Alpha-hydroxybutyrate dehydrogenase and the diagnosis of painful crisis in sickle cell anaemia.

To assess the value of alpha-hydroxybutyrate dehydrogenase (alpha-HBDH) in the diagnosis of painful crisis (PC) of sickle cell anaemia (SCA), we studied plasma enzyme levels in 55 children with HbSS and 21 control subjects with haemoglobin genotype AA. In 21 children with SCA, mean plasma alpha-HBDH was 373.8 +/- 113.5 micrograms/l during PC and during steady state in 34 children, it was 341.2 +/- 103.4 micrograms/l. These values were significantly higher than that of 128 +/- 19.5 micrograms/l obtained in control subjects. However, the difference between mean plasma alpha-HBDH levels in SCA children in PC and in steady state was 32.6 micrograms/l, t = 1.095; P < 0.2. There was no correlation between alpha-HBDH levels and reticulocyte counts (r = 0.0856; t = 0.4565; 0.7 < P < 0.6). The high levels of alpha-HBDH in patients with SCA is probably due to chronic haemolysis and not marrow infarction. Therefore, alpha-HBDH is of doubtful value in the diagnosis of painful crisis.