Association of thyroid autoimmunity and the response to recombinant human growth hormone in Turner syndrome.

OBJECTIVES: Short stature and thyroid autoimmunity are common comorbidities in Turner syndrome (TS). Recombinant human growth hormone (rhGH) significantly improves height growth in TS individuals. This study aims to investigate the association of thyroid autoimmunity and the response to rhGH treatment in TS patients. METHODS: Medical records of 494 patients with TS were reviewed. Among 126 patients who regularly tested for thyroid autoantibodies, 108 patients had received rhGH treatment. Clinical characteristics, including karyotype and the presence of autoimmune thyroid diseases, as well as rhGH treatment records were analyzed. Height velocity (HV) of patients with or without thyroid autoimmunity was compared to assess the response to rhGH treatment. For patients who developed thyroid autoantibodies during rhGH treatment, HV before and after antibody presence were compared. RESULTS: 45XO monosomy presented in 36% (176/496) of patients. 42.1% of patients (53/126) had elevated circulating anti-thyroid peroxidase antibody and anti-thyroglobulin antibody. In 108 patients who received rhGH treatment, HVs were significantly correlated to age, height, weight and BMI at the initiation of treatment. For patients who developed thyroid autoantibodies during rhGH treatment, HVs after thyroid autoantibody presence significantly decreased compared with HVs before thyroid autoantibody detection (n=44, p=0.0017). CONCLUSIONS: Our data suggested that in TS patients who developed thyroid autoantibodies during rhGH treatment, the response to rhGH is negatively associated with the development of thyroid autoimmunity.

Immunological Profile and Autoimmunity in Turner Syndrome.

Turner syndrome (TS), characterized by the partial or complete absence of an X-chromosome, provides a unique insight into the role of the X-chromosome and the immune system. While women have a 10-fold higher incidence of autoimmune disease (AD) compared with men, the risk in women with TS is thought to be further doubled. TS is associated with a propensity for a wide variety of ADs that increase in incidence across the life span. Isochromosome Xq as well as isolated Xp deletion karyotypes may predispose to higher rates of AD in TS suggesting the impact of X-chromosome gene dosage. It is likely, however, that epigenetic changes across the genome and the hormonal milieu may also have a profound impact on the immune profile in TS. This review explores the immune phenotype and the spectrum of ADs in TS. Genotype-phenotype correlations are presented with a brief overview of the genetic and hormonal underpinnings.

Vitamin D receptor (VDR) gene polymorphisms and expression profile influence upon the immunological imbalance in Turner syndrome.

PURPOSE: Turner syndrome (TS) patients display considerable immune misregulation, and it is hypothesized that Vitamin D (VTD) activity may fluctuate according to Vitamin D receptor (VDR) polymorphisms and/or expression profile. To uncover a possible relationship between VDR genotype and clinical conditions in TS patients, we investigated two functional VDR variants (Cdx-2 and FokI) for allele and genotype frequencies, as well as expression profile in TS individuals versus healthy controls (HC). METHODS: We performed a genetic association study including 100 TS patients and 116 HC. Genotyping for VDR Cdx-2 G > A (rs11568820) and FokI C > T (rs2228570) was performed using Taqman Genotyping Assays. VDR gene expression was also evaluated in 15 TS and 15 HC, using fluorogenic probes by qPCR. Statistical analyses were performed using nonparametric Mann-Whitney test, with a 5% significance level (p < 0.05) to uncover differences between groups. In addition, we investigated whether shifted VDR mRNA levels were associated with Cdx-2 and FokI variants in TS patients. RESULTS: We detected a significantly higher frequency of T allele (p = 0.006) as well as T/T genotype (p = 0.01) for FokI in TS patients when compared to HC. When assessing VDR expression, we identified a downregulation in TS woman (- 2.84 FC) versus HC (p < 0.001). Furthermore, C/T (11.24 FC; p = 0.01) and T/T (9.20 FC; p = 0.01) FokI genotypes were upregulated when compared to C/C reference genotype. CONCLUSION: TS patients show different distribution of FokI polymorphism. Downregulation of VDR gene expression may contribute to immunological imbalance in TS.

