A Systematic Review of the Literature and Perspectives on the Role of Biomarkers in the Management of Malnutrition After Allogeneic Hematopoietic Stem Cell Transplantation

Modern views of nutritional support in patients undergoing allogeneic stem cell transplantation

Patients undergoing allogeneic stem cell transplant (HSCT) have a higher risk of developing malnutrition. The aetiology is multifactorial and complex: the conditioning regimen causes damages to the gastrointestinal tract that can contribute to trigger graft-versus-host disease and/or infectious complications that adversely affect food intake and the gut absorption of nutrients in transplant recipients. Consequently, patients might develop weight loss and muscle wasting. There is mounting evidence that insufficient muscle mass increases the risk of toxicity to many chemotherapy drugs. Furthermore, the screening for malnutrition, assessment and intervention can vary among HSCT centers. Hereby, we report the main nutritional clinical issues in the field of HSCT and the main nutritional tools used in this setting. Future clinical trials investigating nutritional tools and dose-escalating studies based on pre-treatment body composition assessment may help having the potential to alter cancer treatment paradigms.

Role of mucositis in predicting gut microbiota composition in people with cancer

PURPOSE OF REVIEW

Disruption of the precious ecosystem of micro-organisms that reside in the gut - the gut microbiota - is rapidly emerging as a key driver of the adverse side effects/toxicities caused by numerous anti-cancer agents. Although the contribution of the gut microbiota to these toxicities is understood with ever increasing precision, the cause of microbial disruption (dysbiosis) remains poorly understood. Here, we discuss current evidence on the cause(s) of dysbiosis after cancer therapy, positioning breakdown of the intestinal mucosa (mucositis) as a central cause.

RECENT FINDINGS

Dysbiosis in people with cancer has historically been attributed to extensive antibiotic use. However, evidence now suggests that certain antibiotics have minimal impacts on the microbiota. Indeed, recent evidence shows that the type of cancer therapy predicts microbiota composition independently of antibiotics. Given most anti-cancer drugs have modest effects on microbes directly, this suggests that their impact on the gut microenvironment, in particular the mucosa, which is highly vulnerable to cytotoxicity, is a likely cause of dysbiosis. Here, we outline evidence that support this hypothesis, and discuss the associated clinical implications/opportunities.

SUMMARY

The concept that mucositis dictates microbiota compositions provides two important implications for clinical practice. Firstly, it reiterates the importance of prioritising the development of novel mucoprotectants that preserve mucosal integrity, and indirectly support microbial stability. Secondly, it provides an opportunity to identify dysbiotic events and associated consequences using readily accessible, minimally invasive biomarkers of mucositis such as plasma citrulline.

The emerging role of nutritional support in the supportive care of pediatric patients undergoing hematopoietic stem cell transplantation

Allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) represents a potentially curative strategy for many oncological, hematological, metabolic, and immunological diseases in children. The continuous effort in ameliorating supportive care represents one of the cornerstones in the improvement of outcome in these patients. Nowadays, more than ever nutritional support can be considered a key feature. Oral feeding in the early post-transplant period is severely impaired because of mucositis due to conditioning regimen, characterized by, mainly by vomiting, anorexia, and diarrhea. Gastrointestinal acute graft-versus-host-disease (GvHD), infections and associated treatments, and other medications, such as opioids and calcineurin inhibitors, have also been correlated with decreased oral intake. The consequent reduction in caloric intake combined with the catabolic effect of therapies and transplantation-related complications with consequent extended immobilization, results in a rapid deterioration of nutritional status, which is associated with decreased overall survival and higher complication rates during treatment. Thus, nutritional support during the early post-transplantation period becomes an essential and challenging issue for allo-HSCT recipients. In this context, the role of nutrition in the modulation of the intestinal flora is also emerging as a key player in the pathophysiology of the main complications of HSCT. The pediatric setting is characterized by less evidence, considering the challenge of addressing nutritional needs in this specific population, and many questions are still unanswered. Thus, we perform a narrative review regarding all aspects of nutritional support in pediatric allo-HSCT recipients, addressing the assessment of nutritional status, the relationship between nutritional status and clinical outcomes and the evaluation of the nutritional support, ranging from specific diets to artificial feeding.

Impact of Allogeneic Hematopoietic Stem Cell Transplantation on Nutritional Status and Intake in Children

OBJECTIVES

This study aimed to describe the impact of allogeneic/haploidentical hematopoietic stem cell transplantation on nutritional status and intake in a group of children aged 2 to 18 years.

METHODS

In an observational study, data were collected prospectively. Patients were prescribed individual nutritional support by hospital routines. Anthropometrics were measured pre-transplant at hospital admission and weekly from the day of transplant (day 0) until day +28. z scores for weight, height, and BMI were calculated using Norwegian growth references to assess nutritional status. Pre-transplant diet was assessed on the day of hospitalization. Nutrient provision from enteral nutrition (EN = oral and tube) and parenteral nutrition (PN) was assessed by daily records from day +1 until day +28, or previous discharge, and compared with recommendations (RI) from the Nordic Nutrition Recommendations and ESPGHAN guidelines. Total energy intake was presented as the percentage (%) of basal metabolic rate (BMR) calculated by the Schofield equation. Macro- and micronutrient provisions were presented as medians (interquartile range) and the % of RI.

