Serum concentrations of orosomucoid: improved decision-making for tapering prednisolone therapy in patients with active inflammatory bowel disease?

Molecular alterations in oral cancer between tobacco chewers and smokers using serum proteomics

BACKGROUND

Tobacco exposure (through smoking or chewing) is one of the predominant risk factors associated with the development of oral squamous cell carcinoma (OSCC). Despite the growing number of patients diagnosed with OSCC, there are few circulating biomarkers for identifying individuals at a higher risk of developing the disease. Successful identification of candidate molecular markers for risk assessment could aid in the early detection of oral lesions and potentially be used for community screening of high-risk populations.

OBJECTIVE

Identification of differentially expressed proteins in the serum of oral cancer patients which can serve as biomarkers for the diagnosis of the onset of oral cancer among tobacco users.

METHODS

We employed a tandem mass tag (TMT)-based quantitative proteomics approach to study alterations in the serum proteomes of OSCC patients based on their tobacco exposure habits (chewing and smoking) compared to healthy individuals with no history of using any form of tobacco or any symptoms of the disease.

RESULTS

Mass spectrometry-based analysis resulted in the identification of distinct signatures in the serum of OSCC patients who either chewed or smoked tobacco. Pathway analysis revealed opposing effects of dysregulated proteins enriched in the complement-coagulation signaling cascades with a high expression of the Serpin family of proteins observed in OSCC patients who chewed tobacco compared to healthy individuals whereas these proteins showed decreased levels in OSCC patients who smoked. ELISA-based validation further confirmed our findings revealing higher expression of SERPINA6 and SERPINF1 across serum of OSCC patients who chewed tobacco compared to healthy individuals.

CONCLUSIONS

This study serves as a benchmark for the identification of serum-based protein markers that may aid in the identification of high-risk patients who either chew tobacco or smoke tobacco.

Quantitative proteomic analysis exploring progression of colorectal cancer: Modulation of the serpin family

Colorectal cancer (CRC) remains a major cause of cancer related-death in developed countries. The mortality risk is correlated with the stage of CRC determined at the primary diagnosis and early diagnosis is associated with enhanced survival rate. Currently, only faecal occult blood tests are used to screen for CRC. Consequently, there is an incentive to identify specific markers of CRC. We used quantitative proteomic analysis of serum samples to characterize protein profiles in adenoma, CRC and healthy control samples. We identified 89 distinct proteins modulated between normal, colorectal adenoma and carcinoma patients. This list emphasizes proteins involved in enzyme regulator activities and in particular the serpin family. In serum samples, protein profiles of three members of the serpin family (SERPINA1, SERPINA3 and SERPINC1) were confirmed by ELISA assays. We obtained sensitivity/specificity values of 95%/95% for both SERPINA1 and SERPINC1, and 95%/55% for SERPINA3. This study supports the idea that serum proteins can discriminate adenoma and CRC patients from unaffected patients and reveals a panel of regulated proteins that might be useful for selecting patients for colonoscopy. By evaluating SERPINA1, SERPINA3 and SERPINC1, we highlight the potential role of the serpin family during the development and progression of CRC.

SIGNIFICANCE

Colorectal cancer (CRC) remains a major cause of cancer mortality throughout the world. However, very few CRC biomarkers have satisfactory sensitivity and specificity in clinical practice. To the best of our knowledge our study is the first to profile sera proteomes between adenoma, CRC and healthy patients. We report a comprehensive list of proteins that may be used as early diagnostic biomarkers of CRC. It is noteworthy that 17% of these modulated proteins have been previously described as candidate biomarkers in CRC. Enzyme regulator activity was found to be the main molecular function among these proteins and, in particular, there was an enrichment of members of the serpin family. The subsequent verification on a new cohort by ELISA demonstrates that these serpins could be useful to discriminate healthy from colorectal carcinoma patients with a high sensitivity and specificity. The combination of these biomarkers should increase predictive powers of CRC diagnosis. The remaining candidates form a reserve for further evaluation of additional biomarkers for CRC diagnosis.

