Prevalence of Antiphospholipid Antibodies in Sample of Iraqi Patients with Systemic Lupus Erythematosus: A Cross Sectional Study

Abstract

Objective: Antiphospholipid antibodies (APLAs) have high risk of vascularthrombosis with significant clinical comorbidities. Anticardiolipin antibodies (ACLAs)and Lupus anticoagulant (LA) are important APLAs. The aim of this study was to evaluate the prevalence of APLAs(ACLAs and LA) and their clinical significance among sample of Iraqi patients with systemic lupus erythematosus patients (SLE). Patients and methods: A single center cross sectional study conducted on 50 SLE patients diagnosed according to the 1997 revised American College of Rheumatology (ACR) criteria for SLE from February 2010 to April 2011. Patients' age at SLE diagnosis, disease duration, SLE disease activity index (SLEDAI), renal involvement, cerebral involvement, cardiac involvement, pregnancy events, and thrombotic events were analyzed. Serum samples were extracted and screened for IgG and IgM using an anticardiolipin (ACL) enzyme-linked immunosorbent assay, Lupus anticoagulant (LA), prothrombin time (PT), partial thromboplastic time (PTT), kaolin clotting time (KCT), and KCT index were assessed in all patients. Results: Of 50 SLE patients, the prevalence of positive anticardiolipin antibodies (ACLA) was 10(20%) and positive LA 5 (10%). Abnormal KCT12 (24.5%), Abnormal KCT index 5(10), Abnormal PTT2 (4.1%), and Abnormal PT 2(4%). Thrombotic events, pregnancy events, and cerebral involvement were associated with positive serology (P = 0.000, 0.225, 0.083 respectively). Renal and cardiac involvement were associated with negative serology (P = 0.019, 0.094 respectively). No new thrombotic events were found. Conclusions: Prevalence of positive ACLAs was 20% and positive LA 10%. Thrombotic events, pregnancy events, and cerebral involvement were associated with positive serology while renal and cardiac involvement with negative serology. We suggest screening SLE patients for the presence of APLAsand larger sample with longer follow up for their clinical manifestations.