Exercise Frequency Reduction Is Associated With Higher Risk of Infection in Newly Diagnosed Diabetes: A Nationally Representative Cohort Study

Background@#Exercise is an important method to control the progression of diabetes. Since diabetes compromises immune function and increases the risk of infectious diseases, we hypothesized that exercise may affect the risk of infection by its immunoprotective effects.However, population-based cohort studies regarding the association between exercise and the risk of infection are limited, especially regarding changes in exercise frequency. The aim of this study was to determine the association between the change in exercise frequency and the risk of infection among patients with newly diagnosed diabetes. @*Methods@#Data of 10,023 patients with newly diagnosed diabetes were extracted from the Korean National Health Insurance Service-Health Screening Cohort. Self-reported questionnaires for moderate-to-vigorous physical activity (MVPA) were used to classify changes in exercise frequency between two consecutive two-year periods of health screenings (2009–2010 and 2011–2012). The association between changes in exercise frequency and the risk of infection was evaluated using multivariable Cox proportional-hazards regression. @*Results@#Compared with engaging in ≥ 5 times of MVPA/week during both periods, a radical decrease in MVPA (from ≥ 5 times of MVPA/week to physical inactivity) was associated with a higher risk of pneumonia (adjusted hazard ratio [aHR], 1.60; 95% confidence interval [CI], 1.03–2.48) and upper respiratory tract infection (aHR, 1.15; 95% CI, 1.01–1.31). In addition, a reduction of MVPA from ≥ 5 to < 5 times of MVPA/week was associated with a higher risk of pneumonia (aHR, 1.52; 95% CI, 1.02–2.27), whereas the risk of upper respiratory tract infection was not higher. @*Conclusion@#Among patients with newly diagnosed diabetes, a reduction in exercise frequency was related to an increase in the risk of pneumonia. For patients with diabetes, a modest level of physical activity may need to be maintained to reduce the risk of pneumonia.

Psychopathologic Profiles and Clusters in Tertiary Clinic Referred Patients with Adult Attention Deficit Hyperactivity Disorder: A Person-Centered Analysis

Objective@#Adult attention deficit hyperactivity disorder (ADHD) has a heterogeneous clinical presentation with patients showing very frequent emotional problems. In the present study, patients with adult ADHD were subtyped based on their psychopathology using a person-centered approach. @*Methods@#In the present chart review study, detailed findings of psychological evaluation conducted as part of routine care were utilized. A total of 77 subjects with adult ADHD were included in the analysis. Detailed ADHD symptoms, psychiatric comorbid Diagnostic and Statistical Manual of Mental Disorders (DSM) diagnoses, and severity of mood and anxiety symptoms were evaluated in the person-centered analysis. @*Results@#Three clusters were generated using clustering analysis. DSM comorbid conditions did not significantly impact the clustering. Cluster 1 consisted of ADHD combined presentation (ADHD-C) with less mood symptoms, cluster 2 of ADHD predominantly inattentive presentation and cluster 3 of ADHD-C with significant mood symptoms. Patients in cluster 3 had adulthood functional impairment more frequently compared with patients in cluster 1. Patients in cluster 3 showed recurrent thoughts of death and suicidal ideation more frequently compared with patients in cluster 1. @*Conclusion@#Further studies are needed to confirm the relationships observed in the present study.

High Level of Real Urban Air Pollution Promotes Cardiac Arrhythmia in Healthy Mice