21-hydroxylase autoantibodies are more prevalent in Turner syndrome but without an association to the autoimmune polyendocrine syndrome type I.

Turner syndrome (TS) is associated with an increased frequency of autoimmunity. Frequently observed autoimmune diseases in TS are also seen in the autoimmune polyendocrine syndrome type I (APS I), of which Addison disease is a key component. An overlapping antibody profile between TS and APS I could be considered. The aim of this work was to study women with TS regarding 21-hydroxylase (21-OH) antibodies and interferon omega (IFN-ω) antibodies, a highly specific marker for APS I, to determine if there are immunological overlaps between TS and APS I. Blood samples from 141 TS were assayed for 21-OH antibodies and IFN-ω antibodies using in-vitro-transcribed and translated autoantigen. Indices with a cut-off point of 57 and 200 for 21-OH antibody and IFN-ω antibody were used as reference. The median age of TS was 31·6 years (range = 11·2-62·2). Positive indices of 21-OH antibodies were present in six TS (4%), with a mean of 144·8 (range = 60-535). None had apparent adrenal insufficiency. There was no age difference comparing 21-OH antibody-positive TS (median age = 33·9 years, range = 17·7-44·7) and 21-OH antibody-negative TS (median age = 31·6 years, range = 11·2-62·2) (P = 0·8). No TS was positive for IFN-ω antibodies (mean = 42·4, range = -435-191). No overlapping autoimmune profile between TS and APS I was found. Autoimmunity against 21-OH among TS patients was more prevalent than previously identified, suggesting an increased risk of adrenal failure in TS. However, whether adrenal impairment will develop remains unknown.

Atypical phenotypic aspects of autoimmune thyroid disorders in young patients with Turner syndrome.

Aim of this commentary is to analyze the current views about the phenotypic features of Hashimoto's thyroiditis (HT) and Graves' disease (GD) in Turner syndrome (TS) girls, in terms of epidemiology, clinical and biochemical presentation, long-term course and metamorphic autoimmunity evolution. In TS GD course is not atypical, whereas HT course is characterized by both a mild presenting picture and a severe long-term evolution of thyroid function tests. Furthermore, TS girls seem to have an increased risk of switching over time from HT to GD. On the light of these findings, it may be concluded that TS girls with HT need a careful monitoring of thyroid status over time. CONCLUSIONS: 1) In children the association with TS is able to condition a peculiar phenotypic expression of HT in terms of epidemiology, presentation course and long-term metamorphic autoimmunity; 2) by contrast, children with TS do not exhibit an atypical clinical and biochemical course of GD, but only a significantly higher prevalence of this disease.

Thyroid Autoimmunity in Girls with Turner Syndrome.

Turner syndrome is associated with increased incidence of autoimmune diseases, especially those of the thyroid gland. The aim of this study was to assess the prevalence of thyroid autoimmunity among pediatric patients with Turner syndrome. The study was retrospective and included 41 girls with Turner syndrome aged 6-18 years. Free thyroxine (FT4), thyroid stimulating hormone (TSH), anti-thyroid peroxidase (TPO-Ab) antibodies, anti-thyroglobulin (TG-Ab) antibodies, and karyotype were investigated. The correlation between karyotype and incidence of thyroid autoimmunity was also examined. Eleven patients (26.8%) were positive for TPO-Ab and/or TG-Ab. Three girls from that subgroup were euthyroid, 5 had subclinical hypothyroidism, and 3 were diagnosed with overt hypothyroidism. Out of these 11 patients affected by thyroid autoimmunity, 6 girls had mosaic karyotype with X-isochromosome (n = 4) or with deletions (n = 2), and 5 had the 45,X karyotype. The study findings confirmed a high incidence of thyroid autoimmunity in girls with Turner syndrome, but we failed to observe an association between the incidence of thyroid autoimmunity and karyotype. We conclude that it is important to monitor thyroid function in patients with Turner syndrome because they are prone to develop hypothyroidism.

CD4+ FOXP3+ Regulatory T Cells Exhibit Impaired Ability to Suppress Effector T Cell Proliferation in Patients with Turner Syndrome.

