Managing symptomatic drug-induced liver injury in HIV-hepatitis C virus-coinfected patients: a role for interferon.

BACKGROUND: Human immunodeficiency virus (HIV)-infected patients with hepatitis C virus (HCV) coinfection are at increased risk for drug-induced liver injury (DILI) compared with patients with HIV infection alone. The mechanism underlying this observation is unknown. We hypothesized that interferon (IFN) would induce biochemical improvement through its anti-inflammatory properties and thereby facilitate the reintroduction of antiretroviral therapy (ART) in patients with DILI. METHODS: Patients with symptomatic DILI were referred for evaluation; biopsy of a liver sample was performed for all patients, except 1 with clinical cirrhosis. RESULTS: Twelve patients with acquired immunodeficiency syndrome and symptomatic grade 3/4 hepatotoxicity received treatment with IFN and ribavirin (RBV). Seven of these patients had a history of recurrent DILI. The mean baseline CD4(+) T cell counts and HIV RNA levels were 124 cells/mm(3) and 115,369 copies/mL, respectively. Biopsies of liver samples demonstrated significant necroinflammation (mean grade, 10.3) and fibrosis (mean stage, 2.9). Three patients continued to receive ART when they began treatment with IFN-RBV; 9 reinitiated ART within an average of 12 weeks (range, 4-20 weeks) of HCV treatment initiation. All patients attained marked improvement in aminotransferases and continued to receive ART treatment during a mean follow-up regimen of 26.5 months, with subsequent virologic suppression and immunologic reconstitution (mean CD4(+) cell count increase, 251/mm(3)). However, only 1 patient maintained HCV suppression after completion of treatment with IFN-RBV. CONCLUSIONS: In patients with symptomatic DILI, treatment with IFN-ribavirin (RBV) led to decreases in aminotransferase levels, which enabled the reinitiation of ART. The beneficial effects of IFN-based therapy may be modulated through the suppression of proinflammatory cytokines, even in virologic nonresponders. Herein, we propose a novel mechanism for DILI, whereby HCV- and HIV-associated inflammatory mediators induce liver injury synergistically.

Low perforin and elevated SHIP-1 expression is associated with functional anergy of natural killer cells in chronic HIV-1 infection.

Natural killer (NK) cells are critical for the first-line defense in infection. Treated viremic HIV-1 infection is associated with the expansion of an anergic subset of CD3-CD56-CD16+ NK cells unable to respond to stimulation with MHC-devoid target cells or with mitogens. These CD3-CD56-CD16+ NK cells expressed SHIP-1 and had significantly reduced perforin levels. This observation suggests a mechanism for the reduced functional activity of CD3-CD56-CD16+ NK cells in chronic HIV-1 infection.

Acute hepatitis C virus infection in incarcerated injection drug users.

BACKGROUND: The Centers for Disease Control and Prevention has emphasized the need for interventional programs regarding hepatitis C virus (HCV) infection for injection drug users, the group of persons who are at highest risk of acquiring acute infection. METHODS: We designed a pilot study to assess the feasibility of identifying injection drug users with acute HCV infection in correctional and detoxification facilities. On-site medical providers were educated regarding risk factors and signs and symptoms of infection and were instructed to refer all patients with hepatitis to our specialty clinic. RESULTS: Over a 30-month period, 21 patients received a diagnosis of acute hepatitis C, 3 received a diagnosis of hepatitis B, and 1 received a diagnosis of hepatitis A. Of the 21 patients with acute hepatitis C, 19 were identified in the prison setting shortly after incarceration. Of the 17 patients who were observed serially (mean duration of observation, 6.3 months), 8 had spontaneous virologic clearance. Early therapy with pegylated interferon was initiated for 5 patients with persistent viremia and led to a sustained virologic response in 2 individuals. All patients agreed to undergo human immunodeficiency virus counseling and testing, as well as to receive immunization for hepatitis A and B. CONCLUSIONS: Incarceration presents a unique opportunity to identify injection drug users with acute HCV infection, to initiate counseling regarding other bloodborne pathogens, and to facilitate immunizations and HCV treatment.

