Adjunctive glucocorticoid therapy for Pneumocystis jirovecii pneumonia in solid organ transplant recipients: A multicenter cohort, 2015-2020.

Solid organ transplant recipients (SOTRs) frequently receive adjunctive glucocorticoid therapy (AGT) for Pneumocystis jirovecii pneumonia (PJP). This multicenter cohort of SOTRs with PJP admitted to 20 transplant centers in Canada, the United States, Europe, and Australia, was examined for whether AGT was associated with a lower rate of all-cause intensive care unit (ICU) admission, 90-day death, or a composite outcome (ICU admission or death). Of 172 SOTRs with PJP (median [IQR] age: 60 (51.5-67.0) years; 58 female [33.7%]), the ICU admission and death rates were 43.4%, and 20.8%, respectively. AGT was not associated with a reduced risk of ICU admission (adjusted odds ratio [aOR] [95% CI]: 0.49 [0.21-1.12]), death (aOR [95% CI]: 0.80 [0.30-2.17]), or the composite outcome (aOR [95% CI]: 0.97 [0.71-1.31]) in the propensity score-adjusted analysis. AGT was not significantly associated with at least 1 unit of the respiratory portion of the Sequential Organ Failure Assessment score improvement by day 5 (12/37 [32.4%] vs 39/111 [35.1%]; P = .78). We did not observe significant associations between AGT and ICU admission or death in SOTRs with PJP. Our findings should prompt a reevaluation of routine AGT administration in posttransplant PJP treatment and highlight the need for interventional studies.

Pathogen-agnostic immune biomarkers that predict infection after solid organ transplantation.

Solid organ transplant recipients (SOTRs) remain at high risk for infection throughout their post-transplant course. Dosing of immunosuppressive medications, strategies that prevent infection, and choice of empiric antimicrobial treatment could be optimized by a better understanding of an individual patient's risk for infectious complications. Diagnostic tests that qualitatively or quantitatively measure the function of the immune system and/or its response to infection may be useful for individualized management decisions. Numerous studies have identified an association between infectious outcomes after solid organ transplantation (SOT) and the results of a variety of non-pathogen-specific or "pathogen-agnostic" immune monitoring tests. These biomarkers include humoral immune markers, functional or quantitative assessments of cellular immunity, transcriptomic-based diagnostics, and replication of viruses within the human virome, which have been used to predict or diagnose a variety of different infectious diseases complicating SOT. In this narrative review, we discuss several host-derived immune biomarkers that show promise for either predicting or diagnosing infection among SOTRs. However, additional studies are needed to determine the optimal use of immune response testing. Whether immune biomarkers contribute added benefits to current standard clinical care has not yet been determined. Testing must be validated across a range of clinical scenarios, including surveillance to predict infection risk and diagnosis of active infection at various time points post transplant.

Consensus Definitions of BK Polyomavirus Nephropathy in Renal Transplant Recipients for Clinical Trials.

BACKGROUND: BK polyomavirus (BKPyV) infection and BK polyomavirus nephropathy (BKPyVAN) are important causes of allograft dysfunction and premature allograft loss in renal transplant recipients. RESULTS AND DISCUSSION: Controlled clinical trials to evaluate new agents for prevention and treatment are needed but are hampered by the lack of outcome measures that accurately assess the effect of the intervention, are clinically relevant, and are acceptable from a regulatory perspective. METHODS: To facilitate consistent end points in clinical trials and to support clinical research and drug development, definitions of BKPyV infection and disease have been developed by the BK Disease Definitions Working Group of the Transplantation Associated Virus Infection Forum with the Forum for Collaborative Research, which consists of scientists, clinicians, regulators, and industry representatives. CONCLUSIONS: These definitions refine established principles of "proven" BKPyV disease and introduce a "probable" disease category that could be used in clinical trials to prevent or treat BKPyVAN in renal transplant recipients.

Shorter is better: The case for short antibiotic courses for common infections in solid organ transplant recipients.

BACKGROUND: Prolonged antibiotics are associated with toxicity, selection for resistant organisms, and secondary infections such as Clostridioides difficile colitis. Emerging clinical data suggest that short courses of antibiotics can be used for common bacterial infections among immune competent patients, but for many randomized controlled trials (RCTs), immunocompromised patients, including solid organ transplant recipients (SOTRs), have been excluded. METHODS: Peer-reviewed publications were identified through PubMed and Embase searches. RESULTS: We review data examining shorter antibiotic courses among immunocompetent and immunocompromised patients and the rationale for use of short antibiotic courses in SOTRs. CONCLUSION: There are known harms associated with antibiotics and, when studied, existing data do not demonstrate harm associated with shorter courses of antibiotics among SOTRs. Furthermore, several RCTs did include some immune compromised patients and found shorter therapy to result in similar clinical efficacy with diminished adverse effects. Shorter antibiotic durations should be considered in SOTRs, and questions of antibiotic duration among SOTRs should be prioritized for study in clinical trials.