OBJECTIVE: We investigated whether the frequency, phenotype, and suppressive function of CD4+ FOXP3+ regulatory T cells (Tregs) are altered in young TS patients with the 45,X karyotype compared to age-matched controls. DESIGN AND METHODS: Peripheral blood mononuclear cells from young TS patients (n = 24, 17.4-35.9 years) and healthy controls (n = 16) were stained with various Treg markers to characterize their phenotypes. Based on the presence of thyroid autoimmunity, patients were categorized into TS (-) (n = 7) and TS (+) (n = 17). Tregs sorted for CD4+ CD25bright were co-cultured with autologous CD4+ CD25- target cells in the presence of anti-CD3 and -CD28 antibodies to assess their suppressive function. RESULTS: Despite a lower frequency of CD4+ T cells in the TS (-) and TS (+) patients (mean 30.8% and 31.7%, vs. 41.2%; P = 0.003 and P < 0.001, respectively), both groups exhibited a higher frequency of FOXP3+ Tregs among CD4+ T cells compared with controls (means 1.99% and 2.05%, vs. 1.33%; P = 0.029 and P = 0.004, respectively). There were no differences in the expression of CTLA-4 and the frequency of Tregs expressing CXCR3+, and CCR4+ CCR6+ among the three groups. However, the ability of Tregs to suppress the in vitro proliferation of autologous CD4+ CD25- T cells was significantly impaired in the TS (-) and TS (+) patients compared to controls (P = 0.003 and P = 0.041). Meanwhile, both the TS (-) and TS (+) groups had lower frequencies of naïve cells (P = 0.001 for both) but higher frequencies of effector memory cells (P = 0.004 and P = 0.002) than did the healthy control group. CONCLUSIONS: The Tregs of the TS patients could not efficiently suppress the proliferation of autologous effector T cells, despite their increased frequency in peripheral CD4+ T cells.

Endocrine autoimmunity in Turner syndrome.

BACKGROUND: Turner syndrome is caused by numeric and structural abnormalities of the X chromosome. An increased frequency of autoimmunity as well as an elevated incidence of autoantibodies was observed in Turner patients. The aim of this study was to conduct a retrospective analysis of the incidence of autoimmunity in 66 Italian patients affected by Turner syndrome. METHODS: Sixty-six unselected and consecutive Italian Turner patients were recruited. The association between age, karyotype and the presence of clinical/pre-clinical autoimmune disorders and of autoantibodies was examined. RESULTS: Out of the 66 Turner patients, 26 had thyroid autoimmune disorders (39.4%), 14 patients had Hashimoto's thyroiditis with clinical or subclinical hypothyroidism (21.2%) and 12 patients had circulating anti-thyroid antibodies, echographic pattern of diffuse hypoechogenicity and normal thyroid hormone levels (18.2%). None were affected by Graves' disease. We analyzed the overall incidence of thyroid autoimmunity within the 3 different age groups 0-9.9, 10-19.9 and 20-29.9 years. No statistically significant difference was observed in the incidence of thyroid autoimmunity within the age-groups (χ2-test p > 0.05).Out of the 66 patients, 31 patients had the 45,X karyotype; within this first group 14 out of 31 patients were affected by autoimmune thyroid disease. A second group of 29 patients included 19 patients with mosaicism, 5 patients with deletions and 5 patients with ring chromosome; out of these 29 patients 7 were affected by autoimmune thyroid disease. A third group included 6 patients with X isochromosome; 5 out of 6 were affected by autoimmune thyroid disease. A statistically significant difference in the frequency of thyroid autoimmunity within the different karyotype groups was observed (χ2-test p = 0.0173).When comparing the X isochromosome group with the pooled group of other karyotypes, of note, the frequency of thyroid autoimmunity was statistically higher in the X isochromosome group (Fisher exact test p = 0.0315). CONCLUSIONS: Our data confirm a high frequency of thyroid autoimmunity in Italian Turner patients. Patients with X isochromosome are more prone to develop thyroid autoimmunity. Further, an early assay of autoantibodies and monitoring thyroid hormones is fundamental for detecting hypothyroidism earlier and start adequate replacement therapy.

