| [ Summary ] |
In this study, we investigated whether an autoimmune mechanism is involved in thrombocytopenia, observed in patients with chronic hepatitis C. Platelet-associated IgG (PAIgG) and platelet-associated IgM (PAIgM) were measured by dircct immunofluorescent flow cytometric analysis. thirty seven patients with chronic hepatitis C, including twenty eight with chronic hepatitis and nine with cirrhosis, nineteen patients with chronic immune thrombocytopenic purpura (ITP) and thirty four healthy subjects were enrolled. PAIgM levels were elevated about 3.5-fold in chronic hepatitis C patients compared to healthy subjects. PAlgG levels were also elevated approximately 2-fold in chronic hepatitis C patients, compared to healthy subjects The elevation of PAlgM values in these patients was comparable to that in the patients with chronic ITP. However, no correlation was found between PAIgM and platelet counts or PAIgM and platelet counts. Eluted PAIgG and PAIgM reacted with normal platelets in none of the patients with chronic hepatitis C showing positive PAIgM value, indicating that eluted PAIgG and PAIgM contained no detectable anti-platelet antibodies. During alpha-interferon therapy, the levels of PAIgG and PAIgM increased in association with the decrease in platelet counts in 50% and 67% of the patients with chronic hepatitis C. However, eluted PAIgG and PAIgM never reacted at any day-point with platelets from normal donors.
PAIgG and PAIgM were elevated in patients with chronic hepatitis C, but contained no detectable anti-platelet autoantibodies. Also, thrombocytopenia in these patients during alpha-interferon therapy seems not to be due to anti-platelet autoantibodies. |