By Liz Highleyman

A growing body of evidence indicates that HIV positive people coinfected with chronic hepatitis C virus (HCV) infection tend to experience more rapid liver disease progression, although not all studies have seen this effect, especially among individuals who are taking highly active antiretroviral therapy (HAART) and have relatively high CD4 cell counts.

The stream of conflicting data continued at the Digestive Disease Week (DDW 2009) annual meeting last week in Chicago, with one study finding no difference in fibrosis progression between HCV monoinfected and HIV-HCV coinfected people, while another showed worse clinical outcomes in coinfected patients.

Fibrosis Progression

In the first study, Frank Grünhage and colleagues from Germany sought to analyze the effects of HAART on liver fibrosis progression as assessed by transient elastography (FibroScan). They performed a cross-sectional comparison between 84 HCV monoinfected and 57 HIV-HCV coinfected patients presenting at their outpatient clinic.

Overall, the investigators stated, they "did not find any difference in the distribution of liver stiffness" between HCV monoinfected and HIV-HCV coinfected patients (14.4 vs 12.4 kPa). However, 8 HIV patients with CD4 counts < 200 cells/mm3 had markedly greater liver stiffness than HIV positive individuals with well preserved immune function (18.4 vs 11.5 kPa).

These findings, they researchers, "confirm an improved prognosis of chronic hepatitis C in HIV positive patients under effective HAART," and "may be a hint" that fibrosis progression in well-treated HIV positive patients may no longer be different from that of HCV monoinfected patients.

Medical Department I, Saarland University Hospital, Homburg, Germany; Department of Internal Medicine I, University Hospital Bonn, Bonn, Germany; Institute for Experimental Hemostasiology and Transfusion Medicine, University Hospital Bonn, Bonn, Germany.

Clinical Outcomes

In the second study, Ashwin Ananthakrishnan and colleagues assessed the impact of HIV-HCV coinfection in a nationally representative cohort of hospitalized patients. Using data from the 2006 Nationwide Inpatient Sample -- a national database of hospitalizations from a stratified sample of U.S. community hospitals -- the researchers identified discharges of patients with HCV, HIV or HIV-HCV coinfection through corresponding ICD-9 codes.

In total, the study included 474,843 discharges with HCV alone, 206,758 with HIV alone, and 56,304 with HIV-HCV coinfection. Coinfected patients were younger on average, more likely to be non-white, and more likely to be on Medicaid than those with HCV alone; the coinfected patients, however, had a lower comorbidity burden compared to those with HCV alone.

The primary outcomes of interest were in-hospital mortality, length of stay, and hospitalization charges. Multivariate regression analysis was performed to determine whether HIV-HCV coinfection was associated with adverse outcomes.

Results

Liver-related admissions were more common among HIV-HCV coinfected patients compared to those with HIV alone (15.4% vs 3.3%).

However, hospitalization with a primary discharge diagnosis of any infection other than HIV or HCV was more common among HIV monoinfected patients compared with coinfected patients.

HIV-HCV coinfection was associated with significantly higher mortality rate compared with HCV infection alone (odds ratio [OR] 1.41).

While HCV infection by itself did not influence mortality in patients with HIV, HCV-associated liver cirrhosis or its complications conferred a nearly 4-fold greater risk of death on people with HIV (OR 3.96).

Taking into account national prevalence estimates for HIV, hepatitis C, and coinfection, the rate of hospitalization for HIV-HCV coinfected patients (23.5%) was significantly higher than that of patients with either HCV or HIV alone (14.8% and 19.9%, respectively).

Based of these findings, the study authors concluded, "HCV-HIV coinfection is associated with significantly higher rates of hospitalization and is a risk factor for in-hospital mortality compared to patients with isolated Hepatitis C or HIV infection."

Division of Gastroenterology and Hepatology, Division of Epidemiology, and Division of Infectious Diseases, Medical College of Wisconsin, Milwaukee, WI.

6/9/09

References

F Grünhage, JC Wasmuth, N Vidovic, and others. Transient Elastography Discloses Identical Distribution of Liver Fibrosis in Chronic Hepatitis C Between HIV-Negative and HIV-Positive Patients on HAART. Digestive Disease Week (DDW 2009). Chicago. May 30-June 4, 2009. Abstract M1713.

AN Ananthakrishnan, EL McGinley, J Fangman, and K Saeian. Hepatitis C-HIV Co-Infection Is a Risk Factor for Worse Outcomes in Hospitalized Patients: a National Study. Digestive Disease Week (DDW 2009). Chicago. May 30-June 4, 2009. Abstract M1765.