Macrophage migration inhibitory activity in the sera of patients undergoing peritoneal dialysis for psoriasis.

A study of macrophage migration inhibitory activity (MIA) in serum was carried out in four psoriatic patients with normal renal function who were undergoing peritoneal dialysis (PD) as a method of therapy. Before weekly PD treatment, the MIA was negative in these patients. whereas immediately thereafter it was positive. In two of these patients the appearance of MIA paralleled the clinical improvement observed. The increase in MIA observed after each PD was of short duration, usually being followed by a subsequent decrease prior to the next PD. Seven uremic patients who were similarly studied for the presence of MIA before and after PD did not show this pattern of response. It is suggested that the appearance of MIA in psoriatic patients undergoing PD as a method of therapy reflects the extraction of a "dialysable serum factor", which may be associated with cell-mediated immunity as well as with the clearing of skin lesions observed in these patients.