Classical and Alternative Pathways of the Renin-Angiotensin-Aldosterone System in Regulating Blood Pressure in Hypertension and Obese Adolescents.

Primary hypertension (PH) is the leading form of arterial hypertension (AH) in adolescents. Hypertension is most common in obese patients, where 20 to 40% of the population has elevated blood pressure. One of the most effective mechanisms for regulating blood pressure is the renin-angiotensin-aldosterone system (RAAS). The new approach to the RAAS talks about two opposing pathways between which a state of equilibrium develops. One of them is a classical pathway, which is responsible for increasing blood pressure and is represented mainly by the angiotensin II (Ang II) peptide and, to a lesser extent, by angiotensin IV (Ang IV). The alternative pathway is responsible for the decrease in blood pressure and is mainly represented by angiotensin 1-7 (Ang 1-7) and angiotensin 1-9 (Ang 1-9). Our research study aimed to assess changes in angiotensin II, angiotensin IV, angiotensin 1-7, and angiotensin 1-9 concentrations in the plasma of adolescents with hypertension, with hypertension and obesity, and obesity patients. The Ang IV concentration was lower in hypertension + obesity versus control and obesity versus control, respectively p = 0.01 and p = 0.028. The Ang 1-9 concentration was lower in the obesity group compared to the control group (p = 0.036). There were no differences in Ang II and Ang 1-7 peptide concentrations in the hypertension, hypertension and obesity, obesity, and control groups. However, differences were observed in the secondary peptides, Ang IV and Ang 1-9. In both cases, the differences were related to obesity.

Lipoprotein(a)-60 Years Later-What Do We Know?

Lipoprotein(a) (Lp(a)) molecule includes two protein components: apolipoprotein(a) and apoB100. The molecule is the main transporter of oxidized phospholipids (OxPL) in plasma. The concentration of this strongly atherogenic lipoprotein is predominantly regulated by the LPA gene expression. Lp(a) is regarded as a risk factor for several cardiovascular diseases. Numerous epidemiological, clinical and in vitro studies showed a strong association between increased Lp(a) and atherosclerotic cardiovascular disease (ASCVD), calcific aortic valve disease/aortic stenosis (CAVD/AS), stroke, heart failure or peripheral arterial disease (PAD). Although there are acknowledged contributions of Lp(a) to the mentioned diseases, clinicians struggle with many inconveniences such as a lack of well-established treatment lowering Lp(a), and common guidelines for diagnosing or assessing cardiovascular risk among both adult and pediatric patients. Lp(a) levels are different with regard to a particular race or ethnicity and might fluctuate during childhood. Furthermore, the lack of standardization of assays is an additional impediment. The review presents the recent knowledge on Lp(a) based on clinical and scientific research, but also highlights relevant aspects of future study directions that would approach more suitable and effective managing risk associated with increased Lp(a), as well as control the Lp(a) levels.

Prevention and Health Benefits of Prebiotics, Probiotics and Postbiotics in Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) is the most common type of leukemia in children, comprising 75-85% of cases. Aggressive treatment of leukemias includes chemotherapy and antibiotics that often disrupt the host microbiota. Additionally, the gut microbiota may play a role in the development and progression of acute leukemia. Prebiotics, probiotics, and postbiotics are considered beneficial to health. The role of prebiotics in the treatment and development of leukemia is not well understood, but inulin can be potentially used in the treatment of leukemia. Some probiotic bacteria such as Lactobacillus shows anticancer activity in in vitro studies. Additionally, Bifidobacterium spp., as a consequence of the inhibition of growth factor signaling and mitochondrial-mediated apoptosis, decrease the proliferation of cancer cells. Many bacterial metabolites have promising anticancer potential. The available research results are promising. However, more research is needed in humans, especially in the child population, to fully understand the relationship between the gut microbiota and acute leukemia.

Endogenous Opioids in Crohn's Disease.

