Hepatitis B and C infections in multitransfused thalassemic patients.

Abstract

Transfusion transmitted infections (TTI) are major causes of morbidity and mortality among multi-transfused patients such as thalassemics, hemophilics, patients on hemodialysis etc. Article by Sabat et al. in this issue of the Journal is of great concern for developing countries, including India where the prevalence of antibodies to hepatitis C, HBsAg, anti HBs and anti HBc was observed in 3.4, 0.5, 30.4 and 21.8% of 174 thalassemic cases respectively [1]. Higher prevalence with increasing age and blood transfusion is well understood. However, the major concern is of occult hepatitis B infection (OHBV) in 50% cases with positive anti HBc. Higher incidence of OHBV has been reported earlier [2, 3]. Presence of OHBV in patients with liver cirrhosis is still higher [4, 5]. Presence of HBV DNA in over 16% anti HBs and anti HBc positive patients is indicative of continued viral replication, which may consequently lead to development of liver cirrhosis or hepatocellular carcinoma [1]. Sabat and her colleagues [1] have included the prevalence of HBV and hepatitis C viral markers after 2002 while an earlier review by Choudhry and Acharya had clearly shown that the evidence of active and past evidence of HBV infection varied in 60–80% of cases, HCV varied in 15–60% and hepatitis D in upto 16% [6]. Higher prevalence of HBV and HCV infection earlier may be because the blood screening was being done by ELISA first generation kits for hepatitis B and no screening tests were being undertaken for hepatitis C. In a review of 40 studies involving 8554 thalassemic patients from eastern Mediterranean countries HCV seroprevelance was observed in 18, 45, 63 and 69% of cases in Iran, Pakisthan, Saudi Arabia and Egypt respectively [7]. Among Iranian thalassemic patients, splenectomy, higher number of transfusions, increasing age and first transfusion before 1996 were major risk factors for HCV infection. Higher prevalence of HCV is of relevance as presence of co-infection with HBV is likely to increase the risk of development of cirrhosis and hepatocellular carcinoma by manifolds. Higher prevalence of HCV infection earlier is well understood as blood donors were not being screened for HCV before 1996 in many countries. Patients with thalassemia are not only at higher risk for transfusion transmitted infections (TTI) but are also at higher risk for gram positive, gram negative and tubercular infection. Splenectomy further increases the risk of infection [8]. A multicentric study from Italy revealed that infections are the second most common cause of complication after cardiac mortality [9]. Similar data has been observed in studies from Taiwan and Greece [10, 11]. Higher prevalence of various infections are secondary to immune system dysfunctions, which needs to be investigated in well planned studies for better elucidation. However various reviews have shown the following important immune dysfunctions [12–14]: