Intravenous immunoglobulin modulates lymphocyte CD54 and monocyte FcgammaRII expression in patients with chronic inflammatory neuropathies.

We studied the expression of different lymphocyte and monocyte cellular determinants involved in leukodiapedesis and antigen presentation in 10 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN) with persistent conduction blocks before intravenous immunoglobulin (IVIg), immediately after infusion of IVIg and 1 week after infusion. We observed a decrease of T lymphocytes expressing ICAM-1 (CD54) immediately after infusion in 8 out of 10 patients (p<0.04) with a return to pretreatment values after 1 week. The monocytes showed an increase in CD14(+) cells and CD14(+) FcgammaRII inhibitory receptor positive cells, no change in the number of CD14(+) FcgammaRIII activation receptor cells, and an increase in the FcgammaRII/FcgammaRIII ratio on monocytes 1 week after IVIg. Thus, the mechanism of action of IVIg in both CIDP and MMN may involve inhibition of T cell transmigration and modulation of antigen presentation capacities through FcgammaR expression.