Salivary Changes before and after Hematopoietic Stem Cell Transplantation: A Systematic Review

Exploring the Influence of Oral and Gut Microbiota on Ulcerative Mucositis: A Pilot Cohort Study

AIM

Comparing oral and gut microbiome profiles between patients with and without ulcerative mucositis during allogeneic stem cell transplantation (aSCT).

MATERIALS AND METHODS

Specimens from oral mucosa, saliva, and stool were collected pre-(T0) and post- (T0 +28d ± 14d) aSCT (T1). Microbiome structure differences were analyzed by 16S-rRNA-gene sequencing, and associations to patients' clinical characteristics were investigated.

RESULTS

Ten of 25 included patients developed ulcerations. The α-diversity decreased between T0 and T1, independent of ulcerations. PERMANOVA revealed differences in beta diversity between T1 stool samples from patients with and without ulcerations. At T1, saliva samples of patients with ulcerations showed an increase of Mycoplasma salvarius, while commensals decreased in saliva and mucosal swabs. The gut microbiome of both groups showed an overabundance of Enterococcus spp., associated with inflammatory conditions. Salival α-diversity of older and overweight patients decreased slower, whereas in mucosal swabs mucositis or impaired renal function was associated with a higher decline. Female gender and history of periodontitis were associated with increased stool microbiome changes, while self-reported probiotics intake was related to reduced changes.

CONCLUSIONS

Ulcerations appeared in 40% of the patients. Distinct microbial changes, including increased abundance of Mycoplasma salivarius in saliva and decreased abundance of commensals, marked those with ulcerations.

TRIAL REGISTRATION

The study was registered in the German Register for Clinical Studies (DRKS00032882).

Enhancing Standardized Practices for Oral Mucositis Prevention in Pediatric Hematopoietic Stem Cell Transplantation: A Best Practice Implementation Project

Background

Oral mucositis (OM) poses a significant challenge in children undergoing hematopoietic stem cell transplantation (HSCT). There is a gap between clinical practice and the evidence, and nursing practices is not standardized.

Objective

This study aims to evaluate the effectiveness of applying the evidence for preventing HSCT chemotherapy-induced OM in children and to elevate the nurses' compliance to the evidence.

Methods

Following the clinical evidence practice application model of the Joanna Briggs Institute (JBI) evidence-Based Care Center. The process included reviewing literature, extracting evidence, identifying gaps, developing audit criteria, conducting a baseline audit, creating an action plan, implementing evidence-based interventions, and assessing outcomes.

Results

After the evidence implementation, 6 out of 12 audit criteria with poor compliance are significantly improved, with statistically significant differences (P<0.05). The incidence of OM decreases, with a statistically significant difference (66.6% vs 36.7%, P=0.02). The incidence of grade I, II, III, and IV OM also decreases (30% vs 23.3%, 23.3% vs 13.4%, 10% vs 0%, and 3.3% vs 0%). Ultimately, the standardized oral care practice routine and workflows to prevent OM were established.

Conclusion

Bridging the gap between evidence and clinical practice can standardize nurse behavior, decrease the incidence of OM, and lower the OM severity in children undergoing HSCT.

Efficacy of Propolis in the Prevention of Oral Mucositis in Patients Undergoing High-Dose Chemotherapy: A Randomized Controlled Trial

BACKGROUND

Oral mucositis is one of the most common symptoms in adults with a hematological cancer who are receiving high-dose chemotherapy. Propolis is a complementary and alternative method used to prevent oral mucositis in these patients.

OBJECTIVE

The aim of this study was to determine the efficacy of propolis in the prevention of oral mucositis in patients receiving high-dose chemotherapy and/or hematopoietic stem cell transplantation.

