Neurotrophic factor Neuritin modulates T cell electrical and metabolic state for the balance of tolerance and immunity

The adaptive T cell response is accompanied by continuous rewiring of the T cell's electric and metabolic state. Ion channels and nutrient transporters integrate bioelectric and biochemical signals from the environment, setting cellular electric and metabolic states. Divergent electric and metabolic states contribute to T cell immunity or tolerance. Here, we report that neuritin (Nrn1) contributes to tolerance development by modulating regulatory and effector T cell function. Nrn1 expression in regulatory T cells promotes its expansion and suppression function, while expression in the T effector cell dampens its inflammatory response. Nrn1 deficiency causes dysregulation of ion channel and nutrient transporter expression in Treg and effector T cells, resulting in divergent metabolic outcomes and impacting autoimmune disease progression and recovery. These findings identify a novel immune function of the neurotrophic factor Nrn1 in regulating the T cell metabolic state in a cell context-dependent manner and modulating the outcome of an immune response.

Relatively preserved functional immune capacity with standard COVID-19 vaccine regimen in people living with HIV

Introduction

People living with HIV (PLWH) are at a higher risk of severe disease with SARS-CoV-2 virus infection. COVID-19 vaccines are effective in most PLWH. However, suboptimal immune responses to the standard two-shot regimen are a concern, especially for those with moderate to severe immunodeficiency. An additional dose is recommended as part of the extended primary series in Taiwan. Herein, we study the efficacy of this additional shot in PLWH with mild immunodeficiency compared to that in healthy non-HIV people.

Methods

In total, 72 PLWH that were asymptomatic or with mild immunodeficiency (CD4 counts ≥200/mm3) and suppressed virology, and 362 healthcare workers of our hospital were enrolled. None of the participants had a history of SARS-CoV-2 infection. They received mRNA-1273 and ChAdOx1 vaccines. Anti-SARS-CoV-2 neutralizing and anti-Spike IgG antibodies, and SARS-CoV-2-specific T cell responses were evaluated.

Results

The standard two-shot regimen elicited lower responses in PLWH than the healthcare workers without HIV infection, although the difference was statistically insignificant. They had comparable levels of neutralizing and anti-Spike antibodies and comparable effector CD4+ and CD8+ T cell responses. The third shot boosted the SARS-CoV-2 immunity significantly more with better antibody responses and higher IFN-γ and IL-2 responses of the CD4+ and CD8+ T cells in PLWH compared to those without HIV. Upon in vitro stimulation with extracted Wuhan strain SARS-CoV-2 proteins, CD8+ T cells from PLWH after 3 shots had more durable effector responses than the non-HIV controls with extended time of stimulation.

Conclusion

This subtle difference between PLWH and non-HIV people implied immune exhaustion with two shots in non-HIV people. Slightly compromised immunity in PLWH indeed preserved the functional capacity for further response to the third shot or natural infection.

Murine cytotoxic CD4+ T cells in the tumor microenvironment are at a hyper-maturation stage of Th1 CD4+ T cells sustained by IL-12

The roles of tumor-infiltrating CD4+Foxp3- T cells are not well characterized due to their plasticity of differentiation, and varying levels of activation or exhaustion. To further clarify this issue, we used a model featuring subcutaneous murine colon cancer and analyzed the dynamic changes of phenotype and function of the tumor-associated CD4+ T-cell response. We found that, even at a late stage of tumor growth, the tumor-infiltrating CD4+Foxp3- T cells still expressed effector molecules, inflammatory cytokines and molecules that are expressed at reduced levels in exhausted cells. We used microarrays to examine the gene-expression profiles of different subsets of CD4+ T cells and revealed that the tumor-infiltrating CD4+Foxp3- T cells expressed not only type 1 helper (Th1) cytokines, but also cytolytic granules such as those encoded by Gzmb and Prf1. In contrast to CD4+ regulatory T cells, these cells exclusively co-expressed natural killer receptor markers and cytolytic molecules as shown by flow-cytometry studies. We used an ex vivo killing assay and proved that they could directly suppress CT26 tumor cells through granzyme B and perforin. Finally, we used pathway analysis and ex vivo stimulation to confirm that the CD4+Foxp3- T cells expressed higher levels of IL12rb1 genes and were activated by the IL-12/IL-27 pathway. In conclusion, this work finds that, in late-stage tumors, the tumor-infiltrating lymphocyte population of CD4+ cells harbored a sustained, hyper-maturated Th1 status with cytotoxic function supported by IL-12.

An IL-17-EGFR-TRAF4 axis contributes to the alleviation of lung inflammation in severe influenza

Excessive inflammation is a postulated cause of severe disease and death in respiratory virus infections. In response to severe influenza virus infection, adoptively transferred naïve hemagglutinin-specific CD4⁺ T cells from CD4⁺ TCR-transgenic 6.5 mice drive an IFN-γ-producing Th1 response in wild-type mice. It helps in virus clearance but also causes collateral damage and disease aggravation. The donor 6.5 mice have all the CD4⁺ T cells with TCR specificity toward influenza hemagglutinin. Still, the infected 6.5 mice do not suffer from robust inflammation and grave outcome. The initial Th1 response wanes with time, and a prominent Th17 response of recent thymic emigrants alleviates inflammation and bestows protection in 6.5 mice. Our results suggest that viral neuraminidase-activated TGF-β of the Th1 cells guides the Th17 evolution, and IL-17 signaling through the non-canonical IL-17 receptor EGFR activates the scaffold protein TRAF4 more than TRAF6 during alleviation of lung inflammation in severe influenza.

The origin of regulatory from the effector cells in LAG-3-marked Th1 immunity against severe influenza virus infection

In severe respiratory virus infections, including influenza, an exaggerated host immune response has been linked to the severe disease and death. Control of the overwhelming immune response is thus essential. Efforts with broad-spectrum immunosuppressive agents such as steroids are disappointing. A better understanding of host immune response using animal experimental system is required to avoid undesired outcome of experimental manipulation. Following severe influenza virus infection in influenza hemagglutinin antigen-specific transgenic mouse experimental model, step-wise evolving cells from a pool of naïve hemagglutinin-specific CD4⁺ T cells were studied for phenotypic, genomic, and functional characterization in vivo. Naïve CD4⁺ T cells respond with Th1 commitment in the absolute majority. They first develop into LAG-3^Med IFN-γ-secreting Th1 effectors and then evolve into LAG-3^High IFN-γ-not-secreting regulators with increasing LAG-3 expression upon continuous activation and cell division. The LAG-3^Med IFN-γ-secreting effectors contribute to inflammation, boost inflammatory response of cognate antigen-specific CD8⁺ T cells, and aggravate the disease despite facilitated virus clearance. In contrast, LAG-3^High regulators do not contribute to inflammation, suppress CD8⁺ T cell inflammatory response, alleviate lung pathology, and ameliorate the disease with preserved virus clearance. Moderated CD8⁺ T cells retain proliferative capacity, and persist beyond virus clearance. Such moderation is distinct from Foxp-3⁺ regulator-mediated suppression, which suppresses proliferative and inflammatory responses of the CD8⁺ T cells and impairs virus clearance with inflammation alleviation. Origin of regulatory from the effector cells of LAG-3-marked Th1 immunity alleviates lung inflammation without impairment of virus eradication.

Titers and breadth of neutralizing antibodies against SARS-CoV-2 variants after heterologous booster vaccination in health care workers primed with two doses of ChAdOx1 nCov-19: A single-blinded, randomized clinical trial

OBJECTIVES

We conducted a single-blinded, randomized trial to evaluate the safety, reactogenicity, and immunogenicity of heterologous booster vaccination in health care workers (HCW) who had received two doses of ChAdOx1 nCov-19.

METHODS

HCW who had at least 90 days after the second dose were enrolled to receive one of the four vaccines: BNT162b2 (30 μg), half-dose mRNA-1273 (50 μg), mRNA-1273 (100 μg), and MVC-COV1901 (15 μg). The primary outcomes were humoral and cellular immunogenicity and secondary outcomes assessed safety and reactogenicity at 28 days post-booster.

RESULTS

MVC-COV1901 Three hundred and forty HCW were enrolled: 83 received BNT162b2 (2 excluded), 85 half-dose mRNA-1273, 85 mRNA-1273, and 85 MVC-COV1901. mRNA vaccines had more reactogenicity than protein vaccine. The fold-rise of anti-spike IgG geometric mean titer was 8.4 (95% CI 6.8-10.4) for MVC-COV1901, 32.2 (27.2-38.1) for BNT162b2, 47.6 (40.8-55.6) for half-dose mRNA-1273 and 63.2 (53.6-74.6) for mRNA-1273. The live virus microneutralization assays (LVMNA) against the wild type, alpha and delta variants were consistent with anti-spike IgG for all booster vaccines. The LVMNA in the four groups against omicron BA.1 variant were 6.4 to 13.5 times lower than those against the wild type. All booster vaccines induced a comparable T cell response.

CONCLUSIONS

Third dose booster not only increases neutralizing antibody titer but also enhances antibody breadth against SARS-CoV-2 variants. mRNA vaccines are preferred booster vaccines for those who received primary series of ChAdOx1 nCov-19.

