Evaluation of humoral immune response after ChAdOx1 nCoV-19 vaccination among health care workers.

We assessed the immunogenicity of ChAdOx1 nCoV-19 vaccination by evaluating the levels of SARS-CoV-2 IgG after vaccination and investigated the effect of diverse factors such as gender, age, and adverse reactions after vaccination. The study included a total of 1028 serum samples from 452 healthcare workers. SARS-CoV-2 IgG levels were assessed using the SARS-CoV-2 IgG II Quant assay. Participants completed a questionnaire regarding the intensity and duration of adverse reactions after vaccination. The seropositive rates after the first and second doses were 95.5% and 100%, respectively. The median antibody levels after the second dose showed a 4.2-fold increase compared with the first. Five months after the second dose, the median antibody levels decreased by 3.5-fold. The antibody levels in men were lower than those in women after the first dose and were higher after the second dose. There was no difference according to age groups after the first dose, but after the second dose, in subjects aged 50 and above, the rise in antibody levels was less than that in other age groups. The antibody levels among participants with moderate or severe symptoms were significantly higher than those among participants with mild symptoms after the first dose. There were no statistically significant differences according to the duration of symptoms. We could assume that different age groups and genders might have different immunogenicity following vaccination. The intensity of adverse symptoms was positively correlated with the antibody levels, implying that higher immunogenicity is related to the intensity of adverse symptoms after vaccination.

Successful Treatment of Thrombotic Thrombocytopenic Purpura in a Patient with Mixed Connective Tissue Disease.

BACKGROUND: Although the survival rate of thrombocytopenic purpura (TTP) has increased significantly due to the introduction of therapeutic plasma exchange (TPE). TTP in patients with mixed connective tissue disease (MCTD) has a very high mortality rate and a very small number of reported cases. In TTP, daily TPE is administered until a treatment response is achieved; however, in practice, TPE is often not performed for such long durations. METHODS: We report a case of TTP with MCTD in a female patient. She had developed thrombocytopenia and hemolytic anemia 9 months after delivery. She had status epilepticus and lapsed into a coma. RESULTS: The patient was successfully treated with extended sessions of TPE with corticosteroids and rituximab. CONCLUSIONS: Although the TTP regimen has not yet been established and remains controversial, this report demonstrates the importance of continuing daily TPE until achieving a treatment response.

Verification and Establishment of Reference Intervals for Prothrombin Time and Activated Partial Thromboplastin Time for Children in a Clinical Laboratory.

BACKGROUND: Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are routine coagulation tests. The absence of age-dependent reference interval (RI) may lead to abnormal results in children. In this study, we aimed to verify adult-based RIs in children and establish pediatric RIs for PT and aPTT. METHODS: We analyzed PT and aPTT results. Samples from inpatients and outpatients aged 1 - 18 years, considered healthy subjects, were divided into six groups by age. Verification and establishment of RIs were conducted. RESULTS: Applying adult-based RIs to pediatrics was statistically invalid for individuals aged 10 - 18 years for PT and invalid throughout childhood for aPTT. The new RI of PT for individuals aged 10 - 18 years was 11.1 - 14.1 seconds and that of aPTT for individuals aged 1 - 9 years was 28.2 - 46.0 seconds. CONCLUSIONS: Pediatric RIs were higher than adult-based RIs. Using pediatric RI can save time, labor, and costs to make clinical decision.

Anti-LW Confused with Anti-D: a Case Transfused RhD-positive RBCs and Literature Review.

BACKGROUND: Anti-LW is rarely identified, and it is known to have little clinical importance. However, it is often difficult to differentiate anti-LW from anti-D. METHODS: Here, we report a case where anti-LW was identified for pretransfusion testing in a patient suspected of having lymphoma. RESULTS: His blood group was O RhD-positive. Anti-D specificity, weak panreactivity and 2+ reactivity in auto control were shown as a result of antibody identification. The reactions became weaker with DTT-treated RBCs, which confirmed the specificity of an anti-LW. The patient received 8 units of O RhD-positive pRBC before discharge without any transfusion reaction. CONCLUSIONS: In conclusion, anti-LWs may show mimicking specificity of anti-D for antibody identification testing, but their clinical significance is completely different. Therefore, their prompt identification is important.

