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In subjects with peculiar susceptibility to severe infections by common pyogenic bacteria, mutations of interleukin-1 receptor-associated kinase proteins (IRAK)1 and IRAK4 had been identified. The IRAK kinases function as downstream signal transductors following the activation of pathogen recognition receptors. In two patients with sequential or repeated invasive infections: herpes simplex virus-triggered hemophagocytic lymphohistiocytosis with tuberculosis, and Streptococcus pneumoniae bacteremia with candidemia respectively, novel mutations of IRAK2 were identified. These mutations compromised the capacity to ubiquinate (or functionally modify) the signal adaptor tumor necrosis factor receptor-associated factor 6. The result is impairment of the cytokine tumor necrosis factor-alpha production. This susceptibility to a varied range of pathogens underlines a potential central role played by IRAK2 in mediating host defense in infectious diseases., Competing Interests: Declarations of competing interest The authors have no competing interests to declare., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

T cell acute lymphoblastic leukemia (T-ALL) is difficult to treat when it relapses after therapy or is chemoresistant; the prognosis of patients with relapsed or refractory T-ALL is generally poor. We report a case series of 17 such patients who received autologous chimeric antigen receptor (CAR) T cells expressing an anti-CD7 CAR and an anti-CD7 protein expression blocker (PEBL), which prevented CAR T cell fratricide. Despite high leukemic burden and low CAR T cell dosing, 16 of the 17 patients attained minimal residual disease-negative complete remission within 1 month. The remaining patient had CD7 - T-ALL cells before infusion, which persisted after infusion. Toxicities were mild: cytokine release syndrome grade 1 in ten patients and grade 2 in three patients; immune effector cell-associated neurotoxicity syndrome grade 1 in two patients. Eleven patients remained relapse-free (median follow-up, 15 months), including all nine patients who received an allotransplant. The first patient is in remission 55 months after infusion without further chemotherapy or transplantation; circulating CAR T cells were detectable for 2 years. T cells regenerating after lymphodepletion lacked CD7 expression, were polyclonal and responded to SARS-CoV-2 vaccination; CD7 + immune cells reemerged concomitantly with CAR T cell disappearance. In conclusion, autologous anti-CD7 PEBL-CAR T cells have powerful antileukemic activity and are potentially an effective option for the treatment of T-ALL., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Objectives: To investigate multi-dose and timings of COVID-19 vaccines in preventing antenatal infection., Design: Prospective observational study investigating primary vaccinations, boosters, antenatal COVID-19 infections, neutralizing antibody (Nab) durability, and cross-reactivity to Delta and Omicron variants of concern (VOCs)., Results: Ninety-eight patients completed primary vaccination prepregnancy (29.6%) and antenatally (63.3%), 24.2% of whom had antenatal COVID-19, while 7.1% were unvaccinated (28.6% had antenatal COVID-19). None had severe COVID-19. Prepregnancy vaccination resulted in vaccination-to-infection delay of 23.3 weeks, which extended to 45.2 weeks with a booster, compared to 16.9 weeks following antenatal vaccination (P < 0.001). Infections occurred at 26.2 weeks gestation in women vaccinated prepregnancy compared to 36.2 weeks gestation in those vaccinated during pregnancy (P < 0.007). The risk of COVID-19 infection was higher without antenatal vaccination (hazard ratio [HR] 14.6, P = 0.05) and after prepregnancy vaccination without a booster (HR 10.4, P = 0.002). Antenatal vaccinations initially led to high Nab levels, with mild waning but subsequent rebound. Significant Nab enhancement occurred with a third-trimester booster. Maternal-neonatal Nab transfer was efficient (transfer ratio >1), and cross-reactivity to VOCs was observed., Conclusion: Completing vaccination during any trimester delays COVID-19 infection and maintains effective neutralizing activity throughout pregnancy, with robust cross-reactivity to VOCs and efficient maternal-neonatal transfer., Competing Interests: Declarations of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Molecular chaperons stabilize protein folding and play a vital role in maintaining tissue homeostasis. To this intent, mitochondrial molecular chaperons may be involved in the regulation of oxidative phosphorylation and apoptosis during stress events such as infections. However, specific human infectious diseases relatable to defects in molecular chaperons have yet to be identified. To this end, we performed whole exome sequencing and functional immune assessment in a previously healthy Asian female, who experienced severe respiratory failure due to Pneumocystis jiroveci pneumonia and non-HIV-related CD4 lymphocytopenia. This revealed that a chaperon, the mitochondrial paralog of HSP90, TRAP1, may have been involved in the patient's susceptibility to an opportunistic infection. Two rare heterozygous variants in TRAP1, E93Q, and A64T were detected. The patient's peripheral blood mononuclear cells displayed diminished TRAP1 expression, but had increased active, cleaved caspase-3, caspase-7, and elevated IL-1β production. Transfection of A64T and E93Q variants in cell lines yielded decreased TRAP1 compared to transfected wildtype TRAP1 and re-capitulated the immunotypic phenotype of enhanced caspase-3 and caspase-7 activity. When infected with live P. jiroveci , the E93Q or A64T TRAP1 mutant expressing cells also exhibited reduced viability. Patient cells and cell lines transfected with the TRAP1 E93Q/A64T mutants had impaired respiration, glycolysis, and increased ROS production. Of note, co-expression of E93Q/A64T double mutants caused more functional aberration than either mutant singly. Taken together, our study uncovered a previously unrecognized role of TRAP1 in CD4 + lymphocytopenia, conferring susceptibility to opportunistic infections., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Amali, Paramasivam, Huang, Joshi, Hirpara, Ravikumar, Sam, Tan, Tan, Kumar, Neckers, Pervaiz, Foo, Chan, Zhu, Lee and Chai.)

The 'rule-of-6' prediction tool was shown to be able to identify COVID-19 patients at risk of adverse outcomes. During the pandemic, we frequently observed hyponatremia at presentation. We sought to evaluate if adding hyponatremia at presentation could improve the 'rule-of-6' prediction tool. We retrospectively analysed 1781 consecutive patients admitted to a single tertiary academic institution in Singapore with COVID-19 infection from February 2020 to October 2021. A total of 161 (9.0%) patients had hyponatremia. These patients were significantly older, with more co-morbidities and more likely to be admitted during the Delta wave (2021). They were more likely to have radiographic evidence of pneumonia (46.0% versus 13.0%, p < 0.001) and more adverse outcomes (25.5% vs. 4.1%, p < 0.001). Hyponatremia remained independently associated with adverse outcomes after adjusting for age, lack of medical co-morbidities, vaccination status, year of admission, CRP, LDH, and ferritin. The optimised cut-off for serum sodium in predicting adverse outcomes was approximately <135 mmol/L as determined by the Youden index. Although derived in early 2020, the 'rule-of-6' prediction tool continued to perform well in our later cohort (AUC: 0.72, 95%CI: 0.66-0.78). Adding hyponatremia to the 'rule-of-6' improved its performance (AUC: 0.76, 95%CI: 0.71-0.82). Patients with hyponatremia at presentation for COVID-19 had poorer outcomes even as new variants emerged.