Background and Objectives@#Ambient particulate matter (PM) in real urban air pollution (RUA) is an environmental health risk factor associated with increased cardiac events. This study investigated the threshold level to induce arrhythmia, as well as arrhythmogenic mechanism of RUA that mainly consisted of PM <2.5 μm in aerodynamic diameter close to ultrafine particles. @*Methods@#RUA was artificially produced by a lately developed pyrolysis based RUA generator.C57BL/6 mice were divided into 4 groups: a control group (control, n=12) and three groups with exposure to RUA with the concentration of 200 µg/㎥ (n=12), 400 µg/㎥ (n=12), and 800 µg/㎥ (n=12). Mice were exposed to RUA at each concentration for 8 hr/day and 5 day/week to mimic ordinary human activity during 3 weeks. @*Results@#The QRS and QTc intervals, as well as intracellular Ca2+ duration, apicobasal action potential duration (APD) gradient, fibrosis, and inflammation of left ventricle of mouse hearts were increased dose-dependently with the increase of RUA concentration, and significantly increased at RUA concentration of 400 µg/㎥ compared to control (all p<0.001). In mice exposed to RUA concentration of 800 µg/㎥ , spontaneous ventricular arrhythmia was observed in 42%, with significant increase of inflammatory markers, phosphorylated Ca2+ /calmodulindependent protein kinase II (CaMKII), and phospholamban (PLB) compared to control. @*Conclusions@#RUA could induce electrophysiological changes such as APD and QT prolongation, fibrosis, and inflammation dose-dependently, with significant increase of ventricular arrhythmia at the concentration of 400 µg/㎥ . RUA concentration of 800 µg/㎥ increased phosphorylation of CaMKII and PLB.

Psychopathologic Profiles and Clusters in Tertiary Clinic Referred Patients with Adult Attention Deficit Hyperactivity Disorder: A Person-Centered Analysis

Objective@#Adult attention deficit hyperactivity disorder (ADHD) has a heterogeneous clinical presentation with patients showing very frequent emotional problems. In the present study, patients with adult ADHD were subtyped based on their psychopathology using a person-centered approach. @*Methods@#In the present chart review study, detailed findings of psychological evaluation conducted as part of routine care were utilized. A total of 77 subjects with adult ADHD were included in the analysis. Detailed ADHD symptoms, psychiatric comorbid Diagnostic and Statistical Manual of Mental Disorders (DSM) diagnoses, and severity of mood and anxiety symptoms were evaluated in the person-centered analysis. @*Results@#Three clusters were generated using clustering analysis. DSM comorbid conditions did not significantly impact the clustering. Cluster 1 consisted of ADHD combined presentation (ADHD-C) with less mood symptoms, cluster 2 of ADHD predominantly inattentive presentation and cluster 3 of ADHD-C with significant mood symptoms. Patients in cluster 3 had adulthood functional impairment more frequently compared with patients in cluster 1. Patients in cluster 3 showed recurrent thoughts of death and suicidal ideation more frequently compared with patients in cluster 1. @*Conclusion@#Further studies are needed to confirm the relationships observed in the present study.

High Level of Real Urban Air Pollution Promotes Cardiac Arrhythmia in Healthy Mice

Background and Objectives@#Ambient particulate matter (PM) in real urban air pollution (RUA) is an environmental health risk factor associated with increased cardiac events. This study investigated the threshold level to induce arrhythmia, as well as arrhythmogenic mechanism of RUA that mainly consisted of PM <2.5 μm in aerodynamic diameter close to ultrafine particles. @*Methods@#RUA was artificially produced by a lately developed pyrolysis based RUA generator.C57BL/6 mice were divided into 4 groups: a control group (control, n=12) and three groups with exposure to RUA with the concentration of 200 µg/㎥ (n=12), 400 µg/㎥ (n=12), and 800 µg/㎥ (n=12). Mice were exposed to RUA at each concentration for 8 hr/day and 5 day/week to mimic ordinary human activity during 3 weeks. @*Results@#The QRS and QTc intervals, as well as intracellular Ca2+ duration, apicobasal action potential duration (APD) gradient, fibrosis, and inflammation of left ventricle of mouse hearts were increased dose-dependently with the increase of RUA concentration, and significantly increased at RUA concentration of 400 µg/㎥ compared to control (all p<0.001). In mice exposed to RUA concentration of 800 µg/㎥ , spontaneous ventricular arrhythmia was observed in 42%, with significant increase of inflammatory markers, phosphorylated Ca2+ /calmodulindependent protein kinase II (CaMKII), and phospholamban (PLB) compared to control. @*Conclusions@#RUA could induce electrophysiological changes such as APD and QT prolongation, fibrosis, and inflammation dose-dependently, with significant increase of ventricular arrhythmia at the concentration of 400 µg/㎥ . RUA concentration of 800 µg/㎥ increased phosphorylation of CaMKII and PLB.

