Immunogenicity and safety of concomitant bivalent COVID-19 and quadrivalent influenza vaccination: implications of immune imprinting and interference

OBJECTIVES

Concomitant COVID-19 and influenza vaccination would be an efficient strategy. Although the co-administration of monovalent COVID-19 and influenza vaccinations showed acceptable immunogenicity, it remains unknown whether the bivalent COVID-19 vaccine could intensify immune interference. We aimed to evaluate the immunogenicity and safety of concomitant BA.5-based bivalent COVID-19 and influenza vaccination.

METHODS

An open-label, nonrandomized clinical trial was conducted for 154 age-matched and sex-matched healthy adults between October 2022 and December 2022. Participants received either a concomitant bivalent COVID-19 mRNA booster and quadrivalent influenza vaccination (group C) or separate vaccinations (group S) at least 4 weeks apart. Solicited and unsolicited adverse events were reported up to 6 months postvaccination. Immunogenicity was evaluated by anti-spike (S) IgG electrochemiluminescence immunoassay, focus reduction neutralization test, and hemagglutination inhibition assay.

RESULTS

Group C did not meet the noninferiority criteria for the seroconversion rates of anti-S IgG and neutralizing antibodies against the wild-type SARS-CoV-2 strain compared with group S (44.2% vs. 46.8%, difference of -2.6% [95% CI, -18 to 13.4]; 44.2% vs. 57.1%, difference of -13.0% [95% CI to -28.9 to 2.9]). However, group C showed a stronger postvaccination neutralizing antibody response against Omicron BA.5 (72.7% vs. 64.9%). Postvaccination geometric mean titers for SARS-CoV-2 and influenza strains were similar between groups, except for influenza B/Victoria. Most adverse events were mild and comparable between the study groups.

DISCUSSION

Concomitant administration of bivalent COVID-19 mRNA and quadrivalent influenza vaccines showed tolerable safety profiles and sufficient immunogenicity, particularly attenuating immune imprinting induced by previous ancestral vaccine strains.

Incidence of Clostridioides difficile Infections in Republic of Korea: A Prospective Study With Active Surveillance vs. National Data From Health Insurance Review & Assessment Service

BACKGROUND

Since the emergence of hypervirulent strains of Clostridioides difficile, the incidence of C. difficile infections (CDI) has increased significantly.

METHODS

To assess the incidence of CDI in Korea, we conducted a prospective multicentre observational study from October 2020 to October 2021. Additionally, we calculated the incidence of CDI from mass data obtained from the Health Insurance Review and Assessment Service (HIRA) from 2008 to 2020.

RESULTS

In the prospective study with active surveillance, 30,212 patients had diarrhoea and 907 patients were diagnosed with CDI over 1,288,571 patient-days and 193,264 admissions in 18 participating hospitals during 3 months of study period; the CDI per 10,000 patient-days was 7.04 and the CDI per 1,000 admission was 4.69. The incidence of CDI was higher in general hospitals than in tertiary hospitals: 6.38 per 10,000 patient-days (range: 3.25-12.05) and 4.18 per 1,000 admissions (range: 1.92-8.59) in 11 tertiary hospitals, vs. 9.45 per 10,000 patient-days (range: 5.68-13.90) and 6.73 per 1,000 admissions (range: 3.18-15.85) in seven general hospitals. With regard to HIRA data, the incidence of CDI in all hospitals has been increasing over the 13-year-period: from 0.3 to 1.8 per 10,000 patient-days, 0.3 to 1.6 per 1,000 admissions, and 6.9 to 56.9 per 100,000 population, respectively.

CONCLUSION

The incidence of CDI in Korea has been gradually increasing, and its recent value is as high as that in the United State and Europe. CDI is underestimated, particularly in general hospitals in Korea.

Assessment of quality of care for hospitalized non-COVID-19 older adult patients with pneumonia before and after the COVID-19 pandemic

BACKGROUND

There is limited research into the clinical implications of the coronavirus disease 2019 (COVID-19) pandemic for non-COVID-19 pneumonia in older adults, as well as their quality of care or outcomes. This study aims to assess the process and outcome quality of care for hospitalized older adult patients with pneumonia before and after the pandemic.

METHODS

A retrospective cohort of older adult patients (age ≥ 65) hospitalized for non-COVID pneumonia were recruited from five Korean hospitals (January 20, 2019, to January 19, 2021). The quality of care before and after the COVID-19 pandemic was evaluated.

RESULTS

A total of 7356 hospitalization episodes of older adult pneumonia were identified, and 978 cases (552 pre-pandemic and 426 during the pandemic) were analyzed. The pneumonia severity score was higher during the pandemic, and the waiting time from the emergency room to admission was also longer. Furthermore, the pneumonia mortality rate during the pandemic was higher than that in the pre-pandemic period (in-hospital mortality: 10.1% vs. 18.1%; 90-day mortality: 11.6% vs. 22.3%). A significantly higher mortality risk was observed during the pandemic than in the period prior (adjusted odds ratio: 1.74, 95% confidence interval: 1.14-2.63).

CONCLUSIONS

While the quality of care for hospitalized pneumonia has been maintained during the pandemic, there has been an increase in mortality rates. Further investigations are needed to understand the underlying causes of this increase.

Changes in proteinuria and the associated risks of ischemic heart disease, acute myocardial infarction, and angina pectoris in Korean population

OBJECTIVES

Proteinuria is widely used to predict cardiovascular risk. However, there is insufficient evidence to predict how changes in proteinuria may affect the incidence of cardiovascular disease.

METHODS

The study included 265,236 Korean adults who underwent health checkups in 2003-2004 and 2007-2008. They were categorized into 4 groups based on changes in proteinuria (negative: negative → negative; resolved: proteinuria ≥1+ → negative; incident: negative → proteinuria ≥1+; persistent: proteinuria ≥1+ → proteinuria ≥1+). We conducted 6 years of follow-up to identify the risks of developing ischemic heart disease (IHD), acute myocardial infarction (AMI), and angina pectoris according to changes in proteinuria. A multivariate Cox proportional-hazards model was used to calculate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident IHD, AMI, and angina pectoris.

RESULTS

The IHD risk (expressed as HR [95% CI]) was the highest for persistent proteinuria, followed in descending order by incident and resolved proteinuria, compared with negative proteinuria (negative: reference, resolved: 1.211 [95% CI, 1.104 to 1.329], incident: 1.288 [95% CI, 1.184 to 1.400], and persistent: 1.578 [95% CI, 1.324 to 1.881]). The same pattern was associated with AMI (negative: reference, resolved: 1.401 [95% CI, 1.048 to 1.872], incident: 1.606 [95% CI, 1.268 to 2.035], and persistent: 2.069 [95% CI, 1.281 to 3.342]) and angina pectoris (negative: reference, resolved: 1.184 [95% CI, 1.065 to 1.316], incident: 1.275 [95% CI, 1.160 to 1.401], and persistent: 1.554 [95% CI, 1.272 to 1.899]).

CONCLUSIONS

Experiencing proteinuria increased the risks of IHD, AMI, and angina pectoris even after proteinuria resolved.

Association between CYP2D6 phenotype and recurrence of Plasmodium vivax infection in south Korean patients

Background

Primaquine is activated by CYP2D6 in the hepatocytes. In Korea, primaquine is the only hypnozoitocidal agent used for patients with vivax malaria. Thus, patients with poor CYP2D6 activity could have an increased risk of primaquine failure and subsequent relapse. The study sought to identify the association between CYP2D6 phenotype and recurrence of malaria in Korean patients.

Methods

A total of 102 patients with vivax malaria were prospectively enrolled from eight institutions in Korea. An additional 38 blood samples from patients with recurred vivax malaria were provided by the Korea Disease Control and Prevention Agency. Malaria recurrence was defined as more than one episode of vivax malaria in the same or consecutive years. CYP2D6 star alleles, phenotypes, and activity scores were examined.

Results

Genotyping for CYP2D6 was successful in 101 of the prospectively enrolled patients and 38 samples from the Korea Disease Control and Prevention Agency, of which 91 were included in the no-recurrence group and 48 were included in the recurrence group. Reduced CYP2D6 activity (intermediate metabolizer) phenotype was more common in the recurrence group than in the no-recurrence group (OR, 2.33 (95% CI, 1.14–4.77); p = 0.02). Patients with lower CYP2D6 activity had a higher probability of recurrence (p = 0.029).

Conclusion

This study suggests that CYP2D6 polymorphism may affect primaquine efficacy and thus Plasmodium vivax recurrence in Korea.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04311-6.

Effects of smoking cessation on the risk of cardiovascular disease: a nationwide population-based study

Introduction

Cardiovascular disease (CVD) is the global leading cause of death, and the economic and social burden of CVD is still increasing, Smoking is one of the top three leading risk factors for the disease and one of the well-established and important modifiable risk factors for CVD. However, the time course of CVD risk after smoking cessation is unclear.