We describe bedside-to-bench immunological and genetic elucidation of defective pyroptosis attributable to novel caspase 4 defect mediating pathogen-triggered inflammatory programmed cell death, in the setting of severe pneumonia and abscess-forming melioidosis in an overtly healthy host failing to clear Burkholderia pseudomallei infection, and how targeted adjunctive biological therapy led to a successful outcome., Competing Interests: Potential conflicts of interest. G. M. reports an unpaid role as President of the Extracorporeal Life Support Organization (ELSO). All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Due to the paucity of longitudinal molecular studies of COVID-19, particularly those covering the early stages of infection (Days 1-8 symptom onset), our understanding of host response over the disease course is limited. We perform longitudinal single cell RNA-seq on 286 blood samples from 108 age- and sex-matched COVID-19 patients, including 73 with early samples. We examine discrete cell subtypes and continuous cell states longitudinally, and we identify upregulation of type I IFN-stimulated genes (ISGs) as the predominant early signature of subsequent worsening of symptoms, which we validate in an independent cohort and corroborate by plasma markers. However, ISG expression is dynamic in progressors, spiking early and then rapidly receding to the level of severity-matched non-progressors. In contrast, cross-sectional analysis shows that ISG expression is deficient and IFN suppressors such as SOCS3 are upregulated in severe and critical COVID-19. We validate the latter in four independent cohorts, and SOCS3 inhibition reduces SARS-CoV-2 replication in vitro. In summary, we identify complexity in type I IFN response to COVID-19, as well as a potential avenue for host-directed therapy., (© 2024. The Author(s).)

Importance: Despite patients with cancer being at risk of poor outcomes from COVID-19, there are few published studies for vaccine efficacy in this group, with suboptimal immunogenicity and waning vaccine efficacy described in small studies being a concern., Objective: To assess the incidence rate of severe COVID-19 disease outcomes associated with the number of vaccine doses received and the waning of protection over time., Design, Setting, and Participants: A prospective multicenter observational cohort study was carried out over 2 time periods (September 15, 2021, to December 20, 2021 [delta wave], and January 20, 2022, to November 11, 2022 [omicron wave]) predominated by SARS-CoV-2 delta and omicron variants, respectively. Overall, 73 608 patients with cancer (23 217 active treatment, 50 391 cancer survivors) and 621 475 controls matched by age, sex, race and ethnicity, and socioeconomic status were included., Exposure: Vaccine doses received, from zero to 4 doses, and time elapsed since last vaccine dose., Outcomes: Competing-risk regression analyses were employed to account for competing risks of death in patients with cancer. Main outcomes were incidence rate ratios (IRRs) of COVID-19 infection, hospitalization, and severe disease (defined as requirement for supplemental oxygen, intensive care, or death). The IRRs stratified by time from last vaccine dose served as indicators of waning of vaccine effectiveness over time., Results: The mean (SD) age of actively treated patients with cancer, cancer survivors, and controls were 62.7 (14.7), 62.9 (12.6), and 61.8 (14.7) years, respectively. Of 73 608 patients with cancer, 27 170 (36.9%) were men; 60 100 (81.6%) were Chinese, 7432 (10.1%) Malay, 4597 (6.2%) Indian, and 1479 (2.0%) were of other races and ethnicities. The IRRs for the 3-dose and 4-dose vs the 2-dose group (reference) for COVID-19 hospitalization and severe disease were significantly lower during both the delta and omicron waves in cancer and control populations. The IRRs for severe disease in the 3-dose group for active treatment, cancer survivors, and controls were 0.14, 0.13, and 0.07 during the delta wave and 0.29, 0.19, and 0.21 during omicron wave, respectively. The IRRs for severe disease in the 4-dose group during the omicron wave were even lower at 0.13, 0.10 and 0.10, respectively. No waning of vaccine effectiveness against hospitalization and severe disease was seen beyond 5 months after a third dose, nor up to 5 months (the end of this study's follow-up) after a fourth dose., Conclusion: This cohort study provides evidence of the clinical effectiveness of mRNA-based vaccines against COVID-19 in patients with cancer. Longevity of immunity in preventing severe COVID-19 outcomes in actively treated patients with cancer, cancer survivors, and matched controls was observed at least 5 months after the third or fourth dose.

Introduction: Invasive fungal infections (IFIs) in Asia/Pacific are a particular threat to patients with malignancies, uncontrolled diabetes mellitus or undiagnosed/untreated human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS). Adequate and early access to diagnostic tools and antifungals is essential for IFI clinical management and patient survival., Methods: Details on institution profile, self-perception on IFI, and access to microscopy, culture, serology, antigen detection, molecular testing, and therapeutic drug monitoring for IFI were collected in a survey., Results: As of June 2022, 235 centres from 40 countries/territories in Asia/Pacific answered the questionnaire. More than half the centres were from six countries: India (25%), China (17%), Thailand (5%), Indonesia, Iran, and Japan (4% each). Candida spp. (93%) and Aspergillus spp. (75%) were considered the most relevant pathogens. Most institutions had access to microscopy (98%) or culture-based approaches (97%). Furthermore, 79% of centres had access to antigen detection, 66% to molecular assays, and 63% to antibody tests. Access to antifungals varied between countries/territories. At least one triazole was available in 93% of the reporting sites (voriconazole [89%] was the most common mould-active azole), whereas 80% had at least one amphotericin B formulation, and 72% had at least one echinocandin., Conclusion: According to the replies provided, the resources available for IFI diagnosis and management vary among Asia/Pacific countries/territories. Economical or geographical factors may play a key role in the incidence and clinical handling of this disease burden. Regional cooperation may be a good strategy to overcome shortcomings., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Candida albicans is an opportunistic pathogen, with its infection as one of the causes of morbidity or mortality. Notably, the probiotic yeast Saccharomyces cerevisiae var. boulardii has shown the potential to fight against Candida infections. In this study, we aimed to engineer a commercial boulardii strain to produce medium-chain fatty acids (MCFAs) with antagonistic effects against C. albicans . First, we identified and characterized a boulardii strain and created its auxotrophic strain Δura3 . Next, we constructed and expressed a heterologous MCFA biosynthetic pathway under the control of inducible and constitutive promoters. Aside from examining MCFA production and secretion, we confirmed MCFAs' effects on C. albicans' anti-biofilm and anti-hyphal formations and the immunomodulatory effect of MCFA-containing supernatants on Caco-2 cells. We found that under constitutive promoters, the engineered boulardii strain constitutively produced and secreted a mixture of C6:0, C8:0, and C10:0. The secreted MCFAs then reduced biofilm and hyphal formations in C. albicans SC5314. We also confirmed that MCFAs upregulated the expression of virulence-related genes in SC5314. Furthermore, we found that the constitutively produced MCFAs in the supernatant induced the upregulation of immune response genes in Caco-2 cells co-cultured with SC5314, indicating MCFAs' roles in immunomodulation. Overall, the engineered boulardii strain produced and secreted MCFAs, as well as demonstrated antagonistic effects against C. albicans SC5314 and immune-modulatory effects in Caco-2. To our knowledge, this represents the first study tackling the metabolic engineering of a commercial probiotic yeast strain to constitutively produce and secrete MCFAs showing anti- Candida effects. Our study forms the basis of the potential development of a live biotherapeutics probiotic yeast against Candida infections through metabolic engineering strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Ling, Liu, Sam, Shen, Chai and Chang.)