Septic shock caused by Slackia exigua in a patient with diabetes.

We report a case of septic shock caused by Slackia exigua, an obligatory anaerobic gram-positive rod, in an 82-year-old woman with diabetes. Dental assessment revealed a palatal lesion and untreated periodontitis. Although a resident species in the oral cavity and associated with localized disorders, S. exigua can cause extra-oral diseases, which can be fatal in individuals with risk factors, such as diabetes. Thus, control of oral lesions caused by S. exigua is important to prevent systemic infection.

Need for Confirmatory Neutralization Tests for Hepatitis B Surface Antigen Tests in Populations with Intermediate Prevalence.

OBJECTIVE: Hepatitis B surface antigen (HBsAg) is known as the hallmark of hepatitis B virus (HBV) infection. This study aimed to determine whether an HBsAg neutralization test is necessary to accurately interpret HBsAg test results. METHODS: Initially reactive HBsAg specimens from a 5-year period, with cutoff index values between 1.0 and 2.0, were subjected to neutralization confirmatory testing using an Elecsys HBsAg Confirmatory test kit (Roche Diagnostics GmbH. Mannheim, Germany). RESULTS: The neutralization test showed 46.1% positive (confirmed positive group) and 53.9% negative (confirmed negative group) results from the total specimens. Among the confirmed negative group, 79.5% of patients were confirmed to be negative for the current infection, whereas 4 patients in the chronic hepatitis B subgroup showed a neutralization percentage close to 40%. More than half of patients in the confirmed positive group were considered to be in the hepatitis B e antigen-negative inactive HBsAg carrier phase. CONCLUSION: In populations with intermediate HBV prevalence, a neutralization test is necessary to confirm an HBsAg result and reduce the false positive and false negative rates of initial HBsAg tests.

Bacteremia Caused by Moraxella Osloensis: a Fatal Case of an Immunocompromised Patient and Literature Review.

BACKGROUND: Moraxella osloensis rarely causes infection in humans, and most of the reported cases are not fatal. It is often difficult to identify M. osloensis using conventional biochemical methods. METHODS: Here, we report a bacteremia case caused by M. osloensis in a patient with advanced lung cancer who initially presented symptoms of fever. RESULTS: Blood culture revealed growth of a gram-negative bacterium, which was identified as M. osloensis through 16S rRNA gene sequencing and MALDI-TOF analyses. The patient could not recover from sepsis with empirical treatment. CONCLUSIONS: As M. osloensis can cause serious infections in immunocompromised patients, its prompt identification is important.

Evaluation of HCV RNA by PCR and Signal-to-Cutoff Ratios of HCV Antibody Assays for Diagnosis of HCV Infection.

OBJECTIVE: In this study, we assessed whether a hepatitis C virus (HCV) RNA test could replace recombinant immunoblot assay (RIBA) and reduce unnecessary supplemental tests as the signal-to-cutoff (S/Co) ratio from anti-HCV antibody (Ab) tests. METHODS: Anti-HCV Ab tests were performed to screen for HCV infections, and RIBA and real-time polymerase chain reaction were performed for HCV RNA to confirm HCV infection. Receiver operating characteristic curves were evaluated to determine the optimal S/Co ratios for predicting HCV infection. RESULTS: The cutoff value for the S/Co ratio was 3.63 for predicting RIBA results and 10.6 for predicting HCV RNA results. Our data suggested that an S/Co ratio ≥10.6 indicated a high risk of active HCV infection. An S/Co ratio of 3.63 to 10.6 needed further evaluation and repeat HCV RNA testing. No further testing was required for S/Co ratios <3.63 or ≥10.6. CONCLUSION: We determined that the S/Co ratio of the anti-HCV Ab test provides useful information to confirm HCV infections, including the need for further laboratory testing or clinical follow-up.

