Dysfunction of polymorphonuclear leukocytes in uremia: Role of parathyroidhormone

Polymorphonuclear leukocytes (PMNLs) from uremic patients have elevated bas al levels of cytosolic calcium ([Ca2+]i), reduced calcium signal after acti vation of Fc gamma RIII receptor, and impaired phagocytosis. Chronic excess of parathyroid hormone (PTH) in uremia mediates its effect on PMNL's metab olism and function through the sustained elevation of their [Ca2+]i. Becaus e calcium channel blockers interfere with this effect of PTH on PMNLs, trea tment of patients on hemodialysis with verapamil, nifedipine, or amlodipine was associated with an improvement in metabolism and phagocytosis of FMNLs in humans. The therapy with calcium channel blockers should be continued i n order to maintain its beneficial effects.