Acute kidney injury due to glomerular haematuria and obstructive erythrocyte casts associated with thrombocytopaenia and thin basement membrane disease: a case report

Acute kidney injury due to thin basement membrane disease mimicking Deferasirox nephrotoxicity: a case report

BACKGROUND

Although the renal toxicity of Deferasirox, an oral iron chelator, has been reported to be mild, there have been reports of acute interstitial nephritis or Fanconi syndrome due to this agent. Thin basement membrane disease (TBMD) is a hereditary disease characterized primarily by hematuria, with gross hematuria also observed in about 7% of cases. We herein report a case of TBMD that presented with acute kidney injury and gross hematuria during treatment with Deferasirox.

CASE PRESENTATION

The patient was a 63-year-old man who had been diagnosed with myelodysplastic syndrome 6 years ago. He had started taking Deferasirox at 125 mg due to post-transfusion iron overload 6 months ago. Deferasirox was then increased to 1000 mg three months ago. When the serum creatinine level increased, Deferasirox was reduced to 500 mg three weeks before hospitalization. Although the serum creatinine level decreased once, he developed a fever and macroscopic hematuria one week before hospitalization. The serum creatinine level increased again, and Deferasirox was stopped four days before hospitalization. He was admitted for the evaluation of acute kidney injury and gross hematuria. Treatment with temporary hemodialysis was required, and a kidney biopsy was performed on the eighth day of admission. Although there was no major abnormality in the glomeruli, the leakage of red blood cells into the Bowman's space was observed. Erythrocyte cast formation was observed in the tubular lumen, which was associated with acute tubular necrosis. The results of an electron microscopic study were compatible with TBMD.

CONCLUSION

Although Deferasirox is known to be nephrotoxic, gross hematuria is relatively rare. When we encounter a case of acute kidney injury with gross hematuria during treatment with Deferasirox, TBMD should be considered as a possible cause of gross hematuria.

The pathological spectrum associated with the ultrastructural finding of thin glomerular basement membrane: A tertiary medical city experience and review of the literature

BACKGROUND

Thin glomerular basement membrane (GBM) has been noted in several glomerular diseases including IgA nephropathy, focal segmental glomerulosclerosis (FSGS), Fabry's disease, and Alport's syndrome. We conducted this study to investigate the pathological ultrastructural spectrum of thin GBMs, to identify associated diseases, and to measure the GBM thickness in thin GBMs in our adult population.

MATERIALS AND METHODS

All renal biopsies with thin GBM, diagnosed between 2010 and 2016, were retrieved and reviewed.

RESULTS

Of 24 cases, 50.0% were diagnosed with FSGS, 12.5% with IgA nephropathy, 8.3% with tubulointerstitial nephritis, 4.2% with acute thrombotic microangiopathy, 4.2% with focal global sclerosis, 4.2% with lupus nephritis, and 16.7% with only thin GBM disease. Mean GBM thickness was 213.4 ± 24.7 nm. Mean interstitial fibrosis/tubular atrophy percentage (IF/TA) was 27.9 ± 22.2%. There was no significant correlation between GBM thickness and patients' age or IF/TA percentage.

CONCLUSION

The association of thin GBM with FSGS and IgA nephropathy is high. Morphometric analysis of the GBM thickness should be made routine, noting that ethnic variations in the GBM thickness are reported. Cases of thin GBM should be reported to facilitate proper diagnosis and institute the most appropriate treatment.