ABSTRACT
To analyze patients suffering from aplastic anemia [AA, peripheral pancytopenia and hypocellular bone marrow in the absence of dysplasia, infiltration and fibrosis] for documenting patient's baseline characteristics and association with various human leucocyte antigens. An observational, cross-sectional study. The National Institute of Blood Disease [NIBD], Karachi, from March 2003 to August 2008. All consecutive patients with confirmed diagnosis of AA were evaluated. Data included the baseline characteristics, complete blood counts [CBC], bone marrow biopsy findings, severity of disease, exposure to drugs or chemicals, viral serology and their HLA expression. The data was analyzed on SPSS programme and frequencies were documented. Among 318 patients, there were 236 [74.21%] males and 82 [25.78%] females. Median age was 16 and 70% belonged to urban population. Drug exposure could be established in 23 [7.23%] of cases, while 4 [1.25%] were HBV surface antigen positive and 7 [2.2%] were HCV antibodies positive. In all, 73 [22.9%] had very severe AA, 195 [61.32%] had severe AA while 50 [15.7%] cases had non-severe AA. HLA B5 [52] showed high expression in 83 patients [26%] in comparison to 5.9% reported in healthy population. AA was found to affect young adult males living in urban areas. HLA B5 [52] showed higher expression in patients with aplastic anemia