Dr Joshua Choo1, Prof Andrew Mallett1,2, Dr Vikas Srivastava1, Dr Valli Manickam1, Dr Cassandra Rawlings1
1Townsville University Hospital, Townsville, Australia, 2James Cook University, Townsville, Australia
Biography:
Bio to come
Background:
Fibrillary glomerulonephritis (FGN) is a rare form of glomerulonephritis found in approximately 1% of native kidney biopsies. We report three cases of FGN in our regional centre in the past 5 years and their outcomes.
Case Report:
Three patients (one female and two males) aged 60-67 years presented with impaired kidney function and nephrotic range proteinuria. Serum creatinine on presentation ranged from 108 to 241µmol/L and urine protein-creatinine ratio between 677 to 997mg/mmol. Only one of the patients had microscopic haematuria. One of the patients had a history of pancreatic neuroendocrine tumour resected a year prior and the two remaining patients did not have any history of malignancy, autoimmune diseases or hepatitis. Viral serology and autoimmune screening were negative. FGN diagnosis was confirmed on kidney biopsy electron microscopy (EM) in two patients, with EM pending in the third patient. Light microscopy findings were heterogenous ranging from mesangial proliferative glomerulonephritis, mesangial sclerosis or focal segmental glomerulosclerosis. DnaJ homolog subfamily B member 9 (DNAJB9) immunohistochemistry was not available at the time of biopsy in the first patient but was positive in the other two patients.
Two patients were commenced on immunosuppression with high-dose corticosteroids and rituximab with one of them progressing to end-stage kidney failure eventually requiring haemodialysis after 10 months. The other had non-progression of kidney impairment one month post commencement of immunosuppression. The third patient elected against immunosuppression with slight progression of kidney impairment during conservative medical management.
Conclusion:
Detection of DNAJB9 has shown to be a diagnostic biomarker for FGN, alleviating reliance on EM. The optimal therapy for this rare disease which is associated with poor outcomes remains unclear and requires further studies.