Ankylosing spondylitis and the major histocompatibility system

The frequency of HLA-Dw1 determinant in subacute (de Quervain's) thyroiditis

Investigation of a group of 23 patients suffering from subacute (de Quervain's) thyroiditis for the frequency of the HLA-Dw1 determinant showed this determinatant to be more frequent--30.4%--compared to its frequency in a healthy population--19.1%. The finding is not statistically significant.

HLA class II antigens (DR, DQ loci) and peripheral arthritis in ankylosing spondylitis

Fifty one patients with ankylosing spondylitis (AS) were typed for HLA-A, B, C, DR, and DQ antigens. The antigen frequencies were compared with those of a normal population and with a B27 positive control group. All but one of the patients with AS were HLA-B27 positive. A positive linkage disequilibrium between Cw1, Cw2, DR1, and the B27 antigen was observed. Patients with AS showed a significant increase in DQw2 antigen compared with the B27 positive control group. No differences in antigenic frequencies were observed in patients having peripheral arthritis and patients with only axial involvement. Seven out of nine patients (78%) with an erosive peripheral arthritis were DR7 positive, suggesting that DR7 or genes closely linked could be related with a more aggressive peripheral joint involvement in patients with AS.

Reactive arthritis

Reactive arthritis is a rare complication of certain infections. The similar features and HLA associations with the seronegative arthropathies have raised the possibility that the latter may be forms of reactive arthritis. This review describes the clinical and epidemiological features, and the recent advances in our understanding of the underlying pathogenesis of reactive arthritis.

HLA-D locus typing in ankylosing spondylitis and Reiter's syndrome

HLA-D typing of 44 patients with ankylosing spondylitis (AS) and 31 patients with Reiter's syndrome (RS) did not show increased frequency of any particular Dw allele in either population of patients as compared to controls. Such studies also allowed each patient's general response to be compared with other general responses within each experiment. Contrary to reports of diminished lymphocyte responses in AS patients, hyperresponsiveness in both AS and RS patients was found.

Diminished mixed lymphocyte response in ankylosing spondylitis

A diminished mixed lymphocyte response was reported by Nikbin et al. (1976) among patients with ankylosing spondylitis, their asymptomatic relatives and also normal controls carrying the B27 antigen. In the present communication, the responses in 48 ankylosing spondylitis patients and 45 controls were examined in mixed lymphocyte cultures tested against a 'standard stimulator' made up of pooled lymphocytes. A significantly diminished response is confirmed among the ankylosing spondylitis patients, but not in the control group carrying the B27 antigen. The diminished mixed lymphocyte response therefore appears to be more directly associated with the disease than with the B27 antigen, and possibly represents a specific T-cell defect associated with the pathogenesis of the disease.

HLA antigens in females with ankylosing spondylitis and other forms of seronegative rheumatic diseases

A total of 222 female patients with seronegative rheumatic diseases were investigated by sacroiliac joint X-ray and HLA-A, B and Ctyped. The frequency of the B27 antigen was significantly increased in the following groups: definite pelvospondylitis (26 patients and relative risk (RR) = 99), possible pelvospondylitis (20 patients, RR=4.5), definite sacroiliitis (14 patients, RR-20.1) and uroarthritis (8 patients). When 24 B27 negative patients from these B27 associated diseases were analysed, significantly increased frequencies of the BW22 (RR=16.7) and CW1 (RR=14.4) antigens were found. There were no significantly deviating HLA frequencies in the following diagnostic groups: clinical sacroiliitis (20 patients), polyarthritis with clinically silent sacroiliitis (12 patients), polyarthritis without sacroiliitis (47 patients), arthralgia preceded by beta-streptococcal infection (17 patients), other arthralgia (33 patients), osteo-arthritis (13 patients) and other arthritis (12 patients).

Histocompatibility antigens and other genetic markers in ankylosing spondylitis and inflammatory bowel diseases

Of 118 Dutch patients suffering from ankylosing spondylitis (AS) 81-4% were found to be positive for the HLA antigen B27. The B27 frequency proved to be significantly higher in patients in whom the disease had an early onset. In addition to B27, another HLA antigen may be associated with AS; the antigen Bw 16 was found to be significantly increased in B27 negative AS patients. HLA phenotype frequencies were also determined in 109 patients with idiopathic inflammatory bwel disease (IBD). In fifty-eight ulcerative colitis (UC) patients a raised incidence of A 11 was noticed. In fifty-one patients with Crohn's disease (CD) the antigen B18 showed an increased frequency. Both deviations were statistically significant. In thirty-nine patients suffering from both AS and IBD 50% proved to be B27 positive, which is significantly diffrent from B27 frequency in patients with AS alone. In the B27 negative patients with AS and IBD and increased frequency of Bw16 was also shown.

