Obesity Influences T CD4 Lymphocytes Subsets Profiles in Children and Adolescent's Immune Response.

BACKGROUND: OBJECTIVES: Evidence shows that CD4+ T cells are altered in obesity and play a significant role in the systemic inflammation in adults with the disease. Because the profile of these cells is poorly understood in the pediatric population, this study aims to investigate the profile of CD4+ T lymphocytes and the plasma levels of cytokines in this population. METHODS: Using flow cytometry, we compared the expression profile of lymphocyte markers, master transcription factors, cytokines, and molecules involved in the regulation of the immune response in CD4+ T cells from children and adolescents with obesity (OB group, n = 20) with those with eutrophy group (EU group, n = 16). Plasma levels of cytokines in both groups were determined by CBA. RESULTS: The OB group presents a lower frequency of CD3+ T cells, as well as a decreased frequency of CD4+ T cells expressing CD28, IL-4, and FOXP3, but an increased frequency of CD4+IL-17A+ cells compared with the EU group. The frequency of CD28 is increased in Th2 and Treg cells in the OB group, whereas CTLA-4 is decreased in all subpopulations compared with the EU group. Furthermore, Th2, Th17, and Treg profiles can differentiate the EU and OB groups. IL-10 plasma levels are reduced in the OB group and negatively correlated with adiposity and inflammatory parameters. CONCLUSIONS: CD4+ T cells have an altered pattern of expression in children and adolescents with obesity, contributing to the inflammatory state and clinical characteristics of these patients.

Subclinical Hypothyroidism with TSH>7 mIU/l and≤10 mIU/l and Coronary Artery Disease.

The association of subclinical hypothyroidism (SCH) with increased cardiovascular risk is controversial when thyroid-stimulating hormone (TSH) concentration is<10 mIU/l, as well as its association with a higher coronary artery calcium score (CACS) in individuals with low cardiovascular risk. This study evaluated coronary artery disease (CAD) by CACS in asymptomatic, low-cardiovascular risk women with SCH and TSH>7 mIU/l and≤10 mIU/l untreated for 5 years after diagnosis. The CACS was obtained for two groups of women with low cardiovascular risk. Group A consisted of 32 women with mild SCH (TSH>7 mIU/l and≤10 mIU/l) who remained untreated for 5 years, and group B consisted of 32 euthyroid women matched for age and body mass index to group A. The CACS ranged from 0 to 350 (median 0, 25-75% interval: 0-10) in group A and from 0 to 280 (median 0, 25-75% interval: 0-0) in group B. Scores>0 and≥10 were significantly more frequent in group A (40.6 vs. 12.5% and 25 vs. 3.1%, respectively). A CACS≥100 was also more frequent in group A (18.75 vs. 3.1%), but the difference was not significant (p=0.1). The results of the study suggest that long-term SCH with TSH>7 mIU/l and ≤ 10 mIU/l is associated with a higher risk of CAD in individuals≤65 years, even in those with low cardiovascular risk.

Usefulness of Serum Calcitonin in Patients with Thyroid Nodules ≤ 1 cm Without an Indication for Fine-Needle Aspiration.

Fine-needle aspiration (FNA) is not necessary in adults with nodules ≤ 1 cm without apparent extrathyroidal extension (ETE) or lymph node (LN) involvement on ultrasonography (US). In the absence of FNA and serum calcitonin (Ctn) measurement, medullary thyroid microcarcinomas (microMTC) are not diagnosed. The aim of this prospective study was to evaluate Ctn levels in adults with a low clinical risk of MTC and nodules ≤ 1 cm without ETE or LN involvement on US. A total of 506 consecutively seen adults who had nodules with two or more suspicious features were included. Patients with elevated basal Ctn underwent a calcium stimulation test and FNA. Basal Ctn was normal in 490 patients (96.8%). In the 16 patients with elevated basal Ctn, FNA revealed MTC in only one patient and MTC was not suspected in the 15 patients with elevated basal Ctn. Three patients with stimulated Ctn<100 pg/ml and benign cytology were not submitted to surgery. MTC was excluded by histology in three patients with stimulated Ctn<100 pg/ml and indeterminate or suspicious cytology and in eight patients with stimulated Ctn>100 pg/ml. One patient with stimulated Ctn>100 pg/ml had MTC. Ctn was undetectable 6 months after surgery in two patients with MTC. Although uncommon, even subjects without a suspicious history and with nodules ≤ 1 cm without ETE or LN involvement on US, but with suspicious findings, can have microMTC. The measurement of Ctn permits the diagnosis of these cases.

