Cognitive and White Matter Microstructure Development in Congenital Hypothyroidism and Familial Thyroid Disorders

CONTEXT

Children with congenital hypothyroidism (CH) are at risk for suboptimal neurodevelopment.

OBJECTIVES

To evaluate neurocognitive function and white matter microstructure in children with permanent or transient CH and to correlate these findings with disease severity.

DESIGN, PARTICIPANTS AND METHODS

A retrospective and prospective observational study was conducted in 39 children with permanent or transient CH, and in 39 healthy children. Cognitive function was assessed by Wechsler Intelligence Scale, Fourth Edition, and by other tests; the white matter microstructure was investigated by 3 Tesla magnetic resonance imaging.

RESULTS

Children with permanent CH have lower cognitive scores at a median age of 9.5 years than those with transient CH and controls. An IQ score between 71 and 84 was found in 28.6% of permanent CH and of <70 (P = 0.06) in 10.7%. The Processing Speed Index (PSI; P = 0.004), sustained visual attention (P = 0.02), reading speed (P = 0.0001), written calculations (P = 0.002), and numerical knowledge (P = 0.0001) were significantly lower than controls. Children born to mothers with Hashimoto's thyroiditis have significantly lower IQ values (P = 0.02), Working Memory Index (P = 0.03), and PSI (P = 0.02). Significantly lower IQ and Verbal Comprehension Index values were found in children with a family history of thyroid disorders (P = 0.004 and P = 0.009, respectively). In children with permanent CH, significant correlations between abnormalities in white matter microstructural, clinical, and cognitive measures were documented.

CONCLUSIONS

These findings indicate that children with CH are at risk of neurocognitive impairment and white matter abnormalities despite timely and adequate treatment. The association between offspring cognitive vulnerability and maternal thyroid disorders requires careful consideration.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Mycophenolate mofetil and Sirolimus as second or further line treatment in children with chronic refractory Primitive or Secondary Autoimmune Cytopenias: a single centre experience

The management of refractory autoimmune cytopenias in childhood is challenging due to the lack of established evidence on escalating treatments. The long-term efficacy of immunosuppressive drugs was evaluated in children with refractory autoimmune cytopenias referred to the Haematology Unit of the Gaslini Children's Hospital between 2001 and 2014. Patients were grouped into three categories: autoimmune lymphoproliferative syndrome (ALPS), ALPS-related syndrome (at least one absolute/primary additional criterion for ALPS) and primary autoimmune cytopenia (PAC, cytopenia with no other immunological symptoms/signs). Fifty-eight children (aged 1-16 years) entered the study: 12 were categorized with ALPS, 24 were ALPS-related and 22 had PAC. Five didn't receive treatment. Fifty-three were initially treated with steroids/intravenous immunoglobulin. Fourteen responded, whereas 39 did not. Of these 39 patients, 34 (87%) received mycophenolate mofetil (MMF) as second/further-line treatment and 22 (65%) responded. Within these 34 subjects, ALPS patients responded better (11/11, 100%) than the two other groups pooled together (11/23, 48%; P = 0·002). Sirolimus was given as second/further-line treatment to 16 children, and 12 (75%) responded, including 8 who previously failed MMF therapy. Median follow-up was 3·46 years. MMF and Sirolimus were well-tolerated and enabled partial/complete and sustained remission in most children. These drugs may be successfully and safely used in children with refractory autoimmune cytopenias with or without ALPS/ALPS-related disorders and may represent a valid second/further line option.

Wolfram syndrome: new mutations, different phenotype

Background

Wolfram Syndrome (WS) is an autosomal recessive neurodegenerative disorder characterized by Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy, and Deafness identified by the acronym “DIDMOAD”. The WS gene, WFS1, encodes a transmembrane protein called Wolframin, which recent evidence suggests may serve as a novel endoplasmic reticulum calcium channel in pancreatic β-cells and neurons. WS is a rare disease, with an estimated prevalence of 1/550.000 children, with a carrier frequency of 1/354.

The aim of our study was to determine the genotype of WS patients in order to establish a genotype/phenotype correlation.

Methodology/Principal Findings

We clinically evaluated 9 young patients from 9 unrelated families (6 males, 3 females). Basic criteria for WS clinical diagnosis were coexistence of insulin-treated diabetes mellitus and optic atrophy occurring before 15 years of age. Genetic analysis for WFS1 was performed by direct sequencing.

Molecular sequencing revealed 5 heterozygous compound and 3 homozygous mutations. All of them were located in exon 8, except one in exon 4. In one proband only an heterozygous mutation (A684V) was found. Two new variants c.2663 C>A and c.1381 A>C were detected.

Conclusions/Significance

Our study increases the spectrum of WFS1 mutations with two novel variants. The male patient carrying the compound mutation [c.1060_1062delTTC]+[c.2663 C>A] showed the most severe phenotype: diabetes mellitus, optic atrophy (visual acuity 5/10), deafness with deep auditory bilaterally 8000 Hz, diabetes insipidus associated to reduced volume of posterior pituitary and pons. He died in bed at the age of 13 years. The other patient carrying the compound mutation [c.409_424dup16]+[c.1381 A>C] showed a less severe phenotype (DM, OA).

Proteome profile of peritoneal effluents in children on glucose- or icodextrin-based peritoneal dialysis

BACKGROUND

We compared the proteome profile of peritoneal effluents obtained with icodextrin (Ico) or glucose (Glu) in paediatric patients and defined the oxido-redox status of proteins.

METHODS

Sixteen patients underwent two 14-h daytime dwells performed on subsequent days with 7.5% Ico and 3.86% Glu solutions. Protein composition was analysed by two-dimensional electrophoresis and mass spectrometry; oxidized products were evaluated by cyanine labelling.

RESULTS

Peritoneal transport kinetics of β2-microglobulin and cystatin C was linear for both solutions, but was significantly higher with Ico than with Glu, suggesting a better efficiency for these molecules. There was a linear correlation between total protein removal during Ico and Glu dialysis in the same patient, suggesting that it is a function of peritoneal membrane characteristics. The ratio between proteins removed by Ico and by Glu solutions was higher at low removal rate. Image gel analysis revealed 1064 and 774 spots, respectively, in Ico and Glu solutions; 524 were common, and 314 were higher in Ico than Glu effluents. Analysis of protein oxido-redox status showed a greater amount of oxidized albumin in Ico dialysate that was correlated with lower serum levels.

CONCLUSIONS

Our results indicate a better efficiency of Ico in removing small proteins. Removal of big proteins and their oxidized isoforms reflects potentially opposite effects. The long-term clinical consequences of removing also potentially important molecules are to be defined.