A Case of Anti-Le(bH) Antibody Identified in a Patient with Ulcerative Colitis

A 67-year-old man previously diagnosed with ulcerative colitis complained of difficulty in defecation and underwent balloon dilatation of rectum, but the procedure failed. The patient was transferred to a surgical department for further treatment. Before surgery, his red cells were typed A, Rh(D) positive. The antibody screening test was positive and the results of the identification tests were atypical. The reactivity was similar to anti-Le(b) antibody; however, the antibody showed panreactivity against papainized red cells. It showed stronger reactivity against O red cells than A Le(a−b+) red cells, and we concluded that the antibody was anti-Le(bH). After reexamination, his Lewis phenotype was found to be Le(a−b−). His FUT2 and FUT3 were analyzed to confirm his Lewis blood type, and c.59T>G and c.1067T>A variants were found on the FUT3. Therefore, the patient's Lewis blood type was concluded as Le(a−b−).

Cognitive Function, Emotional and Behavioral Problems, and Temperament of Premature Children

OBJECTIVES: We aimed to compare preterm, neurodevelopmentally disordered and healthy full-term children. METHODS: We enrolled 47 children who were born preterm, 40 neurodevelopmentally disordered children, and 80 healthy children as control participants, in order to assess the cognitive functioning and the risk of behavioral problems at the age of 5. Children were assessed using the Korean Wechsler Preschool and Primary Scale of Intelligence-4th edition (K-WPPSI-IV), the Child Behavior Checklist (CBCL), and the Temperament and Character Inventory (TCI). RESULTS: The mean K-WPPSI-IV score of the preterm group was 87.19±17.36, which was significantly higher than that of the neurodevelopmental disorder group (69.98±28.63; p < 0.001) but lower than that of the control group (107.74±14.21; p < 0.001). The cumulative CBCL scores of the preterm children were not significantly different from those of the control group. Additionally, the TCI scores for reward dependence of the preterm children were higher than those of the control group. CONCLUSION: The cognitive performance of preterm infants was lower than that of healthy full-term infants at the age of 5, and there was an association between slower growth and decreased cognitive ability.

The First Case of Para-Bombay Blood Type Encountered in a Korean Tertiary Hospital

Para-Bombay phenotypes are rare blood groups that have inherent defects in producing H antigens associated with FUT1 and/or FUT2. We report the first case of para-Bombay blood type in a Southeast Asian patient admitted at a tertiary hospital in Korea. A 23-year-old Indonesian man presented to the hospital with fever and was diagnosed with a disseminated nontuberculous mycobacterium infection and anemia. During blood group typing for blood transfusion, cell typing showed no agglutination with both anti-A and anti-B reagents. Serum typing showed strong reactivity against B cells and trace agglutination pattern with A1 cells. His red blood cells failed to react with anti-H reagents. Direct sequencing of FUT1 and FUT2 revealed a missense variation, c.328G>A (p.Ala110Thr, rs56342683, FUT1*01W.02), and a synonymous variant, c.390C>T (p.Asn130=, rs281377, Se³⁵⁷), respectively. This highlights the need for both forward and reverse grouping.

Analgesic Effect of Toll-like Receptor 4 Antagonistic Peptide 2 on Mechanical Allodynia Induced with Spinal Nerve Ligation in Rats

Neuroinflammation is one of the key mechanisms of neuropathic pain, which is primarily mediated by the Toll-like receptor 4 (TLR4) signaling pathways in microglia. Therefore, TLR4 may be a reasonable target for treatment of neuropathic pain. Here, we examined the analgesic effect of TLR4 antagonistic peptide 2 (TAP2) on neuropathic pain induced by spinal nerve ligation in rats. When lipopolysaccharide (LPS)-stimulated BV2 microglia cells were treated with TAP2 (10 µM), the mRNA levels of proinflammatory mediators, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS), were markedly decreased by 54–83% as determined by quantitative PCR (qPCR) analysis. Furthermore, when TAP2 (25 nmol in 20 µL PBS) was intrathecally administered to the spinal nerve ligation-induced rats on day 3 after surgery, the mechanical allodynia was markedly decreased for approximately 2 weeks in von Frey filament tests, with a reduction in microglial activation. On immunohistochemical and qPCR analyses, both the level of reactive oxygen species and the gene expression of the proinflammatory mediators, such as TNF-α, IL-1β, IL-6, COX-2, and iNOS, were significantly decreased in the ipsilateral spinal dorsal horn. Finally, the analgesic effect of TAP2 was reproduced in rats with monoiodoacetate-induced osteoarthritic pain. The findings of the present study suggest that TAP2 efficiently mitigates neuropathic pain behavior by suppressing microglial activation, followed by downregulation of neuropathic pain-related factors, such as reactive oxygen species and proinflammatory molecules. Therefore, it may be useful as a new analgesic for treatment of neuropathic pain.

