Hemopoietic improvement following fetal liver infusion in aplastic anemia

41 (38 males, 3 females) patients with aplastic anemia received fetal liver infusion (FLI) from 74 abortuses with gestation periods of 8-32 (Median(M)-16) weeks and cell dose of 0.004-11.1 x 10(8) (M-2.3 x 10(8)) from September, 1976 until November, 1987. 35 persons received single FLI; those with recurrence or no response received two or more FLI. 8 received two; 7, three; 2, four; and 1, six FLI. There was a slow and incomplete autologous hematopoietic improvement in 40% and expected survival of 52% at 1 year, 45% at 2 yr, and 37% at 5 yr (Kaplan Meier estimate). There was rise in fetal hemoglobin (Hb), 0-15.7%, (M-3.5) among responders in 3-20 (M-6) months. Patients who survived for more than 12 months had, on average, a longer duration of disease (4 months or more), and higher granulocyte and platelet counts. Statistically, however, these differences were not significant. Reticulocyte count was significantly lower in those who survived beyond 12 months. 1 patient developed acute undifferentiated leukemia 3 yr post-FLI. The study indicates that fetal liver infusion is likely to benefit about 40% of individuals suffering from severe aplastic anemia. Longer surviving patients, however, may be at risk of developing clonal diseases.