Giuseppe Chiumello

A 7-year experience with low blood TSH cutoff levels for neonatal screening reveals an unsuspected frequency of congenital hypothyroidism (CH)

Context  The guidelines of the National Academy of Clinical Biochemistry advocated the use of low bloodspot TSH (b‐TSH) threshold for newborn screening of congenital hypothyroidism (CH). The impact generated by the application of this indication is largely unknown.

Clinical and molecular profile of a new series of patients with immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome: Inconsistent correlation between forkhead box protein 3 expression and disease severity

BACKGROUND Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is an autoimmune genetic disorder caused by mutation of the forkhead box protein 3 gene (FOXP3), a key regulator of immune tolerance. OBJECTIVE We sought to provide clinical and molecular indicators that facilitate the understanding and diagnosis of IPEX syndrome. METHODS In 14 unrelated affected male subjects who were given diagnoses of IPEX syndrome based on FOXP3 gene sequencing, we determined whether particular FOXP3 mutations affected FOXP3 protein expression and correlated the molecular and clinical data. RESULTS Molecular analysis of FOXP3 in the 14 subjects revealed 13 missense and splice-site mutations, including 7 novel mutations. Enteropathy, generally associated with endocrinopathy and eczema, was reported in all patients, particularly in those carrying mutations within FOXP3 functional domains or mutations that altered protein expression. However, similar genotypes did not always result in similar phenotypes in terms of disease presentation and severity. In addition, FOXP3 protein expression did not correlate with disease severity. CONCLUSION Severe autoimmune enteropathy, which is often associated with increased IgE levels and eosinophilia, is the most prominent early manifestation of IPEX syndrome. Nevertheless, the disease course is variable and somewhat unpredictable. Therefore genetic analysis of FOXP3 should always be performed to ensure an accurate diagnosis, and FOXP3 protein expression analysis should not be the only diagnostic tool for IPEX syndrome.

Urinary Markers of Bone Turnover in Healthy Children and Adolescents: Age-Related Changes and Effect of Puberty

Abstract. During growth, bones change their dimensions rapidly with the changes involving both formation and resorption processes. Small cross-linked peptides coming from type I collagen molecules are excreted in urine when bone is resorbed. To date, conflicting results have been presented concerning the age- and puberty-related changes of urinary markers. The purpose of the present study was to verify the effect of age, gender, and puberty on the urinary excretion of type I collagen degradation products in healthy children and adolescents. Timed spot urines from 176 children (4–20 years old) and 50 young adults were analyzed. The concentrations of N-telopeptides of type I collagen (NTx), pyridinolines (Pyr), and deoxypyridinolines (Dpyr) were measured, and the results were normalized to creatinine. Age-related changes in cross-links excretion were observed. The levels decreased with age, and a peak of excretion was shown at the beginning of adolescence. Prepubertal levels of all the markers were four- to five-fold higher than in adults, and they decreased towards adult levels in late puberty. Girls had significantly higher levels of all biochemical markers than boys at pubertal stage 2. We also observed a remarkable effect of puberty on the levels of bone degradation products that was independent of age and gender. Our results indicate that bone resorption is high in children relative to that in adults, and that urinary levels of NTx, Pyr, and Dpyr change as a function of age, gender, and puberty.

Evidence for In Vivo Primed and Expanded Autoreactive T Cells as a Specific Feature of Patients with Type 1 Diabetes

Identifying β cell autoantigen-reactive T cells that are involved in the pathogenesis of type 1 diabetes has been troublesome for many laboratories. Disease-relevant autoreactive T cells should be in vivo Ag experienced. The aim of this study was to test this hypothesis and then use this principle as a strategy for identifying diabetes-relevant autoreactive T cells. In this study, a CSFE dilution assay was used to detect glutamic acid decarboxylase 65 (GAD65)- and insulin-responsive T cells and HLA-0201*-GAD65114–122 pentamers were used to detect CD8+ GAD-responsive T cells in memory CD45RO+ and naive CD45RO− cell populations from patients with type 1 diabetes and healthy control subjects. T cell proliferative history was evaluated by flow cytometry telomere length measurement. CD4+ and CD8+ T cells specific for GAD65 and insulin were present in patients with type 1 diabetes and control subjects. Within the naive CD45RO− cells, CD4+ and CD8+ T cell responses were similar between patients and controls. Within the memory CD45RO+ cells, CD4+ T cell responses against whole GAD65 and insulin and HLA-0201*-GAD65114–122 pentamer-positive CD8+ T cells were found in patients with type 1 diabetes, but not in control subjects (p < 0.05 for all). Responding cells from the CD45RO+ T cell population had substantially shorter telomere lengths than responding cells from the CD45RO− cell population. Diabetes-specific autoreactive T cells in the circulation have uniquely undergone sustained in vivo proliferation and differentiation into memory T cells. Prior selection of these cells is possible and is a way to identify diabetes-relevant target Ags and epitopes.

