Megan Brooks

April 04, 2013

Fluctuations in circulating hepatitis C virus RNA could be "clinically meaningful" in a substantial number of patients with chronic infection, and could influence the best time to prescribe antiviral therapy.

"Decisions based on early viral kinetics, such as early stopping rules, may require the testing of baseline specimens collected closest to treatment initiation," said researcher Vincent Soriano, MD, from Hospital Carlos III in Madrid, Spain.

He presented study results at the International Conference on Viral Hepatitis 2013 in New York City, which was sponsored by the International Association of Providers of AIDS Care and the Icahn School of Medicine at Mount Sinai.

Dr. Soriano and his team conducted a retrospective review of longitudinal plasma hepatitis C RNA determinations in 818 consecutive untreated patients with chronic virus seen at a clinic in Madrid. For comparison, the researchers used longitudinal plasma human immunodeficiency virus (HIV) RNA measurements from 333 untreated HIV patients followed at the same clinic.

They analyzed 3169 hepatitis C RNA values obtained over 66.2 months and 1998 HIV RNA values obtained over 27.3 months.

Overall, a variation in viral RNA greater than 0.5-log IU/mL occurred more often in hepatitis C specimens than in HIV specimens (44% vs 23%; < .001). The same was true for variations greater than 1.0-log IU/mL (15% vs 4%; < .001).

On multivariate analysis, predictors of viral variations greater than 0.5-log IU/mL were lower hepatitis C RNA levels (odds ratio [OR], 0.35; 95% confidence interval [CI], 0.26 - 0.47; = .001), HIV coinfection (OR, 2.57; 95% CI, 1.56 - 2.68; < .001), and IL28B-CC alleles (OR, 1.87; 95% CI, 1.28 - 2.74; = .001).

This study "confirms something that many people knew, that fluctuations in hepatitis C RNA levels are greater and more variable than those of HIV," conference cochair Douglas Dieterich, MD, from the Icahn School of Medicine at Mount Sinai, told Medscape Medical News.

"Using response-guided therapy [RGT] with the new direct-acting antivirals has become the standard of care, and the baseline level of hepatitis C RNA is a very important component of RGT," Dr. Dieterich added. "The timing of treatment to maximize hepatitis C RNA may be a new way to increase treatment success."

Dr. Soriano reports relationships with Boehringer Ingelheim Pharmaceuticals, Gilead Sciences, Janssen Pharmaceuticals, Merck & Co, and AbbVie. Dr. Dieterich reports relationships with Boehringer Ingelheim, Bristol-Myers Squibb, Gilead Sciences, Genentech, and Novartis Pharmaceuticals.

International Conference on Viral Hepatitis (ICVH) 2013: Oral Abstract 10. Presented March 25, 2013.