Lymphocyte populations and cellular immune reactions in vitro in patients with multiple sclerosis

Cell-mediated immunological status in multiple sclerosis patients

In vitro lymphocyte proliferation in response to allogeneic pooled cells, mitogens (PHA, Con A and PWM), and PPD was measured in 67 patients with clinically definite MS and in 67 age and sex-matched controls. Overall, dose-response curves in the two groups were similar, but response to PHA and PWM was significantly greater among patients, and a greater percentage of patients failed to respond to peak and suboptimal PPD concentrations. There was a reduced response to allogeneic pooled cells in Dw2 positive controls, and, in both patients and controls, a tendency towards a higher PPD response in Dw2 positive males. The results suggest that there is some alteration of balance of immune regulation in MS, which is slightly affected by Dw2 status.

Lymphocyte blast transformation responses to mitogens and specific antigens in different clinical phases of multiple sclerosis: a follow-up study

28 MS patients were studied at least 5 times for lymphocyte blast transformation responses to several mitogens (PHA, Con, PWM) and specific antigens (PPD, herpes simplex, measles, mumps, rubella), the mean duration of the follow-up being 15.3 months. Comparison of responses during remissions, exacerbations and ACTH treatment revealed no straight-forward association between the strength of response and clinical disease activity. Mitogen responses did not differ among various disease phases, but the PPD response was significantly lower during exacerbations than during remissions and still lower during ACTH treatment (P less than 0.05, Wilcoxon paired test). In responses to viral antigens, there was the same trend as in the PPD response. However, there were great individual differences in the behaviour of all antigen and mitogen induced lymphocyte responses. As a group, MS patients also showed more changes in their PHA mitogen responses during the follow-up than 8 control subjects followed similarly (P less than 0.005, F-test). The variation coefficient of the PHA response was also correlated with the maximal difference in the Fog neurologic deficit scale during the follow-up time (r = 0.460, P less than 0.05). However, patients with greatest clinical changes most often also received ACTH treatment, which may affect the results. The follow-up results of individual patients revealed that some had quite regular patterns of decreasing responses during disease relapses, whereas others had more irregular wide fluctuations of responses.

Defective production of interferon-alpha associated with HLA-DW2 antigen in stable multiple sclerosis

Interferon (IFN) production by peripheral blood mononuclear cells after induction with one purified and three crude viral antigens was studied in 29 patients with stable multiple sclerosis (MS) and 29 healthy controls. Antiviral substance produced was characterized as interferon-alpha. MS patients produced significantly less IFN-alpha after induction with mumps and purified measles virus antigens and the same tendency was seen after induction with rubella virus antigen. However, when herpes simplex virus antigen was used as the stimulating agent, no difference was seen between MS patients and controls. The decreased ability to produce IFN-alpha was associated with the histocompatibility antigen Dw2. Control subjects positive for Dw2 also produced less IFN-alpha than Dw2-negative controls. In conclusion, we suggest that the observed impaired interferon-alpha production in MS is at least partially due to a high prevalence of Dw2 antigen in this disease.

Defective mitogenic responses in myasthenia gravis and multiple sclerosis

Using in vitro lymphocyte proliferation induced by the phytomitogen concanavalin A (Con A), we investigated immune function and regulation in patients with myasthenia gravis (MG) and multiple sclerosis (MS). Unfractionated peripheral blood mononuclear cells of normal individuals responded to a wide range of ConA concentrations; the T cell fraction responded to a lesser degree and only to high concentrations. These findings suggest the presence of two receptors for ConA, one of high affinity present on a non-T cell accessory cell and the other of low affinity present on T cells. Contrasting defects in the level of response of unfractionated lymphocytes and T cells were found in patients with MG and MS. The peak response of T cells in the MG patients was 22.6 +/- 9.6 X 10(3) cpm (mean +/- SEM) compared with 54.6 +/- 6.5 X 10(3) for controls (p less than 0.05), while the response of unfractionated lymphocytes did not differ from that in controls. For MS patients, the unfractionated lymphocyte response was diminished: 56.3 +/-2.8 X 10(3) cpm versus 70.5 +/- 4.5 X 10(3) for controls (p less than 0.05), while the T cell response was normal. These results indicate a defect in the direct T cell response in MG; in contract, in MS the response requiring T cell-accessory cell interaction is abnormal.

