Allogeneic Transplant Recipients Research Articles

A phase 3 randomized, double-blind, comparator-controlled study to evaluate safety, tolerability and immunogenicity of V114, a 15-valent pneumococcal conjugate vaccine, in allogeneic hematopoietic cell transplant recipients (PNEU-STEM).

Individuals who receive allogeneic hematopoietic cell transplant (allo-HCT) are immunocompromised and at high risk for pneumococcal infections, especially in the months following transplant. This study evaluated the safety and immunogenicity of V114 (VAXNEUVANCE™), a 15-valent pneumococcal conjugate vaccine (PCV), when given to allo-HCT recipients. Participants received 3 doses of V114 or PCV13 in one-month intervals starting 3-6 months after allo-HCT. Twelve months after HCT, participants received either PNEUMOVAXTM 23 or a fourth dose of PCV (if they experienced chronic graft versus host disease). Safety was evaluated as the proportion of participants with adverse events (AEs). Immunogenicity was evaluated by measuring serotype-specific immunoglobulin G (IgG) geometric mean concentrations (GMCs) and opsonophagocytic activity (OPA) geometric mean titers (GMTs) for all V114 serotypes in each vaccination group. A total of 274 participants were enrolled and vaccinated in the study. The proportions of participants with AEs and serious AEs were generally comparable between intervention groups, and the majority of AEs in both groups were of short duration and mild-to-moderate intensity. For both IgG GMCs and OPA GMTs, V114 was generally comparable to PCV13 for the 13 shared serotypes, and higher for serotypes 22F and 33F at Day 90. V114 was well tolerated in allo-HCT recipients with a generally comparable safety profile to PCV13. V114 induced comparable immune responses to PCV13 for the 13 shared serotypes, and higher for V114 serotypes 22F and 33F. Study results support use of V114 in allo-HCT recipients.

Corticosteroids as graft-versus-host disease prophylaxis for allogeneic hematopoietic cell transplant recipients with calcineurin inhibitor intolerance

Background aimsAlthough calcineurin inhibitors (CNIs) have a well-established role in the prevention of graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT), their use can be limited by significant toxicities, which may result in premature treatment discontinuation. The optimal management of patients with CNI intolerance is unknown. The objective of this study was to determine the effectiveness of corticosteroids as GVHD prophylaxis for patients with CNI intolerance. MethodsThis retrospective single-center study included consecutive adult patients with hematologic malignancies who underwent myeloablative peripheral blood allogeneic HCT with anti-thymocyte globulin, CNI, and methotrexate GVHD prophylaxis in Alberta, Canada. Multivariable competing-risks regression was used to compare cumulative incidences of GVHD, relapse, and non-relapse mortality between recipients of corticosteroid versus continuous CNI prophylaxis, and multivariable Cox proportional hazards regression was applied to compare overall survival, relapse-free survival (RFS) and moderate-to-severe chronic GVHD and RFS. ResultsAmong 509 allogeneic HCT recipients, 58 (11%) patients developed CNI intolerance and were switched to corticosteroid prophylaxis at median 28 days (range 1-53) after HCT. Compared with patients who received continuous CNI prophylaxis, recipients of corticosteroid prophylaxis had significantly greater cumulative incidences of grade 2-4 acute GVHD (subhazard ratio [SHR] 1.74, 95% confidence interval [CI] 1.08–2.80, P = 0.024), grade 3–4 acute GVHD (SHR 3.22, 95% CI 1.55–6.72, P = 0.002), and GVHD-related non-relapse mortality (SHR 3.07, 95% CI 1.54–6.12, P = 0.001). There were no significant differences in moderate-to-severe chronic GVHD (SHR 0.84, 95% CI 0.43–1.63, P = 0.60) or relapse (SHR 0.92, 95% CI 0.53–1.62, P = 0.78), but corticosteroid prophylaxis was associated with significantly inferior overall survival (hazard ratio [HR] 1.77, 95% CI 1.20–2.61, P = 0.004), RFS (HR 1.54, 95% CI 1.06–2.25, P = 0.024), and chronic GVHD and RFS (HR 1.46, 95% CI 1.04–2.05, P = 0.029). ConclusionsAllogeneic HCT recipients with CNI intolerance are at increased risks of acute GVHD and poor outcomes despite institution of corticosteroid prophylaxis following premature CNI discontinuation. Alternative GVHD prophylaxis strategies are needed for this high-risk population.

