Association of HBsAg levels with differential gene expression in NK, CD8 T, and memory B cells in treated patients with chronic HBV.

Background & Aims: HBsAg secretion may impact immune responses to chronic HBV infection. Thus, therapeutic approaches to suppress HBsAg production are being investigated. Our study aims to examine the immunomodulatory effects of high and low levels of circulating HBsAg and thereby improve our understanding of anti-HBV immunity. Methods: An optimized 10x Genomics single-cell RNA sequencing workflow was applied to blood samples and liver fine-needle aspirates from 18 patients undergoing tenofovir/entecavir (NUC) treatment for chronic HBV infection. They were categorized based on their HBsAg levels: high (920-12,447 IU/ml) or low (1-100 IU/ml). Cluster frequencies, differential gene expression, and phenotypes were analyzed. Results: In the blood of HBV-infected patients on NUC, the proportion of KLRC2+ "adaptive" natural killer (NK) cells was significantly lower in the HBsAg-high group and, remarkably, both KLRC2+ NK and KLRG1+ CD8 T cells display enrichment of lymphocyte activation-associated gene sets in the HBsAg-low group. High levels of HBsAg were associated with mild immune activation in the liver. However, no suppression of liver-resident CXCR6+ NCAM1+ NK or CXCR6+ CD69+ CD8 T cells was detected, while memory B cells showed signs of activation in both the blood and liver. Conclusions: Among NUC-treated patients, we observed a minimal impact of HBsAg on leukocyte populations in the blood and liver. However, for the first time, we found that HBsAg has distinct effects, restricted to NK-, CD8 T-, and memory B-cell subsets, in the blood and liver. Our findings are highly relevant for current clinical studies evaluating treatment strategies aimed at suppressing HBsAg production and reinvigorating immunity to HBV. Impact and implications: This study provides unique insight into the impact of HBsAg on gene expression levels of immune cell subsets in the blood and liver, particularly in the context of NUC-treated chronic HBV infection. It holds significant relevance for current and future clinical studies evaluating treatment strategies aimed at suppressing HBsAg production and reinvigorating immunity to HBV. Our findings raise questions about the effectiveness of such treatment strategies and challenge the previously hypothesized immunomodulatory effects of HBsAg on immune responses against HBV.

MBOAT7 rs641738 Variant Is Not Associated with an Increased Risk of Hepatocellular Carcinoma in a Latin American Cohort.

BACKGROUND: The rs641738 C > T single-nucleotide polymorphism of MBOAT7 has been associated with hepatocellular carcinoma (HCC) and nonalcoholic fatty liver disease (NAFLD). Latin Americans have high rates of HCC and NAFLD, but no assessment between MBOAT7 and HCC has been performed in this population. AIMS: We provide the first assessment of the impact of MBOAT7 on HCC risk in Latin Americans. METHODS: Patients were prospectively recruited into the ESCALON network, designed to collect samples from Latin American patients with HCC in 6 South American countries (Argentina, Ecuador, Brazil, Chile, Peru, and Colombia). A European cohort and the general Hispanic population of gnomAD database were included for comparison. Associations between HCC and MBOAT7 were evaluated using logistic regression. RESULTS: In total, 310 cases of HCC and 493 cases of cirrhosis without HCC were assessed. The MBOAT7 TT genotype was not predictive of HCC in Latin Americans (TT vs CC OR adjusted = 1.15, 95% CI 0.66-2.01, p = 0.610) or Europeans (TT vs CC OR adjusted = 1.20, 95% CI 0.59-2.43, p = 0.621). No significant association was noted on subgroup analysis for NAFLD, viral hepatitis, or alcohol-related liver disease. The TT genotype was increased in the NAFLD-cirrhosis cohort of Latin Americans compared to a non-cirrhotic NAFLD cohort (TT vs CC + CT OR = 2.75, 95% CI 1.10-6.87, p = 0.031). CONCLUSION: The rs631738 C > T allele of MBOAT7 was not associated with increased risk of HCC in Latin Americans or Europeans. An increase in the risk of cirrhosis was noted with the TT genotype in Latin Americans with NAFLD.

