Delecion 22q11.2: características de un grupo de pacientes atendidos en el Hospital Juan P. Garrahan / 22q11.2 deletions: features of a group of patients seen at the Juan P. Garrahan Hospital

El síndrome de Deleción 22q11.2 afecta el aparato cardiovascular, la inmunidad, las funciones endocrinológicas, la cavidad oral, el desarrollo neurocognitivo, con un fenotipo particular debido a una anomalía cromosómica. Objetivo: evaluar las características clínicas y citogenéticas de pacientes atendidos en forma multidisciplinaria, a través de un estudio observacional, descriptivo, transversal e interdisciplinario de una cohorte en seguimiento. Se diagnosticaron 194 pacientes con microdeleción 22q11.2, M 95/ F 99, con un rango etario: 0 a 192m (4días-16 a) y una mediana: 23m, el signo más constante fue la facies característica que se observó en un 100%, el 72,5% presentó malformación cardiovascular, 74,7% mostró defectos en su cavidad oral y el 30,5% hipoacusias. La mayoría de los pacientes evidenciaron compromiso de su neurodesarrollo en forma global, con retraso y trastorno de lenguaje. Se detectaron alteraciones en la inmunidad en el 64,31% con disminución de los linfocitos T, hipocalcemia en 36,8% y defectos urológicos en un 14,7%. Entre los diagnósticos citogenéticos se observó además dos pacientes con traslocaciones cromosómicos de novo que involucraban la microdeleción y un paciente con la deleción en mosaico. Los estudios parentales evidenciaron un 10% de casos heredados. La población estudiada mostró una clínica y frecuencia de anomalías similar a la referida en la bibliografía a excepción de los trastornos auditivos y urológicos que se vieron con menor frecuencia mientras que la prevalencia de alteraciones neurocognitivas fue mayor. La complejidad y variabilidad del síndrome requiere un manejo multidisciplinario.

22q11.2 deletion syndrome may affect the cardiovascular and immune systems, endocrine functions, the oral cavity, and neurocognitive development with a peculiar phenotype due to the chromosomal anomaly. Objective: To evaluate the clinical and cytogenetic features of patients followed-up by a multidisciplinary team in an observational, descriptive, cross-sectional and interdisciplinary cohort study. We diagnosed 194 patients with a 22q11.2 microdeletion, M 95/ F 99, with an age range of 0 to 192 months (4 days-16 years) and a me-dian age of 23 months. Characteristic facies was observed in 100% of the patients, cardiovascular malformation in 72.5%, oral cavity abnormalities in 74.7%, and hearing loss in 30.5%. The majority of the patients showed global impairment of neurological development, such as developmental delay and language disorders. Alterations in the immune system with a low T-lymphocyte count were found in 64.31% of the patients, hypocalcemia in 36.8%, and urinary abnormalities in 14.7%. Among the cytogenetic diagnoses, two patients were found to have de novo chromosome translocations involving the microdeletion and one patient had a mosaic deletion. Stud-ies in parents showed that the disease was inherited in 10% of the cases. Clinical findings and rate of anomalies in the study population were similar to those reported in the litera-ture, except for hearing loss and urinary disorders that were less frequently found, while the prevalence of neurocognitive impairment was higher. The complexity and variability of the syndrome warrants a multidisciplinay approach.

Clinical and histopathological features and a unique spectrum of organisms significantly associated with chronic granulomatous disease osteomyelitis during childhood.

Herein, we describe a combination of clinical, microbiologic, and histopathologic findings significantly associated with osteomyelitis in chronic granulomatous disease. When present, these features should raise the suspicion of underlying chronic granulomatous disease. In patients with these findings, anti-infective prophylactic measures aiming to cover highly prevalent microorganisms, as well as aggressive therapeutic measures, should be strongly encouraged.

