Distribution of HLA-SB antigens in multiple sclerosis

Genetics of multiple sclerosis--how could disease-associated HLA-types contribute to pathogenesis?

Multiple sclerosis is a chronic demyelinating disease of the central nervous system in young adults. It is considered a T cell-mediated autoimmune disease which is probably triggered by exogenous events, e.g. infectious agents, in susceptible individuals. Population, family and twin studies indicate that genetic factors and most likely several genes are associated with disease, but it is clear from the concordance rates of identical twins (25-30%) that genetic background as well as exogenous or somatic events are required to develop disease. Among many candidate genes which have been analyzed during recent years, the strongest association was shown for genes of the HLA-class II complex, in particular HLA-DR15 Dw2 and -DQw6. At present, it is not clear how the expression of a particular HLA-class II gene translates into susceptibility to develop an organ-specific autoimmune disease. Potential explanations how this could occur will be discussed.

Immunological aspects of experimental allergic encephalomyelitis and multiple sclerosis

Multiple sclerosis (MS) is the most frequent, demyelinating disease of the central nervous system (CNS) in Northern Europeans and North Americans. Despite intensive research its etiology is still unknown, but a T cell-mediated autoimmune pathogenesis is likely to be responsible for the demyelination. This hypothesis is based both on findings in MS patients and studies of an experimental animal model for demyelinating diseases, experimental allergic encephalomyelitis (EAE). Experiments in EAE have not only demonstrated which myelin antigens are able to induce the demyelinating process but also have determined the characteristics of encephalitogenic T cells, that is, their fine specificity, major histocompatibility complex (MHC) restriction, lymphokine secretion, activation requirements, and T cell receptor (TCR) usage. Based on these findings, highly specific and efficient immune interventions have been designed in EAE and have raised hopes that similar approaches could modulate the disease process in MS. Although the examination of the myelin-specific T cell response in MS patients has shown parallels to EAE, this remains an area of intensive research because a number of questions remain. This review summarizes the important lessons from EAE, examines recent findings in MS, and discusses current concepts about how the disease process develops and which steps might be taken to modulate it.

HLA-DPB1 alleles correlate with risk for multiple sclerosis in Caucasoid and Cantonese patients lacking the high-risk DQB1*0602 allele

Multiple sclerosis (MS) is a demyelinating disease associated with the HLA-DR2-related haplotype DRB1*1501, DQB1*0602 in Caucasoids and with DQB1*0602 in DR2-positive Cantonese. However, many MS patients do not have the high-risk HLA-D determinants and alternative genes may contribute to the pathogenesis of MS. One candidate gene is HLA-DPB1. Our reanalysis of five earlier reports of HLA-DPB1 antigen distributions in Caucasoid MS patients shows a consistent and highly significant increase (p = 1.5 x 10(-5)) in frequency of HLA-DPw3 in the combined data set. This study tests whether HLA-DPw3 (DPB1*0301) is also increased in frequency in Australian and Cantonese MS patients and whether any distortion in DPB1 allelic distributions can be attributed to linkage disequilibrium with DQB1*0602. PCR-RFLPs were used to determine distributions of 20 HLA-DPB1 alleles in 41 Australian MS patients and 67 controls of known DQB1*0602 status and in 11 Cantonese MS patients and 33 controls positive for HLA-DR2. HLA-DP distributions in Australian MS patients and controls positive for DQB1*0602 did not differ, but in those MS patients lacking DQB1*0602, the DPB1*0301 antigen (phenotype) frequency was significantly (p = 0.006) increased (50.0%) when compared with DQB1*0602-negative controls (9.1%). DPB1*0301 was associated (p = 0.003) with DQB1*0402 (DR8) in Caucasoid MS patients.(ABSTRACT TRUNCATED AT 250 WORDS)

HLA-DPB1 gene polymorphism and multiple sclerosis: a large case-control study in the southwest of France

The polymorphism at the HLA-DPB1 locus has been characterized in a large number of patients with multiple sclerosis (n = 112) and in healthy controls (n = 115). Both patients and controls lived in the southwest of France (in the Pyrénées Atlantiques) and had similar ethnic background. The typing procedure involved the selective amplification of the second exon of the DPB1 locus by polymerase chain reaction, followed by hybridization of the amplified DNA with 14 sequence-specific oligonucleotide probes. Individual alleles were identified by the pattern of hybridization of the different probes. The distribution of the DPB1 alleles was not significantly different in multiple sclerosis patients and controls (p = 0.11). This does not corroborate the reported association of multiple sclerosis with the primed lymphocyte typing (PLT)-defined DPw4 specificity and is not in favour of a role played by polymorphic residues of the DP molecule in susceptibility to multiple sclerosis.