The ideal strategy to fight an infection involves both (i) weakening the invading pathogen through conventional antimicrobial therapy, and (ii) strengthening defense through the augmentation of host immunity. This is even more pertinent in the context of invasive fungal infections whereby the majority of patients have altered immunity and are unable to mount an appropriate host response against the pathogen. Natural killer (NK) cells fit the requirement of an efficient, innate executioner of both tumour cells and pathogens - their unique, targeted cell killing mechanism, combined with other arms of the immune system, make them potent effectors. These characteristics, together with their ready availability (given the various sources of extrinsic NK cells available for harvesting), make NK cells an attractive choice as adoptive cellular therapy against fungi in invasive infections. Improved techniques in ex vivo NK cell activation with expansion, and more importantly, recent advances in genetic engineering including state-of-the-art chimeric antigen receptor platform development, have presented an opportune moment to harness this novel therapeutic as a key component of a multipronged strategy against invasive fungal infections., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Oh, Chan and Chai.)

Introduction: Three doses of SARS-CoV-2 mRNA vaccines have been recommended for cancer patients to reduce the risk of severe disease. Anti-neoplastic treatment, such as chemotherapy, may affect long-term vaccine immunogenicity., Method: Patients with solid or haematological cancer were recruited from 2 hospitals between July 2021 and March 2022. Humoral response was evaluated using GenScript cPASS surrogate virus neutralisation assays. Clinical outcomes were obtained from medical records and national mandatory-reporting databases., Results: A total of 273 patients were recruited, with 40 having haematological malignancies and the rest solid tumours. Among the participants, 204 (74.7%) were receiving active cancer therapy, including 98 (35.9%) undergoing systemic chemotherapy and the rest targeted therapy or immunotherapy. All patients were seronegative at baseline. Seroconversion rates after receiving 1, 2 and 3 doses of SARS-CoV-2 mRNA vaccination were 35.2%, 79.4% and 92.4%, respectively. After 3 doses, patients on active treatment for haematological malignancies had lower antibodies (57.3%±46.2) when compared to patients on immunotherapy (94.1%±9.56, P <0.05) and chemotherapy (92.8%±18.1, P <0.05). SARS-CoV-2 infection was reported in 77 (28.2%) patients, of which 18 were severe. No patient receiving a third dose within 90 days of the second dose experienced severe infection., Conclusion: This study demonstrates the benefit of early administration of the third dose among cancer patients.

Human cells homozygous for rare loss-of-expression (LOE) TYK2 alleles have impaired, but not abolished, cellular responses to IFN-α/β (underlying viral diseases in the patients) and to IL-12 and IL-23 (underlying mycobacterial diseases). Cells homozygous for the common P1104A TYK2 allele have selectively impaired responses to IL-23 (underlying isolated mycobacterial disease). We report three new forms of TYK2 deficiency in six patients from five families homozygous for rare TYK2 alleles (R864C, G996R, G634E, or G1010D) or compound heterozygous for P1104A and a rare allele (A928V). All these missense alleles encode detectable proteins. The R864C and G1010D alleles are hypomorphic and loss-of-function (LOF), respectively, across signaling pathways. By contrast, hypomorphic G996R, G634E, and A928V mutations selectively impair responses to IL-23, like P1104A. Impairment of the IL-23-dependent induction of IFN-γ is the only mechanism of mycobacterial disease common to patients with complete TYK2 deficiency with or without TYK2 expression, partial TYK2 deficiency across signaling pathways, or rare or common partial TYK2 deficiency specific for IL-23 signaling., (© 2022 Ogishi et al.)

Nanomedicine-based and unmodified drug interventions to address COVID-19 have evolved over the course of the pandemic as more information is gleaned and virus variants continue to emerge. For example, some early therapies (e.g., antibodies) have experienced markedly decreased efficacy. Due to a growing concern of future drug resistant variants, current drug development strategies are seeking to find effective drug combinations. In this study, we used IDentif.AI, an artificial intelligence-derived platform, to investigate the drug-drug and drug-dose interaction space of six promising experimental or currently deployed therapies at various concentrations: EIDD-1931, YH-53, nirmatrelvir, AT-511, favipiravir, and auranofin. The drugs were tested in vitro against a live B.1.1.529 (Omicron) virus first in monotherapy and then in 50 strategic combinations designed to interrogate the interaction space of 729 possible combinations. Key findings and interactions were then further explored and validated in an additional experimental round using an expanded concentration range. Overall, we found that few of the tested drugs showed moderate efficacy as monotherapies in the actionable concentration range, but combinatorial drug testing revealed significant dose-dependent drug-drug interactions, specifically between EIDD-1931 and YH-53, as well as nirmatrelvir and YH-53. Checkerboard validation analysis confirmed these synergistic interactions and also identified an interaction between EIDD-1931 and favipiravir in an expanded range. Based on the platform nature of IDentif.AI, these findings may support further explorations of the dose-dependent drug interactions between different drug classes in further pre-clinical and clinical trials as possible combinatorial therapies consisting of unmodified and nanomedicine-enabled drugs, to combat current and future COVID-19 strains and other emerging pathogens.