National safety surveillance of quadrivalent recombinant influenza vaccine in Taiwan during NH 20/21

BACKGROUND

During the COVID-19 pandemic, the need for influenza vaccine significantly increased in the initial weeks of the 2020-2021 influenza vaccination campaign season in Taiwan. To meet this demand, the Taiwanese government therefore purchased additional influenza vaccines via special import, including 350,000 doses of quadrivalent recombinant influenza vaccines (RIV4, Flublok Quadrivalent). Approved in the United States since 2016, there were limited numbers of published studies regarding RIV4 outside America. We utilized the national passive surveillance system consisting adverse event (AE) reports following RIV4 immunization to describe its safety profiles in Taiwan.

METHODS

We obtained the database from the Taiwan National Adverse Drugs Reactions Reporting System and collected reports from January 2021 to July 2021, which was at least one month after RIV4 immunization. AE reporting rates were calculated based on the total administered doses.

RESULTS

Eight AEs were reported among 200,287 administered doses, which led to a reporting rate of 3.99 AEs per 100,000 doses administered. The mean age of the reported individuals were 47.53 years, and women (75%) were the predominant gender. Most adverse events started within the first day after immunization, with one reported as starting 4 days after vaccination. Among the 8 cases, 75% (n = 6) were non-serious and the most common symptoms were erythematous skin rashes with pruritus. Two cases were listed as serious based on the criteria of "other clinically significant medical conditions", but neither was judged to have a causal relationship with RIV4 immunization.

CONCLUSION

The Taiwan national passive surveillance data supported the safety profiles of RIV4 in Taiwan population.

A multitope SARS-COV-2 vaccine provides long-lasting B cell and T cell immunity against Delta and Omicron variants

Background

The Delta and Omicron variants of SARS-CoV-2 are currently responsible for breakthrough infections due to waning immunity. We report phase I/II trial results of UB-612, a multitope subunit vaccine containing S1-RBD-sFc protein and rationally designed promiscuous peptides representing sarbecovirus conserved helper T cell and cytotoxic T lymphocyte epitopes on the nucleocapsid (N), membrane (M), and spike (S2) proteins.

Method

We conducted a phase I primary 2-dose (28 days apart) trial of 10, 30, or 100 μg UB-612 in 60 healthy young adults 20 to 55 years old, and 50 of them were boosted with 100 μg of UB-612 approximately 7 to 9 months after the second dose. A separate placebo-controlled and randomized phase II study was conducted with 2 doses of 100 μg of UB-612 (n = 3,875, 18–85 years old). We evaluated interim safety and immunogenicity of phase I until 14 days after the third (booster) dose and of phase II until 28 days after the second dose.

Results

No vaccine-related serious adverse events were recorded. The most common solicited adverse events were injection site pain and fatigue, mostly mild and transient. In both trials, UB-612 elicited respective neutralizing antibody titers similar to a panel of human convalescent sera. The most striking findings were long-lasting virus-neutralizing antibodies and broad T cell immunity against SARS-CoV-2 variants of concern (VoCs), including Delta and Omicron, and a strong booster-recalled memory immunity with high cross-reactive neutralizing titers against the Delta and Omicron VoCs.

Conclusion

UB-612 has presented a favorable safety profile, potent booster effect against VoCs, and long-lasting B and broad T cell immunity that warrants further development for both primary immunization and heterologous boosting of other COVID-19 vaccines.

Trial Registration

ClinicalTrials.gov: NCT04545749, NCT04773067, and NCT04967742.

Funding

UBI Asia, Vaxxinity Inc., and Taiwan Centers for Disease Control, Ministry of Health and Welfare.

Inhaled Zanamivir versus Oral Oseltamivir to Prevent Influenza-related Hospitalization or Death: a Nationwide Population-based Quasi-experimental Study

BACKGROUND

Individual patient data meta-analyses of randomized controlled trials show that early oseltamivir treatment for influenza cut risk of pneumonia and hospitalization by 44% and 63%, respectively. However, data are lacking for inhaled zanamivir on its effectiveness to prevent hospitalization and death.

METHODS

This nationwide, population-based cohort study included all outpatients treated with inhaled zanamivir or oral oseltamivir, within 48 hours after a clinical diagnosis of influenza, before and after the rollout of inhaled zanamivir as the first-line antiviral in Taiwan. The main outcome is influenza-related hospitalization or death within 14 days, ascertained using Taiwan national health insurance database and national death registry, respectively. Those developed the outcome within 2 days were excluded from analyses. Propensity score stratification was used to control confounding from covariates.

RESULTS

A total of 865,032 eligible influenza outpatients were included in the analysis. The risk of developing the main outcome (adjusted hazard ratio [aHR]: 1.01, 95% confidence interval [CI]: 0.96 to 1.06) did not differ between inhaled zanamivir group (n = 595,897, 68.9%, the reference) and oral oseltamivir group (n = 269,135, 31.1%). Prespecified analysis on high-risk subgroups further showed that inhaled zanamivir is not inferior to oral oseltamivir in either >65 years elderly patients (aHR: 1.14, 95% CI: 1.05 to 1.25) or patients with chronic lung diseases (aHR: 1.23, 95% CI: 1.08 to 1.41).

CONCLUSION

Inhaled zanamivir is not inferior to oral oseltamivir as outpatient treatment to prevent influenza-related hospitalization or death, for patients whose conditions do not require hospitalization within 2 days.

Demineralization Inhibition by Two Calcium-releasing Restorative Materials

OBJECTIVE

To compare the ability of two calcium-releasing restorative materials to inhibit root dentin demineralization in an artificial caries model.

METHODS AND MATERIALS

Preparations were made at the cementum-enamel junction of extracted human molars (40, n=10/material) and restored with two calcium-releasing materials (Experimental composite, Pulpdent Corporation and Cention N, Ivoclar Vivadent), a resin composite (Filtek Supreme Ultra, 3M Oral Care), and a resin-modified glass ionomer (RMGI) (Fuji II LC, GC). All materials (other than the RMGI) were used with an adhesive (Scotchbond Universal Adhesive, 3M Oral Care) in the self-etch mode, which was light cured for 10 seconds. All restorative materials were light cured in 2-mm increments for 20 seconds and then finished with a polishing disc. Teeth were incubated (37°C) for 24 hours in water. An acid-resistant varnish was painted onto the teeth around the restoration, leaving a 2-mm border of uncovered tooth. A demineralization solution composed of 0.1 M lactic acid, 3 mM Ca3(PO4)2, 0.1% thymol, and NaOH (to adjust pH=4.5), and a remineralization solution composed of 1.5 mM Ca, 0.9 mM P, and 20 mM Tris(hydroxymethyl)-aminomethane (pH=7.0) were prepared. Specimens were placed in the demineralization solution for 4 hours, followed by the remineralization solution for 20 hours and cycled daily for 30 days. The specimens were embedded, sectioned into 100-μm sections, and the interface between the restorative material and root dentin was viewed with polarized light microscopy. A line was drawn parallel with the zone of demineralization for each tooth. The area of "inhibition" (defined as the area external to the line) or "wall lesion" (defined as the area internal to the line) was measured with image evaluation software. Areas of inhibition were measured as positive values, and areas of wall lesions were measured as negative areas.

RESULTS

A one-way analysis of variance (ANOVA) found significant differences between materials for "inhibition/wall lesion" areas in root dentin (p<0.001). Tukey post hoc analysis ranked materials (μm2, mean ±SD): Fuji II LC (5412±2754) > Cention N (2768±1576) and experimental composite (1484±1585) > Filtek Supreme Ultra (-1119±1029).

CONCLUSION

The experimental composite and Cention N materials (used with an adhesive) showed net areas of inhibition greater than a reference resin composite, albeit at a lower level than a reference RMGI material (used with no adhesive).

Bacterial factors required for Streptococcus pneumoniae coinfection with influenza A virus

BACKGROUND

Streptococcus pneumoniae is a common cause of post-influenza secondary bacterial infection, which results in excessive morbidity and mortality. Although 13-valent pneumococcal conjugate vaccine (PCV13) vaccination programs have decreased the incidence of pneumococcal pneumonia, PCV13 failed to prevent serotype 3 pneumococcal disease as effectively as other vaccine serotypes. We aimed to investigate the mechanisms underlying the co-pathogenesis of influenza virus and serotype 3 pneumococci.

METHODS

We carried out a genome-wide screening of a serotype 3 S. pneumoniae transposon insertion mutant library in a mouse model of coinfection with influenza A virus (IAV) to identify the bacterial factors required for this synergism.

RESULTS

Direct, high-throughput sequencing of transposon insertion sites identified 24 genes required for both coinfection and bacterial infection alone. Targeted deletion of the putative aminotransferase (PA) gene decreased bacterial growth, which was restored by supplementation with methionine. The bacterial burden in a coinfection with the PA gene deletion mutant and IAV in the lung was lower than that in a coinfection with wild-type pneumococcus and IAV, but was significantly higher than that in an infection with the PA gene deletion mutant alone. These data suggest that IAV infection alters host metabolism to benefit pneumococcal fitness and confer higher susceptibility to pneumococcal infection. We further demonstrated that bacterial growth was increased by supplementation with methionine or IAV-infected mouse lung homogenates.

