Relations between serum levels of TSH, TBG, T4, T3, rT3 and various histologically classified chronic liver diseases

Testosterone deficiency in male organ transplant recipients

Testosterone deficiency is known to affect men with increasing incidence throughout their lifespan. The clinical manifestations of testosterone deficiency, in turn, negatively impact men's quality of life and perception of overall health. The interaction of chronic systemic disease and androgen deficiency represent an area for potential intervention. Here, we explore the topic of testosterone deficiency amongst men with end-stage organ failure requiring transplantation in order to elucidate the underlying pathophysiology of androgen deficiency of chronic disease and discuss whether intervention, including testosterone replacement and organ transplantation, improve patients' outcomes and quality of life.

Thyroid Stimulating Hormone Levels Are Associated With Genetically Predicted Nonalcoholic Fatty Liver Disease

CONTEXT

Findings from observational studies indicate an association of thyroid hormone levels with the risk of nonalcoholic fatty liver disease (NAFLD); however, conflicting results remain and reverse causality may be a possibility.

OBJECTIVE

This study aimed to evaluate the associations between NAFLD and both plasma thyroxine (T4) and thyroid stimulating hormone (TSH) at the phenotypic and genetic levels.

METHODS

We included 14 797 participants, aged 20 to 74 years who had undergone abdominal ultrasonography during the Third National Health and Nutrition Examination Survey (NHANES III). Multivariable logistic regression analyses were used to examine the observational associations of TSH and T4 with NAFLD. Mediation analyses were performed to study whether the relationship between NAFLD and TSH levels was mediated via potential confounders. A bidirectional, two-sample Mendelian randomization (MR) analysis was used to determine the potential causal relationship.

RESULTS

Multivariable logistic regression model suggested a "dose-response" relationship between TSH (Q4 vs Q1: OR = 1.29; 95% CI, 1.10-1.52; Ptrend = 0.001) and NAFLD. BMI and ALT partially mediated the association between TSH and NAFLD, while the proportion of the mediation effects of BMI and ALT were 39.1% and 22.3%, respectively. In MR analyses, the inverse-variance weighted method was selected as primary method and suggested a putative causal effect of NAFLD on serum TSH levels (OR = 1.022; 95% CI, 1.002-1.043). The result was further validated in the sensitivity analyses.

CONCLUSION

Circulating TSH levels were associated with the risk of NAFLD. MR analysis suggested a putative causal effect of NAFLD on TSH levels.

Endocrine Diseases and the Liver: An Update

The endocrine system is a complex interconnected system of organs that control corporeal processes and function. Primary endocrine organs are involved in hormonal production and secretion but rely on a bevy of signals from the hypothalamic-pituitary axis and secondary endocrine organs, such as the liver. In turn, proper hepatic function is maintained through hormonal signaling. Thus, the endocrine system and liver are codependent, and diseases affecting either organs can lead to alterations in function within their counterparts. This article explores the hepato-endocrine relationship, including the effects on endocrine diseases on the liver.

Effects of liver transplantation on endocrine function: a systematic review

Patients with chronic liver disease (CLD) often experience secondary endocrine dysfunction. Therefore, because the liver plays a major role in endocrine function, liver transplantation (LT) may also be beneficial for the restoration of hormonal regulation. This systematic review collects and interprets the available literature on the effect of LT on endocrine and sexual function in adult patients. A systematic review was conducted by searching Pubmed (including Medline) and EMBASE for studies published from database inception until November 2015. We collected all relevant studies that discussed changes in hormonal and sexual function after LT. Studies were included if they assessed the effect of LT on sexual function or one of the following components of the hormone/endocrine axis: the hypothalamus-pituitary-gonadal axis, growth hormone (GH), insulin-like growth factor-1 (IGF-1) or thyroid function. The results are reported according to the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. Twenty-one studies with a total of 1274 patients were included. The results collected from the included studies suggested that LT improves the hormonal perturbation associated with CLD by restoring physiological levels of circulating GH, IGF-1, testosterone, estradiol, prolactin, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Thyroid function was not affected by LT, and sexual function was partially improved after LT. This systematic review suggests that LT is associated with an improvement in endocrine and sexual function in patients with CLD. This information should encourage clinicians who treat CLD patients to identify endocrine disturbances in this population, inform their patients of the effects of LT and assess post-transplantation improvements.

