A 3-year-old boy with steroid-resistant nephrotic syndrome who was diagnosed with severe lupus nephritis one year later: a case report

Abstract

We experienced a boy who presented with steroid-resistant nephrotic syndrome at the age of 2 years and was diagnosed with severe lupus nephritis 1 year later. The first renal biopsy showed secondary membranous nephropathy and fluorescent antibody showed a full house pattern, but he did not meet the diagnostic criteria for systemic lupus erythematosus (SLE). We administered prednisolone, angiotensin converting enzyme inhibitor and angiotensin II receptor blocker to him, the severe proteinuria disappeared. A year later, severe proteinuria and serological findings appeared, and he was diagnosed with SLE. The second renal biopsy showed lupus nephritis type IV+type V, which was already mainly chronic lesion. In the case of type V lupus nephritis, it can be difficult to diagnose SLE. However, delayed SLE has a poor prognosis. This is the importance of renal biopsy for SRNS because there is delayed SLE with SRNS onset. If pathological findings suggest lupus erythematosus type V, we should have regular urinalysis and blood tests for early diagnosis.