Peri-implant diseases and systemic inflammation: A preliminary analysis from a cross-sectional survey of patients with hypertension.

BACKGROUND: The aim of this study was to investigate the association between peri-implant diseases and systemic inflammation assessed by serum C-reactive protein (CRP) levels in a sample of patients with hypertension. METHODS: A total of 151 participants with hypertension were included in a cross-sectional study. The population was divided into six groups according to their peri-implant and periodontal status (healthy controls, mucositis, peri-implantitis, periodontitis, periodontitis and mucositis, periodontitis, and peri-implantitis). Linear, logistic regression, and correlation analyses were performed. RESULTS: CRP levels were statistically significantly higher in participants with periodontitis alone (median 3.2 mg/L, interquartile range [IQR] 1.8, p = 0.012), combined with mucositis (3.10 mg/L, IQR 2.35, p < 0.001) or peri-implantitis (2.7 mg/L, IQR 2.53, p = 0.002) when compared to the healthy controls (1 mg/L, IQR 1.2). This association was independent of age, sex, smoking status, and adiposity differences. Participants with periodontitis with and without peri-implant diseases had the greatest odds of exhibiting CRP > 3 mg/L (odds ratio = 7.3, 95% confidence interval 1.6-33.9). CONCLUSIONS: Peri-implant diseases are associated with systemic inflammation, but the nature of the association should be further investigated.

Association of neutrophil-to-lymphocyte ratio with severe radiation-induced mucositis in pharyngeal or laryngeal cancer patients: a retrospective study.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) is a marker of systemic inflammation that informs clinical decisions regarding recurrence and overall survival in most epithelial cancers. Radiotherapy for head and neck cancer leads to mucositis in almost all patients and severe radiation-mucositis affects their quality of life (QOL). However, little is known about the NLR for severe mucositis. Therefore, this study aimed to show the association between the NLR and severe radiation-induced mucositis in hypopharyngeal or laryngeal cancer patients. METHODS: In this retrospective study, we determined the incidence of grade 3 mucositis in 99 patients who were receiving definitive radiotherapy or chemoradiotherapy (CRT) for hypopharyngeal or laryngeal cancer. We performed univariate and multivariate logistic regression analyses to investigate the characteristics of grade 3 mucositis. Kaplan-Meier curves and log-rank tests were used to evaluate the occurrence of grade 3 mucositis between two groups with high (NLR > 5) or low (NLR < 5) systemic inflammation. RESULTS: The incidence of grade 3 mucositis was 39%. Univariate logistic regression analysis showed that the NLR (Odd ratio [OR] = 1.09; 95% confidence interval [CI] = 1.02-1.16; p = 0.016) and smoking (OR = 1.02; 95% CI = 1.00-1.03; p = 0.048) were significantly associated with grade 3 mucositis. Multivariate logistic regression analysis showed that the NLR was independently associated with grade 3 mucositis (OR = 1.09; 95% CI = 1.01-1.17; p = 0.021). Kaplan-Meier curves also showed that patients with higher NLR (NLR > 5) prior to radiotherapy developed grade 3 mucositis more frequently than those with lower NLR during radiotherapy (p = 0.045). CONCLUSION: This study suggests that a higher NLR is a risk factor and predictor of severe radiation-induced mucositis in hypopharyngeal or laryngeal cancer patients.

Pharmacokinetics analysis results are similar for oral compared to intravenous busulfan in patients undergoing hematopoietic stem cell transplantation, except for the earlier onset of mucositis. A controlled clinical study.

Busulfan is used in myeloablative schemes for hematopoietic stem cell transplantation (HSCT), with monitoring of dosage through the area under the curve (AUC) of the drug plasma concentration (µMol min). In this study, we compared the complete pharmacokinetics of busulfan administered orally (Bu-Oral) and intravenously (Bu-IV). We evaluated 40 patients who underwent HSCT with different types of conditioning regimens. After one dose, in the Bu-Oral group (n = 21), the median AUC was 1174 µMol min (799-4000), reaching a median of 4440 µMol min (3428-7181.5) during conditioning in 24 h. In the Bu-IV group (n = 19), it was 1244.8 µMol min (1001.2-2021), reaching 5598.0 µMol min (3102-8818) during conditioning in 24 h. Measuring plasma concentration of Bu in patients undergoing HSCT is important, regardless of the formulation, and the inclusion of a pre-HSCT test can predict the optimal dose during conditioning. Pharmacokinetics of the oral administration of busulfan, as well as clearance, are extremely variable, and this can potentially compromise the clinical results of the treatment since it makes it difficult to predict clinical results.

