Distinct immune trajectories in patients with chromosome 22q11.2 deletion syndrome and immune-mediated diseases.

BACKGROUND: Identification of biomarkers associated with immune-mediated diseases in 22q11.2 deletion syndrome is an evolving field. OBJECTIVES: We sought to use a carefully phenotyped cohort to study immune parameters associated with autoimmunity and atopy in 22q11.2 deletion syndrome to define biomarkers associated with immune-mediated disease in this syndrome. METHODS: Chart review validated autoimmune disease and atopic condition diagnoses. Laboratory data were extracted for each subcohort and plotted according to age. A random-effects model was used to define statistical significance. RESULTS: CD19, CD4, and CD4/45RA lymphocyte populations were not different from the general cohort for patients with atopic conditions. CD4/45RA T cells were significantly lower in the subjects with immune thrombocytopenia compared with the general cohort, and CD4 T-cell counts were lower in patients with autoimmune thyroid disease. CONCLUSIONS: The mechanisms of autoimmunity in cytopenias may be distinct from those of solid-organ autoimmunity in 22q11.2 deletion syndrome. This study identifies potential biomarkers for risk stratification among commonly obtained laboratory studies.

Clinical Features in a Large Cohort of Patients With 22q11.2 Deletion Syndrome.

OBJECTIVES: To evaluate various clinical aspects, specifically regarding immune status, in a large cohort of patients with DiGeorge syndrome. STUDY DESIGN: Data were collected for 98 patients with DiGeorge syndrome treated at a tertiary medical center. This included general information, laboratory results, and clinical features. RESULTS: The median age at diagnosis was 2.0 years (range, 0.0-36.5 years). The most common symptoms that led to diagnosis were congenital heart defect, speech delay, palate anomalies, and developmental delay. Common clinical features included recurrent infections (76 patients), congenital heart diseases (61 patients), and otorhinolaryngology disorders (61 patients). Twenty patients had anemia; the incidence was relatively high among patients aged 6-59 months. Thrombocytopenia was present in 20 patients. Recurrent chest infections were significantly higher in patients with T cell and T cell subset deficiencies. Decreased T cell receptor excision circles were more common with increasing age (P < .001). Of the 27 patients hospitalized due to infection, pneumonia was a leading cause in 13. CONCLUSIONS: Awareness of DiGeorge syndrome's typical and uncommon characteristics is important to improve diagnosis, treatment, surveillance, and follow-up.

Low thymic output, peripheral homeostasis deregulation, and hastened regulatory T cells differentiation in children with 22q11.2 deletion syndrome.

OBJECTIVE: To perform an extensive analysis of the immune status of asymptomatic children with the 22q11.2 deletion syndrome, with special emphasis on the regulatory T cells (Treg) population. STUDY DESIGN: Analysis of thymic function, frequency and absolute counts of immune subsets, and phenotype of Treg were performed in 10 asymptomatic children bearing the 22q11.2 deletion and compared with 12 age-matched, healthy children. RESULTS: Children with 22q11.2 deletion syndrome showed a curtailed thymic output, lower T-cell levels, and a homeostatic deregulation in the CD4 T-cell compartment, characterized by a greater proliferative history in the naïve CD4 T-cell subset. Treg numbers were markedly reduced in children with 22q11.2 deletion syndrome, and remaining Treg showed mostly an activated phenotype. CONCLUSIONS: Reduced thymic output in children with 22q11.2 deletion syndrome could be related with an increased proliferation in the naïve CD4 T-cell compartment and the consequent Treg activation to ensure that T-cell expansion remains under control. Deregulated peripheral homeostasis and loss of suppressive capacity by Treg could compromise the integrity of T-cell immunity during adulthood and play a relevant role in the increased incidence of autoimmune diseases reported in patients with the 22q11.2 deletion syndrome.

22q11.2 deletion syndrome with life-threatening adenovirus infection.

Adenovirus causes significant morbidity and mortality in immunocompromised children. We report how an infusion of HLA-matched sibling donor T lymphocytes rapidly eradicated life-threatening, high-level adenoviremia in a child with complete DiGeorge syndrome (22q11.2 deletion) who went on to reconstitute a diverse, donor-derived, postthymic T-cell repertoire.

Autoimmune thrombocytopenic purpura in partial DiGeorge syndrome: case presentation.

