Early diagnostic value of the antimycoplasma antibody (IgM) in Mycoplasma pneumoniae pneumonia: A single-center study in 2015

PURPOSE: Recently, the incidence of refractory Mycoplasma pneumoniae (MP) pneumonia has increased in Korea. Given that its early diagnosis is helpful in selection of the treatment, this study aimed at investigating the value of the antimycoplasma antibody (IgM) for early diagnosis of MP pneumonia. METHODS: A total of 315 children admitted with MP pneumonia from September 2015 to May 2016 were investigated with the IgM and polymerase chain reaction (PCR) for the diagnosis of MP pneumonia. Specifically, patients were grouped into nonrefractory respiratory MP and refractory MP groups according to their response to macrolide therapy. RESULTS: In the 44 PCR-negative seroconversed children, seroconversed IgM was more frequent in the refractory MP group compared with the nonrefractory respiratory MP group with statistical significance (P<0.001). In the 264 IgM-positive children, the time of antibody reaction was more delayed in the refractory MP group compared to the nonrefractory respiratory MP group with statistical significance (P<0.001). CONCLUSION: This study showed that there was a higher incidence of seroconversed IgM and delayed antibody reaction in the refractory MP group. In children with suspect MP pneumonia, follow-up studies of antibody are necessary, even through initial antibody and PCR showed negative findings. In addition, this result may suggest that the diagnosis of refractory MP pneunomia will be helpful in establishing the strategy of the treatment.

Secular change in waist circumference and waist-height ratio and optimal cutoff of waist-height ratio for abdominal obesity among Korean children and adolescents over 10 years / 소아과

PURPOSE: This study aimed to evaluate the time trends of waist circumference (WC) and waist-height ratio (WHR), and to present WC and WHR distributions with optimal WHR cutoff for abdominal obesity in Korean children and adolescents. METHODS: We performed a retrospective cross-sectional analysis of data from 13,257 children and adolescents (6,987 boys and 6,270 girls) aged 6–18 years who were included in the third to sixth Korea National Health and Nutrition Examination Survey (KNHANES, 2005–2015). Linear regression analyses were used to identify secular changes in WC and WHR by age, sex, and KNHANES waves. A receiver operating characteristic curve analysis was used to determine the optimal WHR cutoff values for abdominal obesity and cardiometabolic risk factors. RESULTS: The mean WC and WHR distributions from 2005 to 2015 showed no significant secular changes between the KNHANES 4 waves (P for trend ≥0.05 in all ages and both sexes). The mean WCs in the present study were lower than those in the 2007 Korean National Growth Charts. The mean WHR at ages <13 years was statistically higher in the boys than in the girls, but did not significantly differ between the sexes among those aged 13 to 18 years. The optimal WHR cutoff for abdominal obesity was 0.48 (area under the curve, 0.985; 95% confidence interval, 0.985–0.985) in the 13- to 18-year-old adolescents. CONCLUSION: WC and WHR showed no secular changes over 10 years. The optimal WHR cutoff for abdominal obesity of 0.48 is useful for diagnosing and managing obesity and thus preventing obesity-related cardiometabolic complications in 13- to 18-year-old Korean adolescents.

Comparing adult height gain and menarcheal age between girls with central precocious puberty treated with gonadotropin-releasing hormone agonist alone and those treated with combined growth hormone therapy

PURPOSE: This study aimed to investigate the outcomes of gonadotropin-releasing hormone agonist (GnRHa) therapy with or without growth hormone (GH) therapy for girls with idiopathic central precocious puberty (CPP). METHODS: The medical records of 166 girls diagnosed with CPP from 2002 to 2017 were retrospectively reviewed. All included patients were treated with GnRHa for ≥36 months. Changes in height standard deviation score (SDS) for bone age, chronological age (CA), and predicted adult height (PAH) were assessed for the first three years of treatment. The final height gain SDS was calculated as the difference between the initial PAH SDS and adult height (AH) SDS; these were then compared between the GnRHa group (group A, n=135) and the combined GnRHa/GH group (group B, n=31).

Clinical difference between single infection and coinfection with respiratory virus: The 2014 single-center study

PURPOSE: We investigated the clinical difference between single infection and coinfection with respiratory virus in hospitalized children with acute respiratory tract infections. METHODS: We reviewed 727 patients who were admitted with the diagnosis of acute respiratory infection at the Department of Pediatrics, Bundang Jesaeng Hospital between January and December of 2014. Diagnoses were made using the multiplex reverse transcriptase polymerase chain reaction (RT-PCR) assay targeting 16 viruses in nasopharyngeal swabs. Subjects were classified as the single virus infection and coinfection groups. RESULTS: A total of 439 patients were enrolled; 359 (77.2%) under 24 months. Single virus was detected in 279 (63.6%). Coinfection with multiple virus was detected in 160 (36.4%): 126 (28.7%) with 2 viruses, 30 (6.8%), and 4 (0.9%) with 3 to 4 viruses. Viral coinfection was detected in 28 samples (17.5%), with respiratory syncytial virus (RSV) A and rhinovirus being the most dominating combination. There were no clinical differences between the single infection and coinfection groups, except sputum and the frequency of high RSV load. Sputum was significantly more frequent in the coinfection group (P=0.043), and the frequency of high RSV load was significantly higher in the single infection group (P=0.029). Disease severity (high fever, the duration of fever [≥5 days], and the length of hospital stay [≥5 days], O₂ therapy) did not differ significantly between both groups. RSV was a frequent virus of single infection during winter. Coinfection was most common in winter. CONCLUSION: There were no clinical differences between single infection and coinfection, except sputum and the frequency of high RSV load.

Factors associated with obesity of acute bronchiolitis in infants: association of obesity with disease severity

PURPOSE: Both under-nutrition and obesity may be associated with severity of viral infection. We investigated the association of obesity with clinical factors and the severity of acute bronchiolitis in infants. METHODS: We reviewed 740 infants younger than 1 year of age who were admitted with the first episode of acute bronchiolitis between 2010 and 2013. Subjects were classified into 3 groups according to the weight-for-length Z-score. RESULTS: Younger age (3.6+/-2.6 months) was more frequent in the obesity group (P<0.001). Infants aged < or =6 months (90%) dominantly included in the obesity group. Logistic regression showed that age (younger than 3 months) was independently associated with the overweight and obesity groups with acute bronchiolitis in infants (odds ratio [OR], 1.77; P=0.001 for overweight; OR, 4.67; P<0.001 for obesity). Moreover, the obesity group was associated with an increased risk of chest retraction, hypoxia, respiratory syncytial virus detection, length of stay (more than 5 days), and need for oxygen supplement. These factors tended to increase from the overweight group toward the obesity group. CONCLUSION: Younger than 3 months of age was a risk factor for developing worse clinical course in overweight and obesity groups with acute bronchiolitis in infants. Careful attention should be paid to the clinical course of younger obese infants with acute bronchiolitis.