Primary and secondary autoimmune thyroiditis in rheumatoid patients
V. Odin, V. Tyrenko, E. Tzygan, M. Blohin & N. Avtandilashvily
Aim: Studying of features autoimmune thyroiditis associated with rheumatoid arthritis (AIT/RA).
Methods and materials: Twenty-nine women with AIT/RA were examined. Study design included: special protocol of anamnesis, sonography of thyroid gland, evaluation of thyroglobulin antibodies (Tg-Ab), thyreoperoxidase antibodies (TPO-Ab), the thyroid hormones (T3, T4) and TSH in serum. Two groups of patients have been allocated: I group (n=21) persons at whom RA debuted after debut AIT (primary AIT/RA), II group (n=8) persons at whom debuted the first RA with the subsequent debut AIT (secondary AIT/RA).
Result: The persons with primary AIT/RA were majority 72%. The age of a debut primary AIT/RA was at 44.3±1.2 years, while secondary AIT/RA debut 55.4±1.6 years (P<0.05). Thus in II group of 88% of patients had debut of AIT in the postmenopausal period (mean age of a menopause 51.2±1.2 years), while the majority of patients of I group 86% in the menstrual period. Thyroid volume exceeded normal values at 38% of patients of I group and at 25% of patients in II group. Hypothyroidism has been revealed at 90% of patients of I group and at 75% of patients of II group, in most cases was in subclinical grade. Cases of thyrotoxicosis were absent. Tg-Ab level in I group was considerable above, than in II (507.5±48 vs 272.5±57 IU/ml accord., P<0.05), TPO-Ab level also was above in I group (P<0.05).
Conclusions: Primary AIT/RA was observed much more often, than secondary AIT/RA and had debut on a late menstrual phase of ontogeny, while secondary AIT/RA had debut at on early postmenopausal period. Primary AIT/RA had antibodies level in higher concentration in comparison with secondary AIT/RA especially Tg-Ab level and had more often impairments of thyroid function mainly observed as a subclinical hypothyroidism.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.