Salivary calprotectin is elevated in patients with active inflammatory bowel disease

Salivary calprotectin and neutrophils in inflammatory bowel disease in relation to oral diseases

OBJECTIVE

Calprotectin is elevated in saliva from inflammatory bowel disease (IBD) patients, but it is also affected by oral disease. We assessed the salivary concentration of calprotectin in IBD patients, in relation to intestinal and oral diseases. Furthermore, we investigated the phenotype of salivary neutrophils from IBD patients, and their ability to secrete calprotectin.

MATERIALS AND METHODS

Thirty IBD patients and 26 controls were orally examined and sampled for stimulated saliva. Twenty-five IBD patients provided fresh fecal samples. Calprotectin concentrations in saliva and feces were determined by an enzyme-linked immunosorbent assay. Expression of CD11b, CD15, and CD16 on oral neutrophils was assessed by flow cytometry. Secretion of calprotectin was evaluated in cultured oral neutrophils.

RESULTS

Calprotectin was significantly elevated in saliva of IBD patients compared to controls, particularly in Crohn's disease, irrespective of caries or periodontitis. Salivary calprotectin did not correlate to fecal calprotectin. CD11b expression was significantly reduced in salivary neutrophils from IBD patients. Salivary neutrophils from IBD patients tended to secrete more calprotectin than controls.

CONCLUSIONS

Salivary calprotectin is elevated in IBD regardless of oral diseases. Furthermore, salivary neutrophils secrete calprotectin, and display lower CD11b expression in IBD.

Changes in S100A8/A9 and S100A12 and Their Comparison with Other Analytes in the Saliva of Pigs with Diarrhea Due to E. coli

The family of calgranulins includes S100A8 (calgranulin A), S100A9 (calgranulin B), which can appear as a heterodimer known as S100A8/A9 or calprotectin, and S100A12 (calgranulin C). These proteins are related to different inflammatory conditions, immune-mediated diseases, and sepsis and are considered biomarkers of potential interest. This study aims to evaluate if S100A8/A9 and A12 could change in pigs with diarrhea due to E. coli and to compare the changes of S100A8/A9 and A12 with other analytes in order to explore the possible causes or mechanisms involved. For this purpose, a panel integrated by analytes related to inflammation (haptoglobin, inter-alpha trypsin inhibitor 4 (ITIH4), and total protein); immune system (adenosine deaminase, ADA); stress (alpha-amylase); tissue damage (lactate and lactate dehydrogenase (LDH)); sepsis (aldolase) and redox status (ferric-reducing ability of saliva (FRAS) and advanced oxidation protein products (AOPP)) was evaluated. S100A8/A9 and A12 and the other analytes measured in this study showed increases in the saliva of pigs with diarrhea due to E. coli. S100A8/A9 and/or A12 showed a significant correlation of different magnitude with some of the other analytes evaluated. Further studies should be conducted to gain knowledge about the possible practical applications as biomarkers of the measurements of S100A8/A9 and A12 in the saliva of pigs.

S-100 Proteins: Basics and Applications as Biomarkers in Animals with Special Focus on Calgranulins (S100A8, A9, and A12)

S100 proteins are a group of calcium-binding proteins which received this name because of their solubility in a 100% saturated solution of ammonium sulphate. They have a similar molecular mass of 10-12 KDa and share 25-65% similarity in their amino acid sequence. They are expressed in many tissues, and to date 25 different types of S100 proteins have been identified. This review aims to provide updated information about S100 proteins and their use as biomarkers in veterinary science, with special emphasis on the family of calgranulins that includes S100A8 (calgranulin A; myeloid-related protein 8, MRP8), S100A9 (calgranulin B; MRP14), and S100A12 (calgranulin C). The proteins SA100A8 and S100A9 can be linked, forming a heterodimer which is known as calprotectin. Calgranulins are related to the activation of inflammation and the immune system and increase in gastrointestinal diseases, inflammation and sepsis, immunomediated diseases, and obesity and endocrine disorders in different animal species. This review reflects the current knowledge about calgranulins in veterinary science, which should increase in the future to clarify their role in different diseases and potential as biomarkers and therapeutic targets, as well as the practical use of their measurement in non-invasive samples such as saliva or feces.