Importance: Patients with cancer have an increased risk of severe disease and mortality from COVID-19, as the disease and antineoplastic therapy cause reduced vaccine immunogenicity. Booster doses have been proposed to enhance protection, and efficacy data are emerging from several studies., Objective: To evaluate the proportion of COVID-19 primary vaccination non-responders with cancer who seroconvert after a booster dose., Methods: PubMed, EMBASE, CENTRAL and medRxiv were searched from 1st January 2021 to 10th March 2022. Quality was assessed using the Joanna Briggs Institute Critical Appraisal checklist., Results: After the eligibility assessment, 22 studies were included in this systematic review and 17 for meta-analysis of seroconversion in non-responders, pooling a total of 849 patients with haematological cancer and 82 patients with solid cancer. Haematological cancer non-responders exhibited lower seroconversion at 44% (95% CI 36-53%) than solid cancer at 80% (95% CI 69-87%). Individual patient data meta-analysis found the odds of having a meaningful rise in antibody titres to be significantly associated with increased duration between the second and third dose (OR 1.02, 95% CI 1.00-1.03, P ≤ 0.05), age of patient (OR 0.960, 95% CI 0.934-0.987, P ≤ 0.05) and cancer type. With patients with haematological cancer as a reference, patients with lung cancer had 16.8 times the odds of achieving a meaningful increase in antibody titres (OR 16.8, 95% CI 2.95-318, P ≤ 0.05) and gastrointestinal cancer patients had 25.4 times the odds of achieving a meaningful increase in antibody titres (OR 25.4, 95% CI 5.26-492.21, P ≤ 0.05)., Conclusions: administration of a COVID-19 vaccine booster dose is effective in improving seroconversion and antibody levels. Patients with haematological cancer consistently demonstrate poorer response to booster vaccines than patients with solid cancer., Competing Interests: Conflict of interest statement The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: YYS—honoraria (AstraZeneca); RS—honoraria (MSD, Eli Lilly, BMS, Roche, Taiho, Astra Zeneca, DKSH), consulting or advisory role (Bristol Myers Squibb, Merck, Eisai, Bayer, Taiho, Novartis, MSD, GSK), research funding (Paxman Coolers, MSD), travel (Roche, Astra Zeneca, Taiho, Eisai, DKSH). DB—Sana Biotechnology has licensed intellectual property of DB and Washington University in St. Louis. Gilead Biosciences has licensed intellectual property of D.B. and Stanford University. DB is a co-founder of Clade Therapeutics. DB serves on a COVID-19 therapeutics advisory panel for GlaxoSmithKline. BJL—has a financial interest in Cofactor Genomics, Inc. and Iron Horse Dx. RTS—receives research funding from Merck, Rafael Pharmaceuticals, ImmunoVaccine, Bayer, SeaGen, Exelixis, Pieris, LOXO Oncology, Novocure, NuCana, QED and has served as a consultant/advisor to Merck, Servier, Astra-Zeneca, EMD Serono, Taiho, QED, Incyte, Genentech, Basilea. YH—Honoraria from ABBVIE, Janssen, Astra-Zeneca, Roche and Medison, all outside of the submitted work. All other authors have no conflicts of interest to declare., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Resistance to azoles in Candida tropicalis is increasing and may be mediated by genetic characteristics. Using whole genome sequencing (WGS), we examined the genetic diversity of 82 bloodstream C. tropicalis isolates from two countries and one ATCC strain in a global context. Multilocus sequence typing (MLST) and single nucleotide polymorphism (SNP)-based phylogenies were generated. Minimum inhibitory concentrations (MIC) for antifungal agents were determined using Sensititre YeastOne YO10. Eleven (13.2%) isolates were fluconazole-resistant and 17 (20.5%) were classified as fluconazole-non susceptible (FNS). Together with four Canadian isolates, the genomes of 12 fluconazole-resistant (18 FNS) and 69 fluconazole-susceptible strains were examined for gene mutations associated with drug resistance. Fluconazole-resistant isolates contained a mean of 56 non-synonymous SNPs per isolate in contrast to 36 SNPs in fluconazole-susceptible isolates (interquartile range [IQR] 46−59 vs. 31−48 respectively; p < 0.001). Ten of 18 FNS isolates contained missense ERG11 mutations (amino acid substitutions S154F, Y132F, Y257H). Two echinocandin-non susceptible isolates had homozygous FKS1 mutations (S30P). MLST identified high genetic diversity with 61 diploid sequence types (DSTs), including 53 new DSTs. All four isolates in DST 773 were fluconazole-resistant within clonal complex 2. WGS showed high genetic variation in invasive C. tropicalis; azole resistance was distributed across different lineages but with DST 773 associated with in vitro fluconazole resistance., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Host factors leading to pulmonary nontuberculous mycobacteria (PNTM) disease are poorly understood compared with disseminated NTM disease, which is linked to the interleukin 12-interferon gamma signaling pathway. We investigated the tumor necrosis factor receptor associated factor 3 (TRAF3) R338W variant in a patient with recurrent PNTM infection, demonstrating TRAF3- and TNF-α-deficient phenotypes via ex vivo immune and cloning-transfection cellular studies., (© The Author(s) 2022. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

IDentif.AI-x, a clinically actionable artificial intelligence platform, was used to rapidly pinpoint and prioritize optimal combination therapies against COVID-19 by pairing a prospective, experimental validation of multi-drug efficacy on a SARS-CoV-2 live virus and Vero E6 assay with a quadratic optimization workflow. A starting pool of 12 candidate drugs developed in collaboration with a community of infectious disease clinicians was first narrowed down to a six-drug pool and then interrogated in 50 combination regimens at three dosing levels per drug, representing 729 possible combinations. IDentif.AI-x revealed EIDD-1931 to be a strong candidate upon which multiple drug combinations can be derived, and pinpointed a number of clinically actionable drug interactions, which were further reconfirmed in SARS-CoV-2 variants B.1.351 (Beta) and B.1.617.2 (Delta). IDentif.AI-x prioritized promising drug combinations for clinical translation and can be immediately adjusted and re-executed with a new pool of promising therapies in an actionable path towards rapidly optimizing combination therapy following pandemic emergence., (© 2022. The Author(s).)

Objectives: Highly effective vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed but variants of concerns are worrisome, especially B.1.617.2 (Delta) which has rapidly spread across the world. We aim to study if vaccination alters virological and serological kinetics in breakthrough infections., Methods: We conducted a multicentre retrospective cohort study of patients in Singapore who had received a licensed mRNA vaccine and been admitted to hospital with B.1.617.2 SARS-CoV-2 infection. We compared clinical features, virological and serological kinetics (anti-nucleocapsid, anti-spike and surrogate virus neutralization titres) between fully vaccinated and unvaccinated individuals., Results: Out of 218 individuals with B.1.617.2 infection, 84 received an mRNA vaccine of which 71 were fully vaccinated, 130 were unvaccinated and four received a non-mRNA vaccine. Despite significantly older age in the vaccine breakthrough group, only 2.8% (2/71) developed severe COVID-19 requiring oxygen supplementation compared with 53.1% (69/130) in the unvaccinated group (p < 0.001). Odds of severe COVID-19 following vaccination were significantly lower (adjusted odds ratio 0.07 95% CI 0.015-0.335, p 0.001). PCR cycle threshold values were similar between vaccinated and unvaccinated groups at diagnosis, but viral loads decreased faster in vaccinated individuals. Early, robust boosting of anti-spike protein antibodies was observed in vaccinated patients; however, these titres were significantly lower against B.1.617.2 than the wildtype vaccine strain., Discussion: The mRNA vaccines are highly effective at preventing symptomatic and severe COVID-19 associated with B.1.617.2 infection. Vaccination is associated with faster decline in viral RNA load and a robust serological response. Vaccination remains a key strategy for control of the COVID-19 pandemic., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Key knowledge gaps remain in the understanding of viral dynamics and immune response of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection., Methods: We evaluated these characteristics and established their association with clinical severity in a prospective observational cohort study of 100 patients with PCR-confirmed SARS-CoV-2 infection (mean age, 46 years; 56% male; 38% with comorbidities). Respiratory samples (n = 74) were collected for viral culture, serum samples for measurement of IgM/IgG levels (n = 30), and plasma samples for levels of inflammatory cytokines and chemokines (n = 81). Disease severity was correlated with results from viral culture, serologic testing, and immune markers., Results: Fifty-seven (57%) patients developed viral pneumonia, of whom 20 (20%) required supplemental oxygen, including 12 (12%) with invasive mechanical ventilation. Viral culture from respiratory samples was positive for 19 of 74 patients (26%). No virus was isolated when the PCR cycle threshold (Ct) value was >30 or >14 days after symptom onset. Seroconversion occurred at a median (IQR) of 12.5 (9-18) days for IgM and 15.0 (12-20) days for IgG; 54/62 patients (87.1%) sampled at day 14 or later seroconverted. Severe infections were associated with earlier seroconversion and higher peak IgM and IgG levels. Levels of IP-10, HGF, IL-6, MCP-1, MIP-1α, IL-12p70, IL-18, VEGF-A, PDGF-BB, and IL-1RA significantly correlated with disease severity., Conclusions: We found virus viability was associated with lower PCR Ct value in early illness. A stronger antibody response was associated with disease severity. The overactive proinflammatory immune signatures offer targets for host-directed immunotherapy, which should be evaluated in randomized controlled trials., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Diagnostic tests for fungi provide the mycological evidence to strengthen diagnosis of invasive fungal disease. Conventional microbiology and histopathology have their limitations. Recognizing this, there have been attempts at developing new methods to improve yield of diagnosing invasive fungal disease (IFD). The recent focus has been on non-culture-based antigen detection and molecular methods. The use of antigen detection of IFD through 1,3-β-D-glucan and galactomannan assay have been expanded, followed by development of lateral flow assays, and in combination with other diagnostic modalities to further increase diagnostic yield. The molecular diagnostic front has seen initiatives to standardize polymerase chain reaction methodologies to detect fungi and anti-fungal resistance, new platforms such as the T2Candida Biosystems and foray into fungal metagenomics. As these newer assays undergo stringent validation before incorporation into the diagnostic algorithm, the clinician needs to be mindful of their bedside utility as well as their limitation., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

