, muscle cells) via a complicated set of interactions, but the changes induced by parasite-to-cell interactions are largely unknown. This report investigates the ability of T. cruzi to elicit a tyrosine kinase pathway in immature and mature resident murine peritoneal macrophages (MPM) that differ in their susceptibility to parasite infection. T. cruzi stimulated the phosphorylation of tyrosine residues in several endogenous substrates (proteins of 40-42, 53-56, 66, 75, 80, 90, 95, 100, and 112 kDa), but only in immature MPM. Mature MPM had high levels of spontaneous tyrosine phosphorylation. Upstream tyrosine kinases, such as src-like tyrosine kinases, were not responsible for the differential patterns of tyrosine phosphorylation since they were present in both mature and immature MPM. We suggest that the tyrosine phosphorylation patterns stimulated by T. cruzi reflect most of the biochemical events that occur in parasite host-cell interactions.

High prevalence of hepatitis B virus markers in Romanian adolescents with human immunodeficiency virus infection

BACKGROUND

We evaluated the frequency of hepatitis coinfection in Romanian adolescents who were diagnosed with human immunodeficiency virus (HIV) infection prior to 1995.

METHODS

One hundred sixty-one adolescents (13-18 years of age) with symptomatic HIV infection, but without signs of hepatic dysfunction, and 356 age-matched, HIV-uninfected controls underwent laboratory testing for markers of parenterally acquired hepatitis virus infection.

RESULTS

Seventy-eight percent of HIV-infected adolescents had markers of past or present hepatitis B virus (HBV) infection, as compared with 32% of controls ( P = .0001). The prevalence of HBV replicative markers was more than 5-fold higher in HIV-infected adolescents as compared with controls: 43.4% vs 7.9% ( P = .0001), respectively, for hepatitis B surface antigen (HBsAg); and 11.2% vs 2.2% ( P = .0001), respectively, for hepatitis B e antigen (HBeAg). The prevalence of HBsAg chronic carriers and the presence of HBV replicative markers was significantly higher in patients with immunologically defined AIDS (CD4+ cell counts < 200 cells/mcL): 59.6% vs 34.6% ( P = .02) for HBsAg and 22.8% vs 5.7 %, ( P = .002) for HBV DNA. After 1 year of follow-up, the proportion of those who cleared the HBeAg was considerably lower in severely immunosuppressed coinfected patients: 4.7% vs 37.1% ( P = .003). Four additional HIV-infected adolescents became HBsAg-positive over the term of follow-up (incidence rate, 24.9/1000 person-years), despite a record of immunization against hepatitis B.

CONCLUSIONS

A substantial percentage of HIV-infected and HIV-uninfected Romanian adolescents have evidence of past or present HBV infection. In HIV-infected adolescents, the degree of immunosuppression is correlated with persistence of HBV replicative markers, even in the absence of clinical or biochemical signs of liver disease.

HCV non-1b genotypes in injecting drug users from Romania

INTRODUCTION

Chronic hepatitis C cases diagnosed in Romania were mostly related to unsafe parenteral treatments and blood transfusions; HCV genotype 1b was prevalent. During the last decade, an increasing number of HCV infections was reported among people who inject drugs (PWID). The aim of the current study was to test if this epidemiological shift triggered a diversification of the circulating viral strains.

METHODOLOGY

HCV genotypes were determined by reverse hybridization in 130 HCV-infected PWID (87.7% males; mean age 27.9 ± 6.7 years, injecting drugs for 8.1 ± 4.8 years).

RESULTS

HIV-HCV co-infection was diagnosed in 80.8% of the subjects and 26.9% were HIV-HCV-HBV triple infected. Active HCV viral replication was present in 104 PWID (80%), more frequently in those HIV-co-infected (91.4% vs. 52% in HCV mono-infected, and 77.148.5% in HIV-HCV-HBV triple-infected, p = 0.0001). Non-1b genotypes were prevalent (54.8%), with subtype 1a the most commonly detected (24%), followed by genotypes 3a (14.4%) and 4 (7.7%). Mixed infections with genotypes 1a and 1b were found in nine subjects (8.7%). There was no difference in the genotypes frequencies based on HIV or HBV co-infection status, length of drug usage, or associated risk factors (tattoos, piercing, detention).

CONCLUSION

The continuous surveillance of HCV genotypes in PWID from Romania will add valuable information to the overall European epidemiological picture, with important therapeutic implications.

HIV-HBV Coinfection-Current Challenges for Virologic Monitoring

HIV-HBV coinfected patients have higher rates of liver-related morbidity, hospitalizations, and mortality compared to HBV or HIV mono-infected ones. Clinical studies have shown an accelerated progression of liver fibrosis and an increased incidence of HCC, resulting from the combined action of HBV replication, immune-mediated hepatocytolysis, and HIV-induced immunosuppression and immunosenescence. Antiviral therapy based on dually active antiretrovirals is highly efficient, but late initiation, global disparities in accessibility, suboptimal regimens, and adherence issues may limit its impact on the development of end-stage liver disease. In this paper, we review the mechanisms of liver injuries in HIV-HBV coinfected patients and the novel biomarkers that can be used for treatment monitoring in HIV-HBV coinfected persons: markers that assess viral suppression, markers for liver fibrosis evaluation, and predictors of oncogenesis.

SARS-CoV-2 Humoral and Cellular Immune Responses in People Living with HIV

Immunosuppressed individuals, such as people living with HIV (PLWH), remain vulnerable to severe COVID-19. We analyzed the persistence of specific SARS-CoV-2 humoral and cellular immune responses in a retrospective, cross-sectional study in PLWH on antiretroviral therapy. Among 104 participants, 70.2% had anti-S IgG antibodies, and 55.8% had significant neutralizing activity against the Omicron variant in a surrogate virus neutralization test. Only 38.5% were vaccinated (8.76 ± 4.1 months prior), all displaying anti-S IgG, 75% with neutralizing antibodies and anti-S IgA. Overall, 29.8% of PLWH had no SARS-CoV-2 serologic markers; they displayed significantly lower CD4 counts and higher HIV viral load. Severe immunosuppression (present in 12.5% of participants) was linked to lower levels of detectable anti-S IgG (p = 0.0003), anti-S IgA (p < 0.0001) and lack of neutralizing activity against the Omicron variant (p < 0.0001). T-cell responses were present in 86.7% of tested participants, even in those lacking serological markers. In PLWH without severe immunosuppression, neutralizing antibodies and T-cell responses persisted for up to 9 months post-infection or vaccination. Advanced immunosuppression led to diminished humoral immune responses but retained specific cellular immunity.