Caring for patients with Crohn's disease (CD) is a serious challenge in modern medicine. The increasing incidence of CD among adolescents and the severe course of the disease create the need for new methods of diagnosis and therapy. Endogenous opioids are a group of low molecular weight chemical compounds with analgesic and anti-inflammatory properties. Endorphins, enkephalins, and dynorphins may have potentially beneficial effects on the course of CD. Previous research data on this topic are inconsistent. Some authors have reported an increase in the concentration of leukocytes during the course of inflammatory bowel disease (IBD) while others have described a downward trend, explained by DPP-IV enzyme activity. Even fewer data are available on plasma endo-opioid level. There is also a lack of comprehensive studies that have assessed the endo-opioid system in patients with IBD. Therefore, the objective of this study was to measure the serum concentrations of human ß-endorphin, human proenkephalin (A), and human big dynorphin in CD patients in the acute phase of the disease, during hospital treatment, and in the remission state. All determinations were performed using ELISA kits. The results of our study showed that the concentrations of all the tested endo-opioids, especially ß-endorphin and proenkephalin (A), were reduced in adolescents with CD compared to those in the healthy control group, during the acute phase of the disease, and in the remission state. Modulation of the endogenous opioid system and the use of selective nonnarcotic agonists of opioid receptors seems to be promising goals in the future treatment of CD.

Prebiotics, Probiotics, and Postbiotics in the Prevention and Treatment of Anemia.

Iron deficiency anemia (IDA) is very common and affects approximately 1/3 of the world's human population. There are strong research data that some probiotics, such as Lactobacillus acidophilus and Bifidobacterium longum improve iron absorption and influence the course of anemia. Furthermore, prebiotics, including galactooligosaccharides (GOS) and fructooligosaccharides (FOS), increase iron bioavailability and decrease its destructive effect on the intestinal microbiota. In addition, multiple postbiotics, which are probiotic metabolites, including vitamins, short-chain fatty acids (SCFA), and tryptophan, are involved in the regulation of intestinal absorption and may influence iron status in humans. This review presents the actual data from research studies on the influence of probiotics, prebiotics, and postbiotics on the prevention and therapy of IDA and the latest findings regarding their mechanisms of action. A comparison of the latest research data and theories regarding the role of pre-, post-, and probiotics and the mechanism of their action in anemias is also presented and discussed.

Irisin concentration in infant formulas and breast milk.

BACKGROUND: Irisin is a newly discovered myokine with antiobesity properties. The delivery of irisin with the breast milk or formula is an emerging concept that myokine present at human milk influences postnatal energy balance and developmental parameters. The aim of the study was to evaluate irisin concentration in breast milk of mothers with term and preterm babies and in infant formulas. METHODS: A total of 49 lactating mothers were enrolled in the study: 31 mothers of very low birth weight preterm infants and 18 mothers of term infants. Milk samples were collected twice: during the first week after delivery and after 4 weeks of delivery. Irisin concentration was determined using ELISA kits both in human milk and in samples of 14 different infant formulas. RESULTS: There were no differences in milk irisin levels between preterm and full-term milk samples during both the 1st and the 4th week after delivery. There were also no differences in irisin concentration between transitional milk and mature milk in both tested groups. Irisin concentrations in preterm and full-term milk were significantly higher than in formulas for 30 days period after delivery. A significant increase of irisin concentration in natural milk 4 weeks postdelivery in comparison to 1st week after delivery was observed (mean difference 0.362 µg/mL; P=0.0063). CONCLUSIONS: This study provides evidence that irisin is present in infant formulas, although in less amount than in human milk. Further research is needed to assess, if children fed with infant formulas may disadvantage from lower irisin supply.

A New Perspective on the Renin-Angiotensin System.

Cardiovascular disease (CVD) is the leading cause of death in the world. Hypertension is a serious medical problem not only in adults but also in children and adolescents. The renin-angiotensin-aldosterone system (RAAS) is one of the most important mechanisms regulating blood pressure and the balance of water and electrolytes. According to the latest reports, RAAS acts not only on endocrine but also on paracrine, autocrine, and intracrine. Moreover, RAAS has a component associated with hypotension and cardioprotective effects. These components are called alternative pathways of RAAS. The most important peptide of the alternative pathway is Ang 1-7, which is related to the Mas receptor. Mas receptors have widely known antihypertension properties, including vasodilatation, the release of nitric oxide, and increased production of anti-inflammatory cytokines. Another interesting peptide is angiotensin A, which combines the properties of the classical and alternative pathways. No less important components of RAAS are the proteolytic enzymes angiotensin convertase enzyme type 1 and 2. They are responsible for the functioning of the RAAS system and are a hypertension therapeutic target. Also involved are tissue-specific enzymes that form a local renin-angiotensin system. Currently, a combination of drugs is used in hypertension treatment. These drugs have many undesirable side effects that cannot always be avoided. For this reason, new treatments are being sought, and the greatest hope comes from the ACE2/ang 1-7/MasR axis.

