THYROID-FUNCTION AND IMMUNE PROFILE IN RHEUMATOID-ARTHRITIS - A CONTROLLED-STUDY

The aim of our study was to determine the prevalence of thyroid dysfun ction and autoimmune abnormalities in rheumatoid arthritis (RA) and to further investigate the possible association between D-penicillamine and autoimmune thyroiditis. For this purpose, one hundred and one unse lected consecutive patients with RA and 70 age and sex matched control s were studied prospectively. Evaluation included a complete history a nd physical examination with special attention to symptoms suggestive of thyroid pathology, routine laboratory and serologic immune profile, plus determination of serum levels of thyroxine (T4), triiodothyronin e (T3), thyroid stimulating hormone (TSH), antibodies to thyroid perox idase (AbTPO) and TSH receptor antibodies (TRAB). Serum thyroxine bind ing globulin (TBG) was measured in all subjects with high thyroid horm one levels, whereas free T3 and T4 concentrations were determined in a ll individuals with abnormal T3, T4, TSH or TBG. Six patients with hyp erhyroidism, 3 with hypothyroidism and 1 with the euthyroid hyperthyro xinemia (EH) syndrome were found, whereas four of the controls had hyp erthyroidism. Thirteen patients and 6 controls had high AbTPO levels w hereas no one had high TRAB. No association was detected between thyro id abnormalities and any serologic RA finding. Furthermore, no correla tion between thyroid dysfunction and elevated AbTPO's was found. A rel atively high prevalence of thyroid dysfunction (9,9%) and subclinical autoimmune thyroiditis (12,9%), the latter indicated by elevated AbTPO 's, was found in our RA patients. These figures were higher than those in the control group (5,7% and 8,6% respectively), but the difference did not reach statistical significance. Of further interest may be ou r finding that, despite anecdotal reports blaming D-penicillamine for cases of autoimmune thyroiditis, the incidence of the latter was simil ar among recipients and nonrecipients of the drug. Similarly, TRAB wer e not detected in any patient treated with D-penicillamine.