Thyrotropin isoforms: implications for thyrotropin analysis and clinical practice

Serum thyrotropin (TSH) is considered the single most sensitive and specific measure of thyroid function in the general population owing to its negative logarithmic association with free triiodothyronine and free thyroxine concentrations. It is therefore often the test of choice for screening, diagnosis, and monitoring of primary hypothyroidism. Serum TSH concentrations can be analyzed quantitatively using third-generation immunoassays, whereas its bioactivity can be measured by TSH activity assays in cell culture. Theoretically, if serum TSH concentrations are directly related to TSH activity, the two tests should yield comparable results. However, on occasion, the results are discordant, with serum concentrations being higher than TSH biological activity. This review focuses on the dissociation between the clinical state and serum TSH concentrations and addresses clinically important aspects of TSH analysis.

Liver abnormalities and endocrine diseases

The liver and its pleotropic functions play a fundamental role in regulating metabolism, and is also an inevitable target of multiple metabolic disorders. The numerous and constant relationships and feedback mechanisms between the liver and all endocrine organs is reflected by the fact that an alteration of one oftentimes results in the malfunction of the other. Hypo- and hyperthyroidism are frequently associated with hepatic alterations, and thyroid diseases must be excluded in transaminase elevation of unknown cause. Drugs such as propylthiouracil, used in the treatment of hyperthyroidism, may induce liver damage, and other drugs such as amiodarone, carbamazepine, and several chemotherapeutic agents can lead to both thyroid and liver abnormalities. Liver diseases such as hepatitis, hepatocellular carcinoma, and cirrhosis may cause altered levels of thyroid hormones, and alcoholic liver disease, both due to the noxious substance ethanol as well as to the hepatic damage it causes, may be responsible for altered thyroid function. Both excess and insufficiency of adrenal function may result in altered liver function, and adrenocortical dysfunction may be present in patients with cirrhosis, especially during episodes of decompensation. Again an important player which affects both the endocrine system and the liver, alcohol may be associated with pseudo-Cushing syndrome. Sex hormones, both intrinsic as well as extrinsically administered, have an important impact on liver function. While oestrogens are related to cholestatic liver damage, androgens are the culprit of adenomas and hepatocellular carcinoma, among others. Chronic liver disease, on the other hand, has profound repercussions on sex hormone metabolism, inducing feminization in men and infertility and amenorrhoea in women. Lastly, metabolic syndrome, the pandemia of the present and future centuries, links the spectrum of liver damage ranging from steatosis to cirrhosis, to the array of endocrine alterations that are features of the syndrome, including insulin resistance, central obesity, and hyperlipidaemia. Clinical practice must integrally evaluate the effects of the intricate and tight relationship between the liver and the endocrine system, in order to better address all manifestations, complications, and prevent deterioration of one or the other organ-system.

Thyroid disturbance related to chronic hepatitis C infection: role of CXCL10

Association between autoimmune thyroid diseases (AITD) and hepatitis C is controversial, but may occur or worsen during alpha-interferon treatment. The mechanism responsible for autoimmune diseases in infected patients has not been fully elucidated. This study aims to evaluate the frequency of AITD in chronic hepatitis C and the association of chemokine (CXC motif) ligand 10 (CXCL10) and AITD. One hundred and three patients with chronic hepatitis C and 96 controls were prospectively selected to clinical, hormonal, thyroid autoimmunity and ultrasound exams, besides thyroxine-binding globulin (TBG) and CXCL10 measurements and hepatic biopsies. The frequency of AITD among infected subjects was similar to controls. TT3 and TT4 distributions were right shifted, as was TBG, which correlated to both of them. Thyroid heterogeneity and hypoechogenicity were associated with AITD. Increased vascularization was more prevalent in chronic hepatitis C.CXCL10 was higher in infected patients (p=0.007) but was not related to thyroid dysfunction. Increase in CXCL10 levels were consistent with hepatic necroinflammatory activity (p=0.011). In summary, no association was found between chronic hepatitis C and AITD. Infected subjects had higher TT3 and TT4 which were correlated to TBG. Increased CXCL10 was not associated to thyroid dysfunction in HCV-infected population.