Prebiotics, Probiotics, Synbiotics, Paraprobiotics and Postbiotic Compounds in IBD.

The increasing incidence of inflammatory bowel diseases (IBD) and the increasing severity of the course of these diseases create the need for developing new methods of therapy. The gut microbiome is extensively studied as a factor influencing the development and course of IBD. The composition of intestinal microbiota can be relatively easily modified by diet (i.e., prebiotics, mainly dietary fibers) and bacterial supplementation using beneficial bacteria strains called probiotics. Additionally, the effects of the improved microbiome could be enhanced or gained by using paraprobiotics (non-viable, inactivated bacteria or their components) and/or postbiotics (products of bacterial metabolism or equal synthetic products that beneficially modulate immunological response and inflammation). This study summarizes the recent works on prebiotics, probiotics, synbiotics (products merging pre- and probiotics), paraprobiotics and postbiotics in IBD.

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.

FTO and PLAG1 Genes Expression and FTO Methylation Predict Changes in Circulating Levels of Adipokines and Gastrointestinal Peptides in Children.

Adipokines and gastrointestinal tract hormones are important metabolic parameters, and both epigenetic factors and differential gene expression patterns may be associated with the alterations in their concentrations in children. The function of the FTO gene (FTO alpha-ketoglutarate dependent dioxygenase) in the regulation of the global metabolic rate is well described, whereas the influence of protooncogene PLAG1 (PLAG1 zinc finger) is still not fully understood. A cross-sectional study on a group of 26 children with various BMI values (15.3-41.7; median 28) was carried out. The aim was to evaluate the dependencies between the level of methylation and expression of aforementioned genes with the concentration of selected gastrointestinal tract hormones and adipokines in children. Expression and methylation were measured in peripheral blood mononuclear DNA by a microarray technique and a restriction enzyme method, respectively. All peptide concentrations were determined using the enzyme immunoassay method. The expression level of both FTO and PLAG1 genes was statistically significantly related to the concentration of adipokines: negatively for apelin and leptin receptor, and positively for leptin. Furthermore, both FTO methylation and expression negatively correlated with the concentration of resistin and visfatin. Cholecystokinin was negatively correlated, whereas fibroblast growth factor 21 positively correlated with methylation and expression of the FTO gene, while FTO and PLAG1 expression was negatively associated with the level of cholecystokinin and glucagon-like peptide-1. The PLAG1 gene expression predicts an increase in leptin and decrease in ghrelin levels. Our results indicate that the FTO gene correlates with the concentration of hormones produced by the adipose tissue and gastrointestinal tract, and PLAG1 gene may be involved in adiposity pathogenesis. However, the exact molecular mechanisms still need to be clarified.

The role of complementary and alternative methods in the treatment of pain in patients with cancer - current evidence and clinical practice: a narrative review.

INTRODUCTION: Pain related to cancer, despite the numerous treatment options available, is still a challenge in contemporary pain medicine. The unsatisfactory treatment of cancer pain is one of the main reasons why patients seek complementary and alternative methods (CAM) and a more integrative/holistic approach to pain management. The popularity of CAM forces healthcare professionals to provide patients with current and evidence-based information on the effectiveness and safety of CAM. The aim of the paper is to present current evidence and limitations regarding CAM commonly used in the pain management of cancer patients. MATERIAL AND METHODS: The paper comprehensively reviews the current and most relevant literature considering the integrative approach to management of pain due to cancer disease and/or cancer treatment. RESULTS: The available data from clinical trials, meta-analyses, and systematic reviews supports the effectiveness of acupuncture, massage, physical exercises, music therapy, and mind-body therapies as adjunct therapies for alleviating pain in cancer patients, although the supporting evidence is weak or moderate. CONCLUSIONS: Based on the available knowledge, physicians should be capable of advising the cancer patient as to which CAM methods can be used safely, which are contraindicated, and what therapeutic effects they may expect, especially when standard pain treatment fails or induces serious side effects. An integrative approach to cancer pain management may improve the quality of pain treatment, patients' quality of life, and satisfaction with pain relief.

Plasma elafin, cathelicidin, and α-defensins are increased in paediatric inflammatory Crohn's disease and reflect disease location.

