Plasma levels of some coagulation parameters in steady state HBSC disease patients

Sickle cell disease is a collection of autosomal recessive genetic disorders. It includes homozygous HbSS and double heterozygote combinations such as HbSC. Central and West Africa bears a significant burden of HbSC disease.

Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen concentration (FC) and platelet count (PC) were determined in 41 HbSC and HbSS patients in steady state along with 40 apparently healthy HbAA controls. One way ANOVA test was used to compare means; p values< 0.05 were considered statistically significant.

There was no significant difference in mean PT for the study groups (p = 0.192). Mean PC was highest in HbSS patients: 445.7 +/- 128.3 X 10 9/ L compared to HbSC: 330.0 +/- 97.7 X 10 9/ L and HbAA:245 +/- 77.7 X 10 9/ L (p = 0.000). Mean APTT was 28.1 +/- 3.8 seconds in controls,24.1 + /- 66 seconds in HbSS patients and 21.8 +/- 3.8 seconds in HbSC patients (p = 0.000). Mean FC in HbSS was 1.6 +/- 0.7 g/L, 3.2 +/- 0.6 g/L in HbSC and 2.9 +/- 0.4 g/L in HbAA (p = 0.000).

A significant difference exists in PC, APTT and FC in HbSC patients compared to HbSS patients and HbAA controls. Elevated FC and shortened APTT may play a role in complications more characteristic of HbSC such as retinopathy and osteonecrosis. These suggest HbSC is not merely a milder form of HbSS; both diseases should be seen as different entities with regards to approaches for management.