CONCLUSIONS

The data indicates that modulation of host metabolism during IAV infection may serve as a potential therapeutic intervention against secondary bacterial infections caused by serotype 3 pneumococci during IAV outbreaks in the future.

Genomic Insight into the Spread of Meropenem-Resistant Streptococcus pneumoniae Spain23F-ST81, Taiwan

Incidence of invasive pneumococcal disease caused by antimicrobial-resistant Streptococcus pneumoniae types not included in pneumococcal conjugate vaccines has increased, including a penicillin- and meropenem-resistant serotype 15A-ST63 clone in Japan. During 2013-2017, we collected 206 invasive pneumococcal isolates in Taiwan for penicillin and meropenem susceptibility testing. We found serotypes 15B/C-ST83 and 15A-ST63 were the most prevalent penicillin- and meropenem-resistant clones. A transformation study confirmed that penicillin-binding protein (PBP) 2b was the primary meropenem resistance determinant, and PBP1a was essential for high-level resistance. The rate of serotype 15B/C-ST83 increased during the study. All 15B/C-ST83 isolates showed an ermB macrolide resistance genotype. Prediction analysis of recombination sites revealed 12 recombination regions in 15B/C-ST83 compared with the S. pneumoniae Spain^23F-ST81 genome. Pneumococcal clones rapidly recombine to acquire survival advantages and undergo local expansion under the selective pressure exerted by vaccines and antimicrobial drugs. The spread of 15B/C-ST83 is alarming for countries with high antimicrobial pressure.

Relative COVID-19 Viral Persistence and Antibody Kinetics

A total of 15 RT-PCR confirmed COVID-19 patients were admitted to our hospital during the in-itial outbreak in Taiwan. The average time of virus clearance was delayed in seven patients, 24.14 ± 4.33 days compared to 10.25 ± 0.56 days post-symptom onset (PSO) in the other eight pa-tients. There was strong antibody response in patients with viral persistence at the pharynx, with peak values of serum antibody 677.2 ± 217.8 vs. 76.70 ± 32.11 in patients with delayed versus rapid virus clearance. The patients with delayed viral clearance had excessive antibodies of compromised quality in an early stage with the delay in peak virus neutralization efficacy, 34.14 ± 7.15 versus 12.50 ± 2.35 days PSO in patients with rapid virus clearance. Weak antibody re-sponse of patients with rapid viral clearance was also effective, with substantial and comparable neutralization efficacy, 35.70 ± 8.78 versus 41.37 ± 11.49 of patients with delayed virus clearance. Human Cytokine 48-Plex Screening of the serial sera samples revealed elevated concentrations of proinflammatory cytokines and chemokines in a deceased patient with delayed virus clear-ance and severe disease. The levels were comparatively less in the other two patients who suf-fered from severe disease but eventually survived.

Association of capsular types with carbapenem resistance, disease severity, and mortality in Acinetobacter baumannii

Acinetobacter baumannii emerged as one of the most important pathogens that causes nosocomial infections due to its increased multidrug resistance. Identifying capsular epidemiology in A. baumannii can aid in the development of effective treatments and preventive measures against this emerging pathogen. Here we established a wzc-based method, and combined it with wzy-PCR to determine capsular types of A. baumannii causing nosocomial bacteraemia collected at two medical centres in Taiwan from 2015 to 2017. Among the 237 patients with A. baumannii bacteraemia, 98 (41.4%) isolates were resistant to carbapenems. Four prevalent capsular types (KL2, KL10, KL22, and KL52) accounted for 84.7% of carbapenem-resistant A. baumannii (CRAB) and 12.2% of non-CRAB. The rate of pneumonia, intensive care unit admission, APACHE II score, and Pitt bacteraemia score were higher in patients with KL2/10/22/52 infection than in those with non-KL2/10/22/52 infection. Patients with KL2/10/22/52 infection and patients with CRAB infection have a higher cumulative incidence of attributable and all-cause in-hospital 30-day mortality. On multivariate analysis, appropriate empirical antimicrobial therapy within 24 h was associated with a lower risk of 30-day attributable mortality in the KL2/10/22/52 isolates (odds ratio = 0.19, 95% CI: 0.06–0.66, p = 0.008) but not in non-KL2/10/22/52 isolates. Early recognition of carbapenem resistance-associated capsular types may help clinicians to promptly implement appropriate antimicrobial therapy for improving the outcomes in patients with CRAB bacteraemia.

Role of IL-17-EGFR axis in alleviated lung inflammation and recovery during the late phase of acute influenza virus infection

Influenza hemagglutinin (HA)-specific T-Cell-Receptor (TCR) transgenic mice sustain the influenza virus infection of an inoculum size which is fatal in wild type mice. There is a prominent IL-17 response of the HA-specific TCR transgenic CD4+ T cells in late phase of infection in the transgenic mice. We have demonstrated that the late phase IL-17 response is a de novo response of naïve T cells under guidance of the Th1 cells with influenza viral neuraminidase-activated TGF-β. There is also a late phase up-regulation of epidermal growth factor receptor (EGFR) on the transgenic CD4+ T cells in the lungs. EGFR inhibition with Gefitinib resulted in impaired sustainability of the infection of the transgenic mice. They suffered from profound body weight loss and severe disease with significant mortality. IL-17-induced EGFR-mediated signaling cascade has been documented in skin stem cells that are involved in wound healing. We will further dissect the role of this cascade in alleviation of lung inflammation and recovery from the disease during the late phase of acute influenza virus infection.

Role of Pneumococcal NanC in the Severe Disease of Streptococcus pneumoniae Superinfection with Influenza

Bacterial superinfection aggravates the disease of influenza. Streptococcus pneumoniae is the most common bacterial pathogen. Synergistic virulence has been demonstrated between influenza neuraminidase and pneumococcal NanA and NanB. NanC, the other pneumococcal neuraminidase infrequently present in clinical isolates, is not well characterized. In this study, we report that superinfection with a NanC-negative pneumococcus strain suppresses anti-influenza immunity and impairs viral clearance with higher TGF-β activation in mice. Bacterial load in the lungs also increases as the host immunity is suppressed. NanC-positive isogenic mutant reverses wild type S. pneumoniae-mediated immune suppression and facilitates virus clearance. However, it causes more severe disease as the augmented inflammation causes collateral damage. Both virus-mediated damage and immune response-mediated inflammation are important for pathogenesis of severe influenza. Inflammation may be more critical than virus-mediated damage in influenza with bacterial superinfection.

[Clinical analysis of 11 cases of sub-acute arsenic poisoning]

Objective: To investigate the clinical manifestations, treatments and prognosis of subacute arsenic poisoning. Methods: In January 2020, a retrospective analysis was carried out on 11 patients hospitalized with subacute arsenic poisoning caused by arsenic contaminated drinking water. We observed manifestations, treatments and prognosis. Results: The main clinical presentations of subacute arsenic poisoningin were gastroenteritis in early phase, some of them had other organ damage, such as skin, blood, liver, kidney, cardiovascular and so on. The later phase was mainly peripheral nervous system damage. The treatment was mainly to chelate arsenic, protect target organs and treat toxic peripheral neuropathy. Most were significantly recoveried, but the recovery of severe toxic peripheral neuropathy was tardy. Conclusion: Acute gastroenteritis is the mainly early manifestation of subacute arsenic poisoning caused by digestive tract, and toxic peripheral neuropathy in the later phase. The prognosis is good, but the recovery of severe toxic peripheral neuropathy is tardy.

Does Antimicrobial Therapy Affect Mortality of Patients with Carbapenem-Resistant Klebsiella pneumoniae Bacteriuria? A Nationwide Multicenter Study in Taiwan

Few clinical studies have previously discussed patients with carbapenem-resistant Klebsiella pneumoniae (CRKP) bacteriuria. This study aimed to assess the effect of antimicrobial therapy on the mortality of patients with CRKP bacteriuria. Hospitalized adults with CRKP bacteriuria were enrolled retrospectively from 16 hospitals in Taiwan during 2013 and 2014. Critically ill patients were defined as those with an Acute Physiology and Chronic Health Evaluation (APACHE) II score ≥ 20. Multivariate Cox regression analysis was used to determine independent risk factors for 14- and 28-day mortality. Of 107 patients with CRKP bacteriuria, the 14-day and 28-day mortality was 14.0% and 25.2%, respectively. Thirty-three patients received appropriate antimicrobial therapy. In the multivariate Cox regression analysis, the APACHE II score ≥ 20 was the only independent risk factor for 14-day mortality (hazard ratio [HR]: 6.15, p = 0.024). APACHE II score ≥ 20 (HR: 3.05, p = 0.018) and male sex (HR: 2.57, p = 0.037) were associated with 28-day mortality. Among critically ill patients with CRKP bacteriuria, appropriate antimicrobial therapy was not associated with 14-day or 28-day survival. In conclusion, in patients with CRKP bacteriuria, the use of appropriate antimicrobial therapy was not an independent factor associated with reduced mortality. Our findings may inform future antibiotic stewardship interventions for bacteriuria caused by multidrug resistant pathogens.

