Infectious diseases of the hepatobiliary system

This review will concentrate on commonly encountered infectious diseases in biopsy practice and will consider three scenarios: Firstly, the most frequent, where the biopsy arrives with the infectious disease stated on the request form. Secondly, where the patient has a risk factor placing infectious diseases high in the differential diagnosis and, thirdly, where infection is one of several possible aetiologies when a liver biopsy shows a particular pattern of inflammation.     

Infectious diseases of the hepatobiliary system

This review will concentrate on commonly encountered infectious diseases in biopsy practice and will consider three scenarios: Firstly, the most frequent, where the biopsy arrives with the infectious disease stated on the request form. Secondly where the patient has a risk factor placing infectious diseases high in the differential diagnosis and, thirdly, where infection is one of several possible aetiologies when a liver biopsy shows a particular pattern of inflammation.     

Infectious diseases in humanized mice

Despite many theoretical incompatibilities between mouse and human cells, mice with reconstituted human immune system components contain nearly all human leukocyte populations. Accordingly, several human‐tropic pathogens have been investigated in these in vivo models of the human immune system, including viruses such as human immunodeficiency virus (HIV) and Epstein‐Barr virus (EBV), as well as bacteria such as Mycobacterium tuberculosis and Salmonella enterica Typhi. While these studies initially aimed to establish similarities in the pathogenesis of infections between these models and the pathobiology in patients, recent investigations have provided new and interesting functional insights into the protective value of certain immune compartments and altered pathology upon mutant pathogen infections. As more tools and methodologies are developed to make these models more versatile to study human immune responses in vivo, such improvements build toward small animal models with human immune components, which could predict immune responses to therapies and vaccination in human patients.     

HIV and co-infections

Despite significant reductions in morbidity and mortality secondary to availability of effective combination anti-retroviral therapy (cART), human immunodeficiency virus (HIV) infection still accounts for 1.5 million deaths annually. The majority of deaths occur in sub-Saharan Africa where rates of opportunistic co-infections are disproportionately high. In this review, we discuss the immunopathogenesis of five common infections that cause significant morbidity in HIV-infected patients globally. These include co-infection with Mycobacterium tuberculosis, Cryptococcus neoformans, hepatitis B virus, hepatitis C virus, and Plasmodium falciparum. Specifically, we review the natural history of each co-infection in the setting of HIV, the specific immune defects induced by HIV, the effects of cART on the immune response to the co-infection, the pathogenesis of immune restoration disease (IRD) associated with each infection, and advances in the areas of prevention of each co-infection via vaccination. Finally, we discuss the opportunities and gaps in knowledge for future research.     

Seroepidemiological associations between tuberculosis,malaria, hepatitis B,and AIDS in West Africa

Serum samples from 51 patients with malaria, 35 patients with hepatitis B virus infection, 111 patients with tuberculosis, and 166 healthy controls were studied to determine any associations between tuberculosis, malaria, hepatitis B, and AIDS in Nigeria, West Africa. All serum samples were examined for the presence of HIV-1/HIV-2, hepatitis B virus surface antigen (HBsAg), and malaria antibodies. Only one patient was HIV-1 antibody-positive and none HIV-2 antibody-positive. Statistical associations were found between the presence of malaria antibody litres on the one hand and a diagnosis of hepatitis B virus infection (P < 0.05) or tuberculosis (P < 0.05). A stronger association (P < 0.001) was found between the presence of HBsAg and tuberculosis suggesting that HBsAg carriers are at higher risk of contracting tuberculosis. © 1994 Wiley-Liss, Inc.     

Toll-like receptor 3 polymorphism and its association with hepatitis B virus infection in Saudi Arabian patients