Prevalence of multiple forms of autoimmunity in Egyptian patients with Turner syndrome: relation to karyotype.

Our study aimed to investigate: the prevalence of autoantibodies related to organ-specific disease; the prevalence of some autoimmune diseases (AID) in Egyptian Turner syndrome (TS) patients; and the association of autoimmunity with patients' karyotypes. Eighty TS patients were subjected to history, auxological assessment and measurement of antithyroid peroxidase antibody (ATPOAb), antithyroglobulin antibody (ATGAb), anti-tissue transglutaminase IgA antibodies (ATTIgAAb), anti-glutamic acid decarboxylase-65 antibodies (GAD-65-Ab) and anti-adrenal cortex antibodies (AACAb). Of the 80 TS patients, 54 (67.5%) were seropositive for one or more autoantibodies. Thirty-five percent were positive for ATPOAb, 15% for ATGAb, 12.5% for ATTIgAAb, 3.75% for Anti-GAD-65Ab and 1.25% for AACAb. There was a non-significant association between the 45,X karyotype and overall prevalence of autoantibodies (p=0.20), while IsoXq was associated with increased prevalence of ATPOAb (p<0.01), ATGAb (p=0.01) and anti-GAD-65Ab (p=0.02). Thus, female TS patients face a high prevalence of autoimmunity and associated AID.

Anti-natrium/iodide symporter antibodies and other anti-thyroid antibodies in children with Turner's syndrome.

Antibodies against the Na/I symporter (anti-NIS ab) have been found in adult patients with autoimmune thyroid diseases. As easily available for the immune system, NIS can play a role in the initial stage of autoimmune thyroid diseases. Children with Turner's syndrome (TS) being at high risk of autoimmune thyroid disease development seem a valuable group for the investigation of the early autoimmune process. The aim of the study was to investigate the presence of anti-NIS ab and its potential clinical significance in TS children. Fifty four girls with TS were examined (age 11.9 ± 2.46 years), and 23 healthy girls with normal thyroid function, free of autoimmune diseases. Anti-NIS antibodies were measured by the in-house ELISA method and the Western blotting. Sera considered positive for anti-NIS ab were used for the iodide uptake bioassay using COS7 cells stably transfected with hNIS. In all patients the thyroid function, antithyroid antibodies presence and thyroid ultrasonography were evaluated. In 20% of the patients a subclinical hypothyroidism was diagnosed and 70.4% had antithyroid antibodies (anti-TPO - 64.8% and Anti-Tg - 24%). Anti-NISab were present in 14.8% girls with TS and in none of the control group. Their presence was unrelated to other antithyroid antibodies titre or patients' age. A positive correlation between the anti-NIS ab presence and the hypothyroidism was found (p < 0.04). Anti-NIS ab-positive sera did not suppress iodine uptake. In conclusion, anti-NIS antibodies were present in 14.8% of children with TS and they were related to the presence of hypothyroidism.

Diabetes mellitus in children and adolescents with genetic syndromes.

BACKGROUND: Several genetic syndromes are associated with diabetes mellitus (DM). This study aimed to analyse data from the DPV database with regard to frequency, treatment strategies and long-term complications in paediatric DM patients with genetic syndromes, including Turner syndrome (TS), Prader-Willi syndrome (PWS), Friedreich ataxia (FA), Alström syndrome (AS), Klinefelter syndrome (KS), Bardet-Biedl syndrome (BBS), Berardinelli-Seip syndrome (BSS) and Down syndrome (DS). METHODS: Longitudinal data for 43 521 patients with DM onset at age < 20 years were collected from 309 treatment centres in Germany and Austria using the DPV software. Data included anthropometric parameters, type of diabetes, mean age, age at diabetes onset, daily insulin dose, HbA 1c , micro- and macroalbuminuria, retinopathy and dyslipidaemia. Descriptive statistics and standard statistical tests were used for data analysis. RESULTS: In total, 205 DM patients had one of the following syndromes: DS (141 patients), TS (24), PWS (23), FA (5), AS (5), KS (4), BBS (2) and BSS (1). Diabetes-specific antibodies were positive in the majority of patients with DS, TS and FA. CONCLUSION: Despite the well-known association between DM and certain syndromic disorders, the number of affected patients in the German and Austrian paediatric diabetic population is very low. Nevertheless, physicians should be aware of syndromic forms of diabetes. Joint multicentre analyses are needed to draw relevant conclusions.

