Cardiac troponin T is not increased in patients with hypothyroidism.

Patients with hypothyroidism often have increased creatine kinase (CK) levels. It is possible that there is increased production of CK, but other mechanisms, such as an increased cell membrane permeability or decreased enzyme clearance were also proposed. Recently, troponins T and I have been extensively studied because of their cardiac specificity. Cardiac troponins are sensitive and specific markers of cardiac injury. The objective of the study was to measure cardiac troponin T (cTnT) levels in patients with hypothyroidism. Twenty-five patients with primary hypothyroidism were evaluated (thyroid-stimulating hormone (TSH) >30 mU/L and low FT(4)). In all patients thyrotropin (TSH), free thyroxine (FT(4)), CK, CK-MB and cTnT were measured.There were 3 men and 22 women with a mean age of 47.5 +/- 12.4 years. TSH levels ranged from 31 to 75 mIU/L and mean FT(4) levels were 4.5 +/- 1.9 pmol/L. CK was normal in 11 patients and increased in 14. CK levels ranged between 86 and 1221 U/L (normal levels <170 in women, <195 in men) with a mean of 322 U/L +/- 279. CK-MB was increased in 4 patients (16%) and normal in 21. All 25 patients had normal cTnT levels, < 0.01 ng/mL (normal levels 0-0.1 microg/L). Increase in CK and its MB fraction are common in patients with hypothyroidism but cTnT levels are not, even in patients with increased CK-MB. Therefore, cTnT is a reliable marker of cardiac injury even in the hypothyroid patient.

Newly diagnosed thyrotoxicosis in hospitalized patients: clinical characteristics.

BACKGROUND: Thyrotoxicosis is often diagnosed in an outpatient setting. The most common symptoms include irritability, heat intolerance, palpitations and weakness. Sometimes, however, thyrotoxicosis is first diagnosed in the hospital setting. The prevalent symptoms in hospitalized patients with newly diagnosed thyrotoxicosis have not been fully characterized. AIM: To determine the clinical characteristics of patients with thyrotoxicosis newly diagnosed during hospitalization. DESIGN: A retrospective computer-based search was undertaken to detect patients that were hospitalized in our medical centre during 1999-2006, and discharged with thyrotoxicosis or thyroiditis as the primary diagnosis. RESULTS: Fifty-eight patients (36F/22M; mean age 52.1 +/- 17.5 years) were identified. Weakness, weight loss and palpitations were the most common manifestations (50, 40 and 35%, respectively) and were predominantly present in patients with hyperthyroidism. Sore throat was present in 41% of patients with thyroiditis. Sinus tachycardia and atrial fibrillation occurred in 65.5 and 15.5% of the patients, more common in those with hyperthyroidism. The diagnoses on discharge were Graves' disease, subacute thyroiditis and multinodular goiter in 39.7, 34.5 and 8.9%, respectively. CONCLUSION: Weakness, weight loss and palpitations were the main symptoms in patients diagnosed with thyrotoxicosis during hospitalization. Thyrotoxicosis should be included in the differential diagnosis when patients are admitted to the hospital with those symptoms.

Clinical relevance of non-palpable thyroid nodules as assessed by ultrasound-guided fine needle aspiration biopsy.

It is known from autopsy data that thyroid nodules are far more common than can be detected by palpation alone. With the wide use of modern non-invasive imaging many non-palpable thyroid nodules are discovered but the proper approach to these nodules is still debatable. In a retrospective study, we reviewed the data from 186 US-guided FNA biopsies (US-FNAB) performed between May 1995 and March 1997 at the Sapir Medical Center, Israel, a iodine-sufficient urban area. Sixty-one of the 186 US-FNAB of the thyroid were performed in non-palpable nodules. The mean size of these nodules was 2.4 +/- 1.0 cm (mean +/- SD) ranging from 1.1-5.5 cm. Description of the nodule consistency was available in 53 cases; 42/53 were solid and 11/53 were solid-cystic. FNAB was diagnostic in 46 patients and non-diagnostic in 15. Forty-three of the diagnostic cytology reports were benign, one revealed papillary carcinoma, one had suspicious findings and the third was suspicious for a follicular neoplasm. The last two patients were referred to surgery and a follicular adenoma was found in both. Among the 61 non-palpable thyroid nodules, only one was papillary carcinoma, a prevalence of 1.6%. The other two patients referred to surgery had benign lesions. We found a low prevalence of malignancy in relatively large non-palpable thyroid nodules.

Autoimmune thyroid disease and antiphospholipid antibodies.

OBJECTIVE: Autoimmune thyroid disease (ATD) is associated with circulating autoantibodies reactive with epitopes on thyroid tissue and that are thought to be pathogenic in the development of these diseases. Antiphospholipid antibodies (APLA) are a family of immunoglobulins that recognize a variety of plasma proteins in association with anionic phospholipids. These antibodies may lead to a number of clinical syndromes including venous and arterial thromboses, thrombocytopaenia, and recurrent fetal loss. We have studied the prevalence of APLA in patients with ATD and have determined the prevalence of the APLA syndrome among APLA-positive patients. DESIGN: The study was a retrospective survey of patients with autoimmune thyroid disease attending the endocrinology clinic of a tertiary care academic hospital. PATIENTS AND MEASUREMENTS: One hundred and thirty patients with autoimmune thyroid disease from the endocrinology clinic at our hospital were studied. 84% had chronic thyroiditis and 16% had Graves' disease. Free T4 and thyroid stimulating hormone (TSH) levels, antimicrosomal and antithyroglobulin antibodies, and an antiphospholipid antibody test were performed on all subjects. RESULTS: 43% of patients with chronic thyroiditis and 43% of patients with Graves' disease were APLA positive, with an overall rate of 43% APLA positivity among patients with ATD. Of the 56 patients that were APLA positive, forty-eight (86%) had APLA of the IgG subtype, four (7%) had IgM antibodies, and nine (16%) had both IgG and IgM antibodies. None of the patients had clinical evidence of the APLA syndrome. CONCLUSIONS: We conclude that the prevalence of APLA in ATD is increased compared to healthy individuals but that this is likely to be an epiphenomenon. However, prolonged follow up is necessary in order to determine the true clinical significance of these antibodies in ATD patients.

Induction of apoptosis by chlorodeoxyadenosine and dexamethasone in B-chronic lymphocytic leukemia.

Apoptosis, programmed cell death, occurs in a variety of cellular systems and in response to many different stimuli. In the present study we examined the ability of dexamethasone (Dex) and chlorodeoxyadenosine (2-CdA) to induce apoptosis in lymphocytes of patients with B-chronic lymphocytic leukemia (B-CLL). Lymphocytes of 29 untreated patients and 9 healthy controls were isolated and incubated for 24 hours in the presence or absence of either Dex (2 microM) (n = 15) or 2-CdA (3 microM) (n = 14). Following incubation the cells were harvested and their DNA extracted and analysed for internucleosomal DNA cleavage by UV illumination after electrophoresis on agarose slab gel containing ethidium bromide. In the Dex group, 10 patients showed dexamethasone independent spontaneous apoptosis appearing 24 hours after the start of incubation. These were the only instances of dexamethasone-enhanced apoptosis. Five patients showed no spontaneous or dexamethasone induced apopto sis. Of the 2-CdA group, 5 showed spontaneous apoptosis enhanced by 2-CdA. No spontaneous apoptosis was observed in the cells from 9 other patients, however, 2-CdA induced apoptosis in 8 cases in this group. This study shows that monitoring of apoptosis in CLL may provide important information regarding susceptibility of the cells to drug induced apoptosis.