Trajectory of Sleep, Depression, and Quality of Life in Pediatric HSCT Recipients.

Disrupted sleep is commonly reported during hematopoietic stem cell transplant. In this study, we use actigraphy to measure sleep parameters, and qualitative measures of quality of life, depression, and sleep in pediatric and young adult transplant recipients to describe their time course through transplant. Eight patients had evaluable actigraphy data, and 10 patients completed the surveys. The median age of the 6 male and 7 female participants was 13.94 years old. Sleep duration and efficiency measured by actigraphy were suboptimal prior to transplant, then declined to a nadir between Day +7 to +14. Self-reported sleep quality, depression, and quality of life were worst at Day +14 to +30 but improved by Day +100. Findings support efforts to improve sleep, which may improve recovery, mental health and quality of life.

Third-party virus specific T cells for the treatment of double stranded DNA viral reactivation and PTLD after solid organ transplant.

Reactivation or primary infection with double stranded DNA viruses is common in recipients of solid organ transplants and is associated with significant morbidity and mortality. Treatment with conventional anti-viral medications is limited by toxicities, resistance, and lack of effective options for adenovirus and BKPyV. Virus-specific T-cells (VSTs) have been shown to be an effective treatment for infections with adenovirus, BKPyV, cytomegalovirus (CMV), and Epstein-Barr virus (EBV). Most of these studies have been conducted in stem cell recipients and no large studies have been published in the solid organ transplant population to date. In this study we report on the outcome of quadrivalent third party VST infusions in 98 recipients of solid organ transplants in the context of an open label phase 2 trial. The ninety-eight patients received a total of 181 infusions, with a median of 2 infusions per patient. The overall response rate was 45% for BKPyV, 65% for CMV, 68% for Adenovirus, and 61% for EBV. Twenty percent of patients with PTLD had a complete response and 40% a partial response. All the VST infusions were well tolerated. We conclude that VSTs are safe and effective in the treatment of viral infections in solid organ transplant recipients.

Uncommon BK polyomaviruses detected in allogeneic hematopoietic cell transplant recipients.

The role of viral diversity in the pathogenesis of BK polyomavirus (BKPyV)-associated disease is poorly understood. Here, we report near full-length BKPyV genome sequences from two allogeneic hematopoietic cell transplant recipients infected with BKPyV genotype II, which is uncommon in the USA.

Fanconi Anemia Neuroinflammatory Syndrome (FANS): Brain Lesions and Neurologic Injury in Fanconi Anemia.

Fanconi anemia (FA) is a complex inherited bone marrow failure syndrome characterized by chromosomal instability and defective DNA repair causing sensitivity to DNA interstrand cross-linking agents. Our understanding of the full adult phenotype of the disease continues to evolve, as most patients with Fanconi Anemia died of marrow failure in the first decade of life prior to more recent advances in allogeneic hematopoietic cell transplantation. Herein, we report a previously undescribed, clinically concerning, progressive neurologic syndrome in patients with FA. Nine non-immunosuppressed pediatric patients and young adults with FA presented with acute and chronic neurological signs and symptoms associated with distinct neuroradiological findings. Symptoms included, but were not limited to, limb weakness, papilledema, gait abnormalities, headaches, dysphagia, visual changes, and seizures. Brain imaging demonstrated a characteristic radiographic appearance of numerous cerebral and cerebellar lesions with associated calcifications and often a dominant ring enhancing lesion. Tissue from the dominant brain lesions in 4 patients showed non-specific atypical glial proliferation, and a small number of polyomavirus infected microglial cells identified by immunohistochemistry in 2 patients. Numerous interventions were pursued across this cohort, in general with no improvement. Overall, these patients demonstrated significant progressive neurologic decline. This cohort highlights the importance of recognizing Fanconi Anemia Neuroinflammatory Syndrome (FANS), which is distinct from malignancy and warrants careful ongoing evaluation by clinicians.

Ruxolitinib Pharmacokinetics and Pharmacodynamics in Children with Acute and Chronic Graft-versus-Host Disease.

