International cohort of 382 children with lupus nephritis - presentation, treatment and outcome at 24 months

Background Children with lupus have a higher chance of nephritis and worse kidney outcome than adult patients. Methods We retrospectively analyzed clinical presentation, treatment and 24-month kidney outcome in a cohort of 382 patients (<= 18 years old) with lupus nephritis (LN) class >= III diagnosed and treated in the last 10 years in 23 international centers. Results The mean age at onset was 11 years 9 months and 72.8% were females. Fifty-seven percent and 34% achieved complete and partial remission at 24-month follow-up, respectively. Patients with LN class III achieved complete remission more often than those with classes IV or V (mixed and pure). Only 89 of 351 patients maintained stable complete kidney remission from the 6(th) to 24(th) months of follow-up. eGFR >= 90 ml/min/1.73 m(2) at diagnosis and biopsy class III were predictive of stable kidney remission. The youngest and the oldest age quartiles (2y-9y, 5m) (14y, 2m-18y,2m) showed lower rates of stable remission (17% and 20.7%, respectively) compared to the two other age groups (29.9% and 33.7%), while there was no difference in gender. No difference in achieving stable remission was found between children who received mycophenolate or cyclophosphamide as induction treatment. Conclusion Our data show that the rate of complete remission in patients with LN is still not high enough. Severe kidney involvement at diagnosis was the most important risk factor for not achieving stable remission while different induction treatments did not impact outcome. Randomized treatment trials involving children and adolescents with LN are needed to improve outcome for these children.