[Influence of the hematocrit on the formation of Heinz bodies within the red cells (author's transl)].

The increased in vitro formation of Heinz bodies in erythrocytes exposed to oxidant agents (acetylphenylhydrazine) is an excellent screening test for the diagnosis of various congenital abnormalities of red blood cells (G-6-PD deficiency, unstable haemoglobins). This phenomenon is strongly dependent of the PCV of the test blood. Anemia by itself (hematocrit less than 30 p. cent) may be responsible for an increased formation of Heinz bodies even in the absence of any erythrocyte abnormality. This finding confirm that the results of the test are of value only if the PCV of blood samples is adjusted to 40 p. cent.