We evaluated the pharmacokinetics (PK) of oral ruxolitinib in children with steroid-refractory acute graft-versus-host disease (aGVHD) (age <12 years) and chronic GVHD (cGVHD) (age ≤18 years) using our published pediatric dosing. PK sampling was performed before and 2 hours after ruxolitinib administration in patients with established cGVHD. More extensive PK analyses were performed in patients with newly diagnosed aGVHD or cGVHD before and .5, 1, 2, 4, and 6 hours after ruxolitinib administration in patients weighing >10 kg and before, 3+, and 6+ hours in children weighing <10 kg. pSTAT1, pSTAT3, and pSTAT5 expression levels were measured on CD4+ and CD8+ T cells before and 2 hours after ruxolitinib administration as a pharmacodynamic marker of JAK/STAT inhibition. Thirteen patients were prospectively enrolled, including 8 with existing cGVHD (age 0 to ≤18 years), 4 with new-onset steroid-refractory aGVHD (age 0 to <12 years) and 1 with newly diagnosed steroid-refractory cGVHD. Great variability in PK was seen. Mean oral clearance (CL/F) was 7.76 ± 4.09 L/h (range, 3.1 to 15.3 L/h). The average elimination half-life was 2.32 ± 1.0 hours. Mean ruxolitinib clearance was higher in children age <2 years versus those age >2 years (12.1 ± 3.0 L/h versus 5.7 ± 2.8 L/h; P = .005) and was reduced with concurrent treatment with azoles and azithromycin. We saw a variable reduction in pSTAT1/3/5 expression on T cells at time of peak ruxolitinib absorption (2 hours after dosing). Children <10 kg had lower ruxolitinib exposure, possibly due to inherent increased drug clearance or variability in dosing methods, leading to decreased drug absorption.

Use of Teduglutide in the Management of Gastrointestinal Graft-versus-Host Disease in Children and Young Adults.

Loss of intestinal L cells and reduced levels of glucagon-like peptide-2 (GLP-2) have been implicated in acute graft-versus-host disease (GVHD) in murine models. Teduglutide, a human recombinant GLP-2 analog, may be beneficial in acute gastrointestinal (GI) GVHD owing to its known tissue protective and regenerative functions. We retrospectively reviewed patients who received teduglutide for treatment of GI GVHD. Endoscopy was performed at diagnosis and at completion of the teduglutide course. GLP-1 immunohistochemistry (IHC) was performed at diagnosis and the end of teduglutide therapy in 2 patients to evaluate L cells. We initiated daily teduglutide 0.05 mg/kg subcutaneously as adjunctive therapy in 3 pediatric patients with refractory GI GVHD. All 3 patients had resolution of GI GVHD following completion of the teduglutide course, as evidenced by reduced apoptosis and regenerative changes on post-treatment endoscopy. Reportable GLP-1 IHC in 2 patients demonstrated increased L cells at the end of teduglutide treatment compared to at diagnosis. No adverse effects to teduglutide were observed. Teduglutide is a promising adjunctive and non-immune suppressive agent for managing acute GI GVHD.

Social determinants of health predict health outcomes following pediatric allogeneic hematopoietic stem cell transplant.

BACKGROUND: Pediatric hematopoietic stem cell transplantation (HCT) is an intensive medical procedure that places substantial financial and logistical burdens on families and is associated with significant health risks, such as graft-versus-host disease (GVHD), and infections. The influence of the social determinants of health (SDoH) on outcomes following pediatric HCT is understudied. This study aimed to examine whether SDoH predicts outcomes following pediatric HCT. PROCEDURE: Data were collected from 84 children who received HCT (Mage  = 5.8 years, SD = 3.7) and their primary caregiver. Detailed demographic information was collected from caregivers at baseline, and child health information was extracted from the electronic medical records. Multivariate logistic regression was used to examine the association between SDoH and health outcomes within a 24-month period following pediatric HCT. RESULTS: After controlling for malignancy as reason for transplant and donor type, lower family income predicted the incidence of chronic GVHD. Neighborhood deprivation, total family income, public health insurance, caregiver relationship status, caregiver educational attainment, and perceived family financial difficulties did not predict acute GVHD or the number of infections. CONCLUSIONS: Total family income is a simple family indicator of SDoH that predicts chronic GVHD after pediatric allogeneic HCT. These findings provide further support for the importance of screening of child and family SDoH risks to ensure that fundamental needs can be met to mitigate potential health disparities for up to 2 years following pediatric HCT.

The Phenotype of a Bone Marrow Transplant Nurse: Survival of the Fittest.

