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Sequencing analysis of exons 1-3 of the human leukocyte antigen (HLA)-C gene showed a novel allele, HLA-Cw*0617. While the amino acid sequence is identical with the HLA-Cw*060201 allele, the leader peptide differs in three amino acids.

A proposal for a standardized nomenclature for human leukocyte antigen (HLA) microsatellites is presented. It provides recommendations for Microsatellites as regards to locus name, primer names, and denominations for alleles.

A new human leukocyte allele HLA-B*8102 has been identified in a cell provided by the UCLA International Cell Exchange scheme. The nucleotide sequences of exons 2 and 3 of the new allele are identical with HLA-B*8101. Four nucleotide differences, however, are observed in exon 1, three of them representing non-synonymous base changes.

The microheterogeneity of the tetranucleotide repeat locus C2_4_4 situated in the HLA class I region (6p21.3) was investigated by sequencing 50 alleles in an Austrian population sample of 240 unrelated Caucasoid individuals. Several different sequences were found in alleles of the same length. Analysis of the associations between the sequenced C2_4_4 alleles and HLA class I showed a strong linkage disequilibrium between the C2_4_4*9 sequence variants and two different HLA class I haplotypes, as well as between the most common *17 sequence and one HLA-ABC haplotype. No clear cut association could be observed in C2_4_4*16 and *18. The results of this study demonstrate that the exclusive use of microsatellite polymorphisms for the definition of HLA haplotypes is generally not possible.

We have established a ligation based typing method to detect HLA-B*27 alleles at the DNA level. The method requires amplification of exon 2 of the HLA-B locus from genomic DNA by the polymerase catalyzed chain reaction (PCR) using group specific primers. An aliquot of the PCR amplification product, heat stable ligase and a pair of oligonucleotide probes, designed to hybridize adjacently to HLA-B*27 specific sequences of the amplified DNA are subsequently thermocycled. If the probes are perfectly complementary they become ligated otherwise they stay separated. The ligation of probes can be detected through their different labels by an enzyme linked immunosorbent assay (ELISA). Ligation based detection of beta-actin sequences which have been co-amplified serves as positive control for each PCR reaction. We observed complete concordance when typing 76 HLA-B*27 positive and 107 HLA-B*27 negative individuals either by serology or by the ligation based approach. We conclude that ligation based typing is a reliable tool for the DNA based detection of HLA-B*27 alleles. The procedure allows automation to a large extent and should be easily applicable to the typing of other HLA-class I alleles.

Fifty-four thyrotoxic patients (23 with and 31 without endocrine ophthalmopathy EOP) were HLA typed for A, B, and C locus antigens. The frequency of this third locus antigen CW3 was found to be significantly increased in patients with EOP compared with those thyrotoxic patients without EOP. These findings point to a possible genetic heterogeneity in thyrotoxic patients with or without EOP. HLA B8 was observed in only 10 of the 54 patients studied, which is not in accordance with the previously reported statistically significant increased frequency of this B locus antigen in thyrotoxic patients.

In a joint study 109 unrelated HLA-B14 positive individuals were subtyped for the provisional splits 14.1 and 14.2 respectively, based on sera of the 7th and 8th Histocompatibility Workshops. Sixty-eight of these donors as well as 23 families were also typed for DR antigens. Earlier findings concerning a linkage disequilibrium B14.1/Aw32 and B14.2/Aw33 were confirmed. In addition a highly significant association B14.1/DR7 as well as a less striking one for B14.2/DR1 were observed. These findings contribute new arguments for the partition of the B14 antigen.

An LD defined split of HLA-DR2, different from HLA-Dw2, Dw12 and DB9, is observed in the Austrian population. The narrow HLA-D specificity, defined by a new Austrian Homozygous Typing Cell (HTC), a primed lymphocyte (PLT) cell line and a PLT clone, is tentatively termed HLA-D"WH". Investigation of three informative families shows that HLA-D"WH" segregated together with HLA-DR2. In one family, even an individual heterozygous for HLA-DR2/Dw2 and HLA-DR2/D"WH" can be identified. A panel study including 90 non-related Austrians shows that HLA-D"WH" occurring in 6.7% of the whole panel, that is in 20% of the HLA-DR2 positive panel members, is completely included in HLA-DR2. HLA-D"WH" might be comparable to other LD specificities related to HLA-DR2, "MN2", "FJO", "AZH" or "GEN".

A panel of 120 HLA-A, -B, -C and -DR typed Austrians has been typed for HLA-D by the use of 26 Homozygous Typing Cells (HTC). The new Austrian HTC, partly defined by the 9th International Histocompatibility Workshop (9WS), partly by a checkerboard experiment with internationally well defined reference HTC, type for HLA-Dw1 to -Dw7 and an obviously new, so far unknown HLA-DR2 related HLA-D determinant. Associations of HLA-DR and HLA-D antigens in Austria and their frequencies are determined. Antigen frequencies in Austria are compared to frequencies in other Caucasoid populations.