METHODS

A total of 64 patients, 32 in the propolis group and 32 in the control group, were enrolled in this prospective randomized controlled experimental study. Whereas the standard oral care treatment protocol was administered to the control group, aqueous propolis extract was applied to the propolis intervention group in addition to the standard oral care treatment protocol. Data collection forms included a Descriptive Information Form, the Karnofsky Performance Scale, the Cumulative Illness Rating Scale-Geriatric, Patient Follow-up Form, the World Health Organization Oral Toxicity Scale, and the National Cancer Institute Common Terminology Criteria for Adverse Events.

RESULTS

The incidence and duration of oral mucositis were statistically significantly lower in the propolis intervention group than the control group, and the onset of oral mucositis and grade 2 to 3 oral mucositis occurred later ( P < .05).

CONCLUSION

Propolis mouthwash combined with standard oral care treatment delayed the onset of oral mucositis and decreased its incidence and the number of days it lasted.

IMPLICATIONS FOR PRACTICE

Mouthwash with propolis can be used as a nursing intervention to decrease oral mucositis and its symptoms in hematological cancer patients receiving high-dose chemotherapy.

Assessment of the Salivary Concentrations of Selected Immunological Components in Adult Patients in the Late Period after Allogeneic Hematopoietic Stem Cell Transplantation-A Translational Study

(1) The aim of the study was to analyze the salivary concentrations of lysozyme, lactoferrin, and sIgA antibodies in adult patients in the late period after allogeneic stem cell transplantation (alloHSCT). The relationship between these concentrations and the salivary secretion rate and the time elapsed after alloHSCT was investigated. The relationship between the concentrations of lysozyme, lactoferrin, and sIgA and the titer of the cariogenic bacteria S. mutans and L. acidophilus was assessed. (2) The study included 54 individuals, aged 19 to 67 (SD = 40.06 ± 11.82; Me = 39.5), who were 3 to 96 months after alloHSCT. The concentrations of lysozyme, lactoferrin, and sIgA were assessed in mixed whole resting saliva (WRS) and mixed whole stimulated saliva (WSS). (3) The majority of patients had very low or low concentrations of the studied salivary components (WRS-lysozyme: 52, lactoferrin: 36, sIgA: 49 patients; WSS-lysozyme: 51, lactoferrin: 25, sIgA: 51 patients). The levels of lactoferrin in both WRS and WSS were statistically significantly higher in the alloHSCT group than in the control group (CG) (alloHSCT patients-WRS: M = 40.18 μg/mL; WSS: M = 27.33 μg/mL; CG-WRS: M = 17.58 μg/mL; WSS: 10.69 μg/mL). No statistically significant correlations were observed between lysozyme, lactoferrin, and sIgA concentrations and the time after alloHSCT. In the group of patients after alloHSCT a negative correlation was found between the resting salivary flow rate and the concentration of lactoferrin and sIgA. The stimulated salivary flow rate correlated negatively with lactoferrin and sIgA concentrations. Additionally, the number of S. mutans colonies correlated positively with the concentration of lysozyme and sIgA. (4) The concentrations of non-specific and specific immunological factors in the saliva of patients after alloHSCT may differ when compared to healthy adults; however, the abovementioned differences did not change with the time after transplantation.

Saliva: a challenging human fluid to diagnose brain disorders with a focus on Alzheimer's disease

Biomarkers are molecules of biological processes that help in both the diagnosis of human diseases and in follow-up assessments of therapeutic responses. Biomarkers can be measured in many human fluids, such as blood, cerebrospinal fluid, urine, and saliva. The -omics methods (genomics, RNomics, proteomics, and metabolomics) are useful at measuring thousands of markers in a small volume. Saliva is a human fluid that is easily accessible, without any ethical concerns. Yet, saliva remains unexplored in regard to many human disease biomarkers. In this review, we will give an overview on saliva and how it can be influenced by exogenous factors. As we focus on the potential use of saliva as a diagnostic tool in brain disorders (especially Alzheimer's disease), we will cover how saliva is linked to the brain. We will discuss that saliva is a heterogeneous human fluid, yet useful for the discovery of biomarkers in human disorders. However, a procedure and consensus that is controlled, validated, and standardized for the collection and processing of saliva is required, followed by a highly sensitive diagnostic approach.

