Persistent Positive Real-Time Reverse Transcription Polymerase Chain Reaction (RT-PCR) Results in Recovered COVID-19 Hospital Patients: Implications for Interpretation

Background Real-time reverse transcription polymerase chain reaction (RT-PCR) test results often remain positive in patients with COVID-19, even after their symptoms have improved. We compared the characteristics of patients with persistently positive RT-PCR test results despite improved COVID-19 symptoms to those whose RT-PCR test results turned negative following symptom improvement. Materials and methods A total of 143 adult patients with COVID-19 who were hospitalized at a tertiary university hospital were enrolled. Demographic, clinical, treatment, and epidemiological data were extracted from their electronic medical records. These data were compared between patients with persistently positive RT-PCR test results and those with negative RT-PCR test results after symptom improvement. Results The prevalence of cough and respiratory symptoms was less in COVID-19 patients with persistently positive RT-PCR test results after symptom improvement than in other patients with COVID-19 (p<0.05). Conclusion Persistently positive patients had a lower prevalence of cough than those who became negative. None of the other examined co-variates (hypertension, chronic kidney disease, chronic lung disease, dyslipidemia, etc.) was associated with the persistent positivity.

Coinfection With Severe Fever With Thrombocytopenia Syndrome and Scrub Typhus in Korea

Background

Scrub typhus and severe fever with thrombocytopenia syndrome (SFTS) are the 2 most common tick-borne infectious diseases in Korea. Every year, an increasing number of cases are reported, which is a public health concern. Therefore, we aimed to investigate the prevalence of SFTS-scrub typhus coinfection in patients with SFTS.

Methods

Clinical samples were collected from 129 patients with SFTS. One-step reverse-transcription polymerase chain reaction (PCR) was performed to identify the SFTS virus (SFTSV), and real-time PCR followed by nested PCR was performed to detect the Orientia tsutsugamushi gene for scrub typhus. Phylogenetic analysis was conducted to confirm the evolutionary relationships among different species.

Results

Among 129 SFTS cases, 2 patients with SFTSV were positive for O. tsutsugamushi with a prevalence of coinfection of 1.6% (95% confidence interval, .001-.06). Phylogenetic analysis confirmed these as O. tsutsugamushi strain Boryong.

Conclusions

Our study found that 1.6% of patients were coinfected with SFTS and scrub typhus infection. We believe that this information will add a new dimension to clinical diagnosis, which should be considered for better public health management. Further research is needed to better understand the ecological transmission dynamics and geographical distribution of SFTSV and O. tsutsugamushi in endemic countries.

Carbapenem Use in the Last Days of Life: A Nationwide Korean Study

The appropriate use of carbapenem is a critical concern for patient safety and public health, and is a national priority. We investigated the nationwide status of carbapenem prescription in patients within their last 14 days of life to guide judicious-use protocols from the previous study comprised of 1350 decedents. Carbapenem use was universally controlled through computerised authorisation system at all centres during the study period. Carbapenem prescribing patterns and their optimality were evaluated. A total of 1201 patients received antimicrobial agents within the last two weeks of their lives, of whom 533 (44.4%) received at least one carbapenem. The median carbapenem treatment duration was seven days. Of the 533 patients receiving carbapenems, 510 (95.7%) patients had microbiological samples drawn and 196 (36.8%) yielded carbapenem-resistant pathogens. A total of 200 (37.5%) patients were referred to infectious disease (ID) specialists. Of the 333 patients (62.5%) who did not have ID consultations, 194 (58.2%) were assessed as "not optimal", 79 (23.7%) required escalation, 100 (30.0%) required de-escalation, and 15 (4.5%) were discontinued. Notwithstanding the existing antibiotic restriction program system, carbapenems are commonly prescribed to patients in their last days of life.

Clinically differential diagnosis of human granulocytic anaplasmosis and severe fever with thrombocytopenia syndrome

This study analyzed HGA and SFTS in patients with suspected tick-borne infection by focusing on key differences that clinicians can easily recognize. A retrospective analysis was performed on confirmed patients with HGA or SFTS in 21 Korean hospitals from 2013 to 2020. A scoring system was developed by multivariate regression analysis and accuracy assessment of clinically easily discriminable parameters was performed. The multivariate logistic regression analysis revealed that sex (especially male sex) (odds ratio [OR] 11.45, P = 0.012), neutropenia (< 1500) (OR 41.64, P < 0.001), prolonged activated partial thromboplastin time (OR 80.133, P < 0.001), and normal C-reactive protein concentration (≤ 1.0 mg/dL; OR 166.855, P = 0.001) were significantly associated with SFTS but not with HGA. Each factor, such as meaningful variables, was given 1 point, and a receiver-operating characteristic curve with a cutoff value (> 1) in a 5-point scoring system (0-4 points) was analyzed to evaluate the accuracy of differentiation between HGA and SFTS. The system showed 94.5% sensitivity, 92.6% specificity, and an area under the receiver-operating characteristic curve of 0.971 (0.949-0.9). Where HGA and SFTS are endemic, the scoring system based on these four parameters such as sex, neutrophil count, activated partial thromboplastin time, and C-reactive protein concentration will facilitate the differential diagnosis of HGA and SFTS in the emergency room in patients with suspected tick-borne infectious diseases.

Use of Antibiotics Within the Last 14 Days of Life in Korean Patients: A Nationwide Study

BACKGROUND

Antimicrobial prescriptions for serious chronic or acute illness nearing its end stages raise concerns about the potential for futile use, adverse events, increased multidrug-resistant organisms, and significant patient and social cost burdens. This study investigated the nationwide situation of how antibiotics are prescribed to patients during the last 14 days of life to guide future actions.

METHODS

This nationwide multicenter retrospective cohort study was conducted at 13 hospitals in South Korea from November 1 to December 31, 2018. All decedents were included in the study. Antibiotic use during the last two weeks of their lives was investigated.

RESULTS

A total of 1,201 (88.9%) patients received a median of two antimicrobial agents during the last two weeks of their lives. Carbapenems were prescribed to approximately half of the patients (44.4%) in the highest amount (301.2 days of therapy per 1,000 patient-days). Among the patients receiving antimicrobial agents, 63.6% were inappropriate and only 327 patients (27.2%) were referred by infectious disease specialists. The use of carbapenem (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.13-2.03; P = 0.006), underlying cancer (OR, 1.56; 95% CI, 1.20-2.01, P = 0.047), underlying cerebrovascular disease (OR, 1.88; 95% CI, 1.23-2.89, P = 0.004), and no microbiological testing (OR, 1.79; 95% CI, 1.15-2.73; P = 0.010) were independent predictors for inappropriate antibiotic prescribing.

CONCLUSION

A considerable number of antimicrobial agents are administered to patients with chronic or acute illnesses nearing their end-of-life, a high proportion of which are prescribed inappropriately. Consultation with an infectious disease specialist, in addition to an antimicrobial stewardship program, may be necessary to induce the optimal use of antibiotics.

Healthcare Workforce Response to The Coronavirus Disease Outbreak in Daegu, Korea: A Multi-Center, Cross-Sectional Survey

BACKGROUND

Securing an available healthcare workforce is critical to respond to coronavirus disease 2019 (COVID-19); however, research investigating Korea's COVID-19 staffing response is rare. To present the fundamental data of healthcare staff in response to the surge in COVID-19 cases, we investigated the healthcare workforce response in Daegu, South Korea, which experienced the first largest outbreak of COVID-19 outside of China.

MATERIALS AND METHODS

In response to the COVID-19 outbreak, this retrospective cross-sectional study analyzed data on the scale and characteristics of healthcare workers (HCWs). Additionally, it analyzed the clinical and epidemiological characteristics of HCWs infected with COVID-19 in six major teaching hospitals (five tertiary and one secondary) in Daegu from January 19 to April 30, 2020.

RESULTS

During this study period, only 1.3% (n = 611) of the total hospitalized patients (n = 48,807) were COVID-19 inpatients, but they occupied 6.0% (n = 303) of the total hospital beds (n = 5,056), and 23.7% (n = 3,471) of all HCWs (n = 14,651) worked in response to COVID-19. HCWs participating in COVID-19-related works comprised 50.6% (n = 1,203) of doctors (n = 2,379), 26.3% (n = 1,571) of nurses (n = 5,982), and 11.4% (n = 697) of other HCWs (n = 6,108). Only 0.3% (n = 51) of HCWs (n = 14,651) developed COVID-19 infections from community-acquired (66.7%) or hospital-acquired (29.4%). Nurses were affected predominantly (33.3%), followed by doctors (9.8%), caregivers (7.8%), radiographers (5.9%), and others (45.1%), including nurse aides and administrative, facility maintenance, telephone appointment centers, and convenience store staff. All HCWs infected with COVID-19 recovered completely. The 32.7% (n = 333) of individuals (n = 1,018) exposed to HCWs who had COVID-19 were quarantined, and only one case of secondary transmission among them occurred.