Introduction of a Borderline Range for the Interpretation of QuantiFERON-TB Gold In-Tube Results in Korean Healthcare Workers.

BACKGROUND: South Korea is the only Organisation for Economic Co-operation and Development (OECD) country with a high incidence of tuberculosis (TB). Healthcare workers (HCWs) have an increased risk of TB infection. QuantiFERON-TB Gold In-Tube (QFT-GIT) testing is performed for occupational health screening to detect latent TB infection (LTBI). METHODS: We evaluated the introduction of new criteria for borderline ranges for interferon-gamma release assay (IGRA) results in HCWs. The results of QFT-GIT tests in HCWs in 2017 and 2018 were collected, with high-risk HCWs having two serial test results. Existing dichotomous criteria and new criteria with borderline ranges (bor-derline negative [BN], 0.20 - 0.34 IU/mL; borderline positive [BP], 0.35 - 0.99 IU/mL) were applied to each test re-sult. RESULTS: After applying the borderline range, 26.4% of the positive results were classified as BP (4% of total results), while 4.2% of the negative results were classified as BN (3.6% of total results). Among seven HCWs with initial results in the borderline range, two had repeated borderline results while 71.4% had low negative results. CONCLUSIONS: We recommend the introduction of borderline ranges in the interpretation of QFT-GIT results to reduce unnecessary TB therapy in HCWs.

Etest Methods for Screening Heterogeneous Vancomycin-Intermediate Staphylococcus aureus (hVISA) strains.

The importance of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) as a preceding stage for the development of vancomycin-resistant S. aureus is growing. We analyzed the prevalence of hVISA among bacteremia with methicillin-resistant S. aureus (MRSA) using two Etests and evaluated the clinical characteristics and outcomes. Ninety-eight MRSA isolates from blood were collected at two University hospitals in Korea. Macrodilution Etest and glycopeptide resistance detection Etests were used for detection of hVISA. Staphylococcal cassette chromosome mec (SCCmec) typing was performed by multiplex PCR. Clinical data were collected retrospectively from patient medical records. About 30% of MRSA strains were identified as hVISA. Diabetes mellitus was associated (P = 0.047) with hVISA infections. The hVISA isolates were associated with high teicoplanin MIC and multidrug resistance (P = 0.001). SCCmec type II accounted for the majority (79.3%) of hVISA strains. The prevalence of hVISA strains was increased and can lead to the development of multidrug-resistant strains. Patients with diabetes were found to have a greater risk for infection with hVISA strains. As the impact of hVISA on clinical outcome is not yet clear, large-scale studies about clinical outcomes and optimal detection methods of hVISA are needed. In conclusion, hVISA strains have a high prevalence in bloodstream MRSA infections. Awareness of the increase in hVISA strains should motivate laboratories to establish a system to detect and monitor hVISA.

Clinical Aspects of the Dense Fine Speckled Pattern in Indirect Immunofluorescence-Antinuclear Antibody Screening and Its Association with DFS70 Autoantibodies.

GOALS: The existence of anti-dense fine speckled (DFS) 70 autoantibodies are considered an exclusionary biomarker for systemic autoimmune rheumatic diseases (SARDs). Several tests to confirm the presence of anti-DFS70 autoantibodies have been introduced, and the use of them in specimens with a DFS pattern in indirect immunofluorescence-antinuclear antibody (IIF-ANA) testing has been suggested. However, these additional tests have only been evaluated in a small number of samples; their clinical usefulness therefore requires further evaluation. METHODS: A total of 213 serum specimens showing DFS (n=155) or homogeneous (H; n=58) patterns were included. All specimens were tested by western blotting (WB) and enzyme immunoassay (EIA). Clinical information regarding SARDs was analyzed. RESULTS: The detection rates for WB and EIA for anti-DFS70 autoantibodies in specimens with a DFS pattern were 86.5% and 73.5%, respectively. Detection rates in specimens with a low IIF-ANA titer were significantly lower than those in specimens with a high titer. The detection rate of anti-DFS70 autoantibodies in 58 specimens with an H pattern was 10.3% (6/58). Among 155 subjects with a DFS pattern in IIF-ANA staining, only five were diagnosed with SARD. CONCLUSIONS: There is little need to confirm the presence of anti-DFS70 autoantibodies using other methods. When a DFS pattern is observed in IIF-ANA staining, it is more important to confirm the presence of other autoantibodies related to SARDs than to identify anti-DFS70 autoantibodies. Finally, more careful interpretation of IIF-ANA to specimens with a low IIF-ANA titer is needed.