Correlation between Negative Rapid Influenza Diagnostic Test and Severe Disease in Hospitalized Adults with Laboratory-Confirmed Influenza Virus Infection

False-negative rapid influenza diagnostic test (RIDT) results could mislead physicians to exclude an influenza diagnosis. We sought to evaluate the association between negative RIDT and intensive care unit (ICU) admission. We reviewed data from hospitalized adults with laboratory-confirmed influenza virus infections in a tertiary referral hospital in Taiwan from July 2009 to February 2011. The diagnosis was documented by real-time PCR or virus culture. Of 134 hospitalized adults infected with influenza virus, 38 (28%) were admitted to the ICU. Compared with RIDT-positive patients, the percentage of ICU admission was significantly higher among RIDT-negative patients (46% versus 13%, P < 0.001). The RIDT-negative patients had higher percentages of lower respiratory symptoms and more chest radiograph infiltrates. The time interval between the RIDT and antiviral treatment was longer in RIDT-negative than RIDT-positive patients (1.94 days versus 0.03 days, P < 0.001). Among patients presenting with mild illness, only a negative RIDT and delayed antiviral treatment were associated with ICU admission after adjusting for potential confounding factors. To conclude, patients with a negative RIDT were more likely to have severe disease and a delay in initiating antiviral treatment. Our findings should help improve treatment outcomes of hospitalized patients with influenza infection.

Therapeutic Role of Inducible Nitric Oxide Synthase Expressing Myeloid-Derived Suppressor Cells in Acetaminophen-Induced Murine Liver Failure

Background

Acetaminophen (APAP) overdose is one of the major etiologies of liver failure. Hepatocyte necrosis induced by toxic metabolites of APAP can activate proinflammatory responses, including elastase-expressing neutrophils, to exacerbate liver injury. Myeloid-derived suppressor cells (MDSCs) increased in inflammation can inhibit proinflammatory responses. Our aim is to investigate the role of MDSC in APAP-induced liver failure and the possible therapeutic application.

Methods

BLAB/c mice were injected with a sublethal/lethal dose of APAP as the murine model of liver failure. MDSCs were defined as CD11b⁺Gr-1⁺ cells with the ability of T-cell suppression.

Results

A sublethal challenge of APAP could increase the intrahepatic MDSC and protect mice against subsequent lethal challenge of APAP, lipopolysaccharide (LPS)/D-galatosamine or concanavalin A. This protection was lost if MDSCs were depleted and inducible nitric oxide synthase (iNOS) was the key molecule in this MDSC-mediated protection. Taking advantage of these observations, different bone marrow-derived MDSCs (BM-MDSCs) were generated. Among different cytokine-treated BM-MDSCs, tumor necrosis factor alpha/LPS-primed MDSCs (TNF-α/LPS MDSCs) had the strongest liver-protection ability after adoptive transfer. Further mechanistic explorations showed, iNOS-expressing TNF-α/LPS MDSCs induced the apoptosis of activated neutrophil and decreased the intrahepatic infiltration of elastase-expressing neutrophil. Moreover, we generated MDSCs from human peripheral blood mononuclear cells (PBMCs) with similar phenotype.

Conclusion

We demonstrated the protective role of MDSCs and therapeutic effect of TNF-α/LPS MDSCs in APAP-induced liver failure. MDSC might protect against the APAP-induced liver failure by reducing the intrahepatic infiltration of activated neutrophil to limit inflammation. Therefore, a therapeutic role of MDSCs for APAP-induced liver failure was proposed.

Brain Computed Tomography in Stimulant Poisoning with Altered Consciousness

BACKGROUND

Stimulant poisoning frequently causes altered mental status (AMS) and can result in severe cerebral vascular complications. The role of noncontrast brain computed tomography (CT) in acute stimulant-poisoned patients presenting with AMS remains unclear.

OBJECTIVES

We examined the results and impacts of brain CT in acute stimulant-poisoned patients with AMS.

METHODS

We performed a retrospective single-center study that included all adult patients who presented to the emergency department with stimulant poisoning and AMS (Glasgow coma scale [GCS] score <15) between January 1, 2010 and December 31, 2017. Patients who had concomitant head trauma or who presented with focal neurologic symptoms were excluded. The primary outcome was the rate of acute abnormalities on brain CT. The secondary outcomes were to identify factors that affected the decision to perform brain CT in stimulant-poisoned patients with AMS and whether obtaining the brain CT scan itself affected the patients' prognoses.

RESULTS

The analysis included 66 patients, of whom 6 died from the poisoning. Noncontrast brain CT was performed in 31 patients and none had acute abnormalities. Patients who underwent brain CT were found to have worse GCS scores, higher body temperatures, higher intubation rates, higher admission rates, longer admission periods and intensive care unit stays, and a higher mortality rate. After adjusting for the propensity score, performing brain CT itself did not independently affect the patients' clinical outcomes.

CONCLUSIONS

Nontrauma stimulant-poisoned patients presenting with AMS and without focal neurologic symptoms were unlikely to have acute abnormalities on brain CT. Patients who underwent brain CT scans had worse consciousness and greater disease severity.

LAG-3 marks effector to regulatory evolution of Th1 immunity in influenza

Naïve CD4+ T cells respond in influenza with T-bet expression, a transcription factor up-regulated with Th1 commitment. We report concomitant LAG-3 expression on these Th1 committed cells with evolution into regulatory T cells. LAG-3 expression increases with activation as revealed by CFSE cell division study. Cells with moderate LAG-3 expression produce IFN-γ and contribute to inflammation and disease. They no longer produce IFN-γ with higher LAG-3 expression upon further activation. High LAG-3 cells suppress and decouple effector function from the preserved proliferation of CD8+ T cells. They restrain inflammation with facilitated viral clearance and ameliorate the disease of severe influenza. Foxp-3+CD4+ T cells suppress both effector and proliferative responses with impaired viral clearance and they are less potent in disease amelioration. Principal component analysis of genome-wide expression further confirmed the stepwise evolution from effector to regulatory T cells. Regulatory genes are up-regulated progressively from LAG-3Neg to LAG-3Med and to LAG-3High cells.

Bacterial neuraminidase C reverts neuraminidase A and B mediated suppression of anti-influenza immunity and aggravates the disease in influenza with pneumococcal superinfection

Bacterial superinfection aggravates the disease of influenza virus infection. Streptococcus pneumoniae is a frequently encountered bacterial pathogen. Superinfection with neuraminidase (Nan) C deficient wild type pneumococcus, which expresses NanA and NanB only, suppressed antigen-specific anti-influenza immunity, with impaired viral clearance. There was augmented TGF-β activation in the lung-infiltrating influenza hemagglutinin (HA)-specific CD4+ T cells. Mice suffered from exacerbated disease and died with higher virus loads in the lung. We modified this wild type strain with NanC insertion. This modified strain expresses all neuraminidases A, B and C. Superinfection with this NanC inserted pneumococcus reverted the immune-suppressive effect of the wild type pneumococcus with NanA and NanB only. There were augmented inflammatory cytokines IFN-γ and TNF-α production and suppressed TGF-β activation in the lung-infiltrating influenza HA-specific CD4+ T cells. The pro-inflammatory response enhanced viral clearance. Even the virus eradication is enhanced, the mice actually suffered from even more severe disease. Our results demonstrated the important role of NanC-mediated inflammation in the disease of severe influenza with pneumococcal superinfection.

Th1 guided evolution of protective de novo Th17 response in severe influenza

The 6.5 CD4+ T cell receptor (TCR) transgenic mice have a monotonous CD4+ TCR which responds to the hemagglutinin (HA) antigen of PR8 influenza virus. Naive 6.5 CD4+ T cells adoptively transferred into wild type mice were activated by PR8 influenza virus with Th1 response. With PR8 influenza virus infection, all CD4+ T cells in 6.5 mice were activated and they were predominantly Th1 in phenotype at the early phase of infection and Th17 at the late phase. Th1 effector responses made infected mice sick and even succumb to death. The 6.5 mice were sicker at the early phase but recovered with better survival at last. IL-17KO 6.5 mice cannot display Th17 responses and lost the survival benefit as well. IL-17 supplement at the late phase of infection enhanced survival of wild type mice with PR8 influenza virus infection. With consecutive two adoptive transfers of naive 6.5 CD4+ T cells, 6.5 CD4+ T cells of the first transfer evolved into Th1 cells but 6.5 CD4+ T cells of the second transfer demonstrated a de novoTh17 response. Thymectomy or aging in 6.5 mice limited the thymic output of naive 6.5 CD4+ T cells and diminished the Th17 response. Viral neuraminidase activated TGF-β in the Th1 6.5 CD4+ T cells at the early phase. T-bet dominance was altered with excessive ROR-γt activation in the following responding 6.5 CD4+ T cells. They have substantial IL-17 with restrained IFN-γ production. We demonstrated a Th1 guided evolution of protective Th17 response in severe influenza.

Methicillin-resistant Staphylococcus aureus nasal colonization among HIV-infected patients in Taiwan: prevalence, molecular characteristics and associated factors with nasal carriage

Background

To evaluate nasal carriage, antibiotic susceptibility and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA), as well as the risk factors of MRSA colonization, in human immunodeficiency virus (HIV)-infected patients in northern Taiwan.