Purpose

We assess the association between smoking and CVD and the incidence of CVD with years quitting smoking.

Methods

This study used the Korean National Health Insurance Service (NHIS) database. Self-reported smoking habit data were used to classify participants as current, former or never smokers and to investigate the duration and intensity of smoking. Smoking records of participants were updated every 2 years, and all participants whose smoking records were changed or unclear were excluded. The primary outcome was the development of CVD, including myocardial infarction, stroke, heart failure, and cardiovascular death.

Results

Total 5,391,231 participants (953,756 subjects were current smokers, 104,604 subjects were former smokers, 4,432,871 subjects never smoker) were followed-up for an average of 4.2 years. The mean age was 45.8 years, 39.9% were male. Cumulative pack-year (PY) were 14 in current smoker, 10.5 in former smokers at baseline. The median years of quitting smoking for former smoker was 4.

Regardless of whether smoking continues or not, a dose-dependent relationship exists between smoking and CVD (Fig. 1). For those smoked less than 8PY, smoking cessation significantly lowered the CVD risk within 10 years compared to current smokers, and the CVD risk was not significantly different from never smokers (Fig. 2A). However, in the case of smokers over 8PY, although smoking cessation affects the reduction of CVD, the CVD risk decreases slowly over decades, and it takes more than 20 years for the effect of smoking on the CVD risk to disappear (Fig. 2B).

Conclusion

Smoking and CVD have a dose-dependent relationship, and mild smokers with less than 8PY had a similar CVD risk to never smokers when quitting smoking. However, for heavy smokers over 8PY, it takes a long time for the CVD risk from smoking to disappear

Funding Acknowledgement

Type of funding sources: None.

Intracardiac echocardiographically guided permanent pacemaker implantation is a feasible imaging tool with comparable procedural efficacy and safety

Background

Amongst cardiovascular interventions, pacemaker implantation procedure is one of the most hazardous in terms of radiation exposure due to its proximity and unprotected radiation exposure. In order to reduce radiation hazards, alternative imaging tool to guide pacemaker implantation should be sought. The aim of this study is to investigate the feasibility, efficacy, and safety of intracardiac echocardiographically (ICE) guided pacemaker implantation.

Methods

We retrospectively investigated pacemaker implantation with ICE guidance. ICE catheter was placed in right atrium (RA). Right ventricular (RV) lead was placed in RV apex within home view (low RA, 2-4 O'clock). Then RA lead was placed in RA appendage within mid RA 1-2 O'clock view. Fluoroscopy was used only for verifying lead redundancy (2 or 3 second duration before pocket closure). Other procedure steps were similarly performed as in conventional fluoroscopic method. Radiation dosage, patient safety, total procedure time, and lead parameters were assessed and compared.

Results

From June 2013 to March 2021, a total of 270 patients underwent pacemaker implantation either with ICE or with fluoroscopy. Amongst them, ICE guided implantation was attempted in 35 patients. In order to exclude potential bias caused by the operator's learning curve, we excluded early 5 cases out of ICE group. Radiation exposure was markedly decreased within ICE group (2.3±4.4 Gy cm2 in ICE group vs. 27.2±50.5 Gy cm2 in fluoroscopy group, P<0.001). The total procedure time and complication rate showed no significant difference between groups. In ICE group, atrial lead parameters were better than those of fluoroscopy group (impedance 454±57 Ω vs. 533±125 Ω, P<0.001).

Conclusion

In 30 patients with ICE guided pacemaker implantation, radiation exposure was markedly decreased without any trade-offs in terms of patients' safety and procedural success. Furthermore, operation team members' physical stress reduction also might be potentially guaranteed.

Funding Acknowledgement

Type of funding sources: None.

Net clinical benefit of NOAC in Korean atrial fibrillation patients with low to intermediate stroke risk

Background

The balance of stroke risk reduction and potential hemorrhagic risk associated with anti-thrombotic treatment (ATT) remain unclear in Korean atrial fibrillation (AF) patients with low to intermediate stroke risk, defined as non-gender CHA2DS2-VASc score 0–1.

Purpose

The net clinical benefit (NCB) analysis of ATT may be helpful to guide stroke prevention strategy in AF patients with non-gender CHA2DS2-VASc score 0–1.

Methods

This Korean multi-center cohort study retrospectively evaluated the clinical outcomes with single antiplatelet (SAPT), vitamin K antagonist (VKA), and non-vitamin K antagonist oral anticoagulant (NOAC) in non-gender CHA2DS2-VASc score 0–1 and further stratified by biomarker-based ABCD score (Age [≥60 years], B-type natriuretic peptide [BNP] or N-terminal pro-BNP [≥300 pg/ml], Creatinine clearance [<50 ml/min/1.73 m2], and Dimension of the left atrium [≥45 mm]). The primary outcome was the NCB of ATT including thromboembolic and major bleeding events.

Results

We included 2465 patients (56.2±9.5 years; female, 665 [27.0%]) followed-up for 4.0±2.8 years, of whom 661 (26.8%) were treated with SAPT; 423 (17.2%) with VKA; and 1040 (42.2%) with NOAC. In comparison with no treatment, only NOAC demonstrated a positive tendency for stroke prevention (NOAC, NCB 0.47, 95% confidence interval [CI] −0.40 to 2.10; SAPT, NCB −0.31, 95% CI −1.48 to 1.40; and VKA, NCB −1.26, 95% CI −2.97 to 0.67). With detailed risk stratification with ABCD score, NOAC showed a significant NCB for stroke prevention compared with SAPT and VKA (SAPT vs. NOAC, NCB 1.6, 95% CI 0.26–3.50; VKA vs. NOAC, NCB 1.96, 95% CI 0.47–4.16) in patients with ABCD score ≥1. ATT failed to show NCB in patients with truly low stroke risk defined as ABCD score=0.

Conclusion

Korean AF cohort with low to intermediate stroke risk indicates that, in comparison with no ATT, only ATT with NOAC showed marginal NCB. With further risk stratification by ABCD score, NOAC showed significant advantages over other ATTs (VKA or SAPT) in patients with ABCD ≥1.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Disease Control and Prevention Agency

External validation of the biomarker based ABCD score in atrial fibrillation patients with a non gender CHA2DS2 VASc score 0 to 1, A Korean multicenter retrospective cohort

Background

Patients with low to intermediate risk atrial fibrillation (AF), defined as non-gender CHA2DS2-VASc score of 0–1, are still at risk of stroke. This study verified the usefulness of ABCD score (Age [≥60 years], B-type natriuretic peptide [BNP] or N-terminal pro-BNP [≥300 pg/ml], Creatinine clearance [<50 ml/min/1.73 m2], and Dimension of the left atrium [≥45 mm]) for stroke risk stratification in non-gender CHA2DS2-VASc score 0–1.

Methods

This multi-center cohort study retrospectively analyzed AF patients with non-gender CHA2DS2-VASc score 0–1. The primary endpoint was the incidence of stroke with or without anti-thrombotic treatment (ATT). An ABCD score was also validated.

Results

Overall, 2694 patients (56.3±9.5 years; female, 726 [26.9%]) were followed-up for 4.0±2.8 years. The overall stroke rate was 0.84/100 person-years (P-Y), stratified as follows: 0.46/100P-Y for an ABCD score 0; 1.02/100P-Y for an ABCD score≥1. The ABCD score was superior to the non-gender CHA2DS2-VASc score in stroke risk stratification (C-index=0.618, P=0.015; net reclassification improvement=0.576, P=0.040; integrated differential improvement=0.033, P=0.066). ATT was prescribed in 2353 patients (86.5%), and the stroke rate was significantly lower in patients receiving non-vitamin K antagonist oral anticoagulant (NOAC) therapy and an ABCD score≥1 than in those without ATT (0.44/100P-Y versus 1.55/100 P-Y; hazard ratio=0.26, 95% confidence interval 0.11–0.63, P=0.003).

Conclusion

The biomarker-based ABCD score demonstrated improved stroke risk stratification in AF patients with non-gender CHA2DS2-VASc score 0–1. Furthermore, NOAC with an ABCD score≥1 was associated with significantly lower stroke rate in AF patients with a non-gender CHA2DS2-VASc score 0–1.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Disease Control and Prevention Agency

Four Times of Relapse of Plasmodium vivax Malaria Despite Primaquine Treatment in a Patient with Impaired Cytochrome P450 2D6 Function

Plasmodium vivax exhibits dormant liver-stage parasites, called hypnozoites, which can cause relapse of malaria. The only drug currently used for eliminating hypnozoites is primaquine. The antimalarial properties of primaquine are dependent on the production of oxidized metabolites by the cytochrome P450 isoenzyme 2D6 (CYP2D6). Reduced primaquine metabolism may be related to P. vivax relapses. We describe a case of 4 episodes of recurrence of vivax malaria in a patient with decreased CYP2D6 function. The patient was 52-year-old male with body weight of 52 kg. He received total gastrectomy and splenectomy 7 months before the first episode and was under chemotherapy for the gastric cancer. The first episode occurred in March 2019 and each episode had intervals of 34, 41, and 97 days, respectively. At the first and second episodes, primaquine was administered as 15 mg for 14 days. The primaquine dose was increased with 30 mg for 14 days at the third and fourth episodes. Seven gene sequences of P. vivax were analyzed and revealed totally identical for all the 4 samples. The CYP2D6 genotype was analyzed and intermediate metabolizer phenotype with decreased function was identified.

Retrosternal hematoma in sternal fracture for prediction of concomitant injury on chest CT

BACKGROUND

Isolated sternal fracture, a benign injury, has been increasing in the pan-scan era, although one-third of patients with sternal fracture still has trouble with concomitant injury. The differentiation of these two entities is important to optimize patient management.

PURPOSE

To evaluate correlation between retrosternal hematoma and concomitant injury in patients with sternal fracture and to identify predicting factors for concomitant injury in sternal fracture.

MATERIAL AND METHODS

A total of 139 patients (84 men; mean age = 54.9 ± 15.3 years) with traumatic sternal fracture were enrolled in this study. We reviewed medical charts and multiplanar computed tomography (CT) images to evaluate cause, location, and degree of sternal fracture, retrosternal hematoma, and concomitant injury. Univariate and multivariate analysis were used to identify variables that were associated with concomitant injury.

RESULTS

Concomitant injury on chest CT was observed in 85 patients with sternal fracture. Of the patients, 98 (70.5%) were accompanied by retrosternal hematoma. Multivariate analysis revealed that retrosternal hematoma (odds ratio [OR] = 5.350; P < 0.001), manubrium fracture (OR = 6.848; P = 0.015), and motor vehicle accident (OR = 0.342; P = 0.015) were significantly associated with sternal fracture with concomitant injury.

CONCLUSION

Manubrium fracture and retrosternal hematoma portend a high risk of concomitant injury and indicate the need for further clinical and radiologic work-up.

Clinical application of next-generation sequencing for the management of desmoid tumors: A case report and literature review

RATIONALE

Desmoid tumors are rare myofibroblastic neoplasms characterized by local invasiveness and high rates of recurrence, and sometimes mimic local recurrence of previously resected malignancies. Previous studies have suggested that molecular profiling may be useful for the diagnosis of the tumors and risk stratification. However, the clinical utility of next-generation sequencing (NGS) for the management of desmoid tumors has not been established.

PATIENT CONCERNS

A 42-year-old man visited our clinic for routine follow-up 1 year after left upper lobe lingular segmentectomy for lung adenocarcinoma.

DIAGNOSES

Chest computed tomography showed a pleural mass adherent to the thoracotomy site. Positron emission tomography revealed mildly increased metabolism with a maximal standardized uptake value of 2.7 within the tumor, suggesting local recurrence of the previous neoplasm. Exploratory thoracotomy and en bloc resection of the tumor revealed spindle cells in a massive collagenous tissue consistent with a desmoid tumor.

INTERVENTIONS

NGS was performed to confirm the diagnosis and to identify any genetic alterations that might be relevant to the prognosis of this tumor. The tumor harbored an S45F mutation in CTNNB1, which has been correlated with a high recurrence rate. Therefore, we performed adjuvant radiotherapy on the resection bed at a dose of 56 Gy.

OUTCOMES

The patients experienced no postoperative or radiotherapy-related complications. Periodic follow-up examinations using computed tomography were performed every 3 months, and no evidence of recurrence of either tumor was observed during the 38 months after the last surgery.

LESSONS

To the best of our knowledge, this is the first case reporting the clinical application of NGS and aggressive treatment based on the genotyping results for the management of a desmoid tumor. Our case highlights the need to consider desmoid tumors among the differential diagnoses when a pleural mass is encountered at a previous thoracotomy site. More importantly, molecular profiling using NGS can be useful for the establishment of a treatment strategy for this tumor, although further investigations are required.

Comparison of antiviral effect for mild-to-moderate COVID-19 cases between lopinavir/ritonavir versus hydroxychloroquine: A nationwide propensity score-matched cohort study

OBJECTIVES

We aimed to compare the antiviral effect of hydroxychloroquine (HCQ) and lopinavir/ritonavir (LPV/r) in patients with COVID-19.

METHODS

Nationwide retrospective case-control study was conducted to compare the effect of HCQ and LPV/r on viral shedding duration among patients with mild-to-moderate COVID-19 using the reimbursement data of National Health Insurance Service. After propensity score matching (PSM), multivariate analysis was conducted to determine statistically significant risk factors associated with prolonged viral shedding.

RESULTS

Overall, 4197 patients with mild-to-moderate COVID-19 were included. Patients were categorized into three groups: LPV/r (n = 1268), HCQ (n = 801), and standard care without HCQ or LPV/r (controls, n = 2128). The median viral shedding duration was 23 (IQR 17-32), 23 (IQR 16-32), and 18 (IQR 12-25) days in the LPV/r, HCQ, and control groups, respectively. Even after PSM, the viral shedding duration was not significantly different between LPV/r and HCQ groups: 23 (IQR, 17-32) days versus 23 (IQR, 16-32) days. On multivariate analysis, old age, malignancy, steroid use, and concomitant pneumonia were statistically significant risk factors for prolonged viral shedding.

CONCLUSION

The viral shedding duration was similar between HCQ and LPV/r treatment groups. There was no benefit in improving viral clearance compared to the control group.

Case report of tracheobronchial injuries after acid ingestion: CT findings with serial follow-up: Airway complication after acid ingestion

RATIONALE

Tracheobronchial injury from acid ingestion is a less reported clinical presentation than injury of the gastrointestinal tract, but it can occur due to direct exposure from acid aspiration and cause fatal complications.

PATIENT CONCERNS

A 43-year-old man presented to the emergency department after ingesting nitric acid complaining of chest pain and dyspnea.

DIAGNOSES

The initial chest computed tomography (CT) images revealed an acute lung injury related to acid aspiration. The follow-up chest CT showed acute and late tracheobronchial injures.

INTERVENTIONS

Bronchoscopy showed deep caustic airway injuries consisting of hemorrhage, sloughing of the mucosa, and ulceration of the trachea and left-side bronchial tree.

OUTCOMES

Progressive narrowing of the left main bronchus with total collapse of the left lung occurred as a late complication of acid ingestion.

LESSONS

Tracheobronchial injury should be considered in cases of aspiration pneumonia after acid ingestion; chest CT can be used to detect and assess acute and late complications of tracheobronchial injuries.

Primary Resistance to Immune Checkpoint Blockade in an STK11/TP53/KRAS-Mutant Lung Adenocarcinoma with High PD-L1 Expression

Several studies have shown that STK11 and TP53 mutations have different effects on the susceptibility to immune checkpoint blockade in KRAS-mutant non-small cell lung cancer (NSCLC). However, the impact of STK11/TP53 co-mutations on treatment outcomes in the same clinical setting has never been reported. We recently encountered a case of a 70-year-old man who was diagnosed with advanced lung adenocarcinoma with high-programmed death-ligand 1 (PD-L1) expression. He received pembrolizumab monotherapy as a frontline treatment; however, the tumor did not respond to this therapy and showed deleterious outcome. Next-generation sequencing revealed that the tumor harbored a rare STK11/TP53/KRAS triple mutation. Our case suggests that these compound mutations may constitute a distinct, aggressive subset that is resistant to immunotherapy even when the tumor strongly expresses PD-L1. In addition, this report highlights the importance of using molecular profiling to detect co-mutations that can be associated with primary resistance or disease progression to improve survival even in the immunotherapy setting.

Clinical Utility of Quantitative CT Analysis for Fissure Completeness in Bronchoscopic Lung Volume Reduction: Comparison between CT and Chartis™

Objective

The absence of collateral ventilation (CV) is crucial for effective bronchoscopic lung volume reduction (BLVR) with an endobronchial valve. Here, we assessed whether CT can predict the Chartis™ results.

Materials and Methods

This study included 69 patients (mean age: 70.9 ± 6.6 years; 66 [95.7%] males) who had undergone CT to assess BLVR eligibility. The Chartis™ system (Pulmonox Inc.) was used to check CV. Experienced thoracic radiologists independently determined the completeness of fissures on volumetric CT images.

Results

The comparison between the visual and quantitative analyses revealed that 5% defect criterion showed good agreement. The Chartis™ assessment was performed for 129 lobes; 11 (19.6%) of 56 lobes with complete fissures on CT showed positive CV, while this rate was significantly higher (40 of 49 lobes, i.e., 81.6%) for lobes with incomplete fissures. The size of the fissure defect did not affect the rate of CV. Of the patients who underwent BLVR, 22 of 24 patients (91.7%) with complete fissures and three of four patients with incomplete fissures (75%) achieved target lobe volume reduction (TLVR).

Conclusion

The quantitative analysis of fissure shows that incomplete fissures increased the probability of CV on Chartis™, while the defect size did not affect the overall rates. TLVR could be achieved even in some patients with relatively large fissure defect, if they showed negative CV on Chartis™.

Measurement accuracy of lung nodule volumetry in a phantom study: Effect of axial-volume scan and iterative reconstruction algorithm

An axial-volume scan with adaptive statistical iterative reconstruction-V (ASIR-V) is newly developed. Our goal was to identify the influence of axial-volume scan and ASIR-V on accuracy of automated nodule volumetry.An "adult' chest phantom containing various nodules was scanned using both helical and axial-volume modes at different dose settings using 256-slice CT. All CT scans were reconstructed using 30% and 50% blending of ASIR-V and filtered back projection. Automated nodule volumetry was performed using commercial software. The image noise, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were measured.The axial-volume scan reduced radiation dose by 19.7% compared with helical scan at all radiation dose settings without affecting the accuracy of nodule volumetric measurement (P = .375). Image noise, CNR, and SNR were not significantly different between two scan modes (all, P > .05).The use of axial-volume scan with ASIR-V achieved effective radiation dose reduction while preserving the accuracy of nodule volumetry.

Combined CT texture analysis and nodal axial ratio for detection of nodal metastasis in esophageal cancer

OBJECTIVE

To assess the accuracy of a combination of CT texture analysis (CTTA) and nodal axial ratio to detect metastatic lymph nodes (LNs) in esophageal squamous cell carcinoma (ESCC).

METHODS

The contrast-enhanced chest CT images of 78 LNs (40 metastasis, 38 benign) from 38 patients with ESCC were retrospectively analyzed. Nodal axial ratios (short-axis/long-axis diameter) were calculated. CCTA parameters (kurtosis, entropy, skewness) were extracted using commercial software (TexRAD) with fine, medium, and coarse spatial filters. Combinations of significant texture features and nodal axial ratios were entered as predictors in logistic regression models to differentiate metastatic from benign LNs, and the performance of the logistic regression models was analyzed using the area under the receiver operating characteristic curve (AUROC).

RESULTS

The mean axial ratio of metastatic LNs was significantly higher than that of benign LNs (0.81 ± 0.2 vs 0.71 ± 0.1, p = 0.005; sensitivity 82.5%, specificity 47.4%); namely, significantly more round than benign. The mean values of the entropy (all filters) and kurtosis (fine and medium) of metastatic LNs were significantly higher than those of benign LNs (all, p < 0.05). Medium entropy showed the best performance in the AUROC analysis with 0.802 (p < 0.001; sensitivity 85.0%, specificity 63.2%). A binary logistic regression analysis combining the nodal axial ratio, fine entropy, and fine kurtosis identified metastatic LNs with 87.5% sensitivity and 65.8% specificity (AUROC = 0.855, p < 0.001).

CONCLUSION

The combination of CTTA features and the axial ratio of LNs has the potential to differentiate metastatic from benign LNs and improves the sensitivity for detection of LN metastases in ESCC.

ADVANCES IN KNOWLEDGE

The combination of CTTA and nodal axial ratio has improved CT sensitivity (up to 87.5%) for the diagnosis of metastatic LNs in esophageal cancer.

P997Improving left atrial appendage occluder size determination by using 3-dimensional printing model of the left atrial appendage

Introduction

Given the complexity of left atrial appendage (LAA) structure, current 2D based LAA occluder (LAAO) size prediction system using transesophageal echocardiography (TEE) has limitations.

Objective

To assess the accuracy of LAAO size determination method by implantation simulation using a 3D printed model compared with a conventional method based on TEE.

Methods

We retrospectively reviewed 57 cases with percutaneous LAAO using Amplatzer Cardiac Plug and Amulet from 2014 to 2018. We excluded cases without cardiac CT (21 cases) or with peri-device leakage or inappropriate position of the device on six months follow up TEE (6 cases), or with paroxysmal atrial fibrillation (2 cases). We finally included 28 cases with anatomically and physiologically properly implanted LAAO, using the final size of the implanted devices as a standard for the size prediction accuracy. We generated 3D printing model from cardiac CT images. LAAO size was determined with device implantation simulation using 3D printing model and occluder devices (Figure C), and conventional 2D TEE measurements by two experienced cardiologists who were blinded to the size of the finally implanted device.

Results

The accuracy in size of 3D printed left atrium (LA) models, compared with CT image sources, were validated by measuring the distance between artifacts which were intentionally implanted to LA model during image processing. There was minimal bias (−0.11 mm) between 3D images and printed LA models (Figure A). As plotted in Figure B, LAAO sizing by implantation simulation with 3D printing model showed excellent agreement with actually implanted LAAO size (r=0.927; bias=0.7±2.5), while LAAO sizing by 2D TEE measurements remained poor (r=0.544; bias 2.3±6.7).

Conclusions

LAAO size determination by using 3D printing model of LAA showed excellent accuracy. A prospective study to evaluate the clinical utility of this method should be done in future.

P1026Risk factors for the occurrence of stroke after atrial fibrillation ablation

Background

Risk factors for the occurrence of embolic stroke (ES) after atrial fibrillation (AF) ablation have not been fully elucidated. Our aim was to assess incidence of ES during long-term follow-up following AF ablation and to identify predicting factors associated with post-ablation ES.

Methods

We enrolled patients who experienced ES after AF ablation and body mass index-matched controls from AF ablation registries. Epicardial adipose tissue (EAT) was assessed using multislice computed tomography prior to ablation.

Results

A total of 3,464 patients who underwent AF ablation were recruited. During a mean follow-up of 47.2 months, ES occurred in 47 patients (1.36%) with a mean CHA2DS2-VAS score of 2.15 and overall incidence of ES was 0.34 per 100 patients/year. Compared with control group (n=190), ES group had more higher prior thromboembolic event and AF recurrence rates, larger LA size, lower creatinine clearance rate (CCr), and greater total and periatrial EAT volumes although no differences in AF type, CHA2DS2-VASc score, ablation extent, and anti-thrombotics use were found. On multivariate regression analysis, a prior history of thromboembolism, CCr, and periatrial EAT volume were independently associated with ES occurrence after AF ablation.

Cox regression analysis Risk factor Univariate Multivariate HR (95% CI) p value HR (95% CI) p value Age 1.017 (0.984–1.051) 0.31 Prior thromboembolism 2.488 (1.134–5.460) 0.023 2.916 (1.178–7.219) 0.021 CHA2DS2-VASc score 1.139 (0.899–1.445) 0.282 CCr 0.984 (0.970–0.999) 0.038 0.982 (0.996–0.998) 0.029 LA diameter (mm) 1.070 (1.012–1.130) 0.017 1.072 (0.999–1.150) 0.054 EAT_total (ml) 1.020 (1.010–1.029) <0.001 1.008 (0.993–1.023) 0.297 EAT_periatrial (ml) 1.085 (1.045–1.126) <0.001 1.065 (1.005–1.128) 0.032 PVI + additional ablation 0.846 (0.460–1.557) 0.592 No anticoagulant use 0.651 (0.346–1.226) 0.184 Recurrence 2.011 (1.007–4.013) 0.048 1.240 (0.551–2.793) 0.603 CCr, creatinine clearance rate; EAT, epicardial adipose tissue; LA, left atrium; PVI, pulmonary vein isolation.

K-M curve for stroke-free survival

Conclusions

Incidence of ES after AF ablation was lower than expected rate based on CHA2DS2-VASc score even though anticoagulants use was limited. Periatrial EAT volume, a prior thromboembolism event, and CCr were independent factors in predicting ES irrespective of AF recurrence and CHA2DS2-VASc score in patients who underwent AF ablation.

Quantitative computed tomography texture analysis: can it improve diagnostic accuracy to differentiate malignant lymph nodes?

Background and objective

Mediastinal lymph node (LN) staging in individuals with non-small-cell lung cancer plays an important role in staging and treatment planning. This study aimed to assess the accuracy of computed tomography (CT) texture analysis (CTTA) in differentiating benign and malignant mediastinal LNs.

Methods

Pathologically confirmed malignant and benign mediastinal LN samples, obtained using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), were retrospectively reviewed, in addition to chest CT and 18-fluorodeoxyglucose (FDG) uptake positron emission tomography (PET) data. For each LN, CTTA was performed using “AVIEW” software (Coreline Soft, Republic of Korea) by drawing a region of interest.

Results

A total of 132 LNs from 80 patients were included and classified into two groups according to pathology results: malignant (n = 61) and benign (n = 71). In EBUS, size > 1 cm, round shape, heterogeneous echogenicity, and presence of coagulation necrosis sign were more prevalent in malignant than in benign LNs; length was the only feature that distinguished the two groups. Among CTTA features, compactness and normalized standard deviation (SD) showed differences between the two groups. The ability to distinguish malignant LNs was higher using high standard uptake value (SUV) on FDG PET/CT (SUV_max ≥ 5) and normalized SD on CTTA (area under the receiver operating characteristic curve 0.739 versus 0.742, respectively); however, normalized SD demonstrated very low sensitivity despite high specificity.

Conclusions

CTTA may be helpful in distinguishing between benign and malignant LNs; however, the diagnostic value was not high. Therefore, integrated evaluation with other imaging modalities is needed.

Electronic supplementary material

The online version of this article (10.1186/s40644-019-0214-8) contains supplementary material, which is available to authorized users.

Application of next-generation sequencing to detect variants of drug-resistant Mycobacterium tuberculosis: genotype-phenotype correlation

BACKGROUND

Drug resistance in Mycobacterium tuberculosis (MTB) is a major health issue worldwide. Recently, next-generation sequencing (NGS) technology has begun to be used to detect resistance genes of MTB. We aimed to assess the clinical usefulness of Ion S5 NGS TB research panel for detecting MTB resistance in Korean tuberculosis patients.

METHODS

Mycobacterium tuberculosis with various drug resistance profiles including susceptible strains (N = 36) were isolated from clinical specimens. Nucleic acids were extracted from inactivated culture medium and underwent amplicon-based NGS to detect resistance variants in eight genes (gyrA, rpoB, pncA, katG, eis, rpsL, embB, and inhA). Data from previous studies using the same panel were merged to yield pooled sensitivity and specificity values for detecting drug resistance compared to phenotype-based methods.

RESULTS

The sequencing reactions were successful for all samples. A total of 24 variants were considered to be related to resistance, and 6 of them were novel. Agreement between the phenotypic and genotypic results was excellent for isoniazid, rifampicin, and ethambutol, and was poor for streptomycin, amikacin, and kanamycin. The negative predictive values were greater than 97% for all drug classes, while the positive predictive values varied (44% to 100%). There was a possibility that common mutations could not be detected owing to the low coverage.

CONCLUSIONS

We successfully applied NGS for genetic analysis of drug resistances in MTB, as well as for susceptible strains. We obtained lists of polymorphisms and possible polymorphisms, which could be used as a guide for future tests applying NGS in mycobacteriology laboratories. When analyzing the results of NGS, coverage analysis of each samples for each gene and benign polymorphisms not related to drug resistance should be considered.

Evaluation of a new matrix-assisted laser desorption/ionization time-of-flight mass spectrometry system for the identification of yeast isolation

BACKGROUND

Currently, three commercial in vitro diagnostic matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems are widely used in clinical laboratories. The ASTA MicroIDSys system (ASTA Inc, South Korea) is a newly developed MALDI-TOF MS system used for the identification of pathogenic microorganisms. In the present study, we assessed the performance of the ASTA MALDI-TOF MS system for the identification of pathogenic yeast from clinical samples.

METHODS

We tested 284 clinical yeast isolates from various clinical specimens using ASTA MALDI-TOF MS, and the results were compared with those using molecular sequencing of the ITS or D1-D2 regions of rDNA and biochemical assays.

RESULTS

A total of 284 isolates were tested and found to be distributed across 14 species including Candida albicans (n = 100) and other yeast species (n = 184). ASTA MALDI-TOF MS correctly identified 95.1% (270/284) of the yeast species compared to molecular sequencing. Among them, 262 isolates showed acceptable MALDI-TOF MS scores (≥140), and 98.1% (257/262) isolates were identified correctly. In addition, among 22 isolates with a MALDI-TOF MS score <140, 59.1% (13/22) of the isolates showed concordance with molecular typing at the species level. Clustering analysis revealed the effectiveness of the new MALDI-TOF MS system for the identification of yeast species.

CONCLUSIONS

ASTA MALDI-TOF MS showed high accuracy in the identification of yeast species; it involves facile sample preparation and extraction procedures. ASTA MALDI-TOF MS is expected to be useful for yeast identification in clinical microbiology laboratories due to its reliability and cost-effectiveness.

Determining Genotypic Drug Resistance by Ion Semiconductor Sequencing With the Ion AmpliSeq™ TB Panel in Multidrug-Resistant Mycobacterium tuberculosis Isolates

BACKGROUND

We examined the feasibility of a full-length gene analysis for the drug resistance-related genes inhA, katG, rpoB, pncA, rpsL, embB, eis, and gyrA using ion semiconductor next-generation sequencing (NGS) and compared the results with those obtained from conventional phenotypic drug susceptibility testing (DST) in multidrug-resistant Mycobacterium tuberculosis (MDR-TB) isolates.

METHODS

We extracted genomic DNA from 30 pure MDR-TB isolates with antibiotic susceptibility profiles confirmed by phenotypic DST for isoniazid (INH), rifampin (RIF), ethambutol (EMB), pyrazinamide (PZA), amikacin (AMK), kanamycin (KM), streptomycin (SM), and fluoroquinolones (FQs) including ofloxacin, moxifloxacin, and levofloxacin. Enriched ion spheres were loaded onto Ion PI Chip v3, with 30 samples on a chip per sequencing run, and Ion Torrent sequencing was conducted using the Ion AmpliSeq TB panel (Life Technologies, USA).

RESULTS

The genotypic DST results revealed good agreement with the phenotypic DST results for EMB (Kappa 0.8), PZA (0.734), SM (0.769), and FQ (0.783). Agreements for INH, RIF, and AMK+KM were not estimated because all isolates were phenotypically resistant to INH and RIF, and all isolates were phenotypically and genotypically susceptible to AMK+KM. Moreover, 17 novel variants were identified: six (p.Gly169Ser, p.Ala256Thr, p.Ser383Pro, p.Gln439Arg, p.Tyr597Cys, p.Thr625Ala) in katG, one (p.Tyr113Phe) in inhA, five (p.Val170Phe, p.Thr400Ala, p.Met434Val, p.Glu812Gly, p.Phe971Leu) in rpoB, two (p.Tyr319Asp and p.His1002Arg) in embB, and three (p.Cys14Gly, p.Asp63Ala, p.Gly162Ser) in pncA.

CONCLUSIONS

Ion semiconductor NGS could detect reported and novel amino acid changes in full coding regions of eight drug resistance-related genes. However, genotypic DST should be complemented and validated by phenotypic DSTs.

Drug susceptibility patterns of Mycobacterium abscessus and Mycobacterium massiliense isolated from respiratory specimens

In this study, we aimed to retrospectively investigate and compare the drug susceptibility patterns of two major Mycobacterium abscessus complex (MABC) species; M. abscessus and M. massiliense. A total of 546 MABC respiratory isolates (277 M. abscessus and 269 M. massiliense) from 2011 to 2016 were analyzed in this study. We estimated minimum inhibitory concentrations (MICs) using the broth microdilution method, and we calculated MIC₅₀ and MIC₉₀ values from the MIC distribution. Both M. abscessus and M. massiliense were highly susceptible to amikacin and linezolid. For M. abscessus, the proportions of inducible and acquired resistance to clarithromycin were 68.6% and 12.3%, respectively. Only 15.2% of M. abscessus remained susceptible at day 14. On the other hand, none of the M. massiliense showed inducible resistance and 6.3% showed acquired resistance to clarithromycin. A total of 92.6% of the M. massiliense remained susceptible at day 14. The resistance rate of M. abscessus to moxifloxacin (90.3%) was significantly higher than that of M. massiliense (83.3%; p = 0.016). These susceptibility differences may explain the divergent treatment outcomes between patients with pulmonary disease caused by these two species.

Comparative Evaluation of the Loop-Mediated Isothermal Amplification Assay for Detecting Pulmonary Tuberculosis

Background

Early detection of tuberculosis (TB) is challenging in resource-poor settings because of limited accessibility to molecular diagnostics. The aim of this study was to evaluate the performance of the loop-mediated isothermal amplification kit (TB-LAMP) for TB diagnosis compared with conventional and molecular tests.

Methods

A total of 290 consecutive sputum samples were collected from May till September, 2015. All samples were processed using the N-Acetyl-L-cysteine (NALC) NaOH method and tested by smear microscopy, solid and liquid culture, real-time PCR, and TB-LAMP.

Results

The sensitivity of TB-LAMP for smear-positive and smear-negative samples with culture positivity was 92.0% and 58.8%, respectively. TB-LAMP was positive in 14.9% of TB culture-negative samples; however, all those samples were also positive by real-time PCR. In addition, none of the samples positive for nontuberculous mycobacteria by culture were positive by TB-LAMP. The overall agreement between TB-LAMP and real-time PCR was good; however, the concordance rate was significantly lower for real-time PCR positive samples with Ct values of 30–35.

Conclusions

TB-LAMP could replace smear microscopy and increase TB diagnostic capacity when Xpert MTB/RIF is not feasible because of poor infrastructure.

Image quality assessment with dose reduction using high kVp and additional filtration for abdominal digital radiography

PURPOSE

Dose reduction using additional filters with high kilovoltage peak (kVp) for abdominal digital radiography has received much attention recently. We evaluated image quality with dose reduction in abdominal digital radiography by using high kVp and additional copper filters at a tertiary hospital.

METHODS

Between June 2016 and July 2016, 82 patients underwent abdominal digital radiography using 80 kVp in X-ray room 1 and 82 were imaged using 92 kVp with 0.1-mm copper filtration in X-ray room 2. The effective dose was calculated using a PC-based Monte Carlo program. Image quality of the abdominal radiography acquired in the two rooms was evaluated using a five-point ordinal scale, as well as the signal-to-noise and contrast-to-noise ratios.

RESULTS

The mean effective dose decreased by 25.8% and 25.7% for the supine and standing positions, respectively, when abdominal digital radiography using 92 kVp with 0.1-mm copper filtration was performed. In the 20 patients who performed abdominal digital radiography twice in each room, visual grading scores for visualisation of psoas outlines and kidney outlines are higher in room 1. However, there was no statistical significant difference of visual grading scores among the 124 patients who underwent only one abdominal radiography in the room 1 or 2 (P > 0.05).

CONCLUSIONS

Dose reduction for abdominal digital radiography can be achieved with comparable image quality by performing abdominal digital radiography using 92 kVp with 0.1-mm copper filtration, despite the higher AEC dose.

Incidental adult polysplenia with situs inversus, interrupted inferior vena cava with azygos continuation, patent ductus arteriosus, and aortic branches variations: a case report

Polysplenia syndrome is a rare condition (about 2.5:100,000 live births) wherein a person has two or more spleens with accompanying various thoracic and abdominal organ abnormalities. Polysplenia is usually associated with situs ambiguous, while polysplenia with situs inversus is very rare. Herein, we report a rare case of incidentally found polysplenia syndrome combined with situs inversus in a 59-year-old female who also had an interrupted inferior vena cava (IVC) with azygos continuation, patent ductus arteriosus (PDA), and variations in the aortic arch branches. An aberrant left subclavian artery with Kommerell's diverticulum and a large aneurysm in the non-aberrant, proximal-right subclavian artery were also noted.

Drug Resistance Patterns of Multidrug- and Extensively Drug-Resistant Tuberculosis in Korea: Amplification of Resistance to Oral Second-line Drugs

We aimed to analyze the drug resistance patterns of multidrug-resistant and extensively drug-resistant tuberculosis (TB) and the difference of drug resistance among various settings for health care in Korea. The data of drug susceptibility testing in 2009 was analyzed in order to secure sufficient number of patients from various settings in Korea. Patients were categorized by types of institutions into four groups, which comprised new and previously treated patients from public health care centers (PHC), the private sector, and Double-barred Cross clinics (DBC). The resistance rates to first-line drugs were uniformly high in every group. While the resistance rates to second-line drugs were not as high as first-line drugs, there was a pattern that drug resistance rates were lowest for PHC and highest for DBC. The differences of the resistance rates were more prominent for oral second-line drugs. Our findings implied that drug resistance to oral second-line drugs was significantly amplified during multidrug-resistant-TB treatment in Korea. Therefore, an individualized approach is recommended for treating drug-resistant-TB based on susceptibility testing results to prevent acquisition or amplification of drug resistance.

Innate-like Cytotoxic Function of Bystander-Activated CD8+ T Cells Is Associated with Liver Injury in Acute Hepatitis A

Acute hepatitis A (AHA) involves severe CD8⁺ T cell-mediated liver injury. Here we showed during AHA, CD8⁺ T cells specific to unrelated viruses became activated. Hepatitis A virus (HAV)-infected cells produced IL-15 that induced T cell receptor (TCR)-independent activation of memory CD8⁺ T cells. TCR-independent activation of non-HAV-specific CD8⁺ T cells were detected in patients, as indicated by NKG2D upregulation, a marker of TCR-independent T cell activation by IL-15. CD8⁺ T cells derived from AHA patients exerted innate-like cytotoxicity triggered by activating receptors NKG2D and NKp30 without TCR engagement. We demonstrated that the severity of liver injury in AHA patients correlated with the activation of HAV-unrelated virus-specific CD8⁺ T cells and the innate-like cytolytic activity of CD8⁺ T cells, but not the activation of HAV-specific T cells. Thus, host injury in AHA is associated with innate-like cytotoxicity of bystander-activated CD8⁺ T cells, a result with implications for acute viral diseases.

Comparison and Combination of Strain and Shear Wave Elastography of Breast Masses for Differentiation of Benign and Malignant Lesions by Quantitative Assessment: Preliminary Study

OBJECTIVES

To compare the diagnostic performance of strain and shear wave elastography of breast masses for quantitative assessment in differentiating benign and malignant lesions and to evaluate the diagnostic accuracy of combined strain and shear wave elastography.

METHODS

Between January and February 2016, 37 women with 45 breast masses underwent both strain and shear wave ultrasound (US) elastographic examinations. The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) final assessment on B-mode US imaging was assessed. We calculated strain ratios for strain elastography and the mean elasticity value and elasticity ratio of the lesion to fat for shear wave elastography. Diagnostic performances were compared by using the area under the receiver operating characteristic curve (AUC).

RESULTS

The 37 women had a mean age of 47.4 years (range, 20-79 years). Of the 45 lesions, 20 were malignant, and 25 were benign. The AUCs for elasticity values on strain and shear wave elastography showed no significant differences (strain ratio, 0.929; mean elasticity, 0.898; and elasticity ratio, 0.868; P > .05). After selectively downgrading BI-RADS category 4a lesions based on strain and shear wave elastographic cutoffs, the AUCs for the combined sets of B-mode US and elastography were improved (B-mode + strain, 0.940; B-mode + shear wave; 0.964; and B-mode, 0.724; P < .001). Combined strain and shear wave elastography showed significantly higher diagnostic accuracy than each individual elastographic modality (P = .031).

CONCLUSIONS

These preliminary results showed that strain and shear wave elastography had similar diagnostic performance. The addition of strain and shear wave elastography to B-mode US improved diagnostic performance. The combination of strain and shear wave elastography results in a higher diagnostic yield than each individual elastographic modality.

Differences in drug susceptibility pattern between Mycobacterium avium and Mycobacterium intracellulare isolated in respiratory specimens

Mycobacterium avium complex (MAC) is the most common etiologic organisms of nontuberculous mycobacteria (NTM) lung disease. In this study, we aimed to retrospectively investigate the differences in drug susceptibility patterns of two major MAC species; Mycobacterium avium and Mycobacterium intracellulare. A total of 1883 major two MAC isolates (1060 M. avium and 823 M. intracellulare) from respiratory specimens were included in this study during the period 2011─2016. The minimum inhibitory concentrations (MICs) were determined by broth microdilution method and MIC₅₀/MIC₉₀ values were derived from MIC distribution. M. intracellulare had generally low susceptible rates than M. avium for almost all tested antimicrobials except ethambutol and amikacin. The susceptible rate to clarithromycin was >94% of the MAC without significant differences between the two species. The MIC₅₀ values of ciprofloxacin, clarithromycin, linezolid, moxifloxacin, and rifampicin were higher in M. intracellulare than in M. avium, contrary to the results of ethambutol with a higher MIC₅₀ in M. avium. In general, M. intracellulare showed a higher resistance rate and higher MIC₅₀ values than M. avium. Differences between this study and previous reports suggest regional differences in drug susceptibility profile of MAC species.

Vascular Ehlers-Danlos syndrome with cryptorchidism, recurrent pneumothorax, and pulmonary capillary hemangiomatosis-like foci: A case report

RATIONALE

Vascular Ehlers-Danlos syndrome (vEDS) is a rare autosomal dominant inherited collagen disorder caused by defects or deficiency of pro-alpha 1 chain of type III procollagen encoded by COL3A1. vEDS is characterized not only by soft tissue manifestations including hyperextensibility of skin and joint hypermobility but also by early mortality due to rupture of arteries or vital organs. Although pulmonary complications are not common, vEDS cases complicated by pneumothorax, hemothorax, or intrapulmonary hematoma have been reported. When a patient initially presents only with pulmonary complications, it is not easy for clinicians to suspect vEDS.

