Childhood nephrotic syndrome associated with diffuse mesangial hypercellularity. A report of the Southwest Pediatric Nephrology Study Group.

Clinico-pathologic correlations and therapeutic responses were examined in 29 children with idiopathic nephrotic syndrome (INS) and diffuse mesangial hypercellularity (DMH). At the onset of INS, microscopic hematuria was noted in 89%, hypertension in 46%, and impaired renal function in 24% of patients. Semiquantitative grading of the renal histopathology revealed mild (1+), moderate (2+), and severe (3+) grades of DMH in 13, 11, and 5 patients, respectively. Higher grades of DMH were associated with glomerular electron dense deposits and severe hematuria. Twelve of 24 steroid-treated patients had complete remissions of INS, and three had partial remissions. Of the nine patients resistant to steroid therapy, six received chlorambucil or cyclophosphamide but none responded. Resistance to steroids was associated with more severe DMH and the presence of glomerular electron dense deposits. The presence of positive immunofluorescence was unrelated to steroid responsiveness or outcome. After a mean follow-up of 29 months, proteinuria was present in ten of 26 patients but only two had impaired renal function. Our limited follow-up of these patients with INS and DMH suggests that initial response to steroid therapy is a better indicator of subsequent clinical course than the degree of DMH.