Current proposal covers systematic and prospective immunological investigation of a cohort of children with syndrome diGeorge. As a part of their genetic defect these patient have impaired development of thymus that substantially affects their immune functions. We plan to investigate in a prospective study not only T cells that were in past studied in detail, but also B cells potentially affected by impaired T cells help. We also plan to investigate T regulatory cells and T regulatory cells expressing Helios as a marker of thymus derived Tregs. We finally plan to correlate all these finding with age and clinical status of diGeorge children.

Předkládaný projekt se zabývá systematickým a prospektivním sledováním dětí se syndromem diGeorge. Součástí tohoto geneticky podmíněného syndromu je porucha funkce thymu, která následně ovlivňuje vývoj imunitního sysstému. V plánu tohto projektu je studium nejenom T lymfocytů, které byly již v minulosti opakovaně vyšetřovány a výsledky publikovány, ale také B lymfocytů a protilátkové odpovědi, s předpokladem jejich ovlivnění abnormální pomocí T lymfocytů. Tato vyšetření doplníme vyšetřováním T regulačních buněk, včetně T regs exprimujících Helios, který umožní odlišení Tregs pocházejících z thymu. Všechna data budou korelována s klinikou a věkem dětí. Souhrnná analýza umožní detailní zmapování vývoje imunity u dětí se syndromem diGeorge.

• MeSH
• B-lymfocyty cytologie   MeSH
• DiGeorgeův syndrom MeSH
• fenotyp MeSH
• průtoková cytometrie MeSH
• regulační T-lymfocyty MeSH
• syndrom delece 22q11 MeSH
• T-lymfocyty cytologie   MeSH
• thymus imunologie   MeSH
• transkripční faktor Ikaros MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• alergologie a imunologie
• genetika, lékařská genetika
• NLK Publikační typ
• závěrečné zprávy o řešení grantu IGA MZ ČR

PURPOSE: Patients with DiGeorge syndrome suffer from T-lymphopenia. T-cells are important for the maturation and regulation of B-cell function. Our aim was to characterize the B-cell compartment in DiGeorge syndrome patients. METHODS: B-cell subset phenotypization using flow cytometry. Serum BAFF (B-cell activating factor) and serum anti-alpha-galactosyl IgM measurement using ELISA. Serum IgG measurement using nephelometry. RESULTS: We observed a significantly increased number of naïve B-cells and decreased number of switched memory B-cells in DiGeorge patients. Furthermore, we observed increased BAFF levels and a trend toward hypergammaglobulinemia later in life. Surprisingly, we detected a decrease in marginal zone-like (MZ-like) B-cells and natural antibodies in DiGeorge patients. CONCLUSION: The maturation of B-cells is impaired in DiGeorge patients, with high naïve and low switched memory B-cell numbers being observed. There is a clear trend toward hypergammaglobulinemia later in life, coupled with increased serum BAFF levels. Surprisingly, the T-independent humoral response is also impaired, with low numbers of MZ-like B-cell and low levels of anti-alpha-galactosyl IgM natural antibodies being detected.

• MeSH
• DiGeorgeův syndrom imunologie   MeSH
• dítě MeSH
• dospělí MeSH
• faktor aktivující B-buňky imunologie   MeSH
• humorální imunita imunologie   MeSH
• hypergamaglobulinemie imunologie   MeSH
• imunoglobulin G imunologie   MeSH
• imunoglobulin M imunologie   MeSH
• imunologická paměť imunologie   MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• novorozenec MeSH
• podskupiny B-lymfocytů imunologie   MeSH
• předškolní dítě MeSH
• protilátky imunologie   MeSH
• studie případů a kontrol MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

