INCREASED MUSCARINIC CHOLINERGIC RECEPTOR DENSITY ON CD4+ LYMPHOCYTES IN PROGRESSIVE MULTIPLE-SCLEROSIS

We measured the density and affinity of muscarinic cholinergic receptors (MR) in 29 chronic progressive and ten stable multiple sclerosis (MS) patients and 27 control subjects using [3H]N-methyl-scopolamine. The density of MR on CD4+ lymphocytes was significantly higher in chronic progressive MS (CPMS) than in controls (7.9 +/- 0.7 vs. 4.5 +/- 0.4 fmol/10(6) cells, p < 0.001). Stable patients did not differ significantly from control subjects. Receptors of the MI subtype were measured on CD4+ lymphocytes of nine patients and seven controls with the selective antagonist [3H]methylpirenzepine: M1/total receptor ratio was 64.1% in CPMS and 81.2% in controls, suggesting a selective increase of M2-type MR in CPMS. The findings may relate to parasympathetic denervation hypersensitivity of lymphocytes or to lymphocyte activation which is known to be associated with increased MR number.