VEGF, Microvessel Density, and CD44 as Inflammation Markers in Peri-implant Healthy Mucosa, Peri-implant Mucositis, and Peri-implantitis: Impact of Age, Smoking, PPD, and Obesity.

Several biologic processes affect the supporting peri-implant tissue leading to implant failure and complications, mainly referred to inflammation that is still poorly investigated in the peri-implant soft tissues. Our aim was to investigate in peri-implant healthy mucosa, peri-implant mucositis, and peri-implantitis the expression of some angiogenesis markers highly associated with inflammation, and evaluate its relationships with age, smoking, peri-implant pocket depth (PPD), and body max index (BMI). Moreover, we wanted to study the impact of these clinical parameters in the disease pathogenesis. Forty-eight total patients were recruited. Sixteen had at least one successfully osteointegrated dental implant (group A) and 32 had at least one osseointegrated implant in need of a peri-implant treatment for inflammatory/infectiveous reasons: precisely 16 for mucositis (group B) and 16 for peri-implantitis (group C). VEGF, CD34, and CD44 immunohistochemical expression was evaluated in the interproximal biopsies of marginal peri-implant tissue and correlated with the clinical parameters. A significant difference between groups in mean PPD was found, while the distribution by age, gender, smoking, and BMI resulted similar. Group C had significantly higher levels of VEGF, CD34, and CD44 expression compared to the other groups. VEGF, CD34, CD44, and peri-implant pocket depth were all positively correlated. Our study revealed that peri-implantitis is a condition characterized by unique and distinctive features. Our results supported that PPD has a great impact on the peri-implantitis and it is closely related to the inflammation marker expression. The identification of specific biomarkers might help in choosing distinct treatment approaches for target individuals.

Poor Vitamin Status is Associated with Skeletal Muscle Loss and Mucositis in Head and Neck Cancer Patients.

Mucositis and muscle wasting are two common toxicity effects of cancer treatment in head and neck cancer (HNC). There is limited data evaluating cancer treatment toxicities in relation to vitamin status. This study aimed to assess changes in vitamin status during HNC treatment in relation to body composition, inflammation and mucositis. In this prospective cohort study, dietary intakes (3-day food record), plasma levels of vitamins and C-reactive protein (CRP) were assessed at baseline (at diagnosis) and post-treatment (after 6⁻8 weeks of radiation therapy with or without chemotherapy). Computed tomography images were used to quantify body composition. Mucositis information was collected from health records of patients. Twenty-eight HNC patients (age 60 ± 10 years) completed both study time points. Patients who developed mucositis had significantly lower dietary intake of vitamins and plasma 25-hydroxy vitamin D (25-OHD) and all-trans retinol levels (p < 0.02). Patients lost a considerable amount of muscle mass (3.4 kg) and fat mass (3.6 kg) over the course of treatment. There was a trend toward greater muscle loss in patients with 25-OHD < 50 nmol/L compared to patients with 25-OHD ≥ 50 nmol/L (p = 0.07). A significant negative correlation was found between plasma all-trans retinol and CRP level at the end of treatment (p = 0.03). Poor vitamin status could be a contributing factor in developing treatment-induced toxicities.

Use of Intravenous Posaconazole in Hematopoietic Stem Cell Transplant Patients.