Validation and optimization of AFP-based biomarker panels for early HCC detection in Latin America and Europe.

BACKGROUND: HCC is a major cause of cancer death worldwide. Serum biomarkers such as alpha-fetoprotein (AFP), protein induced by vitamin K absence-II, and the Gender, Age, AFP-L3, AFP, Des-gamma-carboxy prothrombin (GALAD) score have been recommended for HCC surveillance. However, inconsistent recommendations in international guidelines limit their clinical utility. METHODS: In this multicenter study, over 2000 patient samples were collected in 6 Latin American and 2 European countries. The performance of the GALAD score was validated in cirrhotic cases, and optimized versions were tested for early-stage HCC and prediagnostic HCC detection. RESULTS: The GALAD score could distinguish between HCC and cirrhosis in Latin American patients with an AUC of 0.76, sensitivity of 70%, and specificity of 83% at the conventional cutoff value of -0.63. In a European cohort, GALAD had an AUC of 0.69, sensitivity of 66%, and specificity of 72%. Optimizing the score in the 2 large multicenter cohorts revealed that AFP-L3 contributed minimally to early-stage HCC detection. Thus, we developed a modified GALAD score without AFP-L3, the ASAP (age, sex, AFP, and protein induced by vitamin K absence-II), which showed promise for early-stage HCC detection upon validation. The ASAP score also identified patients with cirrhosis at high risk for advanced-stage HCC up to 15 months before diagnosis (p < 0.0001) and differentiated HCC from hemangiomas, with a specificity of 100% at 71% sensitivity. CONCLUSION: Our comprehensive analysis of large sample cohorts validates the GALAD score's utility in Latin American, Spanish, and Dutch patients for early-stage HCC detection. The optimized GALAD without AFP-L3, the ASAP score, is a good alternative and shows greater promise for HCC prediction.

Assessment of STAT4 Variants and Risk of Hepatocellular Carcinoma in Latin Americans and Europeans.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. The STAT4 rs7574865 genetic variant has been associated with an increased risk of developing HCC in Asian populations. However, this association has not been studied in Latin America and is poorly assessed in European populations. This case-control study investigated the association between STAT4 rs7574865 and HCC risk in these populations. We evaluated DNA samples from seven medical institutions across six Latin American countries and one Dutch institution in 1060 individuals (344 HCC and 716 controls). STAT4 rs7574865 SNP was genotyped using TaqMan-genotyping assay and analyzed using logistic regression. We found no significant association between the homozygous risk allele (G) of STAT4 and HCC development in either population, with odds ratios (OR) for GG versus TT of 0.85 (CI: 0.48-1.52, p = 0.58) and 0.81 (CI: 0.34-1.93, p = 0.67) for Latin Americans and Europeans respectively. No correlation was found between the risk allele and HCC based on underlying liver disease. However, we found that Latin Americans of European ancestry were more likely to carry the risk allele. Our results suggest that the STAT4 SNP rs7574865 does not influence the risk of developing HCC in Latin American or European populations, highlighting the importance of evaluating genetic risk factors in various ethnic groups and understanding the possible influence of ancestry on the genetic basis of disease.

Single-cell RNA sequencing of liver fine-needle aspirates captures immune diversity in the blood and liver in chronic hepatitis B patients.

