Incidence and Impact of Fungal Infections in Post-Transplantation Cyclophosphamide-Based Graft-versus-Host Disease Prophylaxis and Haploidentical Hematopoietic Cell Transplantation: A Center for International Blood and Marrow Transplant Research Analysis

Fungal infection (FI) after allogeneic hematopoietic cell transplantation (HCT) is associated with increased morbidity and mortality. Neutropenia, HLA mismatch, graft-versus-host disease (GVHD), and viral infections are risk factors for FI. The objectives of this Center for International Blood and Marrow Transplant Research registry study were to compare the incidence and density of FI occurring within 180 days after HCT in matched sibling (Sib) transplants with either calcineurin inhibitor (CNI)-based or post-transplantation cyclophosphamide (PTCy)-based GVHD prophylaxis and related haploidentical transplants receiving PTCy, and to examine the impact of FI by day 180 on transplantation outcomes.

METHODS

Patients who underwent their first HCT between 2012 and 2017 for acute myeloid leukemia, acute lymphoblastic leukemia, and myelodysplastic syndrome and received a related haploidentical transplant with PTCy (HaploCy; n = 757) or a Sib transplant with PTCy (SibCy; n = 403) or CNI (SibCNI; n = 1605) were analyzed. The incidence of FI by day 180 post-HCT was calculated as cumulative incidence with death as the competing risk. The associations of FI with overall survival, transplant-related mortality, chronic GVHD, and relapse at 2 years post-HCT were examined in Cox proportional hazards regression models. Factors significantly associated with the outcome variable at a 1% level were kept in the final model.

RESULTS

By day 180 post-HCT, 56 (7%) HaploCy, 24 (6%), SibCy, and 59 (4%) SibCNI recipients developed ≥1 FI (P < .001). The cumulative incidence of yeast FI was 5.2% (99% confidence interval [CI], 3.3% to 7.3%) for HaploCy, 2.2% (99% CI, .7% to 4.5%) for SibCy, and 1.9% (99% CI, 1.1% to 2.9%) for SibCNI (P = .001), and that of mold FI was 2.9% (99% CI, 1.5% to 4.7%), 3.7% (99% CI, 91.7% to 6.6%), and 1.7% (99% CI, 1.0% to 2.6%), respectively (P = .040). FI was associated with an increased risk of death, with an adjusted hazard ratio (HR) of 4.06 (99% CI, 2.2 to 7.6) for HaploCy, 4.7 (99% CI, 2.0 to 11.0) for SibCy, and 3.4 (99% CI, 1.8 to 6.4) for SibCNI compared with SibCNI without FI (P < .0001 for all). Similar associations were noted for transplantation-related mortality. FI did not impact rates of relapse or chronic GVHD.

CONCLUSIONS

Rates of FI by day 180 ranged between 1.9% and 5.2% for yeast FI and from 1.7% to 3.7% for mold FI across the 3 cohorts. The use of PTCy was associated with higher rates of yeast FI only in HaploHCT and with mold FI in both HaploHCT and SibHCT. The presence of FI by day 180 was associated with increased risk for overall mortality and transplant-related mortality at 2 years regardless of donor type or PTCy use. Although rates of FI were low with PTCy, FI is associated with an increased risk of death, underscoring the need for improved management strategies.

Bloodstream Infections in Hematologic Malignancy Patients with Fever and Neutropenia: Are Empirical Antibiotic Therapies in the United States Still Effective?

Background

Rising antimicrobial resistance rates may impact the efficacy of empirical antibiotic treatment for febrile neutropenia in high-risk cancer patients. Lacking contemporary data about the epidemiology, antibiotic resistance patterns, and clinical outcomes from bloodstream infections (BSI) in U.S. cancer patients, it is unclear if current guidelines remain relevant.

Methods

In a cross-sectional study, fourteen U.S. cancer centers prospectively identified BSIs in high-risk FN patients, including those receiving chemotherapy for hematologic malignancies or hematopoietic stem cell transplantation.

