HL-A 27 and arthropathies associated with ulcerative colitis and psoriasis

HLA-B27 and frozen shoulder

Histocompatibility antigens were determined in 38 patients with frozen shoulder and 216 normal blood-donors. HLA-B27 was significantly more common in patients with frozen shoulder (42%) than in the controls (10%). The distribution of the other 19 histocompatibility antigens was similar in the patient and control groups. This result may be associated with the suggested immunological pathogenesis of the condition.

Periarticular uptake of 99mtechnetium diphosphonate in psoriatics: correlation with cutaneous activity

The periarticular uptake of 99mtechnetium-labeled diphosphonate (99mTcDp) was compared in 12 patients hospitalized for psoriasis and in 12 hospitalized for other dermatoses not associated with arthropathy. The 12 patients with psoriasis had recent onset disease of less than 5 years duration; neither group had historical or clinical evidence of arthritis. All psoriatics had markedly abnormal scans with symmetrically increased periarticular uptake about the imaged joints. None of the controls had similar findings. In 4 patients scanned with 99mtechnetium-pertechnetate within 24 hours of their 99mTcDP scan, no evidence of inflammatory synovitis was found. Three of these patients were serially imaged with 99mTcDP at intervals of 2 weeks to 3 months after their initial study, when obvious clinical improvement in their psoriasis was apparent. Improvement in the radionuclide joint images was demonstrated in some of the patients, but none reverted to normal during the study period. In light of recent evidence for the preferential binding of 99mTcDP to immature collagen, it is suggested that psoriasis may represent a generalized, but uncharacterized, collagen disorder present in bone as well as skin, linking the cutaneous disease with the potential for arthropathy.

HLA-B27 and modified bone formation

Of the many associations between histocompatibility antigens and human diseases a prominent one is that between HLA-B27 and inflammatory arthropathies. Hypotheses to explain this association include the B27 gene being linked to a specific immune-response gene required for disease expression and the B27 antigen acting via molecular mimicry with a microorganism or as a microorganism receptor. Alternatively, the HLA-B27 gene might be closely related to a gene which influences bone formation. The finding of a significant association between B27 and Forestier's disease, a disease characterised by abundant new bone formation, supports such a hypothesis.

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.

Ankylosing spondylitis in a large kindred: clinical and genetic studies

In a kindred of 66 members spanning four generations, seven cases of ankylosing spondylitis (AS) HAVE BEEN FOUND. Four of these were in a single sibship of 13. AS was associated with HL-A27 in three of the four involved siblings, but close linkage was shown to be unlikely. Knowledge of HL-A genotype has made possible informed counseling for younger members of the sibship of 13, some of whom, as teenagers, already have back pain.

HL-A W27 in psoriatic arthropathy

Forty subjects with psoriatic arthritis (PA) underwent HL-A tissue typing. HL-A W27 was significantly increased in psoriatic spondylitis (35%), whereas statistical significance was not reached in patients with peripheral arthritis alone, although W27 was present in a frequency greater than in controls. Psoriatic spondylitis (often asymptomatic) occurred in 57% (23 of 40) of our PA patients. Of interest, psoriatic spondylitis was more often W27 negative than W27 positive; nevertheless, W27-positive and W27-negative spondylitis was clinically and radiographically indistinguishable except that W27-positive disease occurred exclusively in males and the duration of the psoriasis.