Subacute Thyroiditis After Sars-COV-2 Infection

CONTEXT

Subacute thyroiditis (SAT) is a thyroid disease of viral or postviral origin. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that began in Wuhan, China, has spread rapidly worldwide and Italy has been severely affected by this outbreak.

OBJECTIVES

The objective of this work is to report the first case of SAT related to SARS-CoV-2 infection.

METHODS

We describe the clinical, laboratory, and imaging features of an 18-year-old woman who came to our attention for fever, neck pain radiated to the jaw, and palpitations occurring 15 days after a SARS-CoV-2-positive oropharyngeal swab. Coronavirus disease 2019 (COVID-19) had been mild and the patient had completely recovered in a few days.

RESULTS

At physical examination the patient presented with a slightly increased heart rate and a painful and enlarged thyroid on palpation. At laboratory exams free thyroxine and free triiodothyronine were high, thyrotropin undetectable, and inflammatory markers and white blood cell count elevated. Bilateral and diffuse hypoechoic areas were detected at neck ultrasound. One month earlier, thyroid function and imaging both were normal. We diagnosed SAT and the patient started prednisone. Neck pain and fever recovered within 2 days and the remaining symptoms within 1 week. Thyroid function and inflammatory markers normalized in 40 days.

CONCLUSIONS

We report the first case of SAT after a SARS-CoV-2 infection. We alert clinicians to additional and unreported clinical manifestations associated with COVID-19.

The Detection of Serum IgMs to Thyroglobulin in Subacute Thyroiditis Suggests a Protective Role of IgMs in Thyroid Autoimmunity

CONTEXT

The role of serum immunoglobulin (Ig)Ms in autoimmune thyroid diseases is uncertain.

OBJECTIVE

We looked for IgMs to thyroglobulin (Tg) in patients with subacute thyroiditis (SAT), which is characterized by high serum Tg levels, the possible de novo appearance of IgGs to Tg (TgAb-IgGs), and no autoimmune sequelae.

MAIN OUTCOME MEASURES

TgAb-IgMs and TgAb-IgGs were detected by binding to Tg using the enzyme-linked immunosorbent assay (ELISA). The upper reference limit of TgAb-IgMs and TgAb-IgGs was established in 40 normal subjects. We looked for TgAb-IgMs in 16 patients with SAT, 11 with Hashimoto's thyroiditis (HT), and 8 with Graves' disease (GD) who were all positive for TgAb-IgGs. IgM binding to bovine serum albumin (BSA), keyhole limpet hemocyanin (KLH), and glucagon in ELISA was measured. Inhibition of TgAb-IgMs binding to coated Tg was evaluated by preincubating serum samples or IgG-depleted samples with soluble Tg.

RESULTS

TgAb-IgMs were positive in 10/16 patients with SAT, 2/11 with HT, and 1/8 with GD. TgAb-IgMs were higher in SAT (0.95; 0.42-1.13) (median; 25th-75th percentiles) than in HT (0.47; 0.45-0.51) and GD patients (0.35; 0.33-0.40) (P < .005 for both). IgM binding of SAT sera to BSA, KLH, and glucagon was significantly lower than Tg. Preincubation with soluble Tg reduced the binding of IgMs to coated Tg by 18.2% for serum samples and by 35.0% and 42.1% for 2 IgG-depleted samples. TgAb-IgM levels were inversely, although nonsignificantly, correlated with Tg concentrations.

CONCLUSIONS

Tg leak associated with thyroid injury induces the production of specific TgAb-IgMs, which, in turn, increases the clearance of Tg and might prevent the establishment of a persistent thyroid autoimmune response.

Establishing a diagnostic scale of subacute thyroiditis without radioisotope scanning

BACKGROUND

Radioisotope scanning is important to diagnose subacute thyroiditis (SAT), but it's not always available. So we aim to establish a diagnostic scale for SAT without radioisotope scanning.

METHODS

The suspected SAT patients hospitalized in Yuebei people's Hospital from January 2012 to December 2016 were selected and divided into study group and control group according to whether they were diagnosed as SAT. The clinical indexes of two groups were collected and the diagnostic scale of SAT was established by using binary logistic regression analysis. The effectiveness of the scale was evaluated by ROC curve.

RESULTS

Of 309 patients, 58.25% of patients were confirmed with SAT and the remaining 41.75% of patients were not diagnosed with SAT. After univariate analysis, variables which were considered statistically different(P < 0. 05) between the two groups were selected as independent variables and the diagnosis of SAT was taken as dependent variable in the binary logistic regression model. The logistic regression model consisted of 4 variables, each was thyroid tenderness, firm on palpation, increased ESR and elevated thyroid hormone level. The P value of Omnibus tests was≤0. 001 and the Nagelkerke R Square was 0. 915. The diagnostic scoring scale was established with these four variables according to their regression coefficient. The area under the ROC curve for this diagnostic scale was 0. 991(95% confidence interval, 0. 982-0.999). The highest Youden index was 0. 912, the corresponding cut-off point was 7. Internally validation shows a sensitivity of 92. 78% and a specificity of 98.45% of our scale.

CONCLUSIONS

We established and validated a diagnostic scale for SAT without the need for radioisotope scanning for the first time. It has good application in institutions that do not have radioisotope machines or among pregnant and lactating women.

Eosinophil/Monocyte Ratio Combined With Serum Thyroid Hormone for Distinguishing Graves' Disease and Subacute Thyroiditis

Background: Thyrotoxicosis is commonly classified into several entities according to different etiologies. Identifying the causes of thyroid dysfunction is critical for the subsequent selection of treatment. The free triiodothyronine to free thyroxine ratio (fT₃/fT₄) is widely used but is still a controversial diagnostic measurement. Methods: A total of 290 patients including 141 healthy control subjects, 86 patients with untreated Graves' disease (GD,) and 63 patients with subacute thyroiditis (SAT) were enrolled in the study. The main aim was to evaluate the diagnostic value of different indexes from serum testing including fT₃, fT₄, eosinophils (Eo) and monocytes (Mo). The diagnostic performance of multiple indexes was evaluated separately using receiver operating characteristic curve analysis. Results: Sensitivities and specificities of fT₄/fT₃, Mo/Eo ratios and Mo/Eo ratio + fT₄/fT₃ for diagnosing GD were 80.23 and 88.89, 82.56 and 60.32, and 74.4 and 87.3 with cut-off values of ≤ 2.841, ≤ 8.813 and >0.644, respectively. An equation of combined indicators including Mo, Eo, fT₃, and fT₄ data was developed to calculate a probability value and among all indexes studied the indicator combination formula gave the best diagnostic value, reaching sensitivity and specificity of 89.53 and 90.48%, respectively, with an optimum cut-off value at 0.561 for GD diagnosis. Conclusion: Compared to regular indexes (fT_4/fT₃ and Mo/Eo), a newly developed indicator combination formula provided a higher prediction probability and may serve as a simple, cost-effective tool for differentiating GD from SAT patients, especially in undeveloped regions of China.

Time-Lag Between Symptom Onset and Diagnosis of Subacute Thyroiditis - How to Avoid the Delay of Diagnosis and Unnecessary Overuse of Antibiotics

Clinical symptoms of subacute thyroiditis (SAT) may be misleading and the proper diagnosis is significantly delayed, and many unnecessary therapeutic methods are used, including application of antibiotics. The purpose of the study is to analyze the reasons and frequency of delayed SAT diagnosis and unnecessary antibiotic treatment and to propose a simple algorithm to facilitate the diagnosis and prevent antibiotic abuse. Sixty-four SAT patients were divided into groups depending on the period of time from the first symptoms of SAT to diagnosis and on the unnecessary use of antibiotics. Data from medical history and laboratory test results were analyzed for individual groups to determine the reasons for delayed diagnosis and incorrect treatment. In 73% of patients, the diagnosis was delayed from over two weeks up to six months. Among 62 patients who provided data on antibiotic use, 29 (46.77%) were treated with one or more antibiotics due to SAT symptoms. Fever, preceding infection, increased C-reactive protein (CRP), and WBC were characteristic for the antibiotic treated group. Fever, preceding infection, increased CRP and WBC are typical for both SAT and infection and are the main symptoms leading to misdiagnosis and unnecessary antibiotic treatment in SAT. Thus, in all patients with neck pain or other SAT-like symptoms, thorough clinical examination of the neck is mandatory. When firm and/or tender thyroid nodule/goitre is present and erythrocyte sedimentation rate /CRP is increased, patient should be promptly referred to an endocrinologist, and antibiotics are not recommended.