CONCLUSION

The COVID-19 pandemic has necessitated significant staffing and facility usage, which is disproportionate to the relatively low number of COVID-19 inpatients, imposing a substantial burden on healthcare resources. Therefore, beyond the current reimbursement level of the Korean National Health Insurance, a new type of rewarding system is needed to prepare hospitals for the emerging outbreaks of infectious diseases. Keeping HCWs safe from COVID-19 is crucial for maintaining the healthcare workforce during a sudden massive outbreak. Further studies are needed to determine the standards of required HCWs through detailed research on the working hours and intensity of HCWs responding to COVID-19.

Usefulness of ELISA Using Total Antibody against Plant-Expressed Recombinant Nucleocapsid Protein of SARS-CoV-2

Here, we aimed to investigate the diagnostic value of a serological assay using the nucleocapsid protein developed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection and evaluated its performance using three commercial enzyme-linked immunosorbent assays (ELISAs), namely, Standard E 2019 novel coronavirus disease (COVID-19) total antibody (Ab) ELISA (SD Biosensor), and EDI novel coronavirus COVID-19 IgG and IgM ELISA. A recombinant nucleocapsid protein (rNP) was expressed from plants and Escherichia coli for the detection of serum total Ab. We prospectively collected 141 serum samples from 32 patients with reverse transcription-PCR (RT-PCR)-confirmed COVID-19 and determined the sensitivity and dynamics of their total Ab response. Specificity was evaluated using 158 prepandemic samples. To validate the assays, we evaluated the performance using two different cutoff values. The sensitivity and specificity for each assay were as follows: 92.91% and 94.30% (plant-rNP), 83.69% and 98.73% (SD Biosensor), 75.89% and 98.10% (E. coli-rNP), 76.47% and 100% (EDI-IgG), and 80.39% and 80% (EDI-IgM). The plant-based rNP showed the highest sensitivity and area under the receiver operating characteristic (ROC) curve (0.980) among all the assays (P < 0.05). The seroconversion rate for total Ab increased sequentially with disease progression, with a sensitivity of 100% after 10 to 12 days of post-symptom onset (PSO) for both rNP-plant-based and SD Biosensor ELISAs. After 2 weeks of PSO, the seroconversion rates were >80% and 100% for EDI-IgM and EDI-IgG ELISA, respectively. Seroconversion occurred earlier with rNP plant-based ELISA (5 days PSO) compared with E. coli-based (7 days PSO) and SD Biosensor (8 days PSO) ELISA. We determined that rNP produced in plants enables the robust detection of SARS-CoV-2 total Abs. The assay can be used for serosurvey and complementary diagnosis of COVID-19. IMPORTANCE At present, the principal diagnostic methods for COVID-19 comprise the identification of viral nucleic acid by genetic approaches, including PCR-based techniques or next-generation sequencing. However, there is an urgent need for validated serological assays which are crucial for the understanding of immune responses against SARS-CoV-2. In this study, a highly sensitive and specific serological antibody assay was developed for the detection of SARS-CoV-2 with an overall accuracy of 93.56% using a recombinant nucleoprotein expressed from plants.

Clinical impact of blood pressure variability in patients with COVID-19 and hypertension

OBJECTIVE

This study aimed to investigate the relationship between blood pressure variability (BPV) and clinical outcomes in patients with coronavirus disease 2019 (COVID-19) and hypertension.

METHODS

A total of 136 patients hospitalized with COVID-19 were enrolled in this study. Patients were grouped according to the presence of hypertension and BPV. Mean arterial pressure (MAP) measured at 8 a.m. and 8 p.m. was analyzed, and BPV was calculated as the coefficient of variation of MAP (MAPCV). High BPV was defined as MAPCV values above the median. We compared the age, level of C-reactive protein (CRP), creatine kinase-MB (CK-MB), N-terminal pro-B type natriuretic peptide (NT-proBNP), creatinine and in-hospital mortality and investigated the relationship among the groups.

RESULTS

COVID-19 patients with hypertension were older (70 ± 12 vs. 53 ± 17 years; P < 0.001), had higher levels of CRP (9.4 ± 9.2 vs. 5.3 ± 8.2 mg/dL; P = 0.009), MAPCV (11.4 ± 4.8 vs. 8.9 ± 3.2; P = 0.002), and higher in-hospital mortality (19.6% vs. 5.9%; P = 0.013) than those without hypertension. There was a proportional relationship between BPV and age, levels of CRP, CK-MB, NT-proBNP, creatinine and in-hospital mortality (all, P < 0.05). In Cox regression analysis, advanced age [≥80 years, hazard ratio (HR) 10.4, 95% confidence interval (CI) 2.264-47.772, P = 0.003] and higher MAPCV (HR 1.617, 95% CI, 1.281-2.040, P < 0.001) were significantly associated with in-hospital mortality.

CONCLUSION

High BPV in COVID-19 patients with hypertension is significantly associated with in-hospital mortality. Advanced age and systemic inflammation are proportional to high BPV. Additional attention is needed for COVID-19 patients with hypertension and high BPV.

Comparison of RT-PCR, RT-nested PCRs, and real-time PCR for diagnosis of severe fever with thrombocytopenia syndrome: a prospective study

We designed a highly sensitive reverse transcription nested polymerase chain reaction targeting the M-segment (NPCR-M) of severe fever with thrombocytopenia syndrome (SFTS) virus. NPCR-M was performed in parallel with three other referenced PCR assays QPCR-S, PCR-M, and NPCR-S to assess their clinical usefulness as routine diagnostic techniques for SFTS. In this multi-centered prospective study, 122 blood samples from 38 laboratory-confirmed SFTS patients and 85 control samples were used. The results demonstrated that QPCR-S and NPCR-S had better sensitivity rate up to 21 days after symptom onset however, the PCR-M showed poor sensitivity after 7 days of symptom onset. Our designed NPCR-M had a higher detection rate up to 40 days from symptom onset and revealed the persistence of SFTSV RNA in the early convalescent phase. No false-positive results were seen for the control samples. Additionally, NPCR-M showed positive results for a sample that initially showed negative results from other PCRs and for many other samples collected in the convalescent phase of SFTS. Our designed nested PCR is suitable for SFTSV detection in patients’ blood collected in the acute and early convalescent phase of SFTS, and shows better sensitivity and high specificity even up to 40 days after symptom onset.

Prospective evaluation of dietary and lifestyle pattern indices with risk of colorectal cancer in a cohort of younger women

BACKGROUND

Although colorectal cancer (CRC) incidence in the USA is declining overall, its incidence is increasing among those younger than 50 years of age. The reasons underlying the increasing trend are largely unknown, although behavioral changes, such as unhealthy diet and lifestyle factors, may be partially responsible.

DESIGN

A prospective cohort study included 94 217 women aged 26-45 years at baseline. Validated anthropometric measures and lifestyle information were self-reported biennially. Exposures were four recommendation-based dietary indices-the prime diet quality score and three plant-based dietary indices; and two mechanism-based indices-the empirical dietary and lifestyle index for hyperinsulinemia (EDIH and ELIH). We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for overall CRC and for early-onset (before age 50) and after age 50 CRC separately.

RESULTS

We documented 332 cases of CRC during 24 years of follow-up (2 113 655 person-years), with an average age of 52 ± 7 years at diagnosis. Hyperinsulinemic dietary and lifestyle patterns were associated with a higher risk of CRC. Multivariable-adjusted HRs (95% CIs) comparing participants in the highest versus lowest quartile were: 1.67 for EDIH (95% CI: 1.15-2.44, P-trend = 0.01) and 1.51 for ELIH (95% CI: 1.10-2.08, P-trend = 0.01). Moreover, per 75% increment in rank, ELIH appeared to be a stronger risk factor for early-onset CRC (HR = 1.86, 95% CI: 1.12-3.07) than after age 50 CRC (HR = 1.20, 95% CI: 0.83-1.73, P-heterogeneity = 0.16). The four recommendation-based indices were not significantly associated with overall, early-onset, or after age 50 CRC risk (per 75% increment in rank, HRs ranged from 0.75 to 1.28).