Results

Among 389 organsims causing BSI in 343 patients, there was an equal distribution of Gram-negative (GN) and Gram-positive (GP) bacteria, with variability across centers. Cefepime and piperacillin-tazobactam were the most commonly prescribed empirical antibiotics for FN, at 62% and 23% respectively; a GP-directed agent was empirically included in nearly half of all FN episodes within the first 24 hours. Susceptibility to fluoroquinolones, cefepime, piperacillin-tazobactam, and carbapenems was 49%, 84%, 88% and 96% respectively among GN isolates. Critical illness (CrI), defined as a new requirement for mechanical ventilation, vasopressor or death within 30 days, occurred in 15% and did not correlate with fluoroquinolone prophylaxis, organism type, initial antibiotics or adequacy of coverage. Only severity of illness at presentation, signified by a Pitt bacteremia score &gt; 2, predicted for critical illness within 30 days. Mortality was 4% by day 7 and 10% overall.

Conclusion

In accordance with U.S. guidelines, cefepime or piperacillin-tazobactam remain effective agents or empirical treatment for high risk cancer patients with FN who are stable at presentation, maintaining high GN pathogen susceptibility and yielding excellent outcomes.

Early E. casseliflavus gut colonization and outcomes of allogeneic hematopoietic cell transplantation

Gut dysbiosis has been associated with worse allogeneic hematopoietic cell transplantation (allo-HCT) outcomes. We reported an association between intrinsically vancomycin-resistant enterococci (iVRE: E. gallinarum and E. casseliflavus) gut colonization and lower post-transplant mortality. In this study, using an expanded cohort, we evaluated whether our previously observed association is species-specific. We included allo-HCT recipients with ≥1 positive rectal swab or stool culture for iVRE between days -14 and +14 of transplant. To investigate whether iVRE modulate the gut microbiota, we performed agar diffusion assays. To investigate whether iVRE differ in their ability to activate the aryl hydrocarbon receptor, we analyzed iVRE genomes for enzymes in the shikimate and tryptophan pathways. Sixty six (23 E. casseliflavus and 43 E. gallinarum) of the 908 allograft recipients (2011-2017) met our inclusion criteria. Overall survival was significantly higher in patients with E. casseliflavus (91% vs. 62% at 3 years, P = 0.04). In multivariable analysis, E. casseliflavus gut colonization was significantly associated with reduced all-cause mortality (hazard ratio 0.20, 95% confidence interval 0.04-0.91, P = 0.04). While agar assays were largely unremarkable, genome mining predicted that E. casseliflavus encodes a larger number of enzymes in the tryptophan metabolism pathway. In conclusion, E. casseliflavus gut colonization is associated with reduced post-HCT morality. Further research is needed to understand the mechanisms for this association.

Current practices for treatment of respiratory syncytial virus and other non-influenza respiratory viruses in high-risk patient populations: a survey of institutions in the Midwestern Respiratory Virus Collaborative

Background

The optimal treatment for respiratory syncytial virus (RSV) infection in adult immunocompromised patients is unknown. We assessed the management of RSV and other non‐influenza respiratory viruses in Midwestern transplant centers.

Methods

A survey assessing strategies for RSV and other non‐influenza respiratory viral infections was sent to 13 centers.

Results

Multiplex polymerase chain reaction assay was used for diagnosis in 11/12 centers. Eight of 12 centers used inhaled ribavirin (RBV) in some patient populations. Barriers included cost, safety, lack of evidence, and inconvenience. Six of 12 used intravenous immunoglobulin (IVIG), mostly in combination with RBV. Inhaled RBV was used more than oral, and in the post‐stem cell transplant population, patients with lower respiratory tract infection (LRTI), graft‐versus‐host disease, and more recent transplantation were treated at higher rates. Ten centers had experience with lung transplant patients; all used either oral or inhaled RBV for LRTI, 6/10 treated upper respiratory tract infection (URTI). No center treated non‐lung solid organ transplant (SOT) recipients with URTI; 7/11 would use oral or inhaled RBV in the same group with LRTI. Patients with hematologic malignancy without hematopoietic stem cell transplantation were treated with RBV at a similar frequency to non‐lung SOT recipients. Three of 12 centers, in severe cases, treated parainfluenza and metapneumovirus, and 1/12 treated coronavirus.

Conclusions

Treatment of RSV in immunocompromised patients varied greatly. While most centers treat LRTI, treatment of URTI was variable. No consensus was found regarding the use of oral versus inhaled RBV, or the use of IVIG. The presence of such heterogeneity demonstrates the need for further studies defining optimal treatment of RSV in immunocompromised hosts.

