Value of repeat renal biopsy in the evaluation of AL amyloidosis patients lacking renal response despite of complete hematologic remission: a case report and literature review

Backgrounds: Published literatures on repeat renal biopsy of AL amyloidosis have basically reached a consensus that amyloid material deposit does not disappear or diminish after satisfactory hematologic response, regardless of renal response. However, the need of a repeat renal biopsy in such situation is still controversial.

Case presentation: Here we reported a case of histologically confirmed λ Type renal AL amyloidosis who had been classified as Stage I and low risk at initial diagnosis. The patient received a total of six courses of CyBorD chemotherapy. She had achieved complete hematologic remission after two courses of chemotherapy but consistently had large amount of proteinuria over 10 g/day during follow up. A repeat renal biopsy was performed nine months after the first one and indicated mild to moderate increase of amyloid deposits as well as significant glomerulosclerosis and interstitial lesions, suggesting a lack of histological renal improvement despite her satisfactory hematologic response.

Conclusions: This case indicated renal involvement in AL amyloidosis could progress after successful hematologic treatment, and supported the value of repeat renal biopsy in the evaluation of AL amyloidosis patients lacking renal response despite of complete hematologic remission.