Inverse association between serum free thyroxine levels and hepatic steatosis: results from the Study of Health in Pomerania

BACKGROUND

Associations between thyroid function and hepatic steatosis defined by enzymatic and sonographic criteria are largely unknown in the general population. Thus, the aim of the present study was to investigate the association between thyroid function tests and sonographic as well as enzymatic criteria of liver status in a large population-based study, the Study of Health in Germany (SHIP).

METHODS

Data from 3661 SHIP participants without a self-reported history of thyroid or liver disease were analyzed. Hepatic steatosis was defined as the presence of a hyperechogenic ultrasound pattern of the liver and increased serum alanine transferase concentrations. Serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) concentrations were associated with hepatic steatosis using multinomial regression models adjusted for sex, age, physical activity, alcohol consumption, waist circumference, and food intake pattern.

RESULTS

We detected no consistent association of serum TSH and FT3 concentrations with hepatic steatosis. In contrast, serum FT4 concentrations were inversely associated with hepatic steatosis in men (odds ratio (OR)=0.04 [95% confidence interval (CI)=0.01; 0.17]) and women (OR=0.06 [95% CI=0.01; 0.42]).

CONCLUSIONS

Results from the present cross-sectional study suggest that low FT4 concentrations are associated with hepatic steatosis. Longitudinal and intervention studies are warranted to investigate whether hypothyroidism increases the risk of hepatic steatosis or vice versa.

Thyroid hormonal disturbances related to treatment of hepatitis C with interferon-alpha and ribavirin

OBJECTIVE

To characterize thyroid disturbances induced by interferon-alpha and ribavirin therapy in patients with chronic hepatitis C.

INTRODUCTION

Interferon-alpha is used to treat chronic hepatitis C infections. This compound commonly induces both autoimmune and non-autoimmune thyroiditis.

METHODS

We prospectively selected 26 patients with chronic hepatitis C infections. Clinical examinations, hormonal evaluations, and color-flow Doppler ultrasonography of the thyroid were performed before and during antiviral therapy.

RESULTS

Of the patients in our study, 54% had no thyroid disorders associated with the interferon-alpha therapy but showed reduced levels of total T3 along with a decrease in serum alanine aminotransferase. Total T4 levels were also reduced at 3 and 12 months, but free T4 and thyroid stimulating hormone (TSH) levels remained stable. A total of 19% of the subjects had autoimmune interferon-induced thyroiditis, which is characterized by an emerge of antithyroid antibodies or overt hypothyroidism. Additionally, 16% had non-autoimmune thyroiditis, which presents as destructive thyroiditis or subclinical hypothyroidism, and 11% remained in a state of euthyroidism despite the prior existence of antithyroidal antibodies. Thyrotoxicosis with destructive thyroiditis was diagnosed within three months of therapy, and ultrasonography of these patients revealed thyroid shrinkage and discordant change in the vascular patterns.

DISCUSSION

Decreases in the total T3 and total T4 levels may be related to improvements in the hepatocellular lesions or inflammatory changes similar to those associated with nonthyroidal illnesses. The immune mechanisms and direct effects of interferon-alpha can be associated with thyroiditis.

CONCLUSION

Interferon-alpha and ribavirin induce autoimmune and non-autoimmune thyroiditis and hormonal changes (such as decreased total T3 and total T4 levels), which occur despite stable free T4 and TSH levels. A thyroid hormonal evaluation, including the analysis of the free T4, TSH, and antithyroid antibody levels, should be mandatory before therapy, and an early re-evaluation within three months of treatment is necessary as an appropriate follow-up.

