Significant enhanced superoxide anion (O2-) production in vitro by peripheral blood monocytes of lepromatous leprosy patients stimulated with liposome and suppression by C-reactive protein (CRP).

Peripheral blood monocytes (PBM) from normal individuals, infectious mononucleosis (IM) and leprosy patients were stimulated with liposome. The mean and standard error of superoxide anion (O2-) generated in nm/1.5 X 10(5) PBM/well for 5 normal subjects and 3 IM patients was 2.9 +/- 0.5 and 3.1 +/- 0.2, respectively. Monocytes stimulated with 100 ng C-reactive protein (CRP) incorporated into liposome gave values of 3.3 +/- 0.3 and 2.7 +/- 0.1 nm O-2/1.5 X 10(5) PBM/well for normals and IM, respectively. No significant differences in O2- production between liposome and liposome with incorporated CRP were shown. PBM from lepromatous patients demonstrated a significant (p less than 0.01) increase in O2- production with liposome alone compared with tuberculoid patients (3.5 +/- 0.4 vs 1.8 +/- 0.3). The most dramatic suppression of O2- shown when purified CRP was added to the mixtures in all groups examined [0.4 +/- 0.1 (500 ng), 0.3 +/- 0.0 (500 ng), 1.5 +/- 0.1 (100 ng), and 1.3 +/- 0.6 (100 ng) nm O2-/1.5 X 10(5) PBM/well for normals, IM, lepromatous, and tuberculoid, respectively]. Results of O2- formation with incorporation of CRP into liposome as compared with liposome alone had no significant effect on PBM of lepromatous or tuberculoid patients. It is suggested that CRP may play a significant role in regulation of oxygen free radicals formed during acute and chronic inflammatory episides.