HLA class II-associated genetic susceptibility in multiple sclerosis: a critical evaluation

Multiple sclerosis (MS) has, since the 1970s, been known to be associated with the HLA-Dw2 and -DR2 specificities in Caucasian Europeans and North Americans. By the use of genomic typing techniques, the association has been specified to be with the DRw15,DQw6,Dw2, i.e. the DRB1*1501-DQA1*0102-DQB1*0602 haplotype. A significant DPw4 association in Scandinavian MS patients has been described in one report. However, this association has not been confirmed in several subsequent studies with patients from the same and other ethnic groups. During the last few years several reports, based on serological, RFLP and PCR-SSO data, have suggested that the HLA class II-associated MS susceptibility gene(s) may be more closely associated with the DQ than with the DR subregion. The observations that the HLA-DQB1 genes of MS patients share long stretches of sequence motifs and also carry DQA1 alleles encoding glutamine at position 34 of the DQ alpha chain have received considerable attention. It has been suggested that the susceptibility to develop MS might be determined by the corresponding DQ alpha-beta heterodimers either encoded in cis or in trans. We have investigated these issues in a large group of Swedish MS patients (n = 179). We found that the associations with the suggested DQB1 sequences and position 34 of the DQ alpha chain were due to linkage disequilibrium and secondary to the association with the DRw15,DQw6,Dw2 haplotype (p less than 10(-9) and p less than 10(-8), respectively). No overrepresentation of the implicated DQ alpha-beta heterodimers was observed in DRw15,DQw6,Dw2-negative patients.(ABSTRACT TRUNCATED AT 250 WORDS)

HLA-DQA1 and HLA-DQB1 genes may jointly determine susceptibility to develop multiple sclerosis

Serologic DR typing and genomic DRB1, DQA1, DQB1, DPA1, and DPB1 typing using sequence-specific oligonucleotides were performed in 69 multiple sclerosis (MS) patients and 181 healthy controls on in vitro amplified DNA. The frequencies of DR2 as well as the DR2-associated DQA1*0102 and DQB1*0602 alleles were increased whereas DR7 was decreased among MS patients. The distribution of DR4 subtypes as well as DP alleles were similar in patients and healthy controls. All but one of 23 DR4-positive MS patients carried the DQB1*0302 allele, whereas five of five DR7-positive MS patients carried the DQB1*0303 allele. Of the MS patients, 99% compared to 79% of the controls carried DQA1 alleles encoding glutamine at residue 34, while 97% of the MS patients compared to 72% of the controls carried DQB1 alleles encoding DQ beta chains sharing long polymorphic stretches. A combination of such DQA1 and DQB1 alleles was carried by 96% of the MS patients and 60% of the controls, suggesting an association between MS and a combination of particular DQA1 alleles and DQB1 alleles. The corresponding DQ alpha beta heterodimers may have in common an ability to bind a particular peptide.

DNA typing for HLA-DPB1*02 and -DPB1*04 in multiple sclerosis and juvenile rheumatoid arthritis

DP gene typing using in vitro DNA amplification combined with sequence-specific oligonucleotide probes (SSOP) has recently been reported. The amplification step may be specific for the HLA-DPB locus, or it may be specific for one or a group of HLA-DPB alleles, thus increasing the discriminatory power of the system. We report the combined use of group-specific DNA in vitro amplification followed by SSOP in typing for DPB1*02 and DPB1*04 variants. The method was used to type for these variants in 96 randomly selected, healthy Danes, in 37 patients with pauciarticular juvenile rheumatoid arthritis (PJRA), and in 38 patients with multiple sclerosis (MS). Increased frequencies of the cellularly defined HLA-DPw2 in PJRA and of HLA-DPw4 in MS have previously been reported. In the patient groups, the frequencies of the DPB1*02 and DPB1*04 variants did not differ significantly from those expected based on the cellularly defined HLA-DP types of the patients and the frequencies of the DPB1*02 and DPB1*04 variants among healthy Danes.

