Thyroid peroxidase antibody positivity is associated with symptomatic distress in patients with Hashimoto's thyroiditis.

Previous studies suggest impairments of physical, mental, and psychic well-being in patients with Hashimoto's thyroiditis (HT), but these impairments have been shown to be independent of thyroid dysfunction. In 64 euthyroid patients with HT, symptomatic distress was assessed with the Symptom Checklist-90-Revised (SCL-90-R), a 90-item multidimensional self-report symptom inventory using a 5-point rating scale. In a subgroup of patients, endocrine testing 3 years prior to the current investigation was available. Anti-thyroid peroxidase antibodies (TPO-Abs) were associated with the three SCL-90-R global indices Global Severity Index (GSI), Positive Symptom Distress Index (PSDI), and Positive Symptom Total (PST) as well as with somatization and obsessive-compulsive symptoms after adjustment for age, gender, and thyroid function as assessed by TSH levels (all p<0.05). HT patients positive for TPO-Abs showed poorer results in the three SCL-90-R global indices as well as in the three domains: somatization, obsessive-compulsive symptoms, and depression (all p≤0.02), though the aforementioned associations did not withstand sequential Bonferroni correction for multiple testing. In contrast, TPO-Abs positivity, defined as TPO-Abs >100 IU/l, significantly predicted poorer psychosocial well-being in all of the three SCL-90-R global indices after three years, even after correction (all p≤0.02). In conclusion, high TPO-Abs are associated with poor physical and psychological well-being and appear to predict future health perception in HT patients.

Increased prevalence of antibodies to central nervous system tissue and gangliosides in Hashimoto's thyroiditis compared to other thyroid illnesses.

BACKGROUND: Previous studies point to central nervous system (CNS) alterations in euthyroid patients with Hashimoto's thyroiditis (HT). The aim of the present study was to investigate the prevalence and clinical significance of antibodies (Abs) against CNS tissue and gangliosides in female patients with HT compared to patients with other non-autoimmune thyroid disorders, comprising diffuse or nodular goitre and thyroid surgery for goitre. METHODS: 58 HT patients (mean age: 46+/-17 years) and 89 patients with other thyroid disorders (mean age: 51+/-15 years) were recruited consecutively from our endocrine outpatient clinic. Serum Abs against CNS tissue and gangliosides were determined using an enzyme-linked immunosorbent assay (ELISA). In a subgroup of 23 HT patients, neurocognitive function was studied using established neuropsychological tests. RESULTS: In HT patients, the prevalence of serum anti-ganglioside-Abs and anti-CNS-Abs were significantly higher compared to patients with other thyroid disorders (p<0.05 and p<0.005, respectively). In both cases, the number of Ab-positive HT patients was twice that of Ab-positive controls. Reactivity of IgM-Abs to gangliosides and IgG-Abs to CNS tissue was significantly higher in HT patients than in controls (p<0.05 and p<0.01, respectively). However, prevalence and reactivity of Abs to gangliosides and CNS tissue were associated neither with the prevalence of depression nor with impairment of neurocognitive function in HT patients. CONCLUSION: Ab reactivity towards CNS tissue and gangliosides is markedly enhanced in patients with HT as compared to patients with other thyroid disorders. Whether these Abs could be of prognostic value to evaluate the risk of future neurocognitive impairment has to be investigated in longitudinal studies.

Increased occurrence of weaknesses in attention testing in patients with Hashimoto's thyroiditis compared to patients with other thyroid illnesses.

Previous studies suggest disturbances of the central nervous system (CNS) in patients with Hashimoto's thyroiditis (HT), independently of thyroid function disorders. In the present prospective study, neuropsychological testing was performed for the first time in 26 euthyroid patients with HT compared to 25 euthyroid patients undergoing hormonal treatment for goitre or after thyroid surgery. We investigated executive function, attention, visual and verbal memory as well as acoustic working memory with established neuropsychological tests and detected no significant differences between the two groups. In addition, test results were expressed as z-score which is defined as the deviation of an individual's value from the mean value of a reference population, divided by the standard deviation of the reference population. Thereby, we found significantly more HT patients with a z-score of less than -1.5 in the d2 test than in the control group (total score I, HT vs. control group: 10 vs. 3, p=0.0302; total score II, HT vs. control group: 11 vs. 1, p=0.0013). The d2 test, which measures processing speed, rule compliance, and quality of performance, allows for a neuropsychological estimation of individual attention performance. HT patients with results below the normal range in the d2 attention test showed a significant increased mean value of anti-thyroid peroxidase antibodies compared to HT patients with normal test results (371.4+/-187.2IU/l vs. 69.3+/-28.7IU/l, p<0.05). In conclusion, our results point to subtle brain dysfunction in a subgroup of patients with HT even in euthyroid state. This could either be due to an association with an unknown autoimmune disorder affecting the CNS or a pathogenetic role of thyroid antibodies themselves.