Risk Factors for Cytomegalovirus Reactivation and Association With Outcomes in Critically Ill Adults With Sepsis: A Pooled Analysis of Prospective Studies.

We performed multivariable analysis of potential risk factors (including cytomegalovirus [CMV] reactivation) for clinical outcomes by day 28 (death or continued hospitalization, ventilator-free days, intensive care unit (ICU)-free days, hospital-free days) from pooled cohorts of 2 previous prospective studies of CMV-seropositive adults with sepsis. CMV reactivation at any level, >100 IU/mL, >1000 IU/mL, peak viral load, and area under the curve were independently associated with the clinical outcomes. We identified the potential effect size of CMV on outcomes that could be used as end points for future interventional trials of CMV prevention using antiviral prophylaxis in ICU patients with sepsis.

Letermovir and Maribavir for the Treatment and Prevention of Cytomegalovirus Infection in Solid Organ and Stem Cell Transplant Recipients.

Until recently, available drugs for cytomegalovirus (CMV) prevention and treatment in transplant patients included (val)ganciclovir, foscarnet, and cidofovir. Use of these drugs is limited by toxicity and the development of resistance. The 2017 approval of letermovir for prevention of CMV after stem cell transplant marked the first approval of an anti-CMV agent since 2003. The role of letermovir in treatment of established CMV infection or disease remains largely unstudied, although early reports suggest that a low barrier to resistance will likely limit efficacy as primary therapy for patients with refractory or resistant disease. The investigational agent maribavir has shown promise as preemptive treatment; in patients with refractory or resistant disease the emergence of resistance while on treatment has been observed and ongoing studies will define efficacy in this population. Both agents have unique mechanisms of action limiting cross resistance, and neither exhibit myelotoxicity or nephrotoxicity.

Association of Donor and Recipient Cytomegalovirus Serostatus on Graft and Patient Survival in Liver Transplant Recipients.

Among solid organ transplant recipients, donor cytomegalovirus (CMV) seropositive (D+) and recipient seronegative (R-) status are associated with an increased risk of graft loss and mortality after kidney or lung transplantation. Whether a similar relationship exists among liver transplant recipients (LTR) is unknown. We assessed graft loss and mortality among adult LTRs from January 1, 2010, to March 14, 2020, in the Organ Procurement and Transplantation Network database. We used multivariable mixed Cox proportional hazards regression to analyze the association of donor and recipient CMV serostatus group with graft loss and mortality, with donor seronegative (D-) and recipient seronegative (R-) as the reference group. Among 54,078 LTRs, the proportion of D-R-, D- and recipient seropositive (R+), D+R-, and D+R+ was 13.4%, 22.5%, 22%, and 42%, respectively. By unadjusted Kaplan-Meier survival curve estimates, survival by the end of follow-up was 73.3%, 73.5%, 70.1%, and 69.7%, among the D-R-, D-R+, D+R-, and D+R+ groups, respectively. By multivariable Cox regression, the CMV D+R- serogroup, but not other serogroups, was independently associated with increased risks of graft loss (adjusted hazard ratio [aHR], 1.13; 95% confidence interval [CI], 1.05-1.22) and mortality (aHR, 1.13; 95% CI, 1.05-1.22). The magnitude of the association of the CMV D+R- serostatus group with mortality was similar when the Cox regression analysis was restricted to the first year after transplant and beyond the first year after transplant: aHR, 1.13 (95% CI, 1.01-1.27) and aHR, 1.13 (95% CI, 1.02-1.25), respectively. Even in an era of CMV preventive strategies, CMV D+R- serogroup status remains independently associated with increased graft loss and mortality in adult LTRs. Factors in addition to direct CMV-associated short-term mortality are likely, and studies to define the underlying mechanism(s) are warranted.

Current Understanding of Cytomegalovirus Reactivation in Critical Illness.