Correlation between serological biomarkers and endoscopic activity in patients with inflammatory bowel disease

BACKGROUND/AIMS

Endoscopy is the gold standard for assessing disease severity in inflammatory bowel disease (IBD), although it is an invasive procedure. Biological markers have been routinely used as a non-invasive means of determining disease activity. The aim of this study was to determine the correlation between common biological markers and endoscopic activity in IBD.

METHODS

Consecutive patients with IBD were included. Serum concentrations of different biomarkers (C-reactive protein [CRP], orosomucoid [ORM], erythrocyte sedimentation rate [ESR], fibrinogen, platelets, leukocytes, neutrophils and hemoglobin [Hb]) were measured, and their accuracy in detecting endoscopic activity was determined.

RESULTS

Eighty patients were included (mean age 46 years, 53% Crohn's disease), 70% with endoscopic activity. Among Crohn's disease patients, 24% had mild endoscopic activity, 12% moderate activity and 39% severe activity. Among ulcerative colitis patients, 35% had an endoscopic Mayo score of 0-1 points, 30% 2 points and 35% 3 points. None of the biomarkers included had a good correlation with endoscopic activity (Area Under the ROC curve [AUC]<0.70) in ulcerative colitis. ORM, fibrinogen and platelets had the best accuracy to detect endoscopic activity in Crohn's disease (AUC: 0.80-0.085). A sub-analysis in postoperative Crohn's disease patients found no correlation between endoscopic recurrence and biomarkers (AUC<0.70).

CONCLUSION

Serological biomarkers, including CRP, have low accuracy to detect endoscopic activity in ulcerative colitis and postoperative Crohn's disease. ORM, fibrinogen and platelets have the best accuracy to detect endoscopic activity in Crohn's disease.

Clinical Utility of Biomarkers in IBD

There is no gold standard for the diagnosis and monitoring of inflammatory bowel diseases (IBD). Biomarkers are useful tools for the management of patients suffering from IBD. However, they should be used only when their additional information is useful for clinical decision-making. In principal, four situations during the management of an individual IBD patient can be discriminated from a clinical standpoint in which biomarkers provide useful information. First, biomarkers may be helpful when the diagnosis of IBD is established and aid in the discrimination between ulcerative colitis (UC) and Crohn's disease (CD) is necessary. Second, biomarkers may be helpful in the prognostic evaluation of IBD severity or disease behavior and for early decisions on the best treatment. The third situation in which biomarkers are useful is the evaluation of disease activity during the disease course, for monitoring and for guidance of ongoing treatment. Finally, the fourth typical situation when biomarkers are of value is after surgery to predict or diagnose a relapse of the disease. From a clinical point of view, it may be more useful to discuss specific biomarkers and their individual value and impact in these four prototypic situations than to sum up advantages and disadvantages for each biomarker isolated from the clinical situation. Therefore, this overview is structured in chapters reflecting those four typical situations during the disease course of IBD patents to critically evaluate the potential and value of each of the biomarkers in the specific situation.

The potential role of ORM2 in the development of colorectal cancer

Colorectal cancer (CRC) is the third most common malignancy in the world. The risk of death is closely correlated to the stage of CRC at the time of primary diagnosis. Therefore, there is a compelling need for the identification of blood biomarkers that can enable early detection of CRC. We used a quantitative proteomic approach with isobaric labeling (iTRAQ) to examine changes in the plasma proteome of 10 patients with CRC compared to healthy volunteers. Enzyme-Linked Immunosorbnent Assay (ELISA) and Western blot were used for further validation. In our quantitative proteomics analysis, we detected 75 human plasma proteins with more than 95% confidence using iTRAQ labeling in conjunction with microQ-TOF MS. 9 up-regulated and 4 down-regulated proteins were observed in the CRC group. The ORM2 level in plasma was confirmed to be significantly elevated in patients suffering from CRC compared with the controls. ORM2 expression in CRC tissues was significantly increased compared with that in corresponding adjacent normal mucous tissues (P<0.001). ITRAQ together with Q-TOF/MS is a sensitive and reproducible technique of quantitative proteomics. Alteration in expression of ORM2 suggests that ORM2 could be used as a potential biomarker in the diagnosis of CRC.