Hepatitis B virus (HBV) is the major causative agent of chronic liver complications including cirrhosis and hepatocellular carcinoma (HCC). Individuals infected with HBV show a wide spectrum of disease manifestations ranging from asymptomatic carriers to HCC. TLR3 is part of the innate immune system that recognizes double‐stranded RNA (dsRNA) and provides early immune response to exogenous antigens. The genetic polymorphisms such as single nucleotide polymorphisms (SNPs) in the TLR3 could be considered as factors for the susceptibility to viral pathogens including HBV. Due to lack of knowledge on the role of TLR3 polymorphisms in HBV infection, this study investigated the distribution of nine SNPs in the TLR3 gene and its association with Saudi Arabian patients infected with HBV. A total of 707 patients and 600 uninfected controls were examined for different parameters including the nine SNPs (rs5743311, rs5743312, rs1879026, rs5743313, rs5743314, rs5743315, rs111611328, rs78726532 and a newly identified SNP located at position 184322913 of chr4). The association analysis confirmed that only one SNP, rs1879026 (G/T), showed a significant difference (P = 0.0480; OR = 0.809, 95% CI = 0.655–0.999) in the distribution between HBV carriers and uninfected controls. While, the rest of the SNPs showed no significant association with regards to HBV infection or in the progression to cirrhosis of the liver and HCC. Furthermore, haplotype analysis revealed that one haplotype GCGA (rs1879026, rs5743313, rs5743314, and rs5743315, respectively), was associated significantly with HBV infection in this population. These findings indicate that genetic variations in the TLR3 gene could affect the outcome of HBV infection among Saudis. J. Med. Virol. 84:1353–1359, 2012. © 2012 Wiley Periodicals, Inc.     

Coinfection between SARS-CoV-2 and vector-borne diseases in Luanda,Angola

Co-epidemics happening simultaneously can generate a burden on healthcare systems. The co-occurrence of SARS-CoV-2 with vector-borne diseases (VBD), such as malaria and dengue in resource-limited settings represents an additional challenge to the healthcare systems. Herein, we assessed the coinfection rate between SARS-CoV-2 and VBD to highlight the need to carry out an accurate diagnosis and promote timely measures for these infections in Luanda, the capital city of Angola. This was a cross-sectional study conducted with 105 subjects tested for the SARS-CoV-2 and VBD with a rapid detection test in April 2021. The participants tested positive for SARS-CoV-2 (3.80%), malaria (13.3%), and dengue (27.6%). Low odds related to testing positivity to SARS-CoV-2 or VBD were observed in participants above or equal to 40 years (odds ratio [OR]: 0.60, p = 0.536), while higher odds were observed in male (OR: 1.44, p = 0.392) and urbanized areas (OR: 3.78, p = 0.223). The overall co-infection rate between SARS-CoV-2 and VBD was 11.4%. Our findings showed a coinfection between SARS-CoV-2 with malaria and dengue, which could indicate the need to integrate the screening for VBD in the SARS-CoV-2 testing algorithm and the adjustment of treatment protocols. Further studies are warranted to better elucidate the relationship between COVID-19 and VBD in Angola.     

Effect of Antiretroviral Therapy and Hepatitis C Co-infection on Changes in Lipid Levels in HIV-Infected Patients 48 Weeks After Initiation of Therapy

Abstract

Hepatitis C virus (HCV) commonly co-infects HIV-infected individuals. Antiretroviral therapy (ART) is associated with elevated serum lipid levels, and HCV infection is associated with low serum lipid levels. Fasting lipid levels were investigated in 1,434 ART-naïve HIV-infected people participating in the AIDS Clinical Trials Group (ACTG) Longitudinal Linked Randomized Trials (ALLRT) protocol who prospectively initiated ART with ≥3 agents. Subjects with elevated liver-associated enzymes (>5 × ULN) were excluded. Demographics, body mass index, HCV status, CD4 cell count, HIV RNA, liver enzymes, lipid levels, and glucose were assessed before and following 48 weeks of ART. HCV-positive subjects (n = 160; 11%) were older, more likely to be Black, have a history of intravenous drug use (IDU), have higher baseline liver-associated enzyme levels than the HCV-negative group (p < .001 for each), and to have diabetes at baseline (5% vs. 2%, p = .07). Lipid levels rose in both groups following ART, and the differences were not significant except that HDL levels increased significantly more in the HCV-positive group (p = .006). In summary, HCV infection did not appear to provide significant protection against ART-induced hyperlipidemia in this cohort of HIV-infected subjects prospectively enrolled in ART trials, although HDL levels rose to a greater degree.     

