Infectious complications and vaccines.

Infections are a major cause of morbidity and can result in mortality in long-term survivors after allogeneic hematopoietic cell transplantation. Chronic graft-versus-host disease and delayed immune reconstitution are recognized risk factors. Different strategies must be utilized depending on the individual patient's situation but include prolonged antimicrobial prophylaxis and vaccination. Some important infections due to pathogens preventable by vaccination are pneumococci, influenza, varicella-zoster virus, and SARS-CoV-2. Despite the fact that such recommendations have been in place for decades, implementation of these recommendations has been reported to be poor.

A Randomized Clinical Trial of Anti-IL-6 Antibody Clazakizumab in Late Antibody-Mediated Kidney Transplant Rejection.

BACKGROUND: Late antibody-mediated rejection (ABMR) is a leading cause of transplant failure. Blocking IL-6 has been proposed as a promising therapeutic strategy. METHODS: We performed a phase 2 randomized pilot trial to evaluate the safety (primary endpoint) and efficacy (secondary endpoint analysis) of the anti-IL-6 antibody clazakizumab in late ABMR. The trial included 20 kidney transplant recipients with donor-specific, antibody-positive ABMR ≥365 days post-transplantation. Patients were randomized 1:1 to receive 25 mg clazakizumab or placebo (4-weekly subcutaneous injections) for 12 weeks (part A), followed by a 40-week open-label extension (part B), during which time all participants received clazakizumab. RESULTS: Five (25%) patients under active treatment developed serious infectious events, and two (10%) developed diverticular disease complications, leading to trial withdrawal. Those receiving clazakizumab displayed significantly decreased donor-specific antibodies and, on prolonged treatment, modulated rejection-related gene-expression patterns. In 18 patients, allograft biopsies after 51 weeks revealed a negative molecular ABMR score in seven (38.9%), disappearance of capillary C4d deposits in five (27.8%), and resolution of morphologic ABMR activity in four (22.2%). Although proteinuria remained stable, the mean eGFR decline during part A was slower with clazakizumab compared with placebo (-0.96; 95% confidence interval [95% CI], -1.96 to 0.03 versus -2.43; 95% CI, -3.40 to -1.46 ml/min per 1.73 m2 per month, respectively, P=0.04). During part B, the slope of eGFR decline for patients who were switched from placebo to clazakizumab improved and no longer differed significantly from patients initially allocated to clazakizumab. CONCLUSIONS: Although safety data indicate the need for careful patient selection and monitoring, our preliminary efficacy results suggest a potentially beneficial effect of clazakizumab on ABMR activity and progression.

Risk factors for unfavorable outcome and impact of early post-transplant infection in solid organ recipients with COVID-19: A prospective multicenter cohort study.

The aim was to analyze the characteristics and predictors of unfavorable outcomes in solid organ transplant recipients (SOTRs) with COVID-19. We conducted a prospective observational cohort study of 210 consecutive SOTRs hospitalized with COVID-19 in 12 Spanish centers from 21 February to 6 May 2020. Data pertaining to demographics, chronic underlying diseases, transplantation features, clinical, therapeutics, and complications were collected. The primary endpoint was a composite of intensive care unit (ICU) admission and/or death. Logistic regression analyses were performed to identify the factors associated with these unfavorable outcomes. Males accounted for 148 (70.5%) patients, the median age was 63 years, and 189 (90.0%) patients had pneumonia. Common symptoms were fever, cough, gastrointestinal disturbances, and dyspnea. The most used antiviral or host-targeted therapies included hydroxychloroquine 193/200 (96.5%), lopinavir/ritonavir 91/200 (45.5%), and tocilizumab 49/200 (24.5%). Thirty-seven (17.6%) patients required ICU admission, 12 (5.7%) suffered graft dysfunction, and 45 (21.4%) died. A shorter interval between transplantation and COVID-19 diagnosis had a negative impact on clinical prognosis. Four baseline features were identified as independent predictors of intensive care need or death: advanced age, high respiratory rate, lymphopenia, and elevated level of lactate dehydrogenase. In summary, this study presents comprehensive information on characteristics and complications of COVID-19 in hospitalized SOTRs and provides indicators available upon hospital admission for the identification of SOTRs at risk of critical disease or death, underlining the need for stringent preventative measures in the early post-transplant period.

Immunological lessons from genome-wide association studies of infections.

