Is adult idiopathic nephrotic syndrome food allergy? Value of oligoantigenic diets.

To evaluate the prevalence of food hypersensitivity in idiopathic nephrotic syndrome (INS), an oligoantigenic diet was given for 10 days to 13 patients with INS who had not steadily responded to corticosteroids; 5 of these patients were corticodependent, 3 were corticoresistant and 5 had multiple relapses. A history of allergy was present in 8 cases and an increase in total serum IgE levels in 6. Sensitivity to food antigens was documented by skin tests in 5, by the radioallergosarbent test (RAST) in 5 and by the human basophil degranulation test (HBDT) in 11. At the end of the oligoantigenic diet, proteinuria was significantly reduced in the 13 patients as compared to the initial level. It decreased by more than 50% in 9 patients and disappeared completely in 5. It seems that an oligoantigenic diet is helpful in cases of INS that do not respond to corticosteroids. This argues for a role of food hypersensitivity in this disease and suggests that avoidance of specific foods on the longer term may be of benefit. This diet must be tried in INS before the initiation of immunosuppressive therapy.