Measurement of Calprotectin (S100A8/A9) in the Saliva of Pigs: Validation Data of A Commercially Available Automated Assay and Changes in Sepsis, Inflammation, and Stress

Calprotectin (CALP, S100A8/A9), also named myeloid-related protein 8/14, is a dimer complex of S100A8 and S100A9 that belongs to the S-100 protein family. It is involved in inflammation and has a wide range of proinflammatory functions, such as cytokine production and regulation of leukocyte adhesion, migration, and phagocytosis. In humans, CALP traditionally can be measured in faeces, serum, and saliva as a biomarker of inflammation and sepsis. The objective of this study was to validate an automated assay for CALP measurements in the saliva of pigs, having the advantage of the use of a non-invasive sample that is easy to collect. The assay was precise and accurate. CALP in saliva measured by this assay showed significant changes depending on the hour of the day. It also showed significant increases in the saliva of pigs after the administration of lipopolysaccharide (LPS), and showed a rise, although with increases of lower magnitude, after a stressful stimulus. Further studies should be made to gain knowledge about the possible practical applications of the measurements of CALP in the saliva of pigs as a biomarker to evaluate the animals’ health and welfare.

Gum-gut axis: The potential role of salivary biomarkers in the diagnosis and monitoring progress of inflammatory bowel diseases

The gut mucosa is an extension of the oral mucosa, and both are directly linked. There is emerging evidence that pathogenic oral microbiome contributes greatly to the risk of developing Inflammatory Bowel Disease (IBD). Dysbiosis of the oral microbiota can interfere with the host immune system's ability to respond normally, thereby increasing the development of periodontitis which raises the risk of IBD, cancer, rheumatoid arthritis, cardiovascular disease, and other complex disease processes. Salivary biomarkers are possibly important for determining the incidence, severity, and remission of IBD. Nevertheless, clinical translation of biomarker knowledge from lab to clinical practice needs further studies that identify biomarkers related to the transitional phase between healthy and unhealthy. In this review, the bidirectional pathway between the gut and the oral cavity was investigated and several aspects were discussed.

Pathogenic associations between oral and gastrointestinal diseases

Both periodontitis and inflammatory bowel disease (IBD) are complex chronic conditions characterized by aberrant host immune response and dysregulated microbiota. Emerging data show an association between periodontitis and IBD, including direct and indirect mechanistic links between oral and intestinal inflammation. Direct pathways include translocation of proinflammatory microbes from the oral cavity to the gut and immune priming. Indirect pathways involve systemic immune activation with possible nonspecific effects on the gut. There are limited data on the effects of periodontal disease treatment on IBD course and vice versa, but early reports suggest that treatment of periodontitis decreases systemic immune activation and that treatment of IBD is associated with periodontitis healing, underscoring the importance of recognizing and treating both conditions.

Oral Cavity Calprotectin and Lactoferrin Levels in Relation to Radiotherapy

Background: Lactoferrin, an iron-binding glycoprotein, and calprotectin, a calcium binding protein, are sensitive markers of inflammation and their fecal levels increase during radiotherapy of prostate cancer patients. With this background, we analyzed mouthrinse calprotectin and lactoferrin levels of head- and neck-cancer patients before, during and after radiotherapy. Methods: Twenty cancer patients (mean age 55.85 ± 15.01, 80% male), who had been planned to undergo radiotherapy to the head and neck area, were included in this study. Mouthrinse samples were collected before radiotherapy, at the 3rd and 6th weeks of radiotherapy and 4 weeks after the radiotherapy. Mouthrinse samples were analyzed for calprotectin and lactoferrin using commercial ELISA kits. Results: Calprotectin levels increased significantly during radiotherapy (p = 0.022). Both markers, lactoferrin (p = 0.011) and calprotectin (p = 0.006), decreased significantly after the treatment. Conclusions: Present study results may suggest that the elevations in calprotectin and lactoferrin levels during radiotherapy reflect the increased and emerging inflammatory environment in the oral cavity, thus may increase the risk of periodontal disease initiation or progression.

Inflammatory markers in saliva and urine reflect disease activity in patients with systemic lupus erythematosus

BACKGROUND

Laboratory tests of blood and sometimes urine are used to diagnose and to monitor disease activity (DA) in SLE. Clinical practice would be simplified if non-invasive urine and salivary tests could be introduced as alternatives to blood samples. We therefore explored the levels of innate immunity-related biomarkers in matched serum, urine and saliva samples from patients with SLE.

METHODS

A total of 84 patients with SLE selected to represent high and low general DA, and 21 controls were included. All participants underwent a thorough clinical examination. General DA and renal DA were measured. The levels of colony-stimulating factor (CSF)-1, interleukin (IL)-34, tumour necrosis factor (TNF)-α, interferon-γ-induced protein (IP)-10, monocyte chemoattractant protein (MCP)-1, calprotectin, macrophage inflammatory protein (MIP)-1α and MIP-1β were analysed by immunoassays and related to DA.