Bone density and bone metabolism are normal after long-term gluten-free diet in young celiac patients

Objectives:Osteoporosis and alterations of bone metabolism are frequent complications of celiac disease. We evaluated the impact of long-term gluten-free diet (GFD) initiated during childhood and adolescence on bone mineralization and bone metabolism.Methods:We studied 30 celiac patients on GFD for ≥5 yr. The mean age at diagnosis was 11.4 ± 5.0 yr, and the mean duration of GFD was 10.7 ± 4.3 yr. Results were compared with those obtained in 240 healthy controls. Bone mineral density (BMD) was measured in the lumbar spine and in the whole skeleton by dual-energy x-ray absorptiometry. Serum levels of bone-specific alkaline phosphatase (BALP) and N-terminal propeptide of type I procollagen (PINP) were measured as bone formation indices, and urine levels of N-telopeptide of type I collagen (NTx) as bone resorption index.Results:BMD measurements of celiac patients (lumbar spine: 1.131 ± 0.121 g/cm2; total body: 1.145 ± 0.184 g/cm2) did not differ from those of control subjects (lumbar spine: 1.131 ± 0.184 g/cm2; total body: 1.159 ± 0.118 g/cm2). The levels of BALP, PINP, and NTx of celiac patients did not differ from those of controls. Patients who started GFD before puberty had BMD and bone metabolism measurements comparable to those of patients who started GFD during puberty.Conclusions:Our data show that long-term dietary treatment ensures normal mineralization and bone turnover.

Bone mineral loss through increased bone turnover in Hiv-infected children treated with highly active antiretroviral therapy

ObjectivesTo evaluate the occurrence and define the aetiology of osteopenia in children receiving highly active antiretroviral therapy (HAART). MethodsBone mineral density (BMD) of total body and lumbar spine (L2–L4) was assessed by dual-energy X-ray absorptiometry in 40 children vertically infected with HIV: 35 taking HAART and five naive to any antiretroviral treatment (untreated). Six HAART-treated children showed clinical evidence of lipodystrophy. N-terminal propeptide of type-I procollagen (PINP), bone-specific alkaline phosphatase (BALP) and N-terminal telopeptide of type I collagen (NTx) were measured. Results were compared with those obtained in 314 healthy controls. Differences between HIV-positive and healthy children and within the HIV-positive group were assessed by multivariate analyses, controlling for confounding variables (age, sex, weight and height). ResultsHAART-treated children showed lower spine BMD values than untreated (P = 0.045) and healthy (P = 0.004) children and lower total body BMD values than untreated (P = 0.012) and healthy (P < 0.0001) children. Spine and total body BMD were similar between untreated and healthy children. Total body BMD was lower (P < 0.005) in HAART-treated children with lipodystrophy than in untreated patients, while children on HAART but without lipodystrophy had intermediate values. BALP, PINP and NTx were similar among untreated and healthy children. HAART-treated children had higher BALP levels than healthy (P = 0.0007) and untreated (P = 0.045) children. PINP values showed the same trend as BALP. HAART-treated children had higher NTx urine levels than healthy (P < 0.0001) and untreated (P = 0.041) children. ConclusionsHAART seems a new risk factor for life-long osteoporosis in children. An increased rate of bone turnover causes BMD decrease. Severity of osteopenia seems to be related to lipodystrophy.

