Clinical significance of TT virus infection in patients with chronic hepatitis C

OBJECTIVE: The TT virus (TTV) is a novel DNA virus that has recently been i dentified. The clinical significance of TTV infection in patients with chro nic hepatitis C has not been determined. The aim of this study was to deter mine the prevalence and possible role of TTV in a well characterized popula tion with chronic hepatitis C infection. METHODS: Ninety patients with chronic HCV and known time of HCV acquisition were selected from approximately 250 patients followed at our institution. Characteristics including age, sex, histology, and length of disease were recorded. Direct sequencing of the NS5 region was used for HCV genotyping. TTV DNA detection was based on PCR. RESULTS: TTV infection was present in 24 of 90 (27%) HCV patients. Patients were divided into four groups based on stage of disease; chronic hepatitis (CH, 29 patients), compensated cirrhosis (CC, 17 patients), decompensated cirrhosis (DC, 28 patients), and hepatocellular carcinoma (HCC, 16 patients ). TTV was present in 2/29 (7%), 2/17 (12%), 11/28 (39%), and 9/16 (56%) in those with CAH, CC, DC, and HCC respectively. TTV was significantly more p revalent among those with advanced disease (DC and HCC) compared to those w ith stable disease (CH and CC; p = 0.001). Mean age, sex, and the time from exposure to HCV to development of complications were similar in TTV-positi ve and -negative patients. TTV infection was more common in patients infect ed with HCV genotype Ib. Univariate analysis showed that length of HCV infe ction, HCV genotype 1b, and TTV infection were important in predicting the stage of liver disease in HCV patients. However, after adjusting fur length of HCV infection, TTV but not HCV genotype was important in predicting the stage of Liver disease. CONCLUSIONS: We conclude that 1) TTV infection is common in patients with c hronic HCV; 2) TTV infection is more prevalent among patients with advanced HCV-associated liver disease DC and HCC) than in those with stable disease (CH and CC); and 3) TTV infection is more common in patients with HCV geno type 1b but is independent from genotype in predicting the stage of HCV-ass ociated liver disease. (C) 1999 by Am. Coll. of Gastroenterology.