Background: Infection by hepatitis B virus (HBV) causes complicated biochemical, immunological and histological changes in host immune response against the virus which can be specific or nonspecific. Recent attention has focused on neopterin as a marker for the activation of cell mediated immunity. The aim of this study was to define the pattern of neopterin levels in replicative and nonreplicative HBV carriers. Methods: Thirty HBV replicative carriers and 25 nonreplicative HBV carriers and 30 healthy adult patients were included this study. Hepatitis markers were determined by commercial kit based on chemilumminesans assay. HBV DNA was quantified by hybrid capture system. Serum neopterin levels were measured by the method of competitive enzyme-linked immunosorbent assay. Results were expressed as mean +/- SD and ranges. Results: In the nonreplicative group, except for one patient, all the patients' HBeAg were negative and anti-HBe were positive. That particular patient was HBeAg positive and anti-HBe negative. In the replicative group, 23 out of 30 patients have positive HBeAg and negative anti-HBe; 7 out of 30 patients have negative HBeAg and positive anti-HBe. Serum neopterin concentrations were 14.5 +/- 10.0 (4.2 - 41) nmol/L in replicative HBV carriers, 8.9 +/- 4.3 (2.1 - 22) nmol/L in nonreplicative HBV carriers and 7.1 +/- 2.2 ( 4.0 - 12) nmol/L in the control group. Serum neopterin levels and the rates of abnormal serum neopterin levels in the replicative group were higher than the control group ( P < 0.01 and P < 0.05). In the nonreplicative group, serum neopterin levels were not different from those of control. There was a difference between replicative and nonreplicative groups in the respect of neopterin levels. Conclusion: In the hepatitis B infected carriers, elevated neopterin levels may be an indicator of the presence of replication. C1 Pamukkale Univ Med Fac, Dept Microbiol, Denizli, Turkey. Pamukkale Univ Med Fac, Dept Gastroenterol, Denizli, Turkey. Pamukkale Univ Med Fac, Dept Biochem, Denizli, Turkey.
