Plasma citrulline as a biomarker for enterocyte integrity in pediatric blood and BMT

Citrulline and kynurenine to tryptophan ratio: potential EED (environmental enteric dysfunction) biomarkers in acute watery diarrhea among children in Bangladesh

Two emerging biomarkers of environmental enteric dysfunction (EED) include plasma citrulline (CIT), and the kynurenine (KYN): tryptophan (TRP)/ (KT) ratio. We sought to investigate the plasma concentration of CIT and KT ratio among the children having dehydrating diarrhea and examine associations between concentrations of CIT and KT ratio with concurrent factors. For this analysis, we used cross-sectional data from a total of 102, 6-36 months old male children who suffered from non-cholera acute watery diarrhea and had some dehydration admitted to an urban diarrheal hospital, in Bangladesh. CIT, TRP, and KYN concentrations were determined at enrollment from plasma samples using ELIZA. At enrollment, the mean plasma CIT concentration was 864.48 ± 388.55 µmol/L. The mean plasma kynurenine, tryptophan concentrations, and the KT ratio (× 1000) were 6.93 ± 3.08 µmol/L, 33.44 ± 16.39 µmol/L, and 12.12 ± 18.10, respectively. With increasing child age, KYN concentration decreased (coefficient: - 0.26; 95%CI: - 0.49, - 0.04; p = 0.021); with increasing lymphocyte count, CIT concentration decreased (coef.: - 0.01; 95% CI: - 0.02,0.001, p = 0.004); the wasted child had decreased KT ratio (coef.: - 0.6; 95% CI: - 1.18, - 0.02; p = 0.042) after adjusting for potential covariates. The CIT concentration was associated with blood neutrophils (coef.: 0.02; 95% CI: 0.01, 0.03; p < 0.001), lymphocytes (coef.: - 0.02; 95% CI: - 0.03, - 0.02; p < 0.001) and monocyte (coef.: 0.06; 95% CI: 0.01, 0.11; p = 0.021); KYN concentration was negatively associated with basophil (coef.: - 0.62; 95% CI: - 1.23, - 0.01; p = 0.048) after adjusting for age. In addition, total stool output (gm) increased (coef.: 793.84; 95% CI: 187.16, 1400.52; p = 0.011) and also increased duration of hospital stay (hour) (coef.: 22.89; 95% CI: 10.24, 35.54; p = 0.001) with increasing CIT concentration. The morphological changes associated with EED may increase the risk of enteric infection and diarrheal disease among children. Further research is critically needed to better understand the complex mechanisms by which EED biomarkers may impact susceptibility to dehydrating diarrhea in children.

Nutritional challenges in children with primary immunodeficiencies undergoing hematopoietic stem cell transplant

Nutritional profile and management of patients with primary immunodeficiencies (PID) undergoing hematopoietic stem cell transplant (HSCT) has not been described in the literature. We aim to report the nutritional challenges and practices peculiar to this population before and after HSCT and suggest clinical pathways for their management. We conducted a single-centre retrospective study. Inclusion criteria were children aged less than 20 years with a diagnosis of PID who have undergone HSCT at the Royal Children's Hospital Melbourne since April 2014 with a minimal follow-up of 1 year. Nutritional parameters were collected in the pre-transplant period, at conditioning, and at 1, 3, 6 and 12 months post-HSCT. Descriptive analysis were used. Between April 2014 and December 2018, 27 children received 31 HSCT. Before transplant, 33% had a weight and/or height ≤ -2 standard deviations (SD). Forty percent required nutritional support before transplant: 33% had enteral nutrition (EN) while 7% required long-term parenteral nutrition (PN) due to intestinal failure. After transplant, although most children were started on EN, 82% required PN with a mean duration of 67 days. Mean time to full oral diet was 154 days. Pre-transplant mean weight and height were -0.57 SD and -0.88 SD respectively. After a decrease in anthropometric parameters the first 3 months post-transplant, progressive catch up was noticeable for weight (-0.27 SD) with no catch up for height at 1 year (-0.93 SD). Our work highlights the nutritional challenges and specificities of children with PID in the peri-transplant period. An approach to nutrition assessment and management in the pre- and post-transplant period is proposed.