Impact of allogeneic stem cell transplantation on thyroid function.

PURPOSE: Primary hypothyroidism is a main endocrine complication after allogeneic stem cells transplantation (allo-SCT) in children, but in adults data on post-SCT hypothyroidism are limited. The aims of this observational, cross-sectional study were to assess the prevalence of hypothyroidism in adult allo-SCT recipients according to time from transplantation, and to identify risk factors. METHODS: One hundred and eighty-six patients (M 104; F 82; median age 53.4 years) who underwent allo-SCT between January 2010 and December 2017 were enrolled and divided into three groups, according to time from allo-SCT (1-3 years; 3-5 years; > 5 years). Pre-transplant TSH and fT4 levels were available for all patients. After transplantation, TSH, fT4 and anti-thyroperoxidase antibodies (TPO-Ab) were evaluated. RESULTS: After a follow-up of 3.7 years, 34 (18.3%) patients developed hypothyroidism, with higher prevalence in females (p < 0.001) and in patients who received matched unrelated donor grafts (p < 0.05). No difference in prevalence was found at different time points. Patients who developed hypothyroidism showed higher rate of TPO-Ab positivity (p < 0.05) and higher pre-transplant TSH levels (median 2.34 µU/ml) compared to those with preserved thyroid function (median 1.53 µU/ml; p < 0.001). Multivariable analysis identified higher pre-transplant TSH levels as a positive predictor of hypothyroidism (p < 0.005). The ROC curve analysis identified a pre-SCT TSH cutoff of 1.84 µU/ml, which can predict hypothyroidism with sensitivity 74.1% and specificity 67.2%. CONCLUSIONS: About one out of four patients developed hypothyroidism after allo-SCT, with a greater incidence in females. Pre-transplant TSH levels seem to predict the onset of post-SCT hypothyroidism.

Elimination of hydrofluoric acid interference in the determination of antimony by the hydride generation technique.

For the determination of antimony by hydride generation techniques a pretreatment procedure has been developed for the reduction of Sb(V) to Sb(III) in order to remove the effect of hydrofluoric acid which strongly interferes with the reduction of pentavalent antimony to the trivalent state. It is based on the combined action of l-cysteine and boric acid at 80 degrees C. The pretreatment is effective in both nitric and hydrochloric acid media. Quantitative recoveries are obtained in less than 60 min. Under these conditions antimony is reduced to the trivalent state in acid media containing both nitric and hydrochloric acid. The method has been applied to the determination of total antimony in certified reference materials of sediments after pressurized microwave digestion with HNO(3)-HCl-HF. Good agreement is obtained by using both analytical techniques: continuous flow hydride generation atomic fluorescence spectrometry and flow injection electrothermal atomic absorption spectrometry with in-situ trapping of stibine in a graphite atomizer.