Objective: This study aimed to correlate the genetic profile of the NUDT15 and TPMT genes with the side effects of the treatment of pediatric patients with acute lymphoid leukemia who were undergoing maintenance therapy at a tertiary care hospital in 2017. Methods: This was an analytical, longitudinal, observational study in which the genotypes of the genes of interest were determined by PCR allelic discrimination with TaqMan® probes in patients receiving chemotherapy during the maintenance phase in the Pediatric Hematology and Oncology Unit in 2017. Sociodemographic and clinical data corresponding to the first six months of their maintenance chemotherapy were collected, and the correlation between the genotypes obtained and the development of side effects during the maintenance phase of chemotherapy in these patients was evaluated. Results: Seventy pediatric patients were included in the study. Genetic analyses were carried out of these for NUDT15 and TPMT (rs1800462 and rs1800460) on 68 patients, while for the rs1142345 polymorphism, typing was achieved in 42 patients. 4/68 patients were heterozygous for NUDT15, and the same number of patients were heterozygous for rs1800462 and rs1142345, while for rs1800460, 6 heterozygous patients were identified. No statistically significant association was identified between the genetic variants and the outcomes of interest. Conclusion: Studies with a larger population size are needed and the evaluation of other genetic variants that may influence the development of side effects during maintenance chemotherapy.

El estudio del nódulo pulmonar en pediatría es un desafío diagnóstico, se debe tener en cuenta diferentes patologías, especialmente infecciones. En países en desarrollo, donde la infección por tuberculosis es endémica, es uno de los diagnósticos más probables; sin embargo, las neoplasias como posibilidad diagnóstica no deben desestimarse.Objetivo: Describir el caso clínico de una paciente con un nódulo pulmonar en quien después de descartar las causas más frecuentes se diagnosticó una malignidad pulmonar primaria.Caso Clínico: Adolescente de 17 años, consultó por cuadro de un mes de evolución de tos, disnea y hemoptisis sin otros síntomas asociados, sin respuesta a terapias antibióticas habituales, por lo que se realizó una tomografía de tórax contrastada donde se evidenció un nódulo pulmonar en lóbulo inferior derecho de características irregulares, se descartó un proceso infeccioso por estudios de lavado bronco-alveolar (para tuberculosis, hongos y otras bacterias) y se completó estudio con biopsia, que fue compatible con carcinoma mucoepidermoide. Fue operada con lobectomía de lóbulo inferior derecho con vaciamiento ganglionar con respuesta clínica adecuada a tres años de seguimiento.Conclusión: El nódulo pulmonar en pediatría es un hallazgo que se asocia especialmente a infección, sin embargo, se debe tener en cuenta condiciones neoplásicas, no solo metástasis sino también lesiones malignas primarias del pulmón por las implicaciones en el pronóstico.

RATIONALE: Small airway (bronchioles less than 2 mm in diameter) means less than 10% of total airway resistance. In despite of it is not commonly used at clinical practice because its variability, its dysfunction has been closely linked with severity of asthma (both with symptoms and with respiratory tests). METHODS:We have done an observational retrospective study to evaluate the relationship between small airways dysfunction and bronchial hyperresponsiveness (BHR). We studied the small airway in 70 spirometries and the presence or not of BHR through methacholine provocations. We analyzed them with Student T-Test. RESULTS: There was no difference in sex or age. The patients without BHR have a forced expiratory volume in one-second (FEV1) value statistically superior to patients with BHR (3.35vs2.93, p50.02). In the same way, the values of forced expiratory flow at 75% (FEF75%) and at 50% (FEF50%) of the vital capacity, are statistically lower in patients with BHR: FEF 75% 6.93vs5.51, p50.004; FEF 50% 4.18vs3.25, p50.00. The smallest airway, FEF25% has not shown difference statistically significant between the groups: 1.890vs1.385, p50.09. No correlation was found between the patients who also have rhinitis symptoms, p 5 0.88. Neither it was a difference with other markers, such as fraction of exhaled nitric oxide, FENO (p50.15). CONCLUSIONS: Increasing evidence shows the relationship between the small airways and the clinical expression and severity of asthma. This study concludes the importance of small airway to predict bronchial hyperresponsiveness especially FEF75% and FEF50%. A better understanding of the role small airways is playing in asthma is needed.

of (South). RATIONALE: Post-infectious bronchiolitis obliterans (PIBO) is an irreversible form of chronic obstructive lung disease secondary to severe lower respiratory infection (LRI). The children who had PIBO during infancy usually show recurrent wheezing and frequent exacerbations due to respiratory infection. We followed them and examined their clinical characteristics, airway hyperresponsiveness, and lung function parameters. METHODS: Forty-one patients diagnosed with PIBO before 3 years of age were enrolled. Diagnosis of PIBO was made according to the previously described criteria: 1) history of acute LRI in previously healthy children 2) unresolved respiratory symptoms associated with airway obstruction (cough, shortness of breath on exertion and/or abnormal breath sounds) that last for more than 6 weeks after the initial episode despite treatment 3) mosaic perfusion with air trapping, bronchiectasis, or atelectasis on pulmonary HRCT. Spirometry and methacholine challenge test were performed in these children at 6 years of age and lung function parameters were compared with age-matched control values using Z score. RESULTS: Mean onset age of PIBO was 21.8 months. Mean follow-up period was 61.1 months. PIBO patients showed significantly lower FEV 1 and FEF 25-75% Z scores compared with age-matched control values. Bronchial hyperresponsiveness was observed in more than 40% of PIBO patients and it was not related with the atopic status of the patients. CONCLUSIONS: In our study, the children who had PIBO during infancy had reduced lung function parameters and many of them showed bronchial hyperresponsiveness. Our study suggests that PIBO during early infancy might cause persistent lung function impairment. Abstracts AB217MONDAY