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

Fibrillary (FGN) and immunotactoid (IT) glomerulonephritis are uncommon.

To evaluate the prevalence, clinicopathological correlations and outcomes of FGN and IT in our regional centre in Australia.

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.

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.

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.