Cytomegalovirus (CMV) reactivation has been described in adults with critical illness caused by diverse etiologies, especially severe sepsis, and observational studies have linked CMV reactivation with worse clinical outcomes in this setting. In this study, we review observational clinical data linking development of CMV reactivation with worse outcomes in patients in the intensive care unit, discuss potential biologically plausible mechanisms for a causal association, and summarize results of initial interventional trials that examined the effects of CMV prevention. These data, taken together, highlight the need for a randomized, placebo-controlled efficacy trial (1) to definitively determine whether prevention of CMV reactivation improves clinical outcomes of patients with critical illness and (2) to define the underlying mechanism(s).

Reported ß-Lactam and Other Antibiotic Allergies in Solid Organ and Hematopoietic Cell Transplant Recipients.

BACKGROUND: Patients with reported ß-lactam antibiotic allergies (BLAs) are more likely to receive broad-spectrum antibiotics and experience adverse outcomes. Data describing antibiotic allergies among solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients are limited. METHODS: We reviewed records of adult SOT or allogeneic HCT recipients from 1 January 2013 to 31 December 2017 to characterize reported antibiotic allergies at time of transplantation. Inpatient antibiotic use was examined for 100 days posttransplant. Incidence rate ratios (IRRs) comparing antibiotic use in BLA and non-BLA groups were calculated using multivariable negative binomial models for 2 metrics: days of therapy (DOT) per 1000 inpatient days and percentage of antibiotic exposure-days. RESULTS: Among 2153 SOT (65%) and HCT (35%) recipients, 634 (29%) reported any antibiotic allergy and 347 (16%) reported BLAs. Inpatient antibiotics were administered to 2020 (94%) patients during the first 100 days posttransplantation; average antibiotic exposure was 41% of inpatient-days (interquartile range, 16.7%-62.5%). BLA patients had significantly higher DOT for vancomycin (IRR, 1.4 [95% confidence interval {CI}, 1.2-1.7]; P < .001), clindamycin (IRR, 7.6 [95% CI, 2.2-32.4]; P = .001), and aztreonam in HCT (IRR, 9.7 [95% CI, 3.3-35.0]; P < .001), and fluoroquinolones in SOT (IRR, 2.9 [95% CI, 2.1-4.0]; P < .001); these findings were consistent when using percentage of antibiotic exposure-days. CONCLUSIONS: Transplant recipients are frequently exposed to antibiotics and have a high prevalence of reported antibiotic allergies. Reported BLA was associated with greater use of ß-lactam antibiotic alternatives. Pretransplant antibiotic allergy evaluation may optimize antibiotic use in this population.

Impact of valganciclovir prophylaxis duration on cytomegalovirus disease in high-risk donor seropositive/recipient seronegative heart transplant recipients.

BACKGROUND: Few data support use of 6 over 3 months of antiviral prophylaxis for cytomegalovirus (CMV) disease prevention in donor seropositive/recipient seronegative (D+R-) heart transplant recipients (HTR). METHODS: We retrospectively assessed CMV disease and outcomes in 310 adult HTR between July 5, 2005, and December 30, 2016, at our center. Valganciclovir (VGCV) prophylaxis was given for 3-6 months in the D+R- group. Multivariable models evaluated risk factors for CMV disease in patients who received 3 vs 6 months (±1 month) of prophylaxis, with investigation of inverse probability weighting to correct for confounding variables. RESULTS: The incidence of CMV disease among all patients and the D+R- group was 8.7% (27/310) and 26.5% (22/83), respectively, and included syndrome in 22.2% (6/27) and end-organ involvement in 77.8% (21/27). In a multivariable model, 6 vs 3 months of antiviral prophylaxis was not associated with reduced risk for CMV disease (OR 2.28 [95% CI 0.66, 7.91], P = .19). CMV disease in D+R- HTR was associated with higher rates of hospitalization (87.5% [14/16] vs 6.3% [1/16], P < .001) and for a longer duration than in matched D+R- controls without disease. CONCLUSIONS: Cytomegalovirus disease remains a major cause of morbidity in D+R- HTR. In contrast to documented benefit in D+R- lung and kidney recipients, VGCV duration of 6 months was not associated with a lower incidence of CMV disease in D+R- HTR compared to 3-month duration and should be reconsidered in this patient population.

Clinical characteristics and outcomes of late-onset BK virus nephropathy in kidney and kidney-pancreas transplant recipients.