Cell-mediated immunity in multiple sclerosis as determined by sensitivity of different lymphocyte populations to various brain tissue antigens

Peripheral blood lymphocytes from patients with multiple sclerosis (MS) or other neurological diseases and from healthy individuals were separated by density gradient sedimentation into several subfractions. Individual cell populations were cultured in the presence of several human brain tissue antigens. In comparison to controls, mononuclear cells with a density of less than 1.077 gm/cm3 from MS patients displayed a significantly increased sensitivity after incubation with purified human myelin basic protein (MBP) but not with other brain tissue antigens. In particular, the lymphocytes of patients suffering from MS for more than four years reacted positively with MBP, suggesting that the reaction dependent. No difference between MS patients and controls in sensitivity to any brain tissue antigen could be detected with cells of lower density (i.e., 1.073 to 1.069 gm/cm3 or less than 1.069 gm/cm3). Comparable lymphocyte activity was found to antigens isolated from both MS and control brain tissue. These results suggest that patients with chromic progressive MS have a secondary immune activity to MBP.

PPD-, PWM-, and PHA-induced interferon in stable multiple sclerosis: association with HLA-Dw2 antigen and clinical variables

Interferon production after stimulation of lymphocytes with purified protein derivative, pokeweed mitogen, and phytohemagglutinin was studied in 39 patients with stable multiple sclerosis (MS) and 39 age- and sex-matched controls. Stable MS patients produced less interferon, and the number of subjects producing undetectable amounts of interferon was higher in the MS group (11/39) than in the control group (2/39). A tendency toward an association between low interferon production and HLA-Dw2 antigen was found in MS patients. There was no clear-cut correlation between interferon production and the duration of disease or disability of the patients. Although there was no systematic correlation of age with interferon production, patients older than 55 years tended to be very poor interferon producers.

Abnormal regulation of in vitro IgG production in multiple sclerosis

A pokeweed mitogen-stimulated IgG synthesis assay was used to evaluate T suppressor cell function in peripheral blood lymphocytes (PBL) obtained from multiple sclerosis (MS) patients. Autochthonous cultures of fractionated and recombined MS B and T cells exhibited less suppression of IgG synthesis than similar cultures of PBL from control subjects. No difference occurred in the levels of suppression among MS patients grouped according to disease states. When allogenic cultures of MS B and normal T cells or normal B and MS T cells were compared to autochthonous cultures of control cells, no differences were observed. The results suggest that the lower levels of suppression observed in autologous MS cell cultures are not a result of T suppressor cell dysfunction alone.

Lymphocyte blast transformation responses and viral antibodies in relation to HLA antigens in multiple sclerosis

Fifty four clinically stable multiple sclerosis (MS) patients and 54 age- and sex-matched control subjects were HLA-typed, and their responses to herpes simplex, measles, mumps and rubella antigens were examined by the lymphocyte blast transformation test and by serum antibody titrations. Blast transformation response to purified tuberculin (PPD), mitogen phytohaemagglutinin (PHA), pokeweed mitogen (PWN) and concanavalin A (Con A) and spontaneous proliferation of lymphocytes were also studied. MS patients differed from controls by higher antibody levels to measles and rubella viruses and by lower specific blast transformation responses to rubella and measles antigens. When the relative strength of transformation responses was measured, mumps and herpes simplex responses were also lower in MS patients than in controls. In addition, spontaneous lymphocyte proliferation of MS patients in 6-day cultures was lower than that of control lymphocytes. In mitogen stimulations there were no differences between whole groups, but the oldest patients had lower responses to PHA and Con A than their matched controls. The frequency of HLA-Dw2 was 56.6% in MS patients and 32.1% in controls. The patients with and without Dw2 differed from each other only by a lower specific response to PPD in the Dw2-positive group. The immunological response of Dw2-positive controls resembled that of MS patients: low transformation response to viral antigens, low spontaneous proliferation and elevated measles antibodies. This finding supports the function of a genetically determined type of immune responsiveness with low cell-mediated immunity and high levels of certain viral antibodies as one susceptibility factor in multiple sclerosis.