CONCLUSION

Dietary and lifestyle patterns contributing to hyperinsulinemia were associated with greater CRC risk in younger women. Moreover, the hyperinsulinemic lifestyle showed a suggestively stronger positive association with early-onset CRC risk, compared with after age 50 CRC. Our findings suggest that dietary and lifestyle interventions to reduce insulinemic potential may be effective for CRC prevention among younger women.

Effects of steroid therapy in patients with severe fever with Thrombocytopenia syndrome: A multicenter clinical cohort study

BACKGROUND

Severe fever with thrombocytopenia syndrome (SFTS) is an acute, febrile, and potentially fatal tick-borne disease caused by the SFTS Phlebovirus. Here, we evaluated the effects of steroid therapy in Korean patients with SFTS.

METHODS

A retrospective study was performed in a multicenter SFTS clinical cohort from 13 Korean university hospitals between 2013 and 2017. We performed survival analysis using propensity score matching of 142 patients with SFTS diagnosed by genetic or antibody tests.

RESULTS

Overall fatality rate was 23.2%, with 39.7% among 58 patients who underwent steroid therapy. Complications were observed in 37/58 (63.8%) and 25/83 (30.1%) patients in the steroid and non-steroid groups, respectively (P < .001). Survival analysis after propensity score matching showed a significant difference in mean 30-day survival time between the non-steroid and steroid groups in patients with a mild condition [Acute Physiology and Chronic Health Evaluation II (APACHE II) score <14; 29.2 (95% CI 27.70-30.73] vs. 24.9 (95% CI 21.21-28.53], P = .022]. Survival times for the early steroid (≤5 days from the start of therapy after symptom onset), late steroid (>5 days), and non-steroid groups, were 18.4, 22.4, and 27.3 days, respectively (P = .005).

CONCLUSIONS

After steroid therapy, an increase in complications was observed among patients with SFTS. Steroid therapy should be used with caution, considering the possible negative effects of steroid therapy within 5 days of symptom onset or in patients with mild disease (APACHE II score <14).

The clinical and economic burden of community-onset complicated skin and skin structure infections in Korea

BACKGROUND/AIMS

To investigate epidemiologic characteristics, clinical and economic burdens, and factors associated with mortality in complicated skin and skin structure infection (cSSSI) patients in Korea.

METHODS

A retrospective, observational, nationwide study was conducted between April to July 2012 at 14 tertiary-hospitals in Korea. Eligible patients were hospitalized adults with community acquired cSSSI, who underwent surgical intervention and completed treatment between November 2009 and October 2011. Data on demography, clinical characteristics, outcomes and medical resource utilization were collected through medical record review. Direct medical costs were calculated by multiplying quantities of resources utilized by each unit price in Korea.

RESULTS

Of 473 patients enrolled, 449 patients (except 24 patients with no record on surgical intervention) were eligible for analysis. Microbiological testing was performed on 66.1% of patients and 8.2% had multiple pathogens. Among culture confirmed pathogens (n = 297 patients, 340 episodes), 76.2% were gram-positive (Staphylococcus aureus; 41.2%) and 23.8% were gram-negative. The median duration of hospital stay was 16 days. Among treated patients, 3.3% experienced recurrence and 4.2% died in-hospital. The mean direct medical costs amounted to $4,195/ person, with the greatest expenses for hospitalization and antibiotics. The in-hospital mortality and total medical costs were higher in combined antibiotics therapy than monotherapy (p < 0.05). Charlson's comorbidity index ≥ 3, standardized early warning scoring ≥ 4, sub-fascia infections and combined initial therapy, were all found to be associated with higher mortality.

CONCLUSION

Korean patients with community-onset cSSSI suffer from considerable clinical and economic burden. Efforts should be made to reduce this burden through appropriate initial treatment.

Yeungnam University type drive-through (YU-Thru) coronavirus disease 2019 (COVID-19) screening system: a rapid and safe screening system

Active and prompt scale-up screening tests are essential to efficiently control the coronavirus disease 2019 (COVID-19) outbreak. The goal of this work was to identify shortcomings in the conventional screening system (CSS) implemented in the beginning of the outbreak. To overcome these shortcomings, we then introduced a novel, independently developed system called the Yeungnam University type drive-through (YU-Thru), and distributed it nationwide in Korea. This system is similar to the drive-throughs utilized by fast food restaurants. YU-Thru system has shortened the time taken to test a single person to 2–4 minutes, by completely eliminating the time required to clean and ventilate the specimen collection room. This time requirement was a major drawback of the CSS. YU-Thru system also reduced the risk of subjects and medical staff infecting one another by using a separate and closed examination system. On average, 50 to 60 tests were conducted per day when using the CSS, while now up to 350 tests per day are conducted with the YU-Thru system. We believe that the YU-Thru system has made an important contribution to the rapid detection of COVID-19 in Daegu, South Korea. Here, we will describe the YU-Thru system in detail so that other countries experiencing COVID-19 outbreaks can take advantage of this system.

Chest Computed Tomography Findings in Asymptomatic Patients with COVID-19

Background

Little is known about the damage to the respiratory system in asymptomatic patients with coronavirus disease (COVID-19).

Objective

Herein, we evaluate the findings of chest computed tomography (CT) and radiography in patients with COVID-19 who were asymptomatic.

Methods

We retrospectively investigated patients with a confirmed diagnosis of COVID-19 but who did not show any symptoms. Among the 139 patients with COVID-19 who were hospitalized in Yeungnam University Hopistal in Daegu, South Korea, 10 (7.2%) were asymptomatic. Their chest CT and radiographic findings were analyzed.

Results

In the results, all patients (100%) had ground-glass opacity (GGO) on chest CT. Further, the GGO lesions were predominantly distributed peripherally and posteriorly in all patients. In 9 (90%) patients, the GGO lesions were combined with reticular opacity. Air bronchogram due to bronchiolectasis surrounded by GGO was observed in 8 patients (80%). Additionally, the lung lesions were dominant on the right side in all patients.

Conclusions

In conclusion, considering our results that the lung is affected in asymptomatic patients, it will be necessary to extend the indications of COVID-19 testing for effective management of COVID-19 during the pandemic.

Early Hydroxychloroquine Administration for Rapid Severe Acute Respiratory Syndrome Coronavirus 2 Eradication

There are no proven therapeutics for Coronavirus disease 2019 (COVID-19) pneumonia outbreak. We observed and analyzed the clinical efficacy of the most used hydroxychloroquine (HCQ) for 30 days. In this study, administration of HCQ <5 days from diagnosis (odds ratio: 0.111, 95% confidence interval: 0.034 - 0.367, P = 0.001) was the only protective factor for prolonging of viral shedding in COVID-19 patients. Early administration of HCQ significantly ameliorates inflammatory cytokine secretion by eradicating COVID-19, at discharge. Our findings suggest that patients confirmed of COVID-19 infection should be administrated HCQ as soon as possible.

The Clinical Characteristics and Outcomes of Patients with Moderate-to-Severe Coronavirus Disease 2019 Infection and Diabetes in Daegu, South Korea

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a global pandemic that had affected more than eight million people worldwide by June 2020. Given the importance of the presence of diabetes mellitus (DM) for host immunity, we retrospectively evaluated the clinical characteristics and outcomes of moderate-to-severe COVID-19 in patients with diabetes.

METHODS

We conducted a multi-center observational study of 1,082 adult inpatients (aged ≥18 years) who were admitted to one of five university hospitals in Daegu because of the severity of their COVID-19-related disease. The demographic, laboratory, and radiologic findings, and the mortality, prevalence of severe disease, and duration of quarantine were compared between patients with and without DM. In addition, 1:1 propensity score (PS)-matching was conducted with the DM group.

RESULTS

Compared with the non-DM group (n=847), patients with DM (n=235) were older, exhibited higher mortality, and required more intensive care. Even after PS-matching, patients with DM exhibited more severe disease, and DM remained a prognostic factor for higher mortality (hazard ratio, 2.40; 95% confidence interval, 1.38 to 4.15). Subgroup analysis revealed that the presence of DM was associated with higher mortality, especially in older people (≥70 years old). Prior use of a dipeptidyl peptidase-4 inhibitor or a renin-angiotensin system inhibitor did not affect mortality or the clinical severity of the disease.