INTRODUCTION: The aim of our study was to assess antimicrobial peptides in children with Crohn's disease (CD). METHODS: Plasma elafin, cathelicidin, and α- and ß-defensins were assessed in 35 children with CD using immunoassays. Phenotype and location of CD were assessed based on the results of endoscopic and radiological studies. RESULTS: We found increased elafin, cathelicidin, and α-defensins in children with inflammatory phenotype as compared to stricturing and penetrating phenotypes of CD. Additionally, we found increased elafin and cathelicidin in colonic location and α-defensins in ileal CD locations. CONCLUSIONS: Assessing antimicrobial peptides may be helpful in estimating of phenotype and location of CD lesions.

The Insight into Insulin-Like Growth Factors and Insulin-Like Growth-Factor-Binding Proteins and Metabolic Profile in Pediatric Obesity.

Insulin-like growth factors (IGFs) and insulin-like growth-factor-binding proteins (IGFBPs) regulate cell proliferation and differentiation and may be of importance in obesity development. The aim of the study was to analyze the expression of chosen IGF-axis genes and the concentration of their protein products in 28 obese children (OB) and 34 healthy control (HC), and their correlation with essential parameters associated with childhood obesity. The gene expression of IGFBP7 was higher, and the expression of IGF2 and IGFBP1 genes was lower in the OB. The expression of IGFBP6 tended to be lower in OB. IGFBP4 concentration was significantly higher, and IGFBP3 tended to be higher in the OB compared to the HC, while IGFBP1, IGFBP2, and IGFBP6 were significantly lower, and IGFBP7 tended to be lower in OB. We found numerous correlations between IGFs and IGFBP concentration and obesity metabolic parameters. IGFBP6 correlated positively with apelin, cholecystokinin, glucagone-like peptide-1, and leptin receptor. These peptides were also significantly lower in obese children in our study. The biological role of decreased levels of IGFBP6 in obese children needs further investigation.

The Expression of Genes Related to Lipid Metabolism and Metabolic Disorders in Children before and after Hematopoietic Stem Cell Transplantation-A Prospective Observational Study.

Metabolic disorders in children after hematopoietic stem cell transplantation (HSCT) are poorly characterized. However, it is known that dyslipidemia and insulin resistance are particularly common in these patients. We conducted a prospective study of 27 patients treated with HSCT to assess the possibility of predicting these abnormalities. We measured gene expressions using a microarray technique to identify differences in expression of genes associated with lipid metabolism before and after HSCT. In patients treated with HSCT, total cholesterol levels were significantly higher after the procedure compared with the values before HSCT. Microarray analysis revealed statistically significant differences in expressions of three genes, DPP4, PLAG1, and SCD, after applying the Benjamini-Hochberg procedure (pBH < 0.05). In multiple logistic regression, the increase of DPP4 gene expression before HCST (as well as its change between pre- and post-HSCT status) was associated with dyslipidemia. In children treated with HSCT, the burden of lipid disorders in short-term follow-up seems to be lower than before the procedure. The expression pattern of DPP4 is linked with dyslipidemia after the transplantation.

Methylation and Expression of FTO and PLAG1 Genes in Childhood Obesity: Insight into Anthropometric Parameters and Glucose-Lipid Metabolism.

The occurrence of childhood obesity is influenced by both genetic and epigenetic factors. FTO (FTO alpha-ketoglutarate dependent dioxygenase) is a gene of well-established connection with adiposity, while a protooncogene PLAG1 (PLAG1 zinc finger) has been only recently linked to this condition. We performed a cross-sectional study on a cohort of 16 obese (aged 6.6-17.7) and 10 healthy (aged 11.4-16.9) children. The aim was to evaluate the relationship between methylation and expression of the aforementioned genes and the presence of obesity as well as alterations in anthropometric measurements (including waist circumference (WC), body fat (BF_kg) and body fat percent (BF_%)), metabolic parameters (lipid profile, blood glucose and insulin levels, presence of insulin resistance) and blood pressure. Expression and methylation were measured in peripheral blood mononuclear cells using a microarray technique and a method based on restriction enzymes, respectively. Multiple regression models were constructed to adjust for the possible influence of age and sex on the investigated associations. We showed significantly increased expression of the FTO gene in obese children and in patients with documented insulin resistance. Higher FTO expression was also associated with an increase in WC, BF_kg, and BF_% as well as higher fasting concentration of free fatty acids (FFA). FTO methylation correlated positively with WC and BF_kg. Increase in PLAG1 expression was associated with higher BF%. Our results indicate that the FTO gene is likely to play an important role in the development of childhood adiposity together with coexisting impairment of glucose-lipid metabolism.