Lack of association between genotypes and subtypes of HCV and occurrence of hepatocellular carcinoma in Egypt

The distribution of hepatitis C virus (HCV) genotypes was evaluated in individuals with hepatocellular carcinoma (HCC) and cirrhosis in Egypt. A total of 206 patients sero‐positive for HCV‐RNA among 400 surveyed individuals (186 with HCC, 100 with cirrhosis, and 114 healthy volunteers) were analyzed for HCV genotype. Of 206 patients, 129 had HCC, 65 had cirrhosis without HCC, and 12 were healthy volunteers. Phylogenetic analysis of sequence showed that of 206 samples, 186 contained HCV genotype 4 (90.3%), while 20 had HCV genotype 1 (9.7%). Among subjects with genotype 4, subtype 4a was predominant (79%), other subtypes included 4d, 4m, 4n, and 4o. Among those with HCV genotype 1, 15 had subtype 1g and five subtype 1a. Although subtype 4a was noted slightly more frequently in HCC (76%) compared to cirrhosis (66%) and controls (50%), there was no statistically significant difference between these three groups (P = 0.08). In conclusion, HCV genotype 4 predominates in Egypt. There was no association between subtypes of genotype 4 and the development of HCC. J. Med. Virol. 81:844–847, 2009. © 2009 Wiley‐Liss, Inc.     

Translating the role of vitamin D3 in infectious diseases

Vitamin D₃ affects both the innate as well as adaptive immune responses. Epidemiological studies have established that vitamin D₃ deficiency plays an important role in tuberculosis (TB) and viral influenza prevalence as well as susceptibility to active disease in TB. Vitamin D₃ status has been associated with the clinical course of HIV infection and drug interaction with anti-retroviral therapy. This article reviews the immunomodulatory capacity of vitamin D₃ and examines the impact of vitamin D₃ supplementation as a preventive or therapeutic intervention with the intent to uncover its potential therapeutic application in infectious diseases and to identify novel areas for future research. We present a review of randomized, controlled clinical studies conducted in humans which included assessment of the immune function or clinical outcome as study end points. Current data support vitamin D₃ supplementation as risk-modifying intervention in tuberculosis and viral respiratory tract infection, but the optimal dosage regimen remains to be determined. However, to date the knowledge on its role in fungal infection and sepsis is limited although a potential benefit could be harnessed from its ability to curtail the unrestrained pro-inflammatory response and therefore prevent excessive collateral tissue damage.     

Low rates of active hepatitis B and C infections among adults and children living with HIV and taking antiretroviral therapy: A multicenter screening study in Lesotho

Lesotho presents the second-highest adult human immunodeficiency virus (HIV) prevalence globally. Among people living with HIV, data on hepatitis B virus (HBV) or hepatitis C virus (HCV) coinfection are limited. We report HBV and HCV coinfection data from a multicentre cross-sectional study among adult and pediatric patients taking antiretroviral therapy in 10 health facilities in Lesotho. Among 1318 adults screened (68% female; median age, 44 years), 262 (20%) had immunologically controlled HBV infection, 99 (7.6%) tested anti-HBs positive and anti-HBc negative, indicating vaccination, and 57 (4.3%) had chronic HBV infection. Among the patients with chronic HBV infection, 15 tested hepatitis B envelope antigen (HBeAg) positive and eight had detectable HBV viremia (median, 2 477 400 copies/mL; interquartile range, 205-34 400 000) with a mean aspartate aminotransferase-to-platelet ratio index of 0.48 (SD, 0.40). Prevalence of HCV coinfection was 1.7% (22 of 1318), and only one patient had detectable HCV viremia. Among 162 pediatric patients screened, three (1.9%) had chronic HBV infection, whereby two also tested HBeAg-positive, and one had detectable HBV viral load (210 copies/mL). Six of 162 (3.7%) had anti-HCV antibodies, all with undetectable HCV viral loads. Overall prevalence of chronic HBV/HIV and HCV/HIV coinfection among adults and children was relatively low, comparable to earlier reports from the same region. But prevalence of immunologically controlled HBV infection among adults was high. Of those patients with chronic HBV infection, a minority had detectable HBV-DNA.     

Seroprevalence of HIV, syphilis, and hepatitis C virus in the general population of the Liangshan Prefecture, Sichuan Province, China

This study aimed at understanding the HIV prevalence, distribution of HIV risk factors and whether the HIV has spread from high‐risk groups to the general population in the Yanyuan and Muli counties, Liangshan Prefecture, Sichuan Province, China. A multistage probability method was used to select a representative sample of villages in each county, with stratification by risk employed in the sampling for the Yanyuan county. A real‐name registration and confidential method were adopted to collect the information of the participants. Blood specimens were tested for HIV, syphilis, and hepatitis C virus. A total of 4,950 subjects participated in the study. Of the participants aged ≥ 15 years, 0.12% self‐reported being drug users and 40% were injection drug users; 0.46% had multiple sex partners and the condom use rate was only 26.3% during the last sexual intercourse. HIV, syphilis, and HCV prevalence of Yanyuan county were 0.06% (95% CI: 0–0.142), 0.06% (95% CI: 0–0.142), and 0.15% (95% CI: 0.020–0.280), respectively. HCV prevalence of Muli county was 0.06% (95% CI: 0–0.191), and none was found to be HIV or syphilis positive. Therefore, the rate of HIV infection in Yanyuan and Muli counties is at a low level currently. The Yanyuan county HIV infection rate is similar to the average rate in all of China, and the Muli county rate is below China's average. The HIV epidemic has not spread from high‐risk groups to the general population in these two counties. J. Med. Virol. 84:1–5, 2011. © 2011 Wiley Periodicals, Inc.     

