HLA antigen and haplotype frequencies in Greeks

A random panel of 189 healthy Greek subjects was HLA typed for A, B and DR antigens. The alleles of these loci were found to be in Hardy-Weinberg equilibrium. Compared with other European Caucasoid populations, the frequencies of A9, B5, B18, B35, DR2 and DR5 were raised and that of B8 lowered. Significant linkage disequilibrium was found between a number of A/B, B/DR and A/DR antigen combinations. Some of the antigen associations usually seen in Caucasoid populations were also present in this sample (A1-B8-DR3, B14-DR1, B15-DR4) although others were missing (A3-B7-DR2, B35-DR1, B44-DR4). In addition, some antigen combinations have not been previously described. The most frequent two locus haplotypes in the Greek population are B8-DR3 and B18-DR5.     

HLA-linked SB antigens in Israel

In the present study we have investigated the HLA-SB antigen distribution in 65 unrelated Israeli Ashkenazim and non-Ashkenazim and in a panel of 18 local homozygous typing cells (HTC). Two locally derived SB reagents, anti-SB2 and SB3, were also studied. The HLA-SB allele frequencies in the Israeli sample ranged from 0.02 for SB1 to 0.47 for SB4 while SB5 was absent. SB3 had a higher frequency in non-Ashkenazim (0.11) as compared to Ashkenazim (0.06) but this difference was not significant. On the whole, the allele frequencies for the 5 HLA-SB antigens studied were in the range observed in non-Jewish Caucasoid populations with some minor variations. Two of eighteen local HTC's were found heterozygous for SB, demonstrating that homozygosity for HLA-A, B, C, D and DR does not indicate homozygosity for HLA-SB. The local anti-SB2 and SB3 typing reagents gave concordant results when compared with the NIH reference typing cells in population studies.     

HLA-A, B, DR antigens and insulin-dependent diabetes in Algerians

HLA-A, B and DR antigens have been investigated in insulin-dependent diabetics and compared to controls in a population of Algerians. A decrease of A1 and DR2 and an increase of Aw 19.2; B8, B18 and especially DR3 were found in diabetics in comparison to controls. The strongest association was found for DR3, which is a good genetic marker of IDD (RR = 8.50) in this population. The frequency of some HLA antigen associations in IDD suggests that the diabetic gene(s) is linked to 2 main haplotypes: Aw 19.2; B18; DR3 and Aw 19.2; B8; DR3. Antigen DR4 was equally represented in IDD (21%) and controls (28.4%), but heterozygote DR3-DR4 was more frequent in diabetics. The relation between IDD and HLA antigens found in the Algerian population is very similar to that described in diabetic Caucasian populations of southern Europe, except for the lack of association with DR4.     

Population studies of HLA-linked SB antigens and their relative importance in primary MLC typing. Analysis of HLA-D homozygous typing cells and normal heterozygous populations

SB phenotyping was undertaken on 96 HLA-D homozygous typing cells (HTCs) and 129 normal unselected heterozygous donors in the German population, using Interleukin-2-propagated primed lymphocyte typing (PLT) reagents. The results showed that the SB antigens in the normal population behave as a system of alleles at a single locus in Hardy-Weinberg equilibrium (p approximately equal to 0.20). Estimated gene frequencies in the German population appeared to be significantly different (p less than 0.002) from the North American Caucasian population: the principal differences were increased frequencies of the specificities SB1 and SB4, and decreased frequencies of blanks. Of HLA heterozygous donors 41% typed for two distinct SB specificities; 57% typed for one; and 2% were blank. In the HTC group, 20% typed for two specificities; 68% typed for one; and 12% were blank. Thus, a significant proportion of HLA-D homozygous test cells were, nonetheless, heterozygous for HLA-linked SB antigens. Performance of checkerboard mixed leukocyte cultures (MLCs) between 16 SB typed HLA-Dw3 HTCs, however, did not indicate that the observed mutual or one-way responses were influenced in any simple way by SB antigens; neither heterozygosity nor assumed homozygosity for SB antigens appeared to influence the frequency of MLC typing responses of HLA-Dw3-positive donors on these HTCs. These results add further confirmation of the genetic and functional independence of the SB gene product(s) and the HLA-D/DR gene product(s).     

