In cases where passive transfer of anti-HAV antibodies was suspected, the frozen aliquots of the donors plasma were not tested for the presence of anti-HAV antibodies. of anti-HAV IgG antibodies than normal populace of the same geographic area. This difference BI-78D3 is usually difficult to explain, but it can be attributed to the higher vulnerability of thalassemics to HAV contamination and to passive transfer of anti-HAV antibodies by blood transfusions. Keywords: Hepatitis A computer virus, Anti-HAV antibodies, Beta-thalassemia, Multiple transfusions, Hepatitis C computer virus INTRODUCTION Hepatitis A computer virus (HAV) hepatitis is usually spread by the fecal-oral route. Seroprevalence rates in BI-78D3 the USA, Western Europe and in several Mediterranean countries have been falling during the past few decades. In some countries no more than 10% of the adult populace has evidence of previous contamination[1]. In Greece, the lack of epidemics of HAV since early 1980s and the improvement of socioeconomic and hygienic conditions over the last decade seems to have contributed to the decline of the prevalence of anti-HAV antibodies[2,3]. Dalekos et al tested 1984 healthy individuals of Greek nationality for anti-HAV antibodies and found a prevalence of 39.8% in males and 33.2% in females[4]. According to the National Centre for Surveilance and Intervention of Greece, the median Tbp annual prevalence of acute hepatitis A in Greece for the time 1998-2003 was 1.88 cases/100 000 of population, which is comparable to the hepatitis A prevalence of the Western Europe[5]. Parenteral transmission is extremely rare, but can follow transfusion of blood from a donor who is in the incubation period of the disease[6,7]. The relatively short duration of viremia in acute hepatitis A, together with the moderate titer of HAV viral load in the blood[8], diminishes the likelihood of transfusing a unit of blood infectious for HAV. The potential cotransfusion of HAV-specific antibodies to the recipient of multiple blood units and the rising seroprevalence to HAV with age further diminish the risk of post-transfusion hepatitis A[9]. The aim of this study was to detect the prevalence of anti-HAV IgG antibodies in adult multitransfused beta-thalassemic patients and to compare this with the prevalence in healthy subjects of the same age and geographic area. MATERIALS AND METHODS Patients We studied 182 adult multi-transfused patients from West Peloponnese (88 males, 94 females, mean age 31.6 9.4 years, range 17-66 years) suffering from beta-thalassemia major (= 136) or intermedia (= 46). These patients were in follow up at the Thalassemia Center of the University Hospital of Patras. They were receiving regular transfusions of two models of packed red cells at about 3 BI-78D3 wk intervals in order to maintain the haemoglobin level above 10 g/dL. The mean age at first blood transfusion was 2 1.9 years, the mean duration of transfusion therapy was 26.6 8.5 years and the mean number of transfusions received up until the time of the present study was 931 482. Seventy-two patients (39.6%) had undergone splenectomy in the past. None of the patients had a history of intravenous drug use or chronic alcohol abuse. There were no reported cases of HAV hepatitis among the studied patients. In addition, none of the patients had received hepatitis A vaccination in the past. Serum used in the study was obtained just before a scheduled transfusion of packed red blood cells. The control group was made up of 209 normal subjects from West Peloponnese, matched for age and sex BI-78D3 (103 males, 106 females, mean age 31.2 8.5 years, range 17-58 years) from the volunteer blood donor program of our Hospital. Each.