Barbara Pirali

Raised serum TSH levels in patients with morbid obesity: is it enough to diagnose subclinical hypothyroidism?

OBJECTIVE Morbid obesity (body mass index (BMI)> or =40 kg/m(2)) is associated with thyroid function disturbances, with a high rate of subclinical hypothyroidism (SH) being the most consistently reported. We evaluated the circulating thyroid function parameters in morbid obese patients and related the results to the presence of circulating thyroid antibodies (Thyr-Ab). DESIGN AND METHODS Morbid obese patients were consecutively enrolled (n=350). Two control groups were used: control group (CG)1, healthy normo-weight subjects (n=50); CG2, normo-weight patients with SH (n=56) matched for TSH with the obese patients with SH. Serum levels of free triiodothyronine (FT(3)), free thyroxine (FT(4)), TSH, antithyroglobulin antibodies, and antithyroperoxidase antibodies were measured in all patients. RESULTS i) Compared with CG1, obese patients having thyroid function parameters in the normal range and negative Thyr-Ab showed significantly higher serum TSH and lower free thyroid hormones levels, but a similar FT(4)/FT(3) ratio; ii) SH was recorded in 13.7% obese patients; iii) compared with CG2, obese patients with untreated SH had a significantly lower rate of positive Thyr-Ab (32.1 vs 66.1%; P<0.005); iv) no gender prevalence was observed in SH obese patients with negative Thyr-Ab; and v) the comparison of the untreated SH patients (obese and normo-weight) with CG1 demonstrated that in SH obese subjects, unlike normo-weight SH patients, the FT(3) levels were significantly lower. This resulted in a normal FT(4)/FT(3) ratio in SH obese patients. CONCLUSION Thyroid autoimmunity is not a major cause sustaining the high rate of SH in morbid obese patients. In these patients, the diagnosis of SH itself, as assessed by a raised TSH alone, appears questionable.

Predictive Role of the Immunostaining Pattern of Immunofluorescence and the Titers of Antipituitary Antibodies at Presentation for the Occurrence of Autoimmune Hypopituitarism in Patients with Autoimmune Polyendocrine Syndromes over a Five-Year Follow-Up

CONTEXT Antipituitary antibodies (APA) are frequently present in patients with autoimmune polyendocrine syndrome (APS). DESIGN The aim was to evaluate the predictive value of APA for the occurrence of hypopituitarism. A total of 149 APA-positive and 50 APA-negative patients with APS and normal pituitary function were longitudinally studied for 5 yr. METHODS APA, by indirect immunofluorescence, and anterior pituitary function were assessed yearly in all patients. The risk for developing autoimmune pituitary dysfunction was calculated using survival and multivariate analysis. RESULTS Hypopituitarism occurred in 28 of 149 (18.8%) APA-positive patients but in none of the 50 APA-negative patients. The immunostaining pattern in APA-positive patients involved either isolated pituitary cells [type 1 pattern; n=99 (66.4%)] or all pituitary cells [type 2 pattern; n=50 (33.6%)]. All patients developing pituitary dysfunction throughout the study span had a type 1 pattern. Kaplan-Meier curves for cumulative survival showed a significantly higher rate for developing hypopituitarism in relation to positive APA tests (P<0.005), pattern of immunostaining (P<0.0001), and APA titers (P<0.000001). Cox regression analysis in APA-positive patients with a type 1 pattern demonstrated a significantly (P<0.0001) higher risk for the onset of hypopituitarism in relation to increasing titers of APA. CONCLUSIONS APA measurement by immunofluorescence may help to predict the occurrence of hypopituitarism but only when considering the immunostaining pattern and their titers. Combined evaluation of these parameters allows identifying patients at higher risk for pituitary autoimmune dysfunction, thus requiring a strict pituitary surveillance to disclose a preclinical phase of hypopituitarism and possibly interrupt therapeutically the progression to clinically overt disease.

Interstitial laser photocoagulation for benign thyroid nodules: time to treat large nodules.

