Morphological and functional findings of fixed phagocytes in psoriatics.

Twenty-one psoriatics as well as 24 normal healthy adults were studied by functional bone marrow scintigraphy using Tc-99m-labeled human serum albumin millimicrospheres (Tc-99m-HSA-MM). Functional bone marrow scintigraphy is an in vivo test system for the assessment of various functional properties of fixed phagocytes. Of psoriatics who had no systemic drug treatment, 59% demonstrated peripheral extension of the bone marrow space, indicating hyperplasia of bone marrow phagocytes. This phenomenon could be observed only in one normal subject who was a high-performance sportsman. Of psoriatics treated with aromatic retinoid, 83% (n = 6) demonstrated bone marrow extension, as did 100% (n = 3) of psoriatics with cirrhosis of liver. The "capacity' of bone marrow phagocytes to engulf Tc-99m-HSA-MM ("uptake ratio') was diminished in 34% of nontreated as well as 66% of psoriatics treated with aromatic retinoid. The phagocytic and proteolytic turnover of Tc-99m-HSA-MM in the bone marrow, spleen, and liver was found to e accelerated in 66% of nontreated psoriatics, normal (83%) or accelerated (17%) in psoriatics treated with aromatic retinoid, and considerably delayed in all of the psoriatics with cirrhosis of liver. Functional bone marrow scintigraphy proved to be an appropriate in vivo test system for revealing abnormalities of fixed phagocytes in psoriatics. Furthermore, therapeutic effects as well as the influences of preexisting disorders on different phagocyte populations can be assessed.