DcR3, TFF3, and Midkine Are Novel Serum Biomarkers in Small Intestinal Neuroendocrine Tumors

Small intestinal neuroendocrine tumors (SI-NETs) are amine- and peptide-producing neoplasms. Most patients display metastases at the time of diagnosis; they have an unpredictable individual disease course and the tumors are often therapy resistant. Chromogranin A and 5-hydroxyindoleacetic acid are the biomarkers clinically used most often today, but there is a great need for novel diagnostic and prognostic biomarkers and new therapeutic targets. Sixty-nine biomarkers were screened in serum from 23 SI-NET patients and 23 healthy controls using the multiplex proximity ligation assay (PLA). A refined method, the proximity extension assay (PEA), was used to analyze 76 additional biomarkers. Statistical testing and multivariate classification were performed. Immunohistochemistry and ELISA were performed in an extended cohort. Using PLA, 19 biomarkers showed a significant difference in serum concentrations between patients and controls, and PEA revealed a difference in the concentrations of 17 proteins. Multivariate classification analysis revealed decoy receptor 3 (DcR3), trefoil factor 3 (TFF3), and midkine to be good biomarkers for the disease, which was confirmed by ELISA analysis. All 3 biomarkers were expressed in tumor tissue. DcR3 concentrations were elevated in patients with stage IV disease. High concentrations of DcR3 and TFF3 were correlated to poor survival. DcR3, TFF3, and midkine exhibited elevated serum concentrations in SI-NET patients compared to healthy controls, and DcR3 and TFF3 were associated with poor survival. DcR3 seems to be a marker for liver metastases, while TFF3 and midkine may be new diagnostic biomarkers for SI-NETs.

Diagnostic value evaluation of trefoil factors family 3 for the early detection of colorectal cancer

AIM

The purpose of this study was to evaluate the diagnostic value of trefoil factor family 3 (TFF3) for the early detection of colorectal cancer (CC).

METHODS

Serum TFF3 and carcino-embryonic antigen (CEA) were detected in 527 individuals, including 115 healthy control (HC), 198 colorectal adenoma (CA), and 214 CC individuals in the training group.

RESULTS

Serum TFF3 showed no significant correlation with age, gender, or tumor location but showed significant correlation with the tumor stage. Serum TFF3 in the CC group was significantly higher than in the HC or CA group. The AUC values of TFF3 for discriminating between HC and CC and between CA and CC were 0.930 (0.903, 0.958) and 0.834 (0.796, 0.873). A multivariate model combining TFF3 and CEA was built. Compared to TFF3 or CEA alone, the multivariate model showed significant improvement (P < 0.001). For discriminating between HC and CC, HC and early stage CC, HC and advanced stage CC, CA and CC, CA and early stage CC, and CA and advanced stage CC in the training group, the sensitivities were 92.99%, 91.46%, 93.18%, 73.83%, 76.83%, and 81.82%, and the specificities were 91.30%, 91.30%, 93.91%, 88.38%, 77.27%, and 88.38%, respectively. After validation, the sensitivities were 89.39%, 85.71%, 90.79%, 72.73%, 71.43%, and 78.95%, and the specificities were 87.85%, 87.85%, 2.52%, 87.85%, 80.77%, and 87.50%, respectively.

CONCLUSION

The multivariate diagnostic model that included TFF3 and CEA showed significant improvement over the conventional biomarker CEA and might provide a potential method for the early detection of CC.

Serum trefoil factor 3 predicts disease activity in patients with ulcerative colitis

OBJECTIVE

In this study, we aimed to evaluate the role of serum trefoil factor 3 (TFF3) as a biomarker of disease activity in patients with inflammatory bowel disease (IBD) and to compare TFF3 values with those of fecal calprotectin (FC).

PATIENTS AND METHODS

128 patients with IBD were divided into four groups: 1) active ulcerative colitis (UC); 2) quiescent UC; 3) active Crohn's disease (CD); 4) quiescent CD. The serum levels of TFF3 and FC levels were assessed in all patients and 16 controls.

