Active T rosettes, human autologous T rosettes, OKT8 and OKT4 cells, con A-induced suppressive activity, and autoantibodies: clinical correlations

Lymphocyte subsets in primary sclerosing cholangitis

As an initial step in testing the hypothesis that immunoregulatory abnormalities are important in the pathogenesis of primary sclerosing cholangitis, we determined the number and percentage of lymphocyte subsets in the peripheral blood of 33 patients with primary sclerosing cholangitis. In these patients, when compared with normal and diseased controls, there was a significant reduction in the total number of circulating T cells because of a disproportionate decrease in Leu-2a (suppressor/cytotoxic) cells. This decrease resulted in a significantly increased ratio of Leu-3a to Leu-2a cells. Patients with cirrhosis had significantly higher Leu-3a/Leu-2a (helper/suppressor) ratios than did noncirrhotic patients; both disease groups, however, had ratios that were significantly higher than controls. The number and percentage of B cells were significantly increased. Alterations in the percentage of B cells correlated significantly with histologic stage and concentrations of gamma globulin, serum IgG, and bilirubin. We conclude that these abnormalities are suggestive of a defect in immunoregulation in primary sclerosing cholangitis, which is not secondary to advanced liver disease alone and appears to be independent of chronic ulcerative colitis or obstructive jaundice.

Immunoregulatory effects of fraction 5 thymus peptides. I. Thymosin alpha 1 enhances while thymosin beta 4 suppresses the human autologous and allogeneic mixed lymphocyte reaction

Thymosin alpha 1 and thymosin beta 4, two peptides isolated from preparations of calf thymus fraction 5, were tested in the human mixed lymphocyte reaction (MLR). Thymosin alpha 1 was found capable of enhancing both the allogeneic and autologous MLR. On the contrary, thymosin beta 4 suppressed MLR proliferative responses. Study of the responses of the T cell subpopulations revealed that T4+ (helper/inducer) cells but not T8+ (suppressor/cytotoxic) are responsible for the enhanced, proliferative response to allo- and autoantigens in the presence of thymosin alpha 1. Both the autologous and the allogeneic proliferative responses of either T4+ cells or T8+ cells were not influenced by the addition of thymosin beta 4 in the cultures. However, when T4+ and T8+ subsets were cocultured, thymosin beta 4 was capable of activating T8+ cells to suppress the allogeneic and the autologous proliferative response of T4+ cells. These studies show that thymosin fraction 5 peptides exert immunoregulatory effects on the human MLR proliferative responses in vitro.

The immune system during the pre-cancer and the early cancer period. IL-2 production by PBL from post-menopausal women with and without endometrial carcinoma

We report on alterations in IL-2 production and cell proliferation following PHA stimulation of peripheral blood lymphocytes (PBL) from stage-I endometrial carcinoma (EC) patients, and on mechanisms involved in these alterations. Our study includes 3 groups: EC patients, post-menopausal women at high risk of developing EC, and age-matched healthy women. IL-2 production was markedly lower in most EC patients than in healthy controls. Varying levels of IL-2 were produced by PBL from women in the high-risk group. The proliferative response of PBL to PHA appeared to correlate with levels of IL-2 production. Our results suggest that macrophages are involved, in part, in the modulation of T-cell functions of EC patients.

Regulatory roles of T mu and T gamma cells in the collaborative cellular initiation of the extrinsic coagulation pathway by bacterial lipopolysaccharide

The Shwartzman reaction is a classic biologic response in which the coagulation system is activated in vivo. Cellular initiation of the extrinsic coagulation protease cascade can be mediated by one or more limbs of the lymphoid response to diverse biological stimuli. The T cell-instructed monocyte and macrophage responses that have been implicated are mediated by a number of different cellular pathways and are elicited not only by antigens and allogeneic cells but also by other stimuli such as immune complexes and the lipid A moiety of bacterial lipopolysaccharide (LPS). The latter response has been implicated in the pathogenesis of the disseminated intravascular coagulation associated with bacterial infection. In the rapid collaborative cellular pathway response to LPS, we have described a relatively rigorous requirement for T helper cells in induction of the biosynthesis of tissue factor and Factor VII by monocytes. To elucidate potential regulatory aspects of this cellular procoagulant response, we provide the first evidence for the existence of T suppressor cells for the cellular procoagulant response to LPS by the rapid T cell-instructed pathway. Human peripheral blood lymphocytes were separated by cytoaffinity into Fc gamma-positive and Fc mu-positive cells and were characterized for their functional properties in the procoagulant response. T mu cells mediated the monocyte response, consistent with their identity with instructor cells. T gamma cells suppressed the response of monocytes to LPS in the presence of T mu cells, suggesting that they possess suppressor function for this response. The T gamma suppressor cells required stimulation by LPS to express their suppressor function and they exerted their suppressive effect directly on the monocyte. The existence and participation of LPS-responsive T suppressor cells on the cellular procoagulant response in vitro add a new dimension to the complexity of the rapid pathway of the collaborative cellular procoagulant response and may be important in the pathogenesis of disseminated intravascular coagulation.

