Prediction of steroid response in nephrotic syndrome by humoral immunity assessment

The purpose of this study was to estimate the serum levels of IgG, IgM, and IgA in nephrotic syndrome (NS) cases, in activity or in remission, and to detect their levels in relation to steroid response by evelautingthe relationship between IgG/IgM ratio and response to steroids. We investigated 27 cases with NS in activity and in remission and 20 healthy children as controls. Group A included 16 NS patients (12.3±1.4 years) who were steroid-resistant, frequent relapsers, or steroid dependent. Group B included 11 steroid-sensitive NS patients with a mean age of 11.6±2.1 years. Group C included 20 healthy children with a mean age of 12.1±2.3 years who were the control group. We found lower serum IgG level in NS cases compared with the control group; and it was lower in activity than in remission. The levels were lower in Group A compared with those of Group B. Serum IgG levels in Group A were as follows: in activity, 2.29±1.13 g/L and in remission, 4.3±2 g/L. In Group B, they were 6.2±1.2 g/L and 6.5±1.15 g/L in activity and in remission, respectively, and 11.8±2.5 g/L in the healthy control group (P<0.05). There was a direct correlation between serum albumin and serum IgG. We found no significant difference in serum IgM and IgA levels among studied groups whether in activity or in remission. Serum IgG/IgM ratio was lower in activity and in remission in the patient groups than in the control group as it was 9.3±4.7 in healthy subjects. It was 1.8±1.5 in Group A in activity and 3.2±2 in remission, and in Group B 4.8±2.39 in activity and 4.8±2.4 in remission. We conclude that IgM and IgA show no significant difference in NS patients. Serum IgG is lower in NS than in the control group and is much lower in activity than in remission. It is lower in patients with poor steroid response. We propose a predictive value of IgG/IgM ratio in activity, that is, the higher the IgG/IgM ratio in activity, the better the prognosis.