NEW YORK (Reuters Health) – A low platelet count in the presence of hepatitis C viremia indicates the need to begin interferon-based treatment, regardless of the degree of liver fibrosis, a Taiwanese research team advises based on a new study.

Between 2002 and 2005, Drs. Wan-Long Chuang and Dr. Ming-Lung Yu and colleagues at Kaohsiung Medical University Hospital surveyed various clinical indicators in residents of the Kaohsiung area in southern Taiwan (n = 11,239; ages 40-65 years). Their findings appeared online in the Journal of Hepatology on December 3.

The researchers defined low platelet count as less than 150,000 platelets/microliter, and determined fibrosis noninvasively using the FT score (FibroTest, Biopredictive, Paris, France), which is based on five serum biochemical markers.

The prevalence of anti-HCV antibodies was 6.3%. Prevalence rates for abnormal alanine aminotransferase (ALT) and low platelet count were 20.3% and 4.2%, respectively. Among a subset of 642 individuals positive for anti-HCV antibodies, 74.5% tested positive for HCV RNA.

On multivariate analysis, low platelet counts in patients with anti-HCV antibodies were linked with abnormal ALT levels (OR 3.70) and positive HCV RNA (OR 2.00). The authors also report that in anti-HCV antibody-positive patients, a low platelet count predicted HCV viremia with 88% sensitivity.

“The presence of HCV RNA plays an essential role in disease progression,” the authors note, adding that the association of low platelet count with viremia “should help clinicians identify patients with active HCV infection for further intervention.”

The add, “No matter if the ALT levels are normal or elevated, the platelet counts are a good predictor for positive HCV RNA in clinical applications.”

Further studies to explain the underlying biologic mechanisms of their findings “are mandatory,” the researchers conclude.

J Hepatol 2009.