Thyroid complications after hemopoietic stem cell transplantation in children and adolescents.

PURPOSE: To evaluate the prevalence of thyroid dysfunction and its association with possible contributing factors related to diagnosis and treatment in children who received hematopoietic stem cell transplantation (HSCT) in the only national transplant unit in Greece. METHODS: This is an observational, retrospective, single center cohort study that included 194 patients (58.6% boys) who survived for at least 1 year following allogeneic HSCT. Conditioning regimens depended upon diagnosis and protocols active at the time of transplantation. Some patients received irradiation, either central nervous system prophylaxis (n = 20), or total body irradiation (TBI) (n = 8). Thyroid gland evaluation included thyroid-stimulating hormone, free thyroxine, thyroid autoantibodies, and sonogram. Univariate and multivariate logistic models were used to examine the association of the above-mentioned factors with hypothyroidism. RESULTS: The mean age at diagnosis and at bone marrow transplant (BMT) in years was 7.51 ± 0.46 and 7.58 ± 0.36, respectively. The median follow-up time was 4.83 years. Hypothyroidism was detected in 33 cases (17.7%), four of those patients having received TBI. Factors contributing to hypothyroidism as per the multivariate analysis were male sex, [OR: 3.005, 95% CI (1.145-7.890)], irradiation, [OR: 2.876, 95% CI (1.120-7.386)], and years after HSCT [OR: 1.148, 95% CI (1.042-1.266)], while malignancy was identified only in the univariate analysis. The multivariate model presents a good class separation capacity [AUC = 72%, 95% CI (61.4%-82.4%)], Two patients had papillary thyroid cancer, both among children who had received TBI. CONCLUSION: These data highlight the fact that male sex and radiotherapy are two independent factors that lead to increased risk for hypothyroidism. Furthermore, the prevalence of hypothyroidism increases with time post HSCT.

Impact of allele-specific anti-human leukocyte antigen class I antibodies on organ allocation.

Technological advances in the field of histocompatibility have allowed us to define anti-human leukocyte antigen (HLA) antibody specificity at the allelic level. However, how allele-specific antibodies affect organ allocation is poorly studied. We examined allelic specificities of class I HLA antibodies in 6726 consecutive serum samples from 2953 transplant candidates and evaluated their impact on the corresponding crossmatch and organ allocation. Out of 17 class I HLA antigens represented by >1 allele in the LABScreen single antigen bead assay, 12 had potential allele-specific reactivity. Taking advantage of our unbiased cohort of deceased donor-candidate testing (123,135 complement-dependent cytotoxicity crossmatches between 2014 and 2017), we estimated that the presence of allele-specific antibody detected using a single antigen bead assay (median fluorescence intensity, >3000) against only the rare allele was a poor predictor of a positive complement-dependent cytotoxicity crossmatch, with a positive predictive value of 0% to 7%, compared with 52.5% in allele-concordant class I HLA antibodies against A or B locus antigens. Further, we confirmed allele-specific reactivity using flow crossmatch in 3 scenarios: A11:01/A11:02, A68:01/A68:02, and B44:02/B44:03. Our results suggest that allele-specific antibodies may unnecessarily exclude transplant candidates (up to 10%) from organ offers by overcalling unacceptable antigens; incorporation of selective reactivity pattern in allocation may promote precision matching and more equitable allocation.

An 11-year-old girl with Autoimmune Polyglandular Syndrome (APS) type 2: a case report and review of literature.

OBJECTIVES: Autoimmune polyglandular syndrome type 2 (APS2) is characterized by autoimmune adrenal insufficiency (AI) in conjunction with autoimmune thyroid disease (AITD) and/or type 1 diabetes mellitus (T1DM). The aim is to report an 11-year-old girl with concurrence of Addison disease, celiac disease and thyroid autoimmunity. CASE PRESENTATION: She initially presented at the age of 5 with vomiting, dehydration, hyponatremia, hyperkalemia and low glucose. She recovered with intravenous hydration but the diagnosis was not established. She presented again at the age of 11 with hyperpigmentation, weakness and signs of impending adrenal crisis. Diagnosis of autoimmune AI was established together with celiac disease and thyroid autoimmunity. Thus, she met criteria for APS, being the third pediatric case report of APS2 with this combination. CONCLUSIONS: This case is notable for the atypical age of onset, given that APS2 is rare in the pediatric population. Furthermore, it depicts the insidious course of Addison disease with symptoms fluctuating for years before diagnosis.

Hypertriglyceridemic Waist Phenotype and Its Association with Metabolic Syndrome Components, among Greek Children with Excess Body Weight.

