Anti-phospholipid antibodies in systemic autoimmune diseases: a study among a sub-Saharan population

Introduction: Anti phospholipids antibodies (aPL) can be circulating during connectivitis without clinical manifestations. Their prevalence in the general caucasian population is low but can reach 55% in lupus and 57.5% in systemic scleroderma. In sub-Saharan Africa, the prevalence of these antibodies during systemic diseases is unknown. Earlier studies conducted have mainly focused on their clinical details linked to a connectivitis. Objective: To determine the frequency of aPL and their morbidities when associated with systemic autoimmune diseases among a Sub-Saharan population. Patients and methods: We conducted a cross-sectional multicenter study with prospective recruitment in Le Dantec Hospital Internal Medicine and Dermatology departments and also dermatology department of the Social Hygiene Institute of Dakar. All patients with a systemic autoimmune disease and who agreed to the informed consent form were included. Test Samples for aPL detection were conducted in the Hematology laboratory of Le Dantec Hospital. A 12-week interval control sample was performed for each patient who presented a positivity for one or more antibodies. The diagnosis of antiphospholipid syndrome (APS) was based on the Sydney classification criteria. Socio-demographic, clinical and paraclinical data were collected. Statistical analysis was performed using Epi-info 7.2 software. A p-value (less than) ≤ 0.05 was statistically significant. Results: Sixty patients with systemic autoimmune diseases were enrolled including 54 women (sex ratio=0.11). The mean age was 41.15 years. The aPL frequency was 60% (n=36) at the first blood test while the control test was positive at 33.3% (n=10). Lupus anticoagulant (LA) was positive in 35 patients corresponding to 58.3% and anticardiolipin (ACL) antibodies in 2 patients representing 3.3%. No β2-glycoprotein antibodies (aβ2-GP1) were detected. Five cases of APS were identified representing 8,4% of the sample. Five patients who didn’t meet the diagnosis criteria of APS (Sydney) were persistently aPL positive. Obstetric complications predominated with a statistical significance p=0.04. Cutaneous and digital ulcerations were not significantly correlated with APL (p=0.34 p=0.17). Headaches were observed in 78% of Apl positive cases without any statistical significance (p=0.298). A similar result was observed for Raynaud’s phenomenon (p=0.306). Conclusion: aPL are frequently positive during connectivitis but often transient. LA is the most common antibody and SLE is the main cause. Key words: connectivitis - antiphospholipid antibodies - antiphospholipid syndrome - sub-saharan africa.