Caries, periodontitis and tooth loss after haematopoietic stem cell transplantation: A systematic review

OBJECTIVE

A systematic review was conducted to assess scientific knowledge concerning the effect of haematopoietic stem cell transplantation (HSCT) on the occurrence of caries, periodontal conditions and tooth loss, and to evaluate the prevalence of these diseases in adult HSCT survivors (PROSPERO 152906).

METHODS

PubMed and Embase were searched for papers, published from January 2000 until November 2020 without language restriction, assessing prevalence, incidence or parameters of caries, periodontal conditions and tooth loss in HSCT recipients (≥80% transplanted in adulthood). Bias risk was assessed with checklists from Joanna Briggs Institute, and data synthesis was performed by narrative summary.

RESULTS

Eighteen papers were included (1618 subjects). Half were considered at high risk of bias. Longitudinal studies did not show caries progression, decline in periodontal health or tooth loss after HSCT. The prevalence in HSCT survivors ranged from 19% to 43% for caries, 11% to 67% for periodontitis, and 2% to 5% for edentulism. Certainty in the body of evidence was very low.

CONCLUSIONS

Haematopoietic stem cell transplantation, on the short term, may have little to no effect on caries, periodontal conditions and tooth loss. Caries and periodontitis may be more common in HSCT survivors compared with the general population, whereas edentulism may be comparable. However, the evidence for all conclusions is very uncertain.

Oral microbial changes and oral disease management before and after the treatment of hematological malignancies: a narrative review

OBJECTIVES

Patients with hematological malignancies have dynamic changes in oral microbial communities before and after treatment. This narrative review describes the changes in oral microbial composition and diversity, and discusses an oral microbe-oriented strategy for oral disease management.

MATERIALS AND METHODS

A literature search was performed in PubMed/Medline, Web of Science, and Embase for articles published between 1980 and 2022. Any articles on the changes in oral microbial communities in patients with hematological malignancies and their effects on disease progression and prognosis were included.

RESULTS

Oral sample detection and oral microbial sequencing analysis of patients with hematological malignancies showed a correlation between changes in oral microbial composition and diversity and disease progression and prognosis. The possible pathogenic mechanism of oral microbial disorders is the impairment of mucosal barrier function and microbial translocation. Probiotic strategies, antibiotic strategies, and professional oral care strategies targeting the oral microbiota can effectively reduce the risk of oral complications and the grade of severity in patients with hematological malignancies.

CLINICAL RELEVANCE

This review provides dentists and hematologists with a comprehensive understanding of the host-microbe associated with hematologic malignancies and oral disease management advice.

The effect of hematopoietic stem cell transplantation on patient-reported subjective oral dryness: a systematic review focusing on prevalence, severity and distress

OBJECTIVE

The aim of the present systematic review is to assess the prevalence and severity of and distress caused by xerostomia over time in adult hematopoietic stem cell transplantation (HSCT) recipients.

METHODS

PubMed, Embase, and the Cochrane Library were searched for papers published between January 2000 and May 2022. Clinical studies were included if patient-reported subjective oral dryness was reported in adult autologous or allogeneic HSCT recipients. Risk of bias was assessed according to a quality grading strategy published by the oral care study group of the MASCC/ISOO, resulting in a score between 0 (highest risk of bias) and 10 (lowest risk of bias). Separate analysis focused on autologous HSCT recipients, allogeneic HSCT recipients receiving a myeloablative conditioning (MAC), and those receiving a reduced intensity conditioning (RIC).

RESULTS

Searches yielded 1792 unique records; 22 studies met the inclusion criteria. The quality scores ranged between 1 and 7, with a median score of 4. The prevalence, severity, and distress of xerostomia increased shortly after HSCT. Severity of xerostomia in allogeneic MAC recipients was higher compared to allogeneic RIC recipients 2-5 months post-HSCT (mean difference: 18 points on 0-100 scale, 95% CI: 9-27); after 1-2 years, there was no significant difference anymore.

