Effect of initial levothyroxine dose on neurodevelopmental and growth outcomes in children with congenital hypothyroidism

OBJECTIVES

We designed a multicentre open prospective randomized trial to evaluate the risk-benefit profile of two different initial treatment schemes with levothyroxine (L-T4), 10-12.5 μg/kg/day vs 12.6-15 μg/kg/day, on growth and neurodevelopmental outcomes in children with congenital hypothyroidism (CH) detected by neonatal screening to identify the best range dose to achieve optimal neurocognitive development.

DESIGN PATIENTS AND METHODS

Children detected by neonatal screening were randomly assigned to receive an initial L-T4 dose of 10-12.5 μg/kg/day (Low) or 12.6-15 μg/kg/day (High). All patients underwent periodical clinical examination with measurement of growth parameters and measurement of TSH and FT4. Neurocognitive development was evaluated at the age of 24 months using Griffiths Mental Development Scales (GMDS) and cognitive and behavioral assessment was performed at 48 months of age using Wechsler Preschool and Primary scale of Intelligence (WIPPSI-III). The study was registered with clinicaltrials.gov (NCT05371262).

RESULTS

Treatment schemes below or above 12.5 μg/kg/day were both associated with rapid normalization of TSH and thyroid hormone levels in most patients with no differences in the risk of over- and under-treatment episodes in the first months of life. Growth parameters were normal and comparable between the two groups. Developmental quotients at 24 months of age were normal in both groups (Low 100.6 ± 15.5 vs High 96.9 ± 16.6). Likewise, at 4 years of age IQ and subtest scores were comparable between patients from Low and High (Total IQ 104.2 ± 11.4 vs 101.0 ± 20.3, Verbal IQ 103.9 ± 11.5 vs 98.7 ± 15.1, Performance IQ 105.3 ± 10.4 vs 100.3 ± 19.8). 6/45 CH patients (13.3%) showed a total IQ below 85 (73.7 ± 5.9) regardless of age at diagnosis, L-T4 starting dose, time of FT4 and TSH normalization and episodes of over and undertreatment. Worse socioeconomic status and delayed bone age at diagnosis were the only predictors of an increased risk of having suboptimal IQ at 24 and IQ at 48 months.

CONCLUSIONS

Our results indicate that initial treatment with L-T4, 10-12.5 μg/kg/day vs 12.6-15 μg/kg/day, are both associated with normal growth and neurodevelopmental outcomes in children with CH detected by neonatal screening. Further studies with a long-term follow-up on a larger number of patients are needed to confirm these results.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT05371262?term=NCT05371262&draw=2&rank=1 identifer NCT05371262.

"Block-and-replace" treatment in Graves' disease: experience in a cohort of pediatric patients

PURPOSE

The "block-and-replace" (BR) method involves the use of a high dose of antithyroid drugs (ATD) with levothyroxine (L-T4). Its use in the management of Graves' disease (GD) is still debated mainly because the frequency of side effects of ATD is dose dependent. We retrospectively studied the effect of medium dose of ATD with L-T4 versus monotherapy with ATD in pediatric patients with unstable GD.

METHODS

28 pediatric patients with GD with unstable response to ATD were treated with L-T4 and medium dose of ATD. We compared the rate of euthyroidism, hypothyroidism and hyperthyroidism episodes observed during treatment with methimazole alone with those observed during the BR approach. We evaluated the occurrence of side effects and the rate of remission in patients treated with ATD + L-T4 therapy and the efficacy of combination therapy to postpone a definitive treatment (radioiodine and thyroidectomy).

RESULTS

Patients showed a better control of thyroid function during the BR therapy, presenting fewer episodes of hyperthyroidism and hypothyroidism. No serious side effects during the BR approach were observed. Only one patient went into remission with the ATD + L-T4 therapy. Fifteen patients required a definitive therapy (4 radioiodine, 11 thyroidectomy). The use of BR method has delayed radioiodine treatment for 4.9 years and surgery for 2.9 years.

CONCLUSIONS

The BR method does not increase the remission rates. It may be useful to combine L-T4 with a medium dose of methimazole when GD is difficult to manage with methimazole alone. It may represent a therapeutic option to postpone definitive treatments to a suitable age.

Congenital factor XI and factor VII deficiencies assure an apparent opposite protection against arterial or venous thrombosis: An intriguing observation

OBJECTIVE

To investigate the prevalence and type of thrombotic events reported in patients with congenital factor XI (FXI) or factor VII (FVII) deficiency.

PATIENTS AND METHODS

Data on all patients with congenital FXI or FVII deficiency and a thrombotic event were gathered by means of a time unlimited PubMed search carried out in June 2014 and in February 2015. Appropriate keywords including the medical subject headings were used in both instances. Side tables were also consulted and cross-checking of the references was carried out to avoid omissions. The thrombosis event had to be proven by objective methods.

RESULTS

Forty-three patients with FXI deficiency had arterial thrombosis and only eight had venous thrombosis. On the contrary, only five patients with FVII deficiency had arterial thrombosis whereas 31 patients had venous thrombosis. The arterial/venous ratios were 5.37 and 0.17 for FXI or FVII, respectively.

CONCLUSIONS

Arterial thrombosis is frequent in FXI deficiency whereas venous thrombosis is rare. The reverse is true for FVII deficiency. The significance of these findings is discussed especially in view of the recent use of synthetic anti-FXI compounds in the prophylaxis of post-orthopedic surgery of venous thrombosis complications.

