Abstract
Systemic mastocytosis is characterised by tissular infiltration and a cytokine storm due to mast cells excessive proliferation and activation. Herein, we report an extraordinary case of AH1N1 influenza post-viral glomerulonephritis occurring in the course of an aggressive systemic mastocytosis with an associated hematological neoplasm. Because of a multisystemic involvement including the liver and lungs, we treated mastocytosis with midostaurin (multiple inhibitor of kinase protein), anti H1/H2 blockers and dexamethasone as first line treatment. One month later and despite vaccination, he developed a severe acute lung injury with respiratory distress due to AH1N1 influenza in association with the nephrotic syndrome. Kidney biopsy disclosed a membranoproliferative glomerulonephritis that was successfully treated with mycophenolate mofetil. Only a few cases of influenza post-viral or post-vaccination glomerulonephritis are documented in the medical literature. This is an exceptional association of uncommon conditions occurring within only a few months in the same patient.