CONCLUSION

The prevalence of xerostomia in HSCT recipients is high in comparison to the general population. The severity of complaints is raised during the first year post-HSCT. The intensity of the conditioning plays a key role in the short-term development of xerostomia, while factors affecting the recovery in the long term remain largely unknown.

The salivary proteome in relation to oral mucositis in autologous hematopoietic stem cell transplantation recipients: a labelled and label-free proteomics approach

BACKGROUND

Oral mucositis is a frequently seen complication in the first weeks after hematopoietic stem cell transplantation recipients which can severely affects patients quality of life. In this study, a labelled and label-free proteomics approach were used to identify differences between the salivary proteomes of autologous hematopoietic stem cell transplantation (ASCT) recipients developing ulcerative oral mucositis (ULC-OM; WHO score ≥ 2) or not (NON-OM).

METHODS

In the TMT-labelled analysis we pooled saliva samples from 5 ULC-OM patients at each of 5 timepoints: baseline, 1, 2, 3 weeks and 3 months after ASCT and compared these with pooled samples from 5 NON-OM patients. For the label-free analysis we analyzed saliva samples from 9 ULC-OM and 10 NON-OM patients at 6 different timepoints (including 12 months after ASCT) with Data-Independent Acquisition (DIA). As spectral library, all samples were grouped (ULC-OM vs NON-OM) and analyzed with Data Dependent Analysis (DDA). PCA plots and a volcano plot were generated in RStudio and differently regulated proteins were analyzed using GO analysis with g:Profiler.

RESULTS

A different clustering of ULC-OM pools was found at baseline, weeks 2 and 3 after ASCT with TMT-labelled analysis. Using label-free analysis, week 1-3 samples clustered distinctly from the other timepoints. Unique and up-regulated proteins in the NON-OM group (DDA analysis) were involved in immune system-related processes, while those proteins in the ULC-OM group were intracellular proteins indicating cell lysis.

CONCLUSIONS

The salivary proteome in ASCT recipients has a tissue protective or tissue-damage signature, that corresponded with the absence or presence of ulcerative oral mucositis, respectively.

TRIAL REGISTRATION

The study is registered in the national trial register (NTR5760; automatically added to the International Clinical Trial Registry Platform).

Dental consensus on HSCT - Part II: dental Care during HSCT

During the state of immune vulnerability in hematopoietic stem cell transplantation (HSCT), the patient has an increased risk of developing a vast number of complications, including severe problems in the oral cavity. These situations require professional oral care to act in the diagnosis and treatment of these conditions, as well as to develop prevention protocols to minimize patient's complications. Oral mucositis, opportunistic infections, bleeding, specific microbiota, taste, and salivary alterations are complications that can occur during HSCT and interfere with various aspects, such as pain control, oral intake, nutrition, bacteremia and sepsis, days of hospitalization and morbidity. Several guidelines have been published to address the role of professional oral care during the HSCT, we describe a consensus regarding these recommendations.

The Role of Dental Practitioners in the Management of Oncology Patients: The Head and Neck Radiation Oncology Patient and the Medical Oncology Patient

This narrative review addresses the role of a dentist in the management of oncology patients, highlighting the oral complications that arise in head and neck radiation oncology patients and medical oncology patients. The prevention and management of these complications are discussed.

Taste and smell disturbances in patients with chronic oral graft vs. host disease: An observational study

Background

A common complication of allogeneic hematopoietic stem cell transplantation (alloHSCT) is chronic oral graft vs. host disease (cGvHD). Oral cGvHD may present as mucosal lesions, salivary gland dysfunction, and trismus. Moreover, taste and smell ability may be affected, but the prevalence, nature and severity of altered taste and smell function, and their impact on quality of life (QoL) are understudied.