HLA antigens in Asian Indians: HLA-D-DR relationships

Fifty-nine Asian Indians were typed for HLA-A, B, D, and DR antigens. Peculiar to the population that we have tested was the absence of HLA-A25, B13, B14, DR1, DW1, LD13 (a DR1-associated HLA-D allele), and LD12 (a DR4-associated HLA-D allele). Certain haplotypes that exhibit high frequencies in Caucasians (such as A2-BW50, AW24-B18, B8-DR3, BW44-DR7, B18-DR5) or in Blacks (such as A29-B7) also show significant delta in Asian Indians. The HLA-D-DR associations previously described in European and North American Causcasians were also found in Asian Indians. Additionally, however, Asian Indians exhibited two new HLA-D antigens, one associated with DR5 and the other with DRw6. The genetic distance between Asian Indians and Caucasians, Blacks, or Mongoloids is of the same order of magnitude.     

HLA and GM in insulin-dependent diabetes in the Netherlands: Report on a combined multiplex family and population study

This report deals with the genetic factors involved in insulin-dependent diabetes mellitus (IDD) in The Netherlands. Twenty-two Dutch multiplex families with IDD were typed for HLA-A, -B, -C, and -DR antigens for BF, C2, C4 and GLO polymorphisms, as well as for GM allotypes of immunoglobulins. In addition, 53 unrelated IDD children and 31 unrelated patients with adult onset IDD were typed for HLA-A, -B -C, and -DR antigens. A significant heterogeneity for the frequency of HLA-DR4 related to age of onset was observed. A significant deviation of the Hardy-Weinberg equilibrium was observed for the HLA-DR locus with an excess in patient of heterozygotes HLA-DR3, -DR4, HLA-B8 amd HLA-B15 were not only secondary associated, but constituted with HLA-DR3 and -DR4, respectively, a haplotype in association with IDD. Nonrandom segregation of HLA-haplotypes was observed in multiplex families ex-emplified by an excess of HLA-identical affected sibpairs. Cross-over between HLA-DR and GLO identified the HLA-DR segment as mainly invovled in the association with IDD. Three diabetic haplotypes were confirmed to occur frequently among affected sibs: (a) A1, B8, BFS, C2.1 C4AQ0, C4B1, DR3, GLO2; (b) Aw30, Cw5, B18, BFF1, 22, C4A3, C4BQ0, DR3, GLO2; (c) A2, Cw3, B15, BFS, C2.1, C4A3, C4B3, DR4, GLO1, The segregation of GM allotypes to affected sibpairs was not significantly different from random segregation. The main conclusions from this study are that significant heterogeneity for age of onset exists and that the data are not compatible with simple genetic models including dominant, recessive, and intermediate models of inheritance. The data do require more complex models, involving two different HLA-linked (sets of) susceptibility genes.     

HLA-linked B cell alloantigens of a new segregant series: Population and family studies of the SB antigens

In order to define new human histocompatibility antigens, we have generated primed lymphocytes using responder and stimulator cells matched for all recognized HLA-linked histocompatibility antigens (A,B,C,D,DR,MB). Many such primed lymphocytes give highly discriminatory proliferative responses specific for antigens which differ between HLA-A,B,C,D,DR, and MB matched restimulating cells. Five distinct antigens have been defined which appear to be part of a single segregant series (designated “SB”). Studies in a DR/GLO recombinant family indicate that the antigens are coded by an HLA-linked gene telomeric to GLO. Family studies of 57 HLA haplotypes provide an estimate of genotype frequency which is 12% or less for four of the SB alleles but approximately 50% for the most common (SB4, which may be a “public” determinant); approximately 25% of haplotypes are black. Population studies of one of the SB antigens (SB1) suggest that it is in linkage disequilibrium with A1, B8, and DRw3. These results, together with results of other studies [1], indicate that the SB antigens are part of a highly polymorphic new segregant series of B cell alloantigens encoded by a gene that maps between HLA-B and GLO.     

