Fibrillary and Immunotactoid Glomerulopathies By Frank O'Brien, MD, Washington University in St Louis Reviewed / Revised Jun 2023 View Patient Education Diagnosis Treatment Prognosis Topic Resources Immunotactoid Glomerulopathy Fibrillary Glomerulopathy... Fibrillary Glomerulopathy... Fibrillary Glomerulopathy... Fibrillary and immunotactoid glomerulopathies are rare conditions defined pathologically by organized deposition of nonamyloid microfibrillar or microtubular structures within the renal mesangium and basement membrane.