Utilization of a Population Pharmacokinetic Model to Improve a Busulfan Test-Dose Strategy in Allogeneic Hematopoietic Cell Transplant Recipients.

Busulfan is an alkylating agent used as part of conditioning chemotherapy regimens prior to allogeneic hematopoietic cell transplant (allo-HCT). Pharmacokinetic (PK)-guided test-dose strategies have been shown to improve the number of patients achieving busulfan exposure goals and improve clinical outcomes. However, current practices require extensive PK sampling. In this study, PK data were retrospectively collected from busulfan drug monitoring records from adult allo-HCT recipients who received once-daily intravenous busulfan at the University of North Carolina Medical Center (UNCMC). A population pharmacokinetic (popPK) model was developed to identify sources of interindividual variability and evaluate alternative PK sampling strategies. A 2-compartment model, with covariate effects of actual body weight and sex, best described the data. The typical value of clearance for an 83kg male was estimated to be 11.21L/h. Fifty-nine percent of allo-HCT recipients were estimated to have met the UNCMC institutional myeloablative conditioning (MAC) exposure goal based on model post hoc estimates of clearance using all PK samples obtained following MAC dosing. Fifty-seven percent of patients were estimated to have met this goal based on post hoc estimates using a single PK sample. Our results indicate once-daily, intravenous busulfan PK in adult allo-HCT recipients receiving MAC dosing can be reasonably described by a popPK model, and the use of a sparse PK sampling strategy may be feasible for determining target exposure attainment following MAC dosing. Use of a popPK model and sparse PK sampling strategy to carry out busulfan test-dose procedures could reduce health care costs and inconvenience to patients.

Patient-reported patterns of follow-up care in the ‘Aftercare in Blood Cancer Survivors’ (ABC) study

BackgroundFollow-up care provides long-term support for cancer survivors. Little is known about follow-up care in hematologic malignancies.MethodsOur questionnaire-based study included blood cancer survivors diagnosed at the University Hospital of Essen before 2010, with a ≥ 3-year interval since the last intense treatment. The primary goal of the retrospective study was the identification and characterization of follow-up institutions.ResultsOf 2386 survivors meeting the inclusion criteria, 1551 (65.0%) consented to participate, with a follow-up duration > 10 years in 731. The university hospital provided care for 1045 participants (67.4%), non-university oncologists for 231 (14.9%), and non-oncological internists or general practitioners for 203 (13.1%). Seventy-two participants (4.6%) abstained from follow-up care. The disease spectrum differed among follow-up institutions (p < 0.0001). While allogeneic transplant recipients clustered at the university hospital, survivors with monoclonal gammopathy, multiple myeloma, myeloproliferative disorders, or indolent lymphomas were often seen by non-university oncologists, and survivors with a history of aggressive lymphoma or acute leukemia by non-oncological internists or general practitioners. Follow-up intervals mirrored published recommendations. Follow-up visits were dominated by conversations, physical examination, and blood tests. Imaging was more often performed outside than inside the university hospital. Satisfaction with follow-up care was high, and quality of life was similar in all follow-up institutions. A need for improvement was reported in psychosocial support and information about late effects.ConclusionsThe naturally evolved patterns identified in the study resemble published care models: Follow-up clinics for complex needs, specialist-led care for unstable disease states, and general practitioner-led care for stable conditions.