Normocalcemic Primary Hyperparathyroidism in Adults Without a History of Nephrolithiasis or Fractures: A Prospective Study.

The prevalence and the diagnostic criterion of "normocalcemic" primary hyperparathyroidism (NPHPT) are still uncertain and there is no consensual definition. This prospective study evaluated the prevalence of NPHPT in 676 adults without a history of fractures or nephrolithiasis and who would be submitted to thyroidectomy, the impact of adopting different cut-off values for 25-hydroxyvitamin D and estimated glomerular filtration rate (eGFR), and the agreement between biochemical diagnosis and the surgical finding of altered parathyroid glands. NPHPT was diagnosed in patients with normal total and ionized calcium and elevated PTH (in 2 measurements) and without a known cause of secondary HPT, including eGFR<40 ml/min/1.73 m2 and 25-hydroxyvitamin D<20 ng/dl. The 4 parathyroid glands were fully explored in these patients. Forty-six patients (6.8%) had a laboratory diagnosis of NPHPT. Altered parathyroid glands were detected in only 4 patients, corresponding to 0.6% of all patients and to 8.7% of those with a biochemical diagnosis of NPHPT. The latter was confirmed in 0/174 men, 1/252 premenopausal women, and 3/250 postmenopausal women. Among the 42 patients with elevated PTH and without altered parathyroid glands, 25 had 25-hydroxyvitamin D between 20 and 30 ng/dl, 7 had eGFR between 40 and 60 ml/min/1.73 m2, and 9 had both. The prevalence of NPHPT was 0.74% in this adult population without a history of nephrolithiasis or fractures. The diagnostic criterion using eGFR>60 ml/min/1.73 m2 and 25-hydroxyvitamin D>30 ng/dl was more appropriate considering the agreement with the surgical finding of altered parathyroid glands.

Definition of the Response to Initial Therapy with Radioiodine in Patients with Differentiated Thyroid Carcinoma: Basal or Stimulated Thyroglobulin?

Basal thyroglobulin (b-Tg) measured with second-generation assay or stimulated Tg (s-Tg) can be used to define the response to therapy of differentiated thyroid carcinoma. However, they do not always define the same category and guidelines do not establish "if" or "when" s-Tg needs to be obtained. We studied 304 patients without clinically apparent disease or disease detected by neck ultrasonography and without anti-Tg antibodies 9-12 months after therapy. Based on b-Tg, 196 patients had an excellent response and 108 had an indeterminate response. Based on s-Tg, a change in category occurred in 10.2% of the patients with an initial excellent response (all to indeterminate response) and in half the patients with an initial indeterminate response (44.4% to excellent response and 5.5% to biochemical incomplete response). One case of recurrence was observed among patients with an initial excellent response but whose response changed to indeterminate after s-Tg, while no disease was detected among those who remained in the initial category; however, this difference was not significant. In patients with an initial indeterminate response, no recurrence was detected among those whose response changed to excellent after s-Tg, while 11.1 and 33.3% of those who remained in the initial category or whose response changed to biochemical incomplete, respectively, had structural disease. This study suggest that, in low- or intermediate-risk patients, s-Tg better defines the response to therapy with 131I when it is classified as indeterminate based on b-Tg using second-generation assay. However, s-Tg is not necessary when b-Tg defines the response as excellent.

Active Surveillance in Adults with Low-Risk Papillary Thyroid Microcarcinomas: A Prospective Study.