Feasibility Study of New Calibrators for Thyroid-Stimulating Hormone (TSH) Immunoprocedures Based on Remodeling of Recombinant TSH to Mimic Glycoforms Circulating in Patients with Thyroid Disorders

Background: Differences between the glycosylation patterns of a pituitary thyroid-stimulating hormone calibrator (pitTSH) and serum samples have been shown to be responsible for nonidentical epitope expression and for introducing discrepancies in TSH measurements. We studied the feasibility of developing new candidate reference materials by remodeling recombinant TSH (recTSH) to generate potential mimics of serum TSH.

Methods: Terminal sialylation and/or inner fucosylation of recTSH were remodeled by a combination of enzyme treatments followed (or not) by lentil lectin-Sepharose affinity chromatography. The resulting TSH preparations were screened for epitope similarity in 23 immunoassays mapping 3 antigenic clusters common to the pitTSH 2nd International Reference Preparation (IRP) and the recTSH 1st IRP and then challenged against a pool of 63 patients with increased serum TSH (>60 mIU/L).

Results: pitTSH was poorly correlated with serum TSH, with a mean (SD) slope of 2.124 (0.001), in contrast to recTSH [slope, 1.178 (0.056)]. Comparison of variably sialylated preparations with recTSH gave slopes of 0.860 (0.057) for desialylated TSH, 1.064 (0.057) for α2,3/6-oversialylated recTSH, and 0.953 (0.033) for α2,6-resialylated recTSH, indicating that TSH forms enriched in sialic acid closely resemble serum TSH. Further testing against serum TSH showed satisfactory agreement with both TSH preparations containing α2,6-sialic acid [slopes, 1.064 (0.057) and 0.953 (0.033)], particularly in the absence of nonfucosylated forms [0.985 (0.044)].

Conclusions: Glyco-engineered recTSH preparations enriched in sialic acid and inner fucose are promising candidates for future reference materials. These preparations may have advantages over existing preparations used for standardizing TSH measurements.

[Thyroid function tests in viral chronic hepatitis]

BACKGROUND

One hundred and twenty five patients with virus B or C chronic active hepatitis and postnecrotic cirrhosis and different degrees of liver dysfunction were studied.

AIM

1) To determine a thyroid hormonal profile; 2) to evaluate the prognostic value of these tests in relation to the progression of the disease and mortality; 3) compare these findings with Child-Pugh classification.

PATIENTS AND METHODS

The patients were divided in four groups: a) 31 with chronic active hepatitis; b) 41 with postnecrotic cirrhosis Child A; c) 35 with postnecrotic cirrhosis Child B and d) 18 with postnecrotic cirrhosis Child C. The protocol comprised serum measurements of albumin and bilirrubin, estimates of prothrombin time and clinical evaluation of ascites and encephalopathy, measurement of total serum triiodothyronine, thyroxine, thyroid-stimulating hormone, free thyroxine, reverse triiosothyronine, calculated rT3/T3 index (IrT3) and thyrotropin-releasing hormone test.

RESULTS

Total serum triiodothyromnine showed the most significant difference among the groups, gradually lower as the disease became more advanced (CAH: 149.2 +/- 42.3 ng/dL; PNC-A: 137.4 +/- 37.2 ng/dL; PNC-B: 88.0 +/- 28.4 ng/dL and PNC-C: 41.8 +/- 21.9 ng/dL). Low levels of T4 (4.5 +/- 2.0 micrograms/dL) and FT4 (0.7 +/- 0.4 ng/dL) and elevated levels of thyroid-stimulating hormone (7.2 +/- 11.5 microIU/mL), reverse triiosothyronine (60.8 +/- 52.1 ng/dL) and calculated rT3/T3 index (2.2 +/- 2.6) were more frequent in patients with postnecrotic cirrhosis Child C. Thyrotropin-releasing hormone test was normal in the majority of the patients.

CONCLUSION

The present study shows a positive relationship between the low serum levels of T3 and elevated serum levels of rT3 and IrT3/T3 with the degree of hepatic dysfunction according to the Child-Pugh classification.