RESULTS

CSF-1, TNF-α, IP-10 and MCP-1 in saliva, serum and urine, as well as calprotectin in saliva and urine were increased in patients with SLE as compared with controls (p<0.05). TNF-α, IP-10 and MCP-1 in saliva, serum and urine, and CSF-1 in saliva and serum distinguished patients with SLE from controls (area under the curve >0.659; p<0.05 for all). CSF-1 in serum and urine, and calprotectin in saliva and urine, as well as TNF- α, IP-10 and MCP-1 in urine correlated positively with measures of general DA (p<0.05). Patients with SLE with active renal disease presented elevated levels of TNF-α, IP-10 and MCP-1 in urine and CSF-1 and IP-10 in serum as compared with patients with SLE with non-active renal disease.

CONCLUSIONS

Our investigation demonstrates that saliva is a novel alternative body fluid, with potential for surveillance of general DA in patients with SLE, but urine is more informative in patients with SLE with predominantly renal DA.

Changes in Salivary Parameters of Oral Immunity after Biologic Therapy for Inflammatory Bowel Disease

We previously observed that inflammatory bowel disease (IBD) may compromise oral host defense, as assessed by decreased salivary levels of immunoglobulin A (IgA) and myeloperoxidase (MPO). Biologic therapy with inhibitors of cytokines or adhesion molecules is increasingly used for patients with IBD. Little is known, however, about how this treatment modality affects the release and properties of saliva. Here, we aimed to determine how biologic therapy in patients who had not responded to previous standard treatment with conventional drugs affected the salivary concentration of IgA and MPO. To this end, unstimulated whole mixed saliva was collected before treatment or after 10-12 weeks of therapy from 27 patients with Crohn's disease (CD) and 24 patients with ulcerative colitis (UC). After the induction phase of therapy with biologics, salivary levels of IgA and MPO increased significantly in UC, but not in CD patients. These increases were approximately 8-fold and 6-fold, for IgA and MPO, respectively. Moreover, these effects occurred in UC patients who responded successfully to therapy, but not in those who failed to improve. Furthermore, the relative increases in salivary IgA and MPO correlated with the relative decrease in UC severity, as assessed by the Mayo scale. These data indicate that the successful therapy with biologics in UC patients results also in improved oral host defense. However, it remains to be determined why such an effect does not occur during therapy for CD.

Calprotectin (S100A8/A9) Is an Innate Immune Effector in Experimental Periodontitis

Upregulated in inflammation, calprotectin (complexed S100A8 and S100A9; S100A8/A9) functions as an innate immune effector molecule, promoting inflammation, and also as an antimicrobial protein. We hypothesized that antimicrobial S100A8/A9 would mitigate change to the local microbial community and promote resistance to experimental periodontitis in vivo. To test this hypothesis, S100A9-/- and wild-type (WT; S100A9+/+) C57BL/6 mice were compared using a model of ligature-induced periodontitis. On day 2, WT mice showed fewer infiltrating innate immune cells than S100A9-/- mice; by day 5, the immune cell numbers were similar. At 5 days post ligature placement, oral microbial communities sampled with swabs differed significantly in beta diversity between the mouse genotypes. Ligatures recovered from molar teeth of S100A9-/- and WT mice contained significantly dissimilar microbial genera from each other and the overall oral communities from swabs. Concomitantly, the S100A9-/- mice had significantly greater alveolar bone loss than WT mice around molar teeth in ligated sites. When the oral microflora was ablated by antibiotic pretreatment, differences disappeared between WT and S100A9-/- mice in their immune cell infiltrates and alveolar bone loss. Calprotectin, therefore, suppresses emergence of a dysbiotic, proinflammatory oral microbial community, which reduces innate immune effector activity, including early recruitment of innate immune cells, mitigating subsequent alveolar bone loss and protecting against experimental periodontitis.

Potential Salivary Markers for Differential Diagnosis of Crohn's Disease and Ulcerative Colitis

The properties of the saliva of patients with inflammatory bowel disease (IBD) are poorly recognized. Likewise, the diagnostic potential of saliva for differentiating various forms of IBD is largely unexplored. Therefore, we compared the concentrations of several parameters in unstimulated whole mixed saliva collected in a standardized manner from patients with active IBD unresponsive to conventional therapy. The samples were received from 27 patients with Crohn’s disease (CD), 24 patients with ulcerative colitis (UC), and 51 healthy individuals. Compared to the controls, the salivary concentrations of S100A8/calprotectin, myeloperoxidase, and IgA were significantly decreased in both CD and UC patients. In addition, patients with UC had decreased levels of TNF-R1 and decreased catalase activity. Interestingly, the concentrations of myeloperoxidase and TNF-R1 showed a high differentiation potential for CD and UC (AUC = 0.690 and 0.672, respectively). All these findings are discussed in the context of host defense in the oral cavity, patients’ prior treatment regimens, and smoking habits.

