[Requirements of diagnostic criteria for aplastic anemia in children]

As a general rule, diagnostic criteria of aplastic anemia in children are the same as adult criteria. However, blood counts of normal children show wide age-related variation, therefore we must establish a system of adjustment for diagnosis of aplastic anemia in children. The data of children with aplastic anemia visiting our institutes from 1966 to 1990 were evaluated for this study. RBC below 350 x 10(4)/microliters, WBC below 4,000/microliters or neutrophils below 1,500/microliters, platelets below 8 x 10(4)/microliters, reticulocytes below 4 x 10(4)/microliters and lymphocytes over 60% were seemed to satisfy the diagnostic criteria of aplastic anemia proposed by the Study Group of hemopoietic Disorders sponsored by the Ministry of Health and Welfare of Japan. Fifteen children (4.6%) did not meet these criteria and as such were diagnosed as atypical aplastic anemia. Thirteen of them were in a pre-aplastic state and developed typical aplastic anemia within 6 months to 8 years after the initial diagnosis. Clinical findings of these patients showed the decrease in number of megakaryocytes and committed stem cells in bone marrow. Three of these patients developed acute non-lymphocytic leukemia, and 2 of them were diagnosed as Fanconi's anemias.