Comprehensive Analysis of Thrombocytopenia in Systemic Lupus Erythematosus: Prevalence, Immunological Correlations, and Mortality Outcomes in the Oman Lupus Cohort

Background: In systemic lupus erythematosus (SLE), thrombocytopenia is a common hematological complication associated with severe disease manifestations and increased mortality. Objectives: The study aimed to investigate the prevalence of thrombocytopenia in the Oman lupus cohort and explore its correlation with clinical, immunological, and epidemiological characteristics, as well as mortality and survival outcomes. Methods: The study forms a section of the Oman Lupus Study, which is a longitudinal research initiative that includes 1 160 patients diagnosed with SLE between January 2006 and February 2020. The patients were evaluated for the prevalence of thrombocytopenia, which was further analyzed in relation to epidemiological and clinical characteristics, laboratory profile, survival, and mortality outcomes. Results: Thrombocytopenia was found in 22.5% of patients (262/1 160), with no significant difference between males (12%) and females (88%, p = 0.642). There were significant correlations between thrombocytopenia and antiphospholipid antibodies, as well as organ involvement, such as renal (5.3% vs. 0.6%, p = 0.000), neuropsychiatric (30.9% vs. 17.9%, p = 0.000), and respiratory complications (25.6% vs. 16.4%, p = 0.001). A similar prevalence rate was identified between pediatric and adult patients (20.2% vs. 22.8%, p = 0.490). It has been demonstrated that the mortality rate in thrombocytopenia patients was significantly higher (11.1% vs. 2.9%, p = 0.000), translating to a nearly fourfold increased risk. The Kaplan–Meier curve indicated that patients with thrombocytopenia had a reduced survival rate. Conclusions: Thrombocytopenia impacts nearly a quarter of lupus patients and is strongly associated with organ involvement and increased mortality risk, irrespective of gender or age. These findings underscore the necessity for additional research and specialized guidelines to enhance outcomes in this high-risk group.