The hypertriglyceridemic waist (HTGW) phenotype is characterized by abdominal obesity and elevated serum triglycerides. We aimed to assess the prevalence of the HTGW phenotype among children with overweight or obesity and its association with indices of insulin resistance (IR) and dyslipidemia. A total of 145 children with mean age of 10.2 years (SD = 2.31 years), 97.2% of whom with obesity, were analyzed. The HTGW phenotype was defined as WC > 90th Centers for Disease Control and Prevention (CDC) percentile and triglyceride levels of ≥100 mg/dL and ≥130 mg/dL for children 0 to 9 or >10 years of age, respectively. In total, 77.9% of the children had a waist circumference above the 90th percentile and 22.8% had elevated triglycerides. The prevalence of the HTGW phenotype in this sample was 19.3%. Patients with the HTGW phenotype had significantly lower levels of High-Density Lipoprotein (p < 0.001) and were insulin-resistant, as evident by an increased mean Triglycerides Glucose Index 8.64 (SD = 0.24) vs. 7.92 (SD = 0.41) for those without the HTGW phenotype (p < 0.001), and increased prevalence (54.5%) of Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) in ≥2.5 in patients with HTGW (p = 0.045). Children with the HTGW phenotype were more likely to have increased HOMA-IR [OR 7.9 95% CI (1.94, 32.1)]. The HTGW phenotype is a low-cost and easily available index that might help to identify children with increased cardiometabolic risk.

3ß-Hydroxysteroid Dehydrogenase Type 2 (3ßHSD2) Deficiency due to a Novel Compound Heterozygosity of a Missense Mutation (p.Thr259Met) and Frameshift Deletion (p.Lys273ArgFs*7) in an Undervirilized Infant Male with Salt Wasting.

Deficiency of 3ß-hydroxysteroid dehydrogenase type 2 (3ßHSD2) is a rare type of congenital adrenal hyperplasia (CAH), causing impaired steroid hormone production in both adrenals and gonads. Phenotype ranges, according to the genetic defect, from the salt-wasting form in both sexes to undervirilization in males and virilization in females. We present a 13-month-old male infant who was admitted to the hospital with signs of adrenocortical insufficiency and genital ambiguity. Clinical presentation, hormonal profile, laboratory evaluation, and karyotype were suggestive of the salt-wasting form of CAH due to 3ßHSD2 deficiency. Mutational analysis revealed a missense mutation c.776C>T (p.Thr259Met), inherited by the mother, and a frameshift deletion c.818-819delAA (p.Lys273ArgFs*7), inherited by the father. Both mutations are considered pathogenic. To our knowledge this is the first case of an undervirilized male infant with salt wasting bearing this pathogenic frameshift deletion p.Lys273ArgFs*7 in compound heterozygosity with the missense mutation p.Thr259Met.

Τriglycerides-glucose (TyG) index is a sensitive marker of insulin resistance in Greek children and adolescents.

PURPOSE: To investigate the association between Triglyceride-glucose (TyG) index and the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) and Matsuda indices in Greek obese children and adolescents, in order to assess whether it could be used as a predictor of insulin resistance. METHODS: 367 children (47.7% boys) with mean age of 9.9 ± 2.3 years, who were investigated for obesity, were included. After overnight fasting, TyG and HOMA-IR indices were calculated in all participants. In a subpopulation of 72 children Matsuda index was also calculated. RESULTS: 48.8% and 36.1% of the participants had insulin resistance according to HOMA-IR and Matsuda index respectively. TyG was significantly and positively correlated with BMI, ΗΟΜΑ-IR, lipid profile and Matsuda index. ROC curve analysis for TyG showed that the optimal cutoff value for the prediction of insulin resistance (HOMA-IR) was 7.96 with sensitivity 65% and specificity 58%. The area under the curve (AUC) was 0.65 which significantly differs from 0.5 (p < 0.001). Similarly, the optimal cutoff value of TyG index for predicting insulin resistance as evidenced by Matsuda was 7.91 with sensitivity 85% and specificity 61%. The AUC was 0.75 (p < 0.001). The odds for insulin resistance (with HOMA-IR) was 2.54 times greater for subjects with TyG higher than 7.96, while the odds for insulin resistance (with Matsuda) was 8.56 times greater for subjects with TyG more than 7.91. CONCLUSIONS: TyG index shows a positive correlation with insulin resistance among children and adolescents, however further studies are needed to clarify its predictive ability.

Cortisol response to adrenocorticotropin testing in non-classical congenital adrenal hyperplasia (NCCAH).