Interstitial laser photocoagulation (ILP) is a new therapeutic option for the ablation of non‐functioning and hyper‐functioning benign thyroid nodules. Amelioration of the ablation procedure currently allows treating large nodules. Aim of this study was to evaluate the therapeutic efficacy of ILP, performed according to a modified protocol of ablation, in patients with large functioning and non‐functioning thyroid nodules and to identify the best parameters for predicting successful outcome in hyperthyroid patients.

Serum negative autoimmune thyroiditis displays a milder clinical picture compared with classic Hashimoto's thyroiditis

BACKGROUND Despite high sensitivity of current assays for autoantibodies to thyroperoxidase (TPO) and to thyroglobulin (Tg), some hypothyroid patients still present with negative tests for circulating anti-thyroid Abs. These patients usually referred to as having seronegative autoimmune thyroiditis (seronegative CAT) have not been characterized, and definite proof that their clinical phenotype is similar to that of patients with classic chronic autoimmune thyroiditis (CAT) is lacking. OBJECTIVE To compare the clinical phenotype of seronegative CAT (SN-CAT) and CAT as diagnosed according to a raised serum level of TSH with negative and positive tests for anti-thyroid Abs respectively. METHODS A case-control retrospective study enrolling 55 patients with SN-CAT and 110 patients with CAT was performed. Serum free triiodothyronine (FT3), free thyroxine (FT4), TSH, Tg Abs, and TPO Abs were measured in all patients. RESULTS Patients with SN-CAT displayed significantly lower mean levels of TSH (6.6±3.4 vs 10.2±9.8 μU/ml; P=0.009), higher mean FT4 levels (1.1±0.2 vs 0.9±0.2 ng/dl; P=0.0002), and similar FT3 levels when compared with CAT patients. Mean thyroid volume was significantly greater in patients with CAT when compared with SN-CAT patients (11.2±6.5 vs 8.1±3.7 ml; P=0.001). Logistic regression demonstrated that FT4 (0.123 (0.019-0.775); (P=0.026)) and thyroid volume (1.243 (1.108-1.394); (P=0.0002)) were significantly and independently related to the diagnosis (CAT/SN-CAT). Patients with SN-CAT had a similar prevalence of thyroid nodules and female gender but a lower prevalence of overt hypothyroidism (5.4 vs 20.9%; P=0.012) as opposed to patients with CAT. CONCLUSIONS These results suggest an autoimmune etiology of SN-CAT, which, however, seems to have a milder clinical course when compared with CAT.

A Unique Patient Presenting With Concomitant Klinefelter Syndrome, Alport Syndrome, and Craniopharyngioma

A 31-year-old Caucasian male was referred for panhypopituitarism resulting from a surgically removed craniopharyngioma. The patient had been previously submitted to kidney transplantation for end-stage renal disease from X-linked Alport syndrome (ATS). Subsequent quantitative fluorescent polymerase chain reaction analysis indicated a 47,XXY karyotype consistent with Klinefelter syndrome (KS). The relevance of this unique case stems from several issues: 1) KS was an unexpected finding because of a previous diagnosis of hypogonadotropic hypogonadism resulting from craniopharyngioma; 2) the discovery of a de novo p.G406S substitution causing ATS; and 3) the multifactor origin of severe sexual dysfunction. This is the first description of the co-occurrence of KS, ATS, and craniopharyngioma.

Funzione tiroidea e gravidanza

RiassuntoLa fecondazione dell’oocita e lo sviluppo dell’embrione si accompagnano a profonde modificazioni dell’equilibrio endocrino-metabolico della madre. Questi cambiamenti dipendono in parte dall’attività secretiva ormonale propria dell’unità feto-placentare e, in parte, dalla presenza nei tessuti embrionali e placentari di enzimi e trasportatori capaci di modificare il metabolismo degli ormoni provenienti da altri distretti. La regolazione del sistema endocrino si verifica in larga misura autonomamente nella madre e nel feto, ma i due sistemi si influenzano e comunicano attraverso la placenta e le membrane che modulano il passaggio degli ormoni tra i due compartimenti.