RESULTS

Patients with active UC had higher TFF3 levels than those with quiescent UC (p<0.001), those with active (p<0.001) or quiescent CD (p<0.001) and controls (p <0.001). We found a correlation between TFF3 and FC values in patients with active (r = 0.478, p = 0.006) and quiescent UC (r=0.528, p=0.002). TFF3 levels correlated with endoscopic activity in UC (evaluated by UC Endoscopic Index of Severity - UCEIS) (r=0.662, p<0.001).

CONCLUSIONS

Serum TFF3 is able to identify patients with active UC. It could be used as a marker to predict disease activity in patients with UC.

Trefoil Factor 3 is Highly Predictive of Complete Mucosal Healing Independently and in Combination with C-Reactive Protein in Patients with Ulcerative Colitis

AIM

In the current study we aimed to evaluate the role of trefoil factor 3 (TFF3) as a marker for complete mucosal healing (MH) in patients with ulcerative colitis (UC).

METHODS

We enrolled 116 consecutive UC patients. Trefoil factor 3 levels were measured by ELISA and were compared to the clinical activity, assessed by Lichtiger Index, fecal calprotectin (FCP) and C-reactive protein (CRP) levels. Colonoscopy was performed in all the patients and the findings were graded according to Mayo endoscopic score (EMS) and UC endoscopic index of severity (UCEIS).

RESULTS

Trefoil factor 3 levels were significantly correlated with Lichtiger Index (r=0.736, p<0.001), EMS (r=0.811, p<0.001), UCEIS (r=0.820, p<0.001), FCP (r=0.696, p<0.001) and CRP (r=0.405, p<0.001). The TFF3 cut-off level of 6.74 ng/ml indicated complete MH (EMS=0; UCEIS=0) with a sensitivity and specificity of 0.879 and 0.869, respectively (area under the curve, AUC 0.927; 95% confidence interval, 0.877-0.976). The DeLong's test revealed no significant difference between the AUC of TFF3+CRP and the AUC of FCP (Z=1.717, p=0.086), AUC of TFF3+FCP (Z=1.908, p=0.056), and AUC of TFF3+CRP+FCPP (Z=1.915, p=0.056). However, the AUC of TFF3+CRP showed significant difference compared with the AUC of TFF3 (Z=2.210, p=0.027) and the AUC of CRP (Z=3.145, p=0.002) for predicting complete MH.

CONCLUSIONS

Trefoil factor 3 levels correlated significantly with clinical activity, endoscopic indices, CRP and FCP in our patients. TFF3 is a highly predictive marker of complete MH independently and in combination with CRP in patients with UC.

Blood Biomarkers of Intestinal Epithelium Damage Regenerating Islet-derived Protein 3α and Trefoil Factor 3 Are Persistently Elevated in Patients with Alcoholic Hepatitis

BACKGROUND

Heavy alcohol consumption disrupts gut epithelial integrity, leading to increased permeability of the gastrointestinal tract and subsequent translocation of microbes. Regenerating islet-derived protein 3α (REG3α) and Trefoil factor 3 (TFF3) are mainly secreted to the gut lumen by Paneth and Goblet cells, respectively, and are functionally linked to gut barrier integrity. Circulating levels of REG3α and TFF3 have been identified as biomarkers for gut damage in several human diseases. We examined whether plasma levels of REG3α and TFF3 were dysregulated and correlated with conventional markers of microbial translocation (MT) and pro-inflammatory mediators in heavy drinkers with and without alcoholic hepatitis (AH).

METHODS

Cross-sectional and longitudinal studies were performed to monitor plasma levels of REG3α and TFF3 in 79 AH patients, 66 heavy drinkers without liver disease (HDC), and 46 healthy controls (HC) at enrollment and at 6- and 12-month follow-ups. Spearman correlation was used to measure the relationships of REG3α and TFF3 levels with MT, disease severity, inflammation, and effects of abstinence from alcohol.