Demographic comparison of survival outcomes after bone marrow transplantation in adolescent and young adult patients: A single institution cohort study.

e18522 Background: Bone marrow transplant (BMT) has become an increasingly common treatment modality for both malignant and non-malignant conditions. However, BMT requires significant healthcare and financial resources, which can result in allocation disparities across socioeconomic, demographic, and racial/ethnic groups. The data exploring how demographic disparities impact survival after BMT is limited, particularly within the adolescent and young adult (AYA) population, defined as patients between the ages of 15 and 39 years. The goal of this study was to assess overall survival of AYA patients undergoing transplant at our institution and to gain insight into if demographic factors impact the likelihood of mortality after transplantation. Methods: Patients aged 15-39 who underwent transplant at the Wilmot Cancer Institute in Rochester, NY between 2012-2020 were identified. Information regarding demographic characteristics, indication for transplant, and mortality was collected. The primary endpoint was overall survival (OS), defined as the time from transplant to the date of death from any cause or the date of last in-person contact. Survival criteria were estimated using the Kaplan-Meier method and compared using mortality odds ratios. These analyses were stratified by indication for transplant, recorded race/ethnicity, gender, and by age. Results: 169 patients met inclusion criteria, and median OS for the entire cohort was not reached. Of 108 allogenic transplant recipients, median OS was 7.85 years (95% CI [3.3, not estimated]). Median OS for patients receiving transplant for solid tumor pathology was 3 years (95% CI [0.4 years, not estimated]), compared to other indications for transplant where survival exceeded the median. For allogenic transplant patients, median OS for Black patients was 4.8 years (95% CI [0.7 years, not estimated]), 7.8 years for Caucasian patients (95% CI [3.3 years, not estimated]), median OS was not reached for Hispanic patients, and 1.1 years for all other minorities (95% CI [0.4 years, not estimated]) (p = 0.28). There was no significant difference in mortality based on insurance type or gender for either type of transplant. There was a significant difference in mortality for allogenic transplant patients based on average median household income when compared at an average income of $60,000/ year (OR 2.6, 95% CI [1.164, 5.6] p = 0.0097). Conclusions: Overall survival for AYA patients who had a transplant for any indication at our institution was better than expected. There were no significant differences for either transplant type based on gender, racial/ethnic background, gender, age, or indication for transplant. There was a significant difference based on median household income. Larger multi-institutional studies are likely needed to accurately identify further demographic disparities.

A retrospective analysis on mucormycosis in patients with hematological diseases: a single center experience from Turkey

Aim: Mucormycosis is an acute, invasive, devastating and highly fatal fungal infection, affecting particularly immunocompromised patients; fortunately, it is rare. This study aimed to describe the attitude of mucormycosis in patients with a hematological disease, and to evaluate the risk factors associated with mortality.&#x0D; Material and Method: We retrospectively assessed the demographic and clinical data of patients who were diagnosed with mucormycosis in Erciyes University Hematology and Bone Marrow Transplantation Center, between 2010 and 2020. The study was included 34 patients with a history of either hematological malignancy or hematopoietic stem cell transplantation. &#x0D; Results: Twenty-seven patients had proven infection, and the others had possible infection. The most frequent underlying disease was acute leukemia. Seven-teen patients had a history of allogeneic transplantation, and frequency of mucormycosis was 3.5% among allogeneic transplant recipients. The most frequent site of infection was the rhino-orbital region (85.3%). Forty-seven percent of patients presented with acute orbital symptoms. Fifteen patients were on a mucor-active antifungal (posaconazole and liposomal Amphotericin B) prophylaxis or treatment at the time of diagnosis. All patients received liposomal Amphotericin B and seven patients received posaconazole additionally as initial therapy. Surgical debridement was performed in 91.1% of patients. The two-year mucor-related mortality rate was 44.1%. The survival curves were significantly lower in patients with concomitant fungal pneumonia, allogeneic transplantation and also in patients who were receiving mucor-active antifungal drugs at the time of diagnosis.&#x0D; Conclusion: Mucormycosis remains a significant problem for hematology clinicians despite the expanding use of antifungal prophylaxis. Moreover, breakthrough infections indicate rising danger regarding resistant agents. We also highlight that, most of the patients receiving broad-spectrum antifungal prophylaxis are more fragile and more complicated patients, which put them at increased baseline risk for mucormycosis, and deserve more attention.

