Systemic lupus erythematosus, rheumatoid arthritis and HLA phenotypes in Jamaicans

The HLA phenotypes were investigated in 30 Jamaican patients with systemic lupus erythematosus (SLE), 30 with rheumatoid arthritis (RA) an d forty healthy controls. HLA phenotypes were determined by the microcytotoxicity technique, using commercially prepared typing trays. In this study, the HLA phenotypic associations with SLE (HLA-B14, RR 4.3: HLA-A28, RR 4.3) were not statiscally significant. However, a statistically significant lack of HLA-A9 (p<0.01;CP<0.1) was observed in SLE patients compared to healthy controls. In RA patients, a statistically significant associations was noted with HLA-A2 (RR5.1; CP<0.01). No HLA class 11 associations were noted with SLE. Class 11 associations with RA did not achieve statistical significance but included those previously established in other populations. The preliminary data obtained from this study indicate differences in the patterns of HLA phenotypes in Jamaican patients with SLE and RA compared to those observed in such patients elsewhere. Further studies involving larger groups of patients and typing at the serological, cellular and molecular levels are clearly warranted

Seroprevalence of autoantibodies in selected and unselected populations in Jamaica

Various serological techniques were used to investigate the prevalence and distribution of autoantibodies in healthy Jamaicans and patients with autoimmune and non-autoimmune disease. Low concentrations of autoantibodies were found in healthy Jamaicans, including thyroid (1.5 per cent ), gastric parietal cell (1.4 per cent ) and smooth muscle (11.3 per cent ). There was no significant age or sex predominance in the distribution of autoantibodies in the healthy population though autoimmune disease was more prevalent in females. Serological overlaps occurred but the comparative distributions and concentrations of autoantibodies in patients with autoimmune disease and non-autoimmune disease, and health subjects indicate that currently available methods of autoantibody determination may be used successfully in diagnosis in Jamaica. Failure to detect circulating pancreatic islet cell antibodies in insulin-dependent diabetic patients as well as in healthy Jamaicans questions the pathogenicity of these antibodies and diminished their diagnostic usefulness in this population.