An association between membranoproliferative glomerulonephritis and metastatic colorectal carcinoma: a case report.

BACKGROUND: Membranoproliferative glomerulonephritis is a common pattern of glomerular injury in monoclonal gammopathy, but has only rarely been associated with solid organ tumors, mainly lung, renal, gastric, breast, and prostate. There have been two reported cases of membranoproliferative glomerulonephritis associated with adenocarcinoma of the colon and rectum, although the association may be coincidental. We report a case where nephrotic syndrome due to membranoproliferative glomerulonephritis developed in a patient with colorectal carcinoma and elucidate some of the pathophysiological mechanisms underpinning this presentation. CASE PRESENTATION: A 54-year-old white man with a history of adenocarcinoma of the colon with metastasis to the liver and ureter presented with a 1-week history of bilateral pedal edema, and worsening hypertension and renal function. A renal biopsy confirmed membranoproliferative glomerulonephritis type I. Curative therapy for the malignancy was not possible, so treatment was commenced with prednisolone with consequential biochemical improvement in renal function and proteinuria, although his serum albumin remained low. CONCLUSIONS: This case report illustrates an association between membranoproliferative glomerulonephritis and metastatic colorectal carcinoma and adds to the evidence to consider malignancy to be an underlying pathology among newly diagnosed cases of nephrotic syndrome. In the clinical setting, treatment of the underlying malignancy should be first considered in patients with a tumor presenting with kidney disease which is suspected to be paraneoplastic in etiology.

Expression of Bcl-xL and Mcl-1 in the nonmelanoma skin cancers of renal transplant recipients.

OBJECTIVES: This study aims to investigate how immunosuppression influences the protein expression of antiapoptotic members of the Bcl-2 family-namely, Bcl-xL and Mcl-1-in nonmelanoma skin cancer (NMSC) and the peritumoral epidermis of renal transplant recipients. METHODS: NMSC and peritumoral epidermis protein expression of Bcl-xL and Mcl-1 were assessed by immunohistochemistry in renal transplant recipients receiving tacrolimus or sirolimus and the general population not receiving immunosuppression. RESULTS: NMSC from renal transplant recipients compared with patients not receiving immunosuppressant medications had a reduced Bcl-xL expression intensity (P = .042). Mcl-1 expression intensity in NMSC was decreased in tacrolimus-treated patients compared with sirolimus-treated patients and the nonimmunosuppressed population (P = .024). Bcl-xL expression intensity was increased in peritumoral epidermis compared with NMSC (P = .002). CONCLUSIONS: It was shown for the first time that Bcl-xL and Mcl-1 expression are widespread in the peritumoral epidermis and NMSC of renal transplant recipients. Importantly in NMSC, Bcl-xL expression was reduced with immunosuppression exposure, and Mcl-1 expression was reduced in tacrolimus-treated compared with sirolimus-treated patients.