Intraperitoneal therapy with interferon-alpha in CAPD patients with relapsing bacterial peritonitis.

In CAPD patients with relapsing bacterial peritonitis who do not benefit from intraperitoneal therapy with IgG (IgG nonresponders), the authors demonstrated that peritoneal macrophages are deficient in IgG Fc receptors (FcR) and, therefore, unable to kill bacteria, independent of the levels of the opsonic molecule IgG in the peritoneal dialysis effluent (PDE). Because previous studies showed that interferon-alpha (IFN-alpha) is able to increase in vitro the number of PM0 IgG FcR in CAPD patients with relapsing bacterial peritonitis, the authors studied the in vivo effects of IP administration of IFN-alpha (1,000 IU daily in the overnight exchange for 12 months) on: PM0 superoxide generation; PM0 bacterial killing; PM0 IgG FcR; the number of bacteria in the PM0 cytoplasm; and peritonitis relapses in these patients. By the 10th day, IFN-alpha induced a progressive rise in all of the previously depressed PM0 functions tested, the disappearance of bacteria from the PM0 cytoplasm, and no further episodes of bacterial peritonitis were detected during 12 months. These data indicate that IFN-alpha may represent a useful tool for preventing infections in CAPD patients with relapsing bacterial peritonitis.