Bone Density in Young Patients with Congenital Adrenal Hyperplasia

One of the major complications of glucocorticoid treatment is bone loss. 21-Hydroxylase deficiency is the most frequent inborn error of steroidogenesis, leading to congenital adrenal hyperplasia (CAH): synthesis of cortisol is impaired and replacement therapy is therefore mandatory. We studied the bone mineral density in a group of patients with congenital adrenal hyperplasia (CAH) on long-term glucocorticoid replacement therapy. We selected 30 Caucasian patients with CAH due to 21-hydroxylase deficiency (mean +/- SD age = 17.45 +/- 2.49 years). 22 patients had the classical CAH form and the remaining 8 had the nonclassical (late-onset) form. The mean duration of therapy was 15.20 +/- 4.04 years. Bone mineral density (BMD) was evaluated with a dual-energy X-ray absorptiometer. BMD was also measured in 73 healthy white volunteers of comparable age (17.35 +/- 2.99 years). BMD values of the spine (sBMD), total body (TBBMD), legs, and arms of CAH patients, adjusted for confounding variables (age, gender, body mass index), did not differ from those of control subjects (p = 0.86; p = 0.17; p = 0.06 and p = 0.26, respectively). sBMD and TBBMD values did not show relationships with the duration of treatment and the dose of corticosteroids. Patients with the classical form of CAH had bone density values comparable with those of patients with the nonclassical form (sBMD: p = 0.33; TBBMD: p = 0.97). Our data show that, despite long-term treatment with glucocorticoids, CAH patients have bone density values comparable with controls.

EPIDEMIC OF BREAST ENLARGEMENT IN AN ITALIAN SCHOOL

An outbreak of breast enlargement in girls and boys attending a school in Milan, first noted in November, 1977, was followed up until the end of 1978. 213 boys aged 3-14 years and 110 girls aged 3-7 years were studied; control children attending five other schools were also examined. In total 1647 boys and 476 girls were examined. Breast enlargement was significantly more common in boys (29.0%) and girls (21.6%) aged 3-5 years, boys (58.0%) aged 6-10, and girls (67.1%) aged 6-7 from the school in Milan, than in age and sex matched children at control schools. Breast enlargement was not pronounced and disappeared within 8 months. Hormonal determinations were within normal limits except for 17 beta-oestradiol which was slightly raised. Although oestrogen contamination was not detected when samples of school meals were tested, an uncontrolled supply of poultry and beef was suspected as being the cause of this outbreak.

Association of IA-2 autoantibodies with HLA DR4 phenotypes in IDDM

SummaryInsulin, glutamate decarboxylase (GAD) and the protein tyrosine phosphatase-like molecule IA-2 are major targets of humoral autoimmunity in insulin-dependent diabetes mellitus (IDDM). These autoantibodies are heterogeneous with respect to age and patient human leukocyte antigen (HLA) phenotype. We have previously demonstrated that GAD and IA-2 antibodies potentially identify different subsets of IDDM patients. The aim of this study was to determine whether GAD and IA-2 autoantibodies were associated with different HLA DR phenotypes. We studied 160 patients with IDDM onset before age 16 years. At disease onset serum was tested for GAD and IA-2 antibodies by immunoprecipitation of in vitro-translated35S-methionine labelled recombinant proteins. IA-2 antibodies were significantly associated with HLA DR4: 67 (86 %) of 78 patients with HLA DR4 vs 31 (38 %) of 82 non-DR4 patients had IA-2 antibodies (pc<0.0001) and IA-2 antibody levels were higher in patients with HLA DR4 (pc<0.0001). In contrast, GAD antibodies were more prevalent (pc<0.05) and antibody levels highest (pc<0.01) in patients with HLA DR3 phenotypes. These data provide further evidence that, in IDDM, production and titre of major autoantibody specificities are associated with HLA class II alleles.

Neonatal transient hypothyroidism: aetiological study

AIMS To define the aetiology of neonatal transient hypothyroidism (NTH) and recommend preventive measures. METHODS Maternal and perinatal clinical data on the use of antiseptics, drugs, and contrast agents containing iodine were collected from 40 subjects. Thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroxine (T4), thyroglobulin (TG), TSH receptor antibodies, thyroid peroxidase antibodies and urinary iodine were measured in random neonatal samples. In the mothers with known or suspected thyroid disorders, TSH, FT4, TSH receptor antibodies and thyroid peroxidase antibodies were also measured. RESULTS The NTH aetiology was identified in 85% of cases. More than 50% of the babies with transient hypothyroidism had been exposed to iodine; maternal transfer of antibodies had occurred in a third of them. CONCLUSIONS It is suggested that the practice of using iodine containing disinfectants should be withdrawn, and chlorhexidine substituted instead; that pregnant women should be advised of the adverse effects of using iodine products; and that thyroid function should be monitored whenever iodine is used.