Neutrophil-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, and platelet-tolymphocyte ratio in different etiological causes of thyrotoxicosis

Background/aim

The most common causes of thyrotoxicosis include Graves’ disease (GD), toxic multinodular goiter (TMNG), toxic adenoma (TA), and subacute granulomatous thyroiditis (SAT). In our study, we aimed to see whether neutrophil‐to‐lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet‐to‐lymphocyte ratio (PLR), and mean platelet volume (MPV) may be helpful in the differential diagnosis of these diseases.

Materials and methods

We retrospectively analyzed the hospital records of the Endocrinology Clinic of our hospital between 2016 and 2019. We included data from 66 GD, 37 TA, and 35 SAT patients. We compared the data with those of 35 healthy subjects as controls.

Results

NLR, MLR, and PLR were found to be higher in the SAT group when compared to other groups. The post hoc analysis of comparison of NLR, MLR, and PLR in each group showed that NLR and PLR were significantly different in the SAT group when compared to the GD, TA, and controls groups (P < 0.001, P = 0.003, and P < 0.001 for NLR respectively and P < 0.001 for PLR in all groups). MPV levels were different between groups (P = 0.007). However, the intergroup analysis (Tukey’s test) failed to show a statistically significant difference for any of the groups. In patients with SAT, PLR and NLR were significantly higher than in the GD, TA, and control groups. MLR was also higher in SAT when compared to other groups, but the difference was not statistically significant.

Conclusion

High PLR and NLR may be helpful to differentiate SAT from GD and TA, the other common causes of thyrotoxicosis.

TNF-alpha is upregulated in subacute thyroiditis and stimulates expression of miR-155-5p in thyroid follicle cells

Tumor necrosis factor alpha (TNF-α) regulates the expression of proinflammatory cytokines and apoptosis in thyroids. miR-155-5p is upregulated in circulating microvesicles in patients with autoimmune thyroiditis. However, the function and molecular mechanisms of TNF-α and miR-155-5p in the initiation and progression of subacute thyroiditis are largely unknown. Herein, we determined serum TNF-α levels in subacute thyroiditis patients and normal healthy controls by ELISA assay. Proliferation and apoptosis of rat thyroid follicle FRTL-5 cells were determined by MTT, TUNEL, and annexin V staining assays. Protein levels and phosphorylation status were assessed by immunoblotting. miR-155-5p expression was determined by the real-time quantitative PCR. Serum TNF-α was significantly upregulated in patients with subacute thyroiditis compared to that in normal healthy controls. In rat thyroid follicle FRTL-5 cells, TNF-α treatment led to a reduction of cell proliferation and an induction of apoptosis. It also increased IL-6 expression and phosphorylation of JAK2 and STAT3. Importantly, we demonstrated that serum miR-155-5p was upregulated in subacute thyroiditis patients and TNF-α stimulated the expression of miR-155-5p in FRTL-5 cells. We found that miR-155-5p inhibited the proliferation and induced apoptosis of FRTL-5 cells and increased the expression of IL-6 in FRTL-5 cells. Our results demonstrated that serum TNF-α and miR-155-5p were upregulated in patients with subacute thyroiditis, and TNF-α inhibited proliferation and induced apoptosis of rat thyroid follicle FRTL-5 cells via modulating the IL-6-JAK2/STAT3 pathway and miR-155-5p signaling. Our findings suggest that miR-155-5p might be a novel biomarker of subacute thyroiditis.

Comparison of thyroglobulin and thyroid peroxidase antibodies measured by five different kits in autoimmune thyroid diseases

It is generally believed that the detection of thyroid peroxidase antibodies (TPOAb) is superior to that of thyroglobulin antibodies (TgAb) for the diagnosis of Hashimoto's thyroiditis. However, limited data are available on the comparison of TgAb and TPOAb prevalence as a diagnostic measurement for Hashimoto's thyroiditis using sensitive immunoassays. We herein used five different current immunoassay kits (A-E) to compare the prevalence of TgAb and TPOAb in Hashimoto's thyroiditis (n = 70), Graves' disease (n = 70), painless thyroiditis (n = 50), and healthy control subjects (n = 100). In patients with Hashimoto's thyroiditis, positive TgAb was significantly more frequent than positive TPOAb in kits A-D (mean ± SD of the four kits: 98.6 ± 1.7 vs 81.4 ± 2.0%). In patients with Graves' disease, TgAb prevalence was almost equivalent to that of TPOAb in five kits. Patients with painless thyroiditis exhibited positive TgAb significantly more frequently than positive TPOAb in kits A-D (73.5 ± 4.1 vs 33.0 ± 3.4%). The prevalence of TgAb alone was significantly higher than that of TPOAb alone in both Hashimoto's thyroiditis and painless thyroiditis in kits A-D. In kit E, TgAb and TPOAb prevalence did not differ significantly for any disease, and TgAb distribution was different from other kits. In conclusion, the prevalence of TgAb was higher than that of TPOAb in patients with Hashimoto's thyroiditis and painless thyroiditis using commercially available kits. We suggest that TgAb immunoassay is the first choice of screening test for thyroid autoimmune abnormalities in Japan.

Subacute thyroiditis masquerading giant cell arteritis

Subacute thyroiditis (SAT) and giant cell arteritis (GCA) are rare diseases. Occurrence of both of these diseases is incidental or one disease presenting with symptoms of other disease is very rare. Our patient presented with symptoms of giant cell arteritis and was diagnosed with subacute thyroiditis.

Thyroglobulin autoantibodies of patients with subacute thyroiditis are restricted to a major B cell epitope

BACKGROUND

Thyroglobulin autoantibodies (TgAb) can develop in patients with subacute thyroiditis (SAT).

AIM

Comparison of the epitope pattern of TgAb of patients with SAT, Hashimoto's thyroiditis (HT) [autoimmune thyroid disease (AITD)] and non-toxic multinodular goiter (NTMG) (non-AITD).

SUBJECTS AND METHODS

Serum TgAb from 10 patients with SAT, 45 with HT, and 19 with NTMG were evaluated. Serum TgAb binding to Tg was inhibited by 4 recombinant human TgAb-Fab, recognizing Tg epitope regions A, B, C, and D. The ability of single TgAb-Fab to inhibit the binding of serum TgAb to Tg was evaluated in enzymelinked immunosorbent assay.

RESULTS

Levels of inhibition were different for all TgAb-Fab in the 3 groups of patients. Inhibition by region A TgAb-Fab in SAT [50.5 (30.3-62.5)%] (median and 25th to 75th percentiles) was similar to HT [49.0 (38.0-69.5)%] and significantly higher than in NTMG [25.0 (14.0-37.0)%]; by region B TgAb-Fab in SAT [0.0 (0.0-12.5)%] was significantly lower than in HT [28.0 (9.5-48.0)%] and similar to NTMG [9.0 (4.8-20.5)%]; by region C TgAb-Fab in SAT [9.5 (0.0-25.8)%] were similar to HT [23.0 (9.5-41)%] and NTMG [6.5 (1.7-21.5)%]; and by region D TgAb-Fab in SAT [0.0 (0.0-8.0)%] were lower than in HT [12.0 (1.0-28.5)%] and similar to NTMG [1.0 (0.0-5.0)%].

CONCLUSIONS

The epitope pattern of TgAb of SAT is restricted to the A region that is immunodominant in AITD and non-AITD. In the majority of patients with SAT, the autoimmune phenomena represent a non-specific and transient response to the release of thyroid antigens, rather than the expression of thyroid autoimmunity.

