Abstract Prolonged neutrophil recovery during acute lymphoblastic leukemia (ALL) treatment increases infection risk and delays chemotherapy. Emerging evidence implicates the gut microbiota in neutrophil reconstitution after chemotherapy. We explored the interplay between the gut microbiota and neutrophil dynamics, including neutrophil chemoattractants, in 51 children with newly-diagnosed ALL. Daily absolute neutrophil count (ANC), weekly plasma chemokines (CXCL1 and CXCL8), granulocyte colony-stimulating factor (G-CSF), and fecal samplings were monitored until day 29 during ALL induction treatment. Fecal sequencing by 16S rRNA revealed an overall significant reduction in bacterial diversity and Enterococcus overgrowth throughout the induction treatment. Prolonged neutropenia (ANC < 0.5x109 cells/L at day 36) and elevated chemokines levels were associated with decreased abundance of genera from the Ruminococcaceae and Lachnospiraceae families, decreased Veillonella genus, and Enterococcus overgrowth from diagnosis and throughout induction treatment. G-CSF was upregulated in response to neutropenia but unrelated to microbiota changes. Overall, this study reveals that diminished abundance of specific intestinal commensals and Enterococcus overgrowth are associated with delayed neutrophil reconstitution and increased chemokine signaling. These findings enhance our understanding of the mechanisms behind the huge variability in neutrophil reconstitution post-chemotherapy, emphasizing the need for gut microbiota-sparing strategies to minimize the impact of gut dysbiosis on immune recovery.
Allogeneic hematopoietic stem cell transplantation (HSCT) is challenged by acute non-infectious toxicities, including sinusoidal obstruction syndrome (SOS), engraftment syndrome (ES) and capillary leak syndrome (CLS) among others. These complications are thought to be driven by a dysfunctional vascular endothelium, but the pathophysiological mechanisms remain incompletely understood, and the diagnoses are challenged by purely clinical diagnostic criteria that are partly overlapping, limiting the possibilities for progress in this field. There is, however, increasing evidence suggesting that these challenges may be met through the development of diagnostic biomarkers to improve diagnostic accuracy of pathogenetically homogenous entities, improved pre-transplant risk assessment and the early identification of patients with increased need for specific treatment. Soluble vascular endothelial growth factor receptor-1 (sVEGF-R1) is emerging as an important biomarker of endothelial damage in patients with trauma and sepsis but has not been studied in HSCT.
Abstract Background Early‐onset osteoporosis is a frequent late effect after pediatric hematopoietic stem cell transplantation (HSCT). It remains unknown if physical training can improve bone formation in these patients, as the transplantation procedure may cause sustained dysregulation of the bone‐forming osteoblast progenitor cells. Objective We aimed to explore the effect of resistance training on bone remodeling in long‐term survivors of pediatric HSCT. Procedure In this prospective, controlled intervention study, we included seven HSCT survivors and 15 age‐ and sex‐matched healthy controls. The participants completed a 12‐week heavy load, lower extremity resistance training intervention with three weekly sessions. We measured fasting serum levels of the bone formation marker “N‐terminal propeptide of type I procollagen” (P1NP), and the bone resorption marker “C‐terminal telopeptide of type I collagen” (CTX). The hypothesis was planned before data collection began. The trial was registered at Clinicaltrials.gov before including the first participant, with trial registration no. NCT04922970. Results Resistance training led to significantly increased levels of fasting P1NP in both patients (from 57.62 to 114.99 ng/mL, p = .03) and controls (from 66.02 to 104.62 ng/mL, p < .001). No significant changes in fasting CTX levels were observed. Conclusions Despite previous high‐dose cytotoxic therapy, long‐term survivors of pediatric HSCT respond to resistance training with improvement of bone formation, comparable to that of healthy controls. This suggests that resistance training might be a promising non‐pharmacological approach to prevent the early decline in bone mass, and should be considered as part of a follow‐up program to counteract long‐term sequela after pediatric HSCT.
Patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) are challenged by cytotoxic effects of the conditioning regimen, resulting in tissue damage, systemic inflammation, and increased metabolic demands for amino acids to regenerate damaged tissues, reconstitute hematopoietic cells, and establish antioxidant defenses. To date, few studies have addressed the role of plasma amino acid (PAA) levels during transplantation, and it remains unknown if amino acid deficiency can aggravate treatment-related morbidity. We determined plasma levels of the 23 human amino acids in 80 HSCT recipients (age 1.1 to 55.4 years) before conditioning and on days +7 and +21 post-transplant along with C-reactive protein (CRP) and IL-6 levels on day +7. Significant changes were observed in plasma concentrations of several human amino acids during HSCT. On day +7, numerous amino acids were inversely correlated with both CRP and IL-6, including glutamic acid, serine, alanine, glutamine, arginine, cysteine, glycine, histidine, lysine, tryptophan, threonine, taurine, proline, and methionine (r = -.22 to -.66; all P < .05). Patients who developed sinusoidal obstruction syndrome (SOS) had significantly lower mean total PAA levels compared with patients without SOS (2013 ng/L [95% confidence interval (CI), 1709 to 2318 ng/L] versus 2706 ng/L [95% CI, 2261 to 3150 ng/L]; P = .006), along with lower individual levels of glutamic acid, serine, arginine, glycine, lysine, valine, tryptophan, threonine, and proline on day +7 (all P < .05). Patients with severe acute graft-versus-host disease had a lower mean total PAA level (1922 ng/L [95% CI, 1738 to 2106 ng/L] versus 2649 ng/L [95% CI, 2244 to 3055 ng/L]; P = .014) and lower levels of serine, glutamine, cysteine, glycine, lysine, and threonine on day +7 (all P < .05). These results indicate a relationship between low concentrations of certain amino acids and the risk of treatment-related complications.
