Characteristics and associated risk factors of opportunistic infection in children with systemic lupus erythematosus in under-resourced areas

Objective Infection is a major factor in morbidity and mortality among pediatric systemic lupus erythematosus (SLE) patients, particularly opportunistic infections (OI), which can result in severe clinical outcomes. There is a scarcity of data regarding OI in children with SLE in resource-limited areas. This study aimed to determine the incidence of OI in childhood SLE, describe their characteristics, and identify associated risk factors. Methods This study is a retrospective and prospective study from January 2009 to November 2025 at King Chulalongkorn Memorial Hospital, Thailand. Data on demographics, clinical features, laboratory parameters, types of OI, and outcomes were analyzed. Conditional logistic regression analysis was used to identify risk factors for OI in pediatric SLE. Results Among 177 children with SLE, 38 patients developed OI. Person-year incidence of OI was 3.4 per 100 person-year (95% CI: 2.3-4.9). The most common OIs were Candida spp. (27.0%), Aspergillus spp. (13.5%), and Cytomegalovirus (CMV) (13.5%) with respiratory and mucocutaneous sites being the most frequently affected. Pulse intravenous methylprednisolone (IVMP) use during the past 3 months and high disease activity, defined as SLEDAI-2K score ≥ 11, were associated with an increased risk of OI in the multivariate model (adjusted OR, aOR 16.12; 95% CI 3.42-75.85 and aOR 3.46; 95% CI 1.44-8.31, respectively). Other variables, including cumulative prednisolone dose, cumulative cyclophosphamide exposure, complement 3 (C3) and C4 level, absolute lymphocyte count, and serum albumin, were not significantly associated with OI development after adjustment for potential confounders. Conclusion Fungal and CMV infections were common OI in pediatric SLE. This finding underscores the importance of clinical vigilance regarding OI and the implementation of preventive strategies in SLE patients with the recent pulse IVMP exposure or high disease activity.