We aimed to investigate the disease phenotype of Korean pediatric Crohn's disease (CD) patients at diagnosis according to the Paris classification by comparison with patients from the European multicenter 5-years recruitment of children with newly developed IBD (EUROKIDS registry). Korean children and adolescents who had been newly diagnosed with CD at the age of <18 years during 2013-2016 were included in this multicenter retrospective study. Disease phenotype at diagnosis was classified according to the Paris classification, and compared with the published data from the EUROKIDS study. A total of 255 patients were included. The median diagnosis age was 14.7 years (range, 0.8-17.9 years). No significant difference was observed in male-to-female ratio with EUROKIDS (1.9:1 vs. 1.45:1, p=0.062). The proportion of children aged <10 years was significantly lower in Koreans (7.1% vs. 19.6%, p<0.001). Colonic disease was less prominent (10.0% vs. 27.3%, p<0.001), while upper GI involvement was more prominent in Korean children (59.3% vs. 46.2%, p<0.001). The proportion with perianal fistulizing disease at diagnosis was significantly higher in Korean patients (44.8% vs. 8.2%, p<0.001). A separate analysis of Korean patients revealed that perianal fistulizing disease at diagnosis was positively associated with male sex and body mass index z-score (odds ratio [OR]=2.12, 95% confidence interval [CI]=1.20-3.76, p=0.010; and OR=1.29, 95% CI=1.05-1.58, p=0.015, respectively). Approximately half of pediatric CD patients in Korea present with perianal fistulas and/or abscesses at diagnosis, which is a distinct feature of CD in Korean children and adolescents compared to their European counterparts. An underlying genetic difference between ethnicities may play a role in this expression of different phenotypes in pediatric CD.

We aimed to investigate the changes in vitamin D levels and factors associated with vitamin D deficiency (VDD) during the first year of life in Korean preterm infants. We enrolled 333 preterm infants who were born at Kyungpook National University Children’s Hospital between March 2013 and December 2019. 25-hydroxyvitamin D (25-OHD) levels and medical records were collected at birth, 6 months, and 12 months of age. The mean gestational age was 33.4 ± 2.3 weeks and mean 25-OHD levels at birth were 18.2 ± 13.5 ng/mL. The incidence of VDD was 82.8%, 30.6%, and 27.0% at birth, 6 months, and 12 months, respectively. The incidence of severe VDD (25-OHD < 10 ng/mL) was 31.5%, 1.5%, and 0%, at birth, 6 months, and 12 months, respectively. Among infants with severe VDD, the deficiency persisted in 49.6% at 6 months, and 35.3% at 12 months. The strongest predictor of VDD during follow-up was 25-OHD concentration at birth. Vitamin D supplementation at 400 IU/day did not affect vitamin D levels during the first year of life. Therefore, it is important to prevent neonatal VDD through maternal vitamin D supplementation during pregnancy. Further research is needed to determine the optimal vitamin D supplementation dose for Korean preterm infants.

Purpose: To evaluate the incidence rate, clinical characteristics, and perinatal outcomes of pneumothorax in late preterm and full-term newborns with respiratory distress and analyze the risk factors associated with pneumothorax.Methods: Infants born at ≥34 weeks’ gestation with respiratory distress and pneumothorax admitted between February 2014 and December 2020 were enrolled in this study. The pneumothorax group (n=36) was matched to the control group (n=144) in a 1:4 ratio, based on gestational age and birth weight. Risk factors were identified using logistic regression analysis with backward stepwise selection.Results: The incidence of pneumothorax during the study period was 1.36% (38/2,788). All patients were diagnosed with pneumothorax within 48 hours after birth, and increased oxygen demand was the most common symptom. The proportion of mortality and perinatal morbidity, such as intraventricular hemorrhage ≥grade 3, was significantly higher in the pneumothorax group than in the control group. The risk factors associated with pneumothorax were the need for positive pressure ventilation in the delivery room (odds ratio [OR], 3.40; 95% confidence interval [CI], 1.26 to 9.12; P=0.015) and a higher fraction of inspired oxygen to achieve an oxygen saturation of ≥90% on admission (OR, 1.06; 95% CI, 1.03 to 1.09; P<0.001).Conclusion: Pneumothorax should be suspected in late preterm and full-term newborns with respiratory distress within the first 3 days of life. Based on these risk factors, early diagnosis can reduce perinatal mortality and morbidity.