Methods

From September 2014 to November 2015, HIV-infected patients seeking outpatient care at four hospitals were eligible for this study. A nasal specimen was obtained from each subject for the detection of S. aureus and a questionnaire was completed by each subject. MRSA isolates once identified were characterized.

Results

Of 553 patients surveyed, methicillin-susceptible S. aureus (MSSA) was detected in 119 subjects (21.5%) and MRSA in 19 subjects (3.4%). Female gender, injection drug use, smoking, hepatitis C virus carrier, cancer and antibiotic use within 1 year were positively associated with MRSA colonization. By multivariate analysis, only cancer (adjust odds ratio (aOR) 7.78, [95% confidence interval (CI), 1.909–31.731]) and antibiotic use within 1 year (aOR 3.89, [95% CI, 1.219–12.433]) were significantly associated with MRSA colonization. Ten isolates were characterized as sequence type (ST) 59/staphylococcal chromosome cassette (SCC) IV or V_T, endemic community strains in Taiwan, four isolates as ST 8/SCCmec IV (USA 300) and one isolate as ST 239/SCCmec IIIA, a hospital strain. All the community-associated MRSA isolates were susceptible to trimethoprim-sulfamethoxazole (TMP-SMX).

Conclusions

Nasal MRSA carriage in HIV-infected patients seeking outpatient care was low (3.4%) in northern Taiwan. Most of the colonizing isolates were genetically endemic community strains and exhibited high susceptibility to TMP-SMX and fluoroquinolones. Cancer and antibiotic use within 1 year were associated with MRSA colonization.

Effect of aloin on viral neuraminidase and hemagglutinin-specific T cell immunity in acute influenza

BACKGROUND

Millions of people are infected by the influenza virus worldwide every year. Current selections of anti-influenza agents are limited and their effectiveness and drug resistance are still of concern.

PURPOSE

Investigation on in vitro and in vivo effect of aloin from Aloe vera leaves against influenza virus infection.

METHODS

In vitro antiviral property of aloin was measured by plaque reduction assay in which MDCK cells were infected with oseltamivir-sensitive A(H1N1)pdm09, oseltamivir-resistant A(H1N1)pdm09, H1N1 or H3N2 influenza A or with influenza B viruses in the presence of aloin. In vivo activity was tested in H1N1 influenza virus infected mice. Aloin-mediated inhibition of influenza neuraminidase activity was tested by MUNANA assay. Aloin treatment-mediated modulation of anti-influenza immunity was tested by the study of hemagglutinin-specific T cells in vivo.

RESULTS

Aloin significantly reduced in vitro infection by all the tested strains of influenza viruses, including oseltamivir-resistant A(H1N1)pdm09 influenza viruses, with an average IC₅₀ value 91.83 ± 18.97 μM. In H1N1 influenza virus infected mice, aloin treatment (intraperitoneal, once daily for 5 days) reduced virus load in the lungs and attenuated body weight loss and mortality. Adjuvant aloin treatment also improved the outcome with delayed oseltamivir treatment. Aloin inhibited viral neuraminidase and impeded neuraminidase-mediated TGF-β activation. Viral neuraminidase mediated immune suppression with TGF-β was constrained and influenza hemagglutinin-specific T cell immunity was increased. There was more infiltration of hemagglutinin-specific CD4+ and CD8+ T cells in the lungs and their production of effector cytokines IFN-γ and TNF-α was boosted.

CONCLUSION

Aloin from Aloe vera leaves is a potent anti-influenza compound that inhibits viral neuraminidase activity, even of the oseltamivir-resistant influenza virus. With suppression of this virus machinery, aloin boosts host immunity with augmented hemagglutinin-specific T cell response to the infection. In addition, in the context of compromised benefit with delayed oseltamivir treatment, adjuvant aloin treatment ameliorates the disease and improves survival. Taken together, aloin has the potential to be further evaluated for clinical applications in human influenza.

P1569The Impact of Multidisciplinary Cardio-Oncology Program on the Cardiovascular Outcomes in Breast Cancer Patients

Background

Chemo- and target therapies may induce myocardial dysfunction and lead to poor prognoses. Early detection of minor myocardial dysfunction is important for the prevention of subsequent cardiotoxicity. Cardio-oncology is a multidisciplinary field focusing on managing and preventing cardiovascular complications in cancer patients. However, whether Cardio-oncology program truly makes difference in cardiovascular outcomes remains unknown. Herein, we are sharing our experiences in our Medical Center.

Methods

Since 2014 till 2017, we recruited 154 patients with newly diagnosed breast cancer preparing for Epirubicin therapy. Echocardiography, biomarkers, six minute walking distance and cardiovascular adverse events including new onset of hypertension, stroke, myocardial infarction (MI) and mortality were recorded at baseline, three months, six months and one year. Any functional decline was reported to oncologists for the consideration of changing regimens. Otherwise, cardiologists would be consulted for cardiovascular educations and therapies. The echocardiographic and clinical records of 450 breast patients receiving Epirubicin therapy during 2010 to 2013 were also collected as comparison.

Results

Compared with the ratio of 20% patients receiving echocardiography prior to 2014, the ratio increased to 100% since Cardio-Oncology program started. Also, the drop of left ventricular ejection fraction (LVEF) from 25% attenuated to 5%. Before Cardio-Oncology Program, there were 1.7% of new onset hypertension, 0.8% of MI, 0.8% of stroke and 16.8% of mortality. Conversely, after the program, there were only 0.6% of new onset hypertension while no other cardiovascular complications were reported. Furthermore, compared with previous reports of the effectiveness of Cardio-Oncology Program, our result also displayed a superior impact on the cardiovascular outcomes.

Conclusions

Collectively, through a comprehensive monitoring and an early intervention of myocardial dysfunction post chemotherapies, Cardio-Oncology Program truly decreased the cardiovascular complications in breast cancer patients.

Acknowledgement/Funding

Chi-Mei Medical Center

Clinical features, microbiological epidemiology and recommendations for management of cellulitis in extremity lymphedema

BACKGROUND

This high volume, single center study investigated the prevalence, bacterial epidemiology, and responsiveness to antibiotic therapy of cellulitis in extremity lymphedema.

METHODS

From 2003 to 2018, cellulitis events from a cohort of 420 patients with extremity lymphedema were reviewed. Demographics, lymphedema grading, symptoms, inflammatory markers, cultures and antibiotic therapy regimens were compiled from cellulitis episodes data. Univariate and multivariate analyses were performed for detailed analysis.

RESULTS

A total of 131 separate episodes of cellulitis were recorded from 43 (81.1%) lower limb and 10 (19.9%) upper limb lymphedema patients. The prevalence and recurrence rates for cellulitis in lymphedema patients were 12.6% (53 of 420) and 56.6% (30 of 53), respectively. The most common findings were increased limb circumference (127 of 131; 96.9%) and abnormal C-reactive protein (CRP) level (86 of 113; 76.1%). Blood cultures were obtained in 79 (60.3%) incidents, with 9 (11.4%) returning positive. Streptococcus agalactiae was the most isolated bacterium (5 of 9; 55.5%).

CONCLUSIONS

The cellulitis prevalence and recurrence rate in extremity lymphedema were 12.6%, and 56.6%, respectively. Strongest indicators of cellulitis were increased affected limb circumference and elevated CRP level. Empiric antibiotic therapy began with coverage for Steptococcus species before broadening to anti-Methicillin-resistant Staphylococcus aureus and anti-Gram negatives if needed for effective treatment of extremity lymphedema cellulitis.

LAG-3+ induced regulatory T cells confer infectious tolerance with suppression of IFN-γ response decoupled from reserved proliferation

Induced regulatory T cells (iTreg) is an adaptive response in inflammation with disease processes such as infection, autoimmunity or cancer. A small number of iTreg may exert long-lasting regulation. Here we report the LAG-3+ iTreg transfer regulatory activity to the CD4+ T cells they suppress. This infectious propagation of regulatory activity exemplify a dominant immune regulation in vivo. Naïve hemagglutinin (HA) antigen-specific CD4+ T cells are induced to differentiate into IFN-γ competent effector T cells and then LAG-3+ Tregs in HA transgenic mice inherently expressing the cognate HA antigen. The LAG-3+ iTreg suppresses activation of effector function of cognate naïve CD4+ T cells in HA transgenic mice, with silenced IFN-γ machinery including STAT1 phosphorylation and T-bet induction. The LAG-3 iTreg suppressed, IFN-γ disarmed CD4+ T cells still proliferate and acquire LAG-3 expression on their surface in vivo. They become the next generation LAG-3+ iTregs with the ability of suppression of activation of effector function of cognate naïve CD4+ T cells in HA transgenic mice, with the same mechanism of silenced IFN-γ machinery. LAG-3+ iTreg exercises regulation in vivo by suppression of effector function decoupled from reserved proliferative response. The effector function suppressed CD4+ T cells still proliferate upon activation and acquire LAG-3+ iTreg phenotype, a reminiscence of the infectious tolerance proposed in 1970.

