Relationship between circulating cytokine levels and thyroid function following bone marrow transplantation

Abstract

Summary:The relation between thyroid hormone changes and cytokines in bone marrow transplantation (BMT) patients has not been studied. This prospective study was designed to determine the relation between thyroid hormones and cytokine levels after BMT and their effects on the mortality. We studied 80 patients undergoing allogeneic BMT. Serum thyroid hormone parameters and cytokine levels were measured before and serially during 6 months after BMT. Serum T 3 decreased to a nadir 3 weeks post-BMT and serum T 4 was lowest at 3 months post-BMT. Serum thyroid stimulating hormone (TSH) sharply decreased to a nadir at 1 week and recovered. Serum interleukin-6 increased for 2 weeks after BMT and declined thereafter. Serum tumor necrosis factor-a increased for 3 weeks after BMT and declined thereafter. After 3 weeks post-BMT, both cytokine levels were negatively correlated with serum T 3 and T 4 levels. A total of 29 patients died before 1 year post-BMT and 51 patients survived longer than 1 year. Those patients who died before 1 year post-BMT had significantly lower levels of T 4 at 3 weeks, 3 and 6 months than surviving patients. In conclusion, increased levels of serum IL-6 and TNF-a were negatively correlated with thyroid hormone concentrations in BMT recipients suggesting the role of these cytokines in euthyroid sick syndrome.

Guidelines for the Treatment of Hypothyroidism: Prepared by the American Thyroid Association Task Force on Thyroid Hormone Replacement

“…The non-thyroidal illness syndrome (NTIS) (also known as the sick euthyroid syndrome or the low T3 syndrome) occurs when patients with normal thyroid function become critically ill; in this setting, a progressive depression of the thyroid axis occurs such that circulating T3 decreases, followed by declines in serum TSH and/or T4, and then declines in FT4 in some sicker patients (592,593). In current practice, these patients are not treated with thyroid hormone replacement (see recommendation 22 regarding the NTIS).…”

Thyroid hormone: relevance to xenotransplantation

“…Furthermore, a relationship between low T3 and inflammation has been reported . Lee et al demonstrated that increased levels of serum IL‐6 and TNF‐α negatively correlated with thyroid hormone concentrations in transplant recipients, suggesting a role of these cytokines in ESS.…”

Evaluation of C‐reactive protein, interleukin‐6, and procalcitonin levels in allogeneic hematopoietic stem cell recipients

“…Numerous inflammatory markers in the peripheral blood of patients with TRC have been reported to be abnormal (12, 13). As there is considerable controversy about their clinical significance (14, 15), we conducted a large trial in allogeneic stem cell recipients to validate the diagnostic relevance of CRP, IL‐6 and PCT serum levels in the discrimination between different TRC.…”