Possible Relations Between Thyroid Function, Endothelium, and Kidney and Liver Function in Kidney Allograft Recipients

Exploring Thyroid Function after Kidney Transplantation: The Complex Interplay Unacknowledged in Post-Transplant Care

Background/Objectives: The interplay between thyroid function and kidney graft function following kidney transplantation remains incompletely understood. Thyroid disorders are more prevalent in kidney transplant recipients than in the general population and are associated with poorer outcomes. Methods: This prospective, single-center study was designed to estimate thyroid function (thyroid-stimulating hormone (TSH), triiodothyronine (T3), free triiodothyronine (FT3), thyroxine (T4), free thyroxine (FT4), as well as anti-thyroid peroxidase antibody (anti-TPO), anti-thyroglobulin antibody (anti-Tg), and thyroid-stimulating immunoglobulin (TSI)) and its influence on kidney graft function among a cohort of 23 kidney transplant recipients during a follow-up period of 12 months. Results: Significantly increased levels of T4 and T3 were observed 12 months post-transplantation, with FT3 levels increasing significantly after 6 months. The prevalence of immeasurably low anti-Tg antibodies rose during follow-up. Initially, 8% of patients showed positive TSI, which turned negative for all after 6 months. A statistically significant correlation was found between the initial TSH and the estimated glomerular filtration rate (eGFR) value 6 months after transplantation (p = 0.023). The graft function was stable. Proteinuria was statistically significantly lower 12 months after transplantation. Conclusions: Identifying additional risk factors, understanding their impact on kidney graft function, and recognizing cardiovascular comorbidities could enhance patient care. Notably, this study marks the first prospective investigation into thyroid function after kidney transplantation in Croatia, contributing valuable insights to the global understanding of this complex interplay.

Thyroid, Gonadal and Adrenal Dysfunction in Kidney Transplant Recipients: A Review for the Clinician

While chronic kidney disease-associated mineral and bone disorders (CKD-MBD) prevail in the endocrinological assessment of CKD patients, other endocrine abnormalities are usually overlooked. CKD is associated with significant thyroid, adrenal and gonadal dysfunction, while persistent and de novo endocrinological abnormalities are frequent among kidney transplant recipients (KTR). Low T3 levels prior to transplantation may help identify those at risk for delayed graft function and are often found in KTR. Thyroid surveillance after kidney transplantation should be considered due to structural anomalies that may occur. Despite the rapid recovery of gonadal hormonal secretion after renal transplantation, fertility is not completely restored. Testosterone may improve anemia and general symptoms in KTR with persistent hypogonadism. Female KTR may still experience abnormal uterine bleeding, for which estroprogestative administration may be beneficial. Glucocorticoid administration suppresses the hypothalamic-pituitary-adrenal axis in KTR, leading to metabolic syndrome. Patients should be informed about signs and symptoms of hypoadrenalism that may occur after glucocorticoid withdrawal, prompting adrenal function assessment. Clinicians should be more aware of the endocrine abnormalities experienced by their KTR patients, as these may significantly impact the quality of life. In clinical practice, awareness of the specific endocrine dysfunctions experienced by KTR patients ensures the correct management of these complications in a multidisciplinary team, while avoiding unnecessary treatment.

Boldenone undecylenate disrupts the immune system and induces autoimmune clinical hypothyroidism in rats: Vitamin C ameliorative effects

