Inhibitory effect of sera from rheumatoid arthritis patients and enhancing effect of levamisole on total E-rosette levels of lymphoid cells from normal and RA subjects

: We determined the E-rosette levels (E-R) in rheumatoid arthritis patients (RA) and repeatedly tested a selected group with depressed E-R. We also evaluated, in vitro, the inhibitory effect of RA sera on normal E-R and the enhancing effect of levamisole (LV) on normal and RA E-R. Selection criteria and E-R protocol were those of Di Perri (1979). Mononuclear cells (MNC) from 23 normal donors had a mean E-R of 53 +/- 7% (X +/- SD) and this was unchanged after incubation with 32 microM LV. MNC from 31 RA displayed a value of 42 +/- 7% which was lower (p = 0.01) than the normal values and which increased to 47 +/- 9% after LV treatment (p = 0.02). Twenty of these RA did not show enhanced E-R after LV; the remaining 11 RA had E-R of 37 +/- 6% which were restored to 50 +/- 8% after incubation with LV (p = 0.001). We defined this latter group of RA as depressed responders (DR). Four DR were tested repeatedly over a four-month period and consistently remained depressed. Their sera had inhibitory activity on E-R of healthy donors. In vitro treatment of healthy MNC with these RA sera plus 3.2 microns LV abrogated the inhibitory effect. Both the IgG and the IgM fractions of the RA sera manifested this inhibitory effect. We conclude that RA can have depressed E-R which are not transient and can be corrected by in vitro incubation with an immunomodulator. Sera from these RA can inhibit E-R of normal MNC, and LV can abrogate the inhibitory activity of such sera.