The objectives of this study were 1) to evaluate the effects of vaccination against foot-and-mouth disease (FMD) on growth performance, nutrient digestibility, hematological parameters, and behavior in a ruminant animal and 2) to investigate a possible strategy for reducing its adverse effect. A total of 12 Korean native goats (Capra hircus coreanae; 19.8 ± 2.9 kg) were used in a crossover design with 3 experimental periods and 3 treatments, randomized and balanced for counteracting possible carry-over effects. The treatments were 1) control, 2) co-injection with a commercially available dipyrone (CADI), and 3) supplementation with γ-amino butyric acid (GABA) at 10 g/kg in concentrate mix. Each period lasted 4 wk, and the vaccination against FMD was performed at 2 wk after the start of each period. The goats were individually housed in a metabolic cage and fed ad libitum with a diet consisting of bermuda grass and commercial concentrate mix (6:4, wt/wt). Dry matter intake, ADG, nutrients digestibility, hematological parameters, and behavioral activities of the goats were measured before and after vaccination. Although DMI was not decreased (P > 0.05), ADG was decreased by the vaccination to the goats (P < 0.01). The total number of leukocytes was increased while that of erythrocytes was decreased by the FMD vaccination (P < 0.01). The vaccination shortened standing time while extended lying time and the time spent in drinking (P < 0.05). The treatment by CADI reduced the adverse effect of vaccination on ADG and goat behavior compared with control and GABA treatment (P < 0.05). We concluded that the FMD vaccination decreased ADG of the goats without depression of diet intake, and CADI may attenuate the adverse effect of the FMD vaccination.

We aimed to investigate the correlation between vitamin D status in cord blood and fecal calprotectin concentrations in meconium, and also find their association with intestinal distress symptoms during the first two weeks of life. Two hundred and twenty-eight newborns were enrolled in the study who were delivered at Kyungpook National University Children’s Hospital between July 2016 and August 2017. The first passed meconium samples were collected for fecal calprotectin analysis. Intestinal distress involved infants with necrotizing enterocolitis (NEC) and other feeding interruption signs. The median gestational age of the population was 37.0 (34.3–38.4) weeks, and the median birth weight was 2635 (2100–3268) g. The median fecal calprotectin levels in meconium were 134.1 (55.6–403.2) μg/g (range: 11.5–2000 μg/g) and the median 25-hydroxyvitamin D (25-OHD) concentrations in cord blood were 21.0 (15.5–28.8) ng/mL. Sixty infants (26.3%) had intestinal distress, including four patients (1.8%) diagnosed as having NEC. Higher fecal calprotectin concentrations (398.2 (131.8–900.2) μg/g vs. 105.6 (39.4–248.5) μg/g, p < 0.001) and lower 25-OHD levels (17.9 (12.8–22.1) ng/mL vs. 23.2 (17.2–33.0) ng/mL, p < 0.001) were found in infants with intestinal distress compared to infants without intestinal distress. The cut-off value was set at 359.8 μg/g with a sensitivity of 0.53 and a specificity of 0.82 for the development of intestinal distress in the first two weeks of life. Serum 25-OHD levels in cord blood were inversely correlated with fecal calprotectin concentrations in meconium.

Hydrops fetalis is a condition characterized by excessive fluid accumulation in the fetus, and is classified into immune and non-immune types depending on the underlying disease. Among cases of non-immune hydrops fetalis (NIHF), 15% to 20% are of cardiac origin, and genetic factors such as titin (TTN) gene mutations can contribute to cardiac dysfunction. We report the case of a preterm infant (29+2 weeks, 1,430 g) with hydrops fetalis who developed cardiac tamponade due to major pericardial effusion. Seven hours after birth, the heart rate suddenly decreased, and blood pressure could not be measured. Transthoracic echocardiography revealed substantial pericardial effusion and severely impaired cardiac function, and the preterm infant was diagnosed with pericardial tamponade. Emergency pericardiocentesis was performed, which led to hemodynamic stabilization. Genetic testing identified two heterozygous TTN mutations (c.13898A>T and c.27856G>T), with the latter presumed responsible for the observed cardiac dysfunction. The mother was found to carry the c.13898A>T mutation, but was asymptomatic. This case report highlights the importance of genetic testing in neonates with unexplained NIHF and cardiac complications. Identifying TTN gene mutations provides valuable insights into the underlying pathophysiology and guides clinical management.