The acceptance and results of active surveillance in patients with low-risk papillary thyroid microcarcinomas (PTMC) are unknown in populations other than the Japanese population. This was the objective of the present prospective study. We selected patients ≥20 years who had thyroid nodules ≤1.2 cm with intermediate or high suspicion for malignancy on ultrasonography (US), not located near the recurrent laryngeal nerve and without extrathyroidal invasion or apparent lymph node metastases, whose cytology was suspicious (Bethesda V) or diagnostic (Bethesda VI) of papillary thyroid carcinoma. Patients who opted for active surveillance were followed up by biannual US. Fifteen patients (18.7%) readily opted for surgery and 12 (15%) for active surveillance. Fifty-three patients (66.2%) delegated the decision or wished to know the doctor's preference before deciding. After the doctor had declared his/her preference for active surveillance, 50 patients decided to have this management and three to have surgery. Only 1/70 patients exhibited tumor progression (growth associated with a suspicion of extrathyroidal invasion) after 30 months of follow-up. Two patients decided to have surgery during follow-up, although the indication was not defined by the study. A>50% reduction in tumor volume was observed in three patients. The study shows that active surveillance can be well accepted if doctors were convinced that it is the best option for patients with low-risk PTMC. At least the short-term results reproduced those observed in other populations, with tumor progression being uncommon.

Long-Term Follow-Up in Patients with Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features (NIFTP) Without a Suspicion of Persistent Disease in Postoperative Assessment.

The objective was to determine whether negative assessment after surgery is a predictor of no relevant change of the results in subsequent evaluations in patients with noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Six months after surgery, "absence of persistent disease" was defined when concentration of thyroglobulin (Tg) is ≤2 ng/ml in patients undergoing total thyroidectomy and ≤10 ng/ml in those undergoing lobectomy, in the absence of antithyroglobulin antibodies (TgAb), and neck ultrasonography (US) without abnormalities. One hundred thirteen patients met the definition of "absence of persistent disease". The patients were followed up for 18-150 months. None of the patients developed structural disease. In the 56 patients undergoing total thyroidectomy, 380 Tg measurements were obtained and an increase in concentrations was not observed in any of them. During the same period, 332 US scans were performed and a suspicious lymph node was detected on only one occasion, but was not metastatic on fine needle aspiration (FNA). In the 57 patients undergoing lobectomy, 382 Tg measurements were obtained and increases or persistent concentrations>10 ng/ml were not observed in any patient. During the same period, 376 US scans were performed and nodules with an indication for FNA were detected in 4 patients, but malignancy was not confirmed in any of them. Finally, TgAb were not elevated in any of the 762 measurements obtained from the 113 patients. After complete resection of NIFTP, negative postoperative assessment can be used to exclude the need for long-term repetition of these tests.

Ultrasonography Classification of the American Thyroid Association for Predicting Malignancy in Thyroid Nodules >1cm with Indeterminate Cytology: A Prospective Study.

The objective of this prospective study was to evaluate the ultrasonography classification of the American Thyroid Association (ATA) for predicting malignancy in thyroid nodules >1 cm with indication for fine-needle aspiration (FNA) whose cytology was indeterminate. Additionally, the combination of the ATA classification with Doppler analysis was evaluated. All patients with thyroid nodules >1 cm were eligible. Each nodule was assigned to one of the ATA categories. Exclusively or predominantly intranodular vascularity was considered suspicious. One hundred and thirty-seven patients with 143 nodules underwent FNA and those with indeterminate cytology (Bethesda category III or IV) were selected. All patients were referred for surgery. Among the 143 nodules evaluated, 92 were benign, 33 were malignant, 13 were noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP), and 5 were tumors of uncertain malignant potential (TUMP). The rate of malignancy, including NIFTP and TUMP in this definition, was 80%, 42.8%, 13%, 10%, and 23% for nodules with a high suspicion, intermediate suspicion, low suspicion, very low suspicion, and undefined ultrasonographic pattern, respectively. Considering NIFPT and TUMP as benign, these rates were 72%, 22.4%, 4.3%, 0%, and 15.4%, respectively. The addition of Doppler analysis did not significantly improve the prediction of malignancy obtained with the ATA classification alone. The results of this prospective study show the usefulness of the ATA ultrasonographic classification for predicting malignancy specifically in thyroid nodules >1 cm with indeterminate cytology. The ATA category of the nodule should influence the decision for follow-up, molecular tests, or surgery.

