HDCN Article Review/Hyperlink

Midtvedt K, Stokke ES, Hartman A

Successful long-term treatment of post-transplant erythrocytosis with losartan

Nephrol Dial Transplant (Dec) 12:2495-2497 1996

The cause of post transplant erythrocytosis (PTE) is unknown. Although some have postulated that there is EPO overproduction by the native kidneys, allograft, or liver, others have not found elevated EPO levels in PTE patients. ACE inhibitors are successfully used to treat such patients, and again, the mechanism is unclear. It is unclear if ACE inhibitors are acting on EPO levels (probably not), and whether they are acting via an effect on AII receptors or via their effects on bradykinin.

In this report, Midvedt et al found that mean Hgb in a patient with PTE decreased from about 16.5 to 15 g/dl after losartan 25 mg daily, with a further drop when the dose was increased to 50 mg. Stopping losartan resulted in a rebound rise in the Hgb, although not to pretreatment levels. EPO levels were not measured. The authors conclude that losartan is safe and effective for PTE patients.

In a letter to NDT in the same (December 1996) issue, PJ Conlon et al (Nephrol Dial Transplant 12:2524-2525, 1996) prospectively gave losartan 50 mg daily to 7 renal allograft recipients with Hct values > 53%. Mean Hct decreased to 49%, and 6/7 patients had a decrease in Hct.

Comment: Together these studies strongly suggest that AII-mediated mechanisms and not bradykinin are responsible for the Hct lowering effects of ACE inhibitors in PTE, and increase our therapeutic armamentarium for this condition. (John T. Daugirdas, M.D., University of Illinois at Chicago)