Subacute thyroiditis in a patient with juvenile idiopathic arthritis undergoing etanercept treatment: a case report and review of the literature

We report on a 24-year-old woman with juvenile idiopathic arthritis (JIA) who developed subacute thyroiditis (SAT) while being treated with etanercept. She had suffered from JIA for 12 years, and her arthritis proved refractory to treatment with ibuprofen, prednisolone, and methotrexate. For the past 5 years, the patient had been treated successfully with etanercept at 25 mg/week. The patient more recently complained of high fever and lassitude, and presented with anterior neck swelling and tenderness. Palpation of the thyroid gland revealed it to be warm, erythematous, tender, and diffusely swollen. Laboratory tests revealed an increased erythrocyte sedimentation rate and C-reactive protein level. Thyroid function tests revealed decreased levels of thyrotropin-stimulating hormone, increased levels of free triiodothyronine, free thyroxine, and thyroglobulin, and an absence of thyroid autoantibodies. Sonography showed a diffusely reduced predominantly hypoechoic thyroid gland. Unenhanced computed tomography of the neck showed a homogeneously and mildly reduced thyroid gland. Serum titers of several viruses were not significant and so were considered unlikely to be the pathogens. On the basis of these presented findings, we diagnosed SAT, and etanercept therapy was withdrawn. The patient was treated with antibiotics and an increased prednisolone dose was initiated. She became symptom free and showed improved laboratory test results within 2 weeks, and was euthyroid by 3 months. Three months later, the patient developed hypothyroidism, although 6 months further on, the patient was asymptomatic on prednisolone, methotrexate, and levothyroxine therapy. In conclusion, whether SAT is a specific adverse event in this case in response to etanercept remains unclear. Nevertheless, the possibility of SAT should be considered in such patients on etanercept treatment.

The role of sonoelastography in acute, subacute and chronic thyroiditis: a novel application of the method

OBJECTIVE

Reports on sonoelastography, which provide an objective estimation of tissue elasticity, are scarce in terms of thyroiditis. The aim of this study was to prospectively assess the applicability of sonoelastography in different types of thyroiditis.

DESIGN

The study assessed and compared the thyroid tissue stiffness in patients with acute thyroiditis (AT), subacute thyroiditis (SAT), and chronic autoimmune thyroiditis (CAT) with healthy control subjects (CS), followed up for 10 weeks.

METHODS

The study group consisted of two patients with AT, 18 patients with SAT, 18 patients with CAT, and 40 CS matched for age and gender. Sonoelastography was performed at baseline, at a 4-week follow-up during treatment, and at 10 weeks following diagnosis and treatment initiation.

RESULTS

Thyroid tissue stiffness was higher in SAT at baseline (214.26 ± 32.5 kPa) in comparison with values recorded at a 4-week follow-up (45.92 ± 17.4 kPa) and at 10 weeks following diagnosis and treatment initiation (21.65 ± 5.3 kPa, P < 0.0001). Baseline thyroid stiffness in SAT was higher than that found in CAT (36.15 ± 18.7 kPa, P < 0.0001) and CS (16.18 ± 5.4 kPa, P < 0.0001). In the remission of SAT, thyroid stiffness was lower than that found in CAT (P = 0.006), while it was higher than that in CS (P = 0.0008). No difference was observed between thyroid stiffness in SAT at 4-week follow-up and in CAT. Patients with CAT presented higher thyroid stiffness than CS (P < 0.0001), which was not influenced by L-thyroxine treatment. Thyroid stiffness in patients with AT was 216.6 and 241.9 kPa at baseline; after treatment, it decreased to 17.93 and 85.348 kPa respectively.

CONCLUSIONS

Sonoelastography may assist in the diagnosis and treatment monitoring of AT, SAT and CAT, as well as in the differentiation of the various types of thyroiditis.

A case report of subacute thyroiditis during pregnancy: difficulties in differential diagnosis and changes in cytokine levels

INTRODUCTION

Thyroid dysfunction during pregnancy may result in both maternal and neonatal complications. Subacute thyroiditis (SAT) is an extremely rare cause of both hyper- and hypothyroidism in pregnant women.

CASE DESCRIPTION

A case of first trimester SAT is presented. Diagnosis of SAT was based on fine-needle aspiration biopsy. The disease resolved spontaneously without need for prednisone administration but a hypothyroid phase treated with T4 throughout pregnancy occurred. The pregnancy resulted in a healthy full term infant. We measured various cytokine levels in an attempt to follow their course during SAT as well as throughout the remaining period of pregnancy. Serum thyreoglobulin (Tg) levels correlated best with thyroid function tests (TFTs) and the course of SAT.

CONCLUSIONS

The diagnosis of SAT at a pregnancy setting may be intriguing. The measurement of circulating cytokines is not helpful in the differential diagnosis or monitoring of the disease.

A case of Takayasu's arteritis associated with human leukocyte antigen A24 and B52 following resolution of ulcerative colitis and subacute thyroiditis

A 46-year-old female with a past history of ulcerative colitis (UC) was diagnosed with subacute thyroiditis (SAT), which improved with prednisolone (PSL) treatment (60 mg/day). The dose of PSL was gradually decreased, however upper back and neck pain and chest discomfort developed. The patient was diagnosed with Takayasu's arteritis (TA) based on wall thickening and luminal narrowing of the left common carotid artery and the left subclavian artery. The result of human leukocyte antigen typing analysis was A24 and B52 positive. These findings suggested that common genetic factors may be important for the etiology of TA, UC and SAT. This is the first report of TA that developed following UC and SAT.

A novel bioreporter assay for thyrotropin receptor antibodies using a chimeric thyrotropin receptor (mc4) is more useful in differentiation of Graves' disease from painless thyroiditis than conventional thyrotropin-stimulating antibody assay using porcine thyroid cells

BACKGROUND

Graves' disease (GD) is caused by thyrotropin (TSH) receptor antibodies (TSHRAbs) that bind to TSHR and activate thyrocytes. The measurement of TSHRAbs therefore has been used to assist in the diagnosis and management of GD.

METHODS

In this study, we evaluated the clinical significance of a newly developed bioreporter assay for the detection of TSHRAbs (Thyretain). The Thyretain bioreporter assay utilizes a chimeric receptor (Mc4), in which residues 262-335 of TSHR are replaced with a rat lutropin-choriogonadtropin receptor segment. This bioreporter is designed to specifically detect stimulating TSHRAbs (Mc4-TSHRAbs).

RESULTS

The Mc4-TSHRAb level of sera obtained from 110 normal healthy controls, 103, 99, and 50 patients with untreated GD, painless Hashimoto's thyroiditis (PT), and subacute thyroiditis (SAT) were 27.3% +/- 11.3%, 327.8% +/- 105.9%, 48.9% +/- 48.5%, and 24.9% +/- 13.4%, respectively. Compared with the Mc4-TSHRAb levels of patients with PT and SAT, and normal healthy controls, the Mc4-TSHRAb levels of untreated GD patients were significantly higher (p < 0.01). The sensitivity and specificity of the Thyretain bioreporter assay for GD and PT were 95.1% and 96.0%, respectively, at the optimal cut-off value of 128%. Measurement of TSHRAbs with a bioassay that uses porcine thyroid cells (TSH-stimulating antibody [TSAb]) showed a positive correlation (r = 0.472, p < 0.001) with the Thyretain assay for untreated GD, and strong positive correlation (r = 0.821, p < 0.001) for the entire untreated GD, PT, and SAT population. The positive rate of Mc4-TSHRAbs for GD was significantly higher than that of TSAb (95.1% vs. 89.3%, p < 0.05) and the negative rate of PT by Mc4-TSHRAbs was also significantly higher than that of TSAb (96.0% vs. 86.9%, p < 0.01). As a result, Mc4-TSHRAbs showed statistically better (p < 0.01) diagnostic accuracy in differentiating GD from PT than TSAb.

