Abnormal autologous mixed lymphocyte reaction in autoimmune thrombocytopenic purpura

The autologous mixed lymphocyte reaction (auto-MLR) measures the ability of non-T cells to stimulate autologous T cells to proliferate in tissue culture. The auto-MLR was studied in 11 patients with autoimmune thrombocytopenic purpura (ATP). Seven patients had decreased auto-MLR, which averaged 4440 +/- 3364 cpm (SEM) compared to 15,360 +/- 6905 cpm for simultaneously studied controls. The average of the ratios of cpm incorporated by patients/cpm incorporated by control subjects was 0.20 +/- 0.06 (p less than 0.01). Serum from all 7 patients with low auto-MLR decreased the auto-MLR of normal subjects by an average of 56% +/- 8.5 (p less than 0.001). Preliminary results indicate that the inhibitory effect was mediated by a component of the IgG immunoglobulin fraction of serum. Sera from normal persons and from ATP patients with normal or high auto-MLR did not affect the auto-MLR of normal subjects. It was further shown that non-T cells from 3 of 5 patients with decreased auto-MLR failed to stimulate allogeneic T cells normally. It is concluded that many patients with ATP have decreased auto-MLR apparently due to the presence of a serum blocking factor and, perhaps, a defective stimulatory capacity of non-T-cells.

Abnormal autologous mixed lymphocyte reaction in autoimmune thrombocytopenic purpura

The autologous mixed lymphocyte reaction (auto-MLR) measures the ability of non-T cells to stimulate autologous T cells to proliferate in tissue culture. The auto-MLR was studied in 11 patients with autoimmune thrombocytopenic purpura (ATP). Seven patients had decreased auto-MLR, which averaged 4440 +/- 3364 cpm (SEM) compared to 15,360 +/- 6905 cpm for simultaneously studied controls. The average of the ratios of cpm incorporated by patients/cpm incorporated by control subjects was 0.20 +/- 0.06 (p less than 0.01). Serum from all 7 patients with low auto-MLR decreased the auto-MLR of normal subjects by an average of 56% +/- 8.5 (p less than 0.001). Preliminary results indicate that the inhibitory effect was mediated by a component of the IgG immunoglobulin fraction of serum. Sera from normal persons and from ATP patients with normal or high auto-MLR did not affect the auto-MLR of normal subjects. It was further shown that non-T cells from 3 of 5 patients with decreased auto-MLR failed to stimulate allogeneic T cells normally. It is concluded that many patients with ATP have decreased auto-MLR apparently due to the presence of a serum blocking factor and, perhaps, a defective stimulatory capacity of non-T-cells.

Influence of Splenectomy upon Immunologic Reactivity of Patients with Hodgkin'S Disease

Since most patients with Hodgkin's disease benefit from splenectomy, a study was designed to explore whether these beneficial effects could be attributed to the recovery of patients’ immunologic reactivity. Using a series of ordinary skin test (PPD-tuberculine, Varidase and Candidin) determination of absolute T and B lymphocyte counts in peripheral blood and their mitogenic responsiveness, assessment of immunologic reactivity was performed in 28 Hodgkin's disease patients, prior to and 14 days after splenectomy. The results showed that overall immunologic reactivity of these patients was suppressed as judged by low absolute lymphocyte counts (1747.2 ± 171.9), lower counts of T (592.0 ± 92.1) and B cells (295.9 ± 40.5) and their poor capacity to respond to phytohemagglutinin (PHA) (20342.6 ± 3662.8 cpm), although the reactivity towards skin test antigens seemed to be well preserved. After splenectomy the reactivity improved, absolute lymphocyte counts raisd to 2654.9 ± 468.8 and were parallelled by an increase in T (936.7 ± 138.0) and B cell counts (402.2 ± 81.2). PHA reactivity recovered as well (26965.5 ± 4035.6 cpm), however, its remained lower than in control cultures. Furthermore, the immunocompetence of patients’ spleens was assessed. The possible influence of some suppressive mechanisms such as serum-blocking factor and prostaglandins is discussed.