The present study was designed to evaluate the effects of boldenone undecylenate (BL) abuse alone and in combination with vitamin C (VC) on the immune responses and thyroid structure and function in rats. Thirty adult male Wistar rats were randomly divided into five equal groups and were subjected to various treatment regimens for eight weeks as follows: control group, vehicle control group, VC group orally received VC (120 mg/Kg BW/day), BL-treated group intramuscularly injected with BL (5 mg/kg BW, once/week), and BL+VC group received BL and VC. At the end of this experiment, blood and tissue samples (thyroid, thymus, and spleen) were subjected to hematological evaluation, biochemical analysis, histopathological, and immunohistochemical examinations. In comparison to controls, BL significantly increased the levels of serum proinflammatory interleukins (IL-1 β and IL-6), immunoglobulins (IgG and IgM), and complement 3 but reduced anti-inflammatory interleukin-10, lysosome, and nitric oxide. Besides, altered platelet count and leukogram were evident in BL-injected rats. BL notably disturbed thyroid profile as revealed by a significant increase of thyroid-stimulating hormone and thyroid peroxidase antibody. In contrast, both total and free forms of thyroid hormones (tri-iodothyronine and thyroxine), thyroglobulin, and thyroid peroxidase, were significantly decreased. Moreover, BL caused histopathological changes in the thyroid, thymus, and spleen tissues.CD4⁺ immuno-expression was reduced, but CD8⁺ immunolabelling was increased in both spleen and thymus. The daily dosing of VC to BL-exposed rats significantly corrected most of the deviations in immune parameters. It restored most of the thyroid architecture and function, revealing a significant protective effect of this vitamin. This experimental study demonstrates that BL abusing disrupts the immune system by different mechanisms and addresses BL, for the first time, as an autoimmune clinical hypothyroidism inducer drug. Additionally, VC is helpful in the management of BL abuse.

Pretransplant serum FT3 levels in recipients predict early non-relapse mortality after myeloablative allogeneic haematopoietic cell transplantation from matched sibling donors

OBJECTIVES

Although decreased thyroid function is negatively correlated with clinical outcomes in critically ill patients, its role in allogeneic haematopoietic cell transplantation (allo-HCT) has not been sufficiently described.

METHODS

The associations between pre-conditioning thyroid hormone concentrations and transplant-related complications in 474 adult patients with haematologic malignancies who underwent myeloablative allo-HCT were assessed.

RESULTS

A receiver-operating characteristic curve showed that the baseline serum-free triiodothyronine 3 (FT3) level had an excellent predictive value for non-relapse mortality (NRM) within 100 days in sibling HCT with an area under the curve of 0.73 [95% confidence interval (CI), 0.64-0.82]. With a cut-off value of 4.7 pmol/l, the sensitivity and specificity for early NRM were 68% and 73%, respectively. The cumulative incidences of early NRM within 100 days after sibling HCT were 14% (95% CI, 10-18%) in the low FT3 group and 6% (95% CI, 4-8%) in the high-FT3 group (p = 0.033). In multivariate analysis, a lower FT3 level was significantly associated with high early NRM (HR = 3.19, 95% CI, 1.13-9.03, p = 0.029). The difference was also significant at 3 years after HCT (24% vs. 14%, p = 0.046). Recipients with lower FT3 levels also had a trend towards a lower OS at 3 years after HCT (66% vs. 72%, p = 0.235), although the difference did not reach statistical significance.

CONCLUSION

A low FT3 level before conditioning may be a useful predictive biomarker for higher early NRM among patients undergoing myeloablative sibling transplantation.

A literature review on the adverse effects of hypothyroidism on kidney function

Thyroid produce two important hormone of thyroxine or tetraidothyronine (T4) and triidothyronine (T3), which are involved in whole aspect of metabolism. T4 and T3 play vital role in all biochemical function, growth and development in human body. The basic metabolic pathways in kidney and every organ in human controlled by these hormones. T4 and T3 are involved in kidney function in health and diseases condition therefore the pathophysiology of kidney can be directly influenced and regulated by thyroid hormones. Kidney growth, haemodynamic, blood circulation, tubular, electrolyte balance and glomerular filtration rate (GFR) are among such crucial process. Hypothyroidism which accompanied with reduced thyroid hormone production adversely affect the renal functions, development and eventually leading to reduced weight, kidney vascular disorders, electrolyte, tubular transport imbalances, lower filtration rate and other adverse consequences of hypothyroidism. On other hand kidney diseases can also disrupt the thyroid function metabolism resulting in the subsequent hypothyroidism. It is an interesting subject in how thyroid and kidney in health and diseases closely interacted. For the ideal clinical follow up of either of thyroid and renal diseases the two organs should be simultaneously examined for a proper patient management. Close correlation of thyroid and kidney clinical teams are essential to check the cross reactions and adverse interactions which might be produced between these two vital organs to avoid misdiagnosis either of thyroid or kidney abnormalities.