BACKGROUND AND AIMS: HBV infection is restricted to the liver, where it drives exhaustion of virus-specific T and B cells and pathogenesis through dysregulation of intrahepatic immunity. Our understanding of liver-specific events related to viral control and liver damage has relied almost solely on animal models, and we lack useable peripheral biomarkers to quantify intrahepatic immune activation beyond cytokine measurement. Our objective was to overcome the practical obstacles of liver sampling using fine-needle aspiration and develop an optimized workflow to comprehensively compare the blood and liver compartments within patients with chronic hepatitis B using single-cell RNA sequencing. APPROACH AND RESULTS: We developed a workflow that enabled multi-site international studies and centralized single-cell RNA sequencing. Blood and liver fine-needle aspirations were collected, and cellular and molecular captures were compared between the Seq-Well S 3 picowell-based and the 10× Chromium reverse-emulsion droplet-based single-cell RNA sequencing technologies. Both technologies captured the cellular diversity of the liver, but Seq-Well S 3 effectively captured neutrophils, which were absent in the 10× dataset. CD8 T cells and neutrophils displayed distinct transcriptional profiles between blood and liver. In addition, liver fine-needle aspirations captured a heterogeneous liver macrophage population. Comparison between untreated patients with chronic hepatitis B and patients treated with nucleoside analogs showed that myeloid cells were highly sensitive to environmental changes while lymphocytes displayed minimal differences. CONCLUSIONS: The ability to electively sample and intensively profile the immune landscape of the liver, and generate high-resolution data, will enable multi-site clinical studies to identify biomarkers for intrahepatic immune activity in HBV and beyond.

Circulating Cytokines Reflect the Etiology-Specific Immune Environment in Cirrhosis and HCC.

Background and Aims: Chronic liver disease­from any etiology­can progress to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). The progression of liver cirrhosis to the end stages of disease is influenced by a variety of factors, including inflammatory cytokines. We pursued a study of cytokine-mediated inflammatory responses in hepatitis B (HBV), hepatitis C (HCV), alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) patients with liver cirrhosis. Methods: Immune profiles were determined through the serum multiplex profiling of >100 cytokines in a 188 cirrhotic patients, 35 healthy controls and 196 early-stage HCC patients. Results: Patients with liver cirrhosis exhibited a vast upregulation of proinflammatory cytokines (p < 0.0001), including those with pro-oncogenic features, when compared to healthy individuals. In contrast to prevailing assumptions, each etiological cause of cirrhosis exhibited a unique cytokine profile in blood. Regardless of antiviral therapy, HBV cirrhosis patients had the largest number of upregulated proinflammatory mediators, compared to HCV, ALD and NAFLD (p < 0.0001). To further evaluate the etiology-dependent modulation of cytokine response in relation to liver cancer, we studied cytokine profiles in early-stage HCC patients strictly stratified by underlying liver disease. We observed unique sets of differentially expressed cytokines in each cohort of early-stage HCC patients of different cirrhosis etiologies. Conclusions: Our findings, therefore, underscore the importance of stratification by the etiological cause of liver cirrhosis in immune-based studies.

Differential gene expression, irrespective of circulating Hepatitis B Surface Antigen levels, between Inactive Carrier and Nucleos(t)ide Analogue-Treated Hepatitis B Virus patients.

Long-term viremia control in chronic HBV patients occurs either spontaneously in inactive carrier (IC) patients or therapy-induced by nucleos(t)ide analogues (NUC). To better understand the characteristics of viremia control, we evaluated gene expression in purified leukocyte subsets from IC versus NUC-treated patients, and evaluated the putative modulatory effects of hepatitis B surface antigen (HBsAg). We observed that gene expression in NUC-treated patients differed markedly from IC patients, especially in dendritic cells, monocytes, and CD8+ T cells, while serum HBsAg levels had little effect. Nevertheless, based on our findings it cannot be excluded that HBsAg may act locally in the infected liver or preferentially affects HBV-specific cells.

Sorted B cell transcriptomes point towards actively regulated B cell responses during ongoing chronic hepatitis B infections.

The natural course of chronic hepatitis B virus (HBV) infections follows distinct clinical disease phases, characterized by fluctuating levels of serum HBV DNA and ALT. The immune cells and their features that govern these clinical disease transitions remain unknown. In the current study, we performed RNA sequencing on purified B cells from blood (n = 42) and liver (n = 10) of healthy controls and chronic HBV patients. We found distinct gene expression profiles between healthy controls and chronic HBV patients, as evidenced by 190 differentially expressed genes (DEG), but also between the clinical phenotypes of a chronic HBV infection (17-110 DEG between each phase). Numerous immune pathways, including the B cell receptor pathway were upregulated in liver B cells when compared to peripheral B cells. Further investigation of the detected DEG suggested an activation of B cells during HBeAg seroconversion and an active regulation of B cell signalling in the liver.

