The prevalence of histocompatibility antigen HLA-Cw6 was 72.7% in twenty-two patients with the guttate form and 45.9% in thirty-seven patients with the vulgaris form of psoriasis; the difference between these figures and the prevalence (7.4%) in 462 healthy blood donors in Finland is highly significant. The previously observed excess of several HLA-B locus genes might be secondary to their close linkage with the Cw6 gene. Hereditary factors appear more important in the guttate than in the vulgaris form of psoriasis.

No abstract

An analysis of 160 patients with Reiter's disease, 144 with yersinia arthritis, and 9 with salmonella arthritis was performed. Complete or incomplete Reiter's syndrome was observed in one‐third of the patients with yersinia arthritis and in most of those with salmonella arthritis. During the followup period, chronic back pain and joint symptoms were frequent in all the patient groups. Patients who were HLA—B27 positive had a more severe acute disease (more frequent back pain, urologic symptoms, mucocutaneous manifestations, and a longer duration of the disease) and more frequent chronic back pain and sacroiliitis.

The histocompatibility antigen HL‐A 27 was identified in 43 of 49 patients with yersinia arthritis and in 36 of 40 patients with Reiter's disease, compared with 3 of 20 patients with yersinia infection without arthritis and 14% of the normal Finnish population. HL‐A 2 occurred in patients with reactive arthritis in the same high frequency as did HL‐A 27, but this antigen is present in 55% of Finns. HL‐A 27 negative patients usually had a mild or somewhat atypical disease.

No abstract

IgA antibodies to Yersinia enterocolitica were demonstrated in the sera of 13 patients with severe versinia arthritis who were studied six to eight months after an acute infection with Yersinia. Four of the patients were monitored for two to three years, and they continued to demonstrate these antibodies. Only one of 12 control patients (individuals with yersinia infection without arthritis) had IgA antibodies specific to Yersinia six to eight months after the acute infection. The persistence of IgG antibodies was also in direct correlation to the occurrence of arthritis, but not as clearly as was the persistence of IgA antibodies. Antibodies of the IgM class persisted in most cases for only one to three months and always disappeared during the first six months after the onset of the infection. Thus, the demonstration of IgA antibodies to Yersinia is important in the diagnosis of yersinia arthritis, and the occurrence of IgM antibodies indicates a recently acquired infection with Yersinia.

No abstract

SUMMARY HLA antigens and various aspects of atopy were studied in 42 Finnish children and adolescents with coeliac disease, and the results were compared with findings of recent population studies. The HLA associations were as expected: relative risks for coeliac disease in individuals with HLA-B8, DR3, and DR7 were 8.0, 18-6, and 15.0, respectively. Children with coeliac disease were significantly more often atopic than unselected schoolchildren. Atopy was significantly more frequent and the onset of coeliac disease later for B8/DR3-patients than B8/DR3+ patients. There was no obvious relation between DR7 and atopy.