RESULTS

Twenty-eight patients, mean age 10.3 years (range 3.5-16.6), were included. Two-thirds (n = 18) had malignant diseases. At admission, mean weight Z-score was -0.3, height z scores -0.7, and BMI Z-score 0.1. Eighteen percent (n = 5) were stunted and 25% (n = 7) had overweight. At admission, 25% (n = 7) had established tube feeding, and 7% (n = 2) also had PN. No significant changes in weight z scores were detected during the studied weeks ( P = 0.454). The median daily energy provision was 115% (110-123) of BMR and proteins 1.5 (1.3-1.8) g/kg. EN was provided during a median of 93% of the studied days and provided 21% of the energy. PN was given on a median of 96% of the studied days and provided 79% of energy. RI for vitamins, magnesium, and zinc was met. Provision of copper, iodine, selenium, calcium, and phosphate was below RI.

CONCLUSIONS

Combined EN and PN providing 115% of BMR and 1.5 g/kg protein ensured stable weight by day +28 and covered RI, except for trace elements and minerals.

Malnutrition Prevention after Allogeneic Hematopoietic Stem Cell Transplantation (alloHSCT): A Prospective Explorative Interventional Study with an Oral Polymeric Formulation Enriched with Transforming Growth Factor Beta 2 (TGF-β2)

Malnutrition is common after allogeneic Hematopoietic Stem Cell Transplantation (alloHSCT), and interventions directed to correct nutritional status are warranted to improve transplant outcomes. In this prospective study, an oral polymeric formulation enriched with TGF-β2 (TE-OPF) was explored to correct malnutrition according to Patient-Generated Subjective Global Assessment (PG-SGA). TE-OPF was proposed to 51 consecutive patients who received transplants at our institution for hematological malignancies, and sufficient dose intake was established per protocol as at least 50% of the prescribed dose of TE-OPF: group A received adequate nutritional support; group B, inadequate. The study met the primary outcomes in terms of safety (no adverse events reported during TE-OPF intake except for its disgusting taste) and malnutrition (PG-SGA C 28 days after transplant): severely malnourished patients (PG-SGA C) accounted for 13% in group A and 88.9% in group B (p = 0.000). At the end of the study, after a median follow-up of 416 days, the estimated median Overall Survival (OS) was 734 days for well or moderately nourished patients (PG-SGA A/B) in comparison to 424 for malnourished patients (p = 0.03). Inadequate TE-OPF intake was associated with an increase in acute gastrointestinal Graft Versus Host Disease (GVHD) cumulative incidence (38% vs. 0% p = 0.006). A higher incidence of pneumonia was reported in group B (p = 0.006). IGF-1 levels at 14 and 28 days after transplant were significantly higher in group A and were associated with a lower incidence of acute GVHD (aGVHD). Higher subsets of B, T, and NK cells were found in group A, and a higher number of CD16+ NK cells was associated with a lower incidence of acute GVHD (p = 0.005) and increased survival at the end of the study (p = 0.023). Artificial neural network analysis suggested that inadequate TE-OPF intake, pneumonia, and sepsis significantly affected malnutrition 28 days after alloHSCT and survival 365 days after alloHSCT (normalized importance 100%, 82%, and 68%, respectively). In this exploratory and preliminary study, the use of TE-OPF appeared to reduce the incidence of malnutrition after alloHSCT, but larger and controlled studies are required.

Concentrations of Insulin-like Growth Factors and Insulin-like Growth Factor-Binding Proteins and Respective Gene Expressions in Children before and after Hematopoietic Stem Cell Transplantation

Insulin-like growth factors (IGF-1 and IGF-2) and insulin-like growth factor-binding proteins (IGFBP-1 to -7) are involved in the regulation of cell proliferation and differentiation and may be associated with various metabolic parameters. The aim of our study was to compare levels of IGFs and IGFBPs and the expressions of their genes in children before and after hematopoietic stem cell transplantation (HSCT) to assess their potential as markers of late metabolic complications of HSCT. We also conducted additional comparisons with healthy controls and of correlations of IGF and IGFBP levels with anthropometric and biochemical parameters. We analyzed 19 children treated with HSCT and 21 healthy controls. We found no significant differences in the levels of IGFs and IGFBPs and expressions of their genes before and after HSCT, while IGF and IGFBP levels were significantly lower in children treated with HSCT compared with controls. We conclude that our results did not reveal significant differences between the levels of IGFs and IGFBPs before and after HSCT, which would make them obvious candidates for markers of late complications of the procedure in children. However, due to the very low number of patients this conclusion must be taken with caution and may be altered by further research.

State of the art: the role of citrulline as biomarker in patients with chemotherapy- or graft-versus-host-disease-induced mucositis

PURPOSE OF REVIEW

Serum or plasma citrulline levels are used as biomarker for a broad spectrum of intestinal functions. During high-dose chemotherapy, citrulline levels are decreased due to mucositis, a common side effect of chemotherapy. This may decrease intestinal function and result in diarrhea. In this review, most recent studies investigating citrulline as biomarker for intestinal function are discussed, with focus on patients with oncological diseases, specifically hematological malignancies with chemotherapy- or Graft-versus-Host-disease (GVHD)-induced mucositis.

RECENT FINDINGS

Citrulline has recently been widely studied in relation to intestinal function and various clinical conditions. It seems therefore a promising noninvasive biomarker in clinical practice for more than intestinal function alone. The association between citrulline levels and intestinal function in patients with hematological malignancies, with or without mucositis remains unclear, as no other parameters of intestinal function for this purpose were assessed.

SUMMARY

In conclusion, citrulline seems to be a promising noninvasive biomarker for various intestinal conditions in general, and potentially for intestinal function in patients with chemotherapy- or GVHD-induced mucositis. It is unclear from recent literature whether high fecal volume or diarrhea as side effect, results in impaired intestinal function and severe malabsorption and if citrulline biomarkers can be useful to detect this.