Prediction of itching diagnostic marker through RNA sequencing of contact hypersensitivity and skin scratching stimulation mice models

Pruritus (itching) is classically defined as an unpleasant cutaneous sensation that leads to scratching behavior. Although the scientific criteria of classification for pruritic diseases are not clear, it can be divided as acute or chronic by duration of symptoms. In this study, we investigated whether skin injury caused by chemical (contact hypersensitivity, CHS) or physical (skin-scratching stimulation, SSS) stimuli causes initial pruritus and analyzed gene expression profiles systemically to determine how changes in skin gene expression in the affected area are related to itching. In both CHS and SSS, we ranked the Gene Ontology Biological Process terms that are generally associated with changes. The factors associated with upregulation were keratinization, inflammatory response and neutrophil chemotaxis. The Kyoto Encyclopedia of Genes and Genomes pathway shows the difference of immune system, cell growth and death, signaling molecules and interactions, and signal transduction pathways. Il1a , Il1b and Il22 were upregulated in the CHS, and Tnf, Tnfrsf1b, Il1b, Il1r1 and Il6 were upregulated in the SSS. Trpc1 channel genes were observed in representative itching-related candidate genes. By comparing and analyzing RNA-sequencing data obtained from the skin tissue of each animal model in these characteristic stages, it is possible to find useful diagnostic markers for the treatment of itching, to diagnose itching causes and to apply customized treatment.

Extracellular Vesicles Derived from Hypoxic Human Mesenchymal Stem Cells Attenuate GSK3β Expression via miRNA-26a in an Ischemia-Reperfusion Injury Model

PURPOSE: Bioactive molecules critical to intracellular signaling are contained in extracellular vesicles (EVs) and have cardioprotective effects in ischemia/reperfusion (IR) injured hearts. This study investigated the mechanism of the cardioprotective effects of EVs derived from hypoxia-preconditioned human mesenchymal stem cells (MSCs). MATERIALS AND METHODS: EV solutions (0.4 µg/µL) derived from normoxia-preconditioned MSCs (EVNM) and hypoxia-preconditioned MSCs (EVHM) were delivered in a rat IR injury model. Successful EV delivery was confirmed by the detection of PKH26 staining in hearts from EV-treated rats. RESULTS: EVHM significantly reduced infarct size (24±2% vs. 8±1%, p < 0.001), and diminished arrhythmias by recovering electrical conduction, INa current, and Cx43 expression. EVHM also reversed reductions in Wnt1 and β-catenin levels and increases in GSK3β induced after IR injury. miRNA-26a was significantly increased in EVHM, compared with EVNM, in real-time PCR. Finally, in in vitro experiments, hypoxia-induced increases in GSK3β expression were significantly reduced by the overexpression of miRNA-26a. CONCLUSION: EVHM reduced IR injury by suppressing GSK3β expression via miRNA-26a and increased Cx43 expression. These findings suggest that the beneficial effect of EVHM is related with Wnt signaling pathway.

