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

Increased B cell and cytotoxic NK cell proportions and increased T cell responsiveness in blood of natalizumab-treated multiple sclerosis patients

Background

Changes in the blood lymphocyte composition probably both mediate and reflect the effects of natalizumab treatment in multiple sclerosis, with implications for treatment benefits and risks.

Methods

A broad panel of markers for lymphocyte populations, including states of activation and co-stimulation, as well as functional T cell responses to recall antigens and mitogens, were assessed by flow cytometry in 40 patients with relapsing multiple sclerosis before and after one-year natalizumab treatment.

Results

Absolute numbers of all major lymphocyte populations increased after treatment, most markedly for NK and B cells. The fraction of both memory and presumed regulatory B cell subsets increased, as did CD3^-CD56^dim cytotoxic NK cells, whereas CD3^-CD56^bright regulatory NK cells decreased. The increase in cell numbers was further associated with a restored T cell responsiveness to recall antigens and mitogens in functional assays.

Conclusions

Our data confirms that natalizumab treatment increases the number of lymphocytes in blood, likely mirroring the expression of VLA-4 being highest on NK and B cells. This finding supports reduction of lymphocyte extravasation as a main mode of action, although the differential effects on subpopulation composition suggests that cell-signalling may also be affected. The systemic increase in T cell responsiveness reflects the increase in numbers, and while augmenting anti-infectious responses systemically, localized responses may become correspondingly decreased.

HLA class II associated risk and protection against multiple sclerosis-a Finnish family study

We analyzed the HLA class II haplotypes in 249 Finnish nuclear families and compared the frequencies of parental haplotypes transmitted or non-transmitted to multiple sclerosis (MS) patients. The most important predisposing haplotype was DRB1*15-DQB1*0602 (P<10(-6)) as expected and a weak predisposing effect of DRB1*04-DQB1*0302 was revealed after the elimination of DRB1*15-DQB1*0602. HLA-DRB1*01-DQB1*0501 and DRB1*13-DQB1*0603 were negatively associated with MS in transmission disequilibrium test, but only the DRB1*13-DQB1*0603 association remained significant (P=0.008) after the elimination of DRB1*15-DQB1*0602 haplotypes. Based on this study HLA class II haplotypes exhibit both predisposing and protective effects in MS.

Radioimmunoprecipitation and immunoblot studies of antibodies to rubella virus in patients with chronic liver disease

Patients with autoimmune chronic active hepatitis (AICAH) and some other chronic liver disorders often have very high titres of rubella HI antibodies. In the present study sera from 46 patients with chronic liver disease and controls were examined for rubella antibodies using radioimmunoprecipitation assay (RIPA) and Western blot. RIPA appeared to be more suitable than Western blot for the study of the individual antibody specificities provided that proteins (possibly actin) interfering with the resolution of the E2 glycoprotein band are identified. It was shown that patients with high rubella HI titres reacted strongly against the E1 glycoprotein and in general also against the core protein (C). Reactivity to the E2 glycoprotein was detected with all sera from patients with chronic liver disease but varied more in strength. Three patients with post-acute rubella showed very faint E2 reactivity, but strong E1 and C reactivities. Patients with primary biliary cirrhosis had normal HI titres and showed no increase in reactivity in RIPA. The present findings show that patients with chronic liver disease and high rubella HI antibody titres exhibit an enhanced specific antibody response to rubella virus structural proteins.

Antibody response to rubella virus structural proteins in multiple sclerosis

The antibody response to the structural proteins of rubella virus was studied in patients with multiple sclerosis (MS). Irrespective of the antibody titer to whole rubella virus, the relative proportion of the IgG response to the surface glycoprotein E1 was diminished, and that to the surface glycoprotein E2 was elevated in MS patients when compared to a matched control population of normal health individuals or a group of patients with systemic lupus erythematosus and other collagen vascular diseases. No difference was observed in the response to the core protein of rubella virus on comparing the MS and normal control groups. This divergence in the relative antibody response to the viral surface proteins suggests that the vigorous antibody response to rubella virus reported in MS is not simply an expression of a nonspecific polyvalent B-cell response.

Antibody response to different antigenic sites on measles virus surface polypeptides in patients with multiple sclerosis

Antibodies to different antigenic sites on measles virus (MV) surface proteins were examined in sera from 34 HLA-typed age- and sex-matched pairs of multiple sclerosis (MS) patients and control subjects by a previously developed competitive enzyme immunoassay in which human sera and monoclonal MV-specific antibodies compete for binding to the same antigen. Antibodies specific to 4 partly overlapping sites on the haemagglutinin protein and two sites on the fusion protein of MV were measured in addition to previously determined total antibody titres and antibody levels were compared between groups. MS patients had significantly higher levels of antibodies in six out of seven comparisons. Both the MS and the control group were further divided to subgroups with HLA-Dw2, -Dw1, -A2, -A3 and -B7 histocompatibility antigens and MV antibody levels in these groups were compared. The presence of the HLA-A2 or -A3 antigen did not have a significant effect on the antibody levels but both the HLA-Dw2 and -B7 antigens were associated with elevated antibody levels to antigenic sites defined by monoclonal antibodies. This was also supported by higher frequencies of these alleles in subgroups with high antibody titre both in MS patients and controls. Moreover, presence of Dw1 antigen was associated with lower mean titres especially against the fusion protein in control patients. The findings indicate that HLA antigens can control immune response to separate sites on a protein antigen either directly as immune response genes or through linkage to other genes.