Natural history of subclinical hypothyroidism with TSH ≤10 mIU/l: a prospective study.

OBJECTIVE: The risk of progression of subclinical hypothyroidism (SCH) to clinical dysfunction is one of the factors considered in the decision to treat this condition. This study evaluated the natural history of SCH in women with TSH ≤10 mIU/l. DESIGN: This is a prospective study. PATIENTS: Two hundred and fifty-two women with SCH and TSH levels ranging from 4·5 to 10 mIU/l were followed up for a period of 5 years. RESULTS: Among the 241 patients followed up until the completion of the study, 46 (19%) required levothyroxine (L-T4) therapy, 55 (22·8%) had spontaneous normalization of serum TSH, and 140 (58·1%) continued to meet the criteria for mild SCH. In multivariate analysis, only initial TSH >8 mIU/l was a predictor of the need for L-T4. In contrast, initial TSH ≤8 mIU/l and the absence of thyroiditis [negative antithyroid peroxidase antibodies (TPOAb) and ultrasonography (US)] were predictors of TSH normalization. Of note, the natural history was similar in TPOAb-positive patients and patients with negative TPOAb but with positive US. CONCLUSIONS: Most women with mild elevation of serum TSH, ranging from 4·5 to 10 mIU/l, do not progress to overt hypothyroidism and even normalize their TSH. However, initial TSH seems to be a more important predictor of progression than the presence of antibodies or ultrasonographic appearance.

Can the follow-up of patients with papillary thyroid carcinoma of low and intermediate risk and excellent response to initial therapy be simplified using second-generation thyroglobulin assays?

OBJECTIVE: In view of the low probability of recurrence, the cost-effective follow-up of patients with papillary thyroid carcinoma (PTC) of low or intermediate risk and excellent response to initial therapy represents a challenge. This study evaluated the cases of structural recurrence among these patients. PATIENTS: The sample comprised 578 patients with PTC of low or intermediate risk, who were submitted to total thyroidectomy with or without (131) I therapy and exhibited an excellent response to initial therapy defined based on nonstimulated thyroglobulin (Tg) ≤0·2 ng/ml and negative neck ultrasonography (US). RESULTS: Twelve patients (2%) showed structural recurrence. At the time when recurrence was 'confirmed', Tg elevation had not occurred in only two patients, one with lymph node metastases <1 cm detected by US and the other with pulmonary metastases. Antithyroglobulin antibodies (TgAb) were undetectable in both patients. The first alteration observed in patients with recurrence was Tg elevation in six patients, Tg elevation associated with suspicious US in three, and suspicious US in two. An increase in TgAb was not the first alteration in any of the patients. Among the 560 patients who continued to have Tg ≤ 0·2 ng/ml, US permitted the detection of only one neck recurrence. Measurement of TgAb did not detect any recurrence. CONCLUSION: Our results confirm that in patients with PTC of low or intermediate risk an excellent response to initial therapy can be defined based on nonstimulated Tg ≤ 0·2 ng/ml. Follow-up consisting only of clinical examination and periodic measurement of Tg with a second-generation assay may be sufficient.

Low postoperative nonstimulated thyroglobulin as a criterion for the indication of low radioiodine activity in patients with papillary thyroid cancer of intermediate risk 'with higher risk features'.