CONCLUSIONS

These data suggest that the Thyretain bioreporter assay with a chimeric TSHR (Mc4) is more useful in the differential diagnosis of GD from PT than the bioassay with wild-type TSHR on porcine thyroid cells.

Clinical characteristics of 852 patients with subacute thyroiditis before treatment

OBJECTIVE

Subacute thyroiditis (SAT) is a transient inflammatory disease of the thyroid. We evaluated the clinical characteristics based on laboratory and imaging studies in patients with SAT before treatment.

PATIENTS

We reviewed the medical records of 852 patients (107 men and 745 women) with SAT who visited our thyroid clinic at Kuma Hospital from 1996 through 2004.

RESULTS

SAT developed most often in female patients aged 40 to 50 years, with significant seasonal clusters during summer to early autumn. While the rates of any virus infections and diseases did not differ from those in the general population, recurrent episodes of SAT at intervals of 13.6+/-5.6 years accounted for 1.6% of all cases. At the onset of SAT, 28.2% of patients had temperatures greater than 38 degrees C and typical symptoms associated with thyrotoxicosis developed in more than 60% of patients. Before treatment, most of the abnormal laboratory findings associated with thyrotoxicosis, inflammation, and liver dysfunction reached peak levels within 1 week after onset. Ultrasound examination showed that half of the patients with unilateral thyroid pain presented with bilateral hypoechogenic area in the thyroid and the rate of bilateral hypoechogenic area tended to increase 2 months after onset.

CONCLUSION

Laboratory studies of thyroid dysfunction and inflammation related to SAT presented peak levels within 1 week after onset.

"Thyrotoxic psychosis" associated with subacute thyroiditis

Severe psychiatric derangements are a rare manifestation of Graves disease or toxic goiter. An 18-year-old male college student was hospitalized with depression and psychotic behavior. He was found to have thyrotoxicosis due to subacute thyroiditis, as evidenced by a reduced radioactive iodine uptake, elevated thyroglobulin level, and spontaneous remission into a hypothyroid phase. His behavioral abnormalities resolved with progressive normalization of thyroid function. To our knowledge, this is the first reported case of the self-limited condition of subacute thyroiditis causing 'thyrotoxic psychosis' and serves to remind clinicians of this association when treating patients in clinical practice.

Clinical evaluation of 3rd generation assay for thyrotropin receptor antibodies: the M22-biotin-based ELISA initiated by Smith

Recently a new procedure for measuring serum TSH receptor (TSHR) autoantibody (TRAb) was reported by Smith et al. in which the autoantibodies inhibit binding of a human monoclonal thyroid stimulating antibody M22 (labeled with biotin) to TSHR-coated ELISA plate wells (pTRAb(3rd) assay). The aim of this study was to compare the performance of pTRAb(3rd) assay with pTRAb(2nd) assay based on inhibition of TSH-biotin binding to TSHR-coated ELISA plate wells. In addition, we evaluated the applicability of TRAb3rd assay to discriminate between untreated Graves' disease (GD) and painless thyroiditis (PT). Analysis of sera from 230 healthy controls indicated that only 1 (0.43%) gave inhibition of M22-binding values of greater than 15% (32.8% inhibition). To define the clinical cut-off point for a positive serum with autoantibodies to the TSHR, we performed receiver operating characteristic curve of the data from 244 untreated GD and three different control groups for pTRAb(3rd) assay. With a sensitivity of 99.6% at a cut-off of 14.5%, 22.0% and 22.0% inhibition of M22 binding, the specificity of healthy controls without PT, with PT and with PT excluding postpartum PT and PT during remission of GD was 99.6%, 96.6% and 97.5%, respectively. The pTRAb(3rd) assay was closely correlated to pTRAb(2nd) assay in the 244 untreated Graves' sera (r = 0.911). The pTRAb(3rd) assay detected 243 of 244 (99.6%) untreated GD, whereas 9.2% of PT and 6.7% of the subacute thyroiditis (SAT) were detectable. In contrast, pTRAb (2nd) assay detected 242 of 244 (99.2%) Graves' same sera, while 16.8 % from PT's same sera and 13.3% from SAT were detectable. In conclusion, pTRAb(3rd) assay has significantly (p = 0.0026) superior diagnostic accuracy for GD and PT, compared to that of pTRAb(2nd) assay.

[Subacute thyroiditis in woman presenting with thyrotropin-secreting pituitary adenoma]

Thyrotropin secreting tumors constitute 0,9 to 2,8% of all pituitary tumors. Thus, it is very rare tumor of this endocrine gland. Standards of the diagnosis of TSH-omas are based on me lack of inhibition of TSH levels in the presence of increased free thyroid hormones and abnormal, neoplastic intrasellar or parasellar mass. The additional criterion is lack of response of TSH after TRH stimulation. The proper treatment is surgical excision (selective adenomectomy) by the transsphenoidal route. In this paper we report the case presenting TSH-oma and consecutive subacute thyroiditis.

[Pharyngitis, massive ESR elevation and hyperthyroidism in a 71-year-old female patient]

We present a 71-year-old female patient suffering from a sore throat with unilateral neck swelling, pain on swallowing, subfebrile temperatures and general fatigue persisting for several weeks without any clinical signs of hyperthyroidism, although laboratory findings show high concentrations of T(3) and T(4) and a low TSH. A massive ESR elevation is found as well. Ultrasound reveals an inhomogeneous pattern of the thyroid gland with low echogenicity. (99m)Tc pertechnetate uptake is suppressed. The diagnosis of acute/subacute thyroiditis de Quervain is concluded. Therapeutic application of prednisone leads to a swift improvement, yet two weeks later asymptomatic hypothyroidism is diagnosed, requiring substitution of thyroxine. We discuss de Quervain's thyroiditis and the differential diagnosis of inflammatory disorders of the thyroid gland.

[Clinical validity of anti-thyroperoxidase antibody and anti-thyroglobulin antibody]

OBJECTIVE

To evaluate the clinical validity of anti-thyroperoxidase antibody (anti-TPOAb) and anti-thyroglobulin antibody (anti-TgAb).

METHOD

Serum levels of anti-TPOAb and anti-TgAb were assayed using chemiluminescence immunoassay in 434 subjects, including 51 patients with Hashimoto's thyroiditis, 58 with Graves' disease, 68 with nodular goiter, 56 with thyroid adenoma and carcinoma, 56 with subacute thyroiditis, 65 with euthyroid non-thyroid endocrine disease, 35 with euthyroid non-thyroid autoimmune diseases, and 45 euthyroid controls.

RESULTS

The highest level and most positive results of serum anti-TgAb and anti-TPOAb were observed in patients with Hashimoto's thyroiditis (median 373 and 6 974 U/ml, positive rate 84.3% and 86.3%), followed by patients with Graves' disease (median 84 and 1 369 U/ml, positive rate 44.8% and 72.4%). Serum anti-TgAb and anti-TPOAb were also more common in patients with subacute thyroiditis and other autoimmune diseases than in the controls.

CONCLUSION

The assay of serum anti-TPOAb and anti-TgAb by chemiluminescence immunoassy are useful in the differential diagnosis of autoimmune thyroid disease.

Color Doppler ultrasonography in patients with subacute thyroiditis

We studied the utility of color Doppler ultrasonography in patients with subacute thyroiditis. Eighteen patients with subacute thyroiditis (SAT) with painful goiter and thyrotoxicosis underwent color Doppler ultrasonography during the acute and recovery stages of the disease. Thyroid vascularization in these patients was compared with that of 15 untreated patients with Graves' disease and 17 control subjects. During the acute stage of subacute thyroiditis, color Doppler ultrasonography showed low echogenicity without increased tissue vascularity in the affected swollen thyroid. In the recovery stage, color Doppler ultrasonography showed isoechogenicity with slightly increased vascularization. Vascularization became normal at 1 year follow-up time. In contrast, marked by increased vascularization was observed in patients with untreated Graves' disease. Color Doppler ultrasonography showed clear differences between SAT and Graves' disease patients. Vascularity was significantly correlated with serum free thyroxine (FT4) and thyrotropin (TSH) concentrations in the recovery stage (3 months after the initial ultrasonography). Color Doppler ultrasonography accurately visualized lesions without increased vascularity in the acute stage of SAT and lesions of slightly increased vascularity in the recovery stage. Color Doppler ultrasonography may be a useful, noninvasive, and rapid method for differentiating SAT from Graves' disease and for evaluating and monitoring the location and activity of lesions in SAT.