Hepatic steatosis is associated with fibrosis, nucleoside analogue use, and hepatitis C virus genotype 3 infection in HIV-seropositive patients.

BACKGROUND: We conducted a study to determine the prevalence and factors associated with hepatic steatosis in human immunodeficiency virus (HIV)-seropositive patients with hepatitis C and to investigate whether steatosis is associated with liver fibrosis. METHODS: Retrospective chart reviews were conducted in 4 hospitals that serve community-based and incarcerated HIV-infected patients who had undergone a liver biopsy for evaluation of hepatitis C virus (HCV) infection during the period of 2000-2003. Demographic characteristics and medication and laboratory data were collected from the time of the biopsy. A pathologist blinded to all clinical data evaluated the specimens. The primary outcome was presence or absence of steatosis. RESULTS: Of 260 HIV-HCV-coinfected patients, 183 met inclusion criteria and had a biopsy specimen adequate for review. Steatosis was present in 69% of patients (graded as minimal in 31%, mild in 27%, moderate in 18%, and severe in 1%). Factors associated with steatosis included use of dideoxynucleoside analogues, such as didanosine and stavudine (odds ratio [OR], 4.63; 95% confidence interval [CI], 1.55-13.82). There was a trend toward presence of steatosis and use of other nucleoside analogues or infection with HCV genotype 3 (OR, 2.65 [95% CI, 0.95-7.41] and 3.38 [95% CI, 0.86-13.28], respectively). The presence of steatosis was associated with fibrosis (OR, 1.37; 95% CI, 1.03-1.81). CONCLUSIONS: In this multiracial population of HIV-HCV-coinfected patients, steatosis was prevalent and was associated with severity of liver fibrosis. Use of nucleoside analogues (particularly didanosine and stavudine) and HCV genotype 3 infection were associated with hepatic steatosis. The development of steatosis is multifactorial in nature and may play a contributory role in the progression of liver disease in HIV-infected patients.

Extensive HLA class I allele promiscuity among viral CTL epitopes.

Promiscuous binding of T helper epitopes to MHC class II molecules has been well established, but few examples of promiscuous class I-restricted epitopes exist. To address the extent of promiscuity of HLA class I peptides, responses to 242 well-defined viral epitopes were tested in 100 subjects regardless of the individuals' HLA type. Surprisingly, half of all detected responses were seen in the absence of the originally reported restricting HLA class I allele, and only 3% of epitopes were recognized exclusively in the presence of their original allele. Functional assays confirmed the frequent recognition of HLA class I-restricted T cell epitopes on several alternative alleles across HLA class I supertypes and encoded on different class I loci. These data have significant implications for the understanding of MHC class I-restricted antigen presentation and vaccine development.

Sequential deregulation of NK cell subset distribution and function starting in acute HIV-1 infection.

Natural killer (NK) cells are critical in the first-line defense against viral infections. Chronic HIV-1 infection leads to a perturbation in the NK cell compartment, yet the kinetics of this deregulation and the functional consequences are unclear. Here, we characterized changes in the NK cell compartment longitudinally by multiparameter flow cytometry, starting in acute HIV-1 infection. Acute HIV-1 infection was associated with elevated NK cell numbers, with an expansion of CD3(neg)CD56(dim)CD16(pos) NK cells and an early depletion of CD3(neg)CD56(bright)CD16(neg) NK cells. Ongoing viral replication resulted in a depletion of CD3(neg)CD56(dim)CD16(pos) NK cells with a paralleled increase in functionally anergic CD3(neg)CD56(neg)CD16(pos) NK cells, accompanied by reduced functional activity, as measured by CD107a expression and cytokine secretion. Taken together, these studies demonstrate a sequential impairment of NK cell function with persistent viral replication resulting from a progressive deregulation of NK cell subsets with distinct functional properties.