There is a need for proficient nursing practice in specialized critical care settings, such as a pediatric Bone Marrow Transplant (BMT) Unit. The staffing crisis continues to be problematic for areas around the country. Nursing tenure has been positively correlated with improving patient outcomes and confidence in giving care, so efforts must be made to retain pediatric BMT nurses. The purpose of this study was to investigate factors of resilience and how it pertains to the retention of pediatric BMT nurses through (1) Understanding current BMT nursing turnover and trend why nurses are leaving; (2) Measure resilience throughout BMT nursing cohort, covering all tenure of nurses; and (3) Interview senior nurses within the cohort to identify themes relating to retention and resilience using grounded theory methodology. This research was carried out in the Bone Marrow Transplant (BMT) Unit at Cincinnati Children's Hospital Medical Center (CCHMC). The study spanned from 2014 to 2019, during which researchers gathered extensive data to evaluate the turnover risk among BMT nurses. A detailed follow-up was conducted in 2019 to further assess this risk. To measure resilience levels, a group of 115 nurses in the unit completed the Connor Davidson Resilience Scale (CD-RISC). Additionally, in-depth interviews were conducted with 9 senior nurses in the cohort, continuing until theoretical saturation was reached, ensuring a comprehensive understanding of the factors influencing nurse turnover in the unit. Researchers looked retrospectively at nursing turnover from 2014 to 2019. Investigators determined the risk of new nurses leaving was between 22 and 24 months (HR 0.025). Further, follow-up was conducted for data points between 2019-present time, which showed a drastic change in the hazard rate curvature. However, the risk remained relatively the same at 22 to 24 months (HR 0.03). There was no statistical significance found between CD-RISC results and age (P = .465), gender (P = .725), working experience (P = .15), or education (P = .14). Through a constant comparative process, several themes were identified as positive, negative, and ambiguous contributions to the retention of nurses. The risk of nurses leaving after 2 years decreases significantly; therefore, we determined that a nurse with a commitment to pediatric BMT occurs with 2 years' experience. Although our initial hypothesis was that senior nurses had greater resilience than less tenured nurses, there was no statistical significance as the effect of resilience is small. However, we identified several additional factors pertinent to the pediatric BMT field which may be associated with nursing retention.

A randomized phase 2 trial of oral vitamin A for graft-versus-host disease in children and young adults.

ABSTRACT: Vitamin A plays a key role in the maintenance of gastrointestinal homeostasis and promotes a tolerogenic phenotype in tissue resident macrophages. We conducted a prospective randomized double-blinded placebo-controlled clinical trial in which 80 recipients of hematopoietic stem cell transplantation (HSCT) were randomized 1:1 to receive pretransplant high-dose vitamin A or placebo. A single oral dose of vitamin A of 4000 IU/kg, maximum 250 000 IU was given before conditioning. The primary end point was incidence of acute graft-versus-host disease (GVHD) at day +100. In an intent-to-treat analysis, incidence of acute GVHD was 12.5% in the vitamin A arm and 20% in the placebo arm (P = .5). Incidence of acute gastrointestinal (GI) GVHD was 2.5% in the vitamin A arm (P = .09) and 12.5% in the placebo arm at day +180. Incidence of chronic GVHD was 5% in the vitamin A arm and 15% in the placebo arm (P = .02) at 1 year. In an "as treated" analysis, cumulative incidence of acute GI GVHD at day +180 was 0% and 12.5% in recipients of vitamin A and placebo, respectively (P = .02), and cumulative incidence of chronic GVHD was 2.7% and 15% in recipients of vitamin A and placebo, respectively (P = .01). The only possibly attributable toxicity was asymptomatic grade 3 hyperbilirubinemia in 1 recipient of vitamin A at day +30, which self-resolved. Absolute CCR9+ CD8+ effector memory T cells, reflecting gut T-cell trafficking, were lower in the vitamin A arm at day +30 after HSCT (P = .01). Levels of serum amyloid A-1, a vitamin A transport protein with proinflammatory effects, were lower in the vitamin A arm. The vitamin A arm had lower interleukin-6 (IL-6), IL-8, and suppressor of tumorigenicity 2 levels and likely a more favorable gut microbiome and short chain fatty acids. Pre-HSCT oral vitamin A is inexpensive, has low toxicity, and reduces GVHD. This trial was registered at www.ClinicalTrials.gov as NCT03202849.

Liver abnormalities are frequent and persistent in patients with Fanconi anemia.

