Mutational spectrum of steroid 21-hydroxylase and the genotype-phenotype association in Middle European patients with congenital adrenal hyperplasia.

OBJECTIVE: To analyze the mutational spectrum of steroid 21-hydroxylase (CYP21) and the genotype- phenotype correlation in patients with congenital adrenal hyperplasia (CAH) registered in the Middle European Society for Pediatric Endocrinology CAH database, and to design a reliable and rational approach for CYP21 mutation detection in Middle European populations. DESIGN AND METHODS: Molecular analysis of the CYP21 gene was performed in 432 CAH patients and 298 family members. Low-resolution genotyping was performed to detect the eight most common point mutations. High-resolution genotyping, including Southern blotting and sequencing was performed to detect CYP21 gene deletions, conversions, point mutations or other sequence changes. RESULTS: CYP21 gene deletion and In2 and Ile172Asn mutation accounted for 72.7% of the affected alleles in the whole study group. A good genotype-phenotype correlation was observed, with the exception of Ile172Asn and Pro30Leu mutations. In 37% of patients low resolution genotyping could not identify the causative mutation or distinguish homozygosity from hemizygosity. Using high-resolution genotyping, the causative mutations could be identified in 341 out of 348 analyzed patients. A novel mutation Gln315Stop was found in one simple virilising CAH (SV-CAH) patient from Austria. In the remaining seven patients polymorphisms were identified as the leading sequence alteration. The presence of elevated basal and ACTH-stimulated 17-hydroxyprogesterone, premature pubarche, advanced bone age and clitoral hypertrophy directly implicated Asn493Ser polymorphism in the manifestation of nonclassical- (NC) and even SV-CAH. CONCLUSIONS: By genotyping for the most common point mutations, CYP21 gene deletion/conversion and the 8 bp deletion in exon 3, it should be possible to identify the mutation in 94-99% of the diseased alleles in any investigated Middle European population. In patients with a mild form of the disease and no detectable mutation CYP21 gene polymorphisms should be considered as a plausible disease-causing mutation.

[Normal course of autoimmune thyroid disease in diabetic children]. / Prirozený prubeh autoimunitního onemocnení stítné zlázy u diabetických detí.

BACKGROUND: Autoimmune thyroid disease (AITD) represents the most frequent associated manifestation of the autoimmune disease in children with Type 1 diabetes mellitus (T1DM). The aim of the study was to evaluate the prevalence and natural course of AITD in unselected cohort of diabetic children. METHODS AND RESULTS: TSH, free thyroxin, thyreoglobulin autoantibodies (Ab-hTG), peroxidase autoantibodies (Ab-TPO) and thyroid sonography were prospectively evaluated (1 to 6 years; 323 patient-years) in 110 patients with T1DM (age 2.1-20.8 years; 60 boys). Mild elevation of Ab-hTG and/or Ab-TPO levels (> 100, < 1000 mIU/l) was found in 19 patients (17%; boys:girls 1:2.2). Out of these, only 2 had increased thyroid volume and/or abnormal echotexture. In 9 of these patients, levels of autoantibodies subsequently declined below 100 mIU/l, remained unchanged in 9 patients and only in one case increased over 1000 mIU/l ("benign form" of AITD). All patients remained euthyroid. Severe elevation of Ab-hTG and/or Ab-TPO (> 1000 mIU/l) was found in 12 patients (11%; boys:girls 1:1). Out of these, eight had increased thyroid volume and ten had abnormal echotexture. Subclinical hypothyroidism developed within the observation period in nine of them (boys:girls 2:1). CONCLUSIONS: AITD was found in 31 (28%) children and adolescents with T1DM. Whereas mild elevation of Ab-hTG and/or Ab-TPO levels was not accompanied with morphological changes of the thyroid and did not predict functional disorder, severely elevated levels were associated with the early risk of subclinical hypothyroidism.

Immune system in adults with childhood-onset growth hormone deficiency: effect of growth hormone therapy.

OBJECTIVE: To investigate the impact of growth hormone (GH) therapy in adults with childhood-onset GH deficiency on immune system. METHODS: Ten young GH deficient adults (7 males, age 19-28 years) were treated with recombinant human growth hormone for 6 months. The starting dose was 0.5 IU/m2/day (2 weeks), then it was doubled to 1.0 IU/m2/day. In 5/10 patients, the dose was further increased to 1.5 IU/m2/day at 4 weeks of therapy. Immunological studies were performed before treatment and after 6 weeks, 3 months and 6 months and included humoral (IgG, IgA, IgM, C3, C4 and immune complexes) and cellular parameters (total lymphocyte count and counts of CD3+, CD4+, CD8+ and CD19+ lymphocytes, the CD4+/CD8+ ratio and percentage of CD16+56+ and CD3+DR+). RESULTS: The cellular responses to GH therapy were subtle, but detectable, with the trend to the higher CD4+ and lower CD8+ lymphocytes and maximal changes at 6 months of therapy. They were reflected in CD4/CD8 ratio, which increased from 1.15 +/- 0.10 (mean +/- S.E.; baseline) to 1.37 +/- 0.11 (6 weeks; P < 0.05), 1.24 +/- 0.10 (3 months; n.s.) and to 1.59 +/- 0.20 (6 months; P < 0.05). The response in humoral immunity was characterized by a rapid decrease of circulating immunoglobulins (IgA: 1.40 +/- 0.25 g/l [mean+/-S.E.], baseline; 1.12 +/- 0.19, at 6 weeks; P < 0.05) and C4 (0.25 +/- 0.02 g/l, baseline; 0.19 +/- 0.01, at 6 weeks; P < 0.05) and a tendency to an increase in circulating immune complexes (29.1 +/- 8.1, baseline; 40.3 +/- 7.2, at 6 weeks; n.s.). These observations suggest a temporary immune complex formation after the onset of GH treatment which might play a partial role in developing oedema as a side effect of GH treatment, besides the known effect of GH on water retention. CONCLUSIONS: GH therapy in GH deficient young adults has a measurable effect on the increase of CD4/CD8 ratio and on the formation of immune complexes.