The effect of disinfecting procedure on the glucose concentration using a personal glucose meter.

BACKGROUND: Personal glucose meters, primarily designed for self-control of glucose concentration in patients with diabetes, are frequently used in clinical practice as point-of-care equipment. The procedure of washing hands with water and soap before testing, as recommended by the manufacturer of personal glucose meters, in hospital wards is often difficult to fulfil and is replaced by disinfecting the place of blood sampling with isopropyl alcohol. AIM: The purpose of the research was to evaluate the effect of different disinfecting procedures on glycemia measurement in capillary blood using personal glucose meters. MATERIALS AND METHODS: Four measurements of glycemia were taken in each of 50-volunteer group using Accu-Check Performa (Roche, Swiss) glucose meter using different procedures: washing hands with soap and drying them (1), disinfection with isopropyl alcohol and waiting for the disinfectant to evaporate (2) and the immediate puncture after disinfection. In the latter case two kind of single-use lancets were use - typical for adult (3) and smaller preferred by diabetics or children (4). RESULTS: Paired T-student test showed no statistically significant difference between measurements 1st and 2nd 95% CI (-4.282 to 0.322), p = 0.09. However, the comparison between 1st/3rd and 1st/4th showed statistically significant difference, 95% CI (-4.964 to -0.796), p = 0,0077 (p < 0,01) and 95% CI (-7.842 to -2.917), p = 0.00006 (p < 0.001). CONCLUSIONS: The procedure of disinfection when fluid completely evaporates has no effect on glucose measurements. Sampling the wet finger influences results of glucose measurement but observed changes were clinically irrelevant.

Effect of Selected Factors on the Serum 25(OH)D Concentration in Women Treated for Breast Cancer.

Maintaining an optimal vitamin D concentration reduces the risk of recurrence and extends survival time in patients after breast cancer treatment. Data on vitamin D deficiency among Polish women after breast cancer therapy are limited. Thus, the aim of the study was the analysis of vitamin D status in post-mastectomy patients, considering such factors as seasons, social habits, vitamin D supplementation and its measurements. The study involved 94 women after breast cancer treatment. Serum vitamin D concentration was measured, and a questionnaire, gathering demographic and clinical data regarding cancer, diet, exposure to sun radiation, and knowledge of recommendations on vitamin D supplementation, was delivered twice, in both winter and in summer. The control group consisted of 94 age-matched women with no oncological history. In women after breast cancer treatment, 25-hydroxyvitamin D (25(OH)D) deficiency was much more frequent than in the general population. Only about half of the patients supplemented vitamin D at the beginning of the study. After the first test and the issuing of recommendations on vitamin D supplementation, the percentage of vitamin D supplemented patients increased by about 30% in study groups. The average dose of supplement also increased. None of the women that were not supplementing vitamin D and were tested again in winter had optimal 25(OH)D concentration. It was concluded that vitamin deficiency is common in women treated for breast cancer. Medical advising about vitamin D supplementation and monitoring of 25(OH)D concentration should be improved.

Serum concentrations of fibrosis markers in children with inflammatory bowel disease.

BACKGROUND AND STUDY AIMS: The aim of the study was to assess the usefulness of serum concentrations of YKL-40/ CHI3L1 (a 40-kilodalton glycoprotein also referred to as chitinase 3 like- 1 - CHI3L1) and PIIINP (N-terminal propeptide of type III procollagen), markers of fibrosis, in the monitoring of inflammatory processes and fibrosis in children with inflammatory bowel disease (IBD). PATIENTS AND METHODS: In 60 patients (41 with Crohn's disease (CD), 19 with ulcerative colitis (UC)) concentrations of investigated parameters were measured at baseline (day 0), after 3 and after 6-8 weeks of pharmacological treatment. RESULTS: PIIINP concentrations were significantly higher in CD patients compared to UC (baseline results: median concentrations 1013.73 vs 78.30 ng/mL; P = 0.06 for the Kruskall-Wallis test; results at 6-8 weeks: 1076.48 vs 53.10 ng/mL, P = 0.01). Fibrosis was clearly present in patients with CD and its severity increased (reflected by both YKL-40/ CHI3L1 and PIIINP concentrations) in 6-8 weeks of follow up, regardless of the treatment used during that time. In patients with UC the levels of YKL-40/CHI3L1 and PIIINP were lower at baseline and further decreased after 6-8 weeks (median concentrations were respectively: 39.5 ng/mL vs 24.7 ng/mL and 78.3 ng/mL vs 53.1 ng/mL). CONCLUSION: Fibrosis was more severe in CD than in UC patients. The marker that more accurately reflected these differences was PIIINP.