ABSTRACT: Liver disease has not been well described in patients with Fanconi anemia (FA). Improvements in outcomes of transplant mean that more individuals with FA are reaching adulthood and new features of the FA phenotype are being discovered. We performed a retrospective review of liver function in a cohort of 97 patients with FA followed-up for at least 10 years at a single center. We identified a high frequency of transaminitis (n = 31, 32%) without elevation of bilirubin and with no evidence of structural hepatic abnormality in patients with FA. Transaminitis was persistent in many cases, sometimes lasting more than a decade without clinical manifestation, although 2 patients with prolonged transaminitis are deceased from liver failure, indicating important long-term clinical consequences. Transaminitis was found in patients who had and had not received transplant but was more frequent in recipients of transplant. Exposure to total body irradiation increased risk (odds ratio, 15.5 [95% confidence interval, 2.44-304.54]; P = .01), whereas treatment with androgens did not. Review of limited numbers of liver biopsies and autopsy material showed a cholestatic pattern of liver injury, with progressive fibrosis, in the majority of patients. Occurrence in cases without transplant as well as cases with transplant argues against a potential diagnosis of atypical liver graft-versus-host disease. Limited data regarding therapy suggest no benefit from treatment with steroids or other immune suppressive medications or ursodeoxycholic acid. Our data show that liver disease is common in patients with FA, and because most children with FA now reach adulthood, end-stage liver disease in young adulthood means systematic testing of potential therapies is urgently needed.

Pre-transplant glomerular hyperfiltration is not a risk factor for increased renal morbidity and mortality in pediatric stem cell transplant patients.

Low glomerular filtration rate (GFR) prior to stem cell transplant (SCT) is associated with increased morbidity and mortality. The implications of abnormally high GFRs, or glomerular hyperfiltration, prior to SCT are unknown. Twenty-two of 74 consecutive pediatric SCT patients over 2 years old at a single center were hyperfiltrating prior to SCT, median nuclear medicine GFR 154 mL/min/1.73 m2 [interquartile range: 146-170]. There was no association between hyperfiltration and any transplant demographics, nor between hyperfiltration and acute kidney injury (p = .8), renal replacement therapy (p = .63), 1-year event-free survival (p = 1), or abnormal creatinine-based estimated GFR at a median follow-up of 4.7 years (p = .73).

Prospective Multi-Institutional Study of Eculizumab to Treat High-Risk Stem Cell Transplant Associated TMA.

High-risk, complement mediated, untreated transplant-associated thrombotic microangiopathy (hrTMA) has dismal outcomes due to multi-organ dysfunction (MODS). The complement C5 blocker eculizumab shows promising results in hrTMA, but has not been prospectively studied in hematopoietic stem cell transplant (HCT) recipients. We performed the first multi-institutional prospective study in children and young adults to evaluate eculizumab as an early targeted intervention for hrTMA/MODS (NCT03518203). We hypothesized that eculizumab would more than double survival in HCT recipients with hrTMA, compared to our prior study of prospectively screened, untreated hrTMAs serving as historical controls. High-risk TA-TMA features (elevated terminal complement (sC5b-9) and proteinuria measured by random urine protein/creatinine ratio (≥1mg/mg)) were required for inclusion. The primary endpoint was survival at six-months from hrTMA diagnosis. Secondary endpoints were cumulative incidence of MODS six-months after hrTMA diagnosis and one-year post-transplant survival. The eculizumab dosing regimen included intensive loading, induction, and maintenance phases for up to 24 weeks of therapy. All 21 evaluated study subjects with hrTMA had MODS. Primary and secondary study endpoints were met by demonstrating survival of 71% (p<0.0001) six months after hrTMA diagnosis and 62% one year after-transplant. Eleven of fifteen survivors (73%) fully recovered organ function and are well. Our study demonstrates significant improvement in survival and recovery of organ function in hrTMA using an intensified eculizumab dosing regimen and real time TA-TMA biomarker monitoring. This study serves as a benchmark for planning future studies that should focus on preventative measures or targeted therapy that can be initiated prior to organ injury. ClinicalTrials.gov (NCT03518203).

Proceedings of the 2023 Second Annual ASTCT-NMDP ACCESS Initiative Workshop.

