May hepatic granulomas be part of the histological spectrum of chronic hepatitis C?

While older large series of patients with hepatic granulomas have found sarcoidosis and tuberculosis to be the most common causes of hepatic granulomas, recent works have noted some patients with chronic hepatic C and hepatic granulomas and no other obvious associations.

Today, patients that undergo liver biopsy often have chronic hepatitis C that is being staged prior to possible anti viral therapy. The age of HIV and immunosuppression for organ transplants has also made opportunistic infections associated with hepatic granulomas more likely.

A research article to be published on November 7, 2008 in the World Journal of Gastroenterology addresses this question. The research team led by Ned Snyder from the University of Texas medical branch report a retrospective study of over 4 000 liver biopsies as well as a prospective study of 240 patients with chronic hepatitis C undergoing routine liver biopsies. They found that the most common association for hepatic granulomas was chronic hepatitis C. In the prospective study of patients with stable hepatitis C, almost 1% had hepatic granulomas.

In this paper, no reason for the association between granulomas and hepatitis C was found unless granuloma formation is part of the immune response to chronic hepatitis C. Hepatic granulomas have been associated with interferon therapy for hepatitis C and other disorders, but only one patient in the study had received interferon. Granulomas sometimes can develop in intravenous drug users from talc in the injection solution, but examination of the biopsies with polarized light revealed only one patient with crystalloid particles.

The authors concluded that granulomas are an uncommon part of the histologic spectrum of chronic hepatitis C. When granulomas are found in the liver of a patient with chronic hepatitis C, the clinician should be comfortable with the association after other pertinent diseases are excluded.

A reviewer felt this paper is a very good retrospective examination of characteristics associated with hepatogranulomas, with the added strength of the prospective surveillance.