Prediction of flare-ups of ulcerative colitis using quantitative immunochemical fecal occult blood test

AIM: To examine the feasibility of predicting the flare-up of ulcerative colitis (UC) before symptoms emerge using the immunochemical fecal occult blood test (I-FOBT).

METHODS: We prospectively measured fecal hemoglobin concentrations in 78 UC patients using the I-FOBT every 1 or 2 mo.

RESULTS: During a 20 mo-period, 823 fecal samples from 78 patients were submitted. The median concentration of fecal hemoglobin was 41 ng/mL (range: 0-392 500 ng/mL). There were three types of patients with regard to the correlation between I-FOBT and patient symptoms; the synchronous transition type with symptoms (44 patients), the unrelated type with symptoms (19 patients), and the flare-up predictive type (15 patients). In patients with the flare-up predictive type, the values of I-FOBT were generally low during the study period with stable symptoms. Two to four weeks before the flare-up of symptoms, the I-FOBT values were high. Thus, in these patients, I-FOBT could predict the flare-up before symptoms emerged.

CONCLUSION: Flare-up could be predicted by I-FOBT in approximately 20% of UC patients. These results warrant periodical I-FOBT in UC patients.

Selective white cell apheresis reduces relapse rates in patients with IBD at significant risk of clinical relapse

BACKGROUND

We assessed whether selective granulocyte and monocyte/macrophage adsorption apheresis maintained clinical remission in asymptomatic inflammatory bowel disease (IBD) patients at significant risk of clinical relapse.

METHODS

Sixty asymptomatic patients (age 18-70 years) with IBD (in clinical remission) with fecal calprotectin over 250 microg/g (which defines those at risk of clinical relapse with >80% specificity and sensitivity) were recruited for this open-label, prospective, randomized, controlled study. Twenty-nine underwent selective leukocytapheresis, undergoing 5, once weekly, out-patient sessions. Thirty-one had unchanged maintenance treatment and acted as controls. Follow-up for a clinical relapse was 6 months. The secondary outcome variable was the time to relapse.

RESULTS

The number of patients who remained in clinical remission at 6 months was significantly lower in controls (32.3%) than in the apheresis (72.4%) group (P = 0.0023, Fisher's exact test). The time to first relapse was significantly earlier in the control group (99 +/- 73 days) as compared with the apheresis group (161 +/- 44 days) (log-rank test; P = 0.0004). Mild and transient headache was reported by 16 of the 29 (55%) for up to 3 hours, but no serious side effects were observed.

CONCLUSIONS

This study represents a new approach to the treatment of IBD by targeting a group of asymptomatic patients for treatment who are at significant risk of relapse based on high fecal calprotectin concentrations. Selective leukocytapheresis significantly reduced the number of, and increased the time to, clinical relapse in these patients without serious side effects.

How accurate are clinical activity indices for scoring of disease activity in inflammatory bowel disease (IBD)?

Clinical activity indices are essential instruments in monitoring inflammatory bowel diseases such as Crohn's disease (CD) and ulcerative colitis (UC). To subclassify components of disease indices in CD and UC, investigate technical noise in estimation of the indices, establish a signal-to-noise ratio (SNR), evaluate correlation between indices and calculate the reference change value (RCV) for selected biochemical variables in individual cases, 50 patients with CD and 49 patients with UC were included in the study. Qualitative index variables were assessed for scoring errors. The standard deviation (SD) was estimated according to a rectangular model, while SD in biochemical variable scoring was estimated according to a Gaussian model; a combined SD was also calculated. These values were investigated for their individual contribution to variation. The 95% CI of an index value was based on +/- 1.96 x SD(combined) and a change in separate biochemical variables was calculated as RCV 1.96 x radical2 x SD(combined). Correlation between different disease activity indices was assessed for unexplained variation. The Crohn's disease activity index (CDAI) had the highest variation compared to the van Hees (Hees) and the Harvey-Bradshaw index (HBI) in CD, but it also had the best SNR, whereas HBI had the lowest. In UC the clinical activity index (CAI) showed the highest variance, but the best SNR compared to Seo's activity index (AI). The 95% CI of the CDAI discriminatory activity sum of 150 in individual cases was 105-195, whereas the 95% interval for a change was +/-62.4. Self-reported wellness contributed 40% to total variance in the CDAI. Factors of clinical importance increased errors in estimates and variance of the indices. Poor correlation was obtained between activity indices, with up to 70% unexplained variance. The SD(combined) for estimated errors was as high as 23 points, with the best SNR being approximately 20. Index factors increase the sensitivity of SNRs to errors and lower the disease specificity. Sensitivity optimisation may be achieved by standardisation of the variables and their use.