Device-Related Error in Patient-Controlled Analgesia: Analysis of 82,698 Patients in a Tertiary Hospital.

BACKGROUND: Patient-controlled analgesia (PCA) is one of the most popular and effective methods for managing postoperative pain. Various types of continuous infusion pumps are available for the safe and accurate administration of analgesic drugs. Here we report the causes and clinical outcomes of device-related errors in PCA. METHODS: Clinical records from January 1, 2011 to December 31, 2014 were collected by acute pain service team nurses in a 2715-bed tertiary hospital. Devices for all types of PCA, including intravenous PCA, epidural PCA, and nerve block PCA, were included for analysis. The following 4 types of infusion pumps were used during the study period: elastomeric balloon infusers, carbon dioxide-driven infusers, semielectronic disposable pumps, and electronic programmable pumps. We categorized PCA device-related errors based on the error mechanism and clinical features. RESULTS: Among 82,698 surgical patients using PCA, 610 cases (0.74%) were reported as human error, and 155 cases (0.19%) of device-related errors were noted during the 4-year study period. The most common type of device-related error was underflow, which was observed in 47 cases (30.3%). The electronic programmable pump exhibited the high incidence of errors in PCA (70 of 15,052 patients; 0.47%; 95% confidence interval, 0.36-0.59) among the 4 types of devices, and 96 of 152 (63%) patients experienced some type of adverse outcome, ranging from minor symptoms to respiratory arrest. CONCLUSIONS: The incidence of PCA device-related errors was <0.2% and significantly differed according to the infusion pump type. A total of 63% of patients with PCA device-related errors suffered from adverse clinical outcomes, with no mortality. Recent technological advances may contribute to reducing the incidence and severity of PCA errors. Nonetheless, the results of this study can be used to improve patient safety and ensure quality care.

Clinical use of anti-DFS70 autoantibodies.

The dense fine speckled (DFS) nuclear pattern is one of the most common indirect immunofluorescence (IIF) patterns detected during routine anti-nuclear antibody (ANA) screening. There is a negative association between anti-DFS70 status and systemic autoimmune rheumatic disease (SARD), especially in the absence of concomitant SARD-specific autoantibodies. The purpose of this study was to determine the need for confirming anti-DFS70 status when a DFS pattern is observed in IIF-ANA. The frequency of anti-DFS70 detection on Western blot and the positive rate of connective tissue disease (CTD)-related autoantibody screening with a fluorescence-based enzyme immunoassay was evaluated in DFS (n = 182) and non-DFS (n = 359) groups. Specific autoantibodies against 15 autoantigens were identified by line immunoassay. We evaluated the frequency of cases of DFS mistaken for non-DFS and non-DFS cases mistaken for DFS, as well as the clinical impacts of these misinterpretations. Among cases of IIF-ANA with an observable DFS pattern, 68.1% had only anti-DFS70 without CTD-related autoantibodies, 20.3% were false positive for IIF-ANA, and the remaining 11.5% had CTD-related autoantibodies independent of anti-DFS70 status. These results indicated that CTD-related autoantibodies may be present with or without anti-DFS70 even if a DFS pattern is observed in IIF-ANA. Among patients who are ANA negative or have a low probability of SARD, an anti-DFS70 confirmation test has no clinical benefit and cannot replace specific tests for detecting CTD-related autoantibodies. Specific tests to detect CTD-related autoantibodies should be performed instead of anti-DFS70 confirmation tests when a DFS pattern is observed in IIF-ANA.