[High alkaline phosphatase in subacute thyroiditis]

Subacute thyroiditis may be hard to diagnose, therefore patients are sometimes misdiagnosed and subjected to unnecessary work-up. We report a 37-year-old man with subacute thyroiditis and a high concentration of serum alkaline phosphatase. After aspirin treatment there was clinical improvement and decrease in rapid ESR, and in high serum thyroxin and alkaline phosphatase. The increased alkaline phosphatase, seen in as many as 50% of patients, is of hepatic origin, and is not caused by high serum thyroxin. Awareness of this relationship may help in diagnosis and may prevent unnecessary diagnostic procedures, which may be invasive.

Comparison of serum thyrotrophin concentrations determined by a third generation assay in patients with various types of overt and subclinical thyrotoxicosis

OBJECTIVE

Recent increases in the sensitivity of methods used to measure TSH, especially third generation assays, have enabled separation of partial from complete pituitary suppression in patients with thyrotoxicosis. We have investigated the use of a sensitive chemiluminescent enzymeimmunoassay in the differential diagnosis of thyrotoxicosis.

DESIGN AND PATIENTS

Serum TSH concentrations were determined by chemiluminescent enzymeimmunoassay in patients with various types of overt and subclinical thyrotoxicosis.

RESULTS

The assay was highly sensitive with an analytical sensitivity of 0.0016 mU/l. Among 45 hyperthyroid patients with untreated Graves' disease, 37 (82.2%) showed undetectably low levels (< 0.002 mU/l). Serum TSH in the remaining 8 patients (17.8%) was 0.003-0.005 mU/l. In contrast, TSH was undetectably low in only 5 (20.0%) of 20 patients with painless thyroiditis and in 2 (12.5%) of 16 patients with subacute thyroiditis. Eleven (55.0%) with painless thyroiditis and 12 (75.0%) with subacute thyroiditis had TSH values greater than 0.005 mU/l (0.006-0.032 and 0.006-0.228 mU/l, respectively; normal range 0.5-5.0 mU/l). Serum TSH levels were subnormal in 10 of 12 patients with euthyroid ophthalmic Graves' disease, including 4 with undetectably low levels. Among 11 patients with an autonomously functioning thyroid nodule 6, including 1 with normal free T4 and free T3 and 2 with normal free T3, showed TSH values less than 0.002 mU/l. No significant correlation was observed between serum free T4 or free T3 and TSH concentrations in thyrotoxic patients. Together with the incomplete suppression of TSH observed in those with destructive thyroiditis, this suggests that the grade of TSH suppression was influenced by the duration of illness at the time of blood sampling.

CONCLUSION

The third-generation TSH assay is useful for the differential diagnosis of various types of thyrotoxicosis, especially between Graves' disease and destructive thyroiditis.

Normal serum concentrations of sex hormone binding-globulin in patients with hyperthyroidism due to subacute thyroiditis

Serum concentrations of sex hormone binding-globulin (SHBG) were determined in patients with hyperthyroidism (n = 94; 12 men, 82 women) due to either Graves' disease (n = 59; 11 men, 48 women), autonomous thyroid adenomas (n = 23; 1 man, 22 women), or subacute thyroiditis (n = 12; all women). Elevated serum concentrations of SHBG were initially seen in 57 of 82 patients (69%) with hyperthyroidism due to either Graves's disease or due to autonomous adenoma. Elevated serum SHBG concentration was more frequent in patients with serum total thyroxine (TT4) concentrations greater than 15.0 microg/dL (32/39 [82%]; including 3 patients with autonomous adenoma) compared to those with serum TT4 concentration between 11.0 and 15.0 microg/dL (21/27 [77%]; including 7 patients with autonomous adenoma), or patients with an isolated elevation of serum total triiodothyronine (TT3) concentration (4/16 [25%]; including 2 patients with autonomous adenoma). Serum SHBG concentration normalized when patients became euthyroid. Only 1 of 12 patients in the hyperthyroid phase of subacute thyroiditis had an elevated serum concentration of SHBG. Serum concentrations of thyroid binding globulin (TBG) and transcortin (CBG) were normal in all but 1 patient. In patients with hyperthyroidism as a result of Graves' disease or autonomous adenoma serum SHBG concentrations were elevated with the greatest elevation found in patients with the highest serum T4 concentrations. The normal concentrations of SHBG in the hyperthyroid phase of subacute thyroiditis most likely reflects the shorter duration of exposure to increased thyroid hormone in this condition.

Analyses of the molecular forms of serum thyroglobulin from patients with Graves' disease, subacute thyroiditis or differentiated thyroid cancer by velocity sedimentation on sucrose gradient and Western blot

Serum thyroglobulin (Tg) concentration increases in diverse thyroid pathophysiological situations. We examined whether Tg molecules appearing in the serum of patients with Graves' disease (GD), subacute thyroiditis (ST) or differentiated thyroid cancer (DTC) have distinctive biochemical properties. We used ultracentrifugation on sucrose gradient and Western blot to analyze structural parameters of immunoreactive Tg in complete serum from 40 patients with GD, ST or DTC. Purified human Tg was used as reference. Immunoreactive Tg from ST or DTC sera sedimented in a single, rather symmetrical peak as purified 19S Tg. In GD sera without detectable anti-Tg autoantibodies (TgaAb), about 80% of immunoreactive Tg was recovered in a Tg dimer peak that often split into two components; the remaining Tg immunoreactivity (10-30%) sedimented faster and was polydispersed. In GD sera containing TgaAb, immunoreactive Tg was recovered in a peak sedimenting faster than 19S Tg corresponding to immune complexes identified by protein A adsorption. Using a Western blot procedure, optimized to detect 0.1 ng Tg in serum. a single band of Tg, migrating as the intact Tg subunit, was always found in non-reducing conditions; the intensity of the band correlated with the immunoassayable Tg concentration. In reducing conditions, the Tg band obtained with GD or ST sera was decreased by up to 70% compared with that of purified Tg or serum Tg from patients with DTC. In conclusion, serum Tg from DTC is remarkably homogeneous and in the form of dimers dissociable into uncleaved monomers. In contrast, serum Tg from GD or ST is heterogeneous with respect to its sedimentation properties and/or the structural integrity of its polypeptide chains. These data provide information on the processes whereby Tg is released into the circulation.

Failure in detection of Epstein-Barr virus and cytomegalovirus in specimen obtained by fine needle aspiration biopsy of thyroid in patients with subacute thyroiditis

To study the possible role of viral infection in the etiology of subacute thyroiditis (SAT), we measured serum virus-specific antibodies to measles, rubella, mumps, type I herpes, chicken pox, human parvovirus B19 and cytomegalovirus (CMV) in 10 patients with SAT during the course of illness. In spite of the presence of IgG to each virus in more than 70% of patients, no significant changes in the IgG titers were observed except those to measles, rubella, chicken pox or CMV in only 10% of patients, respectively. Then we examined the presence of virus DNA in specimens of 9 patients with SAT obtained by fine-needle aspiration biopsy (FNAB) of the thyroid. DNA was amplified to detect that of Epstein-Barr virus and CMV by polymerase chain reaction. However, none of them were detected in all the specimens. Whereas previous studies suggest the involvement of viral infection in the pathogenesis of SAT, we failed to demonstrate significant changes in serum antiviral antibody titers or to detect viral DNA in the specimens obtained by FNAB of the thyroid. Thus further studies are clearly required to establish the definite role of viral infection in the pathogenesis of SAT.