The absence of an appropriate central tolerance in primary immunodeficiencies favors proliferation of autoreactive lymphocyte clones, causing a greater incidence of autoimmunity. Del 22q11.2 syndrome presents an increased incidence of allergic and autoimmune diseases. One of the most relevant and frequent immune manifestations is autoimmune thrombocytopenia. We present the case of a pediatric patient with autoimmune thrombocytopenia due to the immunological dysregulation observed in partial DiGeorge syndrome.

Síndrome de DiGeorge: Aspectos clínico-imunológicos e manejo / DiGeorge Syndrome: Clinical-immunologic aspects and management

Objetivo: revisar a literatura sobre a Síndrome de DiGeorge (SDG) com ênfase para as principais manifestações clínicas e abordagens diagnóstica e terapêutica. Fonte de dados: Literatura médica publicada sobre o assunto nos últimos dez anos utilizando PubMed, MEDLINE e livros médicos especializados. Palavras chave usadas na pesquisa: Síndrome de DiGeorge, FISH, síndrome Velo-cárdio-facial, imunodeficiência primária, infecções recorrentes. Síntese de dados: A SDG é distúrbio congênito resultante da migração anormal das células embrionárias da terceira e quarta bolsas faríngeas, levando a hipo ou aplasia do ti mo, defeitos da paratireóide, arco aórtico e imunodeficiência celular. Além de hipocalcemia neonatal e dismorfismos faciais tipicos, as alterações observadas ocorrem principalmente nos sistemas imunológico e cardiovascular. Os principais defeitos cardíacos relatados são: Anomalia conotruncal, interrupção do arco aórtico e Tetralogia de Fallot. Quanto às anormalidades do sistema imunológico, os pacientes podem ser assintomáticos ou cursar com defeitos graves de células T, dependendo do grau de comprometimento tímico. Conclusões: O diagnóstico, após suspeição clínica deve ser confirmado pelo teste FISH. O manejo destes pacientes visa principalmente o controle das infecções de repetição, correção dos distúrbios cardíacos e controle de co-morbidades. O tratamento definitivo nos casos mais graves é o transplante tímico, com resultados promissores

O papel do timo no desenvolvimento do sistema imune / The role of the thymus in the development of the immune system

Objetivo: discutir e atualizar informações relevantes sobre o papel do timo no desenvolvimento dos linfócitos T, na tolerância aos próprios antígenos, e na manutenção da homeostase do sistema imunológico. fonte dos dados: revisões, artigos e livros contendo informações relevantes e atuais. Síntese de dados: o timo é um órgão linfóide primário, essencial para o estabelecimento inicial de um repertório...

Objective: to discuss and update relevant information on the role of the thymus in the development of T lymphocytes, in the tolerance to the antigens and in the maintenance of the immunological system homeostasis. Data source: literature reviews, studies and books containing relevant and current information. Data synthesis: the thymus is a primary lymphoid organ, essential for the initial establishment of a functional T-cell reservoir in humans...

[Clinical findings and immunologic variability in 9 patients with DiGeorge syndrome]. / Manifestaciones clínicas y variabilidad inmunológica en nueve pacientes con síndrome de DiGeorge.

BACKGROUND: DiGeorge syndrome is characterized by developmental defects of the heart, parathyroid glands and thymus. AIM: To describe the clinical variability of DiGeorge syndrome and its relation with immunodeficiency. PATIENTS AND METHODS: A three years retrospective chart review from three hospitals of Santiago, Chile was conducted. We included patients with neonatal diagnosis of DiGeorge syndrome. Clinical and immunologic data were collected from their initial evaluation. RESULTS: We found 9 patients with DiGeorge syndrome. All had dysmorphic facies, hypocalcemia and congenital heart disease. Three patients had hypoparathyroidism, 4 had interrupted aortic arch type B, 4 had tetralogy of Fallot and 1 had coarctation of aorta. Six patients had other malformations and associated diseases. FISH studies, performed in 8 patients, found the 22q11.2 microdeletion in all. Most patients had low CD3, CD4 and CD8 T cell counts, that ranged for CD3 T cells, between 256/mm3 and 3,664/mm3, for CD4 T cells, between 224/mm3 and 2,649/mm3, for CD8 T cells, between 26/mm3 and 942/mm3. Three patients had CD4 T cells counts <400/mm3 and one had a phytohemagglutinin stimulation index <10. Airway malformations and primary hypoparathyroidism were present in 3 out of 4 patients that died before 18 months compared with the surviving patents (p=0.048). CONCLUSIONS: We found variable clinical manifestations as well as CD3, CD4 and CD8 T cell counts in patients with DiGeorge syndrome. Airway malformations were associated with a higher mortality.