OBJECTIVE: This study evaluated low-activity (131) I therapy in patients with papillary thyroid carcinoma (PTC) of intermediate risk 'with higher risk features' who had low nonstimulated thyroglobulin (Tg) after thyroidectomy. DESIGN AND PATIENTS: This was a prospective study including 102 patients with tumours >1 cm and aggressive histology; and/or >3 positive lymph node (LN) or LN >1·5 cm or exhibiting macroscopic extracapsular extension, and clinically apparent (cN1); and/or a combination of a tumour >4 cm, microscopic extrathyroidal extension and LN metastases (cN1). After thyroidectomy, all patients had nonstimulated Tg < 0·3 ng/ml and negative antithyroglobulin antibodies (TgAb) and neck ultrasonography (US). The patients were treated with a low activity of (131) I (1110 or 1850 MBq). RESULTS: Post-therapy whole-body scanning (RxWBS) showed ectopic uptake in four patients. When evaluated 12 months after (131) I therapy, nonstimulated Tg ≤ 0·2 ng/ml with negative TgAb and US, defined as excellent response to initial therapy, was achieved in 101 patients (99%). Only one patient with positive initial RxWBS had structural disease. During follow-up, four patients (4%) relapsed, including LN metastases in two, pulmonary metastases in one, and elevated Tg in one. The other 98 patients remained with nonstimulated Tg ≤ 0·2 ng/ml and negative TgAb and US. There was no case of death due to the tumour. CONCLUSIONS: We conclude that in intermediate-risk patients 'with higher risk features', low nonstimulated Tg measured with a second-generation assay can be used as criterion for the administration of low (131) I activities (1850 MBq or less).

Symptoms of thyrotoxicosis, bone metabolism and occult atrial fibrillation in older women with mild endogenous subclinical hyperthyroidism.

OBJECTIVE: The objective of this study was to evaluate symptoms of thyrotoxicosis, bone turnover, bone mineral density (BMD) and occult atrial fibrillation (AF) in women ≥65 years with mild endogenous subclinical hyperthyroidism (SCH). DESIGN: Cross-sectional and case-control study. PATIENTS: Signs and symptoms of thyrotoxicosis, serum carboxyterminal telopeptide (CTx) and procollagen type I N-terminal propeptide (PINP), BMD, resting electrocardiogram (ECG) and 72-h ECG monitoring were evaluated in 180 women ≥65 years, including 90 with mild SCH (TSH between 0·1 and 0·4 mIU/l) and 90 euthyroid controls matched for age and body mass index. RESULTS: Symptom Rating Scale scores did not differ between patients and controls. None of the patients with SCH scored 20 points, a score compatible with clinical thyrotoxicosis. Eighty patients with SCH (89%) obtained seven or fewer points, a score compatible with euthyroidism. No difference in serum CTx or PINP concentrations was observed between patients and controls. There was also no correlation between these markers and TSH, free T4 or total T3 levels. Finally, no difference in femoral neck or lumbar spine BMD was observed between patients with SCH and controls. Three patients with SCH (3·3%) and two euthyroid women (2·2%) had known AF or AF in the resting ECG. ECG monitoring for 72 h revealed episodes of occult AF in 1/87 patients with SCH and in 1/88 euthyroid women (1·1%). CONCLUSIONS: Mild endogenous SCH (TSH between 0·1 and 0·4 mIU/l) was not associated with symptoms of thyrotoxicosis, altered bone metabolism or a higher prevalence of occult AF in women ≥65 years.

A low postoperative nonstimulated serum thyroglobulin level excludes the presence of persistent disease in low-risk papillary thyroid cancer patients: implication for radioiodine indication.

OBJECTIVE: To evaluate the presence of persistent disease, including on post-therapy whole-body scan (RxWBS), in low-risk patients with papillary thyroid carcinoma (PTC) >1 cm who have low nonstimulated thyroglobulin (Tg) (measured with a sensitive assay), negative anti-Tg antibodies (TgAb) and neck ultrasound (US) showing no metastases after total thyroidectomy. PATIENTS: We studied 154 patients with PTC >1 cm classified as low risk, who had US without metastases, negative TgAb, nonstimulated Tg ≤ 0·25 ng/ml and TSH ≤ 2 mIU/l about 3 months after total thyroidectomy. RESULTS: Tg measured immediately before (131) I was ≤ 1 ng/ml in 89·5% of the patients and >1 ng/ml in 10·5%. None of the patients showed ectopic uptake on RxWBS. Uptake in the thyroid bed was observed in 146 (94·8%) patients and was ≤ 2% in all of them. In the control assessment 9-12 months after ablation, stimulated Tg (sTg) ≤ 1 ng/ml was achieved in 150 patients (97·4%). Only one patient had sTg >2 ng/ml (2·5 ng/ml) and none of the patients had apparent disease detected by imaging methods. During further short-term follow-up after control assessment (median of 24 months), none of the patients had tumour recurrence. CONCLUSIONS: The combination of nonstimulated Tg ≤0·25 ng/ml, negative TgAb and US without metastases after thyroidectomy rules out the presence of persistent disease (including on RxWBS) in low-risk patients with PTC >1 cm. This demonstration weakens the indication of ablation with (131) I in these cases.