Hepatitis B core-related antigen levels predict recurrence-free survival in patients with HBV-associated early-stage hepatocellular carcinoma: results from a Dutch long-term follow-up study.

Prognosis of hepatitis B (HBV)-associated hepatocellular carcinoma (HCC) is poor due to high rates of HCC recurrence and progression of underlying liver disease. We studied whether serum hepatitis B core-related antigen (HBcrAg) levels could predict HCC recurrence and outcome in HBV associated. Higher HBcrAg levels at HCC diagnosis were independently associated with reduced overall and recurrence-free survival in patients with early, but not advanced, stage HCC.

Association between a progesterone receptor mutation and hepatitis E sero-positivity in liver transplant recipients.

PROBLEM: We investigated if the PROGINS mutation increases the risk of hepatitis E virus (HEV) infection in liver transplant recipients. PROGINS was analyzed through KASP assay; HEV serologies assessed via enzyme-linked immunosorbent assay and multiplex cytokine assays were evaluated in plasma with the ProcartaPlex human immunoassay. Seventy liver transplant recipients were evaluated, of which 23 (33%) were HEV immunoglobuln G (IgG)-positive (HEV+). The frequency of PROGINS in the HEV+ group was 34%, compared with 14% in those that were HEV IgG negative (HEV-). Cytokine measurements in a sub-set of samples from HEV+/PROGINS+ individuals showed decreased plasma levels of monokine induced by gamma interferon, a proliferation-inducing ligand, and stem cell factor, as well as increased levels of eotaxin-3 and interleukin-31 compared with those HEV-/PROGINS- samples. Our findings suggest an association between the PROGINS mutation and seropositivity for HEV in liver transplant recipients with consequent distorted cytokine levels.

Hepatitis B core-specific memory B cell responses associate with clinical parameters in patients with chronic HBV.

BACKGROUND & AIMS: Little is known about the frequency, phenotype and function of HBV-specific B cells during chronic infection. Here we study HBcAg and HBsAg-specific B cells in different clinical phases of a chronic HBV infection. METHODS: We included 118 treatment naïve and 34 nucleos(t)ide analogue-treated patients with chronic HBV and 23 healthy HBsAg-vaccinated controls. Global and HBV-specific B lymphocytes were examined by FACS using fluorescently labeled HBsAg and HBcAg as baits. Functional HBV-specific B cell responses were quantified in B cell ELISPOT assays. Anti-HBs and anti-HBc antibodies were measured in serum and in ELISPOT supernatant by ELISA. RESULTS: Higher HBcAg-directed B cell responses were found in HBV clinical phases with elevated vs. low serum alanine aminotransferase (ALT) levels, irrespective of the HBeAg-status. In contrast, HBsAg-directed responses were lower and did not significantly fluctuate. In individual patients a mean 17.8-fold more circulating B cells target HBcAg than HBsAg baits. These HBcAg-specific B cells present a classical memory B cell profile and have slightly higher CD69 expression levels compared to global memory B cells. Viral suppression and ALT normalization upon treatment led to a numeric and functional reduction of HBcAg-specific B cell responses, accompanied by progressive decreases in serum anti-HBc antibodies. CONCLUSION: HBcAg-specific memory B cells present a classical memory B cell phenotype, vary in number and function throughout HBV's natural history and are significantly reduced during antiviral treatment. LAY SUMMARY: In recent years, studies examining the role of B cells during chronic hepatitis B virus infection have regained interest. We show that circulating B cells more often target the hepatitis B core antigen than the hepatitis surface antigen. Moreover, these hepatitis B core-specific B cells associate with the natural history of chronic HBV, and their responses decline during effective antiviral treatment.

Immune dissociation during acute hepatitis E infection.