PATIENT CONCERNS

We report a case of an 18-year-old high school student, with a past history of cryptorchidism, presenting with recurrent pneumothorax.

DIAGNOSES

Routine laboratory findings were unremarkable. Chest high resolution computed tomographic scan showed age-unmatched hyperinflation of both lungs, atypical cystic changes and multifocal ground glass opacities scattered in both lower lobes. His slender body shape, hyperflexible joints, and hyperextensible skin provided clue to suspicion of a possible connective tissue disorder.

INTERVENTIONS

The histological examination of the lung lesions showed excessive capillary proliferation in the pulmonary interstitium and pleura allowing the diagnosis of pulmonary capillary hemangiomatosis (PCH)-like foci. Genetic study revealed COL3A1 gene splicing site mutation confirming his diagnosis as vEDS.

OUTCOMES

Although his diagnosis vEDS is notorious for fatal vascular complication, there was no evidence of such complication at presentation. Fortunately, he has been followed up for 10 months without pulmonary or vascular complications.

LESSONS

To the best of our knowledge, both cryptorchidism and PCH-like foci have never been reported yet as complications of vEDS, suggesting our case might be a new variant of this condition. This case emphasizes the importance of comprehensive physical examination and history-taking, and the clinical suspicion of a possible connective tissue disorder when we encounter cases with atypical presentation and/or unique chest radiologic findings especially in young patients.

Efficacy and Safety of Ethanol Ablation for Branchial Cleft Cysts

BACKGROUND AND PURPOSE

Branchial cleft cyst is a common congenital lesion of the neck. This study evaluated the efficacy and safety of ethanol ablation as an alternative treatment to surgery for branchial cleft cyst.

MATERIALS AND METHODS

Between September 2006 and October 2016, ethanol ablation was performed in 22 patients who refused an operation for a second branchial cleft cyst. After the exclusion of 2 patients who were lost to follow-up, the data of 20 patients were retrospectively evaluated. All index masses were confirmed as benign before treatment. Sonography-guided aspiration of the cystic fluid was followed by injection of absolute ethanol (99%) into the lesion. The injected volume of ethanol was 50%-80% of the volume of fluid aspirated. Therapeutic outcome, including the volume reduction ratio, therapeutic success rate (volume reduction ratio of >50% and/or no palpable mass), and complications, was evaluated.

RESULTS

The mean index volume of the cysts was 26.4 ± 15.7 mL (range, 3.8-49.9 mL). After ablation, the mean volume of the cysts decreased to 1.2 ± 1.1 mL (range, 0.0-3.5 mL). The mean volume reduction ratio at last follow-up was 93.9% ± 7.9% (range, 75.5%-100.0%; P < .001). Therapeutic success was achieved in all nodules (20/20, 100%), and the symptomatic (P < .001) and cosmetic (P < .001) scores had improved significantly by the last follow-up. In 1 patient, intracystic hemorrhage developed during the aspiration; however, no major complications occurred in any patient.

CONCLUSIONS

Ethanol ablation is an effective and safe treatment for patients with branchial cleft cysts who refuse, or are ineligible for, an operation.

Epidemiology and Clinical Characteristics of Zika Virus Infections Imported into Korea from March to October 2016

Zika is a re-emerging, mosquito-borne viral infection, which has been recently shown to cause microcephaly and Guillain-Barré syndrome. Since 2015 the number of infected patients has increased significantly in South America. The purpose of this study was to identify the epidemiologic and clinical characteristics of patients with Zika virus (ZIKV) infections in Korea. Patients who had visited areas of risk and tested positive in the ZIKV reverse transcriptase polymerase chain reaction (RT-PCR) in blood, urine, or saliva specimens were included. The first Korean case of ZIKV infection was reported in March 2016, and 14 cases had been reported by October 2016. The median age of the patients was 34 years (19-64 years). Ten patients had been exposed in Southeast Asia and 4 in Latin America. Rash was the most common symptom (92.9%; 13/14), followed by myalgia (50.0%; 7/14), and arthralgia (28.6%, 4/14). There were no neurologic abnormalities and none of the patients was pregnant. Results of biochemical tests were normal. Positivity rates of RT-PCR for ZIKV in serum, urine, and saliva were 53.8%, 100.0%, and 83.3%, respectively in the first week of symptoms. In conclusion, 14 patients with ZIKV infections were reported in Korea by October 2016 and all of them had mild clinical symptoms.

Improvement in Ventilation-Perfusion Mismatch after Bronchoscopic Lung Volume Reduction: Quantitative Image Analysis

Purpose To evaluate whether bronchoscopic lung volume reduction (BLVR) increases ventilation and therefore improves ventilation-perfusion (V/Q) mismatch. Materials and Methods All patients provided written informed consent to be included in this study, which was approved by the Institutional Review Board (2013-0368) of Asan Medical Center. The physiologic changes that occurred after BLVR were measured by using xenon-enhanced ventilation and iodine-enhanced perfusion dual-energy computed tomography (CT). Patients with severe emphysema plus hyperinflation who did not respond to usual treatments were eligible. Pulmonary function tests, the 6-minute walking distance (6MWD) test, quality of life assessment, and dual-energy CT were performed at baseline and 3 months after BLVR. The effect of BLVR was assessed with repeated-measures analysis of variance. Results Twenty-one patients were enrolled in this study (median age, 68 years; mean forced expiratory volume in 1 second [FEV₁], 0.75 L ± 0.29). After BLVR, FEV₁ (P < .001) and 6MWD (P = .002) improved significantly. Despite the reduction in lung volume (-0.39 L ± 0.44), both ventilation per voxel (P < .001) and total ventilation (P = .01) improved after BLVR. However, neither perfusion per voxel (P = .16) nor total perfusion changed significantly (P = .49). Patients with lung volume reduction of 50% or greater had significantly better improvement in FEV₁ (P = .02) and ventilation per voxel (P = .03) than patients with lung volume reduction of less than 50%. V/Q mismatch also improved after BLVR (P = .005), mainly owing to the improvement in ventilation. Conclusion The dual-energy CT analyses showed that BLVR improved ventilation and V/Q mismatch. This increased lung efficiency may be the primary mechanism of improvement after BLVR, despite the reduction in lung volume. ^© RSNA, 2017 Online supplemental material is available for this article.

Integrin α1β1 protects against signs of post-traumatic osteoarthritis in the female murine knee partially via regulation of epidermal growth factor receptor signalling

OBJECTIVE

To investigate the role of integrin α1β1 in the progression of post-traumatic osteoarthritis (PTOA), and elucidate the contribution of epidermal growth factor receptor (EGFR) signalling to the mechanism by which integrin α1β1 might control PTOA. We hypothesised that integrin α1β1 plays a protective role in the course of PTOA and that the effect of PTOA (e.g., synovitis, loss of cartilage and growth of osteophytes) would be exacerbated in mice lacking integrin α1β1 at every time point post destabilisation of medial meniscus (DMM).

METHODS

DMM or sham surgery was performed on integrin α1-null and wild type (WT) mice and the progression of PTOA analysed at 2, 4, 8 and 12 weeks post-surgery (PS) using micro-computed tomography (microCT), histology, and immunohistochemistry. In addition, the effects of EGFR blockade were examined by treating the mice with the EGFR inhibitor erlotinib.

RESULTS

Integrin α1-null female, but not male, mice showed earlier cartilage degradation post DMM surgery compared to WT controls. Furthermore, erlotinib treatment resulted in significantly less cartilage damage in integrin α1-null but not WT mice. Independent of genotype, erlotinib treatment significantly mitigated the effects of PTOA on many tissues of female mice including meniscal and fabella bone volume, subchondral bone thickness and density and cartilage degradation. In contrast, reduced EGFR signalling had little effect on signs of PTOA in male mice.

CONCLUSION

Integrin α1β1 protects against PTOA-induced cartilage degradation in female mice partially via the reduction of EGFR signalling. Furthermore, reduction of EGFR signalling protects against the development of PTOA in female, but not male mice.

