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.

When antimicrobial stewardship begins with microbiological test requests: the case of asymptomatic bacteriuria.

PURPOSE OF REVIEW: We aim to review the rationale, methods, and experiences with diagnostic stewardship targeted at urinary tract infection (UTI) and related urinary syndromes. RECENT FINDINGS: In the last 18 months, several articles have demonstrated the impact of diagnostic stewardship interventions at limiting inappropriate diagnosis of UTIs or inappropriate antibiotic-prescribing, targeting the urinary tract. Antimicrobial stewardship programs may create and implement interventions at the point of urine test ordering, urine test resulting, or at the point of prescribing antibiotics after results have returned. Specific design and implementation of stewardship interventions depends on context. To maximize their impact, interventions should be accompanied by education and garner buy-in from providers. SUMMARY: Diagnostic stewardship can decrease unnecessary antibiotics and inappropriate diagnosis of UTI with multifaceted interventions most likely to be effective. Remaining questions include how to reduce ASB treatment in new populations, such as those with immune compromise, and persistent unknowns regarding UTI diagnosis and diagnostics.

A randomized, placebo-controlled, dose-escalation phase I/II multicenter trial of low-dose cidofovir for BK polyomavirus nephropathy.

BACKGROUND: BK polyomavirus-associated nephropathy (BKPyVAN) is an important cause of allograft dysfunction and failure in kidney transplant recipients (KTRs) and there are no proven effective treatments. Case reports and in vitro data support the potential activity of cidofovir against BK polyomavirus (BKPyV). METHODS: We report the results of a phase I/II, double-blind, placebo-controlled randomized dose-escalation trial of cidofovir in KTRs with biopsy-confirmed BKPyVAN and estimated glomerular filtration rate ≥30 mL/min. Intravenous cidofovir (0.25 mg/kg/dose or 0.5 mg/kg/dose) or placebo was administered on days 0, 7, 21, and 35, with final follow-up through day 49. RESULTS: The trial was prematurely discontinued due to slow accrual after 22 KTRs had completed the study. Cidofovir was safe and tolerated at the doses and duration studied. The proportion of subjects with any adverse event (AE) was similar between groups (9/14 [64%] in the combined cidofovir dose groups and 6/8 [75%] in the placebo group); 84% of AEs were mild. BKPyV DNAemia reduction by day 49 was similar between groups (>1 log10 reduction in (2/9 [22.2%] of 0.25 mg/kg group, 1/5 [20%] of 0.5 mg/kg group, and 2/8 [25%] of placebo group). CONCLUSIONS: These preliminary results indicate that low-dose cidofovir was safe and tolerated but had no significant BKPyV-specific antiviral effect in KTRs with BKPyVAN.

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.

Deceased Organ Donor HTLV Screening Practices Postelimination of Universal Screening in the United States.

Background: In the United States, universal screening for human T-lymphotropic virus (HTLV) in deceased organ donors was discontinued in 2009. Since then, the transplant guideline suggests considering targeted screening. However, the outcomes of this change in HTLV screening have not been evaluated. Methods: Using the Organ Procurement and Transplantation Network database between 2010 and 2022, we analyzed the HTLV antibody screening frequency and seroprevalence in potential deceased organ donors and their correlations with HTLV infection risks, including race and high-risk behaviors for blood-borne pathogen infection. Although targeted screening has not been established for HTLV, we hypothesized that screening rates should correlate with the proportions of donors with infection risk if screening is targeted. We also evaluated the organ utilization of HTLV-seropositive donors. Results: Of 130 284 potential organ donors, 22 032 (16.9%) were tested for HTLV antibody. The proportion of donors tested for HTLV varied between Organ Procurement Organizations (median [interquartile range], 3.8% [1.0%-23.2%]; range, 0.2%-99.4%) and was not correlated to HTLV infection risks. There were 48 seropositive donors (0.22%), and at least 1 organ from 42 of these donors (87.5%) was transplanted. The number of organs recovered and transplanted per donor was significantly lower in HTLV-seropositive than in HTLV-negative donors (recovered, 2 [2-3] versus 3 [3-5], P < 0.001; transplanted, 2 [1-3] versus 3 [2-4], P < 0.001). However, HTLV-1 infection was not attributed as the cause of nonrecovery except for only 1 HTLV-seropositive donor. Conclusions: HTLV screening practices varied across the United States. Our findings suggest that targeted screening was not performed after the elimination of universal screening.

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%).