Analytical performance of free testosterone calculated by direct immunoluminometric method compared with the Vermeulen equation: results from a clinical series.

INTRODUCTION: Testosterone (T) is a hormone that is crucial for primary and secondary sexual development in both males and females. Free testosterone (FT) represents the biologically active form of T, and its measurement is of great importance in clinical practice. While application of either equilibrium dialysis or ultrafiltration is considered to be the gold standard for FT assessment, these methods are expensive and not widely accessible. As an alternative, the Vermeulen formula is a commonly utilized calculated method. METHODS: This clinical study, including 190 consecutive patients, was carried out to compare FT levels obtained through direct immunoluminometric assay and the Vermeulen formula. The comparison was performed using Passing-Bablok and Deming regression as well as the Bland-Altman plot. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were assessed. RESULTS: The calculated method employing the Vermeulen formula was considered the gold standard. Passing-Bablok regression indicated a good agreement between the two methods, with slopes close to 1 for the whole series. Although the Bland-Altman plot demonstrated overall agreement, a potential proportional bias was observed in females. Deming regression confirmed excellent agreement and reliable estimates. Sensitivity and specificity analysis revealed that the direct method had a sensitivity of 75.0% and a specificity of 93.4% in all patients. However, sensitivity improved to 81.0% in males and dropped to 18.2% in females likely due to the low number of true positive cases. CONCLUSION: The direct method exhibited comparable performance to the calculated method, but caution should be exercised when interpreting results, particularly in females. Further studies are necessary to validate its sensitivity and specificity in larger series.

Transient Hypogonadism Is Associated With Heart Rate-Corrected QT Prolongation and Torsades de Pointes Risk During Active Systemic Inflammation in Men.

Background Systemic inflammation and male hypogonadism are 2 increasingly recognized "nonconventional" risk factors for long-QT syndrome and torsades de pointes (TdP). Specifically, inflammatory cytokines prolong, while testosterone shortens the heart rate-corrected QT interval (QTc) via direct electrophysiological effects on cardiomyocytes. Moreover, several studies demonstrated important interplays between inflammation and reduced gonad function in men. We hypothesized that, during inflammatory activation in men, testosterone levels decrease and that this enhances TdP risk by contributing to the overall prolonging effect of inflammation on QTc. Methods and Results We investigated (1) the levels of sex hormones and their relationship with inflammatory markers and QTc in male patients with different types of inflammatory diseases, during active phase and recovery; and (2) the association between inflammatory markers and sex hormones in a cohort of male patients who developed extreme QTc prolongation and TdP, consecutively collected over 10 years. In men with active inflammatory diseases, testosterone levels were significantly reduced, but promptly normalized in association with the decrease in C-reactive protein and interleukin-6 levels. Reduction of testosterone levels, which also inversely correlated with 17-ß estradiol over time, significantly contributed to inflammation-induced QTc prolongation. In men with TdP, both active systemic inflammation and hypogonadism were frequently present, with significant correlations between C-reactive protein, testosterone, and 17-ß estradiol levels; in these patients, increased C-reactive protein and reduced testosterone were associated with a worse short-term outcome of the arrhythmia. Conclusions During systemic inflammatory activation, interleukin-6 elevation is associated with reduced testosterone levels in males, possibly deriving from an enhanced androgen-to-estrogen conversion. While transient, inflammatory hypotestosteronemia is significantly associated with an increased long-QT syndrome/TdP risk in men.

Prevalence of hypophysitis in a cohort of patients with metastatic melanoma and prostate cancer treated with ipilimumab.

OBJECTIVE: Ipilimumab is a human monoclonal antibody directed against cytotoxic T-lymphocyte antigen-4, that has been shown to significantly improve survival in patients with metastatic melanoma. Blocking cytotoxic T-lymphocyte antigen-4 elicits T cell activation, proliferation and anti-tumor response, but can also trigger immune-related adverse events. Among immune-related endocrinopathies, hypophysitis represents the most frequent, with an incidence up to 17% in patients treated with ipilimumab. DESIGN AND METHODS: We report nine cases of ipilimumab-induced hypophysitis in a cohort of 273 patients treated with ipilimumab between 2006 and 2015, as part of clinical trials or after its marketing. Thyroid function tests were scheduled at screening and during follow up (every 21 days) in all patients. Cortisol, adrenocorticotropic hormone, follicle-stimulating hormone, luteinizing hormone, and estradiol (for females) or testosterone (for males), prolactin, growth hormone, insulin-like growth factor 1 were measured only in case of clinical suspicion. RESULTS: The incidence of hypophysitis was 3.3%. The most frequent pituitary failure was adrenocorticotropic hormone and thyroid stimulating hormone secretion with a complete recovery of thyroid stimulating hormone, but not of adrenocorticotropic hormone during follow up. All patients had negative pituitary antibodies. The main symptoms at diagnosis were fatigue and headache. CONCLUSION: Clinicians should be aware about the risk of hypophysitis during treatment with immune check-point inhibitors and the necessity of investigating pituitary function during therapy. Pituitary magnetic resonance imaging does not seem pivotal for a definite diagnosis if not performed at the onset of disease.