CONCLUSION

DM is a significant risk factor for COVID-19 severity and mortality. Our findings imply that COVID-19 patients with DM, especially if elderly, require special attention and prompt intensive care.

Prognostic Accuracy of the SIRS, qSOFA, and NEWS for Early Detection of Clinical Deterioration in SARS-CoV-2 Infected Patients

BACKGROUND

The case fatality rate of coronavirus disease 2019 (COVID-19) is estimated to be between 4.3% and 11.0%. Currently there is no effective antiviral treatment for COVID-19. Thus, early recognition of patients at high risk is important.

METHODS

We performed a retrospective observational study of 110 patients with severe acute respiratory syndrome coronavirus 2 infection. We compared the effectiveness of three scoring systems: the Systemic Inflammatory Response Syndrome (SIRS), quick Sequential Organ Failure Assessment (qSOFA), and National Early Warning Score (NEWS) systems, for predicting the prognosis of COVID-19. The area under the receiver operating characteristic curve (AUROC) was used for these assessments, and Kaplan-Meier survival curves were used to identify the cumulative risk for 28-day mortality according to the NEWS stratification.

RESULTS

For predicting 28-day mortality, NEWS was superior to qSOFA (AUROC, 0.867 vs. 0.779, P < 0.001), while there was no significant difference between NEWS and SIRS (AUROC, 0.867 vs. 0.639, P = 0.100). For predicting critical outcomes, NEWS was superior to both SIRS (AUROC, 0.918 vs. 0.744, P = 0.032) and qSOFA (AUROC, 0.918 vs. 0.760, P = 0.012). Survival time was significantly shorter for patients with NEWS ≥ 7 than for patients with NEWS < 7.

CONCLUSION

Calculation of the NEWS at the time of hospital admission can predict critical outcomes in patients with COVID-19. Early intervention for high-risk patients can thereby improve clinical outcomes in COVID-19 patients.

Prognostic Factors for Severe Coronavirus Disease 2019 in Daegu, Korea

BACKGROUND

Since its first detection in December 2019, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 infection has spread rapidly around the world. Although there have been several studies investigating prognostic factors for severe COVID-19, there have been no such studies in Korea.

METHODS

We performed a retrospective observational study of 110 patients with confirmed COVID-19 hospitalized at a tertiary hospital in Daegu, Korea. Demographic, clinical, laboratory, and outcome data were collected and analyzed. Severe disease was defined as a composite outcome of acute respiratory distress syndrome, intensive care unit care, or death.

RESULTS

Diabetes mellitus (odds ratio [OR], 19.15; 95% confidence interval [CI], 1.90-193.42; P = 0.012), body temperature ≥ 37.8°C (OR, 10.91; 95% CI, 1.35-88.36; P = 0.025), peripheral oxygen saturation < 92% (OR, 33.31; 95% CI, 2.45-452.22; P = 0.008), and creatine kinase-MB (CK-MB) > 6.3 (OR, 56.84; 95% CI, 2.64-1,223.78, P = 0.010) at admission were associated with higher risk of severe COVID-19. The likelihood of development of severe COVID-19 increased with an increasing number of prognostic factors.

CONCLUSION

In conclusion, we found that diabetes mellitus, body temperature ≥ 37.8°C, peripheral oxygen saturation < 92%, and CK-MB > 6.3 are independent predictors of severe disease in hospitalized COVID-19 patients. Appropriate assessment of prognostic factors and close monitoring to provide the necessary interventions at the appropriate time in high-risk patients may reduce the case fatality rate of COVID-19.

The Risk of Diabetes on Clinical Outcomes in Patients with Coronavirus Disease 2019: A Retrospective Cohort Study

BACKGROUND

To determine the role of diabetes mellitus (DM) in the coronavirus disease 2019 (COVID-19), we explored the clinical characteristics of patients with DM and compared risk factors such as age, glycemic control, and medications to those without DM.

METHODS

This was a retrospective cohort study of 117 confirmed patients with COVID-19 which conducted at a tertiary hospital in Daegu, South Korea. The primary outcome was defined as the severe and critical outcome (SCO), of which the composite outcomes of acute respiratory distress syndrome, septic shock, intensive care unit care, and 28-day mortality. We analyzed what clinical features and glycemic control-related factors affect the prognosis of COVID-19 in the DM group.

RESULTS

After exclusion, 110 participants were finally included. DM patients (n=29) was older, and showed higher blood pressure compared to non-DM patients. DM group showed higher levels of inflammation-related biomarkers and severity score, and highly progressed to SCO. After adjustment with other risk factors, DM increased the risk of SCO (odds ratio [OR], 10.771; P<0.001). Among the DM patients, SCO was more prevalent in elderly patients of ≥70 years old and age was an independent risk factor for SCO in patients with DM (OR, 1.175; P=0.014), while glycemic control was not. The use of medication did not affect the SCO, but the renin-angiotensin system inhibitors showed protective effects against acute cardiac injury (OR, 0.048; P=0.045).

CONCLUSION

The COVID-19 patients with DM had higher severity and resulted in SCO. Intensive and aggressive monitoring of COVID-19 clinical outcomes in DM group, especially in elderly patients is warranted.

Analysis of SARS-CoV-2 Screening Clinic (Including Drive-Through System) Data at a Single University Hospital in South Korea from 27 January 2020 to 31 March 2020 during the COVID-19 Outbreak

In this study, we evaluated the efficiency of a drive-through (DT) screening system for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by comparing it with a conventional screening system. We reviewed and analyzed the SARS-CoV-2 screening data obtained at our university hospital. We compared the number of tests for SARS-CoV-2 (using real-time polymerase chain reaction) performed using two different specimen collection systems-DT and conventional-during the coronavirus disease 2019 (COVID-19) outbreak in Daegu. Based on the results, the DT screening system collected 5.8 times more specimens for testing than the conventional screening system. From January 27 to 31 March 2020, 6211 individuals were screened for SARS-CoV-2 infection using either the DT or conventional system. In total, 217 individuals tested positive for SARS-CoV-2 (positive rate: 3.50%). Of the 6211 individuals, 3368 were symptomatic or had a history of contact with COVID-19 patients, and 142 of them tested positive for SARS-CoV-2 (positive rate: 4.22%). Further, 2843 individuals were asymptomatic and had no history of contact with COVID-19 patients, and 75 of them tested positive for SARS-CoV-2 (positive rate: 2.64%). In conclusion, the DT system allowed clinicians to collect specimens for SARS-CoV-2 screening more efficiently than the conventional system. Furthermore, as there might be several COVID-19 patients who remain asymptomatic, expanding the screening test to asymptomatic individuals would be necessary.

Antimicrobial Susceptibility of Microorganisms Isolated from Patients with Intraabdominal Infection in Korea: a Multicenter Study

BACKGROUND

This study evaluated the antimicrobial susceptibility of pathogens isolated from Korean patients with intraabdominal infections (IAIs).

METHODS

This multicenter study was conducted at 6 university-affiliated hospitals in Korea between 2016 and 2018. All patients with microbiologically proven IAIs were retrospectively included, while patients with spontaneous bacterial peritonitis or continuous ambulatory peritoneal dialysis peritonitis were excluded. Identification and antimicrobial susceptibility testing were performed using automated microbiology systems.

RESULTS

A total of 2,114 non-duplicated clinical isolates were collected from 1,571 patients. Among these pathogens, 510 (24.1%) were isolated from nosocomial infections, and 848 isolates (40.1%) were associated with complicated IAIs. The distribution of the microorganisms included aerobic gram-negative (62.6% of isolates), aerobic gram-positive (33.7%), anaerobic (0.9%), and fungal (2.8%) pathogens. The most common pathogens were Escherichia coli (23.8%), followed by Enterococcus spp. (23.1%) and Klebsiella spp. (19.8%). The susceptibility rates of E. coli and Klebsiella spp. to major antibiotics were as follows: amoxicillin/clavulanate (62.5%, 83.0%), cefotaxime (61.4%, 80.7%), ceftazidime (63.7%, 83.1%), cefepime (65.3%, 84.3%), ciprofloxacin (56.4%, 86.3%), piperacillin/tazobactam (99.0%, 84.8%), amikacin (97.4%, 98.3%), and imipenem (99.8%, 98.8%). The susceptibility rates of Enterococcus spp. to ampicillin were 61.0%, amoxicillin/clavulanate, 63.6%; ciprofloxacin, 49.7%; imipenem, 65.2%; and vancomycin, 78.2%. The susceptibility rates of Pseudomonas aeruginosa and Acinetobacter spp. to imipenem were 77.4% and 36.7%, respectively.