The existence of a hyperinflammatory state has been observed in patients with invasive fungal infections (IFI). It is being postulated whether morbidity from IFI may, in part, be a consequence of an unnecessarily prolonged or exaggerated proinflammatory immune response including interleukin 6 (IL-6) post-infection, in a host with dysregulated or compromised immunity. This, in turn, induces collateral host injury at the tissue and organ level, leading to adverse outcomes. Tocilizumab has become widely used as an immunomodulator in the treatment of inflammatory conditions. Here, we evaluated the use of tocilizumab to curb post-infective inflammatory flare in the setting of an in-vivo mouse model for invasive candidiasis. Following Candida infection, the tocilizumab-treated mice showed improved short-term survival compared with the saline-treated control mice. There was a reduced inflammatory response mounted by the host, coupled with reduced IL-6 but increased IL-10 levels. TNF-α and IFN-γ responses were not affected. Tocilizumab facilitated immune tolerance by selectively inducing IL-10, producing CD8α+ conventional dendritic cells (DCs) and peripheral T-regulatory cells, over CD11b+ conventional DCs and plasmacytoid DCs. We demonstrate here the sequelae from immunomodulatory manipulation and the basis whereby the use of monoclonal antibodies may be further explored in IFI.

Fatty acids are derived from diet and fermentative processes by the intestinal flora. Two to five carbon chain fatty acids, termed short chain fatty acids (SCFA) are increasingly recognized to play a role in intestinal homeostasis. However, the characteristics of slightly longer 6 to 10 carbon, medium chain fatty acids (MCFA), derived primarily from diet, are less understood. Here, we demonstrated that SCFA and MCFA have divergent immunomodulatory propensities. SCFA down-attenuated host pro-inflammatory IL-1β, IL-6, and TNFα response predominantly through the TLR4 pathway, whereas MCFA augmented inflammation through TLR2. Butyric (C4) and decanoic (C10) acid displayed most potent modulatory effects within the SCFA and MCFA, respectively. Reduction in TRAF3, IRF3 and TRAF6 expression were observed with butyric acid. Decanoic acid induced up-regulation of GPR84 and PPARγ and altered HIF-1α/HIF-2α ratio. These variant immune characteristics of the fatty acids which differ by just several carbon atoms may be attributable to their origins, with SCFA being primarily endogenous and playing a physiological role, and MCFA exogenously from the diet.

Serial galactomannan (GM) monitoring can aid the diagnosis of invasive aspergillosis (IA) and optimise treatment decisions. However, widespread adoption of mould-active prophylaxis has reduced the incidence of IA and challenged its use. We evaluated the cost-effectiveness of prophylaxis-biomarker strategies. A Markov model simulating high-risk patients undergoing routine GM surveillance with mould-active versus non-mould-active prophylaxis was constructed. The incremental cost for each additional quality-adjusted life-year (QALY) gained over a lifetime horizon was calculated. In 40- and 60-year-old patients receiving mould-active prophylaxis coupled with routine GM surveillance, the total cost accrued was the lowest at SGD 11,227 (USD 8255) and SGD 9234 (USD 6790), respectively, along with higher QALYs gained (5.3272 and 1.1693). This strategy, being less costly and more effective, dominated mould-active prophylaxis with no GM monitoring or GM surveillance during non-mould-active prophylaxis. The prescription of empiric antifungal treatment was influential in the cost-effectiveness. When the GM test sensitivity was reduced from 80% to 30%, as might be anticipated with the use of mould-active prophylactic agents, the conclusion remained unchanged. The likelihood of GM surveillance with concurrent mould-active prophylaxis being cost-effective was 77%. Routine GM surveillance remained cost-effective during mould-active prophylaxis despite lower IA breakthroughs. Cost-saving from reduced empirical antifungal treatment was an important contributing factor.

We aim to describe a case series of critically and non-critically ill COVID-19 patients in Singapore. This was a multicentered prospective study with clinical and laboratory details. Details for fifty uncomplicated COVID-19 patients and ten who required mechanical ventilation were collected. We compared clinical features between the groups, assessed predictors of intubation, and described ventilatory management in ICU patients. Ventilated patients were significantly older, reported more dyspnea, had elevated C-reactive protein and lactate dehydrogenase. A multivariable logistic regression model identified respiratory rate (aOR 2.83, 95% CI 1.24-6.47) and neutrophil count (aOR 2.39, 95% CI 1.34-4.26) on admission as independent predictors of intubation with area under receiver operating characteristic curve of 0.928 (95% CI 0.828-0.979). Median APACHE II score was 19 (IQR 17-22) and PaO2/FiO2 ratio before intubation was 104 (IQR 89-129). Median peak FiO2 was 0.75 (IQR 0.6-1.0), positive end-expiratory pressure 12 (IQR 10-14) and plateau pressure 22 (IQR 18-26) in the first 24 h of ventilation. Median duration of ventilation was 6.5 days (IQR 5.5-13). There were no fatalities. Most COVID-19 patients in Singapore who required mechanical ventilation because of ARDS were extubated with no mortality.

