Lupus anticoagulant and leg ulcers in sickle cell anemia

The cause of chronic leg ulcer (CLU) in patients with sickle cell anemia (SCA) is unknown; it has been attributed to hypercoagulability associated with the disease. Recently, it has been suggested that a subset of SCA patients may be prone to developing CLU and that hemolysis may be an underlying factor in the development of CLU. The lupus anticoagulant (LA) is an antiphospholipid antibody (aPLa), these antibodies have been described in patients with SCA.

This study was designed to determine the frequency of LA in SCA patients with CLU compared with those without CLU.

Study design is a descriptive, cross-sectional one. Thirty-three SCA patients with CLU and 33 patients without CLU were screened for the presence of LA using the Kaolin clotting time (KCT), which is an important assay, and Kaolin clotting time index was calculated. Means were compared using the students' t test, proportions were compared using the chi-square test, level of significance was set at 0.05, odds ratio was calculated.

About 18.18% of patients with CLU had LA, compared with 6.06% among controls (P < 0.05); odds ratio was 3.44 (95% CI 0.64 - 18.51).

We conclude that SCA patients with CLU may be more likely to develop LA, and this may be related to the degree of hemolysis. Further studies are required to find out if CLU and LA are a result of hemolysis or if LA is responsible for the higher incidence of hemolysis and CLU found among these patients.