BACKGROUND: BK virus nephropathy (BKPyVAN) is a major complication in kidney transplant recipients (KTR) and typically occurs within 1 year of transplant. Guidelines vary in recommendations for BKPyV screening beyond 1 year. A systematic characterization of risk factors and outcomes of late-onset (>1 year) BKPyVAN has not previously been reported. METHODS: We retrospectively compared characteristics and outcomes of early- (<1 year) and late-onset BKPyVAN (definitive [biopsy-confirmed] or presumptive [plasma BKPyV >10 000 copies/mL]) in a cohort of 671 KTR and simultaneous kidney-pancreas transplant (SPK) recipients between 2008 and 2013 at a single US transplant center. Proportions were compared using Chi-square or Fisher's exact test with P < .05 considered significant. RESULTS: BKPyVAN was diagnosed in 96 (14.3%) patients (proven 16.7%, presumptive 83.3%): 79 (82.3%) early- and 17 (17.7%) late-onset. The proportion with late-onset BKPyVAN was significantly higher among SPK than KTR (4 of 7 [57.1%] vs 13 of 89 [14.6%], P = .017). Late-onset represented "de novo" infection (no BKPyV detection within the first year) in 14 (82.4%) and progression of earlier lower grade BKPyV reactivation in 3 (17.6%). Clinical outcomes were similar for early- and late-onset BKPyVAN (P > .05 all comparisons). In a pooled analysis of prior studies of BKPyVAN in SPK recipients, 62.9% (17 of 27) were late-onset. CONCLUSION: A significant proportion of BKPyVAN is late-onset, especially among SPK recipients, and supports a longer duration of BKPyV monitoring for SPK recipients than recommended in some guidelines.

Antimicrobial Stewardship in Immunocompromised Patients: Current State and Future Opportunities.

Immunocompromised (IC) patients are high risk for complications due to a high rate of antibiotic exposure. Antimicrobial stewardship interventions targeted to IC patients can be challenging due to limited data in this population and a high risk of severe infection-related outcomes. Here, the authors review immunocompromised antimicrobial stewardship barriers, metrics, and opportunities for antimicrobial use and testing optimization. Last, the authors highlight future steps in the field.

Shorter antibiotic courses in the immunocompromised: the impossible dream?

BACKGROUND: A growing number of studies have demonstrated similar outcomes with shorter courses of antibiotics for bacterial infections. Immunocompromised patients are frequently excluded from these studies despite anticipated benefits associated with shortening antibiotic courses (including lower risks of antibiotic toxicity, Clostridioides difficile infection, drug-resistant pathogens, and microbiome alterations). OBJECTIVES: To critically review the literature that assesses shorter antibiotic courses in immunocompromised patients, specifically among solid organ transplant recipients and neutropenic fever (NF) syndromes among patients on antineoplastic chemotherapy and undergoing haematopoietic cell transplant. SOURCES: References were identified through searches of PubMed, Embase, MEDLINE, and clinical guidelines documents. CONTENT: Among organ transplant recipients, the majority of studies assessing outcomes associated with shorter antibiotic courses have been retrospective but have demonstrated similar rates of clinically relevant endpoints. Patients with high- and low-risk NF have been well-studied, including enrolment in randomized studies, albeit with heterogeneous patient populations and outcomes assessed. Clinical improvement-guided adoption of shorter courses has been associated with fewer antibiotic days and similar rates of fever recurrence and mortality. IMPLICATIONS: Similar to studies demonstrating efficacy in immunocompetent patients, shorter antibiotic courses should be considered for immunocompromised hosts with presumed bacterial infections. Organ recipients and patients with NF syndromes should be prioritized for study in randomized controlled clinical trials assessing shorter course therapy.

Positivity of repeat nasal MRSA PCR screening: a single-center experience.

Repeating nasal methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reactions (PCRs) within 14 days may increase healthcare costs and inform anti-MRSA antibiotic therapy without known benefit. Within an inpatient admission, our retrospective, single-center evaluation found that conversion from negative to positive on repeat nasal MRSA PCR screen was uncommon (2%).

Increasing Proportion of High-risk Cytomegalovirus Donor-positive/Recipient-negative Serostatus in Solid Organ Transplant Recipients.