We report on 2 Asian siblings with X-linked inhibitor of apoptosis deficiency that arose from a novel deletion that presented with Epstein-Barr virus disease and hemophagocytic lymphohistiocytosis. This disease is ascribed to dysfunction in the nucleotide binding and oligomerization domain receptor pathway, tested using a modified muramyl dipeptide-mediated assay., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Journal of the Pediatric Infectious Diseases Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objectives: Nosocomial infection is an ongoing concern in the COVID-19 outbreak. The effective screening of suspected cases in the healthcare setting is therefore necessary, enabling the early identification and prompt isolation of cases for epidemic containment. We aimed to assess the cost and health outcomes of an extended screening strategy, implemented in Singapore on 07 February 2020, which maximizes case identification in the public healthcare system., Methods: We explored the effects of the expanded screening criteria which allow clinicians to isolate and investigate patients presenting with undifferentiated fever or respiratory symptoms or chest x-ray abnormalities. We formulated a cost appraisal framework which evaluated the treatment costs averted from the prevention of secondary transmission in the hospital setting, as determined by a branching process infection model, and compared these to the costs of the additional testing required to meet the criteria., Results: In the base case analysis, an R 0 of 2.5 and incubation period of 4 days, an estimated 239 (95% CI: 201-287) cases could be averted over 150 days within the hospital setting through ESC. A corresponding $2.36 (2-2.85) million USD in costs could be averted with net cost savings of $124,000 (95% CI: -334,000 to 516,000). In the sensitivity analyses, when positive identification rates (PIR) were above 7%, regardless of R 0 and incubation period, all scenarios were cost-saving., Conclusion: The expanded screening criteria can help to identify and promptly isolate positive COVID cases in a cost-saving manner or within acceptable cost margins where the costs incurred from the testing of negative patients could be negated by the averted costs. Outbreak control must be sustainable and effective; the proposed screening criteria should be considered to mitigate nosocomial transmission risk within healthcare facilities., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Invasive aspergillosis (IA) is a major opportunistic fungal infection in patients with haematological malignancies. Morbidity and mortality rates are high despite anti-fungal treatment, as the compromised status of immune system prevents the host from responding optimally to conventional therapy. This raises the consideration for immunotherapy as an adjunctive treatment. In this study, we evaluated the utility of expanded human NK cells as treatment against Aspergillus fumigatus infection in vitro and in vivo. The NK cells were expanded and activated by K562 cells genetically modified to express 4-1BB ligand and membrane-bound interleukin-15 (K562-41BBL-mbIL-15) as feeders. The efficacy of these cells was investigated in A. fumigatus killing assays in vitro and as adoptive cellular therapy in vivo. The expanded NK cells possessed potent killing activity at low effector-to-target ratio of 2:1. Fungicidal activity was morphotypal-dependent and most efficacious against A. fumigatus conidia. Fungicidal activity was mediated by dectin-1 receptors on the expanded NK cells leading to augmented release of perforin, resulting in enhanced direct cytolysis. In an immunocompromised mice pulmonary aspergillosis model, we showed that NK cell treatment significantly reduced fungal burden, hence demonstrating the translational potential of expanded NK cells as adjunctive therapy against IA in immunocompromised patients.

Importance: Remdesivir demonstrated clinical benefit in a placebo-controlled trial in patients with severe coronavirus disease 2019 (COVID-19), but its effect in patients with moderate disease is unknown., Objective: To determine the efficacy of 5 or 10 days of remdesivir treatment compared with standard care on clinical status on day 11 after initiation of treatment., Design, Setting, and Participants: Randomized, open-label trial of hospitalized patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and moderate COVID-19 pneumonia (pulmonary infiltrates and room-air oxygen saturation >94%) enrolled from March 15 through April 18, 2020, at 105 hospitals in the United States, Europe, and Asia. The date of final follow-up was May 20, 2020., Interventions: Patients were randomized in a 1:1:1 ratio to receive a 10-day course of remdesivir (n = 197), a 5-day course of remdesivir (n = 199), or standard care (n = 200). Remdesivir was dosed intravenously at 200 mg on day 1 followed by 100 mg/d., Main Outcomes and Measures: The primary end point was clinical status on day 11 on a 7-point ordinal scale ranging from death (category 1) to discharged (category 7). Differences between remdesivir treatment groups and standard care were calculated using proportional odds models and expressed as odds ratios. An odds ratio greater than 1 indicates difference in clinical status distribution toward category 7 for the remdesivir group vs the standard care group., Results: Among 596 patients who were randomized, 584 began the study and received remdesivir or continued standard care (median age, 57 [interquartile range, 46-66] years; 227 [39%] women; 56% had cardiovascular disease, 42% hypertension, and 40% diabetes), and 533 (91%) completed the trial. Median length of treatment was 5 days for patients in the 5-day remdesivir group and 6 days for patients in the 10-day remdesivir group. On day 11, patients in the 5-day remdesivir group had statistically significantly higher odds of a better clinical status distribution than those receiving standard care (odds ratio, 1.65; 95% CI, 1.09-2.48; P = .02). The clinical status distribution on day 11 between the 10-day remdesivir and standard care groups was not significantly different (P = .18 by Wilcoxon rank sum test). By day 28, 9 patients had died: 2 (1%) in the 5-day remdesivir group, 3 (2%) in the 10-day remdesivir group, and 4 (2%) in the standard care group. Nausea (10% vs 3%), hypokalemia (6% vs 2%), and headache (5% vs 3%) were more frequent among remdesivir-treated patients compared with standard care., Conclusions and Relevance: Among patients with moderate COVID-19, those randomized to a 10-day course of remdesivir did not have a statistically significant difference in clinical status compared with standard care at 11 days after initiation of treatment. Patients randomized to a 5-day course of remdesivir had a statistically significant difference in clinical status compared with standard care, but the difference was of uncertain clinical importance., Trial Registration: ClinicalTrials.gov Identifier: NCT04292730.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with a 382-nucleotide deletion (∆382) in the open reading frame 8 (ORF8) region of the genome have been detected in Singapore and other countries. We investigated the effect of this deletion on the clinical features of infection., Methods: We retrospectively identified patients who had been screened for the ∆382 variant and recruited to the PROTECT study-a prospective observational cohort study conducted at seven public hospitals in Singapore. We collected clinical, laboratory, and radiological data from patients' electronic medical records and serial blood and respiratory samples taken during hospitalisation and after discharge. Individuals infected with the ∆382 variant were compared with those infected with wild-type SARS-CoV-2. Exact logistic regression was used to examine the association between the infection groups and the development of hypoxia requiring supplemental oxygen (an indicator of severe COVID-19, the primary endpoint). Follow-up for the study's primary endpoint is completed., Findings: Between Jan 22 and March 21, 2020, 278 patients with PCR-confirmed SARS-CoV-2 infection were screened for the ∆382 deletion and 131 were enrolled onto the study, of whom 92 (70%) were infected with the wild-type virus, ten (8%) had a mix of wild-type and ∆382-variant viruses, and 29 (22%) had only the ∆382 variant. Development of hypoxia requiring supplemental oxygen was less frequent in the ∆382 variant group (0 [0%] of 29 patients) than in the wild-type only group (26 [28%] of 92; absolute difference 28% [95% CI 14-28]). After adjusting for age and presence of comorbidities, infection with the ∆382 variant only was associated with lower odds of developing hypoxia requiring supplemental oxygen (adjusted odds ratio 0·07 [95% CI 0·00-0·48]) compared with infection with wild-type virus only., Interpretation: The ∆382 variant of SARS-CoV-2 seems to be associated with a milder infection. The observed clinical effects of deletions in ORF8 could have implications for the development of treatments and vaccines., Funding: National Medical Research Council Singapore., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Streptococcus mutans is the principal biofilm forming oral pathogen associated with dental caries. Studies have shown that Candida albicans , a commensal oral fungus is capable of forming pathogenic mixed-species biofilms with S. mutans. The treatment of bacterial and fungal infections using conventional antimicrobial agents has become challenging due to the antimicrobial resistance of the biofilm mode of growth. The present study aimed to evaluate the efficacy of secretory components of Lactobacillus plantarum 108 , a potentially promising probiotic strain, against S. mutans and C. albicans single and mixed-species biofilms. L. plantarum 108 supernatant inhibited S. mutans and C. albicans single-species biofilms as shown by XTT reduction assay, crystal violet assay, and colony forming units counting. The probiotic supernatant significantly inhibited the S. mutans and C. albicans mixed-species biofilm formation. The pre-formed mixed-species biofilms were also successfully reduced. Confocal microscopy showed poorly developed biofilm architecture in the probiotic supernatant treated biofilms. Moreover, the expression of S. mutans genes associated with glucosyltransferase activity and C. albicans hyphal specific genes ( HWP1, ALS1 and ALS3 ) were down-regulated in the presence of the probiotic supernatant. Altogether, the data demonstrated the capacity of L. plantarum 108 supernatant to inhibit the S. mutans and C. albicans mixed-species biofilms. Herein, we provide a new insight on the potential of probiotic-based strategies to prevent bacterial-fungal mixed-species biofilms associated with dental caries.

