Central hypothyroidism following chemotherapy for acute lymphoblastic leukemia

BACKGROUND

It has been suggested that chemotherapy per se might impair the hypothalamus-pituitary-thyroid axis of childhood cancer survivors.

OBJECTIVE

We examined six patients treated for acute lymphoblastic leukemia (ALL) with chemotherapy alone, with suspicious central hypothyroidism (CH).

SUBJECTS AND METHODS

ALL was diagnosed at a mean age of 3.8 years (range 0.3-6 years), the mean follow-up is 6 years (range 6-13 years). Auxological data were recorded, and thyroid function, autoimmunity and ultrasonography (US) were evaluated. Three individuals underwent a thyrotropin-releasing hormone (TRH) test and a magnetic resonance imaging (MRI) scan of the hypothalamic-pituitary region.

RESULTS

All study participants showed negative thyroid autoimmunity, normal thyroid ultrasound, and thyroid-stimulating hormone (TSH) above the normal range; free T4 (fT4) was abnormally low in two patients. After TRH infusion all patients showed TSH increase and slow TSH decline.

CONCLUSIONS

Our study shows that CH could arise at any time after childhood leukemia following only chemotherapy treatment. Although overt hypothyroidism was detected in only two patients, a careful follow-up of thyroid function is also recommended for ALL survivors not treated by irradiation.

Diagnostic features of thyroid nodules in pediatrics

OBJECTIVE

To investigate a cohort of pediatric patients with thyroid nodules, defining histotype frequency and differences between subjects with hyperthyroidism and euthyroidism and benign and malignant nodules.

DESIGN

Retrospective cohort.

SETTING

Consecutive cases from 9 Italian pediatric endocrinology centers for the last 10 years. Patients One hundred twenty pediatric patients with thyroid nodules. Intervention Doppler ultrasonography was performed in 71 subjects; scintiscan, in 56; fine-needle aspiration biopsy in 104; and 63 underwent surgery.

MAIN OUTCOME MEASURES

The differences in clinical, laboratory, and ultrasonographic data between patients with hyperthyroidism and euthyroidism and malignant and benign nodules were evaluated.

RESULTS

One hundred fourteen patients had euthyroidism and 6, hyperthyroidism. The latter had more compressive signs (P=.003), greater nodule diameter (P=.02), intranodular vascularization pattern (P=.01), and increased scintiscan uptake (P<.001). Fine-needle aspiration biopsy disclosed benign lesions in 77 cases, malignant lesions in 19, and "suspicious" lesions in 8. Histologic examination disclosed 1 Hurthle cell and 5 follicular adenomas in patients with hyperthyroidism, whereas in patients with euthyroidism, 33 hyperplasic nodules, 19 carcinomas (14 papillary, 3 follicular, and 2 medullary), 3 follicular and 1 Hurthle cell adenoma, and 1 teratoma were detected. Nine patients had enhanced scintiscan uptake. Among the patients with euthyroidism, malignancies more frequently had palpable lymph nodes (P<.001), compressive signs (P=.004), microcalcifications (P<.001), intranodular vascularization (P=.01), and lymph node alterations (P<.001).

CONCLUSIONS

The diagnosis of pediatric thyroid nodules should be based on a stepwise evaluation that includes clinical, laboratory, and radiographic modalities. While laboratory assessments establish thyroid function, ultrasonographic imaging identifies clinically unapparent nodules and provides detailed nodule characterization for suspected malignant lesions. Scintiscan in patients with hyperthyroidism and fine-needle aspiration biopsy in patients with euthyroidism represent the next logical step.

The SHOX gene: a new indication for GH treatment

Short stature homeobox-containing (SHOX) gene mutations causing haploinsufficiency have been reported in idiopathic short stature, but the real prevalence of this defect in the population with growth failure is debated. Based on current data, the prevalence of SHOXdefect (SHOX-D) has been calculated to have occurred in at least 1 in 2,000 children. This occurrence rate is higher than that of classic GH deficiency or Turner syndrome. In all probability, the real prevalence of SHOX-D will increase in the future with the improvement of the genetic analysis with investigations for point mutations in the enhancer sequences or for deletions in other parts of this region. A selection criterion to individuate the most appropriate candidates eligible for the SHOX region analysis has been suggested based on the evaluation of a disproportional short stature. The efficacy of GH treatment in these patients has recently been demonstrated with results that are similar to those observed in Turner syndrome.

Long-term clinical significance of thyroid autoimmunity in children with celiac disease

OBJECTIVE

To evaluate the long-term outcome of thyroid function and autoimmunity in a large series of children with celiac disease.