Reference range of serum calcitonin in pediatric population.

BACKGROUND: Children belonging to the multiple endocrine neoplasia type 2 (MEN 2) pedigree and carrying germline RET mutations are candidates for prophylactic thyroidectomy, the timing of which is based on the mutation-associated risk and the calcitonin (CT) levels. DESIGN: The aim of this study was to establish the reference range for serum CT in a pediatric population. The study included 2740 subjects (1339 females and 1401 males) ranging in age from 1 day to 16 years and undergoing blood testing for any medical condition not affecting serum CT. RESULTS: Overall, serum CT was undetectable in 61.5% of the samples and detectable in 38.5%. Detectable samples were more frequent in the first 2 years of life. Thereafter, undetectable samples became more frequent, particularly in females. Mean serum CT concentrations were higher in the first year of life (9.81 ± 8.8 pg/mL; range, 2.0-48.9 pg/mL) and the second year of life (4.56 ± 2.64 pg/mL; range, 2.0-14.7 pg/mL). A significant decrease of serum CT levels was observed thereafter (P < .001), and starting from the third year of life serum CT levels were similar to those found in adults. No gender difference was found in any age group. Based on these results, age-specific CT reference ranges are needed in the pediatric population, and especially in the first 2 years of life. CONCLUSIONS: This is the first study defining the reference range for serum CT in the pediatric population and large enough to be statistically meaningful. Our proposal may facilitate the process of decision making when dealing with gene carriers of MEN 2.

IFNγ-Inducible Chemokines Decrease upon Selenomethionine Supplementation in Women with Euthyroid Autoimmune Thyroiditis: Comparison between Two Doses of Selenomethionine (80 or 160 µg) versus Placebo.

BACKGROUND: Several studies have suggested that selenium may influence the natural history of autoimmune thyroiditis (AIT). Recently, IFNγ-inducible chemokines (CXCL-9, -10 and -11) were shown to be elevated in AIT patients. OBJECTIVE: This prospective, randomized, controlled study was conducted to evaluate the effect of two doses of selenomethionine (Semet; 80 or 160 µg/day) versus placebo in euthyroid women with AIT, in terms of reduction of anti-thyroid antibodies, CXCL-9, -10 and -11 and improvement of thyroid echogenicity, over 12 months. PATIENTS AND METHODS: Sixty patients, aged 21-65 years, were equally randomized into 3 groups: placebo, 80 µg/day of Semet (80-Semet) or 160 µg/day of Semet (160-Semet). RESULTS: Anti-thyroperoxidase antibody (TPOAb) levels remained unaffected by Semet supplementation; anti-thyroglobulin antibody levels showed a significant reduction in the 160-Semet and the placebo group at 12 months. No significant change in thyroid echogenicity, thyroid volume and quality of life was observed within and between the groups. Subclinical hypothyroidism was diagnosed in 2 patients of the placebo group versus 1 patient in each Semet group. Serum CXCL-9 and -10 were significantly reduced in both Semet groups at 6 and 12 months, while they remained unchanged or increased in the placebo group. CXCL-11, TNFα and IFNγ showed a transient decrease at 6 months in both Semet groups but returned nearly to the basal levels at 12 months. CONCLUSIONS: Semet supplementation had no positive effect on thyroid echogenicity or TPOAb in our patients. However, we observed a Semet-dependent downregulation of the IFNγ-inducible chemokines, especially CXCL-9 and -10, which may serve as helpful biomarkers in future selenium supplementation trials.

Glucagon and insulin cord blood levels in very preterm, late preterm and full-term infants.

