Fibrillary and immunotactoid glomerulopathies in the Hunter region: a retrospective cohort study.

Background: Fibrillary (FGN) and immunotactoid (IT) glomerulonephritis are uncommon. Aims: To evaluate the prevalence, clinicopathological correlations and outcomes of FGN and IT in our regional centre in Australia. Methods: We interrogated a renal biopsy database for cases of FGN and IT from 2000 to 2020. Data included demographics, serum creatinine, haematuria status, proteinuria, comorbidities and histopathological findings. Results: We had 14 cases of FGN and t of IT. The mean presenting age was 59.8 years, and 42.9% were males. No patients with FGN had dysproteinaemia, whereas both patients with IT had chronic lymphocytic leukaemia. At presentation, 75% of patients with FGN and both patients with IT had haematuria; all had proteinuria. Mean albumin‐creatinine ratio at presentation was 254 mg/mmol for FGN and 604 mg/mmol for IT. Mean presenting serum creatinine was 149 μmol/L for FGN and 95 μmol/L for IT. Four patients with FGN (28.6%) received immunomodulatory therapy. The prognosis of FGN was poor, with six patients (46.2%) reaching end‐stage kidney disease after a median of 42 months (range 1–96 months). All patients presenting with proteinuria <30 mg/mmol entered complete remission; patients with higher‐grade proteinuria exhibited progressive chronic kidney disease. Patients with IT had complete remission with treatment of underlying haematological disease. Conclusion: FGN is rare, with poor response to immunomodulatory therapy. It carries poor renal prognosis. Less proteinuria at diagnosis may predict a more benign disease course. IT is associated with haematological malignancy and carries better prognosis and response to treatment. [ABSTRACT FROM AUTHOR]