CONCLUSION

Enterococcus spp. with susceptibility to limited antibiotics was one of the main pathogens in Korean IAIs, along with E. coli and Klebsiella spp., which were highly susceptible to imipenem, amikacin, and piperacillin/tazobactam. Meanwhile, the low susceptibilities of E. coli or Klebsiella spp. to amoxicillin/clavulanate, advanced-generation cephalosporins, and ciprofloxacin should be considered when determining empirical antibiotic therapy in clinical practice.

Clinical implications of multidrug-resistant microorganisms and fungi isolated from patients with intra-abdominal infections in the Republic of Korea: a multicenter study

The purpose of this study was to evaluate the clinical significance of fungi and multidrug-resistant organisms (MDROs) isolated from patients with intra-abdominal infections (IAIs). This multicenter study included consecutive patients admitted for microbiologically proven IAIs at 6 university-affiliated hospitals in South Korea between 2016 and 2018. A total of 1571 patients were enrolled. Multivariable logistic regression analysis revealed that the isolation of MDROs, isolation of Candida spp., underlying renal diseases, Charlson comorbidity score ≥ 3, septic shock, failure to receive a required surgery or invasive intervention, secondary bacteremia due to IAIs, and lower body mass index were found to be independent predictors for 28-day mortality. However, the isolation of Enterococcus spp. was not identified as a significant risk factor. MDROs and Candida spp. were found in 42 (2.7%) and 395 (25.1%), patients respectively. The isolation of MDROs or Candida spp. was a surrogate marker of 28-day mortality.

2186. Differentiation of Severe Fever with Thrombocytopenia Syndrome from Scrub Typhus

Background

SFTS and scrub typhus have similar clinical features and difficult to differentiate. Thus, a study to develop a scoring system to differentiate between two diseases in a clinical setting before the confirmation of laboratory results was reported by Kim et al. However, the statistical power could be low because of low numbers of cases (21 SFTS, 91 scrub typhus), our study analyzed by increasing the number of cases to overcome these limitations.

Methods

We retrospectively collected data from 183 SFTS and 178 scrub typhus patients who visited the 21 hospitals in South Korea between October, 2013 and November, 2017. The study protocol was approved by the IRB of each institution. SFTS was diagnosed through detection of SFTS viral RNA using RT–PCR. Scrub typhus was diagnosed either detection of 56-kDa antigen of O. tsutsugamushi using nested PCR or ≥ 4 fold rise in IgM or IgG titer using indirect IFA. Statistical analyses were performed by using SPSS and Medcalc.

Results

To differentiate SFTS from scrub typhus, we applied the scoring system proposed by Kim et al. After multivariable logistic regression, altered mental status, leukopenia, prolonged aPTT, and normal CRP(≤ 1.0 mg/dL) were significantly associated with SFTS compared with scrub typhus. Each variable was scored by 1 point, with a total score of 0–4 points, the optimal cutoff value was > 1 for the ROC curve. A score > 1 had 92% sensitivity, 96% specificity for diagnosis of SFTS, with a ROC AUC of 0.974. Because the sensitivity was less than 95%, we changed the normal CRP criteria to ≤ 3.0 mg/dL. The modified scoring system had 97% sensitivity, 96% specificity for diagnosis of SFTS, with an AUC of 0.983, and it showed a statistically higher accuracy than original scoring system (P = 0.0487). In this study, four factors for predicting SFTS were newly developed: leukopenia, prolonged aPTT, normal CRP (≤3.0 mg/dL), and elevated CK (>1,000 IU/L). Our study scoring system had 97% sensitivity, 98% specificity for diagnosis of SFTS, with an AUC of 0.992, and it showed a statistically higher accuracy than original scoring system (P = 0.0308).

Conclusion

In conclusion, we can easily differentiate SFTS from scrub typhus by using our scoring system of leukopenia, prolonged aPTT, normal CRP, and elevated CK in the endemic area.

Disclosures

All authors: No reported disclosures.

Toll-like receptors and inflammation in metabolic neuropathy; a role in early versus late disease?

Neuropathy is a common, morbid complication of the metabolic syndrome, prediabetes, and diabetes. Recent studies have indicated a potential role for the immune system in the development of neuropathy. In particular, toll-like receptors (TLR) 2 and 4 have been linked to metabolic dysfunction, and blocking TLR4 is proposed as a treatment for neuropathic pain. In the current study, we investigated the role of the immune system, particularly TLRs 2 and 4, in the pathogenesis and progression of neuropathy. Sural or sciatic nerve gene expression arrays from humans and murine neuropathy models of prediabetes and diabetes were first analyzed to identify differentially expressed TLR2- and TLR4-associated genes within the KEGG (Kyoto Encyclopedia of Genes and Genomes) database. We observed that genes associated with TLRs 2 and 4, particularly lipopolysaccharide binding protein (LPB) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta (PIK3CB), were dysregulated across species and across multiple murine models of prediabetic and diabetic neuropathy. To further understand the role of these pathways in vivo, TLR 2 and 4 global knockout mice placed on a 60% high fat diet (HFD-TLR2/4^-/-) were compared with wild type (WT) mice on a high fat diet (HFD-WT) and WT controls on a standard diet (CON). Mice then underwent metabolic, neuropathic, and immunological phenotyping at two time points to assess the impact of TLR signaling on neuropathy and immunity during metabolic dysfunction over time. We found that HFD-TLR2/4^-/- and HFD-WT mice weighed more than CON mice but did not have increased fasting blood glucose levels. Despite normal blood glucose levels, HFD-TLR2/4^-/- mice eventually developed neuropathy at the later time point (28 wks of age) but were somewhat protected from neuropathy at the early time point (16 wks of age) as measured by shorter hind paw withdraw latencies. This is in contrast to HFD-WT mice which developed neuropathy within 11 wks of being placed on a high fat diet and were neuropathic by all measures at both the early and late time points. Finally, we immunophenotyped all three mouse groups at the later time point and found differences in the number of peripheral blood Ly6C-myeloid cells as well as F4/80+ expression. These results indicate that TLR signaling influences early development of neuropathy in sensory neurons, potentially via immune modulation and recruitment.

Direct effectiveness of pneumococcal polysaccharide vaccine against invasive pneumococcal disease and non-bacteremic pneumococcal pneumonia in elderly population in the era of pneumococcal conjugate vaccine: A case-control study

BACKGROUND

While herd effects and serotype replacement by childhood pneumococcal protein conjugated vaccines (PCVs) continues to accumulate worldwide, direct effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPV23) against pneumococcal diseases in the elderly has been challenged. We estimated the direct effectiveness of PPV23 in the elderly population.

METHODS

For a hospital-based case-control study, cases of invasive pneumococcal disease (IPD) and non-bacteremic pneumococcal pneumonia (NBPP) (adults ≥ 65 years) were identified in 14 hospitals participated in the pneumococcal surveillance program from March 2013 to October 2015, following implementation of PPV23 national immunization program (NIP) for the elderly in the Republic of Korea. Controls matched by age, sex, and hospital were selected at ratios of 1:2 (IPD) or 1:1 (NBPP). Clinical data and vaccination records were collected. Vaccine effectiveness was calculated as (1-adjusted odds ratio) × 100.

RESULTS

We enrolled 148 IPD and 557 NBPP cases, and 295 IPD and 557 NBPP controls for analyses. Overall effectiveness of PPV23 against IPD was 28.5% [95% confidence interval (CI) -5.8%-51.6%] and against NBPP was 10.2% (-15.1-30.6) in all patients ≥ 65 years. However, in subgroup analysis of patients aged 65-74 years, PPV23 was protective against IPD [effectiveness 57.4% (19.4-77.5)] and against NBPP [effectiveness 35.0% (2.3-56.7)]. Furthermore, serotype-specific effectiveness of PPV23 against IPD was 90.6% (27.6-98.8) for PPV23-unique serotypes and 81.3% (38.6-94.3) for PPV23 serotypes excluding serotype 3.

CONCLUSIONS

This study indicates that PPV23 with broad serotype coverage might be beneficial in preventing IPD and NBPP due to non-PCV13 serotypes in the young-elderly, with potentially increasing effectiveness in the setting of childhood PCV NIP.