BACKGROUND: Posaconazole is a broad-spectrum antifungal used for prophylaxis and treatment of invasive fungal infections. There is no published data to inform prescribers on dosing of the intravenous (IV) formulation in the pediatric population. We describe our experience including dosing, serum concentrations, and tolerability. OBSERVATIONS: Four patients (3 to 9 y) received IV posaconazole for treatment of documented/suspected invasive fungal infections. Patients achieved therapeutic concentrations on daily doses of 8.4 to 12.2 mg/kg and adverse effects were minimal. CONCLUSIONS: Higher dosing per body weight of IV posaconazole may be required in the pediatric population compared with adults to consistently achieve therapeutic concentrations.

Nutritional Status of Hematological Patients before Hematopoietic Stem Cell Transplantation and in Early Posttransplantation Period.

Hematopoietic stem cell transplantation (HSCT) is an aggressive method of treatment affecting patient's homeostasis. The aim of the study was to evaluate the initial nutritional status of HSCT patients and nutritional status in early posttransplantation period. The prospective study included 100 consecutive patients with hematological malignancies subjected to HSCT. The nutritional status evaluation was made using the nutritional screening scales, anthropometric and biochemical parameters, as well. On the day +7 following HSCT significant decrease in concentration of total protein (5.8 g/dl), albumin (3.6 g/dl) and transferrin (165 mg/dl) were observed (P < 0.001), although the mean body mass/BMI were within the normal range. On the day +14, the biochemical parameters of the nutritional status were even lower (P < 0.001). Poorer nutritional status was associated with worse performance status and mucositis escalation. The adequate nutritional support plan is important element of the whole transplantation procedure.

Chemotherapeutic treatment reduces circulating levels of surfactant protein-D in children with acute lymphoblastic leukemia.

BACKGROUND: Surfactant protein D (SP-D) is a host defense molecule of the innate immune system that enhances pathogen clearance and modulates inflammatory responses. We hypothesized that circulating SP-D levels are associated with chemotherapy-induced mucositis and infectious morbidity in children with acute lymphoblastic leukemia (ALL). PROCEDURE: In a prospective study, 43 children receiving treatment for ALL were monitored for mucosal toxicity from diagnosis through the induction phase of treatment. Serial blood draws were taken to determine the levels of SP-D, interleukin-6 (IL-6), C-reactive protein, and white blood cells. Data on fever, antibiotics, and bacteremia were collected. Baseline levels of circulating SP-D were compared with healthy controls. RESULTS: Baseline values of circulating SP-D were similar to levels in healthy controls (median: 829 ng/ml vs. 657 ng/ml, respectively, P > 0.05). After initiation of chemotherapy, a significant reduction in SP-D levels was observed at all time points: 704 ng/ml at day 8, 413 ng/ml at day 15, 395 ng/ml at day 22, and 520 ng/ml at day 29 (all, P < 0.05). No significant associations between SP-D values, the occurrence of mucosal toxicity, or infectious morbidity were observed. However, loss of circulating SP-D from days 8 to 15 was associated with more systemic inflammation, and lower SP-D values at day 15 were associated with elevated intestinal mucositis scores (P < 0.05). CONCLUSIONS: The current study supports the hypothesis that the detrimental effect of chemotherapy on patients' immune functions includes decreased circulating levels of innate mucosal molecules such as SP-D, potentially aggravating mucosal and systemic inflammatory responses.

Absorption of Bupivacaine after Administration of a Lozenge as Topical Treatment for Pain from Oral Mucositis.

The aim was to investigate systemic exposure after administration of a novel bupivacaine lozenge in healthy individuals with normal mucosa and in head and neck cancer (HNC) patients with oral mucositis. A lozenge containing 5, 10, 25 and 50 mg bupivacaine, respectively, was administered as single dose to 10 healthy individuals, and a lozenge containing 25 mg bupivacaine was administered as single dose to 10 HNC patients with oral mucositis and as multiple doses to five patients with HNC. Blood samples were collected for 6 hr from the healthy individuals and 3 hr from the patients with HNC, respectively, after administration. The plasma concentration-time profiles of bupivacaine were fitted to pharmacokinetic models using nonlinear mixed-effects modelling, evaluating demographics and health status as covariates. The population pharmacokinetics (PK) of bupivacaine lozenge was best described by a two-compartment distribution model with absorption transit compartments. All the observed plasma concentrations were well below the bupivacaine concentrations (2000-2250 ng/ml) which have caused toxic symptoms. The PK model suggested that relative bioavailability was two times higher in HNC patients with oral mucositis grade 1-2 and three times higher in HNC patients with oral mucositis grade 3-4 than in the healthy individuals. Simulations showed that the plasma concentrations would be below the toxic limit after repeated dosing every second hour with 25 mg bupivacaine for five days. The 25-mg bupivacaine lozenges were safe without systemic toxic levels of bupivacaine or risk of side effects. Based on PK simulations of repeated doses of 25 mg every two hours for 16 hr a day, the lozenges can be administered with minimum risk of exceeding the toxic limit.