Effect of cyclosporine on rubella virus-specific immune responses in chronic progressive multiple sclerosis

Cyclosporine A (CsA) has been used in putative autoimmune diseases after sensitization to unknown antigens. We have previously shown that CsA prevented continued activation of T-cells in chronic progressive multiple sclerosis (CPMS) patients. The current study was undertaken to determine whether CsA, or CsA and prednisone (CsA + P) could suppress immune responses to a common recall antigen. Serum antibody levels were higher in all CPMS patients than age-matched normal controls. However, rubella antibody titers in the CsA or CsA + P groups were no different from a placebo-treated CPMS patient group. The lymphocyte responses to inactivated rubella virus of CsA and CsA + P-treated CPMS patients were lower than placebo and control but not statistically different. Therapy with both CSA and CSA + P was associated with significantly lower panel mixed leukocyte responses and Ta1 expression than in the placebo-treated group; CD3, CD4, CD8 antigen expression and active rosette formation by T-cells were similar for the three CPMS groups. These results suggest that while CsA exerts measurable effects on non-specific indicators of cellular immunity in CPMS patients, it may not be as effective in suppressing pre-existent specific immune responses.

NK activity and NK-like non-specific cytolysis after PPD, rubella and measles antigen stimulation in multiple sclerosis

Blood samples were collected from 14 pairs of multiple sclerosis (MS) patients and from age- and sex-matched healthy controls. The cytotoxic activity of peripheral blood mononuclear cells was tested against the K562 cell line on the day of collection and again after 3 days in vitro culture with medium or with purified protein derivative of tuberculin (PPD), inactivated rubella virus or inactivated measles virus antigen. Lymphocytes from MS patients had a lower spontaneous cytotoxic activity compared to the controls both on the day of collection (P less than 0.025) and after 3 days in culture with medium alone (P less than 0.025). The activity decreased during in vitro culture in both groups, but the decrease was greater among MS patients (P less than 0.05). In cultures with antigens, a strong increase of NK-like cell-mediated cytolysis (NK-like CMC) was noted especially in cultures stimulated with PPD. There were no significant differences in the increase of the activity among MS patients and control subjects. A significant correlation between the increase of NK-like CMC and the lymphocyte blast transformation response induced by each antigen was found.

Comparison of HLA-Dw1 and -Dw2 positive adherent cells in antigen presentation to heterozygous T-cell lines: a low rubella antigen-specific response associated with HLA-Dw2

T-cell lines specific for purified tuberculin (PPD), rubella, and herpes simplex virus (HSV) antigens were established from two Dw1/w2 heterozygous subjects. Fresh peripheral blood monocytes from healthy individuals with shared and non-shared D-antigens were used as presenting cells and the T-cell lines as responders in lymphocyte blast transformation assays with specific antigens. An HLA-restricted reaction was seen with all the antigens, although the PPD- and HSV-specific cell lines reacted stronger than rubella-specific lines when the specific antigens were presented by monocytes not sharing the D-antigens. A significantly lower response was seen when rubella antigen was presented by Dw2 positive monocytes as compared to response promoted by Dw1 positive monocytes (p less than 0.0001, Mann-Whitney U-test), whereas no such difference was seen in responses to PPD or herpes simplex antigen.

Immune functions in healthy blood donors with HLA-DW2 and -DW3 antigens

We compared healthy blood donors with and without HLA-Dw2 and -Dw3 in immunity assays, the results of which have been found to be abnormal in multiple sclerosis or autoimmune diseases. Tests included lymphocyte blast transformation responses to rubella, mumps and purified tuberculin (PPD), in vitro production of IgG and interferons, natural killer (NK) cell function and measurement of serum antibodies to measles, rubella, mumps and herpes simplex viruses. HLA-Dw2-positive subjects had a lower lymphocyte blast transformation response to rubella virus antigen and a lower NK cell function compared with HLA-Dw2-negative subjects. The presence of HLA-Dw3 was associated with an increased spontaneous and mumps virus-induced immunoglobulin production. No significant differences were found in other assays. These results support the existence of HLA-Dw2- and Dw3-associated deviation of immune responsiveness, which may contribute to the susceptibility of multiple sclerosis or other autoimmune type diseases.