Severe fever with thrombocytopenia syndrome: comparison with scrub typhus and clinical diagnostic prediction

Background

Severe fever with thrombocytopenia syndrome (SFTS) is emerging in Asian 3 countries, China, Japan and Korea, which are scrub typhus endemic areas, and its incidence is increasing. As the two infections overlap epidemiologically and clinically and the accessibility or sensitivity of diagnostic tests is limited, early clinical prediction may be useful for diagnostic and therapeutic purposes.

Methods

Patients aged ≥16 years who were clinically suspected and laboratory-confirmed to be infected with Orientia tsutsugamushi or the SFTS virus in South Korea were enrolled. Clinical and laboratory parameters were compared. Scrub typhus was further subclassified according to the status of eschar and skin rash. An SFTS prediction scoring tool was generated based on a logistic regression analysis of SFTS compared with scrub typhus.

Results

The analysis was performed on 255 patients with scrub typhus and 107 patients with SFTS. At initial presentation, subjective symptoms except for gastrointestinal symptoms, were more prominent in scrub typhus patients. In addition to the characteristic eschar and skin rash, headache was significantly more prominent in scrub typhus, while laboratory abnormalities were more prominent in SFTS. Leukopenia (white blood cell count < 4000/mm³; odds ratio [OR] 30.13), thrombocytopenia (platelet count < 80,000 /mm³; OR 19.73) and low C-reactive protein (< 1 mg/dL; OR 67.46) were consistent risk factors for SFTS (all P < 0.001). A prediction score was generated using these 3 variables, and a score ≥ 2 had a sensitivity of 93.1% (95% confidence interval [CI], 87.9–96.4%) and a specificity of 96.1% (95% CI, 93.8–97.6%) for SFTS.

Conclusion

This prediction scoring tool may be useful for differentiating SFTS from eschar- or skin rash-negative scrub typhus. It is a simple and readily applicable tool with potential for use in primary care settings.

Abstract P4-06-23: Feasibility of sygeneic mice models of breast cancer for research of immune checkpoint blockades

Background: With the increasing success of immune checkpoint blockades for cancer treatment, we increasingly need well-characterized preclinical models. Syngeneic mice models (with a fully competent immune system) have advantages that they are easily established and cost less, though they do not reflect genetic complexity of human tumors. We evaluated feasibility of syngeneic mice models of breast cancer by analyzing efficacy of immune checkpoint blockade and dynamic change of tumor immune microenvironment.

Methods: We used syngeneic mice model of JC, 4T1, and EMT6 cells, which are all murine triple negative breast cancer in BALB/c mice. At the time when subcutaneous tumors reach at 50˜100mm^3, each mice models were divided into 2 groups for treatment versus no-treatment control. In the treatment group, mice version of anti-PD-1 antibody was intraperitoneally injected (q 3 days, x 6). Anti-tumor efficacy was monitored by measuring tumor volume. 'Tumor response' was defined as a case with tumor volume less than that of control group by a standard error at a determined time point. Immune microenvironment was evaluated by measuring serum cytokines (IL-2, IL-6, IL-10, IFNγ, and TNFα) with legendplex and immune cells (CD3, CD4, CD8, CD56, and FOXP3) of peripheral blood with FACS before injection of PD-1 blockade, after 1st injection, and when euthanized. Tumor-infiltrating immune cells were evaluated with FACS, when euthanized.

Results: The tumor response rate to PD-1 blockade was highest in the 4T1 model (54.5%, 6/11) compared to JC model (40%, 4/10) or EMT6 model (36.4%, 4/11). Bleeding 3 times and tumor obtainment when euthanized in each mouse were feasible for profiling of cytokines and immune cells. Although before treatment with PD-1 blockade, CD3+T cells in peripheral blood were slightly lower in 4T1 model (18.3±8.1%) than JC model (24.6±4.7%) or EMT6 model (27.9±6.3%), after injection of one dose of PD-1 blockade, CD3+T cells increased 1.5 times in 4T1 model (18.3% to 27.3%), whereas those CD3+T cells decreased slightly in JC model and EMT6 model. Dynamic changes were not observed in other subsets of peripheral immune cells in all 3 models. Serum TNFα (with statistical significance) and IFNγ (with borderline significance) were higher in responders than in non-responders or no-treatment control.

Conclusions: Syngeneic mice models of breast cancer were feasible to investigate immune checkpoint blockades and monitor dynamic change of immune microenvironment. In this regard, such models may be used to evaluate immune checkpoint blockade-based combination therapy as well.

Citation Format: Moon YW, Park N, Hur J, Pandey K, Cho YB, Kim SK, Lee SA, Son GW, Jo JM, An H-J. Feasibility of sygeneic mice models of breast cancer for research of immune checkpoint blockades [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-06-23.

Preliminary Report of Seroprevalence of Anti-Measles Immunoglobulin G among Healthcare Workers of 6 Teaching Hospitals of Daegu, Korea in 2019

The measles outbreak in Daegu of January 2019 made 6 teaching hospitals' organization test the measles immunity of their healthcare workers (HCWs). We found that 6,935 (75.9%) of 9,132 HCWs tested seropositive for anti-measles immunoglobulin G (IgG), and seropositivity rate was very different between 6 hospitals (range, 59.9–93.1%). The seroprevelence was lowest in the age of twenties, but the rate was different between 6 hospitals (range 47.0–85.5%). Therefore, to prevent measles from spreading to HCWs, each hospital should make their own data periodically about anti-measles IgG seropositivity of their HCWs.

Adult invasive pneumococcal disease in the Republic of Korea: Risk medical conditions and mortality stratified by age group

OBJECTIVES

This study aimed to characterize the risk factors for mortality in adult patients with invasive pneumococcal disease (IPD) stratified by age groups, after implementation of the national immunization program of 23-valent polysaccharide vaccine (PPSV23) for those aged ≥65 years in the Republic of Korea (ROK).

METHODS

Clinical data and pneumococcal isolates from adult patients with IPD (≥18 years of age) were collected prospectively from 20 hospitals through the nationwide surveillance program from March 2013 to October 2015.

RESULTS

A total of 319 patients with IPD were enrolled. Median age was 69 years. Overall in-hospital mortality was 34.2%: 17.1% in those aged 18-49 years, 23.7% in those aged 50-64 years, 33.0% in those aged 65-74 years, and 51.0% in those aged ≥75 years (p<0.001). In particular, early death within 7days of hospitalization accounted for 60.6% (66/109). While old age (≥65 years), higher Pitt bacteremia score (≥4), and bacteremic pneumonia were independently associated with IPD mortality in all age groups, an additional mortality risk factor of immunocompromised status was identified for patients aged 50-64 years. PPSV23 serotypes accounted for 64.4% (122/189) of the pneumococcal isolates serotyped.

CONCLUSIONS

This study suggests that vaccine-type IPD continues to place a substantial burden on older adults in the ROK, necessitating an effective vaccination strategy for those at higher risk.

Abnormal RNA stability in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) share key features, including accumulation of the RNA-binding protein TDP-43. TDP-43 regulates RNA homeostasis, but it remains unclear whether RNA stability is affected in these disorders. We use Bru-seq and BruChase-seq to assess genome-wide RNA stability in ALS patient-derived cells, demonstrating profound destabilization of ribosomal and mitochondrial transcripts. This pattern is recapitulated by TDP-43 overexpression, suggesting a primary role for TDP-43 in RNA destabilization, and in postmortem samples from ALS and FTD patients. Proteomics and functional studies illustrate corresponding reductions in mitochondrial components and compensatory increases in protein synthesis. Collectively, these observations suggest that TDP-43 deposition leads to targeted RNA instability in ALS and FTD, and may ultimately cause cell death by disrupting energy production and protein synthesis pathways.

Administration of Cripto in GRP78 overexpressed human MSCs enhances stem cell viability and angiogenesis during human MSC transplantation therapy

OBJECTIVES

The purpose of this study was to explore the effectiveness of concurrent GRP78 overexpression combined with Cripto on hMSC proliferation and migration both in vitro and in vivo. Specifically, we explored whether the treatment enhances effectiveness of hMSC transplantation in ischaemic tissue.