Evolución de niños post-trasplante hepático luego del primer año de sobrevida / Evolution of children one year post liver transplant

Orthotopic liver transplantation is the only definitive mode of therapy for children with end-stage liver disease. However, it remains challenging because of the necessity to prevent long-term complications. The aim of this study was to analyze the evolution of transplanted patients with more than one year of follow up. Between November 1992 and November 2001, 238 patients underwent 264 liver transplantations. A total of 143 patients with more than one year of follow up were included. The median age of patients +/- SD was 5.41 years +/- 5.26 (r: 0.58-21.7 years). All children received primary immunosuppression with cyclosporine. The indications for liver replacement were: fulminant hepatic failure (n: 50), biliary atresia (n: 38), cirrhosis (n: 37), chronic cholestasis (n: 13) and miscellaneous (n: 5). The indications for liver re-transplantation were: biliary cirrhosis (n: 7), hepatic artery thrombosis (n: 4) and chronic rejection (n: 3). Reduced-size liver allografts were used in 73/157 liver transplants, 14 of them were from living-related donors and 11 were split-livers. Patient and graft survival rates were 93% and 86% respectively. Death risk was statistically higher in retransplanted and reduced-size grafted patients. Growth retardation and low bone density were recovered before the first 3 years post-transplant. The incidence of lymphoproliferative disease was 7.69%. De novo hepatitis B was diagnosed in 7 patients (4.8%). Social risk did not affect the outcome of our population. The prevention, detection and early treatment of complications in the long-term follow up contributed to improve the outcome.

Phenotypic analysis of human BM T-cell depleted by soybean lectin agglutination and E rosetting with sheep RBC: relative enrichment of NK cells and a CD3(+),CD2(-dim) population.

BACKGROUND: T-cell depletion (TCD) of BM allows transplantation across HLA barriers. Although different methods are used throughout the world, the optimal application of TCD still remains unclear, partly due to the lack of thorough analyses of the cellular fractions eliminated or retained in each method, and their possible implications regarding GvHD, GvL, or engraftment. We have analyzed the phenotype of the successive fractions of 19 BM samples depleted by soybean lectin agglutination and sheep erythrocyte rosetting (elimination of T cells that form rosettes through CD2), focusing on the final fraction infused to patients. METHODS: Analysis was performed using three-color flow cytometry and strategies for optimal staining and individualism of the subsets of interest. RESULTS: The relative composition of the lymphoid population varied significantly along the successive steps in TCD: at the agglutination step, B cells and CD4 T cells are greatly reduced, while natural killer cells (NK) and TCRgammadelta+ T are augmented. The rosetting steps imply the relative enrichment of CD2-dim T cells, together with a further rise in the proportion of NK and double-negative T cells frequently TCRgammadelta+. DISCUSSION: The presence of minor subsets of CD2- TCRgammadelta+ and CD2- TCRalphabeta T cells has already been described in the peripheral blood of normal individuals. We report that, by using this method of TCD, CD2-dim T cells, frequently TCRgammadelta+, are retained in the grafts and infused in patients, together with NK cells as the main lymphoid population. We discuss the possible implications of these populations in the biology of the graft, regarding GvHD, GvL and engraftment.

Trasplante hepático. Seguimiento a largo plazo / Liver transplantation. Long term follow up