Delayed neutrophil recovery during acute lymphoblastic leukemia (ALL) treatment increases risk of infection and causes delay in chemotherapy. Emerging evidence implicates the gut microbiota in neutrophil reconstitution after chemotherapy. We explored the interplay between the gut microbiota and neutrophil dynamics, including neutrophil chemoattractants, in 51 children with newly-diagnosed ALL. Daily absolute neutrophil count (ANC), weekly plasma chemokines (CXCL1 and CXCL8), granulocyte colony-stimulating factor (G-CSF), and fecal samplings were monitored until day 29 during ALL induction treatment. Fecal sequencing by 16S rRNA revealed an overall significant reduction in bacterial diversity and Enterococcus overgrowth throughout the induction treatment. Prolonged neutropenia (ANC<0.5x109 cells/L at day 36) and elevated chemokines levels were associated with decreased abundance of genera from the Ruminococcaceae and Lachnospiraceae families, decreased Veillonella genus, and Enterococcus overgrowth from diagnosis and throughout induction treatment. G-CSF was upregulated in response to neutropenia but unrelated to microbiota changes. Overall, this study reveals that diminished abundance of specific intestinal commensals and Enterococcus overgrowth are associated with delayed neutrophil reconstitution and increased chemokine signaling, indicating that disruption of the microbiota may contribute to prolonged neutropenia. These findings lay the groundwork for future investigations into the mechanisms behind these associations and their clinical implications for developing gut-sparring strategies to minimize the impact of gut dysbiosis on immune recovery.
Abstract Severe intestinal mucositis (IM) increases the risk of bloodstream infections (BSI) and inflammatory toxicity during acute lymphoblastic leukaemia (ALL) induction treatment. However, the implications of IM in subsequent ALL therapy phases after achieving remission remain unknown. This study investigated the relationship between IM (measured by plasma citrulline and the chemokine CCL20) and the development of BSI and systemic inflammation (reflected by C‐reactive protein, CRP) in children with ALL during high‐dose methotrexate (HDMTX) treatment, an important part of ALL consolidation therapy. The study compared patients treated according to the NOPHO ALL 2008 protocol ( n = 52) and the ALLTogether1 protocol ( n = 42), both with identical HDMTX procedures but different scheduling. One week post‐HDMTX, citrulline dropped to median levels of 14.5 and 16.9 μM for patients treated according to the NOPHO ALL 2008 and ALLTogether1 protocols, respectively ( p = 0.11). In a protocol and neutrophil count‐adjusted analysis, hypocitrullinaemia (<10 μmol/L) was associated with increased odds of BSI within 3 weeks from HDMTX (OR = 26.2, p = 0.0074). Patients treated according to the NOPHO ALL 2008 protocol exhibited increased mucosal‐ and systemic inflammation post‐HDMTX compared to patients treated according to ALLTogether1, with increased CCL20 (14.6 vs. 3.7 pg/mL, p < 0.0001) and CRP levels (10.0 vs. 1.0 mg/L, p < 0.0001). Both citrulline and CCL20 correlated with CRP for these patients ( r s = −0.44, p = 0.0016 and r s = 0.35, p = 0.016, respectively). These results suggest that hypocitrullinaemia following HDMTX increases the risk of BSI, confirming previous observations from more intensive treatments. Moreover, these data indicate that the patients' vulnerability to mucositis and inflammatory toxicity after chemotherapy varies with treatment protocol.
ABSTRACT Diagnosing acute graft‐versus‐host disease (aGvHD) following allogeneic hematopoietic stem cell transplantation (HSCT) is challenging due to heterogeneity in interpreting current clinical criteria. Recently, the Mount Sinai Acute GvHD International Consortium (MAGIC) criteria were introduced to improve diagnostic consistency. In a study of 117 pediatric patients undergoing HSCT, the modified Glucksberg and the MAGIC criteria were retrospectively compared. The MAGIC criteria identified significantly more cases of gastrointestinal (GI) aGvHD and increased overall severity, important for guiding systemic treatment. Diagnosing upper GI aGvHD based solely on symptomatology (MAGIC) proved difficult, suggesting a need for stricter definitions. For lower GI aGvHD, the modifications were clearly beneficial, although diarrhea duration remains unspecified.
