Opportunistic infections in HIV-infected individuals: hepatitis C virus

Risk factors for hepatitis C on the Texas-Mexico border

OBJECTIVES

Our clinical experience suggested that hepatitis C virus (HCV) infection in this Texas-Mexico border area might have features, especially risk factors, that differ from some other areas of the United States. Therefore, we conducted a prospective analysis to investigate the epidemiology, risk factors, and certain other characteristics of HCV infection in the El Paso region.

METHODS

During a 2-yr period, individuals with a positive HCV serology were considered as "patients" and those with a negative hepatitis serology panel were "controls." A questionnaire survey was conducted in person or by telephone with individuals (patients and controls) who agreed to participate in the interview process.

RESULTS

We identified and interviewed 320 patients and 307 controls. All of the contacted patients and controls agreed to be interviewed. Many established and potential risk factors for HCV transmission were documented in the patients. Furthermore, multiple potential risk factors were often present in individual patients. However, on multivariate analysis only injection drug use, blood transfusion, and tattooing were found to be significant independent risk factors for HCV infection. In the great majority of patients, tattoos were applied by friends (including gang members), inmates in jail/prison, or self, rather than commercial parlors.

CONCLUSIONS

Tattooing is an independent risk factor for HCV infection in this United States-Mexico border area. The role of nonsterile tattooing practices in HCV transmission merits additional examination in regard to precise risk settings, frequency, and mechanisms of infection.

Three broad modalities in the natural history of vertically acquired hepatitis C virus infection

BACKGROUND

Little is known about the natural history of vertically acquired hepatitis C virus (HCV) infection.

METHODS

We performed a large, multicenter, prospective study of children born to HCV-infected women in Europe. Children were considered to be infected on the basis of > or = 2 polymerase chain reaction (PCR) test results positive for HCV RNA and/or test results positive for anti-HCV antibody > 18 months after birth.

RESULTS

Two hundred sixty-six children with vertical HCV infection were followed up until a median of 4.2 years of age (range, 3.2 months to 15.9 years of age). Twenty-six children were coinfected with human immunodeficiency virus. Hepatomegaly, the only clinical sign reported, was found in 10% of children and was significantly associated with a high proportion of abnormal alanine transaminase (ALT) levels (adjusted odds ratio [OR], 4.17; 95% confidence interval [CI], 1.67-10.42; P = .002). An estimated 21%-25% of children may have cleared the virus (i.e., had 2 consecutive PCR test results negative for HCV RNA, normal ALT levels, and no clinical signs) at a median age of 14.9 months. A high proportion of positive PCR test results obtained in the first year of life was associated with a lower likelihood of clearance (OR, 9.77; 95% CI, 2.92-32.67; P < .0001) and persistent viremia in children > 1 year old (adjusted OR, 2.92; 95% CI, 1.09-7.80; P = .03).

CONCLUSIONS

We confirm the low prevalence of HCV-related clinical signs and symptoms among vertically infected children in the first 10-15 years of life. Approximately 20% of children appear to clear the infection, 50% have evidence of chronic asymptomatic infection, and 30% have evidence of chronic active infection. Although viremia and abnormal ALT levels were associated with hepatomegaly, further investigation is necessary before these markers can be used in the clinical management of HCV infection in children.

Intrahepatic CD4+ Cell Depletion in Hepatitis C Virus/HIV???Coinfected Patients

Coinfection with HIV and hepatitis C virus (HCV)-specific immune responses, increases hepatic inflammation, accelerates hepatic fibrosis, and is associated with deceased treatment responses. We quantified intrahepatic lymphocyte and hepatocyte phenotypes in HCV-infected patients with (n = 38) and without (n = 41) HIV infection. A single pathologist counted positive cells in 5 portal and 5 lobular areas. Coinfected patients had 6.81 +/- 1.9 fewer CD4 cells per portal field (10.58 +/- 1.12 vs. 4.97 +/- 1.09 cells/high-power field [HPF]; P < 0.001) and 0.48 +/- 0.15 more apoptotic lymphocytes per lobular field (0.16 +/- 0.06 vs. 0.64 +/- 0.15 cell/HPF; P = 0.002) than monoinfected patients. The number of portal CD4 cells was not associated with the peripheral CD4 cell number. Portal and lobular CD8 cells did not differ between the 2 groups. Portal proliferative hepatocytes were increased in coinfected patients with HIV RNA levels of >400 copies/mL (1.13 +/- 0.32 cells/HPF; P = 0.01) compared with those with undetectable HIV RNA (0.46 +/- 0.09 cell/HPF) and monoinfected patients (0.45 +/- 0.08 cell/HPF). In conclusion, HIV coinfection is associated with fewer portal CD4 cells and increased lobular lymphocyte apoptosis that may impact on the natural history of HCV infection.

Hepatitis B and C virus infections in the immune compromised

PURPOSE OF REVIEW

This review compares and contrasts the natural history and treatment of hepatitis B and C virus infections in three principal populations of immune compromised individuals: (1) patients co-infected with HIV; (2) patients with liver failure secondary to hepatitis B or C virus infection who undergo liver transplantation, and (3) patients with hepatitis B or C virus infection who undergo anticancer chemotherapy.

RECENT FINDINGS

Chronic liver disease resulting from hepatitis B or C virus infection progresses more rapidly in patients co-infected with HIV than in HIV negative patients. Treatment protocols for antiviral therapy are, however, similar to those used in immunocompetent individuals and although few long-term results are available, the efficacy of interferon and ribavirin therapy in hepatitis C virus/HIV infection and lamivudine in HIV/hepatitis B virus infection has been proven in the short-term. Perhaps the most important consideration is the timing of administering treatments to co-infected patients. For patients with well preserved CD4 counts and hepatitis C virus/HIV co-infection, the hepatitis infection should be treated as early as possible to avoid drug interactions of hepatitis C virus antivirals with antiretroviral therapy. Also, response to hepatitis C virus treatment appears better when treatment is administered in the context of preserved immune function. Conversely, in hepatitis B virus/HIV co-infection, hepatitis B virus antivirals are best administered with anti-retroviral therapy, thus preventing the selection of HIV viral species which may be resistant to the drugs used for hepatitis B virus. Improved graft and patient survival after liver transplant and with anticancer chemotherapy in hepatitis B virus infected patients has been proven using lamivudine prophylaxis. However, although therapy for hepatitis C virus recurrence after liver transplantation would seem rational, limited success with current treatment protocols has been achieved.

SUMMARY

Although the prognosis of hepatitis B and C virus infections in the immune compromised may be inferior to that of immunocompetent individuals, such patients should have full evaluation of their viral hepatitis, and antiviral therapy should be considered.