The Role of Serotonin in Ventricular Repolarization in Pregnant Mice

PURPOSE: The mechanisms underlying repolarization abnormalities during pregnancy are not fully understood. Although maternal serotonin (5-hydroxytryptamine, 5-HT) production is an important determinant for normal fetal development in mice, its role in mothers remains unclear. We evaluated the role of serotonin in ventricular repolarization in mice hearts via 5Htr3 receptor (Htr3a) and investigated the mechanism of QT-prolongation during pregnancy. MATERIALS AND METHODS: We measured current amplitudes and the expression levels of voltage-gated K⁺ (Kv) channels in freshly-isolated left ventricular myocytes from wild-type non-pregnant (WT-NP), late-pregnant (WT-LP), and non-pregnant Htr3a homozygous knockout mice (Htr3a(−/−)-NP). RESULTS: During pregnancy, serotonin and tryptophan hydroxylase 1, a rate-limiting enzyme for the synthesis of serotonin, were markedly increased in hearts and serum. Serotonin increased Kv current densities concomitant with the shortening of the QT interval in WT-NP mice, but not in WT-LP and Htr3a(−/−)-NP mice. Ondansetron, an Htr3 antagonist, decreased Kv currents in WT-LP mice, but not in WT-NP mice. Kv4.3 directly interacted with Htr3a, and this binding was facilitated by serotonin. Serotonin increased the trafficking of Kv4.3 channels to the cellular membrane in WT-NP. CONCLUSION: Serotonin increases repolarizing currents by augmenting Kv currents. Elevated serotonin levels during pregnancy counterbalance pregnancy-related QT prolongation by facilitating Htr3-mediated Kv currents.

Ondansetron Inhibits Voltage-Gated K⁺ Current of Ventricular Myocytes from Pregnant Mouse

BACKGROUND: The Htr3a antagonist, ondansetron, has been reported to prolong the QT interval and induce Torsades de pointes in the treatment of postoperative nausea and vomiting. To explore the mechanisms underlying these findings, we examined the effects of ondansetron on the mouse cardiac voltage-gated K⁺ (Kv) channel. METHODS AND RESULTS: Ondansetron increased QT intervals in late pregnant (LP) mice. We measured the Kv channels in freshly isolated left ventricular (LV) myocytes from non-pregnant (NP) and late pregnant (LP) mice, using patch-clamp electrophysiology. Ondansetron blocked Kv current at a dose of 50 µM, and reduced the amplitude of peak current densities in a dose-dependent manner (0, 1, 5, 50 µM), in LP but not in NP mice. In contrast, serotonin and the Htr3 agonist, m-CPBG, increased Kv current densities in NP, but not in LP mice. Interestingly, during pregnancy, serum serotonin levels were markedly increased, suggesting the saturation of the effect of serotonin. Immunostaning data showed that Kv4.3 protein and Htr3a co-localize at the membrane and t-tubule of cardiomyocytes. Moreover, Kv4.3 membrane trafficking was enhanced in response to Htr3a-mediated serotonin stimulation in NP, but not in LP mice. Membrane analysis showed that serotonin enhances Kv4.3 membrane trafficking in NP, but not LP mice. CONCLUSION: Ondansetron reduced Kv current densities, and reduced the Kv4.3 membrane trafficking in LP mouse ventricular cardiomyocytes. This data suggests that QT prolongation by ondansetron is mediated by the reduction of Kv current densities and Kv4.3 membrane trafficking.

High Maternal Blood Mercury Level Is Associated with Low Verbal IQ in Children

The objective of the present study was to investigate the relationship of IQ in children with maternal blood mercury concentration during late pregnancy. The present study is a component of the Mothers and Children's Environmental Health (MOCEH) study, a multi-center birth cohort project in Korea that began in 2006. The study cohort consisted of 553 children whose mothers underwent testing for blood mercury during late pregnancy. The children were given the Korean language version of the Wechsler Preschool and Primary Scale of Intelligence, revised edition (WPPSI-R) at 60 months of age. Multivariate linear regression analysis, with adjustment for covariates, was used to assess the relationship between verbal, performance, and total IQ in children and blood mercury concentration of mothers during late pregnancy. The results of multivariate linear regression analysis indicated that a doubling of blood mercury was associated with the decrease in verbal and total IQ by 2.482 (95% confidence interval [CI], 0.749–4.214) and 2.402 (95% CI, 0.526–4.279), respectively, after adjustment. This inverse association remained after further adjustment for blood lead concentration. Fish intake is an effect modifier of child IQ. In conclusion, high maternal blood mercury level is associated with low verbal IQ in children.

