Gastrointestinal tract and liver graft-versus-host disease in pediatric patients with hematopoietic progenitor cell transplantation at a tertiary care center in Mexico. / Enfermedad injerto contra huésped gastrointestinal y hepático en pacientes pediátricos con trasplante de células progenitoras hematopoyéticas en el Hospital Infantil de México Federico Gómez.

INTRODUCTION AND AIMS: Graft-versus-host disease (GVHD) is a common multisystemic complication of allogeneic hematopoietic cell transplantation. The most frequent presentations of graft-versus-host disease involve the skin, the gastrointestinal tract, and the liver. The aim of the present study was to know the frequency of gastrointestinal tract and liver GVHD and the characteristics of disease presentation in pediatric patients that underwent hematopoietic stem cell transplantation (HSCT) at a tertiary care hospital center in Mexico City. MATERIAL AND METHODS: A retrospective study was carried out, utilizing the case records of patients that underwent HSCT in 2015, to determine the frequency of GVHD in pediatric patients at a Mexican tertiary care hospital center. RESULTS: In 2015, 16 HSCT were performed, 11 of which were carried out in males (68%). Only 3 patients developed graft-versus-host disease (18.7%). One patient presented with skin and liver GVHD and 2 patients presented with gastrointestinal tract and liver GVHD, which was the most frequent type. CONCLUSIONS: HSCT is still an uncommon procedure in Mexico and there is a lower frequency of gastrointestinal tract and liver GVHD than that reported in other studies. Most certainly, there will be an increase in this type of patient and risk factors in the Mexican population must still be determined to help predict the onset of GVHD.

Illumina next generation sequencing data and expression microarrays data from retinoblastoma and medulloblastoma tissues.

Retinoblastoma (Rb) is a pediatric intraocular malignancy and probably the most robust clinical model on which genetic predisposition to develop cancer has been demonstrated. Since deletions in chromosome 13 have been described in this tumor, we performed next generation sequencing to test whether recurrent losses could be detected in low coverage data. We used Illumina platform for 13 tumor tissue samples: two pools of 4 retinoblastoma cases each and one pool of 5 medulloblastoma cases (raw data can be found at http://www.ebi.ac.uk/ena/data/view/PRJEB6630). We first created an in silico reference profile generated from a human sequenced genome (GRCh37p5). From this data we calculated an integrity score to get an overview of gains and losses in all chromosomes; we next analyzed each chromosome in windows of 40 kb length, calculating for each window the log2 ratio between reads from tumor pool and in silico reference. Finally we generated panoramic maps with all the windows whether lost or gained along each chromosome associated to its cytogenetic bands to facilitate interpretation. Expression microarrays was done for the same samples and a list of over and under expressed genes is presented here. For this detection a significance analysis was done and a log2 fold change was chosen as significant (raw data can be found at http://www.ncbi.nlm.nih.gov/geo/accession number GSE11488). The complete research article can be found at Cancer Genetics journal (Garcia-Chequer et al., in press) [1]. In summary here we provide an overview with visual graphics of gains and losses chromosome by chromosome in retinoblastoma and medulloblastoma, also the integrity score analysis and a list of genes with relevant expression associated. This material can be useful to researchers that may want to explore gains and losses in other malignant tumors with this approach or compare their data with retinoblastoma.

Overview of recurrent chromosomal losses in retinoblastoma detected by low coverage next generation sequencing.

Genes are frequently lost or gained in malignant tumors and the analysis of these changes can be informative about the underlying tumor biology. Retinoblastoma is a pediatric intraocular malignancy, and since deletions in chromosome 13 have been described in this tumor, we performed genome wide sequencing with the Illumina platform to test whether recurrent losses could be detected in low coverage data from DNA pools of Rb cases. An in silico reference profile for each pool was created from the human genome sequence GRCh37p5; a chromosome integrity score and a graphics 40 Kb window analysis approach, allowed us to identify with high resolution previously reported non random recurrent losses in all chromosomes of these tumors. We also found a pattern of gains and losses associated to clear and dark cytogenetic bands respectively. We further analyze a pool of medulloblastoma and found a more stable genomic profile and previously reported losses in this tumor. This approach facilitates identification of recurrent deletions from many patients that may be biological relevant for tumor development.