Correlations between HLA-D/DR associated Primed Lymphocyte Typing (PLT) defined DP-antigens, HLA-D and HLA-DR antigens

A panel of 79 individuals were typed for HLA-D/DR associated Primed Lymphocyte Typing (PLT) defined "DP"-antigens, HLA-D and HLA-DR antigens. Typing for DP-antigens was carried out with local PLT-cells. HLA-D and-DR typing was performed with all homozygous typing cells and all DR-antisera included in the 8th International Histocompatibility Workshop. Assignments of DP-, HLA-D-and HLA-DR-antigens were done independently and the correlations between DP/D/DR1–8 were analyzed. The panel included random unrelated individuals, and individuals previously found to have one or no identifiable HLA-D antigen (B). In the random group, 80% of the individuals were assigned to possess the same antigen with the 3 techniques, while this was only the case in 46% of B-group individuals. The overall correlation coefficients, r, for the antigens HLA-Dw/-DR/DP1–8 were 0.95 (DP/D), 0.94 (DP/DR), and 0.89 (D/DR). There is a remarkably strong correlation between HLA-D and-DR typing results concerning D/DR1–8, in particular in random individuals. It is possible to select PLT-cells that give typing results which are almost identical to those of HLA-D and-DR typing. When discrepant results were seen, HLA-DR was in general "broader" than DP which in turn was broader than HLA-D, indicating that it may be possible to split HLA-DR/DP1–8 into more "narrow" specificities.     

Production of a cytotoxic human monoclonal antibody with specificity for HLA-DR4 and -DRw10 by cells derived from a highly sensitized kidney recipient

A human monoclonal antibody which reacts preferentially with HLA-DR4 and -DRw10 B-cell targets has been produced. A human B-cell line, secreting antibody which reacted preferentially with DR4 and DR1 targets, was derived from a highly sensitized kidney recipient who had rejected two grafts. This line was fused with the mouse myeloma P3X63Ag8.653 and a selected hybridoma cloned. The clones secrete IgM(lambda), which reacts strongly with HLA-DR4 and -DRw10 and more weakly with -DRw14 and a proportion of -DR1 B cells in cytotoxicity assays. Using B-cell lines as targets in cytotoxicity and enzyme-linked immunosorbent assays, the antibody gives a broader pattern of reaction, reacting with HLA-DR1, -DR4, -DR9, -DRw10, -DRw14, and some -DR2 targets. The antibody (NI) is currently in use as a reagent for tissue typing.     

Alloactivated long-term cultured human T lymphocytes express both HLA-DR and SB antigens but lack lymphocyte stimulation capacity

Cell populations obtained from mixed leukocyte cultures of 6- or 10-day duration were found specifically to restimulate primed lymphocytes detecting HLA-linked SB as well as HLA-D-associated antigens. After expansion in vitro (9-75 days) with medium containing interleukin 2, the cultured cells expressed the T lymphocyte markers detected in indirect immunofluorescence by monoclonal antibodies Lyt-3, OKT3, OKT4, OKT8, and had high levels of HLA-DR antigens. In addition, they were shown in cell-mediated lymphocytotoxicity specifically to express SB antigens of the donor B cell type. Despite their positivity for DR and SB antigens, such cultured T cells failed to restimulate either SB- or D-specific secondary lymphocyte proliferation. Homogeneous cloned populations of cultured T cells also lacked lymphocyte stimulation capacity. In contrast, B cell lines, which also expressed DR and SB antigens, were potent stimulators of both SB- or D-directed proliferation. These data show that the activated T lymphocytes which express both HLA-DR and SB antigens are by themselves unable to stimulate lymphocyte proliferation.     

HLA haplotypes in Koreans based on 107 families

Abstract: There are marked differences in the distribution of HLA haplotypes among different populations, and multilocus HLA haplotypes can best be studied by family analysis. In the present study, 107 Korean families were analyzed for HLA-A, B, C, DR, and DQ antigens and haplotypes. Allele frequencies of more than 10% for class I antigens were A2, A24, A33, B44, B62, Cw1, Cw7, Cw9, Cw10, and C blank (CBL) and those for class II antigens were DR4, DR8, DR13, DR15, DQ1, DQ3, DQ4 and DQ7. In the analysis of HLA haplotypes, 18 kinds of A-B-DR and 11 kinds of A-C-B-DR-DQ haplotypes occurred at frequencies of more than 1%, comprising 34% and 24% of the total theoretical haplotypes, respectively. The five most common A-B-DR haplotypes were exclusively related with the five most common A-C-B-DR-DQ haplotypes (frequency>2%). These remarkably conserved five-locus haplotypes in Koreans were A33-CBL-B44-DR13-DQ1 (5.4%), A24-Cw7-B7-DR1-DQ1 (3.5%), A33-Cw7-B44-DR7-DQ2 (3.0%), A33-Cw10-B58-DR13-DQ1 (2.3%), and A30-Cw6-B13-DR7-DQ2 (2.3%). Comparison of the distribution of A-B-DR haplotypes among East Asian populations revealed that Koreans are closest to Japanese, but show a higher degree of polymorphism in the distribution of HLA haplotypes compared to Japanese. The results obtained in this study will be useful as basic data on Koreans for anthropology and organ transplantation.     