Concomitant effector and LAG-3 regulatory responses of Th1 committed cells in acute influenza

T-bet induced CD4+ T cells are committed to be IFN-γ competent Th1 cells. The Th1 response is essential for virus eradication, but is also a major cause of inflammation and disease aggravation in severe influenza. In our influenza hemagglutinin (HA) Ag-specific mouse experimental system, naïve CD4+ T cells respond to the infection with T-bet expression. However, they suppress cognate CD8+ T cell effector response-mediated inflammation and alleviate the disease. Here we report concomitant LAG-3 expression and IFN-γ competence in Th1 committed CD4+ T cells. LAG-3 expression increases with activation by virus as revealed by CFSE based cell division study. The Th1 committed cells with moderate LAG-3 expression produce IFN-γ and contribute to inflammation and aggravated disease. They can no longer produce IFN-γ with higher LAG-3 expression upon further activation. Th1 committed CD4+ T cells with high LAG-3 expression suppress cognate CD8+ T cells by decoupling their effector function from proliferative response, restrain lung inflammation and facilitate viral clearance. They are better than Foxp-3+HA-specific CD4+ T cells in disease amelioration. The Foxp-3+ cells suppress both effector function and proliferative response of CD8+ T cells. They moderate inflammation but impair viral clearance. Principal component analysis of genome-wide gene expression profiles further confirmed the stepwise evolution. Several regulatory function-associated genes such as Lag3, Pdcd1, Tigit, Ctla2a, Nr4a2, Klrc1, Rgs16, Sytl3, Il21, Il1r2 and Dusp4 are up-regulated graduallly as well from LAG-3Neg to LAG-3Med and LAG-3High cells.

Appropriate Treatment for Bloodstream Infections Due to Carbapenem-Resistant Klebsiella pneumoniae and Escherichia coli: A Nationwide Multicenter Study in Taiwan

Background

In a multicenter study from Taiwan, we aimed to investigate the outcome of patients who received different antimicrobial therapy in carbapenem-resistant Enterobacteriaceae bloodstream infections and proposed a new definition for tigecycline use.

Methods

Patients from 16 hospitals in Taiwan who received appropriate therapy for bloodstream infections due to carbapenem-resistant Klebsiella pneumoniae and Escherichia coli were enrolled in the study between January 2012 and June 2015. We used a cox proportional regression model for multivariate analysis to identify independent risk factors of 14-day mortality. Tigecycline was defined as appropriate when the isolates had a minimum inhibitory concentration (MIC) ≤0.5 mg/L, and we investigated whether tigecycline was associated with mortality among patients with monotherapy.

Results

Sixty-four cases with carbapenem-resistant K pneumoniae (n = 50) and E coli (n = 14) bloodstream infections were analyzed. Of the 64 isolates, 17 (26.6%) had genes that encoded carbapenemases. The 14-day mortality of these cases was 31.3%. In the multivariate analysis, Charlson Comorbidity Index (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.03–1.42; P = .022) and colistin monotherapy (HR, 5.57; 95% CI, 2.13–14.61; P < .001) were independently associated with 14-day mortality. Among the 55 patients with monotherapy, the 14-day mortality was 30.9% (n = 17). Tigecycline use was not associated with mortality in the multivariate analysis.

Conclusions

Tigecycline monotherapy was a choice if the strains exhibited MIC ≤0.5 mg/L, and colistin monotherapy was not suitable. Our findings can initiate additional clinical studies regarding the efficacy of tigecycline in carbapenem-resistant Enterobacteriaceae infections.

The clinical impact of patients with bloodstream infection with different groups of Viridans group streptococci by using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)

The accuracy of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for identifying viridans group streptococcus (VGS) was improving. However, the clinical impact of identifying VGS had not been well recognized. Our study had comprehensively studied the clinical manifestations and outcome of VGS blood stream infection by using MALDI-TOF MS for identification.This retrospective study enrolled 312 adult patients with a monomicrobial blood culture positive for VGS. Blood culture was examined through MALDI-TOF MS.The most common VGS species were the Streptococcus anginosus group (38.8%) and Streptococcus mitis group (22.8%). Most species showed resistance to erythromycin (35.6%), followed by clindamycin (25.3%) and penicillin (12.5%). Skin and soft tissue infection and biliary tract infection were significantly related to S. anginosus group bacteremia (P = .001 and P = .005, respectively). S. mitis group bacteremia was related to infective endocarditis and bacteremia with febrile neutropenia (P = .005 and P < .001, respectively). Infective endocarditis was also more likely associated with S. sanguinis group bacteremia (P = .009). S. anginosus group had less resistance rate to ampicillin, erythromycin, clindamycin, and ceftriaxone (P = .019, <.001, .001, and .046, respectively). A more staying in intensive care unit, underlying solid organ malignancy, and a shorter treatment duration were independent risk factors for 30-day mortality. This study comprehensively evaluated different VGS group and their clinical manifestations, infection sources, concomitant diseases, treatments, and outcomes. Categorizing VGS into different groups by MALDI-TOF MS could help clinical physicians well understand their clinical presentations.

Induction of liver-specific intrahepatic myeloid cells aggregation expands CD8 T cell and inhibits growth of murine hepatoma

Toll-Like Receptor 9 (TLR9) stimulation selectively triggers the formation of a cell cluster termed intrahepatic myeloid aggregation for T cell expansion" (iMATE) in a mouse chronic viral hepatitis model. iMATE expands cytotoxic T cells and controls viral hepatitis infection. The liver-specific immune response prompted this investigation of whether the effect could control tumor growth in the murine hepatic tumor model. Murine hepatic BNL cells were used to establish an orthotropic liver tumor model. We found that intravenous infusion of TLR 9 agonist, CpG oligodeoxynucleotide (ODN) induced iMATE formation in non-tumor parts of liver and suppressed the murine BNL tumor growth. The ratio of intra-tumor CD8+ T cells have increased after CpG ODN. These cells expressed higher levels of effector and checkpoint molecules, and produce more Th1 cytokine upon ex vivo stimulation. The CD11b+Ly6ChiLy6G - subset of CD11b+ myeloid cells in the tumor microenvironment has increased. Both CD11b+Ly6ChiLy6G - and CD11b+Ly6CloLy6G+ subsets expressed higher level of interferon-gamma post CpG ODN treatment, although still presented a suppressive phenotype. Their suppressive ability was decreased, instead, the targeted CD8+ T cell proliferation was promoted at a higher dose of CD11b+Ly6ChiLy6G- cells. The phenomenon was further proven in DEN induced liver tumor model. In conclusion, systemic CpG ODN treatment induced iMATE formation that expanded effector CD8+ T cells to control tumor growth in the mouse hepatic tumor model. This novel strategy provides a new rationale for liver-specific tumor immunotherapy.

Disease manifestations with immune alteration by bacterial neuraminidases in influenza virus infection with Streptococcus pneumoniae superinfection

Streptococcus pneumoniae often causes superinfection in influenza and exacerbates the disease with more severity and even mortality. In our influenza hemagglutinin (HA) antigen-specific transgenic mouse model, mice suffered from severe disease and died with increased virus titer and pathology in the lungs upon serotype-3 Streptococcus pneumoniae superinfection on day 4- post PR8 strain H1N1 influenza virus infection. Same dose viral or bacterial infection caused mild disease in control mice. Streptococcus pneumoniae supreinfection attenuated anti-influenza T cell immunity in the lungs. There was less clonotypic expansion, T-bet induction and effector cytokines IFN-γ and TNF-α production in HA-specific CD4+ T cells on day 2- and 3- post bacterial superinfection, with impaired viral clearance. Streptococcus pneumoniae strains with different combinations of bacterial neuraminidase (NA) demonstrated varied degrees of T cell immunity attenuation. Streptococcus pneumoniae with NA-B only was the most suppressive with up-regulated active TGF-β and down-regulated IFN-γ expression in HA-specific CD4+ T cells, followed by those with both NA-A and NA-B. Streptococcus pneumoniae with both NA-A and NA-B and inserted NA-C was least suppressive. With in vitro experiments, recombinant bacterial NA-A or NA-B augmented TGF-β and attenuated IFN-γ in HA-specific CD4+ T cells in overnight culture with PR8 virus. Recombinant bacterial NA-C mitigated TGF-β and increased IFN-γ in HA-specific CD4+ T cells. Our results demonestrates distinct immune alteration by different bacterial neuraminidases, which may play a significnt role of disease manifestation in influenza with bacterial superinfection.

Host antigen modulated anti-influenza immunity with antigen level dependent distinct mechanisms of severe influenza

Some healthy individuals suffer from severe disease and even mortality with the same strain of influenza virus that causes self-limited illnesses in the majority of people. This fact exemplifies the importance of host factors in influenza disease manifestation. Our C3-HA transgenic mice express hemagglutinin (HA) as a self-antigen that is identical to the HA of PR8 influenza virus. Compared to wild type mice, C3-HA mice incurred severe disease with PR8, but not with HA-mismatched influenza virus. Self-HA in C3-HA mice altered the immune response to the infection and impaired clearance of the influenza virus. However, different mechanisms contribute for exacerbated disease in C3-HA mice with different level of HA. In C3-HALow mice, low-level self-HA modulated HA specific immunity upon infection with less clonotypic expansion, T-bet induction and effector cytokines IFN-γ and TNF-α production of both HA-specific CD4+ and CD8+ T cells on day 4- post infection. The T cell activation status contracted further on day 7- post infection. Impaired immunity resulted in delayed virus clearance leading to severe disease and death. In C3-HAHigh mice, high-level self-HA also modulated impaired immunity and virus clearance on day 4- post infection. In contrast to further reduction on day 7- post infection in C3-HALow mice, the HA specific T cell immunity was higher on day 7- than day 4- post infection in C3-HAHigh mice. The boosted HA specific immunity resulted in severe disease with autoimmunity as a predominant feature in pathology. Our animal model exemplified the complicated interaction between cross-reactive self-antigen and influenza virus with severe disease as the results of antigen level dependent distinct mechanisms.

Diagnostic performance of the Sofia® influenza A+B fluorescent immunoassay in adult outpatients in Northern Taiwan

To evaluate the diagnostic performance of the Sofia influenza A+B fluorescent immunoassay (Sofia FIA), we performed a prospective study at the Chang Gung Memorial Hospital in Taiwan from January 2012 to December 2013. Patients who presented at out-patient clinics or the emergency department with influenza-like illness were included. Upper respiratory tract specimens were collected from oropharynx or nasopharynx. Performance of the Sofia FIA was compared to that of the Formosa One Sure Flu A/B Rapid Test. A Real-time reverse transcriptase-polymerase chain reaction assay (RT-PCR) and/or virus culture were used as reference standards. Of the 109 enrolled patients, the sensitivity, specificity, positive, and negative predictive values of the Sofia FIA to detect influenza A virus were 82%, 89%, 77%, and 89%, respectively. These parameters were 100% when the samples were from nasopharynx. The positive predictive value for influenza B virus detection was 29%. The sensitivity of the Sofia FIA for detection of influenza A virus was 93% between days 2 and 4 after onset of symptoms. For specimens with low viral loads (RT-PCR cycle threshold between 30 and 34.9), the sensitivity of The Sofia FIA was 83% (10/12). The Sofia FIA performed effectively in detecting influenza A virus infection. With nasopharyngeal samples, the performance was comparable to RT-PCR. Although influenza viral load typically decreases with time, the Sofia FIA was sensitive enough to identify influenza infecting patients presenting after several days of illness. However, a high false positive rate limits the assay's usefulness to identify influenza B virus infection.

Treatment outcome of non-carbapenemase-producing carbapenem-resistant Klebsiella pneumoniae infections: a multicenter study in Taiwan

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections are associated with high mortality, and experiences with its treatment are usually based on carbapenemase-producing strains. Non-carbapenemase-producing CRKP is of clinical significance, but relevant studies are lacking. This nationwide study aimed to evaluate the outcome of antimicrobial therapy in patients with non-carbapenemase-producing CRKP infections. Patients with non-carbapenemase-producing CRKP infections were enrolled from 16 hospitals during January 2013 to December 2014 in Taiwan. Carbapenem resistance was defined as reduced susceptibility with a minimum inhibitory concentration of ≥2 mg/L for imipenem or meropenem. The resistance mechanisms of CRKP isolates were analyzed, and the clinical data of these patients were collected retrospectively. Independent risk factors of 14-day morality were determined by Cox regression analysis. A total of 99 patients with non-carbapenemase-producing CRKP infections were enrolled, and 14-day mortality was 27.3%. Among 67 patients treated with appropriate antimicrobial therapy, most (n = 61) patients received monotherapy. The 14-day mortality was lower in patients treated with appropriate monotherapy (21.3%) than in those with inappropriate therapy (37.5%). The multivariate regression model identified monotherapy (hazard ratio [HR], 0.30; 95% confidence interval [CI], 0.13-0.71; P = 0.005) as protective factor, and APACHE II scores (HR, 1.09; 95% CI, 1.01-1.18; P = 0.022) as risk factor associated with 14-day mortality. Tigecycline, colistin, and carbapenem were the most commonly used drugs in monotherapy. This study provides evidence supporting the efficacy of monotherapy in the treatment of non-carbapenemase-producing CRKP infections, and provides a future target for antibiotics stewardship for CRKP infection.

Risk factors and outcomes of candidemia caused by Candida parapsilosis complex in a medical center in northern Taiwan

To investigate the risk factors and outcomes associated with Candida parapsilosis candidemia, a retrospective study was conducted at a tertiary medical center in northern Taiwan. Patients with C. parapsilosis candidemia and corresponding controls with C. albicans candidemia were chosen and their demographics, comorbidities, risk factors, and clinical outcomes were reviewed. Antifungal susceptibility tests were performed using the Sensititre YeastOne colorimetric system. Matrix-assisted laser desorption ionization-time of flight mass spectrometry was used to classify the genomic species. Of the 270 candidemias found in 253 patients, C. albicans was the most common Candida species isolated (43.0%), followed by C. parapsilosis (22.6%), C. tropicalis (17.4%), and C. glabrata (10.0%). The 30-day mortality of C. parapsilosis candidemia was significantly lower than that of C. albicans candidemia (21.7% vs. 53.9%, P<0.001). C. parapsilosis was positively associated with antifungal agent exposure [OR 7.261 (95% CI, 1.603-32.879), P=0.010], but negatively associated with Candida colonization [OR 0.303 (95% CI, 0.123-0.745), P=0.009], and immunosuppressant use [OR 0.264 (95% CI, 0.099-0.705), P=0.008]. In-hospital mortality was associated with the Sequential Organ Failure Assessment Score [OR 1.255 (95% CI, 1.002-1.573), P=0.048]. The clinical outcomes did not differ across genomic species and in the minimum inhibitory concentrations of fluconazole.

Clinical characteristics and treatment outcomes of vancomycin-resistant Enterococcus faecium bacteremia

BACKGROUND

Vancomycin-resistant Enterococcus faecium (VRE-fm) bacteremia causes significant mortality in hospitalized patients. We sought to investigate clinical characteristics, treatment outcomes, and microbiological eradication associated with VRE-fm bacteremia.

METHODS

A retrospective cohort study was conducted and included 210 adult patients admitted between January 1, 2011 and December 31, 2015.

RESULTS

The mean Pitt bacteremia score was 4.7. ICU stay (48.6%) and mechanical ventilation (46.2%) were common. Diabetes mellitus was the most common concomitant disease (43.3%), followed by malignancies, including hematologic malignancies (14.3%) and solid cancers (28.1%). The 14-day and 28-day mortality rates were 37.1% and 50.5%, respectively. Linezolid or daptomycin treatment for at least 10 days and higher Pitt bacteremia scores were independently associated with 14-day and 28-day mortality. Longer treatment duration of linezolid or daptomycin predicted microbiological eradication independently. Daptomycin-treated patients tended to have higher 14-day and 28-day mortality, and lower microbial eradication rates (20.8% versus 8.7%; 40.6% versus 26.1%; 14.1% versus 26.1%; respectively) than linezolid-treated patients, and cumulative survival rates at 14 and 28 days tended to be lower in patients who received low-dose daptomycin (<10 mg/kg/day) than that in those who received linezolid and high-dose daptomycin (≥10 mg/kg/day); however, the differences were not statistically significant.

CONCLUSION

Higher disease severity and inappropriate treatment were associated with increased mortality and longer treatment duration of linezolid or daptomycin was associated with microbial eradication for the patient with VRE-fm bacteremia.

Acquisition and clearance of multidrug resistant Acinetobacter baumannii on healthy young adults concurrently burned in a dust explosion in Taiwan: the implication for antimicrobial stewardship

Background

Information is limited about the effect of restricted carbapenem use on clearance of multi-drug resistant Acinetobacter baumannii (MDRAB). We sought to determine the time effect of antibiotic exposure on multi-drug resistant Acinetobacter baumannii (MDRAB) acquisition and clearance.

Methods

We conducted a retrospective observational study at the intensive care units of a tertiary medical center. Forty-two of a cohort of previously healthy young adults who were concurrently burned by a dust explosion was included. Cases consisted of those from whom MDRAB was isolated during hospitalization. Controls consisted of patients from whom MDRAB was not isolated in the same period. Use of antimicrobial agents was compared based on days of therapy per 1,000 patient-days (DOT/1,000PD). A 2-state Markov multi-state model was used to estimate the risk of acquisition and clearance of MDRAB.

Results

MDRAB was discovered in 9/42 (21.4%) individuals. The cases had significantly higher use of carbapenem (652 DOT/1,000PD vs. 385 DOT/1,000PD, P < 0.001) before MDRAB isolation. For the cases, clearance of MDRAB was associated with lower use of carbapenem (469 DOT/1,000PD vs. 708 DOT/1,000PD, P = 0.003) and higher use of non-carbapenem beta-lactam (612 DOT/1,000PD vs. 246 DOT/1,000PD, P <0.001). In multi-state model, each additional DOT of carbapenem increased the hazard of acquiring MDRAB (hazard ratio (HR), 1.08; 95% confidence interval (CI) 1.01–1.16) and each additional DOT of non-carbapenem beta-lactam increased the protection of clearing MDRAB (HR, 1.25; 95% CI 1.07–1.46).