Manifestaciones clínicas y variabilidad inmunológica en nueve pacientes con síndrome de DiGeorge / Clinical findings and immunologic variability in 9 patients with DiGeorge syndrome

Background: DiGeorge syndrome is characterized by developmental defects of the heart, parathyroid glands and thymus. Aim: To describe the clinical variability of DiGeorge syndrome and its relation with immunodeficiency. Patients and methods: A three years retrospective chart review from three hospitals of Santiago, Chile was conducted. We included patients with neonatal diagnosis of DiGeorge syndrome. Clinical and immuno-logic data were collected from their initial evaluation. Results: We found 9 patients with DiGeorge syndrome. All had dysmorphic facies, hypocalcemia and congenital heart disease. Three patients had hypoparathyroidism, 4 had interrupted aortic arch type B, 4 had tetralogy of Fallot and 1 had coarctation of aorta. Six patients had other malformations and associated diseases. FISH studies, performed in 8 patients, found the 22q11.2 microdeletion in all. Most patients had low CD3, CD4 and CD8 T cell counts, that ranged for CD3 T cells, between 256/mm3 and 3,664/mm3, for CD4 T cells, between 224/mm3 and 2,649/mm3, for CD8 T cells, between 26/mm3 and 942/mm3. Three patients had CD4 T cells counts <400/mm3 and one had a phytohemagglutinin stimulation index <10. Airway malformations and primary hypoparathyroidism were present in 3 out of 4 patients that died before 18 months compared with the surviving patients (p=0.048). Conclusions: We found variable clinical manifestations as well as CD3, CD4 and CD8 T cell counts in patients with DiGeorge syndrome. Airway malformations were associated with a higher mortality (Rev Méd Chile 2004; 132: 26-32).

Infecciones asociadas a inmunodeficiencias primarias 1970-1994 servicio anatomía patológica Hospital Miguel Pérez Carreño / Infections associated immunodeficiency primary 1970-1994 service pathological anatomy Hospital Miguel Pérez Carreño

Las inmunodeficiencias primarias son un aspecto de la patología inmunitaria aún en estudio, de gran relevancia a lo que contribuye la serie estudiada de pacientes con inmunodeficiencias primarias. Se realizó un estudio restrospectivo en registros de patología del Hospital Miguel Pérez Carreño donde se encontraron 2.244 autopsias (período 1970-1994). De éstas 10(0,4 por ciento) correspondieron con inmunodeficiencias primarias. Con el fin de estudiar sus complicaciones infecciosas y aspectos clínicos patológicos, se revisaron las autopsias con el diagnóstico de inmunodeficiencias primarias, en relación a complicaciones infecciosas. El material fue procesado y evaluado conforme a técnicas estándar. Los resultados fueron expresados en términos absolutos, porcentuales y promediales, usando la prueba de T de Student (grado de confianza de 95 por ciento; p<0,05). Los casos de inmunodeficiencias primarias, todos presentaron alguna complicación infecciosa. La edad promedio fue de 6,4 ± 5,7 meses (70 por ciento lactantes menores (30 por ciento lactantes mayores) (p>0,05). Seis casos (60 por ciento) fueron masculinos y 4 (40 por ciento) femeninos (p<0,05). En relación con el tipo de inmunodeficiencia primaria, correspondieron principalmente con Sindrome de DiGeorge (40 por ciento) (p<0,005) e inmunodeficiencia combinada (20 por ciento). Se encontró que el 60 por ciento presentó infección respiratoria baja (p<0,05), 40 por ciento presentó enterocolitis bacteriana, en tanto que 30 por ciento tuvieron diarrea. Sería interesante concluir haciéndonos la interrogante de que, si las infecciones respiratorias y más aún las diarreas, dada su morbilidad en 5 años, cuantos casos que fallecen no se han llevado consigo como secreto un diagnóstico no realizado de una inmunodeficiencia primaria

Immunologic features of chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome).