Aim

To identify the prevalence, nature, and severity of taste and smell disturbances, their impact on QoL and to assess whether altered taste/smell ability is associated with oral mucosal cGvHD or hyposalivation.

Materials and methods

AlloHSCT recipients at least 100 days post-HSCT and referred for oral cGvHD-related oral complaints were eligible for participation in this cross-sectional study. Manifestations of oral mucosal cGvHD were scored, the (un)stimulated salivary flow was measured, and objective taste and smell ability was evaluated. Subjective taste and smell alterations, and overall and oral health (OH)-related QoL were assessed.

Results

In total, 45 patients were included, of which objective reduced taste ability (hypogeusia) was identified in 68.9%; 28.9% had reduced smell ability and 11.1% had complete loss of smell. Nevertheless, only 31.1% of patients reported severe taste alterations and 22% reported moderate taste alterations indicating that not all the patients were aware of their altered taste sense. Taste/smell disturbances were not related to oral mucosal cGvHD or hyposalivation. Most alloHSCT recipients reported a decreased OH-related QoL. However, a relation between taste/smell ability and global or OH-related QoL could not be identified.

Conclusion

Taste and smell disturbances are prevalent among alloHSCT recipients. Most patients reported a decreased OH-related QoL, but the specific impact of taste and smell disturbances remains to be elucidated.

Prevalence and Risk Factors for Hyposalivation and Xerostomia in Childhood Cancer Survivors Following Different Treatment Modalities-A Dutch Childhood Cancer Survivor Study Late Effects 2 Clinical Study (DCCSS LATER 2)

Background: Limited data are available on the risk factors of salivary gland dysfunction in long-term childhood cancer survivors (CCS). The objective of this cross-sectional study, part of the multidisciplinary multicenter Dutch CCS Study Late Effects 2 (DCCSS LATER 2), was to assess the prevalence of and risk factors for hyposalivation and xerostomia in CCS. Methods: From February 2016 until March 2020, 292 CCS were included. Data with regard to gender, age at study, diagnosis, age at diagnosis, and treatment characteristics were collected, as well as the unstimulated (UWS) and stimulated whole salivary flow rate (SWS). Xerostomia was assessed with the Xerostomia Inventory (XI) questionnaire. Multivariable Poisson regression analyses were used to evaluate the association between potential risk factors and the occurrence of hyposalivation. Results: The minimum time between diagnosis and study enrollment was 15 years. The prevalence of hyposalivation was 32% and the prevalence of xerostomia was 9.4%. Hyposalivation and xerostomia were not significantly correlated. Risk factors for hyposalivation were female gender and a higher dose of radiotherapy (>12 Gy) to the salivary gland region. Conclusion: Considering the importance of saliva for oral health, screening for hyposalivation in CCS is suggested in order to provide optimal oral supportive care aimed to improve oral health.

Lactoferrin of oral fluid is normal and in Alzheimer's disease: laboratory and diagnostic aspects (review of literature)

The article discusses the clinical value of determining the lactoferrin protein in oral fluid - one of the representatives of the saliva proteome. The review is based on the analysis of modern literature, including systematic reviews, the results of multicenter prospective studies, review and original articles by leading experts in this field, presented in the databases PubMed, Scopus, CyberLeninka. The problems of the preanalytical stage, methods for determining lactoferrin are highlighted and information about its content in mixed saliva according to various authors is provided. Special attention is paid to the clinical and diagnostic value of the level of salivary lactoferrin in Alzheimer's disease. According to most authors, the diagnostic sensitivity of this parameter ranges from 87 to 100%. Some mechanisms of the relationship between this protein and the central nervous system (CNS) are shown. In conclusion, it is concluded that salivary lactoferrin can be an "indicator" of the formation of amyloid plaques and can be considered as one of the reliable biomarkers of Alzheimer's disease. This opinion is based both on fundamental ideas about the global relationship between innate immunity and the central nervous system, and on clinical data. The special advantage of this laboratory test is its non-invasiveness, which makes it more preferable in comparison with the determination of amyloid and tau proteins in the cerebrospinal fluid and blood.