Lymphocyte subpopulations in multiple sclerosis: variations in rosette tests using erythrocytes from different sheep

Lymphocytes from 34 patients with active and with stable multiple sclerosis (MS) were examined by rosetting techniques. Patients with active disease had a relative lymphopenia (35 +/- 9%). When tested with erythrocytes (E) from one out of three sheep used, patients with active MS had a decrease in E-rosette forming cells (E-RFC) compared to patients with stable disease and with healthy controls. Other tests (active E-, EAET-, EA-, and EAC-RFC) did not disclose any differences between patients and controls. The results suggest that the origin of the E may be of importance in E-RFC tests.

Lymphocyte subpopulations in cerebrospinal fluid and peripheral blood in multiple sclerosis

Lymphocytes subpopulations in cerebro-spinal fluid (CSF) and peripheral blood (PB) from multiple sclerosis (MS) patients were studied. PB of MS patients contains the same prevalence of E and EA rosette forming cells compared with controls, consisting of patients affected by various "nonimmunological" neuropsychiatric diseases. Cytochemical identification by the method of acid esterases in PB demonstrated in MS a prevalence of lymphocyte subpopulations similar to controls, and a relatively high percentage of macrophages compared with other methods, especially in MS patients: this may partially account for variable results obtained by various authors with the rosette technique. In CSF a significant decrease of total T, and particularly of T gamma cells, was found. Since T gamma lymphocytes have a suppressor effect on B cell proliferation and Ig synthesis, their decrease could be related with Ig hypersynthesis commonly found in the central nervous system of MS patients.

Lymphocyte transformation in the presence of myelin basic protein in multiple sclerosis and control subjects

The transformation of lymphocytes in vitro in the presence of human myelin basic protein has been investigated in normal people, patients with multiple sclerosis (MS) and controls with other neurological diseases. There was little or no response at low concentrations (1--10 microgram/ml) but significant transformation at higher concentrations (100--1000 microgram/ml) in all three groups. There was no significant difference among the groups as a whole, but those MS patients who had had disease for more than 10 years did show greater responses than normal subjects (P less than 0.05). Increased responses could not be correlated with any other aspect of disease activity: in particular they were not increased in patients with acute relapses. The use of autologous serum instead of homologous AB Rhesus positive serum did not significantly alter lymphocyte responsiveness. The absence of any response in the presence of purified calf thymus histone suggests that the response to myelin basic protein indicates a low level of lymphocyte sensitization to this antigen even in normal subjects. The present evidence does not support a primary pathogenetic role for such a reaction in MS. The increased response in patients with a long duration of disease might merely be an effect of white matter damage or might represent an amplification of the normal immune response contributing to myelin breakdown and leading to the emergence of the progressive stage of the disease. The study of lymphocyte responsiveness over a wide range of concentrations of myelin basic protein is considered to resolve some of the controversy surrounding this subject in the literature.

T lymphocytes in peripheral blood from patients with neurological diseases

Absolute and relative numbers of T lymphocytes in peripheral blood were determined in 19 different groups of patients with neurological diseases, using the E-rosette test. A significantly decreased total number of T lymphocytes was found in the following groups: acute Guillain-Barré syndrome (GBS), active multiple sclerosis (MS), and malignant cerebral tumor. A less pronounced and not significant reduction was observed in patients with amyotrophic lateral sclerosis (ALS). In all other groups of patients normal total numbers of T lymphocytes were found, thus indicating that the decrease in T lymphocyte counts in GBS, MS and malignant cerebral tumors is not due to nonspecific injury of nerve tissue.