Clinical associations between thyroid and liver diseases

The liver has an important role in thyroid hormone metabolism and the level of thyroid hormones is also important to normal hepatic function and bilirubin metabolism. Besides the associations between thyroid and liver diseases of an autoimmune nature, such as that between primary biliary cirrhosis and hypothyroidism, thyroid diseases are frequently associated with liver injuries or biochemical test abnormalities. For example, thyroid diseases may be associated with elevation of alanine aminotransferase and alkaline phosphatase, which is mainly of bone origin, in hyperthyroidism and aspartate aminotransferase in hypothyroidism. Liver diseases are also frequently associated with thyroid test abnormalities or dysfunctions, particularly elevation of thyroxine-binding globulin and thyroxine. Hepatitis C virus infection has been connected with thyroid abnormalities. In addition, antithyroid drug therapy may result in hepatitis, cholestasis or transient subclinical hepatotoxicity, whereas interferon (IFN) therapy in liver diseases may also induce thyroid dysfunctions. These thyroid-liver associations may cause diagnostic confusions. Neglect of these facts may result in over of under diagnosis of associated liver or thyroid diseases and thereby cause errors in patient care. It is suggested to measure free thyroxine (FT4) and thyroid-stimulating hormone (TSH) which are usually normal in euthyroid patients with liver disease, to rule out or rule in coexistent thyroid dysfunctions, and consider the possibility of thyroid dysfunctions in any patients with unexplained liver biochemical test abnormalities. It is also advisable to monitor patients with autoimmune liver disease or those receiving IFN therapy for the development of thyroid dysfunctions, and patients receiving antithyroid therapy for the development of hepatic injuries.

Thyroid function and serum IGF-1 in children before and after liver transplantation

We report results of serum thyroid hormone and IGF-1 concentrations in 20 children, 1.2 to 13.6 years old, with various degrees of chronic liver dysfunction (CLD), before and after successful orthotopic liver transplantation (OLT). Ten children presented with moderate chronic liver disease (CLD-M) with prothrombin time (PT) > 50% and serum albumin concentration > 3 g/dl; 7 children had severe chronic liver disease (CLD-S) with PT < 50% and serum albumin concentration < 3 g/dl; and 7 children who had received an OLT, who had normal liver function at the time of the study. Four of the latter group were also studied before OLT. Patients with CLD-M had normal mean +/- SD serum levels of total T3 (2.0 +/- 0.7 nmol/l), total T4 (125 +/- 25.9 nmol/l) and fT4 concentrations (16 +/- 2.8 pmol/l). In contrast, children with CLD-S showed a significant decrease in thyroid hormones together with normal basal TSH values (T3 0.8 +/- 0.0 nmol/l; T4 45.6 +/- 19.5 nmol/l; fT4 7.4 +/- 1.1 pmol/l; TSH 3.8 +/- 0.9 mU/l). Patients who received a successful OLT showed mean peripheral thyroid hormone concentrations significantly higher than CLD-S patients (T3 1.7 +/- 0.7 nmol/l, p < 0.005; T4 92.8 +/- 18.2 nmol/l, p < 0.001; fT4 14.5 +/- 3.1 pmol/l, p < 0.001). A significant correlation was found between thyroid hormone levels and PT or serum albumin. In the nine patients with CLD-M and CLD-S in whom serum IGF-1 concentration was measured, values found (mean +/- SD 0.08 +/- 0.05 U/ml) were below the 95% confidence limit of matched controls.

Elevated growth hormone levels in patients with non-alcoholic chronic liver disease

High serum concentrations of growth hormone (GH) were found in five patients with chronic liver diseases, including auto-immune chronic active hepatitis (two cases), Budd-Chiari syndrome, primary biliary cirrhosis and hepatitis B virus associated cirrhosis. Mean levels of GH were 27.8 units (normal up to 5). In three patients elevated prolactin levels were also found (mean 37.3 units for two females, normal up to 20), and 36 units in one male (normal up to 9). No other endocrine disorders were found. Although the association of raised GH levels in patients with alcoholic cirrhosis is well known, its occurrence in patients with non-alcoholic chronic liver disease is not fully established. We describe the effect of the disease course, and steroid treatment on GH levels in one patient with auto-immune chronic active hepatitis, and propose possible mechanisms for this elevation.