Discordant erythrocyte sedimentation rate and C-reactive protein in children with inflammatory bowel disease taking azathioprine or 6-mercaptopurine

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by periods of relapse and remission. Treatment is aimed at reducing symptoms during relapse and prolonging the duration of remissions. 6-Mercaptopurine (6-MP) and its prodrug azathioprine (AZA) are commonly used to prolong clinical remissions. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are two widely used laboratory markers of inflammation. The authors observed an unexplained discordance between ESR and CRP in children with asymptomatic IBD who were being treated with AZA or 6-MP.

OBJECTIVE

To characterize children with IBD in remission treated with 6-MP or AZA who have persistently elevated ESR but normal CRP.

METHODS

All patients seen in Pediatric Gastroenterology Clinic between January 1, 1995, and December 31, 2002, with Crohn disease or ulcerative colitis who received AZA or 6-MP continuously for at least 6 months were identified and their medical records reviewed.

RESULTS

One hundred twenty patients met the eligibility criteria. Twelve had an ESR >18 mm/hour on at least three occasions during at least 12 consecutive months with a simultaneous CRP <0.8 mg/dL. Eleven of these 12 had no signs or symptoms of active disease and had Pediatric Crohn Disease Activity Index scores <10 for at least 12 consecutive months while the ESR was elevated. Disease duration was similar in the 11 children with asymptomatic disease and with discordant ESR and CRP and in 108 children with concordant ESR and CRP (69.2 + 22.5 months v 54.3 +/- 40.1 months, P = 0.0709). Duration of AZA or 6-MP therapy was greater in the 11 children with asymptomatic disease and discordant ESR and CRP than in those with or without symptoms and with concordant ESR and CRP (58.1 +/- 16.4 months v 36.6 +/- 24.1 months, P = 0.0043). There were no differences between the groups with respect to diagnosis, location of disease, or age at onset of symptoms. The mean corpuscular volume (MCV) was somewhat larger in the children with discordant ESR and CRP than in the children with concordant ESR and CRP (91.4 +/- 6.97 fL v 87.0 +/-7.07 fL, respectively, P = 0.0373); however, in both groups, the MCV was in the normal range. There were no significant differences in hematocrit, white blood cell count, serum albumin, total serum protein, or estimated serum globulin between the groups.

CONCLUSIONS

The results suggest that among children treated with AZA or 6-MP, CRP may be a more reliable indirect indicator of inflammation than ESR. This report alerts clinicians that some children taking AZA or 6-MP may have persistent elevation of the ESR with a normal CRP and have no clinical evidence of active disease.

Fecal alpha 1-antitrypsin clearance as a marker of clinical relapse in patients with Crohn's disease of the distal ileum

BACKGROUND

Crohn's disease (CD) shows a chronic relapsing course but no marker of relapse is currently available. However, fecal alpha 1-antitrypsin (alpha 1-AT) clearance (alpha 1-ATCl) is an indicator of protein loss and increases during active inflammation. We assessed the usefulness of fecal alpha 1-ATCl in predicting clinical relapse in patients with inactive ileal CD.

DESIGN

In a prospective longitudinal study, 26 patients with inactive ileal CD (Crohn's disease activity index (CDAI) < 150) (18 males, mean age 43 +/- 10, range 23-58) were enrolled. Fecal alpha 1-ATCl and concentration, daily stool weight and serum alpha 1-AT were measured at baseline (visit 1), after 1 week (visit 2) and 3 weeks (visit 3) in 24/26 patients (two drop-outs) (short-term study). In six of these 26 patients, fecal alpha 1-ATCl was also measured every 3 months for 1 year (long-term study). All patients were clinically assessed every 3 months for 1 year and every 6 months for 2 years. Ten healthy volunteers were tested as controls.

