The Influence of Social Determinants on Receiving Outpatient Treatment with Monoclonal Antibodies, Disease Risk, and Effectiveness for COVID-19

BACKGROUND

Limited research has studied the influence of social determinants of health (SDoH) on the receipt, disease risk, and subsequent effectiveness of neutralizing monoclonal antibodies (nMAbs) for outpatient treatment of COVID-19.

OBJECTIVE

To examine the influence of SDoH variables on receiving nMAb treatments and the risk of a poor COVID-19 outcome, as well as nMAb treatment effectiveness across SDoH subgroups.

DESIGN

Retrospective observational study utilizing electronic health record data from four health systems. SDoH variables analyzed included race, ethnicity, insurance, marital status, Area Deprivation Index, and population density.

PARTICIPANTS

COVID-19 patients who met at least one emergency use authorization criterion for nMAb treatment.

MAIN MEASURE

We used binary logistic regression to examine the influence of SDoH variables on receiving nMAb treatments and risk of a poor outcome from COVID-19 and marginal structural models to study treatment effectiveness.

RESULTS

The study population included 25,241 (15.1%) nMAb-treated and 141,942 (84.9%) non-treated patients. Black or African American patients were less likely to receive treatment than white non-Hispanic patients (adjusted odds ratio (OR) = 0.86; 95% CI = 0.82-0.91). Patients who were on Medicaid, divorced or widowed, living in rural areas, or living in areas with the highest Area Deprivation Index (most vulnerable) had lower odds of receiving nMAb treatment, but a higher risk of a poor outcome. For example, compared to patients on private insurance, Medicaid patients had 0.89 (95% CI = 0.84-0.93) times the odds of receiving nMAb treatment, but 1.18 (95% CI = 1.13-1.24) times the odds of a poor COVID-19 outcome. Age, comorbidities, and COVID-19 vaccination status had a stronger influence on risk of a poor outcome than SDoH variables. nMAb treatment benefited all SDoH subgroups with lower rates of 14-day hospitalization and 30-day mortality.

CONCLUSION

Disparities existed in receiving nMAbs within SDoH subgroups despite the benefit of treatment across subgroups.

Inclusion, Diversity, Access, and Equity in Infectious Diseases Fellowship Training: Tools for Program Directors

The Infectious Diseases Society of America (IDSA) has set clear priorities in recent years to promote inclusion, diversity, access, and equity (IDA&E) in infectious disease (ID) clinical practice, medical education, and research. The IDSA IDA&E Task Force was launched in 2018 to ensure implementation of these principles. The IDSA Training Program Directors Committee met in 2021 and discussed IDA&E best practices as they pertain to the education of ID fellows. Committee members sought to develop specific goals and strategies related to recruitment, clinical training, didactics, and faculty development. This article represents a presentation of ideas brought forth at the meeting in those spheres and is meant to serve as a reference document for ID training program directors seeking guidance in this area.

Immunomodulators for severe coronavirus disease-2019 in transplant patients: Do they increase the risk of secondary infection?

BACKGROUND

Current guidelines recommend immunomodulators, tocilizumab or baricitinib, for the management of severe coronavirus disease-2019 (COVID-19) in patients with increasing oxygen requirements. Given their immunosuppressive effects, there is a concern for higher rates of infection among transplant recipients.

METHODS

A retrospective cohort study of transplant patients with severe COVID-19 between April 2020 and January 2022 was performed at the Mayo Clinic. The primary outcome was incidence of secondary infections after COVID-19 diagnosis. Secondary outcomes were 90-day mortality, ventilatory days, and thromboembolic events.

RESULTS

A total of 191 hospitalized transplant patients were studied, including 77 (40.3%) patients who received an immunomodulator. Overall, 89% were solid organ transplant recipients, with kidney as the most common transplanted organ (50.3%). The majority (89.0%) required oxygen supplementation on admission, and 39.8% of these patients required mechanical ventilation during the hospital course. There was no significant difference in the incidence of secondary infections between those who received or did not receive an immunomodulator (p = .984). Likewise, there was no difference in 90-day mortality between patients who received or did not receive an immunomodulator (p = .134). However, higher mortality was observed among patients that developed a secondary infection (p < .001).

CONCLUSION

The use of immunomodulators in transplant patients with severe COVID-19 was not significantly associated with an increased risk of secondary infections. Secondary infections were associated with higher risk of all-cause mortality. Future studies of larger cohorts are needed to explore the effect of immunomodulators on survival among transplant patients with COVID-19.

A consensus conference to define the utility of advanced infectious disease diagnostics in solid organ transplant recipients

The last decade has seen an explosion of advanced assays for the diagnosis of infectious diseases, yet evidence-based recommendations to inform their optimal use in the care of transplant recipients are lacking. A consensus conference sponsored by the American Society of Transplantation (AST) was convened on December 7, 2021, to define the utility of novel infectious disease diagnostics in organ transplant recipients. The conference represented a collaborative effort by experts in transplant infectious diseases, diagnostic stewardship, and clinical microbiology from centers across North America to evaluate current uses, unmet needs, and future directions for assays in 5 categories including (1) multiplex molecular assays, (2) rapid antimicrobial resistance detection methods, (3) pathogen-specific T-cell reactivity assays, (4) next-generation sequencing assays, and (5) mass spectrometry-based assays. Participants reviewed and appraised available literature, determined assay advantages and limitations, developed best practice guidance largely based on expert opinion for clinical use, and identified areas of future investigation in the setting of transplantation. In addition, attendees emphasized the need for well-designed studies to generate high-quality evidence needed to guide care, identified regulatory and financial barriers, and discussed the role of regulatory agencies in facilitating research and implementation of these assays. Findings and consensus statements are presented.