UNLABELLED: DiGeorge syndrome (DGS) presents with a wide spectrum of thymic pathologies. Nationwide neonatal screening programs of lymphocyte production using T-cell recombination excision circles (TREC) have repeatedly identified patients with DGS. We tested what proportion of DGS patients could be identified at birth by combined TREC and kappa-deleting element recombination circle (KREC) screening. Furthermore, we followed TREC/KREC levels in peripheral blood (PB) to monitor postnatal changes in lymphocyte production. METHODS: TREC/KREC copies were assessed by quantitative PCR (qPCR) and were related to the albumin control gene in dry blood spots (DBSs) from control (n = 56), severe immunodeficiency syndrome (SCID, n = 10) and DGS (n = 13) newborns. PB was evaluated in DGS children (n = 32), in diagnostic samples from SCID babies (n = 5) and in 91 controls. RESULTS: All but one DGS patient had TREC levels in the normal range at birth, albeit quantitative TREC values were significantly lower in the DGS cohort. One patient had slightly reduced KREC at birth. Postnatal DGS samples revealed reduced TREC numbers in 5 of 32 (16%) patients, whereas KREC copy numbers were similar to controls. Both TREC and KREC levels showed a more pronounced decrease with age in DGS patients than in controls (p < 0.0001 for both in a linear model). DGS patients had higher percentages of NK cells at the expense of T cells (p < 0.0001). The patients with reduced TREC levels had repeated infections in infancy and developed allergy and/or autoimmunity, but they were not strikingly different from other patients. In 12 DGS patients with paired DBS and blood samples, the TREC/KREC levels were mostly stable or increased and showed similar kinetics in respective patients. CONCLUSIONS: The combined TREC/KREC approach with correction via control gene identified 1 of 13 (8%) of DiGeorge syndrome patients at birth in our cohort. The majority of patients had TREC/KREC levels in the normal range.

• MeSH
• biotest MeSH
• DiGeorgeův syndrom diagnóza   genetika   imunologie   MeSH
• dítě MeSH
• kojenec MeSH
• kruhová DNA genetika   MeSH
• kultivované buňky MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• lidé MeSH
• mladiství MeSH
• novorozenec MeSH
• novorozenecký screening * MeSH
• předškolní dítě MeSH
• syndromy imunologické nedostatečnosti diagnóza   genetika   imunologie   MeSH
• T-lymfocyty imunologie   MeSH
• těžká kombinovaná imunodeficience diagnóza   genetika   imunologie   MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

PURPOSE: Syndrome diGeorge is associated amongst other clinical signs with various degrees of thymic dysplasia, related immunodeficiency and autoimmune disorders. Helios, a transcription factor from Ikaros family, has been proposed as a marker for thymus derived Tregs. We therefore examined Helios + Tregs in a cohort of patients with genetically proven diGeorge syndrome with typical T cell lymphopenia due to the thymic pathology. METHODS: T cells, FoxP3+ Tregs and Helios + FoxP3+ Tregs were examined in 52 samples from 37 patients. One patient with diGeorge/CHARGE syndrome with total thymic aplasia was also included. Statistical analysis was performed using a linear regression comparison. RESULTS: Total absolute Tregs were significantly lower in diGeorge patients as compared to controls in all age groups (0-20 years) (p = 0.0016). The difference was more expressed in the first four years of age. Relative Treg numbers expressed as the percentage of Tregs in CD4+ T-cells, however, were not different in patients and controls in all age groups (p = 0.661), neither could we find any significant difference in the percentage of Helios + Tregs between patients and controls (p = 0.238). Helios + Tregs were still present in a patient with diGeorge/CHARGE syndrome with complete athymia 7 years after partially matched unrelated repeated T lymphocytes infusions. CONCLUSION: Our findings show that while there was a significant decrease in absolute numbers of Tregs in patients with diGeorge syndrome, the relative percentage of this population did not differ between patients and controls. Low absolute Tregs thus reflected typical T cells lymphopenia in patients. Helios expression was not affected in diGeorge syndrome.

• MeSH
• biologické markery metabolismus   MeSH
• DiGeorgeův syndrom imunologie   MeSH
• dítě MeSH
• dospělí MeSH
• forkhead transkripční faktory metabolismus   MeSH
• kohortové studie MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• novorozenec MeSH
• počet buněk MeSH
• předškolní dítě MeSH
• regulační T-lymfocyty imunologie   MeSH
• thymus imunologie   patologie   MeSH
• transkripční faktor Ikaros genetika   metabolismus   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH