Background: National reference standards for anti-HIV-1 antibody are needed to evaluate the performance and maintain the quality control of anti-HIV-1 antibody assays. The aim of this study was to prepare a mixed-titer performance panel and assess its suitability as a national reference standard for anti-HIV-1 antibody according to stability, collaboration, and other studies. Methods: Nineteen serum samples from different HIV patients were obtained, along with 15 units of fresh frozen plasma samples with negative anti-HIV-1 antibody results. Ten anti-HIV-1 antibody-positive candidate standards and two negative candidate standards were prepared based on the reactivity in the Alinity i HIV Ag/Ab combo assay (Abbott Laboratories, Wiesbaden, Germany). A collaborative study was conducted across eight laboratories using five anti-HIV-1 antibody assays. Real-time and accelerated stability were evaluated to assess the long-term stability. Results: In the collaborative study, results of all five anti-HIV-1 antibody assays were positive for all 10 candidate standards prepared using HIV patient samples. The CV of each assay for every candidate standard was within 10%, except for one assay result. No real-time and accelerated stability change trend was observed at −70°C or −20°C, supporting that the reference standards were maintained in a stable state at −70°C for long-term storage. Conclusions The overall results suggest that the 12 candidate standards could serve as national reference standards for anti-HIV-1 antibody.

Background: There has been no comparison of the determinants of admission route between acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We examined whether factors associated with direct versus transferred-in admission to regional cardiocerebrovascular centers (RCVCs) differed between AIS and AMI. Methods: Using a nationwide RCVC registry, we identified consecutive patients presenting with AMI and AIS between July 2016 and December 2018. We explored factors associated with direct admission to RCVCs in patients with AIS and AMI and examined whether those associations differed between AIS and AMI, including interaction terms between each factor and disease type in multivariable models. To explore the influence of emergency medical service (EMS) paramedics on hospital selection, stratified analyses according to use of EMS were also performed. Results: Among the 17,897 and 8,927 AIS and AMI patients, 66.6% and 48.2% were directly admitted to RCVCs, respectively. Multivariable analysis showed that previous coronary heart disease, prehospital awareness, higher education level, and EMS use increased the odds of direct admission to RCVCs, but the odds ratio (OR) was different between AIS and AMI (for the first 3 factors, AMI > AIS; for EMS use, AMI < AIS). EMS use was the single most important factor for both AIS and AMI (OR, 4.72 vs. 3.90). Hypertension and hyperlipidemia increased, while living alone decreased the odds of direct admission only in AMI;additionally, age (65–74 years), previous stroke, and presentation during non-working hours increased the odds only in AIS. EMS use weakened the associations between direct admission and most factors in both AIS and AMI. Conclusions Various patient factors were differentially associated with direct admission to RCVCs between AIS and AMI. Public education for symptom awareness and use of EMS is essential in optimizing the transportation and hospitalization of patients with AMI and AIS.

Objective: Isotretinoin should not be used during pregnancy because of the risk of birth defects. Most pregnant women exposed to isotretinoin choose voluntary pregnancy termination due to concerns about birth defects. However, birth outcome data supporting the termination of pregnancy are lacking. This study aimed to evaluate pregnancy and neonatal outcomes after periconception exposure to isotretinoin. Methods: This was a prospective cohort study. We evaluated pregnancy and neonatal outcomes after exposure to isotretinoin in 151 pregnant women. Among 1,026 callers at the Korean Teratology Information Service from 2001 to 2017 exposed to isotretinoin during the periconception period, 151 pregnant women who received counseling on teratogenic risk after visiting the clinic were included. Results: Among the 151 participants who visited the clinic, only 42 were evaluated using ultrasonography until approximately 20 weeks of gestation. Ultimately, 23 patients were included in the study. The average gestation period during the last exposure to the drug was 2 weeks, and the average daily exposure dose was 12 mg. There were two cases of major birth defects in the exposure group. Spontaneous abortion rates were 17.7% and 8.7% in the exposure and nonexposure groups, respectively (P=0.035). There was no significant difference between the exposure and non-exposure groups in terms of pregnancy and neonatal outcomes. Conclusion There was no significant difference in pregnancy and neonatal outcomes, including birth defects, between the exposure and non-exposure groups. Further studies with larger sample sizes are required to validate our findings.

Background/Aims: The long-term course of Crohn’s disease (CD) has never been evaluated in non-Caucasian population-based cohorts. The aim of the present study was to evaluate the longterm prognosis of Korean CD patients in the well-defined population-based Songpa-Kangdong inflammatory bowel disease cohort. Methods: Outcomes of disease and their predictors were evaluated for 418 patients diagnosed with CD between 1986 and 2015. Results: During a median of 123 months, systemic corticosteroids, thiopurines, and anti-tumor necrosis factor (TNF) agents were administered to 58.6%, 81.3%, and 37.1% of patients, respectively. Over time, the cumulative probability of starting corticosteroids significantly decreased (p=0.001), whereas that of starting thiopurines and anti-TNFs significantly increased (both p<0.001). The cumulative probability of behavioral progression was 54.5% at 20 years, and it significantly decreased during the anti-TNF era. Intestinal resection was required for 113 patients (27.0%). The cumulative probabilities of intestinal resection at 1, 5, 10, 20, and 25 years after CD diagnosis were 12.7%, 16.5%, 23.8%, 45.1%, and 51.2%, respectively. Multivariable Cox regression analysis identified stricturing behavior at diagnosis (adjusted hazard ratio [aHR], 2.70; 95% confidence interval [CI], 1.55 to 4.71), penetrating behavior at diagnosis (aHR, 11.15; 95% CI, 6.91 to 17.97), and diagnosis of CD during the anti-TNF era (aHR, 0.51; 95% CI, 0.35 to 0.76) as independently associated with intestinal resection. The standardized mortality ratio among CD patients was 1.36 (95% CI, 0.59 to 2.68). Conclusions The long-term prognosis of Korean patients with CD is at least as good as that of Western CD patients, as indicated by the low intestinal resection rate. Moreover, behavioral progression and intestinal resection rates have decreased over the past 3 decades.

Synovial hemangioma is a vascular malformation that usually involves the knee. This paper presents the diagnostic ultrasound findings of a synovial hemangioma that could be mistaken for a medial meniscus cyst in a 37-year-old man and report the clinical result of the meniscal repair after an open excision.

Background/Aims: This study was performed to undertake cross-cultural adaptation and validation of the Educational Needs Assessment Tool (ENAT) in rheumatoid arthritis (RA) for use in Korea. Methods: The study involved two main phases: cross-cultural adaptation of the ENAT from English into Korean, and validation of the Korean ENAT. The first phase followed the established process of cross-cultural adaptation of self-report measures, and in the second phase, the Korean ENAT data were analyzed using the Rasch measurement model. Fit to the model was determined using the observed data infit and outfit statistics. Additional tests of validity included unidimensionality and internal consistency. Results: Adequate conceptual equivalence was achieved following the adaptation process. A total of 123 patients completed the Korean ENAT. The mean age was 46.7 ± 12.3 years and the majority of patients (81.3%) were female. Thirty-five of the 39 items gave good fit to the model. The four items deviating from the model had infit and outfit > 1.50. The item separation index (5.26) and item reliability index (0.97) provided evidence for good reliability of items. All seven domains of the Korean ENAT fit the Rasch model. The internal consistency of the Korean ENAT was high, and unidimensionality was confirmed (person separation index, 3.41; reliability index, 0.92; item separation index, 16.82; reliability index, 1.00). Conclusions Using the standard procedure for cross-cultural adaptation, the ENAT has been adapted into Korean, and Rasch analysis has confirmed the construct validity, reliability, and unidimensionality of the Korean ENAT.

Background/Aims: This study was performed to undertake cross-cultural adaptation and validation of the Educational Needs Assessment Tool (ENAT) in rheumatoid arthritis (RA) for use in Korea. Methods: The study involved two main phases: cross-cultural adaptation of the ENAT from English into Korean, and validation of the Korean ENAT. The first phase followed the established process of cross-cultural adaptation of self-report measures, and in the second phase, the Korean ENAT data were analyzed using the Rasch measurement model. Fit to the model was determined using the observed data infit and outfit statistics. Additional tests of validity included unidimensionality and internal consistency. Results: Adequate conceptual equivalence was achieved following the adaptation process. A total of 123 patients completed the Korean ENAT. The mean age was 46.7 ± 12.3 years and the majority of patients (81.3%) were female. Thirty-five of the 39 items gave good fit to the model. The four items deviating from the model had infit and outfit > 1.50. The item separation index (5.26) and item reliability index (0.97) provided evidence for good reliability of items. All seven domains of the Korean ENAT fit the Rasch model. The internal consistency of the Korean ENAT was high, and unidimensionality was confirmed (person separation index, 3.41; reliability index, 0.92; item separation index, 16.82; reliability index, 1.00). Conclusions Using the standard procedure for cross-cultural adaptation, the ENAT has been adapted into Korean, and Rasch analysis has confirmed the construct validity, reliability, and unidimensionality of the Korean ENAT.