OBJECTIVE: We report the immune response during a case of acute HEV response in a patient with an acute hepatitis E virus (HEV) genotype 3 infection in the Netherlands. METHODS: Cytokine evaluation was performed via multiplex cytokine array for 65 immune markers in plasma during the different phases of hepatitis. RESULTS: The patient initially presented with features typical of acute viral hepatitis, with detectable HEV RNA in blood. This evolved into a cholestatic disease following peripheral clearance of the virus, leading to the demise of the patient. Real time PCR revealed the presence of HEV in liver tissue, suggestive of active intrahepatic infection despite clearance in blood. During the phase of detectable HEV RNA in serum, there was a surge in T-cell-related immune mediators, as well as interferon alpha and interferon gamma-induced protein 10 (IP-10), characteristic of a viral infection. After clearance of the virus in the blood and development of cholestatic hepatitis, several inflammatory markers subsided, followed by an increase in immune factors related to anti-inflammatory activity, as well as monocyte/macrophage-related markers, likely due to the intrahepatic presence of the virus. CONCLUSIONS: This report describes the dissociation of intra- and extra-hepatic immune responses during acute HEV infection. As shedding of the virus became solely intrahepatic, an immune profile reflective of the activity of hepatic resident cells was observed.

Glucan Particles Are a Powerful Adjuvant for the HBsAg, Favoring Antiviral Immunity.

The lack of vaccine adjuvants that are able to induce robust T cell responses fosters the search for more powerful options. Pathogen-like particles are a promising approach. The adjuvant activity of pathogen-like particles is highly influenced by size and surface composition. This study aimed to evaluate the adjuvant potential of two different ß-glucan-based particles, blend chitosan/ß-glucan particles (ChiGluPs), which are positively charged and have mean size of 1276 nm, and neutral yeast-derived glucan particles (GPs), with a mean size of 3 µm. Additionally, chitosan particles (ChiPs) were used to understand the effect of ß-glucan addition (ChiGluPs). Mouse spleen cells responded through the production of either TNF-α or RANTES, following in vitro stimulation with particles containing either ß-glucan (ChiGluPs and GPs) or chitosan (ChiGluPs and ChiPs). Human monocytes responded to all particles through TNF-α secretion. Subcutaneous vaccination of mice with the hepatitis B surface antigen (HBsAg) showed increased serum IgG for all particles compared to HBsAg alone (435-, 4500-, or 2500-fold increase for either ChiPs, ChiGluPs, or GPs). Interestingly, only GPs elicited the secretion of HBsAg-specific Th1, Th2, Th9, Th17, Th22, and Treg-related cytokines. This study demonstrates, for the first time, that GPs can have a significant role against the hepatitis B virus by favoring antiviral immunity.

Genome-wide Association Study Identifies Genetic Variants Associated With Early and Sustained Response to (Pegylated) Interferon in Chronic Hepatitis B Patients: The GIANT-B Study.

BACKGROUND: (Pegylated) Interferon ([Peg]IFN) therapy leads to response in a minority of chronic hepatitis B (CHB) patients. Host genetic determinants of response are therefore in demand. METHODS: In this genome-wide association study (GWAS), CHB patients, treated with (Peg)IFN for at least 12 weeks ± nucleos(t)ide analogues within randomized trials or as standard of care, were recruited at 21 centers from Europe, Asia, and North America. Response at 24 weeks after (Peg)IFN treatment was defined as combined hepatitis B e antigen (HBeAg) loss with hepatitis B virus (HBV) DNA <2000 IU/mL, or an HBV DNA <2000 IU/mL for HBeAg-negative patients. RESULTS: Of 1144 patients, 1058 (92%) patients were included in the GWAS analysis. In total, 282 (31%) patients achieved the response and 4% hepatitis B surface antigen (HBsAg) loss. GWAS analysis stratified by HBeAg status, adjusted for age, sex, and the 4 ancestry components identified PRELID2 rs371991 (B= -0.74, standard error [SE] = 0.16, P = 3.44 ×10-6) for HBeAg-positive patients. Importantly, PRELID2 was cross-validated for long-term response in HBeAg-negative patients. G3BP2 rs3821977 (B = 1.13, SE = 0.24, P = 2.46 × 10-6) was associated with response in HBeAg-negative patients. G3BP2 has a role in the interferon pathway and was further examined in peripheral blood mononuclear cells of healthy controls stimulated with IFNα and TLR8. After stimulation, less production of IP-10 and interleukin (IL)-10 proteins and more production of IL-8 were observed with the G3BP2 G-allele. CONCLUSIONS: Although no genome-wide significant hits were found, the current GWAS identified genetic variants associated with (Peg)IFN response in CHB. The current findings could pave the way for gene polymorphism-guided clinical counseling, both in the setting of (Peg)IFN and the natural history, and possibly for new immune-modulating therapies. CLINICAL TRIALS REGISTATION: NCT01401400.