Thyroid status and kidney transplantation outcomes

INTRODUCTION

It is known that end-stage renal disease patients can display abnormal thyroid gland function, which may cause autoimmune hypothyroidism or subclinical alterations. The impact of thyroid function on graft outcomes is not completely clear among renal transplant patients. The aim of this study was to evaluate thyroid function among a cohort of 136 consecutive renal recipients in correlation with clinical parameters of graft function.

MATERIALS AND METHODS

We performed a cross-sectional study on 136 subjects including 84 males and 52 females of overall mean age of 49.71 ± 10.98 years who underwent renal transplantations between 2005 and 2009 and had a mean follow-up of 28.3 ± 15.7 months. All patients were treated with a calcineurin inhibitor, steroids, and mycophenolate mofetil. The exclusion criteria were age below 18 years, multiorgan transplantation, graft failure in the first 6 months, or presence of a thyroid neoplasm. We evaluated levels of serum FT3, FT4, and thyroid-stimulating hormone (TSH) in relation to the following parameters: body mass index (BMI), serum creatinine, estimated glomerular filtration rate estimated glomerular filtration rate (eGFR) by Modification of Diet in Renal Disease (MDRD) formula, proteinuria/24 hours, serum sodium, potassium, calcium, phosphorus, cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, and hemoglobin (Hb).

RESULTS

Only 6.4% of our transplant recipients were treated with levothyroxine sodium. The patients showed an average FT3 of 3.24 ± 0.5 mg/dL; average FT4 of 0.84 ± 0.1 mg/dL, and mean TSH of 1.29 ± 0.8 mg/dL. The study showed no relationship between thyroid hormones and age of the transplant, while there was a significant difference in FT3 levels between men and women. We also observed a significant correlation between FT3 and serum creatinine, eGFR, serum sodium, BMI, and Hb; whereas there was no correlation with other variables. The correlations between FT4 and TSH and all examined variables were not significant.

CONCLUSIONS

The interactions between the thyroid and the kidney have been incompletely studied among patients with renal transplants. Our data showed that the presence of low serum FT3 levels correlated with worse graft function, anemia, BMI, and serum sodium. Thus low FT3 levels could be predictive of graft function, especially in the 5 years posttransplantation.

Pretransplantation serum FT3 concentration in kidney recipients is useful to identify higher risk of graft failure

BACKGROUND

Free triiodothyronine (FT3) is a marker of comorbidity in end-stage renal disease and in many acute and chronic diseases. The objective of the present study was to investigate the effects of pretransplantation FT3 concentration on graft function.

MATERIALS AND METHODS

Between 2003 and 2008, the study enrolled 86 patients who underwent renal transplantation. Twenty-six patients were women, and 60 were men, with overall mean (SD) age of 38 (10) years. In all patients, serum FT3, free thyroxine, and thyroid-stimulating hormone concentrations were determined before transplantation. Demographic data and laboratory values were evaluated at 2 years posttransplantation.

RESULTS

The overall graft survival rate at 2 years was 82.1%. Pretransplantation serum FT3 concentration was inversely correlated with 2-year serum creatinine concentration (r=-0.29; P=.01) and proteinuria (r=-0.37; P<.00). Linear regression analysis demonstrated that serum FT3 (r2=0.63; 95% confidence interval, 0.52-0.74; P=.00) was a statistically significant risk factor for increased serum creatinine concentration. No correlation was observed for thyroid-stimulating hormone or free thyroxine and posttransplantation data.

CONCLUSION

Patients with end-stage renal disease with low pretransplantation serum FT3 concentration are at greater risk of subsequent graft failure. Measurement of pretransplantation serum FT3 concentration could be a clinically useful method of identifying patients at increased risk of graft failure.