METHODS

Serum and fecal alpha 1-AT concentration was quantified by radial immunodiffusion.

RESULTS

The median fecal alpha 1-ATCl value at baseline was higher in inactive patients undergoing clinical relapse (CDAI > 200) in the next 6 months than in those remaining in remission at 6 months (P = 0.03). Fecal alpha 1-ATCl showed a 75% sensitivity, 85% specificity, 50% positive predictive value and 94% negative predictive value in predicting CD relapse in the next 6 months. In the long-term follow-up, fecal alpha 1-ATCl values increased at 12 months compared with both baseline and 6 month values (P = 0.005; P = 0.009). Fecal alpha 1-ATCl was higher in patients with raised C-reactive protein (P = 0.039).

CONCLUSIONS

Results from our study suggest that fecal alpha 1-ATCl is an indicator of clinical relapse in patients with CD of the distal ileum under regular surveillance.

Non-invasive investigation of inflammatory bowel disease

The assessment of inflammatory activity in intestinal disease in man can be done using a variety of different techniques. These range from the use of non-invasive acute phase inflammatory markers measured in plasma such as C reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) (both of which give an indirect assessment of disease activity) to the direct assessment of disease activity by intestinal biopsy performed during endoscopy in association with endoscopic scoring systems. Both radiology and endoscopy are conventional for the diagnosis of inflammatory bowel disease (IBD). However these techniques have severe limitations when it comes to assessing functional components of the disease such as activity and prognosis. Here we briefly review the value of two emerging intestinal function tests. Intestinal permeability, although ideally suited for diagnostic screening for small bowel Crohn’s disease, appears to give reliable predictive data for imminent relapse of small bowel Crohn’s disease and it can be used to assess responses to treatment. More significantly it is now clear that single stool assay of neutrophil specific proteins (calprotectin, lactoferrin) give the same quantitative data on intestinal inflammation as the 4-day faecal excretion of 111Indium labelled white cells. Faecal calprotectin is shown to be increased in over 95% of patients with IBD and correlates with clinical disease activity. It reliably differentiates between patients with IBD and irritable bowel syndrome. More importantly, at a given faecal calprotectin concentration in patients with quiescent IBD, the test has a specificity and sensitivity in excess of 85% in predicting clinical relapse of disease. This suggests that relapse of IBD is closely related to the degree of intestinal inflammation and suggests that targeted treatment at an asymptomatic stage of the disease may be indicated.

Human alpha-1-glycoprotein and its interactions with drugs

For about half a century, the binding of drugs to plasma albumin, the "silent receptor," has been recognized as one of the major determinants of drug action, distribution, and disposition. In the last decade, the binding of drugs, especially but not exclusively basic entities, to another plasma protein, alpha 1-acid glycoprotein (AAG), has increasingly become important in this regard. The present review points out that hundreds of drugs with diverse structures bind to this glycoprotein. Although plasma concentration of AAG is much lower than that of albumin, AAG can become the major drug binding macromolecule in plasma with significant clinical implications. Also, briefly reviewed are the physiological, pathological, and genetic factors that influence binding, the role of AAG in drug-drug interactions, especially the displacement of drugs and endogenous substances from AAG binding sites, and pharmacokinetic and clinical consequences of such interactions. It can be predicted that in the future, rapid automatic methods to measure binding to albumin and/or AAG will routinely be used in drug development and in clinical practice to predict and/or guide therapy.

Lipocalins as biochemical markers of disease

Lipocalins as biochemical markers of disease have been used extensively. The clinical indications relate to almost any field of medicine, such as inflammatory disease, cancer, lipid disorders, liver and kidney function. Some of the more well-known lipocalins that have been used as markers of disease are orosomucoid, Protein HC (alpha(1)-microglobulin), apolipoprotein D, retinol-binding protein, complement C8 gamma, prostaglandin D synthase and human tear prealbumin, and these markers will be briefly reviewed in this article. Emphasis, however, will be put on the description of another newly described lipocalin, i.e. human neutrophil lipocalin/neutrophil gelatinase-associated lipocalin (HNL/NGAL), since the body fluid measurement of HNL/NGAL was shown to be a superior means to distinguish between acute viral and bacterial infections and also to accurately reflect the activity and involvement of neutrophils in a variety of other diseases.