STUDY DESIGN

This longitudinal, retrospective study (duration of follow-up, 8.9 +/- 4.0 years) was conducted at the Pediatric Department, University of Bologna, Italy. One hundred thirty-five consecutive patients diagnosed between June 1990 and December 2004 and followed on a gluten-free diet were examined. Inclusion criteria were good dietary compliance and duration of follow-up for at least 3 years.

RESULTS

Of 101 patients who never showed positive antithyroid titers during the follow-up, 86 remained euthyroid; 15 showed high thyroid-stimulating hormone values at diagnosis that normalized in 11 cases after 12 to 18 months of gluten withdrawal. Of 31 patients with persistently positive antibody titers, 23 (74%) remained consistently euthyroid during the follow-up and 8 (26%) had a subclinical hypothyroidism. The prevalence of cases with positive antibodies was similar in children with growth retardation or gastroenterological symptoms at diagnosis and different durations of gluten exposure.

CONCLUSIONS

The presence of antithyroid antibodies in children with celiac disease has a low predictive value for the development of thyroid hypofunction during the indicated surveillance period. Longer follow-up is needed.

Synthesis of picosecond pulses by spectral compression and shaping of femtosecond pulses in engineered quadratic nonlinear media

Narrow-bandwidth picosecond pulses of predetermined spectral and temporal shapes are generated with high efficiency by frequency conversion of femtosecond pulses in lithium tantalate crystals with engineered quasi-phase-matching structures. We give examples of the synthesis of Gaussian and super-Gaussian picosecond pulses and also of a pair of synchronized phase-coherent picosecond pulses with a predetermined carrier-frequency difference.

Thyroid nodules and cancer in children and adolescents affected by autoimmune thyroiditis

OBJECTIVE

To investigate the association between juvenile autoimmune thyroiditis (JAT) and thyroid cancer in pediatric patients.

DESIGN

We conducted a retrospective study among children and adolescents affected by JAT.

SETTINGS

Data from 6 Italian pediatric endocrinology centers were collected.

PARTICIPANTS

Three hundred sixty-five children and adolescents affected by JAT diagnosed at 3.6 to 17.0 years of age.

INTERVENTIONS

All patients underwent clinical examination and thyroid function test every 6 to 12 months and thyroid echography every 12 to 24 months. Fine-needle aspiration biopsy was performed in 39 patients with nodule diameter of 1 cm or larger, as well as in 4 patients with nodule diameter of less than 1 cm and echographic findings suspicious for neoplasm. Twenty-three patients underwent surgery.

MAIN OUTCOME MEASURES

Thyroid function, echographic pattern, nodule diameter, the presence of lymphadenopathy, and cytologic and histologic diagnoses were considered.

RESULTS

Thyroid nodules were found in 115 patients; findings in 11 of these were consistent with papillary carcinoma, with 5 exhibiting lymph node metastasis. The prevalence of male sex among patients with cancer was greater than that among patients with JAT (odds ratio [OR], 2.95; 95% confidence interval [CI], 1.44-6.20). The growth of nodules during levothyroxine sodium therapy (OR, 15.60; 95% CI, 1.87-181.90) and the finding of lymphadenopathy (OR, 5.44; 95% CI, 1.05-30.50) were statistically significantly associated with the presence of cancer, while uninodularity and hypoechogenicity were not.

CONCLUSIONS

The observed prevalences of thyroid nodules and thyroid cancer in our JAT case series were 31.5% and 3.0%, respectively. Papillary carcinoma was the only histotype detected. The finding of lymphadenopathy, a lack of response to levothyroxine therapy, and nodule hypoechogenicity suggested malignancy. Fine-needle aspiration biopsy was reliable in selecting patients for referral to surgery.

Narrow-bandwidth picosecond pulses by spectral compression of femtosecond pulses in second-order nonlinear crystals

We introduce a simple approach for the efficient generation of tunable narrow-bandwidth picosecond pulses synchronized to broadband femtosecond ones. Second harmonic generation in the presence of large group velocity mismatch between the interacting pulses transfers a large fraction of the energy of a broadband fundamental frequency pulse into a narrowband second harmonic one. Using a periodically poled stoichiometric lithium tantalate crystal coupled to an infrared optical parametric amplifier, we generated 200-nJ pulses with spectral width lower than 8.5 cm(-1) and tunability from 720 to 890 nm. Energy scaling and extension of the tuning range are straightforward.

Functional characterization of naturally occurring NR3C2 gene mutations in Italian patients suffering from pseudohypoaldosteronism type 1

OBJECTIVE

The renal form of pseudohypoaldosteronism type 1 (PHA1) is a rare disease caused by mutations in the human mineralocorticoid receptor gene (NR3C2).