Thyroid dysfunction and kidney disease

Thyroid hormones (TH) are essential for an adequate growth and development of the kidney. Conversely, the kidney is not only an organ for metabolism and elimination of TH, but also a target organ of some of the iodothyronines' actions. Thyroid dysfunction causes remarkable changes in glomerular and tubular functions and electrolyte and water homeostasis. Hypothyroidism is accompanied by a decrease in glomerular filtration, hyponatremia, and an alteration of the ability for water excretion. Excessive levels of TH generate an increase in glomerular filtration rate and renal plasma flow. Renal disease, in turn, leads to significant changes in thyroid function. The association of different types of glomerulopathies with both hyper- and hypofunction of the thyroid has been reported. Less frequently, tubulointerstitial disease has been associated with functional thyroid disorders. Nephrotic syndrome is accompanied by changes in the concentrations of TH due primarily to loss of protein in the urine. Acute kidney injury and chronic kidney disease are accompanied by notable effects on the hypothalamus-pituitary-thyroid axis. The secretion of pituitary thyrotropin (TSH) is impaired in uremia. Contrary to other non-thyroidal chronic disease, in uraemic patients it is not unusual to observe the sick euthyroid syndrome with low serum triodothyronine (T(3)) without elevation of reverse T(3) (rT(3)). Some authors have reported associations between thyroid cancer and kidney tumors and each of these organs can develop metastases into the other. Finally, data from recent research suggest that TH, especially T(3), can be considered as a marker for survival in patients with kidney disease.

Transport of thyroxine and 3,3',5-triiodothyronine in human umbilical vein endothelial cells

The prerequisite for the uptake of thyroid hormone (TH) in peripheral tissues is the exit of TH from the bloodstream. The first step in this process is transport across the endothelium. Little is known about this important step in TH physiology. Therefore, we aimed to characterize the TH transport processes across the endothelium using human umbilical vein endothelial cells as a model. Transport studies showed rapid uptake of 1 nm [(125)I]T(3) and [(125)I]T(4) in these cells. The apparent Michaelis constant value for [(125)I]T(3) uptake was about 1 microm, and the IC(50) for T(4) inhibition of T(3) uptake was about 3 microm. The aromatic amino acids phenylalanine, tyrosine, and tryptophan and the L-type amino acid transporter-specific ligand 2-aminobicyclo-(2, 2, 1)-heptane-2-carboxylic acid did not inhibit [(125)I]T(3) or [(125)I]T(4) uptake. Verapamil was capable of reversibly reducing transport of [(125)I]T(3) and [(125)I]T(4). Human umbilical vein endothelial cells incubated with the affinity label BrAcT(3) resulted in a labeling of multiple proteins, which are probably protein disulfide isomerase related. Extrapolating our findings to the endothelial lining of blood vessels suggests that T(3) and T(4) uptake is mediated by the same transport system. Because TH transport characteristics do not correspond to known TH transporters, further studies are required to identify the TH transporter protein(s) at the molecular level. Possible candidates may be widely expressed Na(+)-independent transporter proteins.

Effects of the hormones of the thyroid axis on the vitamin K-dependent plasma factors of blood coagulation (II, VII, IX, and X)

The hormonal regulation of haemostasis is a problem which has not received much attention. The data concerning the influence of hormones from the hypothalamic-pituitary-thyroid axis are scarce, contradictory and based mainly on clinical observations. The objective of the current research is to study the influence of the Thyrotropin releasing hormone (TRH), Thyroid stimulating hormone (TSH), Triiodothyronine (T3) and Thyroxin (T4) on the activity level of the vitamin K-dependent plasma factors of blood coagulation--factor II (F II), factor VII (F VII), factor IX (F IX) and factor X (F X). This study was carried out on 40 male Wistar rats. The necessary quantity of blood was obtained by cardiac puncture under ether narcosis. The indicators studied were activated partial thromboplastin time (aPTT), protothrombin time (PT), F II, F VII, F IX and F X, and were determined by means of Diagnostica Stago tests and with the help of an automatic coagulometer. The hormones studied were: TRH (0.06 mg/kg b.w.), TSH (1 MU/kg b.w.), T3 (0.08 mg/kg b.w.) T4 (0.08 mg/kg b.w.) prolonged aPTT (p<0.001) and PT (p<0.001). TRH and T3 significantly reduced the activity level of factors II, VII, IX and X; T4 only reduced the level of F II (p<0.05), and TSH did not induce significant changes in the haemocoagulation factors studied. The TRH, TSH, T3 and T4 hormones, although elements of one and the same axis, have an ambiguous effect on the vitamin K-dependent factors of blood coagulation. The results obtained show that the determined changes in the activity levels of the vitamin K-dependent plasma factors of blood coagulation are undoubtedly related to the hypocoagulation observed in the intrinsic and extrinsic pathways under the influence of the hormones of the thyroid axis.

