Clinical characteristics of relapsing idiopathic nephrotic syndrome associated with influenza virus infection or influenza virus vaccine in six pediatric patients

Abstract

Although influenza virus (flu) vaccines or infections can precipitate the relapse of idiopathic nephrotic syndrome (NS) in children, no data are available on the backgrounds of NS patients. We report six pediatric cases who experienced NS relapses associated with flu vaccines or infections. The patients were all males. Three experienced NS relapses associated with flu vaccination (vaccine relapse patients), and three relapsed following flu infections (infection relapse patients). In all three vaccine relapse patients, the period from vaccination to disease onset or the last relapse was less than 6 months, whereas it was less than 6 months in only three of 15 vaccines in the control group. In all three infection relapse patients, the period between infection and disease onset or the last relapse was less than 6 months, whereas this period was more than 6 months in all three infected patients in the control group. Flu infections or vaccines may precipitate the relapse of NS, and this may be affected by the disease severity in each child. A prospective multicenter study of NS relapse associated with flu infection or vaccination is required.