DESIGN

Aim of the study was to analyze the NR3C2 gene in three Italian patients with clinical signs of renal PHA1 and to evaluate the distribution of the -2G > C, c.538A > G, and c.722C > T single nucleotide polymorphism (SNP) pattern in the PHA1 patients and in 90 controls of the same ethnic origin.

METHODS

Analysis of the NR3C2 gene sequence and of the polymorphic SNP markers. Functional characterization of the detected novel NR3C2 mutations utilizing aldosterone-binding assays and reporter gene transactivation assays.

RESULTS

One novel nonsense (Y134X) and one novel frameshift (2125delA) mutation were detected. They exhibited no aldosterone binding and no transactivation abilities. No mutation was detected in the third patient. Haploinsufficiency of NR3C2 was ruled out by microsatellite analysis in this patient. The c.722T SNP was detected in 97% of alleles in the Italian population which is significantly different from the general German or US population.

CONCLUSIONS

Molecular analysis of the NR3C2 gene in PHA1 patients is warranted to detect novel mutations in order to clarify the underlying genetic cause, which may extend the insight into relevant functional regions of the hMR protein. The effect the different distribution of the c.722T SNP is not clear to date. Further studies are necessary to provide evidence as to a possible advantage of a less sensitive hMR in southern countries.

Effect on adult height of pubertal growth hormone retesting and withdrawal of therapy in patients with previously diagnosed growth hormone deficiency

CONTEXT

GH replacement therapy in GH-deficient (GHD) patients is usually continued until adult height despite the fact that most of these subjects display a normal secretion when retested at the end of growth. Puberty is the most likely time for normalization of GH secretion.

OBJECTIVES

The objectives of this study are to establish the characteristics and the percentage of the subjects with isolated GHD who normalized secretion at puberty and to compare their statural outcomes with those of the subjects with persistent deficiency treated also after retesting.

DESIGN AND SETTING

This was a prospective, nonrandomized, open-label study conducted in a university research hospital.

PATIENTS AND INTERVENTION

Sixty-nine subjects (40 male, 29 female) with a diagnosis before puberty of isolated GHD by means of arginine and l-dopa tests were reevaluated with the same tests after at least 2 yr of therapy and after puberty onset. If GH peak at retesting was more than 10 microg/liter, therapy was withdrawn.

MAIN OUTCOME MEASURES

Percentage and characteristics of normalized subjects at retesting, outcome of treatment in the subjects treated or untreated to adult height, and factors predictive of growth outcome were measured.

RESULTS

At retesting, 44 subjects (63.7%) confirmed a GH peak less than 10 microg/liter (24 of 40 male and 20 of 29 female). Apart from a less delayed bone age at diagnosis in females, the subjects with confirmed GHD were not different at diagnosis from the other group for height deficit at diagnosis, first year growth response to GH, age and height at puberty onset, height, and IGF-I at retesting. Mean adult height was 165.1 +/- 4.5 cm in the male group treated until adult height vs. 164.0 +/- 3.4 cm in the group who suspended therapy at retesting. Mean adult height was 153.2 +/- 4.1 cm in the female group treated until adult height vs. 152.9 +/- 5.2 cm in the group that suspended therapy at retesting. As regards the parameters expressing the final outcome, the only difference was found in the mean increment adult height-target height sd score in favor of the male group treated until adult height. In both sexes, therapy duration and GH levels at diagnosis and at retesting were unrelated to adult height parameters and to height increments during the period of observation.

CONCLUSIONS

One third of our GHD subjects diagnosed before puberty presented a normal secretion at puberty. The withdrawal of GH therapy in these subjects after retesting was not associated with a catch down growth, and they obtained an adult height similar to those obtained by the GHD subjects treated until adult height. It seems convenient, in subjects with nonsevere GHD, to retest GH secretion at midpuberty and to withdraw treatment for the subjects that are no longer deficient.

Birth length and weight in congenital adrenal hyperplasia according to the different phenotypes

The aims of this study were to: (1) retrospectively investigate the birth length and weight of our patients with congenital adrenal hyperplasia (CAH); (2) compare these parameters with standards for birth length and weight recently assessed in an Italian control population; (3) evaluate whether neonatal auxological data may change depending on the different clinical forms of CAH. Birth length and weight were retrospectively evaluated in 101 children with different clinical forms of CAH and compared with standards for birth length and weight assessed in an Italian control population. In both sexes the average birth length of patients with classical CAH was greater than the mean birth length of the controls, and both length and weight were greater in children with classical CAH than in those with the non-classical form. Among the patients with classical CAH, those with the salt-wasting form were longer but also weighed less than those with the simple-virilizing form.

CONCLUSIONS

(1) fetal length velocity in patients with CAH may be increased only in those infants with classical forms of the syndrome, while it is unaffected in those with the non-classical form; (2) the greater the enzymatic activity impairment, the longer the birth length of newborns with CAH.

