Introduction
Changes in immunity are complex in idiopathic nephrotic syndrome (NS), affecting the cellular and the humoral balance of specific immunity which may impair the response to infection, so at least half of relapses triggered by infection. We aimed to describe the rate and type of infection in idiopathic nephrotic syndrome cases admitted with activity to our Nephrology unit Patients and methods
 This is a cross-sectional, case control study; 90 NS cases were admitted with activity, they were subdivided in to two groups according to presence or absence of infection; group I 60 NS cases with infection and group II 30 NS cases without infection. We evaluated every subject for the activity of disease, type of infections, the occurrence of complications and fate of therapy and routine laboratory tests were done.
 
Result
The most common type of infection was gastroenteritis (GE) (25%) of infected cases, 2nd most common was Urinary tract infection (UTI) (21.7%), While Pneumonia representatives (15%) of infection. There was no significant pathogen in (61.66%) of all infected cases, the most common pathogen is E.coli (25%), followed by Shigella (6.66%), pneumococci (3.33%), Klebsiella (1.66%) and Proteus (1.66%). The most often used antibiotic before culture is (Ampicillin, sulbactam followed by cefotaxime) and after culture (Cefepime, Meronem, ceftazidime and Vancomycin). Conclusion
We concluded that 66.6% of admitted children with relapsed NS were due to infection, the most common type of infection is GE, followed by UTI, Viral infection represents were more common than bacterial ones, the most common isolated bacteria  after culture were E.coli, Shigell and pneumococci.