Surrogate markers of intestinal inflammation are predictive of relapse in patients with inflammatory bowel disease

BACKGROUND & AIMS

Prediction of relapse of inflammatory bowel disease has important implications for therapeutic strategies. We assessed whether measurement of intestinal permeability and inflammation could predict relapse of inflammatory bowel disease (IBD).

METHODS

Forty-three patients with Crohn's disease (CD) and 37 with ulcerative colitis (UC) in clinical remission provided a stool sample to be assayed for calprotectin (a neutrophil-specific marker), and patients with CD additionally underwent a small intestinal permeability test. Relapse was defined using clinical disease activity indices.

RESULTS

Twenty-five (58%) patients with CD and 19 (51%) with UC had a relapse over the 12-month period. Median calprotectin levels in the relapse groups (122 mg/L for CD, 123 mg/L for UC; normal <10 mg/L) differed significantly (P<0.0001) from those of the nonrelapse groups (41.5 mg/L for CD, 29.0 mg/L for UC). At 50 mg/L, the sensitivity and specificity of calprotectin for predicting relapse in all patients with IBD were 90% and 83%, respectively. Permeability in the CD patients who relapsed (median, 0.075; normal <0.04) differed significantly (P = 0. 004) from that in the nonrelapse group (median, 0.038). At the level of 0.05, the sensitivity and specificity of permeability in predicting relapse were 84% and 61%, respectively.

CONCLUSIONS

Fecal calprotectin predicts clinical relapse of disease activity in patients with CD and UC, whereas small intestinal permeability is a useful predictor of relapse in patients with small intestinal CD.

Markers of coagulation and fibrinolysis as measures of disease activity in inflammatory bowel disease

BACKGROUND

Activation of coagulation and fibrinolysis occurs in patients with inflammatory bowel disease. Our aim was to study the course of a marker for activation of the coagulation cascade, prothrombin fragment 1 + 2 (F1+2), and fibrinolysis, fibrin degradation products (FbDP), in patients with ulcerative colitis and Crohn's disease before and during therapy with glucocorticoids.

METHODS

Twenty-seven patients with active ulcerative colitis and 42 with active Crohn's disease treated with glucocorticoids were studied. Plasma samples were drawn before, during, and at end of therapy or at time of treatment failure. F1+2 and FbDP were measured with commercially available enzyme immunoassays.

RESULTS

Mean base-line concentrations of F1+2 were significantly increased in patients with ulcerative colitis (4.77 +/- 0.50 nmol/l; P < 0.0001) and in Crohn's disease (4.66 +/- 0.59 nmol/l; P < 0.0001) compared with healthy controls (1.57 +/- 0.09 nmol/l). Mean base-line concentrations of FbDP were significantly increased in patients with ulcerative colitis (1264 +/- 161 microg FE/l; P < 0.0001) and in Crohn's disease (491 +/- 51 microg FE/l; P < 0.0001) compared with healthy controls (194 +/- 21 microg FE/l). During treatment with glucocorticoids the plasma concentrations of FbDP decreased in patients with Crohn's disease achieving remission and in patients with ulcerative colitis avoiding surgery but remained unchanged in patients not responding to therapy. In contrast, F1+2 remained increased in patients with Crohn's disease and ulcerative colitis irrespective of outcome.

CONCLUSION

The present data support the concept that coagulation cascade and fibrinolysis is activated in patients with active inflammatory bowel disease. F1+2 and FbDP correlate poorly with the clinical disease activity and acute-phase reactants. The clinical response to treatment with glucocorticoids is accompanied by a decrease in plasma concentrations of FbDP but not in F1+2. FbDP may emerge as a new marker in the assessment of disease activity in patients with inflammatory bowel disease.