Previous testing of patients with rheumatoid arthritis showed that one HLA-D type, Dw4, occurred more frequently than in normal controls. B-cell alloantigens closely related to HLA-D can now be identified by a simple serologic procedure. Using this test, I studied 80 white patients with erosive, rheumatoid-factor-positive rheumatoid arthritis. The B-cell alloantigen HLA-DRw4 occurred in 70 per cent of 54 patients, as compared to 28 per cent of the 68 normal controls (P less than 10(-5)). Both groups were also tested for the HLA-A, B and C antigens and for HLA-D. HLA-Dw4 occurred in 54 per cent of the patients and 16 per cent of the controls (P less than 10(-5)). Small differences observed in several of the HLA-A and B antigens were not statistically significant. The results indicate that rheumatoid arthritis in whites is associated with genes of the HLA-D region and that immunogenetic factors linked to HLA have a role in its pathogenesis.

Presensitization of kidney-transplant recipients against MICA antigens is associated with an increased frequency of graft loss and might contribute to allograft loss among recipients who are well matched for HLA.

A gene involved in psoriasis susceptibility was localized to the distal region of human chromosome 17q as a result of a genome-wide linkage analysis with polymorphic microsatellites and eight multiply affected psoriasis kindreds. In the family which showed the strongest evidence for linkage, the recombination fraction between a psoriasis susceptibility locus and D17S784 was 0.04 with a maximum two-point lod score of 5.33. There was also evidence for genetic heterogeneity and although none of the linked families showed any association with HLA-Cw6, two unlinked families showed weak levels of association. This study demonstrates that in some families, psoriasis susceptibility is due to variation at a single major genetic locus other than the human lymphocyte antigen locus.

There is evidence that certain alleles at the HLA-DQ locus are correlated with susceptibility to insulin-dependent diabetes mellitus (IDDM) and in particular that DQ beta-chain alleles containing aspartic acid at position 57 are protective. The availability of a large group of patients with IDDM enabled us to assess the role of HLA-DQ alleles in susceptibility to the disease in order to confirm and extend recent observations derived from studies of smaller numbers of patients. Using allele-specific oligonucleotide probes and the polymerase chain reaction, we studied 266 unrelated patients with IDDM and 203 unrelated normal subjects for eight HLA-DQ beta-chain alleles. Two major findings emerged from these studies. First, the presence of an HLA-DQw1.2 allele was protective. Only 6 of the 266 patients with IDDM (2.3 percent) were positive for HLA-DQw1.2, as compared with 74 of the 203 normal subjects (36.4 percent; P less than 0.001). Thus, persons with the HLA-DQw1.2 allele, which is one of the polymorphic forms of the beta chain of the HLA-DQ molecule, rarely had IDDM, no matter which other HLA-DQ beta-chain allele they inherited ("dominant protection"). Second, the presence of the HLA-DQw8 allele increased the risk of IDDM. The relative risk of IDDM was 5.6 in persons homozygous for HLA-DQw8, and it was similar in persons with the HLA-DQw1.1/DQw8 or HLA-DQw2/DQw8 haplotype ("dominant susceptibility"). However, the relative risk of IDDM in persons who had the HLA-DQw1.2/DQw8 haplotype was 0.37, demonstrating that the protective effect of HLA-DQw1.2 predominated over the effect of HLA-DQw8. We conclude that the presence of the HLA Class II antigen DQw1.2 is strongly protective against the development of IDDM, and that complete HLA-DQ typing is necessary for accurate assessment of susceptibility to IDDM.

No abstract

MICA is a new polymorphic gene in the HLA region expressed in epithelial cell lines and gastrointestinal epithelium. Little is yet known about the MICA protein, and the pattern of its expression by freshly isolated cells has not been established. In the present experiments, we used antibodies raised in rabbits against alpha1 and alpha2 domain-peptides to study the expression of MICA. By western blot and immunoprecipitation, we detected a band of 62 000 Mr in various cell lines (THP-1, U937, HeLa, A431, Raji, MOLT-4, and HUV-EC-C) and in freshly isolated keratinocytes, endothelial cells, and monocytes but not in CD4+ and CD8+ T cells, and CD19+ cells (B lymphocytes). It was not possible to up-regulate the expression of MICA in different cells by stimulation with gamma-interferon, but the expression of MICA was induced in phytohemagglutinin-stimulated T cells. We confirmed that MICA is expressed at the cell surface by flow cytometry. Results of immunoprecipitation studies of beta2-microglobulin (beta2m)- or MICA-depleted, metabolically labeled HeLa cells indicated that MICA was not associated with beta2m. Although the function of MICA is still unknown, its restricted pattern of tissue expression, the fact that it is expressed on the cell surface, and its polymorphic nature suggest that this new molecule, encoded close to HLA class I, may play a role in the interaction between epithelial cells and cells of the immune system.

We studied the autoimmune serologic features and histocompatibility antigen associations of 27 patients who had a widespread, nonscarring and often photosensitive form of histologically specific cutaneous lupus erythematosus. We designated this disorder as subacute cutaneous lupus erythematosus. Skin lesions from this disorder can be distinguished from scarring discoid lupus erythematosus lesions both on a morphologic and histopathologic basis. Antinuclear and anticytoplasmic antibodies (Ro or Ro and La) and circulating immune complexes were frequently present in patients with subacute cutaneous lupus erythematosus, whereas rheumatoid factor and anti-lymphocyte, anti-DNA, anti-nRNP, and anti-Sm antibodies were found less frequently. Patients having annular skin lesions represented a particularly homogeneous subgroup in which there was a striking concordance of anti-Ro antibodies and the HLA-DR3 phenotype. These studies clearly establish that the presence of these lesions can serve as a cutaneous marker for a distinct subset of patients with lupus erythematosus who share similar clinical, serologic, and genetic features.

Pemphigus vulgaris (PV) is a cutaneous autoimmune disease characterized by blister formation in the suprabasilar layers of skin and mucosae and anti-desmoglein-3 (Dsg3) autoantibodies bound to the surface of lesional keratinocytes and circulating in the serum of patients. This disease can be reproduced in neonatal mice by passive transfer of patients' IgG, indicating that humoral immunity plays an important role in the pathogenesis of PV. Currently, the role of T lymphocytes in the development of PV is not clear. Here, we report that three immunoreactive segments of the ectodomain of Dsg3 specifically induced proliferation of T cells from PV patients. We found that T lymphocytes from 13 out of 14 patients responded to at least one of three Dsg3 peptides. T cells from controls and other patient groups did not respond to these Dsg3 peptides. The major T cell population stimulated by these Dsg3 peptides was CD4 positive. Dsg3-specific T cell lines and clones were developed and were shown to express a CD4 positive memory T cell phenotype. Upon stimulation, these cell lines and clones secreted a Th2-like cytokine profile. The Dsg3 responses of these T cells were restricted to HLA-DR, and not -DQ and -DP, of the major histocompatibility complex. This information will help to elucidate the cellular immune abnormalities leading to production of pathogenic IgG autoantibodies in patients with PV. ( J. Clin. Invest. 1997. 99:31-40.)