Spectral shift of femtosecond pulses in nonlinear quadratic PPSLT Crystals

Spectral blue- and red-shifts in a range of 100 nm are achieved by propagating 40 fs pulses with a 70 nm spectrum centered at 1450 nm in a 25-mm-long periodically poled stoichiometric lithium tantalate crystal. We show experimentally that these shifts, originating from a phase-mismatched second harmonic generation process under conditions of strong group velocity mismatch, can be efficiently controlled by acting on pulse intensity and phase-mismatch.

A new DAX1 gene mutation associated with congenital adrenal hypoplasia and hypogonadotropic hypogonadism

We report on a DAX1 gene investigation in a patient with X-linked adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism (HH) in order to identify mutations causing this disorder and to confirm the clinical diagnosis. The description of the clinical course of the condition with a detailed documentation of longitudinal data is also reported. A male newborn was referred at 45 days of life because of vomiting, dehydration, and weight loss. The diagnosis was primary adrenal insufficiency. The appropriateness of glucocorticoid therapy during the prepubertal period was difficult to judge because of elevated ACTH levels on one hand and progressive retardation of bone age on the other hand. Basal and GnRH stimulated gonadotropin levels remained low during the entire period of examination and exogenous gonadotropin treatment was begun. This had to be interrupted at age 14.6 years because of the occurrence of a 3rd degree anaplastic ependimoma of the left posterior-parietal region, without apparent lepto-meningeal involvement. The molecular analysis of DAX1 gene of the propositus showed deletion of nucleotides AAT in exon 2, resulting in the loss of the Asn430. No alterations were found in the mother and grandmother. This deleted residue lies in one of the helices forming the hydrophobic core of the ligand-binding domain (LBD); thus this mutation may be the cause of the observed phenotype. Further investigations are needed to verify its causal role in AHC associated with HH.

Height as a risk factor for osteosarcoma

Previous investigations have suggested that osteosarcoma may be associated with a taller stature, but the relationship between height and osteosarcoma remains controversial. Height at diagnosis was evaluated in a continuous series of 962 osteosarcoma subjects treated between 1981 and 2001. Patients diagnosed during growth (group 1) were separated from those diagnosed in adulthood (group 2). Height (H) and final height (FH) were expressed as standard deviation scores (SDS), calculated by national reference data. Group 1 subjects were above the 50th centile and their mean H-SDS values (0.31 +/- 1.1) were significantly higher than the mean FH-SDS values (P < 0.0001) of the group 2 subjects, both in males and females. In contrast, the mean FH-SDS (0.01 +/- 1.1) of group 2 did not differ from that of the reference population. The highest incidence of osteosarcoma was at 12.5 years in females, 14.5 years in males. These data confirm previous observations of an association between osteosarcoma development and height, at least in growing individuals. The higher incidence during the pubertal spurt, in the anatomic sites of greater growth and in taller individuals, suggests that growth factors play an important role in the pathogenesis of this bone cancer.

CYP21 genotype, adult height, and pubertal development in 55 patients treated for 21-hydroxylase deficiency

In a retrospective study we evaluated long-term growth, pubertal developmental patterns to final height (FH), and medication in 55 patients (35 females) affected by 21-hydroxylase deficiency. The patients were classified into 3 groups according to predicted mutation severity: group A (11 women and 9 men), homozygous or compound heterozygous for null or In2 splice mutations [residual enzymatic activity (RA), <1%]; group B (11 women and 4 men), homozygous for I172N or R341P or R426H mutations (RA, approximately 2-3%) or compound heterozygous with any of the group A or B mutations; and group C (13 women and 7 men), homozygous for P30L or V281L or P453S mutations (RA, >30%) or compound heterozygous with any of the group A, B, or C mutations. Three patients showed unclassifiable genotypes. FH was similar in the female groups, whereas male patients in group B were shorter than males in groups A and C. Fifty-five percent of patients in group A, 33% in group B, and 40% in group C reached an FH within 0.5 SD of target height. Four of the 7 patients diagnosed via neonatal screening achieved an FH equal to or above the target height. In the entire group, early diagnosis (<1 yr) improved height outcome. Early diagnosed CAH patients who received lower cortisol equivalent doses during the first year of life reached a better FH. Our results underline the importance of mineralocorticoid therapy, as CAH subjects in groups A and B who did not receive this treatment showed reduced FH. Early diagnosis, the use of more physiological cortisol equivalent dosages during the first year of life, and the extension of mineralocorticoid therapy to all classical patients are shown to improve the auxological outcome. Genotypic analysis helped to interpret the height results of our cases and prospectively may represent a useful tool for improving the therapeutic choice and the height outcome.