HLA-DP beta and susceptibility to multiple sclerosis: an analysis of caucasoid and Japanese patient populations

Nonradioactive sequence-specific oligonucleotide (SSO) probes specific for the HLA-DP beta locus have been used in a simple dot-blot assay to DP beta-type samples amplified by the polymerase chain reaction (pcr) from Caucasoid (n = 24) and Japanese (n = 23) patients with multiple sclerosis (ms) as well as ethnically matched controls. In contrast to previous reports, no DP beta allele was found to be increased in either patient population. However, the results do show a dramatic difference in the allele frequencies between the two control populations, further emphasizing the need for ethnically matched controls in studies of HLA and disease.

Molecular basis of human leukocyte antigen class II disease associations

This chapter focuses strictly on the HLA MHC class II genes and molecules with regard to how they contribute to better delineation of the genetic associations and how the current knowledge of their structure, expression, and functions can be used to speculate on their role in the pathogenesis of disease. Because of the strong linkage disequilibrium between loci and alleles, the chapter restricts the description of the genetic associations to only the most recent data, mainly generated by molecular means, and because they supercede in precision and accuracy the previous data obtained by serological methods. Because the HLA system displays the unusual feature of strong linkage disequilibrium between loci and alleles, the genetic traits found to be associated with disease do not emerge at random. The pattern of genetic associations follow an almost constant trend. The associations gain strength each time an additional locus centromeric to the precedent is individualized. The advances made in this respect almost parallel the introduction of progressively more refined typing procedures, which allow the division of former genetic entities (loci and alleles) into additional subtypes. Among the HLA-associated diseases, or at least for those diseases in which an autoimmune process is suspected to be directly relevant to the pathogenesis, the associations are with genes and molecules of the HLA-D region (HLA class II genes and products). The most recent data assigns the disease susceptibility to common amino acid sequences present on an HLA class II molecule within its “active” site.

HLA-DP antigens and HTLV-1 antibody status among Japanese with multiple sclerosis: evidence for an increased frequency of HLA-DPw4

Previously, an association between multiple sclerosis (MS) and HLA-DPw4 has been reported in Scandinavians. In the present study, the distribution of HLA-DP antigens was studied in 34 Japanese MS patients, all of whom fulfilled the criteria for definite MS. HLA-DP typings for DPw1 through w6 and the local specificity, CDP-HEI, were performed using the primed lymphocyte typing (PLT) technique. In addition, the patients were typed for a DR2+, Dw2+/Dw12- related, PLT defined specificity. The distribution of DPw1-w5 in 121 healthy, unrelated Japanese controls were from Nishimura et al., 1984; Nishimura, personal communication). Sera from all 34 patients and 38 controls (both from the HTLV-1 nonendemic, Kyoto region) were examined for the presence of HTLV-1 reacting antibodies by a highly sensitive radioimmuno assay (RIA) using two sources of HTLV-1 antigens, namely total crude protein preparations from disrupted HTLV-1 virions and affinity purified p24 HTLV-1 core proteins. The frequency of DPw4 was significantly increased to 35.3% in Japanese MS patients compared to 16.5% in controls (Relative Risk, RR = 2.8, p = 1.9 x 10(-2)). 41.6% of the MS patients gave clear typing responses with a PLT reagent which recognized a Dw2+ related specificity, which is higher than the frequency of Dw2 (6.8%) in Japanese. Fourteen of the 34 patient sera contrasting to none of the sera from 38 controls contained antibodies of IgG and/or IgM subclasses reacting with the HTLV-1 derived antigens. This difference is highly significant (P less than 1 x 10(-5)).(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations in HLA-DP and HLA-DQ antigen frequency in patients with dermatitis herpetiformis