[Central nervous system pathology in children with AIDS]. / Patología del sistema nervioso central en niños con síndrome de inmunodeficiencia adquirida.

The neuropathological manifestations of AIDS in children vary widely and includes, among others: cerebral atrophy, basal ganglia calcification, corticospinal tract demyelinization, and HIV encephalomyelitis with multinucleated cells. The purpose of this work is to inform the postmortem CNS findings in 14 pediatric AIDS patients which were studied from January 1986 to February 1992, at the Hospital Infantil de México Federico Gómez. Basal ganglia vascular calcification, HIV multinucleated cells, and corticospinal tract demyelinization, were significantly less frequent (P < 0.01) in our patients than those informed in the literature. Opportunistic CNS infections found in our patients were produced by microorganisms commonly described in adults. We think that these differences may be explained because the majority of our patients acquired the infection trough blood transfusion at an age in which the CNS is fully developed. The pattern of HIV transmission in our country has been changing recently with an increase in the number of perinatal cases. We also think that in the near future we will observe a change in the neuropathological findings of our pediatric AIDS population.

[Coronary arteriopathy associated with cardiomyopathy in an adolescent with AIDS]. / Arteriopatía coronaria asociada a cardiomiopatía en un adolescente con síndrome de inmunodeficiencia adquirida.

The purpose of this paper is to inform the case of a 15 years old male patient who died as a consequence of acquired immunodeficiency syndrome (AIDS) complications. The postmortem examination showed a coronary lesion which, to the best of our knowledge, has not been previously described. This vasculopathy was restricted to the coronary arteries; myocardial changes similar to those described in AIDS-associated dilated cardiomyopathy were also present. The coronariopathy was indistinguishable from that described in the blood vessels of the brain in patients with AIDS-related cerebral arteriopathy. We also reviewed the autopsy material from another 14 children who died of AIDS, an in none of them exhibited similar changes in the coronary arteries. In addition we present the clinical findings and some theoretical considerations regarding the pathogenesis of the lesions.

[Kawasaki disease in Mexican children]. / Enfermedad de Kawasaki en niños mexicanos.

The records of 16 cases seen at Mexico Children's Hospital with a diagnosis of KD were reviewed. Mean age was three years; eight were infants, and males were dominant with a ratio of 4.3:1. Two cases occurred in sibling. Evidence of myocarditis was recognized in six, and 12 had coronary anomalies, including five with aneurysms. Two infants with severe coronary disease died, one suddenly with myocardial ischemia, and one with a ruptured aortic aneurysm. Another infant developed severe stenosis of the right coronary artery but remains asymptomatic. Two cases have persistent coronary ectasia and seven are asymptomatic with a normal echocardiogram. Predictors of coronary risk were correlated with clinical outcome. All six cases with 6 or more points had coronary anomalies, two developed giant aneurysms, two died and one has severe coronary stenosis. Of 10 cases with less than 6 points, four did not have coronary involvement, none developed giant aneurysms and none died nor developed severe coronary sequelae. Although KD has been sporadically reported in this country, the present series, the largest from a single institution, firmly establishes the presence of the disease in Mexico.

[Actinomycosis of the bladder in a girl]. / Actinomicosis vesical en una niña.

Abdominal actinomycosis is a rare finding in pediatric patients and its location in the urinary bladder is exceptional. On the other hand, immunodepression can be found in several disorders including that of actinomycosis. The purpose of this study was to report a case of urinary bladder actinomycosis seen in a seven year old girl. No risk factors were found. It was diagnosed as an abdominal tumor which was successfully surgically removed and treated with penicillin. During her recovery, she suffered from a transitory cell-mediated depression of her immune system which later returned to normal once treatment as installed. The pathogenesis of actinomycosis is presented and a review of the literature is cited. Actinomycosis; immunodepression; bladder.