Typing for HLA-D/DR Associated DP-Antigens with the Primed Lymphocyte Typing (PLT) Technique

A total of 74 healthy unrelated random individuals and 36 patients with juvenile rheumatoid arthritis (JRA) were typed for HLA-D antigens with the homozygous typing cell technique and typed for HLA-D/DR associated DP-antigens with the primed lymphocyte typing (PLT) technique. All patients and some of the controls were also HLA-DR typed with a limited battery of anti-DR sera. Selected PLT-cells, specific for the HLA-D/DR antigens D/DRw1-8 and the local specificity D"H" were used. The results of the PLT-experiments were evaluated with the Normalized Median Response (NMR) method and the further procedure of DP-antigen assignment was analyzed. The DP-antigen assignments could be done solely according the NMR-values in approximately two thirds of the individuals. In the remaining individuals, further interpretation of the experimental data had to be done for the assignment of DP-antigens. The correlation coefficients were estimated between the HLA-D assignments and (i) the individual PLT-cell NMR-values with a fixed cut-off for positive reactions and (ii) the DP-antigen assignments. These coefficients were 0.79 and 0.92, respectively. The correlations between HLA-D, -DR and DP-antigen assignments of the specificities HLA-D, -DR and DP1, 2, 3, 4, 7 and 8 were analyzed in 42 controls and 36 JRA patients. The total correlation coefficients were: (i) HLA-D/DR: r = 0.78; HLA-DR/DP: 0.77; and HLA-D/DP: 0.96. The DP-antigen assignments correlated significantly better with HLA-D than with the HLA-DR antigen assignments, which does not agree with other studies. The DP-antigen frequencies among the controls were calculated and the estimated sum of gene frequency corresponding to definable DP-antigens was 0.94 indicating that about 12% of random individuals possess as yet undefined DP-antigens.     

Cell membrane polymorphisms coded for in the HLA-D/DR region I. Relation between D and DR

The relation of HLA-D and -DR determinants was studied in Dutch Caucasoids. The recognition of subgroups of DR4, DR5, and DR7, and the specificities LB12 and LB13 are described. Phenotype and gene frequencies and a Hardy-Weinberg analysis of DR and local (LB) B-cell groups are given. Excellent correlation between D and DR typing was obtained when HTCs were studied by selected B-cell antisera. When the same sera were used to type a panel of D typed cells, the correlation was decreased (with the exception of DR3 and Dw3). In the case of discrepancies the DR specificity, but not the corresponding D specificity, always could be found and not the other way around.

The data fit best the assumption that HLA-D and -DR are carried by the same molecule, although they might be different determinants on this molecule. A number of possible explanations for the observed discrepancies has been given.     

Genetic heterogeneity of diabetes and HLA

Histocompatibility (HLA) antigens and genotypes B, D and DR were studied in a large sample of Caucasian insulin dependent diabetic (IDD) probands. The associations between IDD and B8, B15, Dw3, Dw4, DR3, and DR4 were measured by relative risks (RR) and delta values (δ). Both the homozygotes (B8/8: RR 10, B 15/15: RR 7, DR3/3: RR32, DR4/4: RR34) and the heterozygotes (B8/15: RR 11, DR3/4: RR 46, Dw3/4: RR 22) for the high-risk antigens showed highly significant elevation of the relative risks, yet there were no statistically significant differences between the homo- and the heterozygotes. The δ measurements supported the RR results. RR and δ were found significantly decreased for B7, Dw2, and DR2. There were no relationships observed between age at diagnosis or family history and HLA. Although we were unable to demonstrate a statistically significant difference between the RR for the high-risk antigens heterozygote vs. the high-risk antigen homozygotes, our study like many others shows that the RR is higher for the heterozygotes. Thus our data are compatible with genetic heterogeneity of IDD.     