Relevant proteins for the monitoring of engraftment phases after allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Hematopoietic Stem Cell Transplant (HSCT) has been successfully used as standard therapy for hematological disorders. After conditioning therapy, patients undergoing allogeneic HSCT, present three different phases of engraftment: early pre-engraftment, early post-engraftment, and late engraftment. Severe complications are associated with morbidity, mortality, and malignancies in these phases, which include effects on the oral cavity.

OBJECTIVES

The changes in the salivary composition after HSCT may contribute to identifying relevant proteins that could map differences among the phases of diseases, driven for personalized diagnostics and therapy.

METHODS

Unstimulated whole saliva was collected from patients submitted to HSCT. The samples were submitted to trypsin digestion for a Mass spectrometry analysis. MaxQuant processed the Data analysis, and the relevant expressed proteins were subjected to pathway and network analyses.

RESULTS

Differences were observed in the most identified proteins, specifically in proteins involved with the regulation of body fluid levels and the mucosal immune response. The heatmap showed a list of proteins exclusively expressed during the different phases of HSCT: HBB, KNG1, HSPA, FGB, APOA1, PFN1, PRTN3, TMSB4X, YWHAZ, CAP1, ACTN1, CLU and ALDOA. Bioinformatics analysis implicated pathways involved in protein processing in the endoplasmic reticulum, complement and coagulation cascades, apoptosis signaling, and cholesterol metabolism.

CONCLUSION

The compositional changes in saliva reflected the three phases of HSCT and demonstrated the usefulness of proteomics and computational approaches as a revolutionary field in diagnostic methods.

Is Salivary Busulfan the Cause of Oral Mucositis and the Changes in Salivary Antioxidant Enzymes After Hematopoietic Cell Transplantation?

BACKGROUND

To determine whether the busulfan (Bu) present in saliva during hematopoietic cell transplantation (HCT) conditioning correlates with oral mucositis and the changes in salivary antioxidant enzymes.

METHODS

Bu levels in the plasma and saliva of 19 patients who received HCTs were quantified. Salivary flow and salivary superoxide dismutase and catalase activities were measured during HCT. For the toxicity analysis of salivary Bu, an in vitro assay was conducted by exposing human keratinocytes to artificial saliva containing Bu.

RESULTS

Plasma and salivary Bu concentrations were very similar (rho = 0.92, P < 0.001). Salivary Bu concentration correlated with the degree of oral mucositis severity (rho = 0.391, P = 0.029) and was inversely proportional to salivary superoxide dismutase and catalase activities (rho = -0.458, P = 0.036; rho = -0.424, P = 0.043, respectively). Cells exposed to Bu-containing saliva had fewer viable cells (P < 0.01) and more apoptotic cells (P = 0.001) than those exposed to non-Bu-containing saliva.

CONCLUSIONS

Bu found in saliva during HCT conditioning was correlated with severe oral mucositis and the reduction in salivary antioxidative activity. Furthermore, Bu can be toxic to keratinocytes.

Salivary BPIFA proteins are altered in patients undergoing hematopoietic cell transplantation

OBJECTIVE

The aim of this study was to evaluate the expression of BPIFA proteins in the saliva and salivary glands of hematopoietic cell transplant (HCT) patients.

MATERIAL AND METHODS

This longitudinal study included patients who had undergone autologous HCT (auto-HCT) and allogeneic HCT (allo-HCT), and unstimulated saliva was collected at three time points, with a fourth collection at oral chronic graft-versus-host disease (cGVHD) onset. BPIFA expression was analysed by Western blotting in saliva and immunostaining in the minor salivary glands of cGVHD patients.