Here the proceedings from the Second Annual American Society for Transplantation and Cellular Therapy (ASTCT) and National Marrow Donor Program (NMDP) ACCESS Initiative are reviewed to inform the hematopoietic cell transplantation (HCT) and cellular therapy (CT) ecosystem about progress and direction of the collaborative. Highlights from the meeting, including updates on the progress of projects from the Awareness, Poverty, and Racial Inequity Committees, are presented. The ACCESS Initiative continues to evolve and will remain dependent on the HCT/CT ecosystem's continued dedication to reduce barriers and improve outcome disparities for all patients in need of HCT/CT.

Assessing Medicaid Coverage for Hematopoietic Cell Transplantation and Chimeric Antigen Receptor T Cell Therapy: A Project from the American Society for Transplantation and Cellular Therapy and the National Marrow Donor Program ACCESS Initiative.

The American Society for Transplantation and Cellular Therapy (ASTCT) and the National Marrow Donor Program (NMDP) formed the ACCESS Initiative to address and reduce barriers to hematopoietic cell transplantation (HCT) and cellular therapy (CT) to ensure equal access and outcomes for all patients in need. The 3 committees, addressing awareness, poverty, and racial and ethnic inequity, defined pilot projects focusing on addressing relevant barriers to HCT/CT. Because many socioeconomically disadvantaged HCT/CT recipients receive care through state Medicaid programs, the Poverty Committee conducted a Medicaid scan of all 50 US states with the following objectives: to define beneficiary coverage for allogeneic and autologous HCT and chimeric antigen receptor (CAR) T cell therapy; to define support for travel, temporary lodging, and meals for both beneficiaries and caregivers; and to determine search and cell acquisition payment procedures. Here we summarize the results of the Medicaid scan and highlight significant variations and gaps in coverage for HCT/CT recipients. We also provide an initial roadmap for addressing gaps in Medicaid support for HCT and CAR-T therapy recipients.

Increased Body Mass Index Augments Endothelial Injury and Clinical Outcomes after Hematopoietic Stem Cell Transplantation.

Higher body mass index (BMI) is characterized as a chronic inflammatory state with endothelial dysfunction. Endothelial injury after allogeneic hematopoietic stem cell transplantation (allo-HSCT) puts patients at risk for such complications as transplantation-associated thrombotic microangiopathy (TA-TMA) and acute graft-versus-host-disease (aGVHD). To evaluate the impact of increased BMI on endothelial injury after allo-HSCT in pediatric and young adult patients, we conducted a retrospective cohort study evaluating 476 consecutive allo-HSCT children and young adult recipients age 0 to 20 years. Our analysis was subdivided based on distinct age categories (<2 years and 2 to 20 years). BMI was considered as a variable but was also expressed in standard deviations from the mean adjusted for age and sex (z-score), based on established criteria from the World Health Organization (age <2 years) and the Centers for Disease Control and Prevention (age 2 to 20 years) to account for differences associated with age. Primary endpoints included the incidences of TA-TMA and aGVHD. Increased BMI z-score was associated with TA-TMA after allo-HSCT in patients age <2 years (median, 18.1; IQR, 17 to 20; P = .006) and in patients age 2 to 20 years (median, 18.7; IQR, 16 to 21.9; P = .02). Higher BMI z-score correlated with TA-TMA risk in both age groups, with a BMI z-score of .9 in the younger cohort and .7 (IQR, -.4 to 1.6; P = .04) in the older cohort. Increased BMI z-score was associated with an increased risk of TA-TMA in a multivariate analysis of the entire cohort (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.05 to 1.37; P = .008). Multivariate analysis also demonstrated that patients with BMI in the 85th percentile or greater had an increased risk of developing TA-TMA compared to those with a lower BMI percentile (OR, 2.66; 95% CI, 1.62 to 4.32; P < .001). Baseline and day +7 ST2 levels were elevated in subjects with TA-TMA compared to those without TA-TMA in both age groups. Baseline sC5b-9 concentration was not correlated with BMI z-score, but sC5b-9 concentration was increased markedly by 7 days post-allo-HSCT in patients age <2 years who later developed TA-TMA compared to those who never developed TA-TMA (P = .001). The median BMI z-score was higher for patients with aGVHD compared to patients without aGVHD (.7 [range, -3.9 to 3.9] versus .2 [range, -7.8 to 5.4]; P = .03). We show that high BMI is associated with augmented risk of endothelial injury after HSCT, specifically TA-TMA. These data identify a high-risk population likely to benefit from early interventions to prevent endothelial injury and prompt treatment of established endothelial injury.