Over the past few years, genome-wide association studies (GWAS) have been increasingly applied to identify host genetic factors influencing clinical and laboratory traits related to immunity and infection, and to understand the interplay between the host and the microbial genomes. By screening large cohorts of individuals suffering from various infectious diseases, GWAS explored resistance against infection, natural history of the disease, development of life-threatening clinical signs, and innate and adaptive immune responses. These efforts provided fundamental insight on the role of major genes in the interindividual variability in the response to infection and on the mechanisms of the immune response against human pathogens both at the individual and population levels.

Patient-Directed Home Drain Removal in Head and Neck Surgery.

OBJECTIVES/HYPOTHESIS: The purpose of this study was to evaluate the efficacy and safety of at home drain removal in head and neck surgery patients. METHODS: The study population included patients who underwent head and neck surgery at an academic tertiary care center between February 2020 and November 2020 and were discharged with one to four drains with instructions for home removal. Prior to discharge, patients received thorough drain removal education. Patients were prospectively followed to evaluate for associated outcomes. RESULTS: One hundred patients were evaluated in the study. There was record for ninety-seven patients receiving education at discharge. The most common methods of education were face-to-face education and written instructions with educational video link provided. Of 123 drains upon discharge, 110 drains (89.4%) were removed at home while 13 (10.6%) were removed in office. Most drains were located in the neck (86.4%). There was one seroma, two hematomas, two drain site infections, and five ED visits; however, none of these complications were directly associated with the action of drain removal at home. Calculated cost savings for travel and lost wages was $259.82 per round trip saved. CONCLUSIONS: The results demonstrate that home drain removal can provide a safe and efficacious option for patients following head and neck surgery. This approach was safe and associated with patient cost savings and better utilization of provider's time. Furthermore, patients and healthcare providers avoided additional in-person encounters and exposures during the COVID-19 pandemic. Our findings warrant further investigation into cost savings and formal patient satisfaction associated with home drain removal. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2471-2477, 2021.

Secondary infections in mechanically ventilated patients with COVID-19: An overlooked matter?

OBJECTIVE: The susceptibility to infection probably increases in COVID-19 patients due to a combination of virusand drug-induced immunosuppression. The reported rate of secondary infections was quite low in previous studies. The objectives of our study were to investigate the rate of secondary infections, risk factors for secondary infections and risk factors for mortality in COVID-19 critically ill patients. METHODS: We performed a single-center retrospective study in mechanically ventilated critically ill COVID-19 patients admitted to our Critical Care Unit (CCU). We recorded the patients' demographic data; clinical data; microbiology data and incidence of secondary infection during CCU stay, including ventilator-associated pneumonia (VAP) and nosocomial bacteremia (primary and secondary). RESULTS: A total of 107 patients with a mean age 62.2 ± 10.6 years were included. Incidence of secondary infection during CCU stay was 43.0% (46 patients), including nosocomial bacteremia (34 patients) and VAP (35 patients). Age was related to development of secondary infection (65.2 ± 7.3 vs. 59.9 ± 12.2 years, p=0.007). Age ≥ 65 years and secondary infection were independent predictors of mortality (OR=2.692, 95% CI 1.068-6.782, p<0.036; and OR=3.658, 95% CI 1.385- 9.660, p=0.009, respectively). The hazard ratio for death within 90 days in the ≥ 65 years group and in patients infected by antimicrobial resistant pathogens was 1.901 (95% CI 1.198- 3.018; p= 0.005 by log-rank test) and 1.787 (95% CI 1.023-3.122; p= 0.036 by log-rank test), respectively. CONCLUSIONS: Our data suggest that the incidence of secondary infection and infection by antimicrobial resistant pathogens is very high in critically ill patients with COVID-19 with a significant impact on prognosis.

Mid-regional pro-adrenomedullin as a supplementary tool to clinical parameters in cases of suspicion of infection in the emergency department.