Absolute lymphocyte count as marker of cytomegalovirus and allograft rejection: Is there a "Safe Corridor" after kidney transplantation?

The contrasting outcomes of lymphocyte manipulation after solid organ transplantation are allograft rejection and infections, commonly with cytomegalovirus (CMV). Peripheral blood absolute lymphocyte count (ALC) may serve as a predictive marker for these outcomes. Using a retrospective review of clinical and laboratory dataset, we aimed to determine whether a range of ALC (termed "safe ALC corridor") exists where CMV infection and rejection outcomes are minimal in a cohort of 381 kidney transplant recipients. In an extended Cox model using a time-dependent covariate for peripheral blood ALC, a value below the cut-off of 610 cells/uL was associated with the development of CMV infection both in the overall cohort (Hazard Ratio [HR] 2.25 (95% confidence internal [CI] 1.02-4.96; P = .043) and the subgroup of high-risk CMV D+/R- mismatch patients (HR 2.91 [95% CI 1.09-7.77]; P = .033). In contrast, a time-dependent Cox analysis did not show any significant association between ALC and rejection (per IQR decrease, HR 1.2 [95% CI: 0.76-1.9]; P = .434). Accordingly, a "safe ALC corridor" could not be defined. In conclusion, a low peripheral blood ALC (ie, threshold of 610 cells/uL) can be used to stratify the risk of CMV disease after kidney transplantation.

Use of Viral Load as a Surrogate Marker in Clinical Studies of Cytomegalovirus in Solid Organ Transplantation: A Systematic Review and Meta-analysis

Symptomatic cytomegalovirus (CMV) disease has been the standard endpoint for clinical trials in organ transplant recipients. Viral load may be a more relevant endpoint due to low frequency of disease. We performed a meta-analysis and systematic review of the literature. We found several lines of evidence to support the validity of viral load as an appropriate surrogate end-point, including the following: (1) viral loads in CMV disease are significantly greater than in asymptomatic viremia (odds ratio, 9.3 95% confidence interval, 4.6-19.3); (2) kinetics of viral replication are strongly associated with progression to disease; (3) pooled incidence of CMV viremia and disease is significantly lower during prophylaxis compared with the full patient follow-up period (viremia incidence: 3.2% vs 34.3%; P < .001) (disease incidence: 1.1% vs 13.0%; P < .001); (4) treatment of viremia prevented disease; and (5) viral load decline correlated with symptom resolution. Based on the analysis, we conclude that CMV load is an appropriate surrogate endpoint for CMV trials in organ transplant recipients.

Effects of clotrimazole troches on tacrolimus dosing in heart transplant recipients

BACKGROUND

Tacrolimus is a cornerstone of immunosuppression after transplantation but is highly susceptible to changes from interacting variables and has a narrow therapeutic index. Clotrimazole troches are commonly used as a non-systemic antifungal to prevent oral candidiasis. Studies suggest that clotrimazole troches, though minimally absorbed systemically, may affect tacrolimus concentrations by inhibition of metabolic enzyme activity in the intestines. However, the magnitude of the impact of clotrimazole on tacrolimus dosing requirements to maintain goal levels is not well described.

METHODS

To assess this, tacrolimus dose adjustments and trough concentrations were retrospectively examined in 95 heart transplant recipients before and after the discontinuation of clotrimazole.

RESULTS

The median percent tacrolimus dose change was an increase of 66.7% (IQR 28.6%, 100%) after clotrimazole discontinuation, and the median trough concentration percent change from baseline to the first trough after clotrimazole discontinuation (in the absence of a dose change) was -42.5% (IQR -52.3%, -30.9%). Five cases of allograft rejection were observed.

CONCLUSION

In conclusion, clotrimazole troches exert a meaningful interaction with tacrolimus that requires close monitoring and dose adjustment. The data from this single-center study provide novel information that could guide providers on the degree of tacrolimus dose adjustment needed when discontinuing clotrimazole prophylaxis after heart transplantation.

Anti-infective chemoprophylaxis after solid-organ transplantation

INTRODUCTION

Solid organ transplant (SOT) recipients are at high risk of opportunistic infections due to bacterial, viral, fungal, and parasitic pathogens. Anti-infective prophylaxis is a time-tested proven strategy for the prevention of these infections after SOT. Areas covered: The current recommendations for the prevention of surgical site infections, herpes simplex, cytomegalovirus, invasive fungal infections, and selected parasitic diseases are highlighted. Recent peer-reviewed publications on the prevention of infection after SOT were reviewed and their significance was discussed in the context of the current recommendations for preventing infectious complications. Expert commentary: The authors comment on the current approaches to infection prevention in transplant recipients, and discuss how these recommendations are implemented in their clinical practice. Notable findings published during the past year were highlighted, and their clinical significance was interpreted in the context of current recommendations. The evolution of diagnostic and immunologic assays was emphasized, with focus on their potential role in optimizing the current antimicrobial approaches to infection prevention after SOT.