Lidocaine as an element of multimodal analgesic therapy in major spine surgical procedures in children: a prospective, randomized, double-blind study.

BACKGROUND: Introducing the principles of multimodal analgesic therapy is necessary to provide appropriate comfort for the patient after surgery. The main objective of the study was evaluating the influence of perioperative intravenous (i.v.) lidocaine infusion on postoperative morphine requirements during the first 48 h postoperatively in children undergoing major spine surgery. MATERIALS AND METHODS: Prospective, randomized, double-blind study: 41 children, qualified to multilevel spine surgery, were randomly divided into two treatment groups: lidocaine and placebo (control). The lidocaine group received lidocaine as a bolus of 1.5 mg/kg over 30 minutes, followed by a continuous infusion at 1 mg/kg/h to 6 hours after surgery. The protocol of perioperative management was identical for all patients. MEASUREMENTS: morphine demand, intensity of postoperative pain (the Numerical Rating Scale), oral feeding initiation time, first attempts at assuming erect position, postoperative quality of life (the Acute Short-form /SF-12/ health survey). RESULTS: Patient data did not differ demographically. Compared to the control group, lidocaine treatment reduced the demand for morphine during the first 24h [95% CI 0.13 (0.11-0.28) mg/kg, p = 0.0122], 48h [95% CI 0.46 (0.22-0.52) mg/kg, p = 0.0299] after surgery and entire hospitalization [95% CI 0.58 (0.19-0.78) mg/kg, p = 0.04]; postoperative pain intensity; nutritional withdrawal period [introduction of liquid diet (p = 0.024) and solid diet (p = 0.012)], and accelerated the adoption of an upright position [sitting (p = 0.048); walking (p = 0.049)]. The SF-12 generic health survey did not differ between groups before operation, 2 months and 4 years after surgery. CONCLUSIONS: Perioperative lidocaine administration, as a part of the applied analgesic therapy regimen, may decrease postoperative opioid demand and accelerates convalescence of children undergoing major surgery.

Gastrointestinal peptides in children before and after hematopoietic stem cell transplantation.

BACKGROUND: Gastrointestinal tract function and it's integrity are controlled by a number of peptides whose secretion is influenced by severe inflammation. In stomach the main regulatory peptide is ghrelin. For upper small intestine cholecystokinin and lower small intestine glucagon-like peptide- 1 are secreted, while fibroblast growth factor-21 is secreted by several organs, including the liver, pancreas, and adipose tissue [12]. Hematopoietic stem cell transplantation causes serious mucosal damage, which can reflect on this peptides. METHODS: The aim of the study was to determine fasting plasma concentrations of ghrelin, cholecystokinin, glucagon- like peptide-1, and fibroblast growth factor-21, and their gene expressions, before and 6 months after hematopoietic stem cell transplantation.27 children were studied, control group included 26 healthy children. RESULTS: Acute graft versus host disease was diagnosed in 11 patients (41%, n = 27). Median pre-transplantation concentrations of gastrointestinal peptides, as well as their gene expressions, were significantly lower in studied group compared with the control group. Only median of fibroblast growth factor-21 concentration was near-significantly higher before stem cell transplantation than in the control group. The post-hematopoietic transplant results revealed significantly higher concentrations of the studied peptides (except fibroblast growth factor-21) and respective gene expressions as compare to pre transplant results. Median glucagone like peptide-1 concentrations were significantly decreased in patients with features of acute graft versus host disease. Moreover, negative correlation between glucagone like peptide-1 concentrations and acute graft versus host disease severity was found. CONCLUSIONS: Increased concentrations and gene expressions of gastrointestinal tract regulation peptides can be caused by stimulation of regeneration in the severe injured organ. Measurement of these parameters may be a useful method of assessment of severity of gastrointestinal tract complications of hematopoietic stem cell transplantation.