Invasive Mold Infections in Children: Navigating Troubled Waters with a Broken Compass.

Incidence of invasive mold infections in children, while rare, is increasing as the population of high-risk patients expands, including premature infants, pediatric patients undergoing treatment for hematological malignancies, or recipients of allogeneic hematologic stem cell transplants. The infectious agents, including Aspergillus spp., Mucorales, and other molds, are especially difficult to treat and have serious morbidity and high mortality. Clinicians must maintain a high index of suspicion for invasive mold infections in at-risk patients. Diagnosis of invasive mold infections is complicated by difficulties isolating pathogens on culture, but progress is being made in immunological and molecular diagnostic technologies. Treatment in children is challenging; no randomized controlled trials exist. There is a growing body of data on treatment, specifically on safer antifungal agents, including indications for treatment, spectrum of coverage, pharmacokinetics for different ages, and pharmacodynamic targets associated with therapeutic success. However, pediatricians must often extrapolate from adult data. In this review, we aim to harmonize the existing body of literature on invasive mold infections in children, covering epidemiology, clinical presentations, diagnostic methods, and principles of management.

Immunosuppressant adherence in adult outpatient hematopoietic cell transplant recipients.

Medication nonadherence continues to be challenging for allogeneic hematopoietic cell transplant (HCT) recipients. The risk and severity of chronic graft-versus-host disease (GVHD) are associated with low immunosuppressant concentrations (which can be improved with model-informed precision dosing (MIPD)) and with immunosuppressant nonadherence (which can be improved with acceptable interventions). With the goals of improving adherence and achieving therapeutic concentrations of immunosuppressants to eliminate GVHD, we characterized the feasibility of using the Medication Event Monitoring (MEMS®) Cap in adult HCT recipients. Of the 27 participants offered the MEMS® Cap at the time of hospital discharge, 7 (25.9%) used it, which is below our a priori threshold of 70%. These data suggest the MEMS® Cap is not feasible for HCT recipients. The MEMS® Cap data were available for a median of 35 days per participant per medication (range: 7-109 days). The average daily adherence per participant ranged from 0 to 100%; four participants had an average daily adherence of over 80%. MIPD may be supported by MEMS® technology to provide the precise time of immunosuppressant self-administration. The MEMS® Cap was used by only a small percentage (25.9%) of HCT recipients in this pilot study. In accordance with larger studies using less accurate tools to evaluate adherence, immunosuppressant adherence varied from 0% to 100%. Future studies should establish the feasibility and clinical benefit of combining MIPD with newer technology, specifically the MEMS® Button, which can inform the oncology pharmacist of the time of immunosuppressant self-administration.

Prohibitin is Upregulated on Donor T cells in Murine Acute Graft-versus-Host Disease and Promotes Th17 Response

Abstract Introduction: Acute graft-versus-host disease (GVHD) is a T cell-mediated disorder and the main cause of non-relapse mortality in allogeneic hematopoietic cell transplantation recipients. Here, we investigate PHB in Th17-mediated inflammation and as a therapeutic target for acute GVHD. Methods: Irradiated mice received T cell depleted bone marrow cells and allogeneic or syngeneic splenocytes. At day 25 post-transplant, blood, spleen, liver, and colon were harvested and analyzed for surface PHB, IFNγ, and IL-17 on donor T cells by flow cytometry. Splenocytes were cultured in the presence of PHB pharmacological inhibitor rocaglamide (RocA) and analyzed for PHB and IL-17 expression in donor T cells. Naïve murine CD4 T cells were cultured in Th17 polarizing conditions with RocA. CRISPR/Cas9-mediated knockout of PHB was performed followed by evaluation of Il17a, Il17f, and Il22 gene expression by quantitative PCR. Results: Surface expression of PHB is increased in murine allogeneic donor T cells in liver, spleen, colon, and peripheral blood in acute GVHD. PHB-expressing splenic T cells secrete IL-17, which is reduced with treatment with a PHB inhibitor in ex vivo experiments. PHB inhibition of murine CD4 T cells in vitro impairs differentiation into the Th17 subtype resulting in reduced IL-17 secretion and downregulation of Il17a, Il17f, and Il22 genes. Knockout of PHB reduces transcription of Il17 and Il22 genes. Conclusions: These findings show relevancy of PHB in Th17-mediated inflammation and suggest a potential role for PHB in acute GVHD. To our knowledge, this study is the first to investigate PHB in acute GVHD, and our findings will offer greater support for clinical use of PHB inhibition to treat this fatal disease. Supported by grants from AAI (KS, PR), ACS (PR; RSG-22-053-01-IBCD), and NIH NCI (PR; R01 CA252469).