Carvacrol reduces irinotecan-induced intestinal mucositis through inhibition of inflammation and oxidative damage via TRPA1 receptor activation.

Intestinal mucositis is an inflammatory process occurring in the intestinal mucosa and is a common side effect of irinotecan hydrochloride (CPT-11) based anticancer regimens. The transient receptor potential cation channel, subfamily A, member 1 (TRPA1) receptor is highly expressed in the intestinal mucosa and has the ability to identify cell damage signaling indicates its possible association with intestinal mucositis. Carvacrol is an agonist of the TRPA1 receptor and has anti-inflammatory properties. Thus, the aim of the present study was to verify the supposed anti-inflammatory and protective action of carvacrol via TRPA1 activation against intestinal mucositis induced by CPT-11 in mice. Briefly, mice were treated with either DMSO 2% or CPT-11 (75 mg/kg, per 4 days, i.p.) or the carvacrol (25, 75 or 150 mg/kg, per 8 days, i.p.) before CPT-11. In other group, the animals were pretreated with HC-030031, a TRPA1 antagonist, 30 min before treatment with carvacrol. On day 7, animal survival and bacteremia were assessed, and following euthanasia, samples of the jejunum were obtained for morphometric analysis and measurement of antioxidant and pro-inflammatory markers. Carvacrol was found to exert an anti-inflammatory action against CPT-11-induced intestinal mucositis through strong interactions with TRPA1 receptors; reduction in the production or release or both of pro-inflammatory cytokines (TNF-α, IL-1ß, and KC); and decrease in other indicators of inflammation (MPO, NF-κB, COX-2) and oxidative stress (GSH, MDA, and NOx levels). It also contributed to the restoration of the tissue architecture of the villi and crypts in the small intestine, and improved clinical parameters such as survival, body mass variation, leukogram, and blood bacterial count. Thus, TRPA1 could be a target for future therapeutic approaches in the treatment of intestinal mucositis.

Noninvasive Testing for Mucosal Inflammation in Inflammatory Bowel Disease.

Biomarkers have gained increasing attention for the diagnosis and follow-up of inflammatory bowel disease (IBD). Endoscopy remains the gold standard for assessing disease activity. Biomarkers are rapid, inexpensive, and noninvasive, and can be used in different stages of the disease with high sensitivity and specificity. Calprotectin and tests for C-reactive protein are used to assess the disease activity, predict relapse, and monitor treatment response. New noninvasive tests are being studied. This review discusses current evidence for these surrogate markers, their potential clinical applications, and limitations in disease management. We highlight recent advances in IBD biomarkers and future uses.

Mexican Childhood Acute Lymphoblastic Leukemia: A Pilot Study of the MDR1 and MTHFR Gene Polymorphisms and Their Associations with Clinical Outcomes.