INTRODUCTION: Mid-regional proadrenomedullin (MR-proADM), a novel biomarker, has recently gained interest particularly with regards to its potential in assisting clinicians' decision making in patients with suspicion of infection in the emergency department (ED). A group of international experts, with research and experience in MR-proADM applications, produced this review based on their own experience and the currently available literature. AREAS COVERED: The review provides evidence related to MR-proADM as a triaging tool in avoiding unnecessary admissions to hospital and/or inadequate discharge, and identifying patients most at risk of deterioration. It also covers the use of MR-proADM in the context of COVID-19. Moreover, the authors provide a proposal on how to incorporate MR-proADM into patients' clinical pathways in an ED setting. EXPERT OPINION: The data we have so far on the application of MR-proADM in the ED is promising. Incorporating it into clinical scoring systems may aid the clinician's decision making and recognizing the 'ill looking well' and the 'well looking ill' sooner. However there are still many gaps in our knowledge especially during the ongoing COVID-19 waves. There is also a need for cost-effectiveness analysis studies especially in the era of increasing cost pressures on health systems globally.

Preventing infections in children and adults with asplenia.

An estimated 1 million people in the United States have functional or anatomic asplenia or hyposplenia. Infectious complications due to encapsulated organisms such as Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae can lead to fulminant sepsis and death, particularly in young children, in the period shortly after splenectomy, and in immunocompromised patients. Patients with asplenia are also at risk for less common infections due to Capnocytophaga, Babesia, and malaria. Antibiotic prophylaxis, vaccines, and patient and family education are the mainstays of prevention in these at-risk patients. Recommendations for antibiotic prophylaxis typically target high-risk periods, such as 1 to 3 years after splenectomy, children ≤5 years of age, or patients with concomitant immunocompromise. However, the risk for sepsis is lifelong, with infections occurring as late as 40 years after splenectomy. Currently available vaccines recommended for patients with asplenia include pneumococcal vaccines (13-valent pneumococcal conjugate vaccine followed by the 23-valent pneumococcal polysaccharide vaccine), meningococcal vaccines (meningococcal conjugate vaccines for serogroups A, C, Y and W-135 and serogroup B meningococcal vaccines), H. influenzae type b vaccines, and inactivated influenza vaccines. Ongoing booster doses are also recommended for pneumococcal and meningococcal vaccines to maintain protection. Despite the availability of prevention tools, adherence is often a challenge. Dedicated teams or clinics focused on patient education and monitoring have demonstrated substantial improvements in vaccine coverage rates for individuals with asplenia and reduced risk of infection. Future efforts to monitor the quality of care in patients with asplenia may be important to bridge the know-do gap in this high-risk population.

Germinal Center and Extrafollicular B Cell Responses in Vaccination, Immunity, and Autoimmunity.

Activated B cells participate in either extrafollicular (EF) or germinal center (GC) responses. Canonical responses are composed of a short wave of plasmablasts (PBs) arising from EF sites, followed by GC producing somatically mutated memory B cells (MBC) and long-lived plasma cells. However, somatic hypermutation (SHM) and affinity maturation can take place at both sites, and a substantial fraction of MBC are produced prior to GC formation. Infection responses range from GC responses that persist for months to persistent EF responses with dominant suppression of GCs. Here, we review the current understanding of the functional output of EF and GC responses and the molecular switches promoting them. We discuss the signals that regulate the magnitude and duration of these responses, and outline gaps in knowledge and important areas of inquiry. Understanding such molecular switches will be critical for vaccine development, interpretation of vaccine efficacy and the treatment for autoimmune diseases.

The impact of COVID-19 on cervicofacial infection of dental aetiology.

Cervicofacial infections of dental aetiology can be life-threatening and with the closure of dental practices following the onset of the COVID-19, it would be anticipated that their prevalence presenting to maxillofacial surgery would increase and services may be overwhelmed, with patients presenting later with a potential subsequent increase in morbidity. A retrospective analysis of patients with cervicofacial infection of dental aetiology referred to maxillofacial surgery during the initial six weeks of COVID-19 lockdown in 2020 was carried out and compared with the equivalent period in the two preceding years. Unexpectedly, during COVID-19 lockdown, there was a reduction in patients seen with cervicofacial infection of dental aetiology. This may have resulted from patient adherence to government guidelines "Stay at home", successful triaging of patients in primary care and emergency treatment provided by urgent dental care centres. Proportionally more patients who presented to hospital had received prior antibiotic therapy and required in-patient admission. All patients admitted received incision and drainage, with an increase extraoral drainage and an associated reduction in length of stay. During COVID-19 lockdown, maxillofacial managed a reduced number of patients with cervicofacial infection, likely resulting from primary and secondary dental care working together. The rate of incision and drainage of patients not admitted increased under local anaesthesia with increase of extraoral drainage and reduced length of stay for those admitted.