Optimized vitamin D repletion with oral thin film cholecalciferol in patients undergoing stem cell transplant.

Vitamin D deficiency is common in childhood, pervasive before and after bone marrow transplant, and is associated with increased incidence of graft-versus-host disease (GVHD) and decreased survival in patients undergoing hematopoietic stem cell transplant (HSCT). Numerous barriers impede replacement, including malabsorption secondary to gut GVHD, mucositis, inability to take capsules, kidney disease, liver disease, and infection; many patients remain refractory despite vitamin D therapy. We hypothesized that a different formulation of cholecalciferol, administered on the tongue as a readily dissolving oral thin film (OTF), would ease administration and facilitate therapeutic vitamin D levels (>35 ng/mL) in patients who are refractory. In this prospective pilot study, we evaluated 20 patients after HSCT (range, day +21 - day +428 at enrollment) with serum vitamin D levels ≤35 ng/mL. Cholecalciferol OTF strips were administered for 12 weeks. Dosing was based on patient body weight and titrated per individual pharmacokinetics. Wilcoxon matched-pairs signed-rank test demonstrated marked improvement in all 20 patients who were formerly refractory, increasing from a median baseline vitamin D level of 29.2 ng/mL to 58 ng/mL at end of study (P < .0001). All patients demonstrated improvement in serum vitamin D level by week 4 on study, some of whom had been refractory for years prior. Median dose was 1 OTF strip (40 000 IU) per week. No toxicity was observed. This formulation proved to be safe, effective, efficient, and well received. We are eager to explore other patient populations, which might benefit from this promising development, and other therapeutics that might be optimized using this mode of delivery. This trial was registered at www.clinicaltrials.gov as #NCT04818957.

BK Polyomavirus Diversity After Hematopoietic Stem Cell Transplantation.

BK polyomavirus (BKPyV) infection is common after hematopoietic stem cell transplantation (HSCT) and is associated with the development of hemorrhagic cystitis (HC). The role that BKPyV plays in the pathogenesis of HC is not well characterized. We investigated the impact of BKPyV diversity on the development of HC using a previously established cohort of pediatric HSCT patients. There were 147 urine samples with quantifiable BKPyV at month 1 after HSCT; 137 (93.2%) were amplified using our in-house polymerase chain reaction approach and sent for next-generation sequencing. Subtype Ia was most frequent (61.3%), followed by subtype Ib1 (31.4%). The median viral load of subtype Ia samples was higher than for subtype Ib1 at month 1. Across the protein coding regions, APOBEC-induced mutations and signature patterns associated with HC were identified. This is the largest sequencing study of a single cohort of HSCT patients, providing a vast resource of sequence data for future analyses.

Intestinal permeability in patients undergoing stem cell transplantation correlates with systemic acute phase responses and dysbiosis.

Intestinal permeability may correlate with adverse outcomes during hematopoietic stem cell transplantation (HSCT), but longitudinal quantification with traditional oral mannitol and lactulose is not feasible in HSCT recipients because of mucositis and diarrhea. A modified lactulose:rhamnose (LR) assay is validated in children with environmental enteritis. Our study objective was to quantify peri-HSCT intestinal permeability changes using the modified LR assay. The LR assay was administered before transplant, at day +7 and +30 to 80 pediatric and young adult patients who received allogeneic HSCT. Lactulose and rhamnose were detected using urine mass spectrometry and expressed as an L:R ratio. Metagenomic shotgun sequencing of stool for microbiome analyses and enzyme-linked immunosorbent assay analyses of plasma lipopolysaccharide binding protein (LBP), ST2, REG3α, claudin1, occludin, and intestinal alkaline phosphatase were performed at the same timepoints. L:R ratios were increased at day +7 but returned to baseline at day +30 in most patients (P = .014). Conditioning regimen intensity did not affect the trajectory of L:R (P = .39). Baseline L:R ratios did not vary with diagnosis. L:R correlated with LBP levels (r2 = 0.208; P = .0014). High L:R ratios were associated with lower microbiome diversity (P = .035), loss of anaerobic organisms (P = .020), and higher plasma LBP (P = .0014). No adverse gastrointestinal effects occurred because of LR. Intestinal permeability as measured through L:R ratios after allogeneic HSCT correlates with intestinal dysbiosis and elevated plasma LBP. The LR assay is well-tolerated and may identify transplant recipients who are more likely to experience adverse outcomes.