Hepatitis - Associated Aplastic Anaemia: Epidemiology and Treatment Results Obtained in Europe. A Report of the EBMT Aplastic Anemia Working Party.

Background. Most cases of acquired severe aplastic anaemia (SAA) are not associated with any other disease and are therefore classified as idiopathic. Hepatitis-associated aplastic anaemia (HAA) has been well described as a separate entity amongst the acquired aplastic anaemias. Aim of this study was to describe the epidemiology of HAA and to analyze treatment results obtained in Europe in the last 15 years.

Patients and methods. We evaluated 198 HAA out of 3684 AA patients reported to the SAAWP Registry between 1990 and 2005. Median age at diagnosis was 15 years (range 1–87) .132 were male and 66 female. Year, month and season of diagnosis were analyzed, as well as all variable related to the type and outcome of first line therapy.

Results.Prevalence of HAA amongst all acquired AA registered in Europe from 1990 to 2005 was 5.4% (198/3684).The majority of patients were male (66%), and median age was 15 years. The virus causing the hepatitis was unknown in most cases (94.5%) while only 11 / 198 (5.5%) were related to Hepatitis B or A virus infection. No significant differences were found in the prevalence according to the year, month or season of diagnosis. No geographic clusters could be identified. Seventy three HAA patients were treated with immunosuppression (IS) and 125 underwent Stem cell Transplantation (SCT): these were compared with 1539 and 2045 non-HAA patients given IS or SCT. The median age was significantly younger in the HAA as compared to the non-HAA patients (15 versus 20, p<0.0001). The median interval between diagnosis and treatment in IS and SCT was 8 and 67 days respectively. Median follow-up for surviving or deceased patients was 1356 and 155 days respectively. The actuarial survival at 10 years after IS was 66% for HAA and 52% for non-HAA (p=0.4). HLA identical sibling SCT produced survival of 83% in HAA and 74% in non-HAA patients (p=0.1); when the donor was unrelated, survival was respectively 63% and 52% (p=0.5). After stratification for stem cell source, actuarial survival was 83% vs 72% (p=0.06) for bone marrow, and 68% vs 57% (p=0.5) for peripheral blood.

Conclusions. The incidence of HAA in Europe is currently 5.4%, comparable with published data, and seems to be distributed homogeneously over the years, months and geographic areas. Results after IS or SCT in HAA patients are comparable to those obtained in idiopatic acquired non-HAA, treated in the same period in Europe. Therefore, HAA should be managed according to current guidelines for idiopathic aplastic anemia.