Correlation between HLA-D/DR associated primed lymphocyte typing (PLT) defined DP-antigens, HLA-D and HLA-DR antigens

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 antigen frequencies in juvenile chronic arthritis

HLA-A, B, C, D, and DR typing was performed in 104 patients with Juvenile Chronic Arthritis (JCA). The majority of these (88 patients) participated in a follow-up study of a series of consecutive patients including patients in remission. The study confirmed that JCA is positively associated with B27, Dw8, and possibly Dw5, and negatively associated with Dw2 and Dw7. In JCA patients in remission, the frequency of Dw4 was significantly decreased to 5.0%, compared with 25.0% in healthy Danes and 23.7% in JCA patients with active disease. In pauciarticular onset JCA, the frequency of Dw4 was significantly decreased to 8.1% compared with 25.0% both in controls and in polyarticular onset JCA. These data indicate that Dw4 may be a risk factor of chronicity and multiple joint involvement in JCA. Chronic iritis was present in 18.2% of Dw8-positive patients, compared with 7.0% in Dw8-negative patients, and the frequency of Dw8 was 50.0% in JCA patients with chronic iritis. Thus, Dw8 may be a risk factor of chronic iritis in JCA. Genetically, three distinct subgroups seem to exist: (i) a B27-associated group; (ii) a D/DR5- and D/DRw8-associated group, and (iii) a D/DR4-associated group.

Primed lymphocyte testing specificity of alloreactive lymphocyte clones for HLA-B locus determinants

We have generated two alloreactive T-lymphocyte clones that recognize the products of the HLA-B locus. The primed lymphocyte testing (PLT) reactivity of clone HJ21 was monospecific for the HLA-B antigen Bw49, a subtype specificity of HLA-Bw21. The PLT specificity of clone RD3 was strongly associated with HLA-Bw21. Several monoclonal antibodies against class I HLA molecules inhibited the PLT responses of these clones whereas class II monoclonal antibodies had no effect. These observations provide experimental evidence that class I products of the HLA-B locus may directly be involved in lymphocyte alloactivation.

Characterization of human T-lymphocyte clones (TLCs) specific for HLA-region gene products

Clones of lymphocytes, primed in vitro to HLA-DR1;Dw1, were tested for allospecific proliferation on a panel of thirty-one HLA-phenotyped stimulating cells. No clone was restimulated exclusively by cells sharing the DR1;Dw1 priming antigens and most clones were restimulated by subsets of cells bearing DR1;Dw1. Generally, positive responses were at least 20-fold higher than autologous negative controls. Peak proliferative responses occurred around 72 h and varied, depending on the stimulating cell as well as the responding clone. Selected clones were induced to proliferate only by cells incapable of forming rosettes with sheep erythrocytes. Specific proliferation by TLCs was blocked by monoclonal DR-specific antibodies, but not by monoclonal anti-Thy 1.2. Genetic studies demonstrated that TLCs detected some cell-surface determinants that are encoded by genes in linkage disequilibrium with HLA and others that may not be linked to the human major histocompatibility complex.

Association of PLT specificity of alloreactive lymphocyte clones with HLA-DR, MB and MT determinants

The HLA-D region encodes for several serologically defined systems, including DR, MB, and MT. The antigens of MB and MT are strongly associated with two or more DR specificities. The purpose of this study was to determine the role of MB and MT antigens in lymphocyte alloactivation. A soft agar colony assay was used to generate alloreactive lymphocyte clones primed in mixed leukocyte culture against a stimulator who typed as HLA-DR4,-;MB3,-;MT3,-. In secondary primed lymphocyte typing (PLT) assays, several clones were identified with PLT specificities strongly associated with DR4, MB3, or MT3. The data suggest that HLA-D controls different lymphocyte-activating determinants associated with the serologically defined DR, MB, or MT antigens.

HLA-DR phenotype and HLA-B,DR haplotype frequencies in 704 unrelated Danes

HLA-ABC and DR antigens were studied in 704 unrelated Danes (84 cadaver kidney donors, 307 healthy individuals, and 313 uremic patients), HLA-DR1, 2, 3, 4, 7, w8, and w10 were investigated in all individuals, whereas DR5, "DRw6", and w9 were only studied in parts of the material. The frequencies of DR1, 2, 3, 4, 5, and w10 were similar in the three groups, while those of "DRw6", DR7 and w8 differed significantly. The deviation of the DR7 frequency was small and probably due to change; "DRw6" is considered difficult to define, and DRw8 may have been difficult to define in the early part of the material. DR-phenotype distributions showed perfect fits to Hardy-Weinberg expectations for the three groups separately and for the combined group. When our combined DR antigen frequencies were compared with those from another Danish sample (Madsen et al, 1981), significant differences were found for "DRw6", w8 and w10. However, in general, the same HLA-B,DR phenotype combinations showed significant positive associations in the two samples, and most of the corresponding haplotype frequencies and delta values were quite similar.

HLA-D and -DR antigens in genetic analysis of insulin dependent diabetes mellitus

Three groups of patients with insulin-dependent diabetes mellitus, ascertained by different procedures, were investigated for HLA-A, B, C and D antigens (n = 164), and a subset (n = 93) for HLA-DR. Both HLA-D/DR3 and D/DR4 were strongly positively associated and D/DR2 was negatively associated with insulin-dependent diabetes. HLA-DR+ was found to be a better marker for insulin-dependent diabetes than Dw4. The HLA-B associations (B8, B15 and B18) were clearly secondary to the increases of HLA-D/DR3 and D/DR 4. The HLA associations did not differ between familial and isolated cases indicating that these two groups may well have a common genetic background. Based on analysis of HLA-haplotype sharing in affected sibling pairs, a simple dominant model of inheritance could be ruled out, and a simple recessive model was found unlikely. The relative risks for the HLA-Dw3,4 and HLA-DR3,4 phenotype were 21.2 and 44.4 respectively and exceeded those of both the HLA-Dw3 and HLA-DR3 (5.6 and 4.3) as well as the HLA-Dw4 and DR4 (10.1 and 10.5) phenotypes. This argues against an intermediate genetic model but further studies are needed to clarify whether there is more than one susceptibility gene for insulin-dependent diabetes mellitus within the HLA-system.

Detection of HLA-D region products by primed lymphocyte typing (PLT)

In vitro priming experiments were performed with lymphocytes from members of two different families carrying Dw-,DR2 or Dw2,DR2 haplotypes. It was demonstrated that lymphocytes could be primed to allogeneic HLA-D determinants without detectable priming to the associated HLA-DR determinant, even when the priming cell was also HLA-DR incompatible to the responding cell. It was further shown that the unknown HLA-D determinants of the two families (e.g., Dw-) were different, one of them showing cross-reactivity to Dw2. Priming to MT1 determinants or to Lewis antigens could not be detected.