Conclusions

Both acquisition and clearance of MDRAB were related to antibiotic exposure in a homogeneous population. Our findings suggest that early discontinuation of carbapenem could be an effective measure in antibiotic stewardship for the control of MDRAB spreading.

Influence of borderline cefepime MIC on the outcome of cefepime-susceptible Pseudomonas aeruginosa bacteremia treated with a maximal cefepime dose: a hospital-based retrospective study

BACKGROUND

We assessed the influence of current cefepime minimal inhibitory concentration (MIC) breakpoints and the maximal cefepime dose on treatment outcomes in patients with bacteremia caused by cefepime-susceptible Pseudomonas aeruginosa.

METHODS

Adult patients hospitalized between July 2010 and June 2014 with a positive blood culture for cefepime-susceptible P. aeruginosa and receipt of cefepime as the primary therapy throughout the course were reviewed. Cefepime Etest^® MICs and clinical outcomes for P. aeruginosa bacteremia were reviewed to identify the MIC breakpoint influencing treatment outcomes.

RESULTS

Of the 90 patients enrolled, 49 (54.4%) were male (mean age = 66.8 years). The mean Acute Physiology and Chronic Health Evaluation II score was 22.01. Sixty patients (66.7%) received a maximal cefepime dose, and the 30-day crude mortality rate was 36.7%. MIC₉₀ of cefepime for P. aeruginosa was 8 mg/L. The cumulative survival rate at 30 days revealed that a lower cefepime MIC (<4 mg/L) for P. aeruginosa was associated with a higher survival rate than a higher MIC (≥4 mg/L) (72.6% vs. 23.5%, p < 0.0001). A cefepime MIC of ≥4 mg/L and age were independent risk factors for mortality, whereas the maximal cefepime dose was the independent protective factor. The use of a maximal cefepime dose did not improve the outcomes of patients with P. aeruginosa bacteremia at a MIC of ≥4 mg/L.

CONCLUSIONS

A cefepime MIC of 4 mg/L may predict an unfavorable outcome among patients with serious infections caused by P. aeruginosa, even the MICs still within the CLSI susceptibility breakpoint.

Pre-existing matched antigen exacerbates the disease of influenza virus infection by attenuating antigen-specific T cell immunity

Influenza virus infection causes mild and self-limiting illness in most of the healthy individuals, but some healthy people develops complications as a result of the infection and suffers from severe disease and eventually dies. Here we report that pre-existing matched antigens attenuate antigen-specific immunity to the infection. High virus load and associated increase of pathogenic innate response in the lungs exacerbates the disease. The C3-HAHigh and C3-HALow transgenic mice are with inherent expression of Hemagglutinin (HA) antigen from PR8 strain of H1N1 influenza virus. Compared to wild type mice, these mice suffered from severe disease and higher mortality upon infection of wild type PR8 virus but not upon infection of reverse genetically raised PR8 virus with replaced HA from H3N2 influenza virus. Adoptively transferred PR8 virus HA-specific 6.5 CD4+ and Clone-4 CD8+ T cells responded minimally to PR8 virus infection in C3-HA mice. There was less clonotypic expansion, T-bet induction and effector cytokines IFN-γ and TNF-α production of both 6.5 CD4+ and Clone-4 CD8+ T cells. Virus neutralizing antibodies were less as well. The attenuation was associated with increased LAG-3+ but not Foxp-3+ population of HA-specific T cells in the lungs. In contrast to the instigated weak antigen-specific immunity, PR8 virus infection caused neutrophils more efficient for inflammatory IL-6 secretion and robust bronchus infiltration in C3-HA mice. These results suggest that a host factor cross-reactive to the antigens of influenza virus may exacerbate the disease with similar attenuated antigen-specific adaptive immunity accompanied by augmented innate immunity to influenza virus infection.

Neuraminidase-mediated TGF-β activation facilitates evolution of protective Th17 immunity

The immune system responds to influenza virus infection for eradication of the virus but the associated inflammation may cause tissue damage to the host. In our antigen-specific mouse system, naïve influenza hemagglutinin (HA)-specific CD4+ T cells adoptively transferred with infection respond with Th1 phenotype and produce IFN-γ. Some of them secrete IL-17 as well. Second batch HA specific CD4+ T cells, adoptively transferred on day 4 after infection and the first transfer, respond to the infection with Th17 phenotype. They produce IL-17 but not IFN-γ. Both the Th1 and Th17 cells are activated with similar levels of ZAP-70 phosphorylation and T-bet induction. For the Th17 cells, IFN-γ deficiency is associated with excessive ROR-γt induction and altered T-bet dominance. Th17 cells display surface LAG-3 expression, suppress T cell activation in vitro and decrease lung inflammation in vivo. The evolution of Th17 cells is augmented in IL-10 deficiency, with IL-10 knockout mice as the recipients transferred with IL-10 knockout HA specific CD4+ T cells. There is increased neuraminidase-mediated TGF-β activation in this IL-10 deficient environment. Viral neuraminidase mediated TGF-β activation in the first batch of HA specific CD4+ T cells facilitates the Th17 evolution of the 2nd batch of cells. The 6.5 T cell receptor (TCR) transgenic mice of monotonous HA specific TCR repertoire respond to influenza virus infection with Th17 deviation and demonstrate survival benefit. Consecutive waves of naïve HA specific T cells from the thymus in 6.5 mice may evolve with mechanisms similar to consecutive adoptive transfers. Evolution of protective Th17 immunity is facilitated by neuraminidase-mediated TGF-β activation.

[Application of standardization of medical care model for chronic mild lead poisoning]

OBJECTIVE

To standardize the treatment and evaluate the clinical application effectiveness of clinical pathway (CP) in chronic mild lead poisoning.

METHODS

60 patients with chronic mild lead poisoning hospitalized from Jan. 2014 to Dec.2014 were enrolled for the study group, 60 patients with chronic mild lead poisoning hospitalized from Jan.2013 to Dec.2013 were enrolled for the control group. The study group were cared according to clinical pathway, the control group received routine therapy; the clinical application effectiveness were compared between the two groups.

RESULTS

No adverse drug reactions occurred in both groups. The curative ratio was significantly higher in the study group than in the control group (96.7% vs 86.0%, P<0.05) , the rate of patients' satisfaction to medical care significantly higher in the study group (98.3% vs 88.3%, P<0.05) , the rate of health education awareness higher in the study group (95.0% vs 81.7%, P<0.05) , the course of treatment shorter in the study group (3.2±0.6 vs 3.4±0.7, P<0.05) , the medical cost less in the study group (5773.5 yuan±1242.1 yuan vs 6354.7 yuan±1177.0 yuan, P<0.05) , the length of hospitalization was shorter in the study group (21.9 d±6.7 d vs 24.6 d±7.9 d, P<0.05). The variation rate of clinical pathway was 13.3% in clinical pathway group.

CONCLUSION

The implementation of clinical pathway could improve the curative ratio, satisfaction, and health education awareness. The course of treatment, length of hospital stay and costs of hospitalization in the study group could be obviously shorter and less, and there is a little variation rate in the clinical pathway.

Impact of pneumococcal conjugate vaccine in children on the serotypic epidemiology of adult invasive pneumococcal diseases in Taiwan

BACKGROUND

Invasive pneumococcal disease (IPD) causes significant morbidity and mortality, especially in children and older adults. Pneumococcal 7-valent and 13-valent conjugate vaccines (PCV7 and PCV13) were introduced in Taiwan in 2005 and 2011, respectively, for children. This study was conducted to evaluate the impact of PCV administered in children on adult IPD.

METHODS

From the logbooks of microbiology laboratories, we retrospectively retrieved Streptococcus pneumoniae isolates, collected from normally sterile sites in adult patients. One hundred and fifty-seven consecutive, nonduplicated isolates were collected from one hospital during 2001 and 2003 (pre-PCV period) and 150 isolates from three hospitals from July 2011 to June 2015 (post-PCV period). Serotypes were determined by Quellung test.

RESULTS

Among the 307 isolates, 31 serotypes/serogroups were identified. PCV7 serotypes, particularly types 14 (31.2%), 23F (19.7%) and 6B (12.7%) dominated in the pre-PCV period (78.3%) but significantly decreased in the post-PCV period (36%) (p < 0.01). PCV13 specific serotypes (PCV13-PCV7) significantly increased from 7% of the isolates in the pre-PCV period to 28.7% of the isolates in the post-PCV period (p < 0.001), particularly type 19A (from 0.6% to 10%) and 6A (from 0 to 6.7%). Serotype 15B also increased significantly from 0.6% to 6.7% (p < 0.01). Nonvaccine serotypes increased significantly in the post-PCV period (11.5% to 22.0%, p < 0.05), particularly type 15A (from 0 to 4.4%, p < 0.01).

CONCLUSION

Serotype distribution of adult IPD in Taiwan has evolved after the introduction of PCV in children, indicating an indirect impact in adults. Continuous surveillance after the PCV13 vaccination program in children is needed.