Parent Perspectives of Diagnostic and Monitoring Tests Undertaken by Their Child with Inflammatory Bowel Disease

PURPOSE

To assess parent perspectives of the current and potential future tests for their child with inflammatory bowel disease (IBD).

METHODS

New Zealand parents of a child with IBD were invited to complete an anonymous online survey. Experiences relating to their child's blood or faecal tests, medical imaging (abdominal ultrasound [US], abdominal computerised tomography [CT] and magnetic resonance enterography) and colonoscopy were collected. Perceived attitudes to potential future testing of urine, saliva, and breath, were sought.

RESULTS

Twenty-eight parents, 93% female completed the survey, and 86% were aged between 35 and 54 years. Baseline information was provided by parents for 27 of 28 children, 70.3% had Crohn's disease with a mean disease duration of 2.67 years. Blood tests were the most requested and completed tests, while CT was the least ordered and most refused test. Colonoscopy was rated as the least comfortable and generated the most worry. Explanation of test significantly improved parent's levels of understanding when their child had blood, faecal, imaging (US) or colonoscopy tests. Providing an explanation, test invasiveness and the impact of the blood results may have on their child's treatment significantly improved parents' comfort levels. However, explanation of colonoscopy generated a significant parental concerns. Saliva, urine and blood tests were chosen as the most preferred disease monitoring tests.

CONCLUSION

Parents preferred any tests less invasive than colonoscopy for monitoring their child's IBD. Although providing explanation of their child's tests enhanced parents' understanding, it can also affect parents' levels of concern and comfort.

Fecal calprotectin in healthy children aged 4-16 years

Reference values of fecal calprotectin (fCP) have not been convincingly established in children. We aimed to investigate fCP concentrations in a larger population of healthy children aged 4–16 years to analyze more in depth the behavior of fCP in this age range and to determine if cut-off levels could be conclusively recommended. A prospective study was conducted to investigate fCP concentrations of healthy children aged 4–16 years. In 212 healthy children, the median and 95th percentile for fCP were 18.8 mg/kg and 104.5 mg/kg, respectively. We found a statistically significant association between the 95th percentile of fCP concentrations and age (p < 0.001). We propose a nomogram to facilitate the interpretation of fCP results in children aged 4–16 years. Further studies are required to validate the proposed values in clinical practice.

Salivary Stress/Immunological Markers in Crohn's Disease and Ulcerative Colitis

There is continuous and growing interest in research into new alternatives to standard biomarkers to detect and follow-up disease, reducing physical and psychological stress in patients needing regular and invasive medical examinations for the evaluation of pathologies, including inflammatory bowel diseases (IBD). Saliva is one of the most promising body fluids in the research of new biomarkers, thanks to the large number of molecules it contains. Many molecules present in saliva are often directly correlated to their concentration in the blood but may be affected by the condition of the oral cavity. This means that a careful selection of a specific biomarker is required for each pathology, especially pathologies such as IBD, which may induce inflammation in the oral cavity. Here, we analyze the currently used and the proposed new salivary biomarkers (i.e., calprotectin, cytokines, IgA, cortisol, and oxidative stress markers) for the detection and follow-up of the main subtypes of IBD, known as ulcerative colitis and Crohn's disease.

Peri-implant treatment reduces the salivary levels of Colony stimulator factor-1 and S100A8/A9

This study evaluated the impact of peri-implant treatment in the salivary levels of Colony stimulator factor -1 (CSF-1), S100A8/A9 and S100A12 in patients having mucositis or peri-implantitis. As a secondary aim, we analysed the correlation between the salivary and peri-implant crevicular fluid (PICF) levels. Forty-seven patient, 27 having mucositis (mean age 63.11 ± 7.78) and 20 having peri-implantitis (61.25 ± 7.01) participated in the study. Clinical parameters, probing pocket depth, clinical attachment level, % of plaque and bleeding on probing were evaluated. Unstimulated whole saliva was collected from all patients, while PICF was collected only from a patient's subgroup (n = 20). Samples were collected before and 3 months after peri-implant treatment. Enzyme-linked immunosorbent assays determined levels of CSF-1, S100A8/A9 and S100A12. Clinical parameters improved and salivary levels of CSF-1 and S100A8/A9, but not S100A12, reduced significantly after treatment in both groups. No significant correlation was found in the salivary and PICF levels of the same molecule. In conclusion, the treatment of peri-implant disease significantly improved the clinical parameters and reduced the salivary levels of CSF-1 and S100A8/A9. The salivary expressions of CSF-1, S100A8/A9 and S100A12 did not correlate with their own expression in PICF.