MATERIALS AND METHODS

Human MSCs obtained from human adipose tissue were cultured in α-minimum essential medium (Hyclone, Logan, UT, USA) supplemented with 10% (v/v) foetal bovine serum (Hyclone), 100 U mL^-1 penicillin and 100 μg mL^-1 streptomycin. Murine hindlimb ischaemic model was generated with 8-week-old male nude BALB/c mice (Biogenomics, Seoul, Korea) maintained under a 12-h light/dark cycle following the established protocol with minor modification. Cellular injection was performed no later than 3 hour after surgery. Lipofectamine transfection, single-cell cultivation assay, transwell assay, scratch wound-healing migration assay, immunohistochemistry and western blotting assays were performed.

RESULTS

Overexpression of GRP78 along with Cripto enhanced hMSC proliferation, migration and invasion. It increased interaction of surface GRP78 receptor with Cripto via JAK2/STAT3 pathway. We confirmed our proposed mechanism by showing that treatment with GRP78 antibody blocks the enhancement in vitro. In vivo, we observed that Cripto induced by the hypoxic environment in hindlimb ischaemic model interacts with the overexpressed GRP78 and increases hMSC proliferation, migration and invasion potentials as well as angiogenesis around transplanted ischaemic site via cytokine secretions.

CONCLUSIONS

These results demonstrate supporting evidences that GRP78-Cripto combination technique offers novel strategy to enhance MSC proliferation, migration and invasion potentials as well as angiogenesis around ischaemic site, ultimately facilitating MSC-based transplantation therapy in ischaemic conditions.

Medication nonadherence in Korean patients with rheumatoid arthritis: the importance of belief about medication and illness perception

BACKGROUND/AIMS

To investigate medication nonadherence in Korean patients with rheumatoid arthritis (RA) and analyze related factors.

METHODS

A total of 292 patients with RA participated in this study. Medication nonadherence, intentional or unintentional, was gauged via self-reported questionnaire. Patient perceptions of illness, treatment beliefs, and moods were measured via Brief Illness Perception Questionnaire, Beliefs about Medicines Questionnaire, and Patient Health Questionnaire-2, respectively. Demographic and clinical data were also collected. Multinomial regression analysis was used to assess the impact of demographic, clinical, and psychological factors on medication nonadherence.

RESULTS

The medication nonadherence rate was 54.1% (intentional, 21.6%; unintentional, 32.5%). Intentional nonadherence was reported most often in patients treated daily drugs (nonsteroidal anti-inflammatory drugs and/or disease-modifying antirheumatic drugs) (24.2%), and unintentional nonadherence was highest in patients receiving methotrexate (33.3%) (p = 0.872). In univariate analysis, beliefs in necessity and concerns of medication differed significantly in adherent and nonadherent patients (intentional or unintentional). When controlling for other factors that may impact medication nonadherence, less belief in necessity of medication (odds ratio [OR], 0.81; 95% confidence interval [CI], 0.68 to 0.95) and greater emotional response to disease (OR, 1.19; 95% CI, 1.01 to 1.40) were important predictors of intentional nonadherence.

CONCLUSIONS

Medication nonadherence is common in Korean patients with RA. Less belief in necessity of medication and greater emotional response to disease were identified as key factors prompting intentional nonadherence. These factors may be strategically targeted to improve medication adherence rates and subsequent clinical outcomes.

Effect of Early Plasma Exchange on Survival in Patients with Severe Fever with Thrombocytopenia Syndrome: A Multicenter Study

Despite a high mortality rate, no specific treatment for severe fever with thrombocytopenia syndrome (SFTS) has been established. This study compared the clinical outcomes of SFTS patients treated with plasma exchange (PE group) with those who were not treated (non-PE group) at nine Korean hospitals between May 2013 and August 2015. A total of 53 SFTS patients were included: 24 (45.3%) PE cases and 29 (54.7%) non-PE cases. The overall in-hospital mortality rate was 32.1% (17/53). The in-hospital mortality rate of the PE group did not differ from that of the non-PE group (29.3% vs. 34.5%, p=0.680). Of the 24 PE cases, 16 (66.7%) were treated with PE within 7 days of symptom onset (early PE group). The early PE group survived longer than the non-PE group (mean 28.4 days vs. 22.6 days, p=0.044). Multivariate analysis showed an inverse association between early PE implementation and 30-day mortality (adjusted hazard ratio 0.052, 95% confidence interval 0.004-0.678, p=0.024). The results of this study suggest that early PE implementation may have a beneficial effect on the clinical outcome of SFTS patients.

Severe Fever with Thrombocytopenia Syndrome in South Korea, 2013-2015

BACKGROUND

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that was recently identified in China, South Korea and Japan. The objective of the study was to evaluate the epidemiologic and clinical characteristics of SFTS in South Korea.

METHODS/PRINCIPAL FINDINGS

SFTS is a reportable disease in South Korea. We included all SFTS cases reported to the Korea Centers for Disease Control and Prevention (KCDC) from January 2013 to December 2015. Clinical information was gathered by reviewing medical records, and epidemiologic characteristics were analyzed using both KCDC surveillance data and patient medical records. Risk factors for mortality in patients with SFTS were assessed. A total of 172 SFTS cases were reported during the study period. SFTS occurred throughout the country, except in urban areas. Hilly areas in the eastern and southeastern regions and Jeju island (incidence, 1.26 cases /105 person-years) were the main endemic areas. The yearly incidence increased from 36 cases in 2013 to 81 cases in 2015. Most cases occurred from May to October. The overall case fatality ratio was 32.6%. The clinical progression was similar to the 3 phases reported in China: fever, multi-organ dysfunction, and convalescence. Confusion, elevated C-reactive protein, and prolonged activated partial thromboplastin times were associated with mortality in patients with SFTS. Two outbreaks of nosocomial SFTS transmission were observed.

CONCLUSIONS

SFTS is an endemic disease in South Korea, with a nationwide distribution and a high case-fatality ratio. Confusion, elevated levels of C-reactive protein, and prolonged activated partial thromboplastin times were associated with mortality in patients with SFTS.

Comparison of Preferred Bite Sites Between Mites and Ticks on Humans in Korea

Identification of mite and tick bite sites provides important clinical information. The predominant mite species in Korea associated with scrub typhus are Leptotrombidium pallidum and Leptotrombidium scutellare The most abundant tick species is Haemaphysalis longicornis To date, there has been no comparative study on preferred bite sites between mites and ticks in humans. This study included a review of medical records and a field study. For mite bite sites, eschars were checked on 506 patients with scrub typhus, confirmed by indirect immunofluorescence assay or nested polymerase chain reaction on the 56-kDa type-specific antigen gene of Orientia tsutsugamushi Tick bite sites were identified and marked on a diagram for 91 patients who experienced tick bites within the previous year through a field epidemiological investigation. The mite and tick bite sites in Koreans were compared. The most frequently observed mite bite sites were the anterior chest, including the axillae (29.1%) and the abdominal region, including the inguinal area (26.1%). Tick bite sites were most frequent on the lower extremities (33.0%), followed by the abdominal region, including the inguinal area (26.4%), and upper extremities (26.4%). The distribution was significantly different between mite and tick bite sites (P < 0.001). There was a statistically significant difference in the mite bite (P = 0.001), but not tick bite sites (P = 0.985), between men and women. This is the first report on the differences between tick and mite bite sites, and may help clinicians reach a rapid diagnosis of mite- or tick-borne infection.

Population Pharmacokinetic Analysis of Piperacillin/Tazobactam in Korean Patients with Acute Infections

Background

For more effective and safer usage of antibiotics, the dosing strategy should be individualized based on the patients’ characteristics, including race. The aim of this study was to investigate the population pharmacokinetic (PK) profiles of piperacillin and tazobactam in Korean patients with acute infections.

Materials and Methods

At least four consecutive 2/0.25 g or 4/0.5 g doses of piperacillin/tazobactam (TZP) were intravenously infused over 1 h every 8 h for patients with creatinine clearance (CL_cr) ≤50 ml/min or CL_cr >50 mL/min, respectively. Blood samples from 33 patients at a steady-state were taken pre-dose and at 0 min, 30 min, and 4-6 h after the fourth infusion. The population PK analysis was conducted using a non-linear mixed-effects method. A likelihood ratio test was used to select significant covariates, with significance levels of P <0.05 for selection and P <0.01 for elimination.