RESULTS

Auto-HCT patients showed increased levels of BPIFA1 (p = .021) and BPIFA2 at D+7 (p = .040), whereas allo-HCT group demonstrated decreased expression of BPIFA2 at D+8 (p = .002) and at D+80 (p = .001) and a significant association between BPIFA2 low levels and hyposalivation was observed (p = .02). BPIFA2 was significantly lower in the cGVHD patients when compared to baseline (p = .04).

CONCLUSIONS

The results of this study show distinct pattern of expression of BPIF proteins in both auto-HCT and allo-HCT recipients with decreased levels of BPIFA2 during hyposalivation and cGVHD. Further studies are necessary to elucidate these proteins mechanisms and their clinical implications in these groups of patients.

Salivary antioxidant enzymes associated with oral toxicity in haematopoietic cell transplantation: An observational study

BACKGROUND

In haematopoietic cell transplantation (HCT), oral mucositis and xerostomia are related to conditioning-related oxidative stress. The role of salivary antioxidant enzymes in oral toxicity is poorly described. The aim of this study was to verify the association between salivary antioxidant enzymes and oral mucositis and xerostomia in HCT.

DESIGN

Saliva from autologous and allogeneic HCT patients (n = 77) was selected before conditioning (T0), during the neutropenia period (T1) and after marrow engraftment (T2). Salivary flow, total salivary proteins, and superoxide dismutase, catalase and glutathione reductase activities were measured.

RESULTS

There were no significant differences in salivary flow, total salivary proteins and catalase at the three HCT time points. Glutathione reductase levels were reduced at T1 compared to T0 (P = .013) and T2 (P = .001). Superoxide dismutase levels were increased from T0 to T2 (P = .013). Neither of these enzymes was associated with oral mucositis. Increased superoxide dismutase levels were associated with xerostomia frequency. Levels of this enzyme also showed significant correlation with days of xerostomia in T2 (ρ = .40, P = .002).

CONCLUSIONS

Salivary antioxidant enzymes changed before and during early periods after HCT. The increase in salivary superoxide dismutase suggested partial activation of the salivary antioxidant system and was associated with xerostomia.

Significant salivary changes in relation to oral mucositis following autologous hematopoietic stem cell transplantation

The aim of this multicentre, longitudinal study was to determine salivary changes in relation to oral mucositis (OM) in multiple myeloma patients following high-dose melphalan and autologous hematopoietic stem cell transplantation (ASCT). Unstimulated and stimulated whole-mouth saliva samples (UWS and SWS) were collected before ASCT, 1×/wk during the hospitalisation phase, and 3 and 12 months post-ASCT. During the hospitalisation period OM was scored 3×/wk (WHO system). Flow rate, pH, total protein concentration (Nanodrop), albumin, lactoferrin, neutrophil defensin-1 (HNP1), total IgA and S100A8/A9 (ELISA) were determined. Mixed models were used to evaluate differences between ulcerative (u)OM (≥2 WHO, n = 20) and non-uOM (n = 31) groups. Until 18 days after ASCT, flow rate, pH, total IgA and HNP1 levels decreased in UWS and/or SWS, while log lactoferrin levels were significantly increased (UWS: p = 0.016 95% CI [0.36, 3.58], SWS: p < 0.001 95% CI [1.14, 3.29]). Twelve months post-ASCT, salivary protein levels were similar to baseline except for log total IgA, which was higher (UWS: p < 0.001 95% CI [0.49, 1.29], SWS: p < 0.001 95% CI [0.72, 1.45]). No differences between uOM and non-uOM groups were observed. Changes in salivary proteins indicated an inflammatory reaction in salivary glands coinciding with mucosal and systemic reactions in response to high-dose melphalan.

Oral microorganisms and bloodstream infection in allogeneic hematopoietic stem cell transplantation

OBJECTIVES

We aimed to compare oral and pathogenic microorganisms in bloodstream infections (BSIs) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). We also investigated the relationship between BSIs and oral mucositis to identify the ratio of BSIs caused by oral microorganisms and the pathogenic microorganisms involved.