Evaluation of serum total thyroxine and triiodothyronine and their serum fractions in nonthyroidal illness secondary to congenital heart disease. Studies before and after surgery

Serum thyroid hormones, serum thyroxine-binding proteins and serum thyroid hormone fractions have been measured in children with congenital heart disease before and after open cardiac surgery. Twenty prepubertal patients, mean (+/- SD) age 3.6 +/- 3.7 yr, were studied before, immediately after, and 24 and 48 h after surgery. A control group of 6 normal prepubertal children was also studied in basal conditions. Serum TSH was normal in all samples collected. Significantly low mean levels of serum TBG (261 +/- 57 vs 456 +/- 71 nmol/L in normals), serum TBPA (2692 +/- 1119 vs 5999 +/- 2226 nmol/L), serum TBG-bound T4, serum TBPA-bound T4, serum TT3, serum TBG-bound T3 and free T3 were found before cardiac surgery in the patients. While serum binding proteins did not change after surgery, significant decrements in serum TT4, serum TBG-bound T4, serum TT3, serum TBG-bound T3, serum albumin-bound T3 and free T3 were observed after surgery. Free T4 and albumin-bound T4 remained normal. Our study shows that many features of nonthyroidal illness were present in our patients before surgery. In this context, the stress of surgery induced further alterations in several parameters of thyroid metabolism. It is concluded that the changes occurring in this model of chronic, as well as acute, nonthyroidal illness reflect adaptative changes, rather than altered thyroid function, as shown by normal serum free T4, serum albumin-bound T4 and serum TSH.

Increased serum cortisol binding in chronic active hepatitis

PURPOSE

A high serum cortisol concentration, apparently due to increased cortisol-binding globulin (CBG), was found in a patient (index case) with chronic active hepatitis (CAH). We therefore performed further studies to determine whether increased cortisol binding is generally associated with CAH.

PATIENTS AND METHODS

Serum samples were obtained from 15 hospitalized patients with long-term liver function test elevations but no evidence of cirrhosis, 15 normal subjects without a history of hepatitis, four healthy pregnant women, and 10 alcoholic patients with stigmata of cirrhosis. Serum cortisol binding was measured by an adaptation of a previously described charcoal uptake method. Thyroxine-binding globulin (TBG) and sex hormone-binding globulin were determined by radioimmunoassays.

RESULTS AND CONCLUSION

Charcoal uptake of 125I cortisol from sera of normal subjects and additional patients with CAH revealed that increased serum cortisol binding by a saturable site, presumably CBG, was associated with CAH. Cortisol binding was significantly correlated with immunoassayable TBG, suggesting that in CAH, similar mechanisms may be responsible for increasing the serum concentrations of CBG and TBG.

Serum thyroid hormone levels in patients with fulminant hepatitis: usefulness of rT3 and the rT3/T3 ratio as prognostic indices

To evaluate thyroid function in 19 patients with fulminant hepatitis (FH), we have measured total and free 3,5,3'-triiodothyronine (T3) and thyroxine (T4), 3,3',5'-triiodothyronine (reverse T3, rT3), thyroid-stimulating hormone (TSH) and thyroxin-binding globulin (TBG) in patients with FH, compared with those of 80 patients with other various liver diseases and of 10 healthy controls. Patients with FH showed the lowest values of serum T3 and the highest levels of rT3 among all patients with liver diseases studied. Furthermore, patients with FH showed a significant increase of rT3 in comparison with subacute hepatitis (SAH), "acute-on-chronic" (AOC) type of hepatic failure, ordinary and severe forms of acute hepatitis (AHo and AHs) and decompensated liver cirrhosis (LC-D). In addition, serum T3 and rT3 and the rT3/T3 ratio significantly correlated with prothrombin time (PT) and plasma methionine level. We also found that serum T3 and rT3 concentrations and the rT3/T3 ratio showed early and rapid normalization in cases of FH that survived, but they did not improve in patients with fatal outcome. These results suggest that serum T3, particularly rT3 concentrations and the rT3/T3 ratio may be useful indicators for assessing the severity and prognosis of patients with FH and can be considered to the sensitive indices for functioning hepatic microsomal reserve as well.

