Red cell glucose-6-phosphate dehydrogenase status and pyruvate kinase activity in a Nigerian population

Glucose-6-phosphate dehydrogenase A(-) (G6PD A(-)) deficiency is a common enzymopathy in Africa that sporadically leads to manifest haemolytic anaemia. It is not exactly known how far the haematological status of individuals with either homozygous or heterozygous G6PD A- deficiency differs from that of individuals with normal G6PD activity. In a field study in Nigeria, we determined G6PD gene variants, the corresponding G6PD and pyruvate kinase (PK) activities, and basic haematological parameters in clinically healthy individuals, who were, in part, asymptomatically infected by malaria parasites. Red blood cell counts and haemoglobin levels were lower in G6PD A(-) deficient than in G6PD normal subjects. PK activities were higher in G6PD deficients, indicating a younger red cell population in these individuals. These findings suggest that G6PD A(-) deficiency is accompanied by chronic subclinical haemolysis. As a consequence, the reduced life span of red cells leads to an impaired diagnosis of G6PD heterozygosity when applying routine biochemical methods.