RESULTS

At enrollment, AH patients had significantly higher levels of REG3α and TFF3 than HDC and HC. The elevated REG3α levels were positively correlated with the 30-day fatality rate. Plasma levels of REG3α and TFF3 in AH patients differentially correlated with conventional MT markers (sCD14, sCD163, and LBP) and several highly up-regulated inflammatory cytokines/chemokines/growth factors. At follow-ups, although REG3α and TFF3 levels were decreased in AH patients with alcohol abstinence, they did not fully return to baseline levels.

CONCLUSIONS

Circulating levels of REG3α and TFF3 were highly elevated in AH patients and differentially correlated with AH disease severity, MT, and inflammation, thereby serving as potential biomarkers of MT and gut epithelial damage in AH patients.

Trefoil factor-3 is not a useful marker of mucosal healing in Crohn's disease treated with anti-TNF-α antibodies

AIM

To evaluate whether repeated serum measurements of trefoil factor-3 (TFF-3) can reliably reflect mucosal healing (MH) in Crohn’s disease (CD) patients treated with anti-tumor necrosis factor-α (anti-TNF-α) antibodies.

METHODS

Serum TFF-3 was measured before and after anti-TNF-α induction therapy in 30 CD patients. The results were related to clinical, biochemical and endoscopic parameters. MH was defined as a ≥ 50% decrease in Simple Endoscopic Score for Crohn’s disease (SES-CD).

RESULTS

SES-CD correlated significantly with CD clinical activity and several standard biochemical parameters (albumin, leukocyte and platelet counts, C-reactive protein, erythrocyte sedimentation rate, fibrinogen). In contrast, SES-CD did not correlate with TFF-3 (P = 0.54). Moreover, TFF-3 levels did not change significantly after therapy irrespectively of whether the patients achieved MH or not. Likewise, TFF-3 did not correlate with changes in fecal calprotectin, which has been proposed as another biochemical marker of mucosal damage in CD.

CONCLUSION

Serum TFF-3 is not a convenient and reliable surrogate marker of MH during therapy with TNF-α antagonists in CD.

Evaluation of inflammatory bowel disease activity in children using serum trefoil factor peptide

BACKGROUND

The diagnosis of IBD and evaluation of treatment require endoscopy, which is difficult in children. This study evaluated the use of TFF3 as a biomarker.

METHODS

Permeability of the intestinal mucosa and serum TFF3 were assayed and colon tissue was harvested 7 days after inducing IBD in mice with TNBSA. TFF3 was monitored in 51 pediatric IBD patients stratified by active disease or remission and in 20 healthy children. Mucosal healing was assessed by the Simple Endoscopic Score for Crohn Disease and Baron scores in CD and UC patients.

RESULTS

Histological evaluation revealed transmural inflammation of the colon in IBD model mice. Permeability of the intestinal mucosa and serum TFF3 were both higher in TNBSA-treated than in control mice (P < 0.05). TFF3 was higher in children with active IBD than in those in remission and in healthy children (P < 0.05). TFF3 was positively correlated with the SES-CD score (P < 0.05) but not with either the pediatric CDAI score or the serum CRP. The sensitivity of serum TFF3 for monitoring CD activity was 100% and the specificity was 76.2%.

CONCLUSIONS

TFF3 level increased with CD activity, which is of significance for diagnosis and for evaluation of mucosal healing. TFF3 could also be a marker in pediatric UC, as TFF3 positively correlated with UCAI.

IMPACT

The diagnosis and evaluation of IBD is difficult; endoscopy provides objective assessment; TFF3 can be a useful marker instead of endoscopy. TFF3 was increased in active CD of children; TFF3 can be used as a clinical marker of pediatric CD; TFF3 can diagnose and evaluate mucosal healing of CD. Pediatrician should pay attention to clinical marker; TFF3 level may be a key evaluation of mucosal healing of CD; the value of diagnosis of TFF3 in CD is important.