Hemorrhagic cystitis after allogeneic hematopoietic cell transplantation: risk factors, graft source and survival

Although hemorrhagic cystitis (HC) is a common complication of allogeneic hematopoietic cell transplantation (alloHCT), its risk factors and effects on survival are not well known. We evaluated HC in a large cohort (n=1321, 2003-2012) receiving alloHCT from all graft sources, including umbilical cord blood (UCB). We compared HC patients with non-HC (control) patients and examined clinical variables at HC onset and resolution. Of these 1321 patients, 219 (16.6%) developed HC at a median of 22 days after alloHCT. BK viruria was detected in 90% of 109 tested HC patients. Median duration of HC was 27 days. At the time of HC diagnosis, acute GVHD, fever, severe thrombocytopenia and steroid use were more frequent than at the time of HC resolution. In univariate analysis, male sex, age <20 years, myeloablative conditioning with cyclophosphamide and acute GVHD were associated with HC. In multivariate analysis, HC was significantly more common in males and HLA-mismatched UCB graft recipients. Severe grade HC (grade III-IV) was associated with increased treatment-related mortality but not with overall survival at 1 year. HC remains hazardous and therefore better prophylaxis, and early interventions to limit its severity are still needed.

Executive Summary: Clinical Practice Guideline for the Use of Antimicrobial Agents in Neutropenic Patients with Cancer: 2010 Update by the Infectious Diseases Society of America

This document updates and expands the initial Infectious Diseases Society of America (IDSA) Fever and Neutropenia Guideline that was published in 1997 and first updated in 2002. It is intended as a guide for the use of antimicrobial agents in managing patients with cancer who experience chemotherapy-induced fever and neutropenia.

Recent advances in antimicrobial drug development and technology, clinical trial results, and extensive clinical experience have informed the approaches and recommendations herein. Because the previous iteration of this guideline in 2002, we have a developed a clearer definition of which populations of patients with cancer may benefit most from antibiotic, antifungal, and antiviral prophylaxis. Furthermore, categorizing neutropenic patients as being at high risk or low risk for infection according to presenting signs and symptoms, underlying cancer, type of therapy, and medical comorbidities has become essential to the treatment algorithm. Risk stratification is a recommended starting point for managing patients with fever and neutropenia. In addition, earlier detection of invasive fungal infections has led to debate regarding optimal use of empirical or preemptive antifungal therapy, although algorithms are still evolving.

What has not changed is the indication for immediate empirical antibiotic therapy. It remains true that all patients who present with fever and neutropenia should be treated swiftly and broadly with antibiotics to treat both gram-positive and gram-negative pathogens.

Finally, we note that all Panel members are from institutions in the United States or Canada; thus, these guidelines were developed in the context of North American practices. Some recommendations may not be as applicable outside of North America, in areas where differences in available antibiotics, in the predominant pathogens, and/or in health care–associated economic conditions exist. Regardless of venue, clinical vigilance and immediate treatment are the universal keys to managing neutropenic patients with fever and/or infection.

Time trends in fungal infections as a cause of death in hematopoietic stem cell transplant recipients: an autopsy study

Infectious complications remain an important cause of death in hematopoietic stem cell transplant (HSCT) recipients. We undertook a 20-year (1988-2007) retrospective review of all autopsies performed on HSCT recipients in our institution, with emphasis on infections, especially fungal infections, as the cause of death. Of the 2,943 autopsies performed in our institution from 1988 to 2007, 395 (13.4%) involved HSCT recipients (117 pediatric; 278 adult). Of the patients, 298 had received allogeneic, 46 autologous, 41 umbilical cord blood, and 3 autologous plus allogeneic types, and 7 were unknown HSCT types. The most common causes of death were pulmonary complications, occurring in 247 (62.5%) of 395 cases. In 178 cases (45.1%), microorganisms (viral, bacterial, and/or fungal) were documented at autopsy in one or more organs and contributed to the cause of death. Fungal infections were found in 23.5% of cases, but their frequency as a cause of death decreased throughout this study, from 30.3% in the 1988-1992 period to 10.9% in the 2003-2007 period.