Homozygosity for HLA-B27. Impact on rheumatic disease expression in two families

The effect of homozygosity for HLA-B27 on the clinical expression of rheumatic disease was studied in two families. The 1 homozygous patient in each of two families demonstrated extraordinarily severe peripheral and axial arthritis compared to other affected heterozygous relatives. In addition, predominant peripheral or axial disease appeared to segregate with different B27 haplotypes. The 2 homozygous patients were not homozygous at the hla-a,c, or D loci.

HLA-antigen b27 in cases with joint affections in an outbreak of salmonellosis

An outbreak of infection with Salmonella typhi murium occurred in southern Sweden in the summer of 1974. About 330 persons were infected; 91 were hospitalized. 13 of the 91 patients (9 men and 4 women) had symptoms of aseptical polyarthritis. The 13 patients with arthritis were HLA typed with a standard microlymphocytotoxicity test. 13 salmonellosis patients from the same epidemic but without arthritis and 446 healthy blood donors served as controls. Nine (69%) of the 13 patients with arthritis had HLA-B27 compared to 1 (8%) of the control patients and 44 (10%) of the blood donors. The observed association between HLA antigen B27 and reactive arthropathy following salmonella infection could be due to a function of a disease predisposing gene closely linked to HLA-B27.

The HLA linkage group and disease susceptibility

The HLA linkage group, located on chromosome 6, is composed of serologically defined (SD-) loci (HLA-A, -B and -C) and of a MLC (= mixed lymphocyte culture-) or lymphocyte defined (LD-) locus (HLA-D). Different alleles of these loci are linked together as well as with loci for the synthesis of some complement components and the properdin factor B (= Bf-system) by strong positive linkage disequilibria (gametic association). The indication of a HLA linked genetic control of immunoresponsiveness makes the HLA system one of the biologically most important immunogenetic systems in man. The associations, found between single HLA determinants and diseases, can be explained in different ways, but may contribute to a better understanding of the etiopathogenesis of diseases and of the biological role of the HLA linkage group.

Typing for MLC determinants: methods and applications

MLC typing of random individuals can be performed using a panel of inactivated HLA-D homozygous cells. Eight different HLA-D specificities are now internationally accepted. The evaluation of the results must take into account both the general responding capacity of the cell to be typed and the general stimulating capacity of the typing cells. An evaluation based on the 75th percentile is discussed in detail and some pitfalls are mentioned. Furthermore a description is given of primed lymphocyte typing (PLT), where cells primed in ordinary MLC cultures to one HLA-D determinant have the ability to respond in an accelerated way to similar HLA-D antigens when re-exposed to such cells in secondary cultures. In our experiments, an excellent correlation is found between these two ways of MLC typing provided that the cells used for priming are well characterized (i.e. HLA-D homozygous cells). Finally, some clinical applications of MLC typing are described, especially in connection with transplantation and association between HLA and various diseases.

HL-A8 and LD-8a in patients with myasthenia gravis

The frequency of HL-A8 in myasthenia gravis is markedly increased in women (60-80%) but not in men. The MLC determinant, LD-8a, is frequently associated with HL-A8. Of the 37 female MS patients, 15 were LD-8a positive (41%), whereas of the males only one of seven was LD-8a positive. The frequency of HL-A8 was 68% in women and 29% in men with the disease. We therefore conclude that the gene which is responsible for the increased susceptibility to myasthenia gravis in women and which is present in the MHS region, is more closely linked to the SD-2 than to the LD-1 locus.

Segregation of HL-A27 and ankylosing spondylitis in an informative kindred

A family with high prevalence of ankylosing spondylitis (A.S.) was investigated for the presence of HL-A27. In this family, classical A.S. occurred in five subjects and possible A.S. in two out of 64 members examined. In all seven cases, HL-A27 was present. The study of the segregation of A.S. and HL-A27 in this kindred demonstrates that more than one gene is responsible for the expression of A.S., that the homozygous state for the HL-A27 gene may lead to the occurrence of A.S., and that possibly a simple genetic explanation accounts for the simultaneous transmission of HL-A27 and A.S.

Studies on the major histocompatibility system in patients with ankylosing spondylitis

One hundred % of 66 patients with pelvospondylitis were found to have HL-A27, whereas the frequency of the antigen in 60 patients with sacroiliitis was 70 %. The difference in frequency of HL-A27 between the two patient groups is statistically highly significant. This implies that tissue typing could be of clinical importance for a prognostic evaluation of patients with sacroiliitis. Studies in families with several HL-A/MLC identical sibs indicated a relatively low penetrance of disease in those carrying the gene for increased susceptibility to development of AS. No association of AS to particular MLC alleles was found either in families or in several SD-2 identical AS patients.