Clinical and immunologic response to Isoprinosine in alopecia areata and alopecia universalis: association with autoantibodies

Twenty patients with alopecia universalis, alopecia semiuniversalis and alopecia areata were studied for their immune parameters. Fourteen of them received an oral treatment with Isoprinosine, a synthetic immunomodulator. Ten patients showed the presence of several autoantibodies. No significant abnormalities in various T cell rosette markers were found, but T4/T8 ratios tended to be elevated. Erythrocyte antibody complement (EAC) rosettes were usually decreased. Treatment with Isoprinosine produced a clinical response, as judged by total or partial hair growth, in nine of the fourteen patients treated. It was striking to observe that seven of the nine responders had autoantibodies prior to treatment. These autoantibodies disappeared or decreased with Isoprinosine therapy. In contrast, only one of five nonresponders had serum autoantibodies. After treatment, both groups showed an increase in blood-active T rosettes. These results suggest that alopecia is a heterogeneous disease subdivided by the presence or absence of autoantibodies since clinical response was mainly obtained in patients presenting autoantibodies.

Analysis of T cell subsets in Graves' disease: alterations associated with carbimazole

Conflicting data on subpopulations of peripheral blood lymphocytes in patients with autoimmune disease largely reflect variations in methods of study. An investigation was therefore conducted aimed at avoiding this difficulty. Serial samples of peripheral blood mononuclear cells from 42 patients with hyperthyroid Graves' disease were collected at monthly intervals before, during, and for 12 months after a six month course of carbimazole. Samples were stored in liquid nitrogen until completion of the study, when they were thawed and all samples from each patient analysed within the same assay using mouse monoclonal antibodies to human cell subsets and a fluorescence activated cell sorter. Proportions of cytotoxic/suppressor (OKT8) positive cells before treatment (mean 17.4 (SEM 0.8)%) were significantly lower (p less than 0.001) than those in normal controls (29.8 (1.9)%; n = 10) and returned to normal by the end of treatment. In contrast, the proportions of activated T cells (OKIa-OKM1) were significantly raised before treatment as compared with normal (14.4 (0.6)% versus 4.6 (0.8)%; p less than 0.001) and fell to normal by the end of treatment. Proportions of OKT3 and OKT4 positive T cells remained unchanged throughout treatment and in the succeeding 12 months. In patients who relapsed after treatment there was a rise in the proportion of activated T cells and a fall in OKT8 positive T cells, which returned towards normal with retreatment. The explanation for the alterations in numbers of circulating T cells remains to be determined but they may provide a means for predicting more accurately the outcome of Graves' disease after treatment with carbimazole.

T antigen expression by human lymphocytes in relation to E rosette affinity

Active and late rosette-forming cells, separated on the basis of their different affinities for SRBC, were tested for their ability to react with monoclonal antibodies of the OKT series. No significant preferential distribution of T subpopulations defined by these reagents was found in the high affinity E rosette fraction, while in the low affinity T cell subset the major finding was a high number of cells lacking both OKT4 and OKT8 determinants. This seems to be related to methodology, as indicated by experiments in which sequential cycles of rosetting procedures were found to induce loss of reactivity with OKT monoclonal antibodies. The implications of these methodological observations are further discussed.

[Immune disorders during postoperative peritonitis]

Despite major diagnostic and therapeutic advances, postoperative peritonitis appeared to be still associated with a severe prognosis. The failure to react to delayed hypersensitivity skin tests was recently shown to identify patients at increased risk for sepsis. In an attempt to clarify the mechanisms of this anergy, cellular and humoral immunity was studied with in vitro tests in 12 patients treated for postoperative peritonitis. Complement was decreased in 33.3% of cases and normal in the others. No significant change was found in IgG and IgM titres, but IgA concentrations were increased in 80% of cases. A decrease in the total number of lymphocytes was observed in 41.7% of patients, related to the reduction in the total T lymphocyte count. Mitogen-induced lymphocyte transformation was studied with phytohaemagglutinin, concanavalin A, pokeweed-mitogen, and tuberculin purified protein derivative. Six patients had decreased or negative response to at least three mitogens; 91,7% had no response to tuberculin. The leukocyte migration inhibition test was negative in all cases. These abnormalities in cell mediated immunity may have been related to underlying diseases (severe nutrition depletion in 7 cases), to sepsis (septic shock in 10 cases), to repeated anaesthesias and surgical procedures, and even to drugs (e.g. antibiotics). The presence of serum inhibitors may have been the cause of the anergy and further studies are required.