RESUMO
In 78 children with idiopathic nephrotic syndrome, the levels of serum immunoglobulins were studied. In 45 cases with lipoid nephrosis, 7 with segmentary and focal sclerosis and in 26 with membranoproliferative glomerulonephritis, a reduction in per centum values of IgG were found in similar magnitude in the groups. Levels for IgA were not found abnormal and there was an increase in values for IgM exclusively in cases of lipoid nephrosis. There was no difference between disorders shown by cases of active lipoid nephrosis at the beginning or following relapse after some time of evolution. On the other hand it was found that disorders that appeared significantly in magnitude in cases undergoing remission, but specially in those with a greater time of evolution. The difference in these findings with those reported by other authors are attributed to multifactorial causes of lipoid nephrosis and it is supposed that disorders of immunoglobulins represent a functional defect of the lymphocytes T similar to that described as "immunodeficiency linked to chromosome X with high IgM". The association of lipoid nephrosis with certain types of locus HL-A suggest that these immunity alterations might signify a predisposing factor genetically transmitted and suggest the systematic study of these abnormalities in parents and siblings of patients with this disease.