Results

Both piperacillin PK and tazobactam PK were well described by a two-compartment model with first-order elimination. Creatinine clearance and body weight, as covariates on clearance (CL) and volume of central compartment (V1), were selected among the covariates possibly affecting PK parameters of both drugs. CL was defined as CL = 2.9 + 4.03 × CL_cr /47 for piperacillin and CL = 1.76 + 4.81 × CL_cr /47 for tazobactam. V1 was defined as V1 = 19.5 × weight/60 for piperacillin and V1 = 22.6 × weight/60 for tazobactam.

Conclusion

The PK profiles of TZP at a steady-state in Korean patients with acute infections were well described by a two-compartment model with first-order elimination. Both piperacillin and tazobactam clearances were significantly influenced by creatinine clearance.

The acceptable duration between occupational exposure to hepatitis B virus and hepatitis B immunoglobulin injection: Results from a Korean nationwide, multicenter study

BACKGROUND

Postexposure prophylaxis for occupational exposure to hepatitis B virus (HBV) plays an important role in the prevention of HBV infections in health care workers (HCWs). We examined data concerning the acceptable duration between occupational exposure and administration of a hepatitis B immunoglobulin (HBIG) injection in an occupational clinical setting.

METHODS

A retrospective analysis was conducted with data from 143 cases of HCWs exposed to HBV in 15 secondary and tertiary teaching hospitals between January 2005 and June 2013. Data were taken from the infection control records of each hospital.

RESULTS

Active vaccination after HBV exposure was started in 119 cases (83.2%) and postvaccination testing for hepatitis B antibody showed positive seroconversion in 93% of cases. In 98 cases (68.5%), HBIG was administered within 24 hours after HBV exposure; however, 45 HCWs (31.5%) received an HBIG injection more than 24 hours postexposure and 2 among the 45 received an injection after 7 days. Although 31.5% received an HBIG injection more than 24 hours postexposure, no cases of seroconversion to hepatitis b antibody positivity occurred.

CONCLUSIONS

For susceptible HCWs, HBIG administered between 24 hours and 7 days postexposure may be as effective as administration within 24 hours in preventing occupational HBV infection.

Dynamic 4D MRI for Characterization of Parathyroid Adenomas: Multiparametric Analysis

BACKGROUND AND PURPOSE

The hypervascular nature of parathyroid adenomas can be explored by proper dynamic imaging to narrow the target lesions for surgical exploration. The purpose of this study was to establish MR perfusion characteristics of parathyroid adenomas to differentiate them from their mimics, such as subjacent thyroid tissue and cervical lymph nodes.

MATERIALS AND METHODS

Preoperative high-spatial and -temporal resolution dynamic 4D contrast-enhanced MR imaging in 30 patients with surgically proved parathyroid adenomas was evaluated retrospectively. Using coregistered images, we placed ROIs over the parathyroid adenoma, thyroid gland, and a cervical lymph node (jugulodigastric) to obtain peak enhancement, time-to-peak, wash-in, and washout in each patient. Data were analyzed by logistic regression and analysis of variance. Receiver operating characteristic analysis was performed to determine the optimal parameters for determination of parathyroid adenomas versus thyroid tissue and cervical lymph nodes.

RESULTS

Parathyroid adenomas showed significantly (P < .05) faster time-to-peak, higher wash-in, and higher washout compared with cervical lymph nodes and significantly (P < .05) higher peak enhancement, faster time-to-peak, higher wash-in, and higher washout compared with thyroid tissue. Logistic regression analysis indicated significant contribution from time-to-peak (P = .02), wash-in (P = .03), and washout (P = .008) for differentiation of parathyroid adenomas from thyroid and cervical lymph nodes. Using receiver operating characteristic analysis, we obtained the best diagnostic accuracy from a combination of time-to-peak/wash-in/washout in the differentiation of parathyroid adenomas versus lymph nodes (area under the curve, 0.96; sensitivity/specificity, 88%/90%) and in distinguishing parathyroid adenomas versus thyroid tissue (area under the curve, 0.96; sensitivity/specificity, 91%/95%).

CONCLUSIONS

Dynamic 4D contrast-enhanced MR imaging can be used to exploit the hypervascular nature of parathyroid adenomas. Multiparametric MR perfusion can distinguish parathyroid adenomas from subjacent thyroid tissue or lymph nodes with diagnostic accuracies of 96%.

Sacral Herpes Zoster Associated with Voiding Dysfunction in a Young Patient with Scrub Typhus

When a patient presents with acute voiding dysfunction without a typical skin rash, it may be difficult to make a diagnosis of herpes zoster. Here, we present a case of scrub typhus in a 25-year-old man with the complication of urinary dysfunction. The patient complained of loss of urinary voiding sensation and constipation. After eight days, he had typical herpes zoster eruptions on the sacral dermatomes and hypalgesia of the S1-S5 dermatomes. No cases of dual infection with varicella zoster virus and Orientia tsutsugamushi were found in the literature. In the described case, scrub typhus probably induced sufficient stress to reactivate the varicella zoster virus. Early recognition of this problem is imperative for prompt and appropriate management, as misdiagnosis can lead to long-term urinary dysfunction. It is important that a diagnosis of herpes zoster be considered, especially in patients with sudden onset urinary retention.

Fever of Unknown Origin: An Unusual Presentation of Anti-N-Methyl-D-Aspartate Receptor Encephalitis

Encephalitis associated with antibodies to the N-methyl-D-aspartate receptor (NMDAR) has variable clinical manifestations. Patients are often diagnosed with infectious processes because of prodromal symptoms and autonomic manifestations. Approximately 70% of patients have prodromal symptoms consisting of headache, fever, nausea, vomiting, and diarrhea, along with frequent autonomic manifestations, including tachycardia, and fluctuating blood pressure. A 36-year-old woman presented with uncontrolled fever and skin and soft tissue infections. She had shown psychiatric symptoms and abnormal behavior, and had been diagnosed with bipolar disorder. Antibodies to NMDAR were positive in cerebrospinal fluid (CSF) and serum samples, and pelvic computed tomography detected a large ovarian teratoma. The patient improved dramatically after removal of the teratoma and administration of corticosteroid therapy. When confronted with a young woman with uncontrolled fever and acute psychiatric symptoms, physicians should suspect anti-NMDAR encephalitis.

Oral Antimicrobial Therapy: Efficacy and Safety for Methicillin-Resistant Staphylococcus aureus Infections and Its Impact on the Length of Hospital Stay

Background

Carefully switching from intravenous to oral antibiotic therapy has shown to reduce treatment costs and lengths of hospital stay as well as increase safety and comfort in patients with infections. The aim of this study was to compare the clinical efficacy and safety between the patients treated with glycopeptides (case group), and the patients given oral antibiotics, as the initial or step-down therapy (control group), in the treatment of patients with methicillin-resistant Staphylococcus aureus (MRSA) infection.

Materials and Methods

A multicenter observational study was retrospectively performed in 7 teaching hospitals in Korea from January to December 2012. The study included adult patients (≥ 18 years) with infection caused by MRSA isolates, susceptible to clindamycin, erythromycin, and ciprofloxacin. The primary end point was treatment outcome, including all-cause mortality and switching of antibiotics. Drug-related adverse events and the lengths of hospital stay were also compared between the two treatment groups.

Results

During the study period, 107 patients (43 cases and 64 controls) with MRSA infections were enrolled from the participating hospitals. The most common sites of MRSA infection were skin and soft tissue (n = 28) and bone and joint (n = 26). The median Charlson comorbidity index (P = 0. 560), the frequency of severe sepsis (P = 0.682) or thrombocytopenia (P = 1.000), and median level of serum C-reactive protein (P = 0.157) at the onset of MRSA infections were not significantly different between the case and control groups. The oral antibiotics most frequently prescribed in the case group, were fluoroquinolones (n = 29) and clindamycin (n = 8). The median duration of antibiotic treatment (P = 0.090) and the occurrence of drug-related adverse events (P = 0.460) did not reach statistically significant difference between the two groups, whereas the total length of hospital stay after the onset of MRSA infection was significantly shorter in the case group than the control group [median (interquartile range), 23 days (8-41) vs. 32 days (15-54), P = 0.017]. In multivariate analyses, the type of antibiotic used was not an independent risk factor for treatment failure. The statistically significant factors associated with treatment failure included underlying hepatic diseases, prior receipt of antibiotics, and foreign body retention.

Conclusions

This study indicates that oral antibiotic therapy with active agents against MRSA isolates can be considered as the initial or step-down therapy for the treatment of MRSA infections and also reduce the length of hospital stay.