BACKGROUND: Cytomegalovirus (CMV) donor-positive/recipient-negative (D+R-) serostatus is independently associated with worse allograft and patient survival across solid organ transplant (SOT) types. We characterized trends in CMV D+R- serostatus among adult SOT recipients performed in the United States. METHODS: Donor (D) and recipient (R) CMV serostatus and demographic factors were obtained from the Scientific Registry of Transplant Recipients for persons ≥18 y undergoing a first SOT between January 1, 2000, and December 31, 2020. The proportions of D+R- SOTs over time were assessed using Chi square for trend and modeled through 2040. Factors associated with D/R seropositivity were assessed using logistic models. RESULTS: Among 472 549 SOTs, the average proportion of D+R- SOTs increased significantly among kidney, liver, heart, and lung between 2000 to 2009 and 2010 to 2020: 18.0% to 18.3% ( P = 0.034), 19.4% to 21.8% ( P < 0.001), 22.2% to 25.5% ( P < 0.001), and 23.6% to 27.0% ( P < 0.001), respectively. The increased proportion over time resulted from a disproportionate increase in R- (34.9% to 37.0% for all organ types, P < 0.001) and a smaller corresponding change in D+ (60.8% to 60.3%, P < 0.001). CONCLUSIONS: The proportion of high-risk CMV D+R- SOTs increased significantly across all organs and is projected to continue to increase. These findings inform population-level strategies to mitigate the negative impact of CMV D+R- in SOT.

BK Viremia and Changes in Estimated Glomerular Filtration Rate in Children and Young Adults after Hematopoietic Cell Transplantation.

Kidney disease in allogeneic hematopoietic cell transplantation (HCT) recipients is associated with increased mortality rates. BK virus (BKV) viremia has been associated with kidney dysfunction in pediatric HCT recipients; however, few studies have investigated longer-term kidney outcomes in association with BKV in this population. Here we assessed the relationship between BK viremia and changes in estimated glomerular filtration rate (eGFR) in children in the first year post-HCT. We selected 136 patients age ≤26 years who underwent HCT in 2007 to 2018 at a single center and had plasma BK viral load data available at 2 time points, weeks 4 to 7 post-HCT and weeks 10 to 13 post-HCT from prospectively collected stored plasma samples. A total of 272 samples were analyzed for BKV using quantitative PCR. We used multivariate linear models to determine the association of BK viremia and change in eGFR by 1 year post-HCT. Forty percent of the patients (54 of 136) had BKV detection in weeks 4 to 7, 13% of whom (7 of 54) had a BK viral load of ≥10,000 copies/mL, and 46% (62 of 136) had BKV detected in weeks 10 to 13, 34% (21 of 62) of whom had a BK viral load of ≥10,000 copies/mL. The mean decline in eGFR was 25.73 mL/min/1.73 m2 by 1 year post-HCT. In multivariate models, a BK viral load of ≥10,000 copies/mL during weeks 4 to 7 was associated with a mean decline in eGFR of 30.6 mL/min/1.73 m2 (95% confidence interval, -55.94 to -5.17; P = .019) compared with a BK viral load <10,000 copies/mL. In adjusted analyses, a high BK viral load in the blood (≥10,000 copies/mL) was associated with a significant decline in eGFR by 1 year post-HCT.

Comparison of Short-Term Outcomes in Kidney Transplant Recipients from SARS-CoV-2-Infected versus Noninfected Deceased Donors.

BACKGROUND: Acceptable post-transplant outcomes were reported in kidney transplant recipients from donors with coronavirus disease 2019 (COVID-19); however, there are no comparative studies with well-matched controls. METHODS: This multicenter, prospective observational study, which included three transplant centers in the United States, enrolled 61 kidney recipients from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected deceased donors. Using optimal matching methods, we matched every recipient to three comparators receiving kidneys from SARS-CoV-2-negative deceased donors with otherwise highly similar characteristics in the same transplant centers to compare 6-month eGFR. RESULTS: Among recipients of SARS-CoV-2-infected donor kidneys, one recipient died with a functional graft within 6 months. Mean 6-month eGFR was not significantly different between SARS-CoV-2-infected and noninfected donor groups (55±21 and 57±25 ml/min per 1.73 m 2 , respectively; P = 0.61). Six-month eGFR in recipients from SARS-CoV-2-infected donors who died of reasons other than COVID-19 was not significantly different from those from SARS-CoV-2-negative donors (58±22 and 56±25 ml/min per 1.73 m 2 , respectively; P = 0.51). However, recipients from donors who died of COVID-19 had significantly lower 6-month eGFR than those from SARS-CoV-2-negative donors (46±17 and 58±27 ml/min per 1.73 m 2 , respectively; P = 0.03). No donor-to-recipient SARS-CoV-2 transmission was observed. CONCLUSIONS: Six-month eGFR was not significantly different between recipients of kidneys from SARS-CoV-2-infected and noninfected donors. However, those receiving kidneys from donors who died of COVID-19 had significantly lower 6-month eGFR. Donor-to-recipient SARS-CoV-2 transmission was not observed.