BACKGROUND: Genetic polymorphisms in patients with acute lymphoblastic leukemia (ALL) may influence the toxicity of chemotherapeutic agents. Due to the importance of the transport P-glycoprotein and methylenetetrahydrofolate reductase in the metabolism of chemotherapeutic agents, we analyzed the MDR1 rs1045642 and MTHFR rs1801133 polymorphisms and their associations with clinical outcomes in Mexican childhood ALL patients. METHODS: A total of 109 patients participated in this study. The clinical evaluation consisted of a physical examination and a laboratory test. Genotyping of MDR1 rs1045642 (3435 C>T) and MTHFR rs1801133 (677 C>T) was performed by polymerase chain reaction/restriction fragment length polymorphism. Statistical analyses were performed using SPSS 14.0. The odds ratios and 95% confidence intervals (CI) were estimated by logistic regression. RESULTS: Individuals who were CC homozygotes at MDR1 rs1045642 had lower risk of having methotrexate plasma concentrations >1 µM and leukopenia grade I (odds ratio [OR] = 0.30; 95% CI = 0.13-0.72 and OR = 0.32; 95% CI = 0.14-0.72, respectively). Patients who were CC homozygotes at MTHFR rs1801133 had a higher risk of developing mucositis (OR = 3.61; 95% CI = 1.42-9.14). CONCLUSION: MDR1 rs1045642 and MTHFR rs1801133 should be considered as diagnostic candidates for the identification of pediatric patients with a high risk of suffering adverse events during ALL treatment.

Protective effect and potential mechanisms of Wei-Chang-An pill on high-dose 5-fluorouracil-induced intestinal mucositis in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Wei-Chang-An pill (WCA pill), a traditional Chinese pharmaceutical preparation, possessed potential anti-inflammatory advantages and noteworthy gastrointestinal regulations in digestive diseases, which might represent a promising candidate for the treatment of intestinal mucositis (IM) induced by 5-fluorouracil (5-FU). AIM OF THE STUDY: To analyze the bioactive constituents and investigate the effect of methanol extraction from WCA pill (WCA ext) on 5-FU induced IM with underlying mechanisms. MATERIALS AND METHODS: The analysis of serum bioactive constituents after WCA ext administration in rats was carried out by UHPLC-Quadrupole-Time of Flight-Mass Spectrometry. In mice, IM was induced by 5-FU and physical manifestations were measured during the period of drug delivery. Half of mice were assessed with histology, expression of inflammatory cytokines in ileum and plasma via hematoxylin and eosin staining, immunohistochemical staining as well as cytokine enzyme-linked immunosorbent assay test, respectively. Besides, gastric emptying (GE) and gastrointestinal transit (GIT) were further tested in the other half of 5-FU induced mice. RESULTS: Twenty-two compounds were identified or tentatively characterized. IM induced by 5-FU was improved significantly after treatment with WCA ext through reducing the body weight loss, relieving the severe diarrhea, and inhibiting the GE as well as GIT. Further assessments validated that WCA ext promoted the recovery of intestinal mucosa, evaluated the activity of enterocyte proliferation, maintained the integrity of tight junction, and ameliorated the inflammatory disturbances. CONCLUSIONS: These results suggested that WCA ext promoted the restoration of intestinal function in 5-FU-induced IM via regulating multiple sites of actions in intestinal homeostasis. Accordingly, WCA pill might be a promising therapeutic candidate for the prevention of IM during cancer chemotherapy.

Posaconazole plasma exposure correlated to intestinal mucositis in allogeneic stem cell transplant patients.

PURPOSE: Low posaconazole plasma concentrations (PPCs) are frequently encountered in allogeneic hematopoietic stem cell transplant (HSCT) patients, due to variable gastrointestinal absorption. In this study, the impact of intestinal mucositis on posaconazole exposure is investigated. PATIENTS AND METHODS: A prospective pharmacokinetic study was performed including allogeneic HSCT patients receiving posaconazole prophylaxis with the oral suspension or tablets. Steady state PPCs were determined using high-performance liquid chromatography-fluorescence detection at the day of transplantation (=day 0), day +7, and +14. Citrulline was measured using liquid chromatography-tandem mass spectrometry to evaluate severity of mucositis, at baseline (day -7 or -6), and at day 0, +7 and +14. Additionally, citrulline plasma concentrations and steady state trough PPCs were determined in hematological patients without HSCT or mucositis. RESULTS: Thirty-four HSCT patients received posaconazole oral suspension together with 25 cL of Coca Cola, 6 HSCT patients received posaconazole tablets and 33 hematological patients not receiving HSCT received posaconazole oral suspension. The median (interquartile range) average PPC was 0.26 mg/L (0.17-0.43), 0.67 mg/L (0.27-1.38), and 1.08 mg/L (0.96-1.38), with suspension in HSCT patients, suspension in hematological patients and tablets in HSCT patients, respectively. A higher trough PPC was encountered with the oral suspension when citrulline plasma concentrations were above 10 µmol/L compared to values below 10 µmol/L (p < 0.001), whereas for tablets, average PPCs remained high with citrulline plasma concentrations below or above 10 µmol/L (p = 0.64). CONCLUSION: Posaconazole tablets should be preferred to suspension in HSCT patients immediately after transplantation to prevent insufficient plasma exposure due to intestinal mucositis.