TLR7 polymorphism, sex and chronic HBV infection influence plasmacytoid DC maturation by TLR7 ligands.

TLR7 agonists are of high interest for the treatment of cancer, auto-immunity and chronic viral infections. They are known to activate plasmacytoid dendritic cells (pDCs) to produce high amounts of Type I Interferon (IFN) and to facilitate T and B cell responses, the latter with the help of maturation markers such as CD40, CD80 and CD86. The TLR7 single nucleotide polymorphism (SNP) rs179008 (GLn11Leu), sex and chronic viral infection have all been reported to influence pDC IFN production. It is unknown, however, whether these factors also influence pDC phenotypic maturation and thereby IFN-independent pDC functions. Furthermore, it is unclear whether SNP rs179008 influences HBV susceptibility and/or clearance. Here we investigated whether the SNP rs179008, sex and HBV infection affected phenotypic maturation of pDCs from 38 healthy individuals and 28 chronic HBV patients. In addition, we assessed SNP prevalence in a large cohort of healthy individuals (n = 231) and chronic HBV patients (n = 1054). Consistent with previous reports, the rs179008 variant allele was largely absent in Asians and more prevalent in Caucasians. Among Caucasians, the SNP was equally prevalent in healthy and chronically infected males. The SNP was, however, significantly more prevalent in healthy females than in those with chronic HBV infection (42 versus 28%), suggesting that in females it may offer protection from chronic infection. Ex vivo experiments demonstrated that induction of the co-stimulatory molecules CD40 and CD86 by TLR7 ligands, but not TLR9 ligands, was augmented in pDCs from healthy SNP-carrying females. Furthermore, CD80 and CD86 upregulation was more pronounced in females independent of the SNP. Lastly, our data suggested that chronic HBV infection impairs pDC maturation. These findings provide insight into factors determining TLR7 responses, which is important for further clinical development of TLR7-based therapies.

A mutation in the progesterone receptor predisposes to HEV infection in HIV-positive patients.

BACKGROUND AND AIMS: Infection with Hepatitis E virus (HEV) can cause chronic liver disease in immunocompromised hosts. In transplant recipients, the use of certain immunosuppressants and food habits has been proposed as risk factors for HEV. In individuals infected with the human immunodeficiency virus (HIV), risk factors for HEV infection are less clear. We aimed to study the association between a mutation in the progesterone receptor (PR) named PROGINS and HEV-infected in HIV-positive individuals. METHODS: We evaluated the presence of the SNP PROGINS via KASP in serum samples of 64 HIV-positive individuals and 187 healthy controls. We performed ELISA tests to address the serum levels of IL-10 and IL-12, as well as T-cell stimulation assays in peripheral blood to address immune response in individuals with PROGINS. RESULTS: We found a significant association between the presence of PROGINS mutation and HEV seroprevalence in individuals infected with HIV (30% in HIV+/HEV+ versus 2% in HIV+/HEV, respectively, P = .009). Moreover, we found that HIV+/HEV+ individuals expressing the PROGINS mutation had lower serum levels of IL-10 and higher levels of IL-12. The presence of the mutation led to a reduced response upon stimulation of CD4+ and CD8+ T cells compared to those without the mutation, suggesting an immune modulation associated with PROGINS. CONCLUSIONS: Our study identified a mutation in the PR that provides significant insights into mechanisms of HEV infection in immunosuppressed individuals.