Acute kidney injury in an allogeneic hematopoietic cell transplant recipient: Answers.

Acute kidney injury in an allogeneic hematopoietic cell transplant recipient: Answers.

Acute kidney injury in an allogeneic hematopoietic cell transplant recipient: Questions.

Acute kidney injury in an allogeneic hematopoietic cell transplant recipient: Questions.

Clinical characteristics and risk factors of pneumococcal diseases in recipients of allogeneic hematopoietic stem cell transplants in the late phase: A retrospective registry study

Pneumococcal diseases are one of the most important infectious complications in the late period following allogeneic hematopoietic stem cell transplantation (allo-HSCT). The importance of long-term follow-up care is increasing, as the number of long-term survivors following allo-HSCT increases, but there has been a dearth of research specifically focusing on pneumococcal diseases during the late post-transplant period (day >100). Using a transplant registry database between January 1, 2001 and December 31, 2011, we aimed to assess the clinical spectrum and risk factors for pneumococcal diseases in the late post-transplant period. Among the 22,514 recipients who received allo-HSCT over an 11-year period and could be followed for ≥100 days, 43 patients developed 49 episodes of pneumococcal diseases. Six of the 43 patients died from pneumococcal diseases, and four of these six patients died within a week, despite having undergone allo-HSCT two or more years ago. A history of chronic graft-versus-host disease (odds ratio [OR], 2.31; 95% confidence interval [CI], 1.15–4.66; P = 0.02), viral infection (OR, 3.38; 95% CI, 1.70–6.72; P < 0.01), and complete remission of the underlying disease at the time of transplantation (OR, 2.38; 95%CI, 1.10–5.14; P = 0.03) were identified as risk factors. Given the risk of sudden death and the high mortality rate, attention should be paid to pneumococcal diseases in providing long-term follow-up care, even several years after allo-HSCT.

Case Commentary: "Salvage Treatment of Refractory HSV Oral Lesions with Pritelivir in Allogeneic Hematopoietic Cell Transplant Recipients" by Bosetti et al.

Case Commentary: "Salvage Treatment of Refractory HSV Oral Lesions with Pritelivir in Allogeneic Hematopoietic Cell Transplant Recipients" by Bosetti et al.

Third BNT162b2 mRNA SARS-CoV-2 Vaccine Dose Significantly Enhances Immunogenicity in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation.

COVID-19-related mortality among hematopoietic stem cell transplantation (HSCT) recipients in the pre-vaccine era ranged between 22 and 33%. The Pfizer/BioNTech BNT162b2 vaccine demonstrated significant immunogenicity and efficacy in the healthy population; however, its long-term effects on allogeneic HSCT recipients remained unclear. Our study longitudinally evaluated humoral and cellular responses to the BNT162b2 vaccine in adult allogeneic HSCT patients. A positive response was defined as antibody titers ≥ 150 AU/mL post-second vaccination. Among 77 included patients, 51 (66.2%) responded to vaccination. Response-associated factors were female gender, recent anti-CD20 therapy, and a longer interval between transplant and vaccination. Response rates reached 83.7% in patients vaccinated >12 months post-transplant. At 6 months post-second vaccination, antibody titers dropped, but were significantly increased with the booster dose. Moreover, 43% (6/14) of non-responders to the second vaccination acquired sufficient antibody titers after booster administration, resulting in an overall response rate of 79.5% for the entire cohort. The BNT162b2 vaccine was effective in allogeneic transplant recipients. Although antibody titers decreased with time, the third vaccination led to their significant elevation, with 93% of third-dose responders maintaining titers above 150 AU/mL at 3 months post-administration.

