Changes in lymphocyte subsets during the course of experimental allergic neuritis.

The percentages of various leucocyte subsets in the blood, spleen and popliteal lymph nodes of animals with experimental allergic neuritis (EAN) were determined at various times between the initiation of the disease and recovery. The total cell yield from these tissues and the weights of the spleens and lymph nodes were recorded. Clinical and histological signs of disease were assessed at the same time points. Normal and adjuvant control animals were also studied. The most marked change observed was that the percentage of MRC OX 8+ ('suppressor/cytotoxic') cells in the blood of animals with EAN was significantly below the normal value during the most severe clinical disease, and then returned to normal during recovery. Adjuvant controls did not show this change. No significant differences were observed in the other lymphocyte subsets studied (surface Ig+, Ia+, W3.13+ and W3.25+ cells) or in the total white cell count in the blood. There were no changes from normal values in any of the parameters examined in the spleen. The popliteal lymph nodes were enlarged in both adjuvant controls and animals with EAN and both showed a decrease in the percentage of W3.25+ lymphocytes from normal unenlarged nodes.