El trasplante hepático (TH) constituye la única alternativa terapéutica para numerosas enfermedades hepáticas avanzadas. Los adelantos en la técnica quirúrgica y en la inmunosupresión desarrollados en los últimos años permitieron mejorar la sobrevida. En la evolución a largo plazo de los pacientes trasplantados pueden presentarse complicaciones de diversa severidad. Objetivo: analizar la evolución a largo plazo de los pacientes trasplantados con un seguimiento mayor de 1 año post-TH. Material y Métodos: Durante el período 11/92-11/01 se realizaron 264 TH en 238 pacientes. De estos pacientes 143 (157 TH) fueron seguidos más allá de un año post-TH. La mediana de edad (m.a más menos DS) fue de 5,41 años más menos 5,26 (r:0.58 - 21.7 años); 76 pertenecían al sexo femenino. Catorce (9.79 por ciento) recibieron un re-TH. Fueron excluidos los pacientes que no habían cumplido todavía un años post- TH o los que fallecieron antes de ese lapso de seguimiento. Las indicaciones de TH fueron: falla hepática fulminante (FHF) (n:50); atresia de vías biliares (AVB) (n:38); cirrosis (n: 37); colestasis crónica (n: 13) y otras (n: 5). Las indicaciones de Re-TH fueron: cirrosis biliar (n: 7); trombosis de la arteria hepática (n: 4) y rechazo crónico (n: 3). En 73/157 TH se utilizaron injertos reducidos: 14 donantes vivos relacionados (DVR) y 11 biparticiones hepáticas. Se sometieron a análisis estadístico variables potenciales de morbimortalidad. Resultados: La sobrevida global fue: pacientes 93 por ciento: injerto: 86 por ciento. El re-TH y el injerto reducido fueron las variables de mayor significación para aumento del riesgo de muerte en nuestra población. El déficit de talla y masa ósea se recuperó anes de los 3 años post-TH. La incidencia del síndrome linfoproliferativo (SLP) fue del 7.69 por ciento, su diagnóstico y tratamiento temprano permitió una evolución favorable en la mayoria de los casos.

Enfermedad granulomatosa crónica: ¿como reconocerla? / Chronic granulomatous disease: How to recognize it?

Introducción.La emfermedad granulomatosa crónica es un desorden hereditario de la actividad microbicida de los fagocitos originada en una disfunción del complejo enzimático nicotinamida adenina dinucleótido fosfato oxidasa.Hemos analizado las caractéristicas clínicas,evolutivas,microbiológicas y de laboratorio de pacientes pediátricos con diagnóstico de enfermedad granulomatosa crónica en seguimiento por el Servicio de Inmunología del Hospital de PediatríaùProf.DrJ.P Garrahanù.Población,material y métodos.Se analizaron retrospectivamente las historias clínicas de 20 pacientes(18 varones,2 mujeres)con diagnóstico de enfermedad granulomatosa crónica realizado en nuestro establecimiento entre los años 1987 y 1999.Resultados.La edad media de presentación de la primera manifestación clínica fue 2,58 años(rango de 0,42 a 14,25)Las manifestaciones clínicas observadas con mayor frecuencia durante la evolución fueron;infección pulmonar,desnutrición,hepatomegalia,retardo de crecimiento,esplenomegalia y adenopatías superficiales.Los hallazgos de laboratorio más frecuentes fueron:hipergammaglobulinemia,leucocitosis,anemia y velocidad de eritrosedimentación elevada.Los gérmenes preponderantes fueron Aspergillus y staphylococcus.Cinco pacientes presentaron infecciones pulmonares micóticas,4 de ellos con evolución fatal(tres aspergilosis y una infeccioónmixta por scedosporium apiospermum y cladosporium spp)Conclusiones.Observamos una gran demora para establecer el diagnóstico en relación con el inicio de las manifestaciones clínicas.Destacamos el mal pronóstico que genera la infección micótica pulmonar en estos pacientes

[Fungal infections in paediatric patients with chronic granulomatous disease]. / Infecciones fúngicas en pacientes pediátricos con enfermedad granulomatosa crónica.

Chronic granulomatous disease (CGD) is a primary immunodeficiency resulting from a disfunction of microbial capacity of phagocytes. Patients with this disease show great susceptibility to fungal and bacterial infections. Between 1988 and 1998, five paediatric patients with CGD who acquired mycotic infections were studied at the Paediatric Hospital Prof. Dr. J. P. Garrahan and their clinical and microbiological characteristics were described. The fungal infection appeared at the mean-age of 8.3 years (range: 1.1-17 years). All the patients had fever and lung involvement, three of them had suppurative abscesses of soft tissues. The mycological diagnosis was determined by microscopy, culture of clinical samples and serologic tests. There were three cases of disseminated aspergillosis, two cases of mixed infection: one due to Candida albicans and Nocardia asteroides and the other due to Scedosporium apiospermum and Cladosporium spp. Four out of the 5 patients died because of an infections process beyond control. Our conclusion is that new therapeutic measures must be considered along with the study of emerging pathogens in this group of patients.

