Preliminary evidence of immune function modulation by thyroid hormones in healthy men and women aged 55–70 years

Abstract

A reciprocal relationship between the endocrine and immune system has been demonstrated under pathophysiological conditions. However, few studies have assessed the relationship between thyroid hormones and immune function in apparently healthy individuals. Therefore, to clarify our understanding of normal physiological endocrine-immune interactions this study aimed to examine the interrelationships between thyroid hormones and immunity in healthy individuals. Total triiodothyronine (T 3 ), total thyroxine (T 4 ) and markers of immune status were assessed in 93 free-living and apparently healthy individuals aged 55-70 years. T 3 and T 4 concentrations were determined by commercially available kits. Immune status was assessed using flow cytometry and biochemical markers. Statistical analysis was performed by partial correlation, controlling for age. Thyroid hormone concentration was positively associated with markers of inflammation (P%0 . 05), natural killer-like T cells (P%0 . 001), expression of interleukin-6 (IL6) by activated monocytes (P%0 . 05); percentage expression of memory T-lymphocytes (P%0 . 01), memory T-helper lymphocytes (P%0 . 05) and memory T-cytotoxic lymphocytes (P%0 . 05), and higher IL2 receptor density on CD3CT-lymphocytes (P%0 . 05). Thyroid hormone concentration was inversely associated with early lymphocyte apoptosis (P%0 . 05) and the ratio of naïve-to memory T-cytotoxic lymphocytes (P%0 . 05). The current study provides preliminary evidence of a role for T 3 and T 4 , within normal physiological ranges, in the maintenance of lymphocyte subpopulations, and in mediating the inflammatory response. In conclusion, these findings highlight the potential implications of altered thyroid function in older individuals and the importance of future research examining thyroid-immune interactions.

Hyperthyroid state orin vitrothyroxine treatment modulates TH1/TH2 responses during exposure to HSV-1 antigens

“…In 1973, it was reported that removal of the thyroid gland leads to significant reduction in peripheral lymphocytes, impaired humoral immunity, and reduced sensitivity of lymphocytes to mitogen (Fabris, 1973). Available data from several lines of in vivo and in vitro studies show that functions of almost all immune system cells, including monocytes, thymocytes, lymphocytes, natural killer (NK) cells, and splenocytes, are affected by THs (Csaba et al, 1977;Hodkinson et al, 2009;Mascanfroni et al, 2008;Savino et al, 1990). Tang & Kaptein (1989) were perhaps the first to show that alterations in serum levels of THs modulate host defense against viral infection.…”

Immune responses in the thyroid cancer microenvironment: making immunotherapy a possible mission

“…Moreover, physiological levels of T 3 were demonstrated to induce the maturation of murine DCs (Mascanfroni et al 2008). Similarly, T 4 was found to be associated with higher concentrations of complement proteins and also higher neutrophil counts (Hodkinson et al 2009). T 4 concentration was also inversely correlated with the ratio of naïve to memory cytotoxic T cells (Hodkinson et al 2009).…”

“…Similarly, T 4 was found to be associated with higher concentrations of complement proteins and also higher neutrophil counts (Hodkinson et al 2009). T 4 concentration was also inversely correlated with the ratio of naïve to memory cytotoxic T cells (Hodkinson et al 2009). Taken together, these results suggest that higher concentrations of thyroid hormones could enhance innate and adaptive immunity, via maintenance of specific subsets and increased responsiveness to immune stimuli (Hodkinson et al 2009).…”

“…For example, B cell development was shown to be suppressed in thyroid hormone-deficient mice (Foster et al 1999). Also, high concentrations of T 3 were associated with an increase in the amount of complement proteins and the number and phagocytic activity of monocytes (Hodkinson et al 2009). Moreover, physiological levels of T 3 were demonstrated to induce the maturation of murine DCs (Mascanfroni et al 2008).…”

Pregnancy Outcome in Euthyroid Women with Anti-Thyroid Peroxidase Antibodies

“…Although many types of antithyroid antibodies have been described, the most common is the group of antibodies directed against various parts of the thyroid peroxidase molecule [24][25][26]. Most pregnant women with abnormally elevated serum levels of thyroid peroxidase antibodies are clinically and biochemically euthyroid, but they may be at increased risk of spontaneous abortion, and preterm delivery and other pregnancy complications [11,27].…”