MATERIALS AND METHODS

We collected data on BSIs in 96 patients who underwent allo-HSCT in our institute between April 2009 and December 2019, including BSI pathogens isolated from blood cultures (BBSIs) and microorganisms isolated from washing the oral cavity with sterile distilled water. Oral microorganisms obtained at the onset of BSI (OBSIs) and during allo-HSCT (OSCTs) were defined as isolates collected during the week of blood culturing. Study entry was limited to samples collected up to 1 month after allo-HSCT without BSI. When the BBSI and OBSI were the same, we considered the oral microorganism to have caused the BSI.

RESULTS

The incidence rate of BSIs was 27%, and the predominant microorganism was coagulase-negative Staphylococci. Normal bacterial flora were decreased to 15.8% in OBSIs and 25.5% in OSCTs. The distribution of microorganisms without normal bacterial flora showed significant difference between BBSIs and OSCTs (p < 0.05). Oral mucositis was found in 72.9%, and BSI caused by oral microorganisms occurred in 46.2% of BSIs in allo-HSCT patients.

CONCLUSION

The distribution of microorganisms obtained from blood in patients with BSI during allo-HSCT was found to be similar to that of microorganisms from oral cultures.

CLINICAL RELEVANCE

Oral microorganism monitoring may be able to predict BSI during allo-HSCT.

Effects of Consuming Catha Edulis Forsk (khat)on the Gene Manifestation of CHRM1 and CHRM3 in relation to Salivary Glands, Saliva Flow Rates, pH and Dental Caries in Yemeni Consumers

Background:

The current study has been conducted to estimate the impact of Catha Edulis Forsk (simply known as khat) on pH and saliva flow rate in teeth unaffected by caries among patients from Arab, Yemen, consuming the plant. The goal was to evaluate the relation of these indicators with gene manifestation ofCHRM1andCHRM3,which contributes to the regulation of saliva secretions.

Methods:

Overall, 60 respondents aged between 27 and 54 years were selected for the research. They were distributed among two groups, group I and group II, including 30 respondents equally. Group I incorporated respondents consuming no khat, having teeth caries, adequate saliva flow, and generally, healthy oral cavity. In turn, group II incorporated respondents consuming khat having caries-free teeth, inadequate saliva flow and relatively unhealthy oral cavity. Saliva samples were taken from all respondents. They were analyzed for indicators of flow rate as well as pH of saliva. Salivary gland biopsy specimens have also been taken. The whole RNA was allocated, cDNA synthesized and reinforced to estimate the gene manifestation ofCHRM1andCHRM3.

Results:

A considerable rise in the mean salivary flow rate along with a drastic decline in the mean salivary pH within caries-free teeth among the respondents consuming khat was observed during the study. The mRNA expressionsCHRM1andCHRM3were significantly increased among participants consuming khat. Results were contrasted to the control group of patients not consuming khat.

Conclusion:

The characteristics of salivary flow rate, pH, and caries-free teeth have been related to the gene manifestations ofCHRM1andCHRM3in respondents consuming khat.

The Biology of Lactoferrin, an Iron-Binding Protein That Can Help Defend Against Viruses and Bacteria

Lactoferrin is a nutrient classically found in mammalian milk. It binds iron and is transferred via a variety of receptors into and between cells, serum, bile, and cerebrospinal fluid. It has important immunological properties, and is both antibacterial and antiviral. In particular, there is evidence that it can bind to at least some of the receptors used by coronaviruses and thereby block their entry. Of importance are Heparan Sulfate Proteoglycans (HSPGs) and the host receptor angiotensin-converting enzyme 2 (ACE2), as based on other activities lactoferrin might prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from attaching to the host cells. Lactoferrin (and more specifically enteric-coated LF because of increased bioavailability) may consequently be of preventive and therapeutic value during the present COVID-19 pandemic.