Lymphoproliferative syndrome with autoimmunity: A possible genetic basis for dominant expression of the clinical manifestations.

Fas (CD95/Apo-1) mutations were previously reported as the genetic defect responsible for human lymphoproliferative syndrome associated with autoimmune manifestations (also known as autoimmune lymphoproliferative syndrome or Canale-Smith syndrome). We have identified 14 new heterozygous Fas mutations. Analysis of patients and families allow us to further dissect this syndrome with regards to the relationship between Fas mutations, inheritance pattern, and phenotype as observed on long-term follow-up. In vitro studies show that lymphocytes from all Fas mutant carriers exhibit a Fas-antibody-induced apoptosis defect. However, among the 8 inherited mutations, 4 of 4 Fas missense mutations were associated with high clinical penetrance, whereas 3 of 4 mutations leading to a truncated Fas product were associated with variable clinical penetrance. This suggests that a second defect, in another yet undefined factor involved in apoptosis and/or lymphoproliferation control, is necessary to induce full clinical expression of the disease. These results also indicate that the currently available antibody-mediated in vitro apoptosis assay does not necessarily reflect the in vivo ability of abnormal Fas molecules to trigger lymphocyte death. In addition, we found that lymphoproliferative manifestations resolved with age, whereas immunological disorders [ie, hypergammaglobulinemia and detection of TcR alphabeta(+) CD4(-) CD8(-) lymphocytes] persisted. This observation suggests that Fas-mediated apoptosis plays a more important role in lymphocyte homeostasis in early childhood than later on in life.

A primary T-cell immunodeficiency associated with defective transmembrane calcium influx.

We investigated a T-cell activation deficiency in a 3-month-old boy with protracted diarrhea, serious cytomegalovirus pneumonia, and a family history (in a brother) of cytomegalovirus infection and toxoplasmosis. In spite of detection of normal number of peripheral lymphocytes, T cells did not proliferate after activation by anti-CD3 and anti-CD2 antibodies, although proliferation induced by antigens was detectable. We sought to determine the origin of this defect as it potentially represented a valuable tool to analyze T-cell physiology. T-cell activation by anti-CD3 antibody or phytohemagglutinin (PHA) led to reduced interleukin-2 (IL-2) production and abnormal nuclear factor-activated T cell (NF-AT; a complex regulating the IL-2 gene transcription) binding activity to a specific oligonucleotide. T-cell proliferation was restored by IL-2. Early events of T-cell activation, such as anti-CD3 antibody-induced cellular protein tyrosine phosphorylation, p59fyn and p56lck kinase activities, and phosphoinositide turnover, were found to be normal. In contrast, anti-CD3 antibody-induced Ca2+ flux was grossly abnormal. Release from endoplasmic reticulum stores was detectable as tested in the presence of anti-CD3 antibody or thapsigargin after cell membrane depolarization in a K+ rich medium, whereas extracellular entry of Ca2+ was defective. The latter abnormality was not secondary to defective K+ channel function, which was found to be normal. A similar defect was found in other hematopoietic cell lineages and in fibroblasts as evaluated by both cytometry and digital video imaging experiments at a single-cell level. This primary T-cell immunodeficiency appears, thus, to be due to defective Ca2+ entry through the plasma membrane. The same abnormality did not alter B-cell proliferation, platelet function, and polymorphonuclear neutrophil (PMN) function. Elucidation of the mechanism underlying this defect would help to understand the physiology of Ca2+ mobilization in T cells.