Association of Foxp3 Polymorphism With Allograft Outcome in Kidney Transplantation

BACKGROUND: Forkhead box P3 (Foxp3) is the most reliable marker for regulatory T cells, which play an important role in maintaining renal allograft tolerance. Recently, Foxp3 polymorphisms have been reported to be associated with graft outcome in kidney transplantation. We analyzed the association of Foxp3 polymorphisms with renal allograft outcome. METHODS: Foxp3 polymorphisms (rs3761548 A/C, rs2280883 C/T, rs5902434 del/ATT, and rs2232365 A/G) were tested by PCR with sequence-specific primers (PCR-SSP) in 231 adult kidney transplantation recipients from 1996-2004 at Seoul National University Hospital. RESULTS: Patients with the rs3761548 CC genotype showed better graft survival than those with the AC or AA genotype (log rank test, P=0.03). Patients with the rs3761548 CC genotype also showed a lower rate of recurrence of the original glomerular disease than those with the AC or AA genotype (P=0.01). The frequency of acute rejection (AR) in patients with the rs2280883 TT genotype was lower than that in patients with the rs2280883 CT or CC genotype (26.9% vs 53.3%, P=0.038). Patients with the rs2280883 TT genotype also showed better graft survival than those with the CT or CC genotype (P=0.03). CONCLUSIONS: Foxp3 rs3761548 CC and rs2280883 TT genotypes were associated with superior graft outcome of kidney transplantation. Further studies involving a larger number of patients are needed.

The Effect of Low Birth Weight and Age on the Cognitive Performance of Preterm Preschoolers

OBJECTIVES: The current study examined the effect of birth weight on the relationship between age and IQ of children, who were born preterm with very low birth weight (VLBW) or extremely low birth weight (ELBW). METHODS: The study subjects were 82 children, aged between 3–5 years, who visited the neonatal intensive care unit of a university hospital located in Seoul. The children had been born prematurely with VLBW or ELBW. Their IQ was tested using the performed Korean-Wechsler Preschool and Primary Scale of Intelligence fourth edition. RESULTS: A hierarchical regression analysis showed a significant interaction effect of birth weight and age on Full Scale IQ (FSIQ); the effect of age on FSIQ differed according to birth weight. For the group with VLBW, FSIQ was more likely to be higher with increasing age. Conversely, for the group with ELBW, FSIQ remained low regardless of the age level. In addition, birth weight and age had a significant interaction effect on the Visual Spatial Index. Birth weight had a significant main effect on Verbal Comprehension Index. CONCLUSION: This research suggested the possibility of predicting the cognitive developmental of premature children, by highlighting the fact that prematurely born children, with VLBW/ELBW, have different cognitive developmental trajectories.

False-Positive T-Cell Cytotoxicity Crossmatch Results Due to Autoantibodies in Korean Network for Organ Sharing Crossmatch Tests / 대한이식학회지

BACKGROUND: Basic National Institute of Health (NIH) and sensitive antihuman globulin (AHG) methods are widely used for T-cell complement-dependent cytotoxicity crossmatch (XM) tests. Whereas NIH-negative, AHG-positive (NIH⁻/AHG⁺) results are caused by weak antibodies, NIH⁺/AHG⁻ results are usually due to autoantibodies. We found that solid organ transplantation candidates with NIH⁺/AHG⁻ XM results are repeatedly excluded from allocation of deceased donor organs by the Korean Network for Organ Sharing (KONOS) allocation system. Here, we attempted to demonstrate that these patients do not have donor-specific HLA antibodies (DSAs). METHODS: Sera showing NIH⁺/AHG⁻ results in the analysis of 1,668 KONOS T-cell XM tests were screened for panel reactive antibody (PRA) using a Luminex test. For screen-positive samples, antibody identification was conducted using a Luminex single antigen assay and the presence or absence of class I DSAs was determined. For positive controls, 42 KONOS XM tests showing probable true-positive (NIH⁻/AHG⁺ or NIH⁺/AHG⁺) results were reviewed for PRA results based on electronic medical records and the presence or absence of DSAs was determined. RESULTS: NIH⁺/AHG⁻ results were observed in 1.3% (21/1,668) of KONOS XM tests analyzed. Most of these (18/21, 85.7%) were negative for PRA or DSAs. All probable true-positive cases were either positive for DSAs (24/42, 57.1%) or had high PRA (mean, 92% [range; 42%~100%]), complicating accurate identification of antibody specificities. CONCLUSIONS: NIH⁺/AHG⁻ results are not rare (1.3%) in KONOS XM tests. Most of these results are not due to DSAs, and these patients should not be excluded from organ allocation.