Autoimmune disorders in women with turner syndrome and women with karyotypically normal primary ovarian insufficiency.

The higher prevalence of autoimmune diseases in women compared to men could be due to effects of ovarian hormones, pregnancy and/or the presence of a second X chromosome. To elucidate the role of these factors, we investigated the prevalence and spectrum of autoimmune diagnoses in women with primary ovarian insufficiency associated with X chromosome monosomy (Turner syndrome, TS, n = 244) and women with karyotypically normal (46,XX) primary ovarian insufficiency (POI, n = 457) in a prospective study, conducted at the National Institutes of Health. We compared the study group prevalence to normative data for the U.S. population of women. Chronic lymphocytic (Hashimoto's) thyroiditis (HT) occurred in 37% of women with TS vs. 15% with POI (P < 0.0001); HT prevalence in both ovarian insufficiency groups significantly exceeded that in U.S. population of women (5.8%). Inflammatory bowel (IBD, 4%) and celiac disease (CD, 2.7%) were significantly increased in TS, but not in POI. No other autoimmune diagnosis, including Graves' disease or Type 1 diabetes appears to be significantly increased in either group. Women with TS had higher pro-inflammatory IL6 and TGF ß1 levels (p < 0.0001 for both), and lower anti-inflammatory IL10 and TGF ß2 levels (p < 0.005 for both) compared to POI and to normal volunteers. Lifetime estrogen exposure and parity were significantly lower in TS compared to POI, which were in turn lower than the general population of women. The finding that lymphocytic thyroiditis is greatly increased in both women with TS and POI suggests that factors associated with ovarian insufficiency per se promote this form of autoimmunity. The absence of a normal second X-chromosome further contributes to increased autoimmunity in TS.

Lymphocyte subpopulations in Chinese women with Turner syndrome.

PURPOSE: Turner syndrome (TS) is associated with deficiency of cellular and humoral immunity. However, the characteristics of lymphocyte subpopulations in Chinese women with TS have not been reported. In this study, the percentage of lymphocyte subpopulations and the mRNA expression of some transcription factors were determined in patients with TS. The effect of the hormone substitution on lymphocyte subpopulations was also analyzed. METHODS: Thirteen Chinese TS women and eight age and sex-matched healthy volunteers were studied. The percentage and mean fluorescence intensity (MFI) of lymphocyte subpopulations including CD3+CD4+, CD3+CD8+, CD19-CD138+, CD4+CD25+FoxP3+ and CD4+CD8-IL17A+ cells were determined by flow cytometry. The mRNA expression of some transcription factors were detected by RT-PCR. RESULTS: Compared to control, the percentage of CD3+CD4+ cells was significantly reduced (p < 0.05), while the percentage of CD19-CD138+, CD4+CD25+FoxP3+ and CD4+CD8-IL17A+ cells was significantly increased in TS patients. No difference was observed in the percentage of CD3+CD8+, CD19+ B cells between TS patients and healthy volunteers, with the similar changes in the mean fluorescence intensity of these cells. The mRNA expression of some transcription factors slightly enhanced in TS patients. Estrogen therapy did not affect the percentage of lymphocyte subpopulations. CONCLUSION: These findings suggested that Turner syndrome might be associated with changes of lymphocyte subpopulations.

Autoimmunity and Turner's syndrome.

