Persistent Antinuclear Antibodies Positivity Predicts Progression to Systemic Lupus Erythematosus in Paediatric Autoimmune Cytopenias: A Retrospective Cohort Study.

Objective: Autoimmune cytopenias (AIC) may be associated with positive antinuclear antibodies (ANA) and can precede the onset of systemic lupus erythematosus (SLE). This study assessed ANA as a predictive factor for progression to SLE in adolescents with AIC. Methods: Medical records from a paediatric haematology referral centre were retrospectively reviewed. Presence of ANA (titer>1:80) was recorded in 90 adolescents and children with AIC. Possible progression to SLE was evaluated in the group. Results: A total of 90 patients with AIC were included, with a median age of 9 years and a predominance of ITP (67/90). ANA positivity was identified in 35/90 patients with AIC, most frequently in females (25/35). Among ANA-positive patients, 6/35 eventually developed SLE, whereas none of the ANA-negative patients progressed to SLE. Of the patients who developed SLE, the majority were female (5/6), with 5/6 initially diagnosed with autoimmune thrombocytopenia and 1 with Evans syndrome. The median age at AIC onset for those who later developed SLE was 10.4 years, and the median time interval between AIC diagnosis and SLE onset was 2.5 years. Additionally, 10/35 ANA-positive patients met high-risk criteria for future SLE according to Lambers et al. (2020), despite not fulfilling EULAR/ACR-2019 criteria for SLE at the time of review. Conclusions: Persistent ANA positivity in patients with AIC strongly predicts subsequent SLE, particularly in females older than 10 years with ITP. This finding warrants further investigation in larger, prospective studies, including follow-up of patients transitioning to adult care, as SLE may manifest later in adulthood.