Analysis of the clinical characteristics of arthritis with renal disease caused by a NPHS2 gene mutation.

The co-existence of juvenile idiopathic arthritis (JIA)/rheumatoid arthritis (RA) and focal segmental glomerulosclerosis (FSGS) is rare, and the existence of co-pathogenesis remains unknown. In this study, we analyzed the clinical and gene mutation characteristics of a patient with JIA and FSGS caused by a NPHS2 gene mutation, and evaluated the potential connections between these two diseases. We summarized the clinical manifestations, related examination results, and gene mutation characteristics of the patient who presented at our center and six reported cases of arthritis with renal disease. Most of the cases were polyarticular arthritis with varying degrees of renal damage (hematuria, proteinuria, and renal dysfunction) and different prognoses. Among these patients, two developed end-stage renal disease (ESRD), with one dying as a result, while the other patients had a relatively good prognosis. Patients with a family history of renal disease had a poor prognosis. After excluding occasional factors and drug influences, our analysis indicated the existence of co-pathogenesis of arthritis with renal damage (especially FSGS). NPHS2 mutations might account for the family aggregation. Therefore, evaluation of more clinical cases is necessary to further clarify the underlying co-pathogenesis of these diseases.