Background: With at least 94 countries undergoing or exiting lockdowns for contact suppression to control the COVID-19 outbreak, sustainable and public health-driven exit strategies are required. Here we explore the impact of lockdown and exit strategies in Singapore for immediate planning., Methods: We use an agent-based model to examine the impacts of epidemic control over 480 days. A limited control baseline of case isolation and household member quarantining is used. We measure the impact of lockdown duration and start date on final infection attack sizes. We then apply a 3-month gradual exit strategy, immediately re-opening schools and easing workplace distancing measures, and compare this to long-term social distancing measures., Findings: At baseline, we estimated 815 400 total infections (21.6% of the population). Early lockdown at 5 weeks with no exit strategy averted 18 500 (2.27% of baseline averted), 21 300 (2.61%) and 22 400 (2.75%) infections for 6, 8 and 9-week lockdown durations. Using the exit strategy averted a corresponding 114 700, 121 700 and 126 000 total cases, representing 12.07-13.06% of the total epidemic size under baseline. This diminishes to 9 900-11 300 for a late 8-week start time. Long-term social distancing at 6 and 8-week durations are viable but less effective., Interpretation: Gradual release exit strategies are critical to maintain epidemic suppression under a new normal. We present final infection attack sizes assuming the ongoing importation of cases, which require preparation for a potential second epidemic wave due to ongoing epidemics elsewhere., Funding: Singapore Ministry of Health, Singapore Population Health Improvement Centre., Competing Interests: The authors declare no competing interests., (© 2020 The Author(s). Published by Elsevier Ltd.)

Objective: In invasive aspergillosis (IA), monitoring response to antifungal treatment is challenging. We aimed to explore if routine blood parameters help to anticipate outcomes following IA., Methods: Post hoc secondary analysis of two multicenter randomized trials was performed. The Global Comparative Aspergillosis Study (GCA, n = 123) and the Combination Antifungal Study (CAS, n = 251) constituted the discovery and validation cohorts respectively. The outcome measures were response to treatment and survival to 12 weeks. Interval platelet, galactomannan index (GMI) and C-reactive protein (CRP) levels prior and during antifungal treatment were analysed using logistic regression, Kaplan-Meier survival and receiver operating characteristic (ROC) analyses., Results: The 12-week survival was 70.7% and 63.7% for the GCA and CAS cohorts respectively. In the GCA cohort, every 10 × 10 9 /L platelet count increase at week 2 and 4 improved 12-week survival odds by 6-18% (odds ratio (OR) 1.06-1.18, 95% confidence interval (CI) 1.02-1.33). Survival odds also improved 13% with every 10 mg/dL CRP drop at week 1 and 2 (OR 0.87, 95% CI 0.78-0.97). In the CAS cohort, week 2 platelet count was also associated with 12-week survival with 10% improved odds for every 10 × 10 9 /L platelet increase (OR, 1.10, 95% CI 1.04-1.15). A GMI drop of 0.1 unit was additionally found to increase the odds of treatment response by 3% at the baseline of week 0 (OR 0.97, 95% CI 0.95-0.99). Week 2 platelet and CRP levels performed better than GMI on ROC analyses for survival (area under ROC curve 0.76, 0.87 and 0.67 respectively). A baseline platelet count higher than 30 × 10 9 /L clearly identified patients with >75% survival probability., Conclusions: Higher serial platelets were associated with overall survival while GMI trends were linked to IA treatment response. Routine and simple laboratory indices may aid follow-up of response in IA patients., (Copyright © 2019 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Given the ongoing SARS-CoV-2 pandemic, identification of immunogenic targets against the coronavirus spike glycoprotein will provide crucial advances towards the development of sensitive diagnostic tools and potential vaccine candidate targets. In this study, using pools of overlapping linear B-cell peptides, we report two IgG immunodominant regions on SARS-CoV-2 spike glycoprotein that are recognised by sera from COVID-19 convalescent patients. Notably, one is specific to SARS-CoV-2, which is located in close proximity to the receptor binding domain. The other region, which is localised at the fusion peptide, could potentially function as a pan-SARS target. Functionally, antibody depletion assays demonstrate that antibodies targeting these immunodominant regions significantly alter virus neutralisation capacities. Taken together, identification and validation of these neutralising B-cell epitopes will provide insights towards the design of diagnostics and vaccine candidates against this high priority coronavirus.