Evidence of an accelerated B-cell destruction in HLA-Dw3/Dw4 heterozygous children with type 1 (insulin-dependent) diabetes

The possible association between residual B-cell function and specific HLA antigens in Type 1 (insulin-dependent) diabetes was studied in a cross-sectional series of 144 diabetic children and adolescents, as well as in a prospective series of 44 newly diagnosed diabetic subjects who were observed for the initial 2 years of their diabetes. In the cross-sectional study, the HLA-Dw3/Dw4 heterozygotes had a lower mean serum C-peptide concentration during 1980, 0.03 +/- 0.01 nmol/l (mean +/- SEM) vs. 0.09 +/- 0.01 nmol/l (p less than 0.02), as well as a lower 24-h urinary C-peptide excretion, 0.27 +/- 0.06 nmol/m2 vs. 1.34 +/- 0.19 nmol/m2 (p less than 0.05), than the other subjects. In addition, the Dw3/Dw4 heterozygotes had a clinical remission of shorter duration, 113 +/- 47 days vs. 203 +/- 22 days (p less than 0.05), and a higher mean glycosylated haemoglobin level during 1980, 14.8 +/- 0.05% vs. 13.7 +/- 0.2% (p less than 0.05), than those without the Dw3/Dw4 combination. In the prospective study the serum C-peptide concentrations were of the same magnitude in the Dw3/Dw4 heterozygotes and the other subjects during the first month. Subsequently the C-peptide concentrations in the subjects with the Dw3/Dw4 combination started to decrease 2 months earlier than in the other subjects. The Dw3/Dw4 children had a significantly lower serum C-peptide concentration at 21 months, 0.01 +/- 0.01 nmol/l vs. 0.13 +/- 0.02 nmol/l (p less than 0.01), and at 24 months, 0.03 +/- 0.01 nmol/l vs. 0.12 +/- 0.02 nmol/l (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Abnormalities of serum and plasma components in patients with multiple sclerosis

Qualitative and quantitative abnormalities in protein and non-protein components of serum and plasma in patients with multiple sclerosis have been the subjects of numerous reports. In this review many of the more recent observations are documented and evaluated. It is concluded that at present the welter of information that has been gathered does not contribute in any major, coherent way to our understanding of the etiology or pathogenesis of the disorder. Several of the abnormalities that have been observed may be future candidates for biochemical markers for multiple sclerosis; at present none is sufficiently reliable, distinctive or easily performed to warrant the status of a useful diagnostic or prognostic test.

The production of interleukin 2 as a measure of reactivity in mixed lymphocyte culture

Interleukin 2 (IL2) produced in vitro in mixed lymphocyte cultures was measured by induction of growth in cells dependent on IL2 for proliferation. The amount of IL2 in early cultures (24 and 48 hours) clearly differentiated the degree of HLA-D locus identity between various individuals. Very low amounts of IL2 were produced in cultures between HLA-D identical subjects. The use of IL2 measurement offers a method in the early culture phase for predicting the T cell proliferation which is dependent on the presence of IL2.

Immunity in herpes gestationis: inhibition of mixed lymphocyte culture by patients' sera

The families of four patients with herpes gestationis (HG) (pemphigoid gestationis) and five patients with polymorphic eruption of pregnancy (PEP) were HLA typed. Anti-HLA-D antibodies in the maternal sera were sought using mixed lymphocyte culture (MLC) inhibition test. Two of the four patients with HG had Dw3, one of which was combined with Dw4. One of the fathers had Dw2. The sera of the four patients with HG strongly inhibited (48-100%) the MLC reaction of maternal cells against cells of the father or the child. This kind of inhibition could not be shown in the patients with PEP. We conclude that patients with HG often seem to have MLC inhibiting factors which obviously are antibodies directed against HLA-D region determinants. Their pathogenic role is still obscure.

Histocompatibility antigens in familial multiple sclerosis in a high-risk area of the disease

Fourteen Finnish families, each with two or more cases of multiple sclerosis (MS), were analysed for HLA antigens. Seventy family members were studied. They were all born in a high-risk area of MS and came from families with an unusually high frequency of MS. The frequencies of B7, B12 and DR2 were increased both in patients and their healthy relatives, whereas A1, B8 and DR1 were decreased in patients. MS patients shared the HLA haplotypes more often than expected.

HLA-Dw1 and BfF as protective markers in multiple sclerosis

The frequencies of Properdin factor B allotypes were studied in 54 multiple sclerosis patients and 58 healthy control subjects, and the association of various phenotypes with HLA-Dw1 and Dw2 antigens (found with decreased and increased frequency in MS patients, respectively) was further studied. SS genotype was found in 76% of MS patients and 63% of control subjects (n.s.) F types (FS + FF) were found to be strongly associated with HLA-Dw1 in control subjects (P less than 0.0014), whereas neither SS nor F containing types were associated with Dw2. The findings support the concept of a hypothetical MS resistance factor in the HLA gene area.

