Reduced-Intensity Conditioning Allogeneic Stem Cell Transplantation in Pediatric Patients and Subsequent Supportive Care

637

542

The relationship between intestinal microbiota composition and acute graft-versus-host disease (GVHD) after allogeneic blood/marrow transplantation (allo BMT) is not well understood. Intestinal bacteria have long been thought to contribute to GVHD pathophysiology, but recent animal studies in non-transplant settings have found that anti-inflammatory effects are mediated by certain subpopulations of intestinal commensals. Hypothesizing that a more nuanced relationship may exist between the intestinal bacteria and GVHD, we evaluated the fecal bacterial composition of 64 patients 12 days after BMT. We found that increased bacterial diversity was associated with reduced GVHD-related mortality. Furthermore, harboring increased amounts of bacteria belonging to the genus Blautia was associated with reduced GVHD lethality in this cohort and was confirmed in another independent cohort of 51 patients from the same institution. Blautia abundance was also associated with improved overall survival. We evaluated the abundance of Blautia with respect to clinical factors and found that loss of Blautia was associated with: 1) treatment with antibiotics that inhibit anaerobic bacteria and 2) receiving total parenteral nutrition (TPN) for longer durations. We conclude that increased abundance of commensal bacteria belonging to the Blautia genus is associated with reduced lethal GVHD and improved overall survival.

Section: Discussioncontrasting

confidence: 84%

Intestinal Blautia Is Associated with Reduced Death from Graft-versus-Host Disease

Jenq

Taur

Devlin

et al. 2015

637

542

“…BBSI has been previously identified as a risk factor for LI [20], but the mechanism for this remains unclear. It is plausible that during the early posteallo-HSCT period, recipients of MAC have higher grades of mucositis, which could lead to transmigration of gastrointestinal bacteria into the bloodstream, resulting in sepsis [21]. The association between bacterial infection during the first 30 days after allo-HSCT and hyperbilirubinemia at 1 month and its impact on subsequent TRM is intriguing.…”

Section: Discussionmentioning

confidence: 99%

Risk Factors Associated with Liver Injury and Impact of Liver Injury on Transplantation-Related Mortality in Pediatric Recipients of Allogeneic Hematopoietic Stem Cell Transplantation

Radhakrishnan

Bishop

Jin

et al. 2013

Self Cite

In adults, hepatic complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT) are associated with significant morbidity and transplantation-related mortality (TRM). However, there is a paucity of parallel data on the incidence of, and risk factors for, liver injury (LI) and the impact of LI on TRM in pediatric allo-HSCT recipients. We compared total bilirubin, direct bilirubin, and alanine aminotransferase values before allo-HSCT and at 1 month, day +100, and 12 months after allo-HSCT in 248 patients who received either a myeloablative conditioning (MAC) regimen (n = 109) or a reduced-toxicity/reduced-intensity conditioning (RTC/RIC) regimen (n = 139). LI was defined as grade ≥ 2 hyperbilirubinemia according to the National Cancer Institute's Common Terminology Criteria for Adverse Events 3.0/4.0 (total bilirubin, >1.95 mg/dL, 1.5 times above the upper limit of normal for our laboratory). Univariate and multivariate logistic regression models were used to identify risk factors for LI and TRM. The incidence of LI at 1 month after allo-HSCT was 14.1%. The median bilirubin level was 3.5 mg/dL (range, 1.97 to 32.2 mg/dL). Only LI as defined by total bilirubin level, but not by direct bilirubin or alanine aminotransferase level, was found to be a significant predictor for TRM. The 1-year TRM was 60.7% (95% confidence interval, 42.6% to 78.7%) in patients with LI at 1 month after allo-HSCT, compared with 14.6% (95% confidence interval, 9.9% to 19.4%) (P < .0001) in patients those who did not have liver injury. Multivariate analysis identified age (P = .03), total body irradiation (P = .007), bacterial bloodstream infection (BBSI) (P = .001), and invasive fungal infection (IFI) (P = .002) as significant risk factors for developing LI at 1 month. On multivariate analysis for risk factors for TRM, only LI at 1 month after allo-HSCT (P < .0001), primary graft failure (P = .001), BBSI (P = .003), and systemic viral infection (P = .04) were identified as significant risk factors for TRM. LI before allo-HSCT conditioning was not associated with higher TRM. Although the incidence of LI in pediatric allo-HSCT recipients is low, LI is associated with very high TRM. BBSI and IFI are the primary risk factors for LI.

“…Reduced-intensity regimens contained busulfan (6.4 mg/kg-8 mg/kg) or melphalan (140 mg/m 2 ) plus fludarabine. Serotherapy consisted of alemtuzumab (54 mg/m 2 ) or ATG (8 mg/kg) [3]. …”

Section: Methodsmentioning

confidence: 99%

“…In alloHCT recipients, advances in methods of donor selection, graft-versus-host disease (GVHD) management, and molecular monitoring for infectious organisms have resulted in improved overall survival (OS) [3–7]. Despite these advances, infectious complications, particularly viral infections, remain a significant cause of morbidity and mortality after alloHCT.…”

Section: Introductionmentioning

confidence: 99%

Risk Factors and Utility of a Risk-Based Algorithm for Monitoring Cytomegalovirus, Epstein-Barr Virus, and Adenovirus Infections in Pediatric Recipients after Allogeneic Hematopoietic Cell Transplantation

Rustia

Violago

Jin

et al. 2016

Self Cite

Infectious complications, particularly viral infections, remain a significant cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (alloHCT). Only a handful of studies in children have analyzed the risks for and impact of viremia on alloHCT-related outcomes. We conducted a retrospective study of 140 pediatric patients undergoing alloHCT to investigate the incidence of and risk factors for cytomegalovirus (CMV), adenovirus (ADV), and Epstein-Barr virus (EBV) viremia and viral disease after alloHCT. Furthermore, we assessed the impact of viremia on days of hospitalization and develop an algorithm for routine monitoring of viremia. Patients were monitored before alloHCT and then weekly for 180 days after alloHCT. Patients were considered to have viremia if CMV were > 600 copies/mL, EBV were > 1000 copies/mL, or ADV were > 1000 copies/mL on 2 consecutive PCRs. The overall incidences of viremia and viral disease in all patients from day 0 to +180 after alloHCT were 41.4% (n = 58) and 17% (n = 24), respectively. The overall survival for patients with viremia and viral disease was significantly lower compared with those without viremia (58% versus 74.2%, P = .03) and viral disease (48.2% versus 71.2%, P = .024). We identified that pretransplantation CMV risk status, pre-alloHCT viremia, and use of alemtuzumab were associated with the risk of post-alloHCT viremia. The average hospitalization days in patients with CMV risk (P = .011), viremia (P = .024), and viral disease (P = .002) were significantly higher. The algorithm developed from our data can potentially reduce viral PCR testing by 50% and is being studied prospectively at our center. Improved preventative treatment strategies for children at risk of viremia after alloHCT are needed.