Pretransplant serum FT3 levels in kidney graft recipients are useful for identifying patients with higher risk for graft failure

OBJECTIVE

End-stage renal disease (ESRD) is a condition associated with thyroid disturbances both in function and morphology. Recent studies demonstrated that serum free triiodothyronine 3 (FT3) levels are negatively correlated with serum markers of inflammation and endothelial activation in patients with ESRD. However, no previous research evaluated serum thyroid function parameters in relation to kidney graft outcome, as we aim to do so in this study.

DESIGN

Serum FT3, free thyroxine 4 (FT4) and TSH levels were measured before transplantation in 196 kidney graft recipients.

RESULTS

The graft survival rate at 5 years for all patients was 92.3%. Kidney graft recipients with normally functioning grafts showed serum pretransplant thyroid parameters similar to patients who experienced graft failure. Life-time analysis was performed after stratification of patients according to pretransplant serum FT3 levels < 3.1 pmol/l or > 3.1 pmol/l. A significantly different 5-year death-censored graft survival rate (93.9%vs. 76.5% for patients with normal or low FT3 levels, respectively; P < 0.01) and similar survival rate (death of patients with functioning grafts) (21.1%vs. 5.9%; P = 0.288) were observed. No similar feature was found for FT4 or TSH, suggesting that the effect is not related to hypothyroidism but rather dependent upon inappropriately low FT3 levels. Pretransplant serum FT3 levels were similar in patients who experienced early acute rejections as compared with nonrejector patients.

CONCLUSIONS

The results of this study demonstrate that among patients with ESRD undergoing kidney transplantation, those displaying lower pretransplant serum FT3 levels are at higher risk for subsequent graft failure. The demonstration of a predictive value of serum FT3 levels for graft survival suggests that measurement of pretransplant serum FT3 levels might represent a clinically useful parameter to identify patients with increased risk for graft failure.

A new mechanism involving ERK contributes to rosiglitazone inhibition of tumor necrosis factor-alpha and interferon-gamma inflammatory effects in human endothelial cells

OBJECTIVE

Microvascular endothelium is one of the main targets of the inflammatory response. On specific activation, endothelial cells recruit Th1-lymphocytes at the inflammatory site. We investigated the intracellular signaling mediating tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma inflammatory response in human microvascular endothelial cells (HMEC-1) and the interfering effects of the peroxisome-proliferator-activated-receptor (PPARgamma) agonist, rosiglitazone (RGZ).

METHODS AND RESULTS

TNFalpha and IFNgamma, mainly when combined, stimulate IFNgamma-inducible protein of 10 kDa (IP10) and fractalkine production evaluated by ELISA and TaqMan analyses. This effect is not only mediated by activation of the NFkB and Stat1 classic pathways, but also involves a rapid increase in phosphorylation and activation of extracellular signal-regulated kinases (ERK1/2) as measured by Western blot. RGZ interferes with TNFalpha and IFNgamma stimulation of IP10, fractalkine, and adhesion molecule through a novel rapid mechanism which involves the blocking of ERK activation.

CONCLUSIONS

Our findings shed new light on the mechanisms underlying the inflammatory response of microvascular endothelium and on the possible therapeutic use of RGZ in vasculopathies involving Th1-responses.