Neutrophil-to-Monocyte-Plus-Lymphocyte Ratio as a Potential Marker for Discriminating Pulmonary Tuberculosis from Nontuberculosis Infectious Lung Diseases.

OBJECTIVE: To determine whether NMLR has more statistical strength than NLR in discriminating TB from non-TB infectious lung diseases. METHODS: Among patients who underwent 3 or more TB culture tests with molecular study between January 2016 and December 2017, 110 patients with TB, and 159 patients diagnosed with non-TB infectious lung diseases were enrolled. The original complete blood count (CBC) parameters and modified CBC indices, including NLR and NMLR, were analyzed. RESULTS: The NLR and NMLR were significantly lower in TB patients than in patients with other infectious lung diseases. However, the area under the curve (AUC) for NMLR (0.90; 95% confidence interval [CI], 0.86-0.93) was significantly greater than that for NLR (0.88 [0.84-0.92]). CONCLUSIONS: The neutrophil-to-monocyte-plus-lymphocyte ratio (NMLR) can be used as a new index that is more powerful than neutrophil-to-lymphocyte ratio (NLR) in discriminating tuberculosis (TB) from non-TB infectious lung diseases.NMLR had more statistical strength than NLR in discriminating TB from non-TB infectious lung diseases.

Bell Palsy and the Risk of Cardio-Cerebrovascular Disease: A Population-Based Follow-Up Study.

OBJECTIVE: To evaluate the risk of cardio-cerebrovascular disease (CCVD), such as ischemic stroke and acute myocardial infarction (AMI), in patients diagnosed with Bell palsy STUDY DESIGN: Population-based follow-up study. METHODS: We used the National Sample Cohort 2002 to 2013 data from the Korea National Health Insurance Service. The Bell palsy group comprised all patients diagnosed with Bell palsy (n = 730). The comparison group comprised patients selected randomly using propensity score matching (n = 1,460). The Kaplan-Meier survival analysis, log-rank test, and Cox proportional-hazards regression models were used to calculate the disease-free survival rate and hazard ratio (HR) of CCVD for each group. RESULTS: Of the total study population, ischemic stroke developed in 15.7% of patients with Bell palsy and 9% of patients in the comparison group during the 12-year follow-up period. After adjusting for other factors, the HR of ischemic stroke during the 12-year follow-up period was 1.84 times greater in the Bell palsy group than in the comparison group (95% confidence interval [CI], 1.43-2.36). However, the adjusted HR of developing ischemic stroke for patients with Bell palsy treated concurrently with antiviral agents and steroids was 1.12 (95% CI, 0.62.-2.04). There was no significant relationship between Bell palsy and risk of AMI development (HR, 1.13; 95% CI, 0.71-1.82). CONCLUSION: Bell palsy is linked with an increased incidence of ischemic stroke. Our data suggest that Bell palsy may be used as an indicator of increased stroke risk, and concurrent treatment with antiviral agents and steroids may be effective in preventing ischemic stroke. LEVEL OF EVIDENCE: NA Laryngoscope, 129:2371-2377, 2019.

Clinical Characteristics and Management of Saccular Cysts: A Single Institute Experience.

OBJECTIVES: A saccular cyst is defined as a dilated saccule of the larynx, filled with mucus, and is located between the false vocal cords and the thyroid cartilage. Although this uncommon laryngeal condition is benign in nature, it could lead to dyspnea, stridor, and airway obstruction, depending on its size and location. Furthermore, some saccular cysts have been associated with laryngeal carcinoma. This study aimed to characterize this rather uncommon laryngeal condition to aid in determining the proper management of this pathology. METHODS: Medical records were retrospectively reviewed of all patients with saccular cysts diagnosed and treated between 2006 and 2017 at a tertiary otolaryngologic care center. RESULTS: Seven patients with saccular cysts were identified (male:female=2:5; mean age, 34.1 years); two were pediatric patients. Surgical intervention was performed in all patients by laryngo-microsurgery using CO2 laser. There was no recurrence after the initial surgical treatment. CONCLUSION: Saccular cysts can be managed endoscopically using CO2 laser, without requiring an external approach. Therefore, an endoscopic approach should be actively considered for an optimal treatment outcome.

