Influence of crisis on haemoglobin F level in adult Nigerian sickle cell anaemia patients.

Forty-six Nigerian adult sickle cell anaemia patients were investigated, each in sickle cell crisis and steady state. Forty-three patients had vaso-occlusive crisis while three had haemolytic episodes. Investigations included Packed Cell Volume (PVC), Reticulocyte count and Haemoglobin F estimation. PCV was carried out by the microhaematocrit method while the reticulocytes were counted manually. Haemoglobin F was estimated by the Alkali Denaturation Technique. There was significant anaemia (p < 0.05) and reticulocytosis (p < 0.0001) during the period of crisis compared to the steady state. There was no significant difference (p > 0.05) between HbF level in crisis and that in the steady state. In other words the previously documented increase in HbF during reticulocyte response did not take place in our model. Maybe a 'critical' level of reticulocytosis was not attained. It was also shown that vaso-occlusive crisis did not induce an increase in HbF level suggesting that HbF might be genetically determined at a constant low level throughout life in each of our patients.