Kidney Involvement in Patients with CMML, MPN

A study published in Kidney International Reports found that kidney involvement is heterogenous in patients with chronic myelomonocytic leukemia (CMML) and BCR-ABL-negative myeloproliferative neoplasms (MPNs), and a kidney biopsy may help identify new molecular targets to prevent the development of kidney fibrosis.

This case series retrospectively assessed patients with myeloid neoplasms who were referred to the Toulouse University Hospital Nephrology Unit in France between January 2010 and December 2020 and were diagnosed with acute kidney injury (AKI), chronic kidney disease, or urine abnormalities.

Over 11 years (mean, 7.7 years since malignancy diagnosis), 18 consecutive patients developed kidney disease, including eight with CMML, seven with essential thrombocytosis, one with polycythemia vera, and two with myelofibrosis.

Twelve patients had AKI at presentation. Eight patients had glomerular presentation (high-range proteinuria, 33%; microscopic hematuria, 56%). Fourteen patients underwent kidney biopsy, which showed various patterns, including pauci-immune glomerulosclerosis (n=5), extramedullary hematopoiesis (n=6), or tubular atrophy and interstitial fibrosis with polymorphic inflammation (n=8).

Immunostaining of CD61 confirmed the infiltration of megakaryocytes within glomeruli or interstitium in five of eight patients; other pictures of glomerulopathy were identified in three patients. One patient had massive kidney infiltration by CMML.

After a mean follow-up of 24 months, 11 patients (61%) had stable malignancy; however, 22% of patients progressed to end-stage renal failure. The remaining patients had persistently reduced kidney function. There was no association between malignancy and renal presentation and outcomes, according to the authors.

“Regular screening for proteinuria and renal failure should be proposed to all patients with myeloid neoplasms in order to detect the kidney disease early and adapt the treatment of the malignancy,” the researchers concluded.