Abstract
Cell electrophoresis identifies two main subpopulations of blood polymorphonuclear cells (PMNs), which in terms of the speed of their anodic migration are referred to as the fast and slow population. When blood PMNs from normal healthy subjects were incubated in medium containing 20% RA serum there was a decrease in the percentage of fast cells with a corresponding increase in the slow population that was directly related to the levels of circulating immune complexes present in the sera. Similar results were obtained when using heat induced aggregated human IgG (HAGG) or Candida albicans instead of RA serum. The 'slowing' effect of HAGG, which was transient and time dependent, appeared to be due to its internalisation by the PMNs. These results suggest that in RA the large number of blood PMNs with a low surface charge (i.e., the slow population) may arise as a result of the constant interaction of these cells with circulating immune complexes.