Plasma selectin levels in patients with Graves' disease

Adhesion molecules relate to cell invasion of autoimmune thyroid disease. We studied plasma soluble P-Selectin (platelet activation-dependent granule-external membrane protein), E-Selectin (endothelial leukocyte adhesion molecule) and L-Selectin (leukocyte endothelial cell adhesion molecule-1) levels in patients with Graves' disease before and during methimazole treatment. Plasma P-, E- and L-Selectin levels in patients with untreated Graves' disease were significantly higher than those in normal subjects. Plasma P-Selectin levels decreased when their thyroid functions were normal for more than 6 months after the start of methimazole treatment. No significant change in plasma E- and L-Selectin levels in patients with Graves' disease was found between hyperthyroid state and euthyroid state after the start of methimazole treatment, but plasma L-Selectin levels in patients with untreated Graves' disease were significantly lower than those in the patients in the first euthyroid state. There was no significant correlation between plasma P-Selectin levels and serum FT4 levels, nor between plasma P-Selectin levels and serum FT3 levels. These results suggested that thyroid hormones might reflect expression of P-, L- and E-Selectin from endothelial cells, or lymphocytes, or platelets in patients with Graves' disease.

Soluble intercellular adhesion molecule-1 concentrations in patients with subacute thyroiditis and in patients with Graves' disease with or without ophthalmopathy

Increased circulating soluble ICAM-1 (sICAM-1) levels has been previously reported in Graves' disease (GD) patients with or without ophthalmopathy (GO) and in patients with toxic nodular goiter but not in patients with subacute thyroiditis. Conflicting results have also been reported about the usefulness of sICAM-1 levels as a marker for the activity of hyperthyroidism. We have therefore determined sICAM-1 levels by a sandwich enzyme linked immunosorbent assay (ELISA) method in 10 patients with subacute thyroiditis (Group 1), who are at the initial or acute phase of thyroiditis, in 10 hypothyroidic patients with Hashimoto's thyroiditis (Group 2), in 10 patients with euthyroid nodular goiter (Group 3), in 10 patients with untreated GD patients with active ophthalmopathy (Group 4), in 10 hyperthyroid GD patients without clinical ophthalmopathy (Group 5), in 10 patients with GO who are euthyroid and treated with glucocorticoids for 3 months (Group 6) and in 20 normal subjects (Control Group). Groups 1,2,4,5 and 6 (P < 0.00001 for Groups 1,4,5,6 and P < 0.05 for Group 2) but not Group 3 showed increased sICAM-1 levels compared with the control group. However Groups 4 and 6 (patient with GO) showed significantly higher sICAM-1 levels (P = 0.0003 for Group 4 and P = 0.00013 for Group 6) than Group 5. Furthermore Group 4 showed slightly but not significantly higher sICAM-1 levels than Group 6. Mean sICAM levels were significantly decreased 3 months after glucocorticoid treatment (Group 6), but had not returned to normal levels. Three patients did not respond to steroid therapy and their sICAM-1 levels were not decreased. We concluded that patients with GO with or without hyperthyroidism and patients with subacute thyroiditis have elevated sICAM-1 levels. Moreover, sICAM-1 levels reflect the degree of inflammatory activity in the thyroid gland or orbital tissue independent of the thyroidal status, since we found elevated levels in both hyperthyroidism and hypothyroidism.

Incidence of subacute thyroiditis recurrences after a prolonged latency: 24-year survey

Subacute thyroiditis, which is considered to be a viral disease, rarely recurs after a complete recovery. We evaluated data on 3,344 patients with subacute thyroiditis who were seen at Ito Hospital between 1970 and 1993. Subacute thyroiditis recurred in 48 of 3,344 patients 14.5 +/- 4.5 yr after the first episode. Five patients experienced a third episode 7.6 +/- 2.4 yr after the second. The mean age of the patients at the first, second, and third episode was 38.4 +/- 6.3, 53.1 +/- 8.9, and 57.8 +/- 10.1 yr old, respectively. The mean incidence of a recurrence was 2.3 +/- 0.9% per year. The erythrocyte sedimentation rate and the duration of treatment were each significantly decreased at the second episode as compared with the first. Thus, recurrences of subacute thyroiditis do occur at least in 2% of patients and exhibited relatively mild clinical manifestations.

Dissociation between serum interleukin-6 rise and other parameters of disease activity in subacute thyroiditis during treatment with corticosteroid

Increased serum interleukin-6 (IL-6) concentrations have recently been reported in patients with subacute thyroiditis, possibly because of cytokine release from damaged thyroid cells. To investigate the changes in serum IL-6 concentrations in subacute thyroiditis during treatment with corticosteroid, serum IL-6 concentrations were determined by an enzyme-linked immunosorbent assay method in five patients with subacute thyroiditis. Serum IL-6 concentrations were increased moderately, and simultaneously, serum levels of T4, thyroglobulin, and C-reactive protein and erythrocyte sedimentation rate were increased markedly. The treatment with prednisolone rapidly and progressively decreased serum levels of thyroglobulin, T4, and C-reactive protein and the erythrocyte sedimentation rate. In contrast, serum IL-6 concentrations increased markedly 7 days after the treatment with prednisolone in all five patients and two of five patients showed further increases in serum IL-6 concentration on the 17th day. The rise in serum IL-6 levels in untreated patients with subacute thyroiditis in this study is compatible with previous reports. The rise in serum IL-6 levels after treatment with corticosteroid in subacute thyroiditis may reflect the dissociation between the persistent release of IL-6 from the damaged thyroid cells, immediate inhibition of secondary inflammatory reactions by corticosteroid, and the release of thyroglobulin and T4 from performed colloid stores in follicular lumen destroyed by subacute thyroiditis.

Acute spontaneous hemorrhagic degeneration of the thyroid nodule with subacute thyroiditis-like symptoms and laboratory findings

Seventeen consecutive patients (3 men and 14 women, aged 14-75 years) with a hemorrhagic degeneration of the thyroid nodule, which was confirmed by both ultrasonography and either reddish or brown fluid evacuated by fine-needle aspiration, were classified as either acute type with an episode of abrupt painful swelling of the thyroid (n = 4), or chronic type in which a painless thyroid nodule was incidentally found (n = 13). One of the four acute type patients demonstrated subacute thyroiditis-like symptoms and laboratory findings including transient painful thyrotoxicosis associated with high serum levels of thyroid hormones and thyroglobulin (Tg), a suppressed serum TSH level, a low thyroidal radioactive iodine uptake (RAIU), and accelerated erythrocyte sedimentation rate (ESR). In the other three acute type patients the serum level of Tg increased markedly, the serum thyroid hormones level increased in one, the thyroidal RAIU was low in two, and the ESR was accelerated in one. In the thirteen chronic type patients, the serum levels of the thyroid hormones and the thyroidal RAIU were within the normal range, and few inflammatory signs were observed. These findings suggest that acute hemorrhagic degeneration of the thyroid nodule may thus cause transient subacute thyroiditis-like symptoms and laboratory findings.

Use of sodium ipodate in management of hyperthyroidism in subacute thyroiditis

Five hyperthyroid patients (two men and three women) with typical features of subacute thyroiditis were treated with sodium ipodate (Oragrafin; 0.5 g, orally daily or every other day) for 15-60 days; the treatment was stopped when both serum T4 and T3 levels were normal. All patients studied demonstrated a prompt normalization of serum T3, improvement in clinical symptoms of hyperthyroidism, and/or weight gain. We observed no side-effects of treatment with sodium ipodate. Our data suggest that sodium ipodate is a safe and effective agent for management of hyperthyroidism in subacute thyroiditis.