Antibody binding serum T3 in a patient with hepatocarcinoma

Thyroid hormone levels were studied in a euthyroid patient with hepatocellular carcinoma. The thyroid gland was normal at autopsy and both antithyroglobulin and antimicrosomal antibodies were undetectable in serum. Serum triiodothyronine (T3) values as measured by different RIA procedures, showed striking discrepancies suggesting the presence of an endogenous T3 binding antibody. The preincubation of the patient's serum with 125I-T3, followed by a precipitation with polyethyleneglycol showed a 74.8% of binding, confirming the presence of an endogenous factor interfering with T3 assays. Agarose electrophoresis of the patient's serum showed that 125I-T3 migrated mainly with the gammaglobulin fraction (60%). When immunoprecipitation tests with different antihuman antiimmunoglobulins were carried out, a positive binding for immunoglobulin G (11.9%), Fab (8.5%) and lambda chain (9.3%) was noted. Scatchard plot analysis showed a binding affinity of 0.77 X 10(9) liter/mol and a binding capacity of 1.02 nmol/liter. These data suggest that the abnormal serum T3 binding was caused by the presence of a T3 antibody which was shown to be an immunoglobulin G specific only for the lambda chain.

Elevated thyroxine levels due to increased thyroxine-binding globulin in acute hepatitis

Two patients are presented who had unexpected increases in serum thyroxine concentration due to acquired thyroxine-binding globulin excess associated with asymptomatic hepatitis. Serum hormone concentrations were also analyzed retrospectively in 10 outpatients with viral hepatitis. Acute hepatitis is associated with an increase in serum thyroxine and thyroxine-binding globulin concentrations and a corresponding decrease in the triiodothyronine resin uptake. In five patients, serum thyroxine concentration (mean +/- SD) was elevated at 21.08 +/- 5.86 micrograms/dl during illness, and decreased to 10.18 +/- 2.96 micrograms/dl during full recovery (p less than 0.05); serum thyroxine-binding globulin concentration was elevated at 2.14 +/- 0.36 mg/dl during illness, and decreased to 1.18 +/- 0.16 mg/dl during recovery (p less than 0.01). Interpretation of thyroid function test results can be difficult in patients with hepatitis. When serum thyroxine is elevated, careful attention to a decrease in the triiodothyronine resin uptake is essential to avoid the incorrect diagnosis of hyperthyroidism. Occasionally, this change in the triiodothyronine resin uptake may be the first evidence of occult hepatic inflammation.

Thyroxine binding globulin and thyroid function tests in patients with hepatocellular carcinoma

To determine the prevalence of elevated serum concentrations of thyroxine binding globulin (TBG) in patients with hepatocellular carcinoma (HCC) and the influence of the associated cirrhosis, TBG was measured in 39 patients with HCC, 22 with and 17 without cirrhosis, in 20 patients with cryptogenic macronodular cirrhosis but without HCC, and in 40 matched controls. The mean serum TBG concentration in the patients was 34.5 +/- 17.7 microgram per ml, compared to 21.4 +/- 6.8 microgram pr ml in controls and 20.5 +/- 6.3 microgram per ml in cirrhosis without HCC (p less than 0.01). The presence or absence of cirrhosis in the HCC patients did not significantly influence the frequency with which elevated TBG levels were found; levels were normal in every subject with cirrhosis and no HCC. The mean thyroxine (T4): TBG ratio was 5.58 +/- 1.78 in controls and was reduced in HCC patients with both elevated (3.33 +/- 0.80, p less than 0.001) and normal TBG values (4.39 +/- 1.90, p less than 0.05), and in cirrhotics without HCC (4.29 +/- 1.01, p less than 0.01). T4 and TBG concentrations correlated significantly in controls, in HCC patients with elevated TBG, and in the cirrhotics without HCC. It is concluded that in patients with HCC (i) TBG levels may be elevated both in the presence or absence of cirrhosis; (ii) there is reduced binding of T4 TBG, and (iii) a low T4:TBG ratio excludes the diagnosis of hyperthyroidism in the presence of high T4 levels. TBG levels are normal in patients with cryptogenic macronodular cirrhosis without HCC.