Infections in Patients with Acute Leukemia. In: Maschmeyer G, Rolston KV, editors. Infections in Hematology. Berlin: Springer Berlin Heidelberg; 2015. pp. 3-23. [DOI: 10.1007/978-3-662-44000-1_1]

Optimizing antimicrobial prophylaxis strategies in acute leukemia patients: Assessing the efficacy of fluconazole

BACKGROUND

Acute myeloid (AML) and promyelocytic (APL) leukemia patients are at high risk for infection and mortality. While guidance for infection prevention is provided by the National Comprehensive Cancer Network (NCCN) and the American Society of Clinical Oncology (ASCO), each institution may vary in antimicrobial prophylaxis prescribing practices. The discrepancy may be explained by medication intolerance, cost, and low incidence of mold infections in leukemia patients. A recent meta-analysis demonstrated mortality benefits with the use of posaconazole, which was adopted by the NCCN. Despite known risks, it is unclear whether universal mold-active coverage is indicated for all AML and APL patients.

OBJECTIVE

To assess the incidence of breakthrough infections in AML and APL patients.

METHODS

This was a single-center, retrospective chart review of AML and APL patients receiving induction therapy at Baylor St Luke's Medical Center (BSLMC) between January 2019 and October 2021. The primary outcome assessed the incidence of breakthrough infections. Descriptive statistics were used to summarize the data.

RESULTS

A total of 55 patients were included and 54 (98%) had prolonged neutropenia with a median duration of 30 days. Five patients (9.3%) experienced breakthrough infections during induction while 21 individuals (38.9%) during the follow-up period. Aspergillus infections occurred in three patients receiving nonmold coverage compared to none on mold-active agents (p = 1.0) with no statistical difference in mortality.

CONCLUSION

Despite the majority of patients not receiving mold-active prophylaxis, nonmold-active prophylaxis may be sufficient with consideration of low aspergillosis incidence.

Mixed Clinical Pictures of Endogenous Endophthalmitis in a Relapse Leukemic Patient

Endogenous endophthalmitis is rare but sight-threatening in leukemic patients, which can have devastating sequelae. We report a case of a 15-year-old teenager with acute myeloid leukemia on relapse, presented with a mixed picture of endogenous endophthalmitis. The diagnosis dilemma in this patient proved difficult as Investigations and management can be challenging as young teenagers are usually less cooperative than adults. Endogenous endophthalmitis is not uncommon in this group of patients; however, mixed clinical pictures are almost unheard of, and the final diagnosis can be misleading if not treated accordingly. Viral infections such as cytomegalovirus (CMV), bacterial, and fungal are all considered potential opportunistic infections. Diagnosis of endogenous endophthalmitis is complex and relies heavily on the clinical characteristics of each organism supported by intravitreal tapping and culture samples. However, data from endogenous endophthalmitis in leukemic patients is scarce nowadays across the board. In this case report, we highlight the challenges of managing endogenous endophthalmitis in a young leukemic patient due for bone marrow transplantation. Future studies are needed to investigate the current microorganism trends and treatments available. An algorithm for managing endophthalmitis in immunosuppressed patients should be done to provide a better approach from the get-go.

Contribution of the Oral and Gastrointestinal Microbiomes to Bloodstream Infections in Leukemia Patients

Bloodstream infections (BSIs) pose a significant mortality risk for acute myeloid leukemia (AML) patients. It has been previously reported that intestinal domination (>30% relative abundance [RA] attributed to a single taxon) with the infecting taxa often precedes BSI in stem cell transplant patients. Using 16S rRNA amplicon sequencing, we analyzed oral and stool samples from 63 AML patients with BSIs to determine the correlation between the infectious agent and microbiome composition. Whole-genome sequencing and antimicrobial susceptibilities were performed on all BSI isolates. Species-level detection of the infectious agent and presence of antibiotic resistance determinants in the stool (blaCTX-M-15, blaCTX-M-14, cfrA, and vanA) were confirmed via digital droplet PCR (ddPCR). Individuals with Escherichia coli (stool P < 0.001), Pseudomonas aeruginosa (oral P = 0.004, stool P < 0.001), and viridans group streptococci (VGS) (oral P = 0.001) bacteremia had a significantly higher relative abundance of those respective genera than other BSI patients, which appeared to be site specific. Although 78% of patients showed presence of the infectious genera in the stool and/or saliva, only 7 exhibited microbiome domination. ddPCR confirmed species specificity of the 16S data and detected the antibiotic resistance determinants found in the BSI isolates within concurrent stools. Although gastrointestinal (GI) domination by an infecting organism was not present at the time of most BSIs in AML, the pathogens, along with AMR elements, were detectable in the majority of patients. Thus, rapid genetic assessment of oral and stool samples for the presence of potential pathogens and AMR determinants might inform personalized therapeutic approaches in immunocompromised patients with suspected infection. IMPORTANCE A major cause of mortality in hematologic malignancy patients is BSI. Previous studies have demonstrated that bacterial translocation from the GI microbiome is a major source of BSIs and is often preceded by increased levels of the infectious taxa in the GI (>30% abundance by 16S rRNA sequencing). In this study, we sought to better understand how domination and abundance levels of the oral and gut microbiome relate to bacteremia occurrence in acute myeloid leukemia patients. We conclude that analyses of both oral and stool samples can help identify BSI and antimicrobial resistance determinants, thus potentially improving the timing and tailoring of antibiotic treatment strategies for high-risk patients.

Dermatologic complications in transplantation and cellular therapy for acute leukemia

Adoptive cellular immunotherapy, mainly hematopoietic stem cell transplant and CAR-T cell therapy have revolutionized treatment of patients with acute leukemia. Indications and inclusion criteria for these treatments have expanded in recent years. While these therapies are associated with significant improvements in disease response and overall survival, patients may experience adverse events from associated chemotherapy conditioning, engraftment, cytokine storm, supportive medications, and post-transplant maintenance targeted therapies. Supportive oncodermatology is a growing specialty to manage cutaneous toxicities resulting from the anti-cancer therapies. In this review, we summarize diagnosis and management of the common cutaneous adverse events including drug eruptions, graft-versus-host disease, neoplastic and paraneoplastic complications in patients undergoing cellular therapies.

Management of febrile neutropenia in the perspective of antimicrobial de-escalation and discontinuation

Introduction: Infections are among the most frequent complications in patients with hematological and oncological diseases. They might be classified as fever of unknown origin and microbiologically or clinically documented infections. Optimal duration of antimicrobial treatment is still unclear in these patients.Areas covered: We provide an overview on the management of febrile neutropenia in the perspective of antimicrobial de-escalation and discontinuation.Expert opinion: Patients with febrile high-risk neutropenia should be treated empirically with an anti-pseudomonal agent such as piperacillin/tazobactam. Several clinical studies support the assumption that the primary antibiotic regimen might be safely discontinued prior to neutrophil reconstitution if the patient is afebrile for several days and all infection-related symptoms have been resolved. Primary empirical treatment with carbapenems or antibiotic combinations should commonly only be considered in selected patient subgroups, such as patients with severe neutropenic sepsis or colonization with multidrug-resistant bacteria. Preemptive antifungal treatment guided by lung imaging and other parameters (e.g. serial Aspergillus galactomannan antigen screening) might reduce the consumption of antifungals compared to the classical empirical approach.Multidrug-resistant pathogens are emerging, and novel anti-infective agents under development are scarce. Therefore, a rational use of antimicrobials based on the principles of antibiotic stewardship is crucial.