Profile of juvenile systemic lupus erythematosus patients with a special reference to monogenic lupus and lupus nephritis: a cross-sectional study.

To study the clinical, laboratory profile and outcome of juvenile Systemic Lupus Erythematosus (jSLE) patients at a tertiary care centre in South India. A retrospective review of the medical records of all jSLE patients visiting the Pediatric Immunology and Rheumatology Unit, Aster CMI Hospital, India from February 2017 to December 2023 was performed. The clinical characteristics, treatment and outcomes were recorded and tabulated. Seventy patients diagnosed with jSLE were included in the study. The female-to-male ratio was 4.4:1. Mean age at onset and delay in diagnosis were 120.1 (+/- 56.8) and 11.7 (+/- 22.7) months respectively. The median follow-up period was 13 months (range 4, 29 months). Nine patients presented with early onset SLE (< 5 years). Most common manifestations were constitutional symptoms (n = 56), followed by haematologic (n = 55), and mucocutaneous(n = 50) involvement. Immunological workup showed SLE-specific antibody positivity in 38 patients, hypocomplementemia in 40 patients, and anti-phospholipid antibody positivity in 13 patients. Mortality was observed in five patients with LN while there was no mortality in the non-nephritis group (p 0.004). C1q deficiency was the most common cause of monogenic lupus seen in 5/9 patients; protein kinase C delta (PRKCD) defect and chronic granulomatous disease (CYBB mutation) were seen in one patient each. We describe a large cohort of jSLE from Southern India. Lupus nephritis was noted in 35.7% of our cohort and had a direct correlation with mortality. 10% of patients had monogenic lupus. Serious infections were more frequent in patients with monogenic lupus.