Influence of Histocompatibility Antigens in Recurrent Spontaneous Abortion Couples and on Their Reproductive Performances

PROBLEM: To determine if human leukocyte antigens (HLA) play any role in the aetiology of recurrent spontaneous abortion (RSA), a substantial group of RSA couples were studied, and their reproductive performances in a 3-year follow-up recorded. METHODS: HLA typing was performed for HLA-A, -B, and DR antigens in both partners of 75 couples with unexplained RSA, and compared with a control group of 30 fertile couples that never experienced abortion. A further 57 couples of this group were studied for their reproductive performance in a 3-year follow-up, and subdivided into three subgroups: 1) couples that achieved successful pregnancy during the follow-up; 2) couples that experienced abortion and no livebirth during the follow-up; and 3) couples that experienced infertility during the follow-up. RESULTS: There were no significant differences for antigen frequency in all the different HLA loci, and HLA antigen sharing between all the RSA couples and controls. Significant increase of sharing for HLA-DR locus was observed in the couples that aborted during the follow-up with respect to the couples that achieved livebirth and controls (P < 0.03 and P < 0.02 respectively), and significantly increased frequency of B44, DR5 antigen combination in the same comparison (P < 0.03). No significant differences were observed in terms of the interval between conceptions in couples without antigen sharing with respect to couples with 1, 2 or more antigens shared, and antigen sharing in Locus A, B or DR. CONCLUSIONS: The results suggest that gene(s) disadvantageous for reproduction may exist between the HLA-B and -DR chromosomal region which influences the pregnancy outcome in RSA couples, and that HLA-antigen sharing itself does not influence the outcome.     

DNA polymorphism of major histocompatibility complex class II and class III genes in systemic lupus erythematosus

We investigated the Taq I digested DNA restriction fragment length polymorphism (RFLP) of the Major Histocompatibility Complex (MHC) class II genes: HLA-DRB, -DQA, and the class III genes: C4 and 21-hydroxylase(CYP21) in 56 caucasoid patients with systemic lupus erythematosus (SLE) and 62 control subjects in order to define the molecular variation of these genes and their association with SLE. The results showed that the gene frequencies of both HLA-DR2 and -DR3 were significantly increased in the SLE population compared to normal subjects (DR2: 21.4% vs 10.7% chi 2 = 4.5. DR3: 29.6% vs 13.3%; chi 2 = 8.3). A high frequency of C4A and CYP21A gene deletions was also found in SLE patients (SLE 52%, normals 24%). All of 22 SLE patients, and 12 of 15 normal subjects who had C4A and CYP21A gene deletions had a 10.0kb Taq 1 DRB RFLP attributable to the presence of HLA-DR3. Family studies showed linkage of C4A/CYP21A deletions with HLA-B8 and -DR3, and confirmed the previously demonstrated association of the HLA-B8, DR3, C4A*Q0, C4*B1, Bf*S, C2*C haplotype with SLE. Deletions affecting the C4A and CYP21A genes were the commonest cause of C4A null alleles in SLE. No strong association between C4 null phenotype or C4 gene deletion, as determined by RFLP, was observed in patients who possessed DR2.     

HLA in juvenile dermatitis herpetiformis: clinical heterogeneity correlated with DNA and serological polymorphism

A group of 30 Italian children affected by Dermatitis Herpetiformis (DH) was analysed for HLA region polymorphisms with both serological and DNA methods. Serological typing was performed on HLA-A, B, C, DR, DQ antigens and C4A, C4B, Bf polymorphisms. DNA RFLPs obtained with TaqI enzyme were investigated with cDNA probes specific for DR beta, DQ alpha and DQ beta genes. The results were correlated with intestinal involvement and age at onset of the disease. The following observations were made: (1) the intestinal biopsies revealed a direct correlation between degree of lesions and age at onset of DH; (2) a significantly increased relative risk (RR) was found for the following HLA antigens: A1 (RR = 2.2), B8 (RR = 6.2), Cw7 (RR = 3.9), C4AQ0 (RR = 7.4), DR3 (RR = 5.2), DR7 (RR = 4.4), DRw53 (RR = 4.7), DQw2 (RR = 6.0); (3) B8 and DR3 were significantly more frequent in patients with severe intestinal lesions; and (4) of the two DR3 subtypes revealed by RFLP typing, only 3.1 showed an increased frequency in DH patients (RR = 8.4). It is suggested that the susceptibility to Juvenile DH is determined by the same genes, within the HLA region, that are associated with Coeliac Disease.     

