Role of hepatic enzymes in the biochemical assessment of the severity of sickle cell anemia.

BACKGROUND AND OBJECTIVES: Various clinical and hematological indices have been used to assess the severity of Sickle Cell Anemia (SCA), however biochemical indices are lacking. Hepatomegaly has been a frequent finding in SCA and its persistence has been associated with increased disease severity. The association between hepatic enzymes and disease severity in SCA is undefined. This study was therefore designed to look at the association between clinical severity and hepatic enzymes in SCA subjects with persistent hepatomegaly (that is, lasting more than six months) in order to determine a possible role for hepatic enzymes as a biochemical index of severity.

MATERIALS AND METHODS: Serum levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (SAP) and gamma-glutamyl-transferase (GGT) were determined in two groups of SCA subjects and in hemoglobin genotype AA (HbAA) controls. SCA group comprised of 37 subjects with persistent hepatomegaly equal to or greater than 10 cm (below right coastal margin) while the second group comprised another 38 SCA subjects without palpable hepatomegaly. 40 individuals with hemoglobin genotype AA served as control for both groups. Clinical and hematological parameters of severity which included steady state haematocrit, number of transfusions per year, number of crises per year and percentage HbF level were determined and scored in a manner similar to the Glasgow coma scale. Results obtained were analyzed with the aid of statistical package on EPI-INFO version 6.02.

RESULTS: There was a significant increase in serum ALT, ALP and GGT levels in SCA with persistent hepatomegaly over those without hepatomegaly (p < 0.05, p < 0.05 and p < 0.01 respectively). All the index scores and the final aggregate severity scores were also significantly higher in SCA subjects with persistent hepatomegaly. Only GGT demonstrated a fairly positive and significant correlation (r = 0.46, P < 0.05) with increased clinical severity among the hepatic enzymes.

CONCLUSION: Elevated serum level of GGT in SCA during steady state is suggestive of increased disease severity.