Misidentification of Acinetobacter baumannii as Alcaligenes faecalis by VITEK 2 System; Case Report.

Acinetobacter baumannii (A. baumannii) is widely known as an opportunistic bacterial pathogen that causes infection more frequently among immunocompromised individuals. Our case demonstrated the limitation of the current VITEK 2 system for the idendification of A. baumannii. Four clinical isolates of A. baumannii were identified as Alcaligenes faecalis by the VITEK 2 system. Misidentification might lead to unnecessary tests and inappropriate treatments. Additional methods appear to be helpful for the accurate identification of A. baumannii for clinical microbiology laboratories.

Urinary exosomal viral microRNA as a marker of BK virus nephropathy in kidney transplant recipients.

OBJECTIVE: Bkv-miR-B1-5p, one of the microRNAs encoded by BK virus, was recently reported to be elevated in the blood among the patients with BK virus nephropathy (BKVN). Urinary exosome was suggested to be a possible source of biomarker for kidney diseases, but it was unknown whether it could contain viral microRNA as well as human microRNAs. The aim of this study was to evaluate whether urinary exosomal BK viral microRNA were expressed during replication and could be used to diagnose BKVN in kidney transplant recipients. MATERIALS AND METHODS: In a cross-sectional multicenter study, we collected and analyzed 458 graft biopsies from 385 kidney transplant recipients. Urine samples were collected at the time of graft biopsy, and microRNAs in urinary exosome were measured once. For 13 patients with BKVN and 67 age, sex-matched kidney transplant recipients, we measured BK viral microRNA B1-5p, 3p and human microRNA-16 in urinary exosomal fraction and compared the diagnostic value with BK viral load in plasma and urine. RESULTS: Pathology proven BKVN was diagnosed in 13 patients (2.8%). High levels of bkv-miR-B1-5p and bkv-miR-B1-3p were shown in all patients with BKVN. Meanwhile, plasma BK viral load assay (cut-off value of ≥ 4.0 log10 copies/mL) showed false negative in 3 cases and urinary BK viral load assay (cut-off value of ≥ 7.0 log10 copies/mL) showed false negative in 1 case among these 13 patients. The receiver operator characteristics curve analysis for bkv-miR-B1-5p and bkv-miR-B1-5p/miR-16 showed excellent discriminative power for the diagnosis of BKVN, with area under the curve values of 0.989 and 0.985, respectively. CONCLUSIONS: This study suggests that urinary exosomal bkv-miR-B1-5p and bkv-miR-B1-5p/miR-16 could be surrogate markers for the diagnosis of BKVN.

Modified Complete Blood Count Indices as Predicting Markers of Preeclampsia from Gestational Hypertension: Neutrophil to Lymphocyte Ratio, Platelet to Lymphocyte Ratio, and Platelet to Neutrophil Ratio.

BACKGROUND: To evaluate modified complete blood count (CBC) indices as a predicting marker of preeclampsia (PE) from gestational hypertension (GH), we analyzed the neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and platelet to neutrophil ratio (PNR). PNR was a newly designed index in this study based on results of PE patients having a tendency toward higher neutrophil count and lower platelet count compared to normal pregnant women in previous studies. METHODS: We recruited 86 normal pregnant women, 33 patients with GH and 68 patients with PE. Subjects with any history of membrane rupture, infection, or multiple pregnancies were excluded. PNR, NLR, and PLR values including other CBC indices were statistically analyzed. RESULTS: NLR value of PE patients was significantly higher than GH patients (p = 0.011). PNR value was the most statistically significant index separating patients with PE and GH (p < 0.001). PLR value was lower in patients with PE compared to GH; however, statistical significance was low. CONCLUSIONS: NLR as well as PNR is a useful index to help predicting progression from GH to PE. Further studies are required to evaluate the full extent of utility of PNR as a predictive index in PE patients.