Effect of Breastfeeding Duration on Cognitive Development in Infants: 3-Year Follow-up Study

We investigated the association between breastfeeding and cognitive development in infants during their first 3 years. The present study was a part of the Mothers' and Children's Environmental Health (MOCEH) study, which was a multi-center birth cohort project in Korea that began in 2006. A total of 697 infants were tested at age 12, 24, and 36 months using the Korean version of the Bayley Scales of Infant Development II (K-BSID-II). The use and duration of breastfeeding and formula feeding were measured. The relationship between breastfeeding and the mental development index (MDI) score was analyzed by multiple linear regression analysis. The results indicated a positive correlation between breastfeeding duration and MDI score. After adjusting for covariates, infants who were breastfed for ≥ 9 months had significantly better cognitive development than those who had not been breastfed. These results suggest that the longer duration of breastfeeding improves cognitive development in infants.

Interlaboratory Comparison of the Results of Lifecodes LSA Class I and Class II Single Antigen Kits for Human Leukocyte Antigen Antibody Detection

BACKGROUND: Although single antigen bead assays (SAB) are approved qualitative tests, the median fluorescence intensity (MFI) values obtained from SAB are frequently used in combination with quantitative significances for diagnostic purposes. To gauge the reproducibility of SAB results, we assessed the interlaboratory variability of MFI values using identical kits with reagents from the same lot and the manufacturer's protocol. METHODS: Six serum samples containing HLA-specific antibodies were analyzed at five laboratories by using Lifecodes LSA Class I and Class II SAB kits (Immucor, USA) from the same lot, according to the manufacturer's protocol. We analyzed the concordance of qualitative results according to distinct MFI cutoffs (1,000, 3,000, 5,000, and 10,000), and the correlation of quantitative MFI values obtained by the participating laboratories. The CV for MFI values were analyzed and grouped by mean MFI values from the five laboratories ( or =10,000). RESULTS: The categorical results obtained from the five laboratories exhibited concordance rates of 96.0% and 97.2% for detection of HLA class I and class II antibodies, respectively. The Pearson correlation coefficients for MFI values of class I and class II antibodies were between 0.947-0.991 and 0.992-0.997, respectively. The median CVs for the MFI values among five laboratories in the lower MFI range (<1,000) were significantly higher than those for the other MFI ranges (all P<0.01). CONCLUSIONS: Analysis of SAB performed in five laboratories using identical protocols and reagents from the same lot resulted in high levels of concordance and strong correlation of results.

The Impact of HLA and KIR Ligand Mismatching on Unrelated Allogeneic Hematopoietic Stem Cell Transplantation in Korean Adult Patients

BACKGROUND: The impact of HLA and KIR ligand mismatching on the outcome of hematopoietic stem cell transplantation (HSCT) remains unclear. Previous reports have identified considerable ethnic differences in the impact of HLA and KIR ligand mismatches, as well as KIR ligand status, on HSCT; however, to date, no data has been acquired in Korean adult patients. METHODS: We investigated the association of high-resolution HLA matching on five loci (HLA-A, -B, -C, -DRB1, and -DQB1), KIR ligand mismatching, and KIR ligand status on the outcome of allogeneic HSCT from unrelated donors in 154 Korean adult patients treated at Seoul National University Hospital. RESULTS: In a multivariate analysis, less than 9/10 allelic matches in five HLA loci was an independent risk factor for acute graft-versus-host disease (GVHD) (grade II to IV) (P=0.019, odds ratio [OR]=2.7). In addition, HLA-A allele mismatching was increasingly prevalent in patients with acute GVHD compared to patients without (61.9% vs. 34.5%, P=0.06). For KIR ligand status, the patient and donor combination of both C1/C1 ligands showed better event-free and overall survival than combinations with C2 ligand patients or donors (P=0.048, P=0.034, respectively) by log-rank test. CONCLUSIONS: Korean adult transplant patients with less than 9 of 10 HLA allele matches in the HLA-A, -B, -C, -DRB1, and DQB1 loci have a higher likelihood of developing acute GVHD (grade II to IV). Impact of KIR ligand status on clinical outcome should be further studied in a larger patient population.