Levels of Cytokines in Serum Associate With Development of Hepatocellular Carcinoma in Patients With HCV Infection Treated With Direct-Acting Antivirals.

Concern has arisen about the development of hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV) infection treated with direct-acting antivirals (DAAs). To identify patients at risk for HCC, we evaluated serum levels of immune mediators before, during, and after DAA treatment of HCV infection. Our study included 13 patients who developed HCC within 18 months after treatment (3 with HCC recurrence and 10 with new HCC) and 10 patients who did not develop HCC (controls), within at least 24 months of treatment (median, 26 months). We identified a set of 12 immune mediators (cytokines, growth factors, and apoptosis markers) whose levels were significantly higher in serum before DAA treatment of patients who eventually developed de novo HCC compared with controls. A panel of 9 cytokines, measured in serum before treatment (MIG, IL22, TRAIL, APRIL, VEGF, IL3, TWEAK, SCF, IL21), identified patients who developed de novo HCC with an area under the receiver operating characteristic curve value higher than 0.8. Further analyses of changes in levels of inflammatory cytokines during DAA treatment also provides important information about HCV-induced carcinogenesis and the effects of DAAs.

Immune activation in prolonged cART-suppressed HIV patients is comparable to that of healthy controls.

Sustained immune activation during chronic HIV infection is considered to augment co-morbidity and mortality. Effective combination antiretroviral therapy (cART) has shown to dampen immune activation especially during the first year cART, but the effects of long-term cART in patients without major comorbidities remains under-investigated. We performed a comprehensive analysis including cellular, intracellular and plasma biomarkers to study the effect of cART on immune parameters in 5 groups of 10 HIV patients. All patients were without major co-morbidities and grouped based on cART duration (0, 1, 3, 5, and 10 years). We included 10 matched healthy controls for comparison. Our data show that after the first year of cART, no additional effect on the level of inflammatory markers is observed in HIV infected patients without major co morbidities. Residual immune activation status in well-treated HIV-infection is similar to levels observed in healthy controls.

Decreased pro-inflammatory immune responses during recurrent acute HCV infections in HIV co-infected patients.

Patients in high-risk groups continue to transmit the hepatitis C virus (HCV) and frequently experience reinfections. Since little is known regarding the immune response to HCV during reinfection, we compared primary and consecutive acute HCV infections in patients with an HIV infection, and focused on the cytokine bridging innate to adaptive immunity. We observed that the serum levels of IL-12p40, MIP-1ß, MIG and IP-10 increased during primary acute HCV infection, but not during subsequent secondary acute reinfections. The weaker pro-inflammatory cytokine responses observed during HCV reinfections suggest more limited secondary acute immune responses, which may prevent damage to the infected liver.

NK cell phenotypic and functional shifts coincide with specific clinical phases in the natural history of chronic HBV infection.

BACKGROUND: Chronic HBV infection can be divided into 4 distinct clinical phases: immune tolerant, immune active, inactive carrier, and HBeAg-negative hepatitis. Using a systems biology approach, we recently identified innate immune response components, specifically NK cells as a distinctive factor of specific HBV clinical phases. To expand on this study and identify the underlying immunological mechanisms, we performed a comprehensive profiling of NK cells in chronic HBV infection. METHODS: Peripheral blood from untreated chronic HBV patients was used to analyze phenotypic markers, as well as cytokine production and cytoxicity of NK cells. RESULTS: The overall composition, phenotype, and cytolytic activity of the NK cells remained constant across all clinical phases, with the exception of a few specific markers (KIRs, NKp46). CD56bright NK cells of chronic HBV patients differed in their ability to produce IFN-γ between the clinical phases pre- and post-HBeAg seroconversion. CONCLUSION: This depicts a shift in NK cell characteristics between the immune active, under heavy viral or immune pressure, and inactive carrier phases, that coincides with HBeAg seroconversion. Although these changes in NK cells do not appear to be completely responsible for differences in liver damage characteristic of specific clinical phases, they could provide a step toward understanding immune dysregulation in chronic HBV infection.