BACKGROUND: The cause of hyperglycemia, a frequent disorder of glucose homeostasis in very preterm infants, is still unknown. OBJECTIVES: Determine the glucagon and insulin plasma levels at birth in healthy, appropriate for gestational age (AGA) infants born by elective cesarean section (ECS), at different gestational age. METHODS: Glucagon, insulin and the homeostasis model of assessment-insulin resistance (HOMA-IR) index were measured in cord blood in 52 AGA infants divided into three groups: ≤30 weeks, very preterm (VP, n=16); 35-37 weeks, late preterm (LP, n=18); ≥38 weeks, full term (FT, n=18). RESULTS: In all enrolled infants, Apgar score at 5 min after birth was 7 to 9. In VP infants, glucagon levels were higher than those in LP (533±116 vs. 211±28 pg/mL) (p<0.001) and FT infants (533±116 vs. 226±20 pg/mL) (p<0.001). Insulin levels were higher in VP than in LP (8.61±2.48 vs. 3.98±0.94 mU/L) (p<0.001) and FT infants (8.61±2.48 vs. 4.56±1.2 mU/L) (p<0.001). HOMA-IR index was higher in VP than in LP and FT infants (30.6±10.2 vs. 11.9±3.04 and 13.5±1.6, respectively) (p<0.001). CONCLUSION: We concluded that very low gestational age is associated with high glucagon plasma levels and insulin-resistance, which could explain hyperglycemia in the very preterm infants.

Prevalence of parietal cell antibodies in a large cohort of patients with autoimmune thyroiditis.

BACKGROUND: Autoimmune thyroiditis (AIT) may be associated with other organ-specific autoimmune disorders, including autoimmune gastritis, but the prevalence of this association is not entirely quantified. The aim of this study was to investigate the prevalence of parietal cell antibodies (PCA) in a large cohort of consecutive patients with AIT. METHODS: We retrospectively studied 2016 consecutive women and 258 men with AIT seen at our referral center in the period from 2004 to 2008. All patients were screened for the presence of PCA in the serum. RESULTS: The prevalence of serum PCA in female patients was 29.7% and progressively increased from 13% in the first-second decade of life to peak at 42% in the ninth decade. During follow up, 21.1% of the PCA-positive patients converted to PCA-negative status. Mean (±standard deviation) basal PCA levels in this group were significantly lower (32 ± 28 U/mL) compared with those remaining PCA positive (129 ± 200 U/mL). A similar prevalence (29.8%) with a similar age-dependency was found in male patients. CONCLUSIONS: In conclusion, our study demonstrates a high, age-dependent prevalence of PCA in an unselected large population of patients with AIT.

Serum ghrelin as a marker of atrophic body gastritis in patients with parietal cell antibodies.

AIM: Autoimmune gastritis is frequently associated with autoimmune thyroiditis and other organ-specific autoimmune diseases, and may lead to atrophic body gastritis (ABG). We studied the diagnostic use of the measurement of serum ghrelin compared with other markers of gastric damage in predicting the presence of ABG in patients with autoimmune gastritis. METHODS: We studied 233 patients with autoimmune gastritis and 211 control subjects. All patients and control subjects were screened for circulating parietal cell antibodies (PCAs) and were tested for serum ghrelin, gastrin, pepsinogen I and II, and anti-Helicobacter pylori antibody levels. A total of 52 patients and 28 control subjects underwent a gastric endoscopy. RESULTS: In PCA/positive patients, mean (+/-sd) serum ghrelin levels were significantly lower (238 +/- 107 pmol/liter), and mean (+/-sd) serum gastrin levels were significantly higher (81.2 +/- 128.3 ng/ml), with respect to PCA/negative patients (282 +/- 104 pmol/liter and 20.7 +/- 13.3 ng/ml, respectively; P < 0.0001). Serum ghrelin and gastrin levels were inversely correlated (P = 0.004). A total of 40 patients had ABG documented by the gastric biopsy (90% in PCA/positive patients and 10% in PCA/negative patients). The receiver operating characteristic curve analysis revealed that a cutoff value for serum ghrelin of 188 pmol/liter was associated with the highest sensitivity and specificity (97.3 and 100%, respectively) in detecting gastric atrophy and was superior to gastrin (P = 0.012), PCA (P = 0.002), and the pepsinogen I/II ratio (P = 0.016) measurements. CONCLUSIONS: Our study demonstrates that ghrelin secretion is negatively affected by autoimmune gastritis, and its serum level represents the most sensitive and specific noninvasive marker for selecting patients at high risk for ABG.