Effect of thyrotropin-releasing hormone on serum thyroid hormones: a study in the patients with untreated and treated Graves' disease and subacute thyroiditis

In order to investigate the extrapituitary action of TRH on the thyroid, serum T3, T4, and TSH levels after im administration of TRH were analyzed in 63 patients with untreated hyperthyroid Graves' disease, in 60 euthyroid patients with treated Graves' disease, in 8 patients with subacute thyroiditis, and in 140 healthy subjects. TRH administration in the healthy subjects resulted in a significant increase in serum T3 and T4 levels after 2 h. However, in the patients with untreated hyperthyroid Graves' disease, a significant decrease in serum T3 and T4 levels with undetectable TSH was found 2 h after TRH administration. In the patients with subacute thyroiditis, serum T3 levels also significantly decreased after TRH administration. When a decrease in serum T3 and T4 levels after TRH administration in the patients with hyperthyroid Graves' disease was analyzed in terms of thyroid microsomal antibody and thyroglobulin antibody, a decrease in serum T3 and T4 levels was largest in patients with thyroid microsomal antibody and thyroglobulin antibody. In contrast, an increase in serum T3 and T4 levels in response to TRH in the euthyroid patients with Graves' disease was largest in patients without thyroid autoantibodies. It is concluded that TRH acts directly on the thyroid to suppress the thyroid hormone secreting activity in the absence of circulating TSH and that thyroid autoantibodies affect thyroidal response after TRH administration.

Serum concentrations of granulocyte colony-stimulating factor (G-CSF) determined by a highly-sensitive chemiluminescent immunoassay during the clinical course of subacute thyroiditis

Granulocyte colony-stimulating factor (G-CSF) concentrations in serum were determined for the first time by a newly developed and highly sensitive chemiluminescent immunoassay (the limitation of detection, 0.5 pg/ml) in ten patients with subacute thyroiditis, during treatment with glucocorticoid or indomethacin. Before therapy, circulating neurophil counts significantly increased to 5.15 +/- 2.07 x 10(3)/microliters compared with the convalescent phase (2.94 +/- 1.07 x 10(3)/microliters), and the data were correlated with individual serum G-CSF levels (r = 0.854, P < 0.01). Serum concentrations of interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) were less than the detectable threshold of ELISA. During two weeks of glucocorticoid therapy, although the circulating neutrophil counts increased from 5.15 +/- 2.46 x 10(3)/microliters to 7.73 +/- 1.64 x 10(3)/microliters (P < 0.01), serum G-CSF levels were depressed from 25.1 +/- 15.3 pg/ml to 13.8 +/- 13.9 pg/ml (P < 0.01). These data indicate that G-CSF is one of the mediators of the increase of neutrophils in subacute thyroiditis, while it does not contribute to steroid-induced neutrophilia.

[Steroid therapy and course of blood sedimentation rate in de Quervain's thyroiditis]

This study presents a retrospective analysis of clinical and laboratory results of 22 patients--predominantly younger women--with thyroiditis de Quervain. Diagnosis is based on clear leading symptoms like swelling and tenderness of the thyroid on pressure, swallowing with pain radiating to mandible and/or ears, fever and increased erythrocyte sedimentation rate (ESR). Half of the patients had slight anemia, leucocytosis without shift to the left, lymphopenia and thrombocytosis. The therapy of choice was prednisone, starting with an initial dose of usually 50 mg, reduced stepwise over 3 months under control of the clinical picture and the sedimentation rate. In a third of the patients clinical symptoms of the disease that had disappeared transiently redeveloped under reduction of prednisone without increase of the erythrocyte sedimentation rate. Raising the dose of prednisone for a short while led to prompt disappearance of symptoms. The ESR thus supports diagnostic investigations; however, it fails as a control parameter for the course of disease under treatment.

Glucose metabolism in a patient with hyperthyroidism and an insulinoma

A 67-year-old woman was admitted in hypoglycemic coma, with fever and signs of hyperthyroidism. Diagnosis was made of both an insulinoma and subacute ("De Quervain") thyroiditis. This rare coincidence of two diseases with opposite effects on serum glucose levels, offered a rare opportunity to study glucose metabolism in this peculiar physiopathological situation. During the day abnormally high postprandial blood glucose levels were seen, pointing to the glucose intolerance usually seen in the hyperthyroid state. During the night and after prolonged fasting, however, hypoglycemia predominated, consistent with the clinical picture typical of an insulinoma. After resection of the insulinoma and spontaneous healing of hyperthyroidism, glucose metabolism reverted to normal. As shown in this case, concurrent hyperthyroidism and an insulinoma may lead to consecutive episodes of glucose intolerance and hypoglycemia within the same 24-hour period.

Increased serum interleukin-6 concentration in patients with subacute thyroiditis: relationship with concomitant changes in serum T4-binding globulin concentration

Interleukin-6 (IL-6) is the main mediator of the acute phase response. Increased serum concentrations of the cytokine have been found in patients with nonthyroidal inflammatory disorders and infections. In 18 patients with subacute thyroiditis (SAT) evaluated within 1-2 weeks after the onset of the disease, serum IL-6 values, as assessed by an ELISA method having a limit of detection of 25 fmol/L, ranged 139.2-543.9 fmol/L (mean +/- SE, 287.2 +/- 28.2 fmol/L). These values were significantly higher than those of 25 normal healthy controls (mean +/- SE, 26.2 +/- 5.5 fmol/L, range < 25-99.4), 18 of whom had serum IL-6 values below the detection limit. The increase in serum IL-6 levels in SAT patients appeared to be related to the inflammatory disorder and not to thyrotoxicosis, because 18 Graves' disease patients and 13 patients with toxic adenoma or toxic multinodular goiter had significantly lower serum IL-6 concentrations (101.7 +/- 35.2 fmol/L, range < 25-251, for Graves' disease, 79.6 +/- 41.4 fmol/L, range < 25-168.5, for toxic adenoma, p < 0.001 vs SAT for both groups) despite the markedly higher levels of total and free thyroid hormones. Neither free T4 nor free T3 values were correlated with serum IL-6 levels both in SAT and Graves' patients. Twelve SAT patients were reevaluated 3-4 months later, after remission of the disease and at least one month after glucocorticoid withdrawal. At the final observation, all SAT patients showed a normalization of IL-6 concentration, which was undetectable in 8/12 (mean +/- SE, 22.8 +/- 5.4 fmol/L, p < 0.001 vs acute phase values).(ABSTRACT TRUNCATED AT 250 WORDS)

Serum sialic acid levels in the diagnosis and follow-up of subacute granulomatous thyroiditis

To evaluate the usefulness of monitoring serum sialic acid (SA) levels for diagnosis and follow-up of subacute granulomatous thyroiditis (SAT), 43 patients were studied at our clinic. In the acute phase of the disease their SA levels averaged 104.9 +/- 19.7 mg/dl (normal 44-69 mg/dl). In the recovery phase SA levels returned to a range of 60.5 +/- 6.9 mg/dl. However, an increase in SA (87.4 +/- 18.2 mg/dl) was detected at the time of recurrence in 14 patients. In 29 non-recurrent patients, serum SA gradually reduced during the course of therapy and normalized in all patients by the time glucocorticoid therapy was discontinued. Thyroglobulin (Tg) and the erythrocyte sedimentation rate (ESR), however, had normalized in only half the cases even at the time of cessation of therapy (Tg 5/11, ESR 4/8). C-reactive protein (CRP) returned to negative in most patients (19/24) only one week after initiation of the therapy. These results suggested that the monitoring of SA levels can be a useful tool in diagnosis and follow-up of SAT.

