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The frequencies of 30 HL-A antigens were studied in an Indonesian population of 95 individuals from the city of Jakarta. The antigens HL-A9, or more precisely W24, and HL-A11 (first series) and W15 (second series) occurred with high frequencies, whereas HL-A8, W14 and W22 were completely absent. These results are consistent with previous reports of HL-A typing in South East Asian populations.

Sera from 47 patients immunized mainly by multiple transfusions during haemodialysis were studied by the lymphocytotoxicity test (LCT) and the platelet complement fixation test (PICF). The HL-A specificities of the observed antibodies were compared with the HL-A antigens present in the immunized subjects. The inhibition of the production of antibodies against certain antigens in the presence of cross reacting antigens in the immunized individuals was studied by a method using “Bayes’ theorem”. This inhibition was only partial for the antibodies detected by LCT in contrast to those found by PICF. The comparison of both techniques lead to the conclusion that this type of inhibition did not completely prevent the production of antibodies against a cross reacting antigen but it decreased the frequency and intensity of the response against the antigen.

In 94 children suffering from cystic fibrosis, no abnormal frequencies of HLA markers of the A and B locus were observed in comparison with the distribution of these antigens in control series. Furthermore, the HLA genotypes of seven pairs of diseased sibs are incompatible with the hypothesis of a closed linkage between CF--an autosomal recessive transmitted disease--and HLA.

Association between HLA and multiple sclerosis (MS) was investigated at the population level on 100 MS patients genotyped for HLA-A, B, C, DR and Bf, Glo, and on 155 patients phenotyped for the same HLA antigens. Association between MS and DR2 was clearly confirmed, although its strength is rather weak. No other genetic marker could be related to the disease, no haplotype nor any allelic combination could be recognized as MS specific, and antigen genotype frequencies among the diseased could not ascertain the mode of inheritance, although dominance is very likely. Computer analysis between HLA, Bf, Glo and age of the patient, sex, age of onset and evolution of MS, impairment indexes, titres of anti-DNA and anti-measles antibodies in CSF did not show any interaction. Twenty sib pairs and two trios of MS were also studied; they showed no significant distortion with the random distribution of haplotypes. DR2 gene frequency, however, was significantly higher in sib pairs showing one or two haplotypes than in HLA different affected siblings. Three crossing-overs were identified which suggest where the HLA-linked MS susceptibility (MSS) gene could be located within the HLA segment, while other epistatic MSS genes or environmental factors are likely to be important.

Linkage analysis was performed between HLA and Maturity-Onset Type Diabetes of the Young (MODY) in 9 families. No significant positive lod scores were found. A linkage was excluded at a value of the recombination fraction equal to zero assuming a low MODY gene frequency.

One hundred fifty-five healthy nonagenarians, 45 men and 100 women, all French Caucasians, were phenotyped for alleles of the A, B, C, DR loci of the HLA complex. The observed HLA antigen frequencies were compared to those of a control series of 133 males and 179 females whose ages ranged from 10 to 50 years. When comparing the total young and elderly series, no significant differences were observed with respect to HLA antigen distribution or heterozygosity at any of the loci. When taking sex difference into account, however, an excess of the Cw1 antigen was found in the group of elderly females (p less than 0.001) and an excess of the Cw7 antigen in the group of elderly males (p less than 0.001). Of particular significance was the fact that Cw7 belonged in this instance to a phenotypic combination (and most probably to the corresponding haplotype) A1/Cw7/B8/DR3 which was found significantly increased in male nonagenarians (p less than 0.001). These results support the hypothesis that certain HLA haplotypes are associated with survival advantage.