Ex vivo reprogramming of human hematopoietic stem cells is accompanied by increased transcripts of genes regulating metabolic integrity

The regenerative potential of human hematopoietic stem cells (HSCs) is functionally defined by their ability to provide life-long blood cell production and to repopulate myeloablated allogeneic transplant recipients. The expansion of HSC numbers is dependent not only on HSC divisions but also on a coordinated adaptation of HSCs to metabolic stress. These variables are especially critical during the ex vivo culture of HSCs with cytokine combinations, which frequently results in HSC exhaustion. We have previously reported that human CD34+ hematopoietic stem and progenitor cells (HSPCs) can be efficiently reprogrammed ex vivo and that the number of phenotypic HSCs with long-term repopulation capacity is expanded in the presence of a combination of cytokines and an epigenetic modifier. Here, we present evidence that ex vivo HSC reprogramming and maintenance is accompanied by increased transcripts of genes regulating metabolic integrity, including SIRT1 and SIRT3.

CMV Infection After Letermovir Primary Prophylaxis Discontinuation in Allogeneic Hematopoietic Cell Transplant Recipients.

In this single-center study of 61 allogeneic hematopoietic cell transplant (HCT) recipients receiving letermovir primary cytomegalovirus (CMV) prophylaxis for the first 100 days, we report 23% incidence of clinically significant CMV infection during the first 100 days after letermovir discontinuation, predominately in haploidentical HCT recipients, without any associations with CMV-DNAemia under letermovir.

Association Between Candidemia and Noninfectious Interstitial Pneumonia After Allogeneic Hematopoietic Cell Transplantation: JSTCT Transplant Complications Working Group.

α-mannan from Candida albicans reportedly induces Th17-mediated pulmonary graft-versus-host disease (GVHD) in mouse models. This study aimed to evaluate the association between candidemia and noninfectious interstitial pneumonia (IP) in allogeneic hematopoietic cell transplantation (HCT) recipients. Using a Japanese transplant registry database, we analyzed 9143 pediatric and adult patients with hematological malignancies who underwent their first (n = 7531) or second (n = 1612) allogeneic HCT between 2009 and 2019. Noninfectious IP was observed in 694 patients at a median (range) of 63 (0-1292) days after HCT. Candidemia occurred in 358 patients at a median (range) of 31 (0-903) days after HCT. Candidemia treated as a time-dependent covariate was significantly associated with an increased incidence of noninfectious IP (hazard ratio [HR], 2.51; 95% CI, 1.48-4.25), along with total body irradiation (>8 Gy; HR, 1.57; 95% CI, 1.18-2.10) and malignant lymphoma (vs acute myeloid leukemia; HR, 1.30; 95% CI, 1.004-1.69). On the other hand, prompt platelet recovery (HR, 0.58; 95% CI, 0.45-0.75) and acute lymphoblastic leukemia (vs acute myeloid leukemia; HR, 0.68; 95% CI, 0.49-0.94) were associated with reduced incidence of noninfectious IP. The median survival after the development of noninfectious IP in patients with prior candidemia was significantly shorter than that in those without it (22 days vs 59 days; P < .001). Candidemia was associated with an increased incidence of noninfectious IP. The prognosis of noninfectious IP after candidemia was extremely poor.

Salvage Treatment of Refractory HSV Oral Lesions with Pritelivir in Allogeneic Hematopoietic Cell Transplant Recipients.

We present two allogeneic hematopoietic cell transplantation recipients (HCTr) treated with pritelivir for acyclovir-resistant/refractory (r/r) HSV infection based on the expanded access program of the pritelivir manufacturer. Outpatient treatment with pritelivir was administered, with partial response by week 1 of treatment and complete response by week 4 of treatment in both patients. No adverse events were noted. Pritelivir appears to be an effective and safe option for the management of acyclovir-r/r HSV infections in highly immunocompromised patients in an outpatient setting.