Dermatitis herpetiformis (DH) is associated with a markedly increased frequency of the HLA class II antigens DR3 and DQw2. To investigate a possible role of HLA-DP (or closely associated genes) in the pathogenesis of DH as well as to confirm the previously described alterations of HLA-DR3 and HLA-DQw2 antigen frequency, we have typed 43 patients with DH for HLA-DP, HLA-DQ, and HLA-DR antigens. All patients with DH had typical clinical and histologic features, as well as granular deposits of IgA at the dermal-epidermal junction by direct immunofluorescence. HLA-DR3 was expressed in 41 of 43 (95%) DH patients, whereas HLA-DQw2 was expressed in all 43 (100%). The overall distribution of HLA-DP antigens in patients with DH was significantly different from that seen in all controls and in HLA-DR3 and HLA-DQw2 controls (p less than 0.02). Examination of the frequency of individual DP antigens revealed that HLA-DPw1 was increased (42% of patients with DH vs 11% of all controls and 26% of DR3 positive controls), but this increase was not statistically greater than that expected due to the disequilibrium linkage of DPw1 with DR3/DQw2. Patients with DH, however, did have a statistically significant decreased frequency of DPw2 (14% of patients vs 31% of all controls and 41% of DR3 positive controls) (pc less than 0.05). Studies of three informative families demonstrated that the DPw2 genes of the DH patients were not present on the haplotype thought to carry a DH susceptibility gene (HLA-A1, HLA-B8, HLA-DR3, HLA-DQw2). A role of HLA-DP region genes in the pathogenesis of DH is further suggested by the observation that HLA-DPw1 was expressed in 82% (9 of 11) of DH patients with IgA antibodies against dietary antigens as compared with only 33% (4 of 12) of patients without IgA antibodies. HLA-DP genes or genes closely linked to them may be important in DH either as markers of the disease haplotype or by direct involvement in its pathogenesis.

Primarily chronic progressive and relapsing/remitting multiple sclerosis: two immunogenetically distinct disease entities

HLA class II gene polymorphism was investigated in 100 patients with clinically definite multiple sclerosis (MS) by restriction fragment length polymorphism analysis of Taq I-digested DNA using DRB, DQA, and DQB cDNA probes. Twenty-six patients had primarily chronic progressive MS and 74 had relapsing/remitting MS. The latter group included patients with a secondary progressive evolution of symptoms. Both clinical forms of MS were found to be associated with the DRw15,DQw6 haplotype. In addition, primarily chronic progressive MS was positively associated with the DQB1 restriction fragment pattern seen in DR4,DQw8, DR7,DQw9, and DRw8, DQw4 haplotypes, as well as negatively associated with the Taq I DQB1 allelic pattern corresponding to the serological specificity DQw7. Relapsing/remitting MS was positively associated with the DQB1 allelic pattern observed in the DRw17,DQw2 haplotype. These three DQB1 alleles are in strong negative linkage disequilibria with DRw15. The two susceptibility markers of each clinical form of MS act additively in determining the genetic susceptibility, as the relative risks for individuals carrying both markers roughly equal the sum of respective risks. Different alleles of the DQB1 locus defined by restriction fragment length polymorphisms contribute to susceptibility and resistance to primarily chronic progressive MS as well as to susceptibility to relapsing/remitting MS. The observed immunogenetic heterogeneity between the different clinical forms of MS favors the hypothesis that primarily chronic progressive MS and relapsing/remitting MS are two distinct disease entities.

Patients with multiple sclerosis carry DQB1 genes which encode shared polymorphic amino acid sequences

Of 61 Norwegian multiple sclerosis patients tested, 59, i.e., 97%, were positive for at least one of the HLA specificities DR2, DR4, or DRw6. Typing with sequence-specific oligonucleotide probes revealed that the same 59 patients carried DR2-, DR4-, or DRw6-associated HLA-DQB1 genes which encode shared polymorphic amino acid sequences in the membrane-distal part of their HLA-DQ beta chains. This shared DQ beta polymorphism may explain previously reported DR associations and could thus be the primary HLA association in MS.

