Resistance factors for the treatment of immunoglobulin A nephropathy with diffuse mesangial proliferation.

AIM: Some patients with severe immunoglobulin A nephropathy (IgAN) are resistant to multi-drug combination therapy; however, there have been few reports on the risk factors for non-responsiveness to treatment for severe IgAN. We, therefore, evaluated the risk factors for non-responsiveness to treatment in cases of severe IgAN.

METHODS: We collected data on 44 children who had been diagnosed with IgAN with diffuse mesangial proliferation and treated with multi-drug combination therapy. The children were divided into two groups based on the prognosis at the latest follow-up. Group 1 consisted of 30 children with normal urine and nine children with minor urinary abnormalities and Group 2 consisted of four children with persistent nephropathy and one child with renal insufficiency. The clinical, laboratory, and pathological findings for both groups were analyzed.

RESULTS: The age at the onset in Group 2 was higher than that in Group 1. C3 deposits and high chronicity index values at the first renal biopsy were more frequently found in Group 2 than in Group 1 patients. IgA deposits, serum IgA and myeloid-related protein (MRP) 8/14 levels, and glomerular and interstitial MRP8+CD68+ scores at the second biopsy were all higher in Group 2 than in Group 1 patients.

CONCLUSIONS: Our results, although based on only a small number of patients in a retrospective study, suggest that age, presence of C3 deposits and interstitial changes at the onset, and persistent renal inflammatory activation may be risk factors for non-responsiveness to treatment for IgAN with diffuse mesangial proliferation.