HLA-A, B, C; -DR; -MT, -MB, and SB antigens on unstimulated human endothelial cells

Since major histocompatibility complex (MHC) antigens of class II play an important role in organ transplantation, we attempted to demonstrate their expression on endothelial cells which are abundant in transplants with vascular blood supply. Our analysis was performed with monomorphic and polymorphic monoclonal antibodies employing a microscopic immunofluorescence assay and flow cytometry on unstimulated endothelial cells isolated from umbilical cord veins. No evidence was found for the presence of HLA-DR antigens and determinants associated with MT, MB and SB. MHC class I antigens exhibited reduced expression. These findings were confirmed in respect to alloantigens by the use of conventional cytotoxic tissue typing antisera. MB and SB antigens were present on most cord B lymphocytes, but could only be demonstrated on a subpopulation of monocytes exhibiting a lower antigen density at the cell surface. MT and DR antigens were found on most cord monocytes and B lymphocytes.     

HLA in Buerger's disease

Recent studies have focused on the possible genetic factor(s) in the pathogenesis of Buerger's disease as well as in Takayasu's disease. We investigated HLA-A, B, C, DR, and DQ antigens in 59 patients with Buerger's disease to confirm statistically significant high frequencies of Aw24, Bw40, Bw54, Cw1, and DR2 antigens and a low frequency of DR9 and DRw52 as compared with those in 152 normal Japanese individuals. As the haplotpye Aw24-Bw54-Cw1-DR4 is known to be common among Japanese, a significantly high frequency of haplotype Bw54-DR2 found in cases of Buerger's disease, instead of that of Bw54-DR4, may suggest a possible cross-linkage occurrence in chromosome 6, which could prove to be an important causative phenomenon in the pathophysiology of Buerger's disease.     

HLA polymorphism and probability of finding HLA-matched unrelated marrow donors for Chinese in Taiwan

Tzu Chi Taiwan Marrow Donor Registry (TCTMDR) was established in 1993 to recruit and HLA-type volunteers who would be willing to donate bone marrow. TCTMDR is currently the largest marrow registry for Chinese in the world, with over 150,000 prospective donors registered as of July 1997. We present here the gene and haplotype frequencies based on 80,353 HLA class I-typed and 18,217 HLA class II-typed healthy Chinese in Taiwan. The resulting frequencies are used for estimating the probability of finding an HLA-matched donor for a patient. The common HLA class I antigens include Al (gene frequency: 32.9%), A2 (29.7%), A24 (17.5%) and A33 (11.0%); B60 (18.1%), B46 (12.8%), B58 (9.8%) and B13 (7.8%); Cw3 (51.4%), Cwl (11.6%) and Cw7 (8.6%). The common HLA class II antigens are DR4 (16.6%), DR9 (15.6%), and DR12 (14.0%); DQ7 (20.7%), DQ9 (12.7%), and DQ5 (12.1%). The common two-locus haplotypes observed with a P -value less than 0.001 are A2-B46 (haplotype frequency: 8.5%), A33-B58 (7.5%), A11-B60 (6.6%); B58-DR17 (7.0%), B46-DR9 (6.4%) and B60-DR4 (4.9%). The common three-locus haplotypes are A33-B58-DR17 (5.3%), A2-B46-DR9 (3.9%) and A11-B60-DR4 (2.0%). As expected, the gene frequency pattern of Taiwanese is more closely related to that of southern Hans than to the pattern of northern Hans, Japanese, Caucasians and African-Americans. Using our registry, 323 of 571 domestic patients (57%) successfully identified one or more matched donors. The empirical result correlated well with a mathematical simulation having an estimated 59% match when donor pool reaches 150,000.