The Importance of Immunohistochemical Staining with DNAJB9 for the Diagnosis of Fibrillar Glomerulonephritis

Fibrillary Glomerulonephritis (FGN) is a rare glomerulopathy, corresponding to less than 1% of all renal biopsies performed. The pathogenesis mechanisms of FGN are still not completely understood and most cases are considered idiopathic. The clinical presentation is characterized by proteinuria, hematuria, arterial hypertension and renal failure. The evaluation of FGN is a diagnostic challenge in the practice of the pathologist, because there are no morphological characteristics with highly specific or pathognomonic lesion. The use of a sensitive and specific biomarker can make an important contribution to renal pathology and the differential diagnosis of diseases with fibrillar deposits. In this contexto, DNAJB9 can be investigated by immunohistochemical technique and is useful for the diagnostic definition of FGN.