Increased EA-rosette formation by lymphocytes from patients with rheumatoid arthritis.

A modified method for estimating erythrocyte-antibody (EA) rosette formation of human peripheral blood lymphocytes (PBL) reveals consistent differences between rheumatoid arthritis (RA) patients tested and healthy control subjects. Using this method we find an average of 27 +/- 0-8% (standard error of mean) of PBL from 120 RA patients forming EA rosettes in contrast to only 6 +/- 0-6% of PBL from ninety-five healthy controls, and 7 +/- 0-9% from eighteen patients with systemic lupus erythematosus (SLE). This difference is not due to monocytes forming EA rosettes or to T-cell sheep red blood cell (SRBC) binding. The concentration of antibody used in our assay appears to highlight the RA-control differences--suggesting a possible qualitative difference in EA-binding capacity. We find no correlation between EA binding and disease duration or rheumatoid factor titre. The assay is susceptible to technical variation, and the effects of antibody concentration, lymphocyte to SRBC ratio, method of blood collection and lymphocyte-separation procedure have all been evaluated.

Fc receptors on lymphocytes from the blood of rheumatoid arthritis patients and normal controls: a comparison of four Fc receptor assays.

Peripheral blood lymphocytes (PBL) from rheumatoid arthritis (RA) patients and healthy controls (NC) were assayed for Fc receptors by four methods. Three of the four assays showed RA PBL to contain a greater proportion and number of Fc receptor-bearing cells than PBL from healthy controls. This confirmed our earlier report and indicated that the proportion of Fc receptor-bearing cells detected can be influenced by the test system. Neither the proportion of B, nor the non-B, non-T lymphocytes was consistently increased in RA PBL, suggesting that the increase found results from an increase in Fc gamma receptor-positive T cells.