Lupus erythematosus in a patient with long-standing multiple sclerosis

The occurrence of both lupus erythematosus and multiple sclerosis in several members within the same family has been previously documented. In the past, patients manifesting symptoms and findings compatible with both of these diseases have posed difficult diagnostic problems. This report concerns a patient with long-standing multiple sclerosis and in whom cutaneous and serologic lupus erythematosus developed. To our knowledge this is the first such case reported in the English literature. A daughter of this patient had developed serologic lupus erythematosus. The intensified study of patients with both of these diseases and those families with several members with one of these diseases may lead to new insights into the cause and pathogenesis of these disorders.

An analysis of the effect of HLA-DP in the mixed lymphocyte reaction

It has recently been reported that HLA-DP antigens may play an important role in the development of graft-versus-host disease (GVHD) following transplantations of haploidentical bone marrow as a treatment for haematological malignancies. Mixed lymphocyte culture (MLC) is routinely performed prior to bone marrow transplantation to assess the suitability of the donor, and we have therefore examined the role of HLA-DP in this test. One-way MLC chequerboard experiments were performed between 17 HLA-Dw3 homozygous typing cells (HTC) with a range of HLA-DP antigens represented, including HLA-DPw1, w2, w3, w4 and CP63. The experiments were performed on multiple occasions and each time a highly significant difference (P = less than 0.001) was observed between the Relative Responses (RR) in the HLA-DP matched responder/stimulator pairs and the HLA-DP mismatched pairs. There was, however, considerable overlap in these results with ranges in the HLA-DP-matched group RRs of 0-17%, and 0-62% in the mismatched group. Only 3.1% of the HLA-DP-matched grou had a RR greater than 5%, while 48% of the HLA-DP mismatched group had a RR greater than 5%. From these results it was calculated that a positive response (greater than 5%) has a 96% chance of being due to an HLA-DP disparity of one or two antigens. Conversely, with a negative MLC the chance of their being no HLA-DP antigen disparity was only 65%.(ABSTRACT TRUNCATED AT 250 WORDS)

HLA-DP antigens are involved in the susceptibility to multiple sclerosis

Forty-five unrelated patients with multiple sclerosis (MS) from Sweden and 166 Danish controls were typed for HLA-DP using Primed Lymphocyte Typing. Thirty-nine MS-patients and 63 controls were also DNA-typed with the Restriction Fragment Length Polymorphism (RFLP) technique for HLA-DP and -DR genes. The frequencies of DPw4 were 93.3% in MS patients and 72.3% in controls (relative risk, RR = 5.4, p = 0.0014). The DR2 antigen was present in 75.5% of the patients and in 33.7% of the controls (RR = 6.1, p less than 10(-6)). DPw4 was not associated (i.e., was not in linkage disequilibrium) with DR2 in patients or controls. Thus, in MS the associations with DP and DR are independent of each other. However, the combined presence of DPw4 and DR2 gave a significantly higher risk than each antigen alone, indicating that synergism between DP and DR gene products may play a role in the genetic susceptibility to MS.

Human leukocyte antigen-DP in leukemia

Human leukocyte antigen-DP (HLA-DP) typing was performed on patients with chronic myelogenous leukemia (CML, n = 44), acute nonlymphoblastic leukemia (ANLL, n = 34), or acute lymphoblastic leukemia (ALL, n = 41). Frequencies of DPw alleles in CML and ANLL patients were not significantly different from 254 controls, except that in ANNL DPw1 was absent. This was most likely due to the concurrent absence of DR3 with which DPw1 is in linkage. In contrast, in ALL, frequencies of DPw2 and DPw5 were significantly increased (corrected P less than 0.05, relative risk (RR) = 2.19 and corrected P less than 0.01, RR = 6.92, respectively). This was not due to linkage with DR. The frequency of DPw1 also tended to be reduced, but this was not caused by a similar decrease of DR3 in ALL. These results, therefore, demonstrate both positive and negative associations between major histocompatibility complex (MHC) gene products which are in only very weak linkage with the rest of HLA, and acute lymphocytic, but neither acute nor chronic myelogenous, leukemias. The HLA-DP region could thus contain long sought-after genes influencing susceptibility and resistance to leukemogenesis.