Chemotherapy-Induced Intestinal Mucosal Barrier Damage: a Cause of Falsely Elevated Serum 1,3-Beta-d-Glucan Levels?

Blood citrulline and intestinal fatty acid binding protein were determined as biomarkers for intestinal mucositis. Biomarker levels were correlated with corresponding serum 1,3-beta-D-glucan levels in 56 samples obtained from 33 cases with underlying hematological malignancies receiving induction chemotherapy. No correlation between biomarkers of intestinal mucositis and BDG levels was observed. (This study has been registered at ClinicalTrials.gov under registration no. NCT01576653.).

Amelioration of Chemotherapy-Induced Intestinal Mucositis by Orally Administered Probiotics in a Mouse Model.

BACKGROUND AND AIMS: Intestinal mucositis is a frequently encountered side effect in oncology patients undergoing chemotherapy. No well-established or up to date therapeutic strategies are available. To study a novel way to alleviate mucositis, we investigate the effects and safety of probiotic supplementation in ameliorating 5-FU-induced intestinal mucositis in a mouse model. METHODS: Seventy-two mice were injected saline or 5-Fluorouracil (5-FU) intraperitoneally daily. Mice were either orally administrated daily saline, probiotic suspension of Lactobacillus casei variety rhamnosus (Lcr35) or Lactobacillus acidophilus and Bifidobacterium bifidum (LaBi). Diarrhea score, pro-inflammatory cytokines serum levels, intestinal villus height and crypt depth and total RNA from tissue were assessed. Samples of blood, liver and spleen tissues were assessed for translocation. RESULTS: Marked diarrhea developed in the 5-FU groups but was attenuated after oral Lcr35 and LaBi administrations. Diarrhea scores decreased significantly from 2.64 to 1.45 and 0.80, respectively (P<0.001). Those mice in 5-FU groups had significantly higher proinflammatory cytokine levels (TNF-α: 234.80 vs. 29.10, P<0.001, IL-6: 25.13 vs. 7.43, P<0.001, IFN-γ: 22.07 vs. 17.06, P = 0.137). A repairing of damage in jejunal villi was observed following probiotics administration. We also found TNF-α, IL-1ß and IL-6 mRNA expressions were up-regulated in intestinal mucositis tissues following 5-FU treatment (TNF-α: 4.35 vs. 1.18, IL-1ß: 2.29 vs. 1.07, IL-6: 1.49 vs. 1.02) and that probiotics treatment suppressed this up-regulation (P<0.05). No bacterial translocation was found in this study. CONCLUSIONS: In conclusion, our results show that oral administration of probiotics Lcr35 and LaBi can ameliorate chemotherapy-induced intestinal mucositis in a mouse model. This suggests probiotics may serve as an alternative therapeutic strategy for the prevention or management of chemotherapy-induced mucositis in the future.

Substantial decreases in the number and diversity of microbiota during chemotherapy-induced gastrointestinal mucositis in a rat model.