OBJECTIVES: To characterize immunologic function and clinical characteristics in patients with chromosome 22q11.2 deletion syndrome and determine whether there was significant change over time. METHODS: This study characterized the laboratory and clinical features of the immunodeficiency in a cohort of 195 patients with chromosome 22q11.2 deletion syndrome and used cross-sectional and analysis of variance to compare the findings in different age groups with control patients. Changes over time were also characterized by a model effect method in a subset of patients who were studied serially. RESULTS: Diminished T cell counts in the peripheral blood are common in patients with chromosome 22q11.2 deletion syndrome. The pattern of changes seen with aging in normal control patients was also seen in patients with chromosome 22q11.2 deletion syndrome, although the decline in T cells was blunted. Autoimmune disease was seen in most age groups, although the types of disorders varied according to age. Infections were also common in older patients, though they were seldom life threatening. CONCLUSIONS: Slow declines in T cell populations are seen in chromosome 22q11.2 deletion syndrome. Clinical manifestations of immunodeficiency, such as recurrent infection and autoimmune disease, were common in this population but had little relationship to specific immunologic laboratory features.

Complete DiGeorge syndrome: persistence of profound immunodeficiency.

OBJECTIVE: DiGeorge syndrome is characterized by developmental defects of the heart, parathyroid glands, and thymus. The objective of this study was to determine whether T-cell function spontaneously improves in patients with DiGeorge syndrome who have profoundly depressed T-cell proliferative responses to mitogens at presentation, regardless of the T-cell count. STUDY DESIGN: We conducted a retrospective chart review of eight patients with DiGeorge syndrome who had no proliferative responses to mitogens on presentation. RESULTS: Despite lack of responsiveness of the patients' peripheral blood lymphocytes to mitogens, T cells were occasionally detected, and the patients' cells often responded to IL-2 and in mixed lymphocyte reactions. Unresponsiveness to mitogens and clinical immunodeficiency persisted without immune-based therapy. One patient is alive and well after immunoreconstitution from thymic transplantation. The others either died early of complications of their disease such as gastroesophageal reflux with aspiration (2 patients) or infection (2 patients) or died after attempts at immunorestorative therapy with IL-2, thymus transplantation, or bone marrow transplantation (3 patients). CONCLUSION: Eight patients with DiGeorge syndrome who were first seen with no mitogen responsiveness did not improve spontaneously. We recommend HLA-identical bone marrow transplantation or thymic transplantation for these patients as soon as the diagnosis is confirmed.

Recurrent immune cytopenias in two patients with DiGeorge/velocardiofacial syndrome.

We describe two patients with clinical and cytogenetic findings consistent with DiGeorge/velocardiofacial syndrome who had recurrent cytopenias at presentation. Our observations suggest that recurrent cytopenias may be part of the clinical spectrum of deletion 22q11.2. We also suggest that the diagnosis of DG/VCF syndrome be considered in patients with unexplained recurrent immune cytopenias in association with cardiac lesions, subtle craniofacial dysmorphisms, and/or learning or behavioral impairments.

Humoral immunity in DiGeorge syndrome.

OBJECTIVE: To assess humoral immunity after immunization and natural infection in patients with clinical manifestations of the DiGeorge anomalad. DESIGN: Retrospective review of cases. SETTING: Ambulatory immunology clinic of a tertiary care teaching hospital. PATIENTS: The 13 patients had a symptom complex including congenital heart disease, characteristic facies of the DiGeorge anomalad, possible hypocalcemia, and thymic hypoplasia or aplasia. Molecular and cytogenic studies of 12 patients demonstrated that all had 22q11 microdeletions. METHODS: Serial studies included lymphocyte population enumeration by flow cytometry, lymphocyte proliferation assays with the mitogens phytohemagglutinin and pokeweed mitogen and Staphylococcus aureus, and immunoglobulin quantitation. Specific antibody studies included virus neutralization assays for poliovirus antibodies, and enzyme-linked immunosorbent assay for diphtheria, tetanus, measles, rubella, varicella-zoster virus (VZV), and cytomegalovirus (CMV) antibodies. Avidity of rubella, VZV, and CMV antibodies was tested by enzyme-linked immunosorbent assay modified to include a mild protein denaturant in the first wash after incubation with sera. RESULTS: All patients had a CD3+ cell count greater than 0.500 x 10(9)/L and a CD4+ cell count greater than 0.350 x 10(9)/L). One patient had low proliferation responses to S. aureus, and one to phytohemagglutinin and pokeweed mitogen. Immunoglobulin levels, compared with those in age-related control subjects, were normal except that two patients had transient, borderline low IgG levels and two had elevated IgA levels. Specific antibody tests showed (No. of patients with positive results/No. tested) the following: diphtheria (13/13); tetanus (13/13); poliomyelitis caused by polio virus type 1 (5/9), type 2 (9/9), and type 3 (8/9); measles (11/13); rubella (11/13); and infection with VZV (5/5) and CMV (7/13). There were no significant differences in antibody avidity results between patients and control subjects for rubella (mean avidity index, 83.5 +/- 8.79 vs 85 +/- 17.6), VZV (81.6 +/- 3.98 vs 65.1 +/- 12.38), or CMV (69.3 +/- 22.31 vs 73.3 +/- 12.46). CONCLUSIONS: Patients with "partial" DiGeorge anomalad, defined by clinical and immunologic criteria, can be immunized and for the most part can generate good antibody responses.