Risk of bloodstream infections in allogeneic hematopoietic cell transplant recipients according to gut mucosal colonization and fluoroquinolone implementation during neutropenia

Background . Higher rate of gram-negative bloodstream infections (BSI) have been recently documented from transplantation centers providing fluoroquinolone (FQ) prophylaxis. Aim . To define the incidence of BSI during neutropenia according to gut mucosal colonization with resistant gramnegative bacteria and FQ administration. Materials and methods . Of 284 allogeneic hematopoietic cell transplant recipients included in the study, 154 (54.2 %) were identified as colonized with resistant gram-negative bacteria, and 130 (45.8 %) patients as non-colonized. Resistant gram-negative bacteria included Enterobacterales with extended spectrum beta-lactamase production, carbapenem-resistant Enterobacterales, Stenotrophomonas maltophilia , and carbapenem-resistant strains of Pseudomonas aeruginosa . Colonized patients did not receive FQ prophylaxis (n = 147) except 7 patients who received FQ as sequential therapy due to residual inflammatory lung lesions. Among non-colonized patients 98 received FQ prophylaxis, whereas 32 did not. Results . Probability of gram-negative BSI (71.4 %; p &lt;0.0001), and extended spectrum beta-lactamase-producing Enterobacterales BSI (57.1 %; p &lt;0.0001) was significantly higher in colonized patients receiving FQ. No significant difference was found in probability of gram-positive BSI (p = 0.452). In multivariate analysis colonized patients with (hazard ratio (HR) 35.32; 95 % confidence interval (CI) 9.15–136.44; p &lt;0.0001) or without FQ (HR 3.44; 95 % CI 1.15–10.31; p = 0.007), omission of FQ in non-colonized patients (HR 4.03; 95 % CI 1.08–15.00; p = 0.038), and active disease before allogeneic hematopoietic cell transplantation (HR 2.17; 95 % CI 1.03–4.63; p = 0.042) were associated with higher risk of gram-negative BSI, whereas mismatched unrelated donor transplantations were associated with higher gram-positive BSI risk (HR 3.84; 95 % CI 1.63–9.08; p = 0,009). Conclusion . Colonization with multiresistant gram-negative bacteria is a predictor of gram-negative BSI, including multiresistant pathogens, especially when FQ are prescribed during neutropenia, while in non-colonized patients FQ prophylaxis is an effective approach significantly reducing gram-negative BSI.

Central line-associated Rhizobium radiobacter bloodstream infection in two allogeneic hematopoietic cell transplant recipients.

Rhizobium radiobacter is a gram-negative, opportunistic phytopathogen that rarely causes human infections. We report two cases of Rhizobium radiobacter central line-associated bloodstream infection (CLABSI) in allogeneic hematopoietic cell transplantation (alloHCT) recipients. We review previous reports and common microbiological characteristics associated with this organism. Two adult males developed R. radiobacter CLABSIs at day +81 and day +77 post-alloHCT. Patient one was asymptomatic on presentation while patient two was febrile. One patient had a polymicrobial infection, which has not been previously described. The presence of high-level ceftazidime resistance in both patients suggests third-generation cephalosporin resistance may be more common than previously recognized. For both patients, microbiologic clearance was achieved through peripherally inserted central catheter removal and initiation of intravenous cefepime. Antibiotic therapy was narrowed to oral levofloxacin for a total 14-day course from the time of first negative blood culture. There has been no subsequent recurrence of R. radiobacter infection at 12 and 5 months of follow-up for patients one and two, respectively. These two cases add to the scant literature characterizing R. radiobacter infection following alloHCT. Immunosuppressive agents for graft-versus-host disease prophylaxis may have predisposed these patients to R. radiobacter infection. Our reports, and previously reported cases, suggest R. radiobacter exhibits low virulence, mild symptom burden, and does not confer a high mortality risk. In the alloHCT setting, further accumulation of cases is needed to aid in understanding clinical features and characteristics of R. radiobacter infection.