PURPOSE: Earlier, we showed in acute myeloid leukemia (AML) patients that the microbiota changes dramatically during anticancer treatment, coinciding with gastrointestinal mucositis: The commensal anaerobic populations reduce in favor of potential pathogens. Therefore, interventions targeting the microbiota during mucositis might be interesting but can better be tested in animals than in vulnerable mucositis patients. Here, we aimed to study the potential microbial changes during methotrexate (MTX)-induced gastrointestinal mucositis in a well-established rat model and to study whether this model can be used for future microbial intervention studies. METHODS: After injection with MTX or saline (day 0), rats were sacrificed between days 2 and 11. Plasma citrulline level, jejunal histology, and the number and diversity of intestinal bacteria in feces (using fluorescence in situ hybridization (FISH)) were determined. RESULTS: Mucositis was most severe on day 4 when food intake, plasma citrulline, and villus length were the lowest, compared with controls (P < 0.0125). At the same time, MTX-treated rats showed an overall decrease (705-fold) in most bacteria (using a universal probe), compared with controls (P < 0.125). Reduced bacterial presence was related with the presence of diarrhea and a reduced villus length (rho = 0.38, P < 0.05). At day 4, there was an absolute and relative decrease of anaerobes (13-fold and -58 %, respectively) and streptococci (296-fold and -1 %, respectively) but a relative increase of Bacteroides (+49 %), compared with controls (P < 0.125). CONCLUSIONS: In the mucositis rat model, we found substantial decreases in the number and diversity of microbiota, resembling earlier findings in humans. The model therefore seems well suited to study the effects of different microbial interventions on mucositis, prior to performing human studies.

Plasma citrulline level as a biomarker for cancer therapy-induced small bowel mucosal damage.

Regimen-related mucosal toxicity is extremely common following cytotoxic chemotherapy and radiotherapy. Mucositis is as an important determinant of the inflammatory response and infectious complications in cancer treated patients. Most assessment scales for mucosal damage are focussed on oral mucositis, since it is easy to evaluate. Measuring gastrointestinal musocal damage objectively remains difficult because it cannot be seen directly or readily detected. One of potential non-invasive biomarkers of gastrointestinal mucosal damage is plasma citrulline level. Citrulline is an amino acid produced by small bowel enterocytes. Low concentration of free circulating citrulline signifies severe intestinal mucosal damage in humans with nonmalignant disorders, such as villous atrophy-associated diseases, short bowel syndrome, Crohn's disease, and is used in follow-up after small bowel transplantation. The plasma citrulline level is a reliable and objective biochemical marker of enterocyte mass and function in humans, and therefore can be used to monitor enterocyte toxicity resulting from chemotherapy and radiotherapy during anticancer therapy in patients with severely disturbed gut integrity.

Serum citrulline as a biomarker of gastrointestinal function during hematopoietic cell transplantation in children.

OBJECTIVES: We sought to determine whether serum citrulline (CIT), an amino acid produced by small bowel enterocytes, was associated with clinical and biochemical markers of gastrointestinal function in children undergoing hematopoietic cell transplantation (HCT). METHODS: We conducted a multicenter, prospective cohort study of 26 children to define time-related changes in serum CIT during the course of HCT. Markers of gastrointestinal function including oral energy intake, emesis, stool volume, presence of graft-versus-host disease (GVHD), oral mucositis severity, and cytokine and neurohormone levels were measured. Weekly serum CIT concentrations were obtained from 10 days prior until 30 days after HCT. RESULTS: Mean baseline CIT concentration was 22.7 µmol/L (95% confidence interval [CI] 17.7-27.6) on day -10, which decreased to a nadir of 7.5 µmol/L (95% CI 3.1-18.0, P = 0.017) on day 8 following HCT before returning to baseline by day 30. After adjustment for IL-6 level (1.0% lower CIT per 10% increase in interleukin-6, P = 0.004), presence of acute GVHD (27% lower CIT, P = 0.025), and oral energy intake (2.1% lower CIT per 10% decrease in energy intake, P = 0.018), the nadir shifted to day 10, when mean CIT concentration was lower in patients with severe oral mucositis (6.7 µmol/L, 95% CI 3.4-13.1) than in those without severe mucositis (11.9 µmol/L, 95% CI 5.8-24.4, P = 0.003). Change in CIT was not correlated with stool volume, C-reactive protein, tumor necrosis factor-α, leptin, or ghrelin. CONCLUSIONS: In children undergoing HCT, serum CIT correlates with measures of gastrointestinal function (oral mucositis severity, dietary intake, acute GVHD) and may reflect mucosal injury to the gastrointestinal tract.