Estudio inmunogenético de un caso de síndrome de DiGeorge / Immunogenetic study of one case in DiGeorge syndrome

El síndrome de DiGeorge es una inmunodeficiencia congénita de rara presentación, clínicamente caracterizado por la tetania hipocalcémica, enfermedad cardiaca congénita, fascies poco común, aumento de la susceptibilidad a la infección. Desde el punto de vista patológico el síndrome de DiGeorge es una forma de alteración en el desarrollo embriológico. Desde el punto de vista genético se ha encontrado pérdida de la porción proximal del brazo largo del cromosona 22. Quienes padecen este síndrome tienen un gran número de alteraciones que pueden cursar con grados variables, lo que ha permitido tres formas de manifestación: completa, parcial y transitoria

[Immunogenetic study in a case of DiGeorge syndrome]. / Estudio inmunogenético de un caso de síndrome de DiGeorge.

DiGeorge Syndrome is a congenital immunodeficiency characterized clinically by hypocalcemic tetany, congenital heart disease, unusual facies, and increased susceptibility to infection. Pathologically, the syndrome is marked by the abscence or hipoplasia of the thymus and parathyroid glands as well as cardiac or aortic arch abnormalities. Most patients show partial or complete T cell immunodeficiency and normal or near-normal B-cell immunity. A review is made on a clinical case of DiGeorge syndrome is presented. A 52 days old boy, was admitted through emergency. There was no familial evidence of alcoholism or immunodeficiency. He showed irritability due to hypocalcemia. The examination revealed facial and cardiovascular abnormalities and the immunological investigation revealed hypogammaglobulinemia, deficiency of the cell, CD4 and CD8 decreased and with inverted relation. Chest X ray showed cardiomegaly grade II, and no thymus was seen. The diagnosis of the complete DiGeorge syndrome was based on the abnormalities found.

[Di George syndrome]. / Síndrome de Di George.

Two patients with Di George syndrome are presented. Diagnosis was done at ages 4 months and 16 days respectively. Their main clinical symptoms were hypocalcemic convulsions, unusual facies (hyperthelorism, low set prominent ears, micrognathia, short philtrum) and cardiac malformations (vascular ring with right aortic arc, aberrant left innominated artery and ligamentum arteriosus in one of them and Tetralogy of Fallot with pulmonary valve atresia in the other). The first patient is now a 3.5 year old boy, his vascular ring was repaired and he has hypoparathyroidism but no clinical nor laboratory evidence of cellular immunodeficiency. The other patient had evidence of heart failure at her second week of life, she died at age sixteen days and, at necropsy, Fallot's tetralogy with pulmonary valve atresia, closed ductus arteriosus, histologically normal ectopic thymus and absent parathyroid glands were demonstrated. We postulate that these cases correspond to partial forms of Di George syndrome.

Prediction of persistent immunodeficiency in the DiGeorge anomaly.

To assess the natural history of the immune defect in DiGeorge anomaly, we reviewed serial immunologic studies in 18 patients. The diagnosis was made with criteria based on the concept of the DiGeorge anomaly as a field defect. Initial or early follow-up laboratory examination suggested moderate to normal T cell function in 14 patients. None of these patients have lost T cell capability; they have never had infections characteristic of T cell deficiency. Four patients had clinical and laboratory evidence of profound immunodeficiency. A decreased number of CD4+ cells (less than 400/microliters) and a decrease in phytohemagglutinin responsiveness (stimulation index less than 10) may be useful in discriminating patients with immunodeficiency; absolute lymphocyte count and immunoglobulin values were not informative. At the time of surgery, the thymus was not found in 11 of 14 patients; however, only two of these patients had immunodeficiency. Patients with a persistently low number of CD4+ cells and decreased phytohemagglutinin response are candidates for immunologic reconstitution.