A study of the relationship between childhood nephrotic syndrome and allergic diseases.

The incidence of atopic diseases in 206 children with nephrotic syndrome (NS) was studied. Boys with NS had three times higher incidence of bronchial asthma than the general population. There was no difference in the girls. Both boys and girls with NS had about three times more allergic rhinitis and ten times more atopic dermatitis than the general population. In NS patients with associated allergic disease, skin test and allergen-specific IgE antibodies by radioallergosorbent test (RAST) were performed. Most of the patients with dust mites (Dermatophagoides pteronyssinus, Dermatophagoides farinae), egg white, or cow's milk protein-specific antibodies had positive skin tests. One hundred of the 206 children with NS received renal biopsies and serum IgE levels were measured. During the acute nephrotic phase the geometric mean serum IgE levels in minimal change nephrotic syndrome (MCNS), IgM mesangial nephropathy (IgMN), hepatitis B virus-associated membranous nephropathy, and treatment-responsive focal segmental glomerular sclerosis patients were all significantly elevated, in descending order of significance. These high serum IgE levels decreased in remission of NS and elevated again during relapse. The relationship between high serum IgE levels in NS patients and the incidence of allergic diseases showed that one third to one fourth of either IgMN or MCNS patients developed allergic diseases. These results suggest that NS patients had a higher allergic disease incidence. Serum IgE level may serve as one of the prognostic factors. However, an increase in the IgE level may be a reflection of body immunoregulatory imbalance that plays a direct pathogenic role in the occurrence of NS and proteinuria.