HLA-DP in rheumatoid arthritis

Frequencies of HLA-DR, Dw and DPw specificities were compared between rheumatoid arthritis (RA) patients, Felty's syndrome (FS) patients and normal controls. It was confirmed that the frequency of DR4 was increased in RA patients (54% (n = 111) vs 23% (n = 272), relative risk (RR) = 3.98, P less than 0.001). Cellular typing showed a highly significant increase in HLA-Dw14 in the entire RA population (17% (n = 32) vs 2% (n = 242), RR = 11.90, P less than 0.001), and a tendency towards an increase of HLA-Dw14 in DR4+ RA patients compared to DR4+ controls (28% (n = 32) vs 11% (n = 47), RR = 3.29, P less than 0.05). Regarding DPw specificities, the only significance was for a negative association with DPw3 (13% vs 22% (n = 254), RR = 0.51, P less than 0.05), with an additional tendential decrease of DPw1 (11% vs 19%, RR = 0.53, not significant (NS]. The decrease of DPw3 was more marked in DR4- RA patients (RR = 0.33, P less than 0.05) than in DR4+ RA patients (RR = 0.69, NS). In FS patients, 96% of whom were DR4+, decreased DPw1 was very marked, whereas the frequency of DPw3 was unaltered compared to DR4+ normals. These alterations in frequencies were not caused by linkage disequilibria between HLA-DR and -DP alleles. Thus, taken together, these data suggest that, in the presence of the major DR4-associated "susceptibility" gene(s) for RA, DPw1 may have "protective" effects, whereas in the absence of DR4, the presence of DPw3 has significant "protective" activity.

Sex distribution, age of onset and HLA profiles in two types of multiple sclerosis. A role for sex hormones and microbial infections in the development of autoimmunity?

Fifty-four patients with clinically definite multiple sclerosis were typed for HLA-A, B, C, DR and DQ antigens. HLA-DQ was not a better disease marker than the previously described HLA-DR and B markers. The patients were subdivided according to the clinical evolution of their disease, age at onset and sex. HLA-DR2 was significantly associated with females having a relapsing-remitting course of the disease and HLA-B8 and B35 were significantly associated with males having a chronic-progressive course of the disease. A role is postulated for defects in the sex hormone balance in females and for microbial infections in males as dominant environmental triggers in the development of autoreactivity.

Increased frequency of HLA-DPw2 in pauciarticular onset juvenile chronic arthritis

Thirty-six unrelated Danish patients with pauciarticular Juvenile Chronic Arthritis (PJCA) and 120 controls were typed for HLA-DPw1-w6 and the local specificity CDPHEI with bulk-expanded Primed Lymphocyte Typing (PLT) cells. The frequency of HLA-DPw2 was 52.8% in PJCA patients and 16.7% in controls (relative risk, RR = 4.5; P less than 0.001). The antigens HLA-Dw5 and/or Dw8 were present in 50% of the patients and in 21.3% of the controls (RR = 4.2; p less than 10(-3)). DPw2 was not associated (in linkage disequilibrium) with Dw5/w8 in patients or in controls, and the DP and D associations with PJCA were independent of each other. However, the combined presence of DPw2 and Dw5 and/or Dw8 gave a significantly higher risk of PJCA than each antigen alone indicating interaction of DP and DR gene products. PJCA is the first disease definitely found to be associated with a DP antigen.

HLA-DP antigens in patients with pauciarticular juvenile rheumatoid arthritis

The distribution of the recently described HLA-DP antigens was examined in a population of patients with pauciarticular juvenile rheumatoid arthritis and iridocyclitis, in an attempt to further characterize the immunogenetically determined susceptibility to this disease. There was a significantly increased frequency of the HLA-DPw2 antigen in the patients compared with the controls (67% versus 34%; odds ratio 3.9, P = 0.003 by Fisher's exact test). Population studies and family studies showed that this association with HLA-DPw2 was not secondary to linkage disequilibrium with the previously defined HLA-D region markers of disease (HLA-DR5 and HLA-DRw8) in these patients. These data raise the possibility that susceptibility to this form of juvenile rheumatoid arthritis may be regulated by more than one HLA-linked gene.