Ultrasonographic differentiation of cervical lymph nodes in patients with papillary thyroid carcinoma after thyroidectomy and radioiodine ablation: a prospective study.

OBJECTIVE: The objective of the present study was to validate an ultrasound (US) classification of cervical lymph nodes (LNs) in patients with papillary thyroid cancer (PTC) after thyroidectomy and radioactive iodine (131I) ablation. METHODS: We performed a prospective study in which the patients were submitted to thyroidectomy and 131I ablation and then followed until neck US revealed LN(s) ≥5 mm. A total of 288 LNs from 112 patients with PTC were evaluated. Patient management was based on LN characteristics grouped according to the classification system studied here. RESULTS: The presence of microcalcifications and/or cystic degeneration of cervical LNs were highly suggestive of a metastatic etiology (specificity of 99.4%). In contrast, the most sensitive finding for LNs affected by PTC was the absence of an echogenic hilum (sensitivity of 100%). In the absence of these findings (microcalcifications, cystic degeneration, echogenic hilum), a metastatic etiology was the most likely in the case of a round LN (specificity of 89%). The differentiation of a spindle-shaped LN without a visible hilum by Doppler analysis permitted us to dichotomize an initial probability of metastases of 13% in 25% (with peripheral vascularization) versus 3.3% (without peripheral vascularization). CONCLUSIONS: Our results confirm that the classification proposed for cervical LNs in patients with PTC is valid for determining patient management following initial therapy.

Screening for acromegaly by application of a simple questionnaire evaluating the enlargement of extremities in adult patients seen at primary health care units.

The objective of this study was to screen for acromegaly by application of a simple questionnaire in patients seen at primary health care units. A total of 17,000 patients of both genders >18 and <70 years seen by general practitioner were interviewed. Patients with known pituitary disease and pregnant women were excluded. A simple questionnaire was applied to the patients: Has your shoe size increased over the last 5 years? Did you have to change your wedding ring or ring over the last 5 years because it became tight? In one patient, the diagnosis of acromegaly was suspected by the physician. Among the remaining patients, 178 (1%) responded positively to one of the items of the questionnaire and were submitted to IGF-1 measurement. Five patients had persistently elevated IGF-1 and inadequate suppression of GH in the OGTT (without other conditions associated with GH or IGF-1 elevation). One of these patients presented a normal pituitary upon magnetic resonance imaging and adenoma was detected in the other four; two presented the typical facies and two others reported changes in physiognomy (confirmed by the comparison of photographs), in addition to the enlargement of extremities. The present investigation suggests a much higher prevalence of acromegaly in the adult population than that reported traditionally. We propose that screening based on phenotypic alterations is cost-effective since these changes occur early and almost universally in acromegaly and are uncommon in the general population.

Can patients with papillary thyroid carcinoma and low postoperative thyroglobulin in the presence of clinically apparent lymph node metastases (cN1) be spared from radioiodine?

BACKGROUND: The study evaluated the recurrence rate in patients with papillary thyroid carcinoma (PTC) and clinically apparent lymph node metastases (LNM) (cN1) who had low thyroglobulin (Tg) after total thyroidectomy and who were not submitted to adjuvant therapy with 131I. METHODS: This was a prospective study. It included 82 cN1 patients (≤3 LNM ≤1.5 cm without macroscopic extracapsular extension) with tumors ≤4 cm without macroscopic extrathyroid invasion (T1-2) and who after thyroidectomy had unstimulated Tg (u-Tg) < 0.3 ng/ml, negative antithyroglobulin antibodies (TgAb), and neck ultrasonography (US) showing no anomalies. The patients were not submitted to therapy with 131I. RESULTS: The time of follow-up ranged from 24 to 156 months (median 84 months). Seventy-nine patients (96.3%) continued to have u-Tg < 0.3 ng/ml and negative US. Three patients (3.6%) exhibited an increase in Tg and structural recurrence was detected in two. After treatment, these patients achieved u-Tg < 1 ng/ml and the imaging methods revealed no apparent tumor. CONCLUSIONS: The results suggest that even cN1 patients, given the absence of extensive LNM or other adverse findings, who have low Tg and neck US showing no anomalies after thyroidectomy do not require radioiodine.

