Assessment of Serum Factor B, Serum Opsonins, Granulocyte Chemotaxis, and Infection in Nephrotic Syndrome of Children

Abstract

Chemotactic and opsonic functions and concentrations of factor B were investigated in serum from 18 steroid-sensitive and four steroid-resistant pediatric patients with nephrotic syndrome during various clinical states. Placement of sera from nephrotic children in relapse in the stimulant compartment of Boyden chambers resulted in chemotaxis scores that were significantly lower (P < 0.001) than scores for remission or control sera. Scores observed for zymosan-activated sera of relapsing nephrotic patients were also diminished compared with scores for sera from the same patients during remission or scores for sera from adult controls. In a modified chemiluminescence assay, opsonic activity for zymosan in relapse sera was diminished significantly (P < 0.05, P < 0.01) compared with that in remission and control sera respectively. Chemiluminescent values increased in all cases in remission sera compared with those in the respective relapse sera. As demonstrated by indirect immunofluorescence, C3 zymosan deposition in relapse sera was generally decreased compared with that in the respective remission sera or in control sera. Concentrations of factor B (mean ±SE, in mg/dl) in relapse sera (9.13 ± 1.0) were significantly lower (P < 0.001) than concentrations in remission sera (22.1 ± 1.3) or in adult (control) sera (23.1 ± 1.4). Systemic bacterial infection of nephrotic patients in relapse states was related to decreased values for serum chemotaxis, chemiluminescence, and immunofluorescence and diminished concentrations of factor B in serum.