Calprotectin in inflammatory bowel disease

The term IBD is usually used for referring to a group of inflammatory gastro-intestinal diseases (mainly Crohn's disease and ulcerative colitis). Accordingly, IBD arises as a result of inappropriate immune response to intestinal commensal organisms among genetically susceptible individuals. Performing colonoscopy and histopathologic evaluation on an inflamed bowel biopsy specimen are currently considered as gold standards for diagnosis and management of IBD. Correspondingly, these techniques are known to be invasive and costly. In recent decades, fecal calprotectin, as a biomarker, has received much attention for the diagnosis and non-invasive management of IBD. Up to now, many studies have investigated the efficacy of fecal calprotectin in the areas of IBD differentiation from IBS, prediction of endoscopic and histologic activities of IBD and prediction of disease recurrence. Although some of these studies have reported promising results, some others have shown significant limitations. Therefore, in this paper, we reviewed the most interesting ones of these studies after a brief discussion of the laboratory measurement of fecal calprotectin. Moreover, we attempted to provide an answer for the question of whether fecal-calprotectin could be considered as a potential surrogate marker for colonoscopy.

Salivary Biomarkers for Diagnosis of Inflammatory Bowel Diseases: A Systematic Review

Saliva as a biological fluid has a remarkable potential in the non-invasive diagnostics of several systemic disorders. Inflammatory bowel diseases are chronic inflammatory disorders of the gastrointestinal tract. This systematic review was designed to answer the question “Are salivary biomarkers reliable for the diagnosis of inflammatory bowel diseases?”. Following the inclusion and exclusion criteria, eleven studies were included (according to PRISMA statement guidelines). Due to their heterogeneity, the potential salivary markers for IBD were divided into four groups: oxidative status markers, inflammatory cytokines, microRNAs and other biomarkers. Active CD patients manifest decreased activity of antioxidants (e.g., glutathione, catalase) and increased lipid peroxidation. Therefore, malondialdehyde seems to be a good diagnostic marker of CD. Moreover, elevated concentrations of proinflammatory cytokines (such as interleukin 1β, interleukin 6 or tumour necrosis factor α) are associated with the activity of IBD. Additionaly, selected miRNAs are altered in saliva (overexpressed miR-101 in CD; overexpressed miR-21, miR-31, miR-142-3p and underexpressed miR-142-5p in UC). Among other salivary biomarkers, exosomal PSMA7, α-amylase and calprotectin are detected. In conclusion, saliva contains several biomarkers which can be used credibly for the early diagnosis and regular monitoring of IBD. However, further investigations are necessary to validate these findings, as well as to identify new reliable salivary biomarkers.

Salivary and Serum Inflammatory Profiles Reflect Different Aspects of Inflammatory Bowel Disease Activity

BACKGROUND

Inflammatory bowel disease (IBD) can manifest both macroscopically and microscopically in the oral cavity; however, little is known about salivary changes in IBD. Therefore, this study aimed to assess salivary and circulatory inflammatory profiles in IBD and to compare their potential to reflect the presence and activity of IBD.

METHODS

We measured 92 known inflammatory proteins in serum and in unstimulated and stimulated whole saliva samples from patients with IBD with active intestinal inflammation (n = 21) and matched control patients (n = 22) by proximity extension assay. Fifteen of the patients with IBD returned 10 to 12 weeks after treatment escalation for resampling.

RESULTS

Sixty-seven of the proteins were detected in all 3 sample fluids but formed distinct clusters in serum and saliva. Twenty-one inflammatory proteins were significantly increased and 4 were significantly decreased in the serum of patients with IBD compared with that of the control patients. Two of the increased serum proteins, IL-6 and MMP-10, were also significantly increased in stimulated saliva of patients with IBD and correlated positively to their expressions in serum. None of the investigated proteins in serum or saliva were significantly altered by IBD treatment at follow-up. Overall, inflammatory proteins in serum correlated to biochemical status, and salivary proteins correlated positively to clinical parameters reflecting disease activity.

CONCLUSIONS

Saliva and serum inflammatory profiles in IBD share a similar composition but reflect different aspects of disease activity. The oral cavity reflects IBD through elevated IL-6 and MMP-10 in stimulated saliva.