Serologic markers of viral hepatitis A,B, C,and D in patients with hemophilia

Forty-one patients with hemophilia A were studied for the prevalence of serological markers for hepatitis A, hepatitis B, hepatitis C (non-A and non-B hepatitis), and delta hepatitis (hepatitis D). Ten of 41 (24.4%) patients demonstrated hepatitis A antibody and 31 of 41 (75.6%) patients had a serologic marker for previous hepatitis B infection; four of these 31 patients (13%) also demonstrated antibody to delta agent (hepatitis D). Thirty-seven of 41 (90.2%) patients demonstrated antibody for hepatitis C. Nine of 31 (29%) patients with a hepatitis B marker (no hepatitis B vaccinees) were negative for anti-HBc but positive for anti-HBs; all of these nine patients were HIV antibody positive, although they had no overt immunodeficiency. Twenty-six of 41 (63.5%) patients were HIV antibody positive. Of HIV antibody positive patients, 27%, 88%, and 100% demonstrated evidence of a previous hepatitis A, hepatitis B, or hepatitis C, respectively. Of HIV antibody negative patients; 20%, 53%, and 73% of the patients demonstrated evidence of a previous hepatitis A, hepatitis B, or hepatitis C infections, respectively. The difference between HIV antibody positive and HIV antibody negative groups was not significant for hepatitis A but was significant for hepatitis B (P < 0.001) and hepatitis C (P < .001). Of the 31 patients with a hepatitis B serologic marker, all had antibody to hepatitis C. Of 10 patients, without a hepatitis B serologic marker, only 6 (60%) had antibody to hepatitis C. Clinically, none of our patients demonstrated any evidence of liver disease; however, 10 patients reported a previous history of hepatitis. These data suggest that patients with hemophilia in the United States, particularly those with HIV antibody, have high prevalence of hepatitis B and C infections.     

Autoantibodies to malondialdehyde-modified epitope in connective tissue diseases and vasculitides.

Tuberculosis is characterized by fever, weight loss, a prolonged acute-phase protein response and granuloma formation. These characteristics may partly be due to action of proinflammatory cytokines tumour necrosis factor (TNF), IL-6 and IL-8. We investigated plasma concentrations of these cytokines before and after ex vivo lipopolysaccharide stimulation of whole blood leucocytes from 41 Zambian patients with tuberculosis, 32 of whom were also HIV+. Although patients had a reduced weight, were more anaemic and had higher erythrocyte sedimentation rate compared with controls (all P < 0.0005), clinical and laboratory measurements of disease state were similar in those who died and survivors. In contrast, plasma IL-6 and IL-8 concentrations were higher in patients who died (P < 0.05). There was no detectable cytokine mRNA in unstimulated leucocytes. There was reduced secretion of TNF (P < 0.005 at 2 h), IL-6 (P < 0.005 at 8 h) and IL-8 (P < 0.005 at 24 h) after ex vivo stimulation of whole blood leucocytes from patients who died compared with survivors. This was partly due to a soluble inhibitory factor present in plasma. The only additional effect of concurrent infection by HIV with Myco. tuberculosis was decreased IL-6 secretion following ex vivo stimulation of leucocytes. Reduced proinflammatory cytokine release may represent a critical impairment of host immune defences important in determining outcome in tuberculosis.     

Liver Biopsy in HIV-Infected Patients with Chronic Hepatitis C: Pros and Cons

Abstract

Liver biopsy was a common procedure in patients with chronic hepatitis C who planned to begin treatment with interferon. The greater response rates seen with the use of dual combination therapy with interferon plus ribavirin and the almost universal recognition of fibrosis and faster progression to cirrhosis seen in HIV-HCV coinfected patients does not justify the request of a liver biopsy before prescribing anti-HCV therapy in this population, outside clinical trials.