In invasive aspergillosis (IA), an early and adequate assessment of the response to the initial antifungal therapy remains problematic. We retrospectively analyzed 206 hematology patients with proven or probable IA, and collected serial serum galactomannan (sGM) values and survival status through week 6 and week 12. We created a model for survival at week 6 based on the sGM taken at baseline and on early sGM kinetics. This resulted in a rule predicting that patients with a baseline sGM index >1.4, who failed to lower that index to <0.5 after one week, had a mortality rate of 48.1% at week 6. Conversely, patients presenting with a baseline sGM index ≤1.4 that obtained a negative sGM (<0.5) after one week, had a mortality that was almost five times lower at only 10.1% by week 6. These findings were confirmed in an external cohort from an independent prospective study. In conclusion, sGM kinetics correlate well with treatment outcomes in hematology patients with IA. We present a rule which is easy to use at the bedside and has good accuracy in predicting week 6 survival., Competing Interests: T.M. received an unrestricted research grant from Gilead Sciences; served as a consultant for Gilead Sciences, Pfizer, and Celgene; and received non-financial support from MSD/Merck, Gilead Sciences, Pfizer, OLM Diagnostics, IMMY, and FUJIFILM Wako. K.L. received consultancy fees from MSD, SMB Laboratoires Brussels, and Gilead; travel support from Pfizer and MSD; and speaker fees from Gilead, MSD, FUJIFILM WAKO and Pfizer. J.M. received research grants from Merck/MSD, Gilead Sciences and Pfizer; is a consultant to Astellas, Basilea, Bio‐Rad, Merck/MSD, Pfizer, Schering‐Plough, F2G, Gilead Sciences, Cidara, Scynexis, Amplyx and Luminex; and served on the speaker's bureau of Astellas, Gilead Sciences, Bio‐Rad, Merck/MSD, Pfizer, F2G, Schering‐Plough, Basilea and Shire/Takeda. L.C. has received grant support and has been advisor/consultant for Pfizer, Gilead, Astellas and Merck Sharp and Dohme (MSD). J.W. has no conflicts to report.

Natural killer (NK) cells are innate lymphocytes that directly kill tumor and pathogen-infected cells upon activation by cytokines and NK cell receptors (NKRs) without previous sensitization. It is known that cell metabolism affects the differentiation and effector functions of immune cells. For instance, interleukin-2 and interleukin-15 treatment increases glycolysis and oxidative phosphorylation (OXPHOS) in NK cells to support their effector functions. However, little is known about the metabolic reprogramming of human NK cells upon their activation by NKRs. In this study, we investigated the metabolism of NK cells stimulated via NKRs. We found that NK cells upregulated glycolysis and OXPHOS in response to anti-CD16 antibody or NKG2D ligand engagement. Inhibition of either glycolysis or OXPHOS impaired NK cell production of interferon-γ. Interestingly, inhibition of glycolysis but not OXPHOS decreased NK cell killing and dampened NK cell degranulation and Fas ligand expression, suggesting that glycolysis is more critical for NKR-activated cell cytotoxicity. Thus, our study provides insight into understanding the metabolic requirements underlying different effector functions of human NK cells., (Copyright © 2020 Wang, Guan, Wang, Chai, Xu and Lam.)

Immunodeficiency secondary to anti-interferon-gamma (anti-IFN-γ) autoantibodies was first described in 2004 as an acquired defect in the IFN-γ pathway leading to susceptibility to multiple opportunistic infections, including dimorphic fungi, parasites, and bacteria, especially tuberculosis and non-tuberculous mycobacterium (NTM) species. It has so far only been described in adult patients. We present 2 cases of disseminated NTM infections in otherwise immunocompetent children. A 16-year-old girl with Sweet's syndrome-like neutrophilic dermatosis developed recurrent fever and cervical lymphadenitis secondary to Mycobacterium abscessus. A 10-year-old boy with a history of prolonged fever, aseptic meningitis, aortitis, and arteritis in multiple blood vessels developed thoracic vertebral osteomyelitis secondary to Mycobacterium avium complex. Both patients were found to have positive serum neutralizing anti-IFNγ autoantibodies. Testing for anti-IFNγ autoantibodies should be considered in otherwise healthy immunocompetent hosts with recurrent or disseminated NTM infection. This represents a phenocopy of primary immunodeficiency which has been recently described only in adults. We report the first two cases of this phenomenon to affect children.

Febrile neutropenia (FN) is associated with substantial morbidity and necessitates empirical broad-spectrum antimicrobial treatment. In this prospective cohort study, a risk-guided management strategy for FN using empirical piperacillin/tazobactam (TZP) or a carbapenem was evaluated. The analysis involved 723 FN episodes in hospitalised adult patients, including those with severe sepsis or prior infection/colonisation with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. Propensity score matching analysis was used to adjust for baseline differences between treatment groups and produced 267 matched pairs. The primary outcome was all-cause mortality. Secondary outcomes were the incidences of drug-resistant Gram-negative (including ESBL-producing) and Gram-positive bacterial isolates and of invasive pulmonary aspergillosis (IPA) and their associated mortality. There was no difference in mortality between empirical carbapenem and TZP [18/267 (6.7%) vs. 14/267 (5.2%); P = 0.466]. Higher incidences of drug-resistant Gram-negative isolates [77/267 (28.8%) vs. 26/267 (9.7%); P < 0.001], including ESBL-producing bacteria [57/267 (21.3%) vs. 16/267 (6.0%); P < 0.001], were observed in carbapenem-treated episodes where its use lowered mortality. Mortality rates for ESBL-positive infections were 5.3% (3/57) and 25.0% (4/16) (P = 0.037) and for drug-resistant Gram-negative infections were 6.5% (5/77) and 23.1% (6/26) (P = 0.018) in carbapenem- and TZP-treated episodes, respectively. More IPA was observed with carbapenem use [16/267 (6.0%) vs. 6/267 (2.2%); P = 0.029]. Antifungal prophylaxis reduced the risk of death (odds ratio = 0.39, 95% confidence interval 0.17-0.87; P = 0.017). Risk-guided carbapenem prescribing in FN correctly identified cases prone to drug-resistant Gram-negative infections and reduced the mortality in these episodes., (Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.)

Dengue virus and Zika virus coexist in tropical regions in Asia where healthcare resources are limited; differentiating the 2 viruses is challenging. We showed in a case-control discovery cohort, and replicated in a validation cohort, that the diagnostic indices of conjunctivitis, platelet count, and monocyte count reliably distinguished between these viruses.

Invasive fungal disease (IFD) causes significant morbidity in immunocompromised patients due to their weakened immune system. Immunomodulatory therapy, in synergy with existing antifungal therapy, is an attractive option to enhance their immune system and aid clearance of these opportunistic pathogens. From a scientific and clinical perspective, we explore the immunotherapeutic options to augment standard antifungal drugs for patients with an IFD. We discuss the range of immunomodulatory therapies being considered in IFD - from cytokines, including G-CSF, GM-CSF, M-CSF, IFN-γ, and cytokine agonists, to cellular therapies, consisting of granulocyte transfusion, adoptive T-cell, CAR T-cell, natural killer cell therapies, and monoclonal antibodies. Adjunct pharmaceutical agents which augment the immunity are also being considered. Lastly, we explore the likelihood of the use of probiotics and manipulation of the microbiome/mycobiome to enhance IFD treatment outcomes.