Immune responses to live attenuated and inactivated mumps virus vaccines in seronegative and seropositive young adult males

Live attenuated mumps virus vaccine and Formalin-inactivated mumps vaccine were compared for their ability to induce antibody responses and cell-mediated immune responses as measured by a lymphocyte blast transformation test (LBT). The subjects studied were conscripts of the Finnish Defense Forces. In seronegative subjects antibody levels induced by attenuated virus were more variable than those induced by inactivated virus, including one failure with the live vaccine out of a total of nine subjects. IgM antibody class response was seen only in four of nine subjects vaccinated with live virus--in those subjects with the highest post-vaccination antibody levels and strongest LBT responses. Increases of antibody levels in originally seropositive subjects were higher in subjects vaccinated with inactivated virus. Cell-mediated immunity induced by both vaccines was relatively poor when measured by the LBT test. At a time of 6-8 months after vaccination, LBT responses in originally seronegative subjects were not observed.

HLA antigens in rubella seronegative young adults

HLA antigen frequencies, including those of five HLA-D specificities, were studied in 91 rubella seronegative subjects who were found in screening programs for rubella vaccination. No significant differences in antigen frequencies between rubella seronegative subjects and the reference population could be found.

Interferon production and natural killer (NK) activity in leukocyte cultures from multiple sclerosis patients

Peripheral blood leukocyte (PBL) cultures from only 37% of MS patients produced detectable HuIFN-gamma in response to ConA as opposed to 85% of the cultures derived from normal blood donors. However, the yields in patient-derived cultures that were responsive, were not lower than those in cultures from controls. Production of HuIFN-alpha after stimulation with Sendai virus was not aberrant in cells taken from MS patients. The difference in HuIFN-gamma response rate between MS and normal donor-derived cells was more pronounced when DR2+ carriers were compared amongst each other than when DR2-k carriers were compared. Among the MS patients, the failure of PBLs to produce HuIFN-gamma in response to ConA was not correlated with age, sex, disease duration and type of disease. However, positive correlations were found with current disability indices and past disease progression rates. Unstimulated NK-activities of MS patient-derived PBLs were not different from those of normal donor-derived cells. the degree of augmentation of the activity by stimulation with ConA and interferon-alpha was also normal. Within the MS patients group, but not in the control group, there was a trend for DR2+ carriers to have lower spontaneous and stimulated NK-activities than DR2- individuals.

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.

Immune complexes in serum and cerebrospinal fluid of multiple sclerosis patients and patients with other neurological diseases

Paired serum and cerebrospinal fluid (CSF) specimens from 30 multiple sclerosis (MS) patients and 30 patients with other neurological diseases (ONDs) were analyzed for the presence of immune complexes (ICs). With each of the 4 tests used, ICs were found more frequently in sera from both MS and OND patients than in sera from healthy blood donors. IC-positivity for MS and OND patient CSF varied from 10-33% and from 10-17% in different tests. The number of IC-positive sera or CSF in MS patients did not differ significantly from those in OND patients. For both MS and OND patients, the positivity pattern for serum and CSF specimens in each IC test was essentially unique. Furthermore, because several CSF IC-positive and serum IC-negative paired specimens were found, intrathecal IC formation may be independent of IC formation in peripheral blood. The presence of ICs in serum or CSF did not correlate with the clinical status of or laboratory data on the MS patients, nor was a correlation found with the diagnosis of the OND patients. In total, these results suggest that the presence or absence of ICs in MS or OND patients may simply reflect changes in the immunological regulation of individual patients.

Virus antibodies in Parkinson's disease. Herpes simplex and measles virus antibodies in serum and CSF and their relation to HLA types

Serum and cerebrospinal fluid (CFS) immunoglobulin G (IgG) antibodies to herpes simplex (HSV) and measles viruses were assayed with a radioimmunoassay in 56 patients with idiopathic Parkinson's disease and in a similar number of age- and sex-matched controls with other neurological diseases. As a group, the patients with Parkinson's disease had a significantly increased serum antibody level against HSV, but measles virus antibody levels were similar in both groups. Both in the Parkinson's group and in the control group, the levels of the total IgG in CSF were within normal limits and the CSF antibodies to HSV and measles virus paralleled the serum antibody titers relative to the total IgG serum-to-CSF ratios. This indicates no increased intrathecal antibody production in either group. In 48 patients with Parkinson's disease who were HLA-typed, no association of viral antibody levels with particular HLS antigens were noted. The findings suggest that HSV is not present within the central nervous system of the patients with Parkinson's disease. The increase HSV antibody level seen in Parkinson's disease patients may reflect a more general disturbance of the patients' immune functions.

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.