Prognostic significance of platelet count in SLE patients

Hematological abnormalities, especially thrombocytopenia (TCP), are highly prevalent among patients with systemic lupus erythematosus (SLE) and at the same time it has been reported as a significant prognostic factor of SLE course. We further investigate the correlation between platelet count and the clinical manifestations and disease activity of SLE, in a cohort of Saudi Arabian female patients. A retrospective analysis was done for the medical records of 100 SLE female patients, selected from all patients diagnosed and treated for SLE at the Rheumatology outpatient clinics in Hera'a General Hospital, Holly Makkah, Saudi Arabia. The data collected from every patient's file included laboratory investigations (complete blood count, platelet parameters, ESR, anti-double-stranded DNA antibody, ANA), clinical manifestations, as well as SLE disease activity index (SLEDAI-2k) scores throughout a period of six sequential follow-up visits. Patients were divided into three groups according to the SLEDAI-2k: mild, moderate, and high-activity group. We found that, out of 100 patients, TCP was the most prevalent hematological abnormality evident in 15%, more than leucopenia (14%) and anemia (2%). TCP was acute in onset and associated with arthritis, neurologic manifestations, and nephritis. Platelet count showed a significant negative correlation with disease activity, in all of the three groups of patients. We concluded that platelet count has a negative correlation with disease activity in SLE patients, whatever the associated manifestations, and it should be considered as a prognostic factor, identifying patients with aggressive disease course.