[Retrospective study of primary IgA nephropathy with crescent formation and/or rapidly progressive glomerulonephritis in children].

OBJECTIVE: IgA nephropathy is the most common type of glomerulonephritis in the world. Its clinical and pathological manifestations vary. A few of the patients with IgA nephropathy present with rapidly progressive glomerulonephritis (RPGN) and/or crescent formation. Their conditions are serious and acute, but there are few reports on their characteristics, treatment and outcome. This study aimed to analyze the clinicalopathological features, treatment and prognosis of primary IgA nephropathy in children, to provide a reference for clinical diagnosis and treatment.

METHOD: A retrospective study was conducted in children with primary IgA nephropathy with crescent formation and/or rapidly progressive glomerulonephritis admitted to our department from 2000 to 2014. The patients meeting the inclusion and exclusion criteria were included. Patients were divided into RPGN group and non-RPGN group according to the clinical manifestations, crescent formation group and non-crescent group, crescentic IgA nephropathy group and non-crescentic IgA nephropathy group according to renal biopsy. Their clinical manifestations and pathological features, treatment and prognosis were compared.

RESULT: A total of 265 patients were recruited, 10 patients (3.8%) had RPGN, 151 patients (57.0%) had crescent formation, 19 cases (7.2%) showed crescentic IgA nephropathy.Compared with non-RPGN group, RPGN group showed more gross hematuria, higher serum creatinine, lower creatinine clearance correction at biopsy and follow-up, and more crescentic IgA nephropathy (P<0.05). The percent of patients who received methylprednisolone pulse and blood purification therapy in RPGN group is higher than that of non-RPGN group (P<0.05). Compared with non-crescent group, crescent formation group showed more gross hematuria at biopsy and follow-up, higher serum creatinine at biopsy, lower creatinine clearance correction, more 24-hour urinary protein at biopsy and higher serum creatinine at follow-up (P<0.05). The percentage of patients received more methylprednisolone pulse, oral steroids, cyclophosphamide pulse in crescent formation group was higher than that of non-crescent group (P<0.05). Compared with non-crescentic IgA nephropathy group, crescentic IgA nephropathy group showed more RPGN percent, higher serum creatinine, more 24-hour urinary protein at biopsy (P<0.05). The percentage of patients who received more methylprednisolone pulse and blood purification therapy in crescentic IgA nephropathy group was more than non-crescentic IgA nephropathy group (P<0.05). At follow-up, 20.0% of the patients with RPGN and crescent nephritis returned to normal renal function and the percent of crescent glomerulonephritis but not RPGN was 71.4%, RPGN but not crescent glomerulonephritis was 80.0%, crescent formation but not crescent nephritis was 87.5%.

CONCLUSION: In primary IgA nephropathy with crescent formation and/or rapidly progressive glomerulonephritis, the patients with both RPGN and crescentic IgA nephropathy showed the worst clinical manifestations, its prognosis was worst while the patients with crescent formation showed the mildest clinical manifestations and best prognosis.