Myasthenia gravis: studies on HL-A antigens and lymphocyte subpopulations in patients with myasthenia gravis.

Thirth-three patient with a clinical diagnosis of myasthenia gravis were tissue-typed for HL-A antigens. In agreement with earlier reports a significant increase in antigens HL-A1 and HL-A8 were found in this material. Two of the patients were treated with chronic thoracic duct drainage. Proportions of T and B lymphocytes in lymph and peripheral blood were estimated in these patients. In the lymph an initial decrease in the proportion of T cells occurred, which was accompanied by a subsequent increase in the proportion of B cells. Towards the end of the chronic drainage period this effect was reversed. A slightly different picture occurred in blood lymphocytes. Initially, there was an increase in both T and B cells, followed by a decrease in T-cells numbers in one patient, whereas in the second patient the proportion of T cells decreased from the onset of drainage while the proportion of B cells steadily increased. These studies showed that available markers for determination of T ANd B cells were useful for studies of lymphocyte subpopulations in blood and lymph. Lmyphocytes from the thoracic duct were also tested for their reactivity to various mitogens specific for either T or B cells. The B-cell mitogens which were used were dextran sulphate, lipopolysaccharide, purified protein derivative, as well as rabbit anti-human beta2-microglobulin serum. The T-cell mitogens investigated were concanavalin A and phytohaemagglutinin. No significant differences in the responsiveness of thoracic duct lymphocytes compared to normal peripheral blood lymphocytes were found.