Comparisons of clinical outcomes in patients with and without a preoperative tissue diagnosis in the persistent malignant-looking, ground-glass-opacity nodules

To evaluate the clinical usefulness of surgical resection of persistent malignant-looking ground-glass-opacity nodules (GGN) without a preoperative tissue diagnosis.From September 1998 to November 2011, we retrospectively enrolled 288 patients (126 men, 162 women; mean age, 59.3 years) with lung adenocarcinoma proven by surgery and which appeared as GGN on chest computed tomography (CT, ground-glass-opacity [GGO] proportion >20%). We divided the study subjects into 2 groups: patients with a preoperative tissue diagnosis (PTD group, n = 207) and patients without a preoperative tissue diagnosis (No-PTD group, n = 81). In patients with GGN having GGO ≥ 90% (n = 140), we divided them into 2 groups: PTD group (n = 83) and No-PTD group (n = 57). The clinical and surgical outcomes were compared between the 2 groups.In 204 patients who underwent lobectomy for stage Ia lung cancer, there was no significantly different recurrence-free survival between the 2 groups (P = 0.721). A significantly lower percentage of No-PTD group waited >14 days for surgery (77.8% vs 87.9%, P = 0.030) and were hospitalized for >7 days (56.8% vs 89.9%, P < 0.001). They showed a shorter mean surgery time (136.9 vs 155.0 minutes, P = 0.019). In patients with GGN having GGO ≥ 90%, the results were the same as those of all of the study subjects.No-PTD group can gain benefits perioperatively, showing no different recurrence-free survival with PTD group in stage Ia lung cancer.

Comparative Analysis of Liver Injury-Associated Cytokines in Acute Hepatitis A and B

PURPOSE

Acute hepatitis A (AHA) and acute hepatitis B (AHB) are caused by an acute infection of the hepatitis A virus and the hepatitis B virus, respectively. In both AHA and AHB, liver injury is known to be mediated by immune cells and cytokines. In this study, we measured serum levels of various cytokines and T-cell cytotoxic proteins in patients with AHA or AHB to identify liver injury-associated cytokines.

MATERIALS AND METHODS

Forty-six patients with AHA, 16 patients with AHB, and 14 healthy adults were enrolled in the study. Serum levels of 17 cytokines and T-cell cytotoxic proteins were measured by enzyme-linked immunosorbent assays or cytometric bead arrays and analyzed for correlation with serum alanine aminotransferase (ALT) levels.

RESULTS

Interleukin (IL)-18, IL-8, CXCL9, and CXCL10 were significantly elevated in both AHA and AHB. IL-6, IL-22, granzyme B, and soluble Fas ligand (sFasL) were elevated in AHA but not in AHB. In both AHA and AHB, the serum level of CXCL10 significantly correlated with the peak ALT level. Additionally, the serum level of granzyme B in AHA and the serum level of sFasL in AHB correlated with the peak ALT level.

CONCLUSION

We identified cytokines and T-cell cytotoxic proteins associated with liver injury in AHA and AHB. These findings deepen the existing understanding of immunological mechanisms responsible for liver injury in acute viral hepatitis.

Recent update in HIV vaccine development

Despite the tremendous efforts to develop a successful human immunodeficiency virus (HIV) vaccine, the quest for a safe and effective HIV vaccine seems to be remarkably long and winding. Disappointing results from previous clinical trials of VaxGen's AIDSVAXgp120 vaccine and MRKAd5 HIV-1 Gag/Pol/Nef vaccine emphasize that understanding the correlates of immune protection in HIV infection is the key to solve the puzzle. The modest vaccine efficacy from RV144 trial and the successive results obtained from the correlate of risk analysis have reinvigorated the HIV vaccine research field leading to various novel strategies. This paper will review the brief history and recent advances in HIV vaccine development.

Evaluation of Mediastinal Lymph Nodes in Sarcoidosis, Sarcoid Reaction, and Malignant Lymph Nodes Using CT and FDG-PET/CT

The aim of this study was to analyze the clinical, computed tomography (CT), and positron emission tomography (PET) findings of sarcoidosis, sarcoid reaction, and malignant lymph nodes (LNs) to the results of transbronchial LN aspiration and biopsy (TBNA).The TBNA results of mediastinal and hilar LNs of 152 patients in our hospital from July 2008 to March 2013 were retrospectively reviewed. Two independent radiologists measured the size and attenuation of LNs on CT and assessed the probability of the 3 categories: sarcoidosis (n = 36), sarcoid reaction (n = 25), or malignant LNs (n = 91). The total volume and attenuation of LNs were measured using Image J (NIH). The median maximum standardized uptake value (maxSUV) of the 3 mediastinal and hilar LNs on PET/CT was obtained.There was no significantly different CT finding between sarcoidosis and sarcoid reaction. Multivariate analysis showed that the age, total volume of LNs, and number of enlarged LNs significantly differed between sarcoid reaction and malignant LNs. Sarcoid reaction tends to be occurred in young patients (P = 0.007), the total volume of LNs was smaller (P = 0.04) than that of malignant LNs, and there were significantly more LNs >1 cm (P = 0.005). The median maxSUV of the 3 highest SUVs of the LNs did not significantly differ between the 3 entities.

Effects of Feeding Barley Naturally Contaminated with Fusarium Mycotoxins on Growth Performance, Nutrient Digestibility, and Blood Chemistry of Gilts and Growth Recoveries by Feeding a Non-contaminated Diet

The objectives of this study were to investigate the effects of feeding barley naturally contaminated with Fusarium mycotoxins on growth performance, vulva swelling, and digestibility of dry matter, organic matter, and crude protein of gilts and the recovery of gilts fed normal diets immediately after the exposure to contaminated diets by measuring growth performance and vulva swelling. In Exp. 1, four diets were prepared to contain 0%, 15%, 30%, or 45% contaminated barley containing 25.7 mg/kg deoxynivalenol and 26.0 μg/kg zearalenone. Sixteen gilts with an initial body weight (BW) of 33.3 kg (standard deviation = 3.0) were individually housed in a metabolism crate and assigned to 4 diets with 4 replicates in a randomized complete block design based on BW. During the 14-d feeding trial, individual BW and feed consumption were measured weekly and the vertical and horizontal lengths of vulva were measured every 3 d. From d 10, feces were collected by the maker-to-marker method for 4 d. Blood samples were collected on d 14. During the overall period, the average daily gain, average daily feed intake, and gain:feed of pigs linearly decreased (p<0.01) as the dietary concentration of contaminated barley increased. However, the digestibility of crude protein was linearly increased (p = 0.011) with the increasing amounts of contaminated barley. Increasing dietary Fusarium mycotoxin concentrations did not influence vulva size, blood characteristic as well as immunoglobulin level of pigs. In the Exp. 2, a corn-soybean meal-based diet was formulated as a recovery diet. Pigs were fed the recovery diet immediately after completion of the Exp. 1. During the 14-d of recovery period, the individual BW and feed consumption were measured weekly and the vertical and horizontal length of vulva were measured every 3 d from d 0. On d 7, the feed intake of pigs previously fed contaminated diets already reached that of pigs fed a diet with 0% contaminated barley and no significant difference in growth performance among treatments was observed during d 7 to 14 of the recovery period. In conclusion, increasing levels of mycotoxins in diets linearly decreased the growth performance of pigs, and these damages can be recovered in 7 d after the diet was replaced with a normal diet. The vulva size, blood characteristic, immune responses were not affected by increasing level of contaminated barley in the diets fed to pigs.

Pulmonary sclerosing pneumocytoma of the lung: CT characteristics in a large series of a tertiary referral center

The purpose of this study is to describe the detailed clinical, chest computed tomography (CT), and F-fluorodeoxyglucose positron emission tomography (FDG PET) characteristics of the tumor boundary for the diagnosis and investigate the outcome of pulmonary sclerosing pneumocytoma (PSP) using confirmed large data of a tertiary referral center. Confirmed 76 patients were included. We evaluated the findings of CT including 4 CT signs, FDG PET, and histopathology. Most patients had a single lesion (92.1%), smooth boundary (65.8%), and oval shape (65.8%) and the mean diameter was 22.7 mm. The CT signs included marginal pseudocapsule (50%), overlying vessel (26.3%), air gap (2.6%), and halo sign (17.1%). A predominantly solid was the most common histopathologic type. The mean maximum standardized uptake value on FDG PET of 17 patients was 1.8 (range, near 0 or normal tissue metabolism ∼2.9). PSP should be considered in middle-aged women whose CT features show incidental nodule(s), commonly with surrounding ground-glass opacity and characteristic CT signs of the tumor boundary, and hypometabolic uptake on FDG PET. Outcome of patients is excellent.

Total Solution Synthesis of Human Epidermal Growth Factor (h-EGF) by the Assembly of Nine Building Blocks

Human epidermal growth factor (h-EGF) composed of 53 amino acids bearing three intramolecular disulfide bridges was synthesized by the maximum protecting solution method. The synthetic h-EGF coincided with recombinant h-EGF by reverse-phase HPLC, and the sites of three intramolecular disulfide bridges were ascertained by a thermolytic digestion. The synthetic h-EGF possessed m/z 6215.7 in its FAB-MS as expected, and exhibited compatible mitogenic activity.