BACKGROUND: The adequacy of cortisol response in non-classical congenital adrenal hyperplasia (NCCAH) has not been fully elucidated. The aim was to evaluate cortisol response to adrenocorticotropin (ACTH) stimulation test in children and adolescents with NCCAH and heterozygotes for CYP21A2 gene mutations. METHODS: One hundred and forty-six children and adolescents, mean age 7.9 (0.7-17.5) years with clinical hyperandrogenism, were evaluated retrospectively. Thirty-one subjects had NCCAH, 30 were heterozygotes for CYP21A2 gene mutations, while 85 showed normal response to ACTH test. RESULTS: Baseline cortisol levels did not differ among NCCAH, heterozygotes, and normal responders: 15.75 (5.83-59.6) µg/dL vs. 14.67 (5.43-40.89) µg/dL vs. 14.04 (2.97-34.8) µg/dL, p=0.721. However, NCCAH patients had lower peak cortisol compared to heterozygotes and control group: 28.34 (12.25-84.40) vs. 35.22 (17.47-52.37) µg/dL vs. 34.92 (19.91-46.68) µg/dL, respectively, p=0.000. Peak cortisol was <18 µg/dL in 7/31 NCCAH patients and in one heterozygote. CONCLUSIONS: A percentage of 21.2% NCCAH patients showed inadequate cortisol response to ACTH stimulation. In these subjects, the discontinuation of treatment on completion of growth deserves consideration.

Antibodies against HLA-DP recognize broadly expressed epitopes.

HLA matching and avoidance of pre-transplant donor-specific antibodies are important in selection of donors for solid organ transplant. Solid phase testing with single antigen beads allows resolution of antibody reactivity to the level of the allele. Single antigen bead testing results at a large transplant center were reviewed to identify selective reactivity patterns of anti-HLA antibodies. Many HLA-DP antibodies were identified in the context of other HLA antibodies, but some sera had antibodies against only HLA-DP. B cell flow crossmatch testing was positive for 2 out of 9 sera with HLA-DP antibodies. Many patterns of reactivity corresponded to epitopes in hypervariable regions C and F of DPB1, but some matched epitopes in other regions or DPA1. Through analysis of single antigen bead testing from a large number of patients, we report that anti-HLA-DP antibodies predominantly recognize broadly cross-reactive epitopes. The United Network for Organ Sharing has mandated HLA-DP typing on all deceased kidney donors, and HLA-DP epitopes should be considered as the major antigens for avoidance of pre-transplant donor-specific antibodies.

Clinical evaluation of the endothelial tie-2 crossmatch in ABO compatible and ABO incompatible renal transplants.

The necessity of detection of other than the classical major histocompatibility complex (MHC) and MHC class I-related chain A (MICA) directed antibodies prior to organ transplantation has already been repeatedly reported. A commercial flow cytometric endothelial crossmatch (CM) using isolated peripheral blood tie-2 positive cells provides a tool to detect non-MHC antibodies in addition to antibodies directed to MHC class I and II. The vast majority of circulating tie-2 positive cells expresses HLA-DR but not the A, B blood group antigens. Tie-2 cells are circulating surrogate endothelial cells. In this retrospective study we evaluated the endothelial CM in 51 renal transplantations, 30 with ABO compatible grafts and 21 with ABO incompatible grafts. Fifteen of the ABO compatible recipients (group A) developed unexplained rejection episodes (RE) while the remaining 15 had no RE (group B). Five cases of group A and none of group B had a positive tie-2 CM before transplantation (p=0.042). A positive tie-2 CM was also correlated with graft failure in ABO compatible transplants (p=0.02). No significant correlation was found between a positive pre-transplant tie-2 CM and RE in the ABO incompatible group. This study strongly suggest that a positive tie-2 CM may predict post-transplantation complications in ABO compatible grafts while negative reactions are not predictive. The test is not significantly correlated with RE in ABO incompatible grafts possibly due to applied desensitization.

IgM antibodies towards pre-endothelial cells: strong indication for an association with accelerated rejection. A case report.

A 27-year-old woman developed a graft loss due to an accelerated humoral rejection after receiving a blood group identical, human leucocyte antigens (HLA) haploidentical living-related kidney, despite the fact that she did not refer any sensitization event before transplantation. The complement-dependent cytotoxicity and flow cytometry crossmatches were negative for T and B cells. Retrospectively, IgM antibodies against donor precursor endothelial Tie-2(+) cells were detected using a commercially available assay and the pre-transplant serum sample. This case illustrates the necessity of detection of other than the classical HLA-directed antibodies prior organ grafting.