Serum concentrations of osteocalcin in patients with hyperthyroidism, hypothyroidism and subacute thyroiditis

Serum concentration of osteocalcin (OC) was measured in sera from untreated patients with Graves' disease, hypothyroidism due to Hashimoto's thyroiditis, and subacute thyroiditis. Serum concentration of OC in Graves' disease and hypothyroidism were 14.1 +/- 5.6 micrograms/L and 3.8 +/- 2.7 micrograms/L, respectively which were significantly different from that of healthy subjects (Graves' disease, p less than 0.001, hypothyroidism, p less than 0.01). Serum concentration of OC in patients with subacute thyroiditis was 8.0 +/- 3.5 micrograms/L which was not statistically different from age-matched normal controls. Serial measurement of serum OC for 24 mo in 15 patients with Graves' disease after initiation of antithyroid drugs disclosed that the decline of serum OC was obtained only 24 mo after antithyroid drug therapy. On the other hand, in hypothyroid patients, increased serum OC was observed after 1-2 months treatment of L-T4. Correlation coefficients between serum concentrations of OC and T3, T4, FT3 or FT4 in all the patients with thyroid disorders were 0.66, 0.51, 0.50 and 0.54, respectively, which were statistically significant (all, p less than 0.001). These results suggest that osteoblastic activity is enhanced in hyperthyroidism and suppressed in hypothyroidism. In hyperthyroid patients, despite of normalization of FT4 concentration in relatively short period (within 3-4 mo), it took 24 mo after initiation of antithyroid drugs for OC to normalize, suggesting not only thyroid hormone per se but also some unknown factor(s) participates in serum OC secretion. In contrast to thyrotoxic patients, rapid increase in serum OC after initiation of supplemental L-T4 treatment in hypothyroidism was observed, suggesting a direct effect of thyroid hormone on the osteoblasts in patients with hypothyroidism.

Thyroid ultrasonography related to clinical and laboratory findings in patients with silent thyroiditis

We summarized the clinical course of 10 patients with silent thyroiditis and evaluated the clinical usefulness of ultrasonography, in combination with clinical and laboratory findings, for the differentiation from Graves' disease. Serum T3 and T4 were increased in all cases, and the ratio of T3/T4 (ng/micrograms) was 17.8 +/- 3.6 (SD). But in 3 of 10 patients the ratio was greater that 20. TSH receptor antibody (TRAb) and thyroid stimulating antibody (TSAb) were negative in all cases. The estimated thyroid volume by ultrasonography was 18.4 +/- 5.5 ml, which was slightly increased but significantly lower than those in Graves' disease (p less than 0.05). The internal texture of the thyroid showed a decreased echogenicity with a mean echo level of 70.4 +/- 15.4. There was a weak positive correlation between the echo level at the onset of thyrotoxicosis and the lowest T3 level during the clinical course (p less than 0.05). It is suggested that ultrasonography gives a useful information to the diagnosis and outcome of patients with silent thyroiditis.

The incidence of thyroid stimulating blocking antibodies during the hypothyroid phase in patients with subacute thyroiditis

The etiology of subacute (de Quervain's) thyroiditis (SAT) is uncertain, although it probably represents a nonspecific inflammatory response by the thyroid to a variety of viruses. It has been suggested that nonimmune processes are involved in SAT patients who have negative autoantibody titers. The disease has a variable course; although it is self-limited in most cases, some patients develop transient hypothyroidism, and others do not during the recovery period. The present study was performed to evaluate the occurrence of TSH receptor antibody (TRAb), measured by RRA (TSH binding inhibitor), TRAb measured by stimulation assay (thyroid-stimulating antibody), and TRAb measured by blocking assay [TSH-blocking antibody (TSH-BAb)] activity in 68 patients with SAT who had negative autoantibody titers. The patients were divided into 2 groups: group I, 31 patients who developed hypothyroidism during the recovery period; and group II, 37 patients who remained euthyroid during recovery. Positive immunoglobulin activity occurred in about 20% of group I patients during follow-up, but in only 3% of group II patients. About 20% of group I patients developed positive TSH-BAb activity and were hypothyroid, requiring exogenous hormone therapy for 1.2-3.5 yr, whereas hypothyroidism was relatively transient in group I patients who had negative TSH-BAb activity (2-6 months). Although increased TSH-BAb activity may account for hypothyroidism in some patients with SAT, the precise mechanism for the development of transient hypothyroidism in SAT remains enigmatic.

The influence of immunosuppressive acidic protein on the activity of peripheral K-lymphocytes in subacute thyroiditis

We previously reported that immunosuppressive acidic protein (IAP), an alpha 1-acid glycoprotein, is increased during the acute phase of subacute thyroiditis (SAT). In this study we measured the percentage and absolute number of peripheral K-cells using a plaque-forming cell technique to investigate immunological abnormalities associated with SAT. Additionally, we investigated the relationship between IAP and peripheral K-cell activity. In normal controls, a sex-related difference in the percentage of K-cells among total lymphocytes was present; the percentage was significantly lower in women (mean +/- SD, 5.0 +/- 2.0%; n = 12; P less than 0.01) than in men (8.4 +/- 2.9%; n = 13). However, there was no difference (0.153 +/- 0.073 x 10(9)/L in five females; 0.173 +/- 0.054 x 10(9)/L in seven males) in the absolute number of peripheral K-cells. During the acute phase of SAT, the percentage (2.4 +/- 1.9% in 16 females; 2.7 +/- 1.0% in 3 males) and absolute number (0.058 +/- 0.048 x 10(9)/L in 11 females) of K-cells were significantly lower than those in normal controls. These values returned to normal during the recovery phase, although their mean values were still lower than those in normal controls. In female patients with Graves' disease, the percentage (2.2 +/- 1.8% in 11 females) and absolute number (0.038 +/- 0.033 x 10(9)/L in 11 females) of K-cells were significantly lower than those in normal controls; in male patients, the percentage (4.2 +/- 2.7% in 5 males) was lower than that in normal controls, but the absolute number (0.136 +/- 0.114 x 10(9)/L) of K-cells was not significantly different. Serum IAP values during the acute phase of SAT showed a significant negative correlation with the percentage of K-cells (r = -0.66; P less than 0.01). The number of K-cells from a normal subject decreased significantly when these lymphocytes were incubated with sera from patients with SAT, and the mean inhibition rate of K-cells by serum samples from 13 SAT patients during the acute phase was higher than that during the recovery phase (68.0 +/- 21.0 vs. 38.0 +/- 23.0%; P less than 0.01). Purified IAP inhibited the activity of K-cells from normal subjects dose dependently. These results suggest that 1) there may be inhibitory factors for the antibody-dependent cell-mediated cytotoxicity of peripheral K-cells in the serum of patients with SAT, and 2) IAP may be one of these inhibitory factors.

[Lymphocyte subpopulations and the soluble interleukin-2 receptor in Hashimoto's thyroiditis and subacute thyroiditis]

There are no univocal experimental data in literature about T cell clone alterations in the peripheral blood during Hashimoto's thyroiditis (TH), autoimmune disease, and during subacute thyroiditis (TSA), an inflammatory thyroid lesion with possibility of "self-perpetuation". The object of our research was to examine the T cell clones, soluble fraction of interleukin 2 receptor and HLA-DR modifications in patients with TH and TSA compared with healthy population. Our results show significant increase of sIL-2r in the TSA compared with normal subjects and with patients TH, where on the contrary, a constant increase of HLA-DR was observed.

Erythrocyte zinc concentration in patients with subacute thyroiditis

We have recently reported that red blood cell (RBC) zinc (Zn) in patients with hyperthyroidism reflects a patient's integrated thyroid hormone level over the previous few months. In the present paper RBC Zn concentrations were measured in 10 patients with subacute thyroiditis whose total plasma T4 and T3 levels were elevated. The values were compared with those obtained in 10 patients with untreated Graves' disease, whose plasma T4 concentrations were elevated to the same level as in the former group. The RBC Zn concentration was normal in 9 of 10 patients with subacute thyroiditis, but was depressed in all patients with Graves' disease. The mean (+/- SE) RBC Zn in patients with subacute thyroiditis was 162 +/- 9 mumol/L, significantly (P less than 0.001) higher than that in Graves' disease (87 +/- 5 mumol/L). During prednisolone treatment the RBC Zn in patients with subacute thyroiditis remained at the normal level and did not change significantly, although it was slightly decreased at 2 and 4 weeks of treatment. On the other hand, the RBC Zn in patients with Graves' disease was significantly increased at 8 weeks of treatment and reached the normal range in 12 weeks. These results suggest that elevation of plasma thyroid hormone concentrations in patients with subacute thyroiditis is transient and does not cause any significant change in the RBC Zn concentration.

Erythrocyte zinc concentrations in subacute (de Quervain's) thyroiditis

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