Congenital hypothyroidism treatment in infants: a comparative study between liquid and tablet formulations of levothyroxine

AIMS

To compare the effects of liquid and tablet formulations of levothyroxine (L-T4) in 78 newborns with congenital hypothyroidism (CH).

METHODS

39 patients received liquid L-T4 (group A) and 39 patients received tablets (group B). Thyroid-stimulating hormone (TSH) and free thyroxine (fT4) were measured and L-T4 dose recorded at onset of therapy and during the first year of treatment. Developmental quotient (DQ) was assessed by Griffiths' mental development scales at 12 months of age.

RESULTS

Gestational age, birth weight, screening TSH, etiology and severity of CH, age at onset of therapy and median initial L-T4 dose were similar in both groups. fT4 concentration normalized before 10 days of treatment in all patients. Normalization of TSH concentration was achieved after 7-10 days of therapy in 87% of group A patients and in 82% of group B patients. Group A patients had significantly lower TSH values compared with those of group B at 7-10 days (p = 0.05) and 6-8 months (p = 0.043) of treatment, despite similar L-T4 dose and fT4 concentration. Mean DQ scores were within normal range in all patients.

CONCLUSION

We confirmed the efficacy and safety of both formulations. The TSH inhibition trend when using liquid L-T4 may be linked to a higher absorption in comparison to the tablets.

Asymptomatic thyrotropin-secreting pituitary macroadenoma in a 13-year-old girl: successful first-line treatment with somatostatin analogs

BACKGROUND

Thyrotropin-secreting pituitary adenomas (TSHomas) are an extremely rare cause of hyperthyroidism. Up to now there are only few cases reported in the pediatric age range. Thefirst therapeutic option is surgical resection, whereas medical treatment with somatostatin analogs has been reported only in cases wherein surgery was unsuccessful.

PATIENT FINDINGS

A 13-year-old girl was referred to our clinic for incidental finding of increased circulating free thyroid hormones in the presence of detectable TSH concentrations. She had no signs/symptoms of thyrotoxicosis. Resistance to thyroid hormone was excluded due to the lack of TSH response after thyrotropin-releasing hormone (TRH) stimulation test. Cerebral magnetic resonance imaging showed the presence of a large pituitary macroadenoma, with intra- and suprasellar extension. We decided to treat this patient with somatostatin analog as a first-line therapy because of high surgery risks due to the tumor dimensions. The response to medical treatment was excellent, with rapid and significant tumor shrinkage. No major side effects were reported. The patient developed central hypothyroidism that was corrected with L-thyroxine therapy.

SUMMARY

We report the first pediatric case of TSHoma treated with somatostatin analog as a first-line therapy. The diagnosis was challenging because of the insidious and asymptomatic presentation of the tumor.

CONCLUSIONS

We conclude that somatostatin analogs should be considered as first choice, bridge-to-surgery treatment in young patients, in order to reduce neurosurgical complications and prevent hypopituitarism during pubertal development.

Surgical management of pediatric Graves' disease: an effective definitive treatment

PURPOSE

The optimal treatment for pediatric Graves' disease (GD) is controversial. Antithyroid drugs are often used initially, but they are associated with a high failure rate. Therefore alternative therapies have become important. In the present study, we analyze our institution's experience regarding the safety and efficacy of thyroid surgery among pediatric patients with GD.

METHODS

This is a retrospective chart review of 27 pediatric patients (age ≤ 18 years) with GD who underwent thyroid surgery between 1991 and 2009 at a single academic Institution. We recorded preoperative, intraoperative, and short-term postoperative data.

RESULTS

All 27 patients were initially treated with thionamides. The high rate of hyperthyroidism relapse after discontinuation of medical treatment, age < 5 years, adverse reaction to medical therapy, severe ophthalmopathy, and patient preference justified the final decision to proceed with surgery as definitive therapy. All patients underwent total thyroidectomy. We had no mortality; surgical complications were rare: 4 (14.8 %) cases of transient hypocalcemia, 1 (3.7 %) of permanent hypocalcemia, 3 (11.1 %) of transient RLN neuropraxia, and 2 (7 %) of keloid scar. No bleeding, permanent RLN palsy or relapse hyperthyroidism were reported.

CONCLUSIONS

Surgical therapy for pediatric GD performed by experienced thyroid surgeons is a safe, definitive and cost-effective treatment.

[The biological levels of chloroform in the general population]

The paper reports the results of determination, via gas chromatography and mass spectrometry, of chloroform in expired air, blood and urine of a group of non-occupationally exposed blood donors. Chloroform concentrations were also measured for each subject in the air of the environment where samples were taken.

[Possible effects of lead on various hormonal metabolic pathways]

After reviewing the principal studies on the interferences of lead on the endocrine system, this paper reports the results of a survey carried out on 30 subjects in which the effects of lead on serum FSH, LH and testosterone and on urinary steroid hormones excretion were examined. Statistically significant differences were not demonstrated between lead exposed subjects and control group for serum LH and testosterone (total and free) and for urinary steroids. A significant increase of FSH has been detected in lead exposed workers even if this increase remains between the "normal limits" of the laboratory which performed the determinations. The results are discussed in the light of the more recent knowledge about the endocrine effects of xenobiotics in general and heavy metals in particular and some interpretations to justify the detected FSH increase are proposed.