Combined molecular and mathematical analysis of long noncoding RNAs expression in fine needle aspiration biopsies as novel tool for early diagnosis of thyroid cancer

PURPOSE

In presence of indeterminate lesions by fine needle aspiration (FNA), thyroid cancer cannot always be easily diagnosed by conventional cytology. As a consequence, unnecessary removal of thyroid gland is performed in patients without cancer based on the lack of optimized diagnostic criteria. Aim of this study is identifying a molecular profile based on long noncoding RNAs (lncRNAs) expression capable to discriminate between benign and malignant nodules.

METHODS

Patients were subjected to surgery (n = 19) for cytologic suspicious thyroid nodules or to FNA biopsy (n = 135) for thyroid nodules suspicious at ultrasound. Three thyroid-specific genes (TG, TPO, and NIS), six cancer-associated lncRNAs (MALAT1, NEAT1, HOTAIR, H19, PVT1, MEG3), and two housekeeping genes (GAPDH and P0) were analyzed using Droplet Digital PCR (ddPCR).

RESULTS

Based on higher co-expression in malignant (n = 11) but not in benign (n = 8) nodules after surgery, MALAT1, PVT1 and HOTAIR were selected as putative cancer biomarkers to analyze 135 FNA samples. Cytological and histopathological data from a subset of FNA patients (n = 34) were used to define a predictive algorithm based on a Naïve Bayes classifier using co-expression of MALAT1, PVT1, HOTAIR, and cytological class. This classifier exhibited a significant separation capability between malignant and benign nodules (P < 0.0001) as well as both rule in and rule out test potential with an accuracy of 94.12% and a negative predictive value (NPV) of 100% and a positive predictive value (PPV) of 91.67%.

CONCLUSIONS

ddPCR analysis of selected lncRNAs in FNA biopsies appears a suitable molecular tool with the potential of improving diagnostic accuracy.

Stimulating TSH receptor autoantibodies immunoassay: analytical evaluation and clinical performance in Graves’ disease

Background

Thyroid-stimulating hormone (TSH) receptor (TSHR) autoantibodies (TRAbs) are a heterogeneous group of antibodies (Abs) with different functionalities. Among all TRAbs, only the stimulating ones (S-TRAbs) are considered as the pathogenetic marker of Graves’ disease (GD). To date, the methods available for TRAbs testing are based on immunoassays (IMAs) which detect total serum TRAbs or bioassays which are not suitable in clinical practice, even though they discern Abs functionality. The aim of our work was to evaluate the analytical and clinical performance of a very recent IMA (Immulite TSI method), supposed to test only the serum concentration of S-TRAbs, in comparison with a current method for total TRAbs (Roche/Elecsys IMA).

Methods

We evaluated serum samples of 145 subjects: 46 with untreated (GD), 36 with chronic autoimmune thyroiditis, 3 with atrophic thyroiditis, 10 with multinodular non-toxic goiter and 50 healthy subjects.

Results

The method showed an optimal analytical sensitivity and high precision levels (LoB: 0.04 UI/L, LoD:0.07 UI/L, LoQ:0.14 UI/L, intra-assay CV: 4.2–5.9%, inter-assay: 4.5–7.2%). By receiver operating characteristics curve analysis, we obtained a value of 0.57 (sensitivity: 98.0%, specificity: 99.9%) as the best cut-off to distinguish GD, apart from four cases. Passing Bablok regression and Bland Altman analysis pointed out a good correlation and agreement with Roche method (R2 = 0.98, slope = 1.03, bias = −2.70).

Conclusions

The new method presents very promising analytical characteristics and could be adopted in clinical practice for GD diagnosis. Moreover, the test allows to accurately detect very low values of analyte with a further clinical utility in detecting earlier possible relapses.

Painful Hashimoto's thyroiditis: myth or reality?

Neck pain is a common complain, being in most cases due to non-thyroidal causes. However, a minority of patients suffer from painful thyroid diseases. Among them, sub-acute thyroiditis (SAT) is the most frequent one. Rare thyroid-related causes of neck pain include hemorrhage within a thyroid nodule as well as Riedel's thyroiditis and suppurative thyroiditis. In the last 30 years, a few cases of a painful variant of Hashimoto's thyroiditis (HT) have been described. Biochemical, ultrasound, and histologic features were clearly suggestive for HT in all of the published cases and definitely ruled out the diagnosis of SAT. While sound descriptions of painful HT are present in the literature, it is important to emphasize that only 20 cases were reported from the year 2000 until now. The condition, however, is clinically relevant because neck pain was reported to be refractory both to steroids and to other analgesic drugs, being thyroidectomy the only effective treatment for pain relief in these patients. This short review analyzes currently available data supporting a role for HT as a rare cause of neck pain.

[Preoperative and postoperative management of adrenal masses]

The surgical approach of adrenal masses requires a careful preoperative and postoperative management. In order to avoid iatrogenic hypocortisolism, Cushing patients have to be treated, before adrenal surgery and then every eight hours, with hydrocortisone 100 mg iv. The therapy should be gradually reduced to 10-20 mg/die by mouth for six-twelve months. In primary hyperaldosteronism the target of medical treatment is to control blood pressure and serum potassium values as well as to normalize the circulating aldosterone levels or to obtain mineralocorticoid receptor blockade. Epleronone and spironolactone are the most common used drugs. Spironolactone has long been the drug of choice while epleronone represents a newer more expensive alternative with fewer side effects. Postoperative management generally does not require steroid replacement therapy. The management of pheochromocytoma requires a careful medical preparation for surgery: in fact, the surgical removal of a pheochromocytoma is a high-risk procedure and an experienced surgeon/anesthesiologist team is required. The preoperative medical therapy is aimed at controlling hypertension (including preventing a hypertensive crisis during surgery) and at avoiding cardiac arrhythmia. The most common used drugs are alpha-adrenergic blockade: phenoxybenzamine is an irreversible, long-acting, nonspecific alpha-adrenergic blocking agent. Doxazosine is a selective alpha1-adrenergic blocking agent with a more favorable side-effect profile, being less related to postoperative hypotension. Postsurgical management is aimed at expanding plasma volume: a copious hydration is required while the use of dopamine in hemodynamin support is not effective because of the preoperative use of alpha-blocking agents.