Transient increase of fetal haemoglobin in kala-azar

Haemoglobin F (HbF) levels were significantly increased in 40 children with kala-azar in comparison with controls (3.36 +/- 2.32 versus 0.90 +/- 1.8; P < 0.01). The HbF was heterogeneously distributed among the red blood cells. The glycine residue of peptides gamma CN3 were within the normal umbilical cord blood range, and the haemoglobin synthesis in vitro was balanced. After recovery from kala-azar the HbF fell within the normal range. These results suggest that increased production of HbF is associated with accelerated erythropoiesis due to temporary marrow stress.