Acute Idiopathic Immune Complex Mesangioproliferative Glomerulopathy in an Adult; Resurge of the Fallen

Abstract

Background: Idiopathic form of mesangioproliferative glomerulopathy (MesPGP) was excluded by the standardized classification and reporting of glomerulonephritis (Mayo clinic consensus) in 2016 aiming to limit such group only to IgA nephropathy, IgA vasculitis, infection-related GP, lupus nephritis, and fibrillary GP with polyclonal Ig deposits in an attempt to aid in treatment. The case: A 32-year-old man presented with severe hypertension that was associated with progressive renal failure (serum creatinine at 358 umol/L), proteinuria and hematuria. Clinical assessment and laboratory testing did not show evidence of infection and autoimmune disease. Kidney biopsy showed MesPGP with 39% glomerulosclerosis and 60% interstitial fibrosis. Immunohistochemical studies showed 2(+) IgG and IgA deposits over the peripheral capillary loops not mesangium. C3 and C1q were negative. Electron microscopy scanning showed subepithelial, subendothelial and mesangial electron dense deposits. Hence, diagnosis of idiopathic MesPGP was established. He improved after intravenous Solumedrol followed by a tapering dose of Prednisone with Mycophenolate mofetil for 3 months. Subsequently, he remained in remission up to 1 year with Rituximab alone and will be using it for a minimum of 2 years. Conclusion: Acute idiopathic immune complex MesPGP should be reincluded in classification of glomerulopathy and was amenable to immunosuppressive therapy.