Serum PTH reference values in an adult Brazilian population: implications for the diagnosis of hyperparathyroidism.

OBJECTIVE: To define serum parathyroid hormone (PTH) reference values in carefully selected subjects following the recommended pre-analytical guidelines. SUBJECTS AND METHODS: First, 676 adults who would be submitted to thyroidectomy were evaluated. Patients using interfering medications or with malabsorption syndrome, hypomagnesemia, hyper- or hypophosphatemia, hypo- or hypercalcemia, 25-hydroxyvitamin D < 30 ng/dL, estimated glomerular filtration rate < 60 mL/min/1.73 m2, urinary calcium/creatinine ratio ≥ 0.25, thyroid dysfunction, parathyroid adenoma detected during surgery were excluded. The sample consisted of 312 subjects. RESULTS: The median, minimum, maximum, and 2.5th and 97.5th percentiles of the PTH values obtained were 30, 7.2, 78, 10.1, and 52 pg/mL, respectively. Thus, the reference range was 10 to 52 pg/mL. PTH > 65 pg/mL, the upper limit of normal according to the manufacturer of the kit, was observed in only one subject (0.3%). Considering the upper limit proposed by the kit's manufacturer, 1/6 hypercalcemic patients and 4/8 normocalcemic patients with PHPT had normal PTH. Using the upper limit established in this study, only one normocalcemic patient had normal PTH. Thus, the sensitivity of PTH in detecting asymptomatic primary hyperparathyroidism (PHPT) using the values recommended by the kit and established in this study was 64% and 93%, respectively (50% versus 87.5% for normocalcemic PHPT). CONCLUSION: The upper reference limit of PTH obtained for a rigorously selected sample was 20% lower than that provided by the assay, which increased its sensitivity in detecting PHPT.

Repeat Ultrasonography in the First Years after Therapy with Radioiodine Is Not Necessary in Most Patients with Papillary Thyroid Carcinoma when Postoperative Ultrasonography Is Negative: A Reduction of Costs and False-Positives.

BACKGROUND: Periodic ultrasonography (US) examination is recommended in many patients with papillary thyroid carcinoma (PTC) after treatment with radioactive iodine (RAI), but recurrences are confirmed in few cases. This study determined whether the indication of US in the first years after treatment with RAI can be selective when postoperative US and posttherapy whole-body scanning (RxWBS) ruled out persistent neck disease. METHODS: This was a prospective study. Two hundred and fifty-four patients with PTC (242 of intermediate risk) undergoing thyroidectomy and RAI, who had no apparent disease at the time of initial therapy (including negative postoperative US and RxWBS), were studied. The patients were followed up for 5 years after treatment with RAI by annual US. RESULTS: At the end of 5 years, 47 patients (18.5%) had at least one suspicious US, but neck recurrence was confirmed in only 4 patients (1.5% of all patients and 8.5% of those with suspicious US). The remaining cases were considered false-positives. US did not reveal disease in the first or second year after treatment with RAI in any patient. In the third, fourth, and fifth year after treatment with RAI, considering only patients with unstimulated Tg < 1 ng/mL in these assessments, US revealed disease in 0, 1 (0.4%), and 1 (0.4%) patient, respectively. CONCLUSION: The results suggest that low- or intermediate-risk patients with PTC without persistent disease after thyroidectomy (including negative postoperative US and RxWBS) do not require repeat US examination in the first two years after treatment with RAI. In the following years until the fifth year, US can be restricted to patients with Tg ≥1 ng/mL.