Turner Syndrome (TS) is a common genetic disorder, affecting female individuals, resulting from the partial or complete absence of one sex chromosome, and occurring in approximately 50 per 100,000 liveborn girls. TS is associated with reduced adult height and with gonadal dysgenesis, leading to insufficient circulating levels of female sex steroids and to infertility. Morbidity and mortality are increased in TS but average intellectual performance is within the normal range. TS is closely associated to the presence of autoantibodies and autoimmune diseases (AID), especially autoimmune thyroiditis and inflammatory bowel disease. Despite the fact that the strong association between TS and AID is well known and has been widely studied, the underlying immunopathogenic mechanism remains partially unexplained. Recent studies have displayed how TS patients do not show an excess of immunogenic risk markers. This is evocative for a higher responsibility of X-chromosome abnormalities in the development of AID, and particularly of X-genes involved in immune response. For instance, the long arm of the X chromosome hosts a MHC-locus, so the loss of that region may lead to a deficiency in immune regulation. Currently no firm guidelines for diagnosis exist. In conclusion, TS is a condition associated with a number of autoimmune manifestations. Individuals with TS need life-long medical attention. As a consequence of these findings, early diagnosis and regular screening for potential associated autoimmune conditions are essential in the medical follow-up of TS patients.

Thyroid ultrasound in patients with Turner syndrome: influence of clinical and auxological parameters.

OBJECTIVES: To determine thyroid volume and structure by ultrasound (US) in patients with Turner syndrome (TS) compared to healthy controls; to evaluate the frequency and characteristics of autoimmune thyroid disease (ATD) and its association with clinical and auxological parameters. PATIENTS: 73 patients and 93 height-matched healthy female controls in the same age range were included in the study. RESULTS: Thirty-two TS patients (43.8%) presented ATD. They had a larger body mass index (BMI) and presented the 45,X karyotype more frequently than those without. They were older, with a higher prevalence of lymphoedema at birth and pterygium colli without statistical significance. Thyroid volume was 20% larger in the presence of ATD (p=0.037). A dyshomogeneous thyroid structure was observed in all patients with ATD and less frequently in those without (p=0.016). Dyshomogeneity in TS without ATD was also associated with older age (p<0.001), larger BMI (p=0.003) and larger thyroid volume (p=0.006). Six TS patients presented solitary thyroid nodules (5 benign nodules). We observed a significant interaction between diagnosis and height (p=0.035) and age (p=0.047), indicating that both age and height conditioned the observed differences in thyroid volume. CONCLUSIONS: Most TS patients presented ATD with a normal thyroid function or subclinical hypothyroidism, without goiter. Dyshomogeneous thyroid structure was also observed in TS patients without ATD. In TS, the evaluation of thyroid volume according to chronological age does not seem to be efficient because of a link between height and thyroid volume. The prevalence of nodular thyroid disease is similar to that observed in the general population.

Follow-up study of immune defects in patients with dysmorphic disorders.

BACKGROUND: In a previous study, we noted immunologic abnormalities in 46 (54.8%) of 84 individuals with dysmorphic disorders. OBJECTIVE: To reevaluate patients with dysmorphic disorders and immunologic abnormalities 2 to 3 years after an initial study to determine any changes in those abnormalities. METHODS: Information was gathered regarding significant infections during the previous 12 months. Blood samples were drawn for the immunologic tests that were previously performed (IgG, IgA, and IgM level determinations; complete blood cell count; and lymphocyte subset enumeration) and for determination of IgG subclasses and T-cell activation by CD69 expression. RESULTS: In the 21 patients available, 26 (63.4%) of the previously noted 41 low immunologic values were still present. In 5 patients, all previously noted immunologic abnormalities resolved. Of the 17 low values noted in 6 patients with Down syndrome, 12 (70.6%) were still present. Also, the 2 patients with Turner syndrome continued to have low IgA and IgM levels. Two patients had a low IgG4 level. A history of significant clinical infections within the previous 12 months was noted in 10 (58.8%) of 17 patients; 8 (47%) had current immune defects. There was a significantly lower T-cell response to staphylococcal enterotoxin B than in healthy controls. The T-lymphocyte activation response was low in 8 (38.1%) of the 21 patients. CONCLUSIONS: Our study revealed a high rate of immune defects in patients with dysmorphic disorders, both during the initial study and 2 to 3 years later, which may contribute to their increased susceptibility to infections. This association was most obvious in patients with Down syndrome and Turner syndrome. The findings should alert for early immunologic evaluation when such patients have infections.