Membranous nephropathy and severe acute kidney injury following influenza vaccination

Immunization with influenza vaccine remains an important global health strategy to prevent outbreaks and epidemics of seasonal influenza. Influenza vaccine has rarely been associated with vasculitis, acute kidney injury (AKI) and nephrotic syndrome (NS). Glomerular diseases following influenza vaccination have also been rarely reported. We report a patient who developed acute-onset massive proteinuria with NS and severe AKI soon after receiving the 2009 H1N1 influenza vaccine. Kidney biopsy showed membranous nephropathy (MN) and acute interstitial nephritis (AIN). Optimal management of glomerular diseases or AIN following influenza vaccination is not known. Our patient responded well to an initial course of oral corticosteroid therapy with normalization of serum creatinine level but had a relapse of NS with AKI soon after completion of corticosteroid therapy. A repeat kidney biopsy revealed MN and resolved AIN. A subsequent prolonged course of oral corticosteroids resulted in complete clinical remission of the NS as well as normalization of renal function. Long-term response to corticosteroid therapy in such cases is not known. However, our patient continued to remain in clinical remission with normal renal function, five years after the initial treatment.