Abstract
The erythropoietin response to anaemia was compared in 30 children with haemolytic anaemia and in 5 children with Fanconi’s hypoproliferative anaemia. Serum erythropoietin was measured by radioim-munoassay. In children with haemolytic anaemia the serum erythropoietin concentration increased exponentially with decreasing haematocrit values (r = -0.74; p < 0.001). Serum erythropoietin levels also correlated with reticulocyte counts (r = 0.62; p < 0.001). Children with Fanconi’s hypoproliferative anaemia had considerably higher serum erythropoietin levels than children with haemolysis for the same degree of anaemia. These data indicate that erythropoietin production in Fanconi’s anaemia may be dependent on other factors in addition to the degree of anaemia and relative hypoxaemia