Clinical

Early immune response plays key role in hepatitis C clearance

Last Updated: 2004-10-28 9:55:12 -0400 (Reuters Health)

NEW YORK (Reuters Health) - A negative hepatitis C virus (HCV) RNA test and a broad cell-mediated immune response during the first month of infection are good predictors of viral clearance, according to a report in the November issue of Gut.

"Understanding the virus host interactions, which enable a proportion of patients with acute infection to clear HCV, is probably a key to the development of more effective treatment and prevention strategies," the authors explain.

Dr. E. Spada from National Center of Epidemiology, Rome, and colleagues in the Acute Hepatitis C Italian Study Group followed the clinical course of 34 consecutive patients with acute hepatitis C.

Nine of 10 patients with a self-limiting infection had a negative HCV RNA test within the first month of symptom onset, the authors report, compared with 4 of 24 patients who developed chronic HCV infection (p < 0.01).

A greater proportion of women (5/7) than men (5/27) experienced a self-limiting course, the report indicates, and patients who achieved a normal ALT level early and a higher median peak bilirubin level were more likely to have a self-limiting course of the disease. After adjusting for "age, sex, ALT and bilirubin levels at the onset, the only independent factor associated to a self self-limiting course of acute hepatitis C was female sex," the investigators report.

Strong T cell responses to multiple HCV antigens during the early phase of acute HCV infection was also associated with resolution of the infection, the researchers note (p < 0.01).

HLA class II type was not significantly associated with HCV outcomes, the results indicate, but HLA-DRB1*1101 was more frequent in resolving patients and was the allele detected in two women with the strongest and broadest T cell response.

"These findings suggest that repeated evaluation of HCV RNA status until the third month from the onset of disease can serve as a good predictor of the outcome of the infection and can be used as a useful criterion to decide the beginning of antiviral treatment," the investigators write.

"By implementing a T cell assay together with RNA detection tests within the first month from the onset of symptoms," the authors conclude, "one could select with high diagnostic sensitivity a group of patients with high probability to resolve the infection, preventing them having to undergo an early antiviral treatment."

"If such a combined test failed in predicting a favorable course," the researchers add, "treatment could still achieve high frequency of sustained virological response if started within the first 6 months from disease onset."

Gut 2004;53:1673-1681.