RESUMO
Background: Lupus anticoagulant (LA) is a heterogeneous group of antibodies that causes a variety of clinical and laboratory effects; has been described in infections such as human immunodeficiency virus. LA has not been previously described in Nigerians with human immunodeficiency virus infection on highly active antiretroviral therapy (HAART). Aim: To determine the frequency of LA in patients infected with the human immunodeficiency virus on HAART. Methods: Cross sectional study of patients with human immunodeficiency virus infection undergoing HAART at a tertiary hospital in Nigeria. Screening for LA was done using the activated partial thromboplastin time (aPTT) and kaolin clotting time (KCT). Mixing experiments were conducted on samples with prolonged clotting time. KCT ratio was calculated. A positive result was taken as KCT ratio greater than or equal to 1.2. Fisher's exact test was used to test the association between LA and sex. Association between aPTT and KCT was tested according to Pearson. P-value < 0.05 was considered significant. Results: Fifty-eight patients aged 18- 60 years were studied, comprising of 28 males (mean age 40.50 plus/minus 8.8 years) and 30 females (mean age 35.4 plus/minus 9.02). Frequency of LA among human immunodeficiency infected patients was 5.2%, (frequency in males and females were 3.6 and 6.7 % respectively). This was lower than 46% reported in patients not on HAART. There was no statistically significant difference in LA prevalence between males and females P greater than0.05. A positive correlation was observed between the clotting tests aPTT and KCT (r is equal to 0.9406, p less than 0.0001). Conclusion: HAART may prevent development of LA in HIV-infected patients.
RESUMO
Background:The lupus anticoagulant (LA) is one of the antiphospholipid antibodies (aPL); which prolong phospholipid- dependent coagulation tests by interfering with coagulation reactions that depend on protein - phospholipid complexes in vitro. Method: A 25 year old 'healthy' male Nigerian was screened for the presence of any coagulation abnormality using the KCT; PT and platelet count; after volunteering for his plasma to be used in the preparation of normal pooled plasma in a study. Results: He was disco- vered to have a prolonged KCT; PT and normal platelet count. Based on the prolonged KCT his plasma was subjected to mixing studies with various concentration of normal pooled plasma; the KCT index was calculated and a curve was plotted. His KCT index was 1.6 and the curve convex in the left axis suggesting the presence of LA. His past medical history and physical examination were not remarkable.Three months after the initial study; a repeat KCT index was 1.4 and the subject asymptomatic. Conclusion: From literature review this is the first report of LA in an asymptomatic adult Nigerian; the importance of this finding is discussed