Serum levels of 12 renal function and injury markers in patients with glomerulonephritis

INTRODUCTION    Glomerulonephritis (GN) is a complex disease that affects the function of the whole nephron. There are few data on the serum levels of the most common biomarkers of kidney function and injury in GN, or the studies provide ambiguous results. OBJECTIVES    The aim of the study was to evaluate the levels of known kidney-specific and nonspecific markers of renal function or injury in the serum of patients with diagnosed primary or secondary GN, with or without the presence of nephrotic syndrome (NS) and arterial hypertension (AH). PATIENTS AND METHODS    The study included 58 patients with diagnosed GN and 6 patients with congenital defects (CD) of the kidney and AH (CD+AH). The serum levels of β2-microglobulin (β2M), neutrophil‑gelatinase associated lipocalin (NGAL), osteopontin, trefoil factor 3 (TFF-3), calbindin, glutathione-S‑transferase- π (GST-π), interleukin 18 (IL-18), kidney injury molecule 1 (KIM-1), and monocyte chemoattractant protein 1 (MCP-1) were measured with Kidney Toxicity Panels 1 and 2 using the Bio-Plex method. Renalase levels were measured using an enzyme-linked immunosorbent assay. RESULTS    In the whole group and in the subgroups (GN, GN+AH, GN+NS, CD+AH), NGAL, KIM-1, TFF-3, IL-18, β2M, and calbindin levels correlated with estimated glomerular filtration rate (eGFR). In patients with NS, this correlation for calbindin was reversed. Renalase, MCP-1, GST-π, and osteopontin levels were independent of eGFR. Increase in IL-18 levels in the group with GN was assiociated with lower odds of the kidney disease. When this group was divided according to eGFR into subgroups G1-G5, TFF-3, NGAL, and β2M levels increased with the stage of the disease. CONCLUSIONS In patients with NS, renalase and MCP-1 might regulate each other's levels. Further studies are needed to investigate associations between renalase, MCP-1, and osteopontin as factors unrelated to eGFR in GN. NS may contribute to the loss of calbindin from serum. NGAL, KIM-1, TFF-3, IL-18, β2M, and calbindin are good indicators of kidney function loss in patients with GN.

Parasitic helminth infections in humans modulate Trefoil Factor levels in a manner dependent on the species of parasite and age of the host

Helminth infections, including hookworms and Schistosomes, can cause severe disability and death. Infection management and control would benefit from identification of biomarkers for early detection and prognosis. While animal models suggest that Trefoil Factor Family proteins (TFF2 and TFF3) and interleukin-33 (IL-33) -driven type 2 immune responses are critical mediators of tissue repair and worm clearance in the context of hookworm infection, very little is known about how they are modulated in the context of human helminth infection. We measured TFF2, TFF3, and IL-33 levels in serum from patients in Brazil infected with Hookworm and/or Schistosomes, and compared them to endemic and non-endemic controls. TFF2 was specifically elevated by Hookworm infection in females, not Schistosoma or co-infection. This elevation was correlated with age, but not worm burden. TFF3 was elevated by Schistosoma infection and found to be generally higher in females. IL-33 was not significantly altered by infection. To determine if this might apply more broadly to other species or regions, we measured TFFs and cytokine levels (IFNγ, TNFα, IL-33, IL-13, IL-1β, IL-17A, IL-22, and IL-10) in both the serum and urine of Nigerian school children infected with S. haematobium. We found that serum levels of TFF2 and 3 were reduced by infection, likely in an age dependent manner. In the serum, only IL-10 and IL-13 were significantly increased, while in urine IFN-γ, TNF-α, IL-13, IL-1β, IL-22, and IL-10 were significantly increased in by infection. Taken together, these data support a role for TFF proteins in human helminth infection.

Billions of people are infected with parasitic helminths across the globe, especially in resource poor regions. These infections can result in severe developmental delay, disability, and death. Adequate management of helminth infection would benefit from the identification of host biomarkers in easily obtained samples (e.g. serum or urine) that correlate to infection state. Our goal was to determine if specific proteins involved in tissue repair and immune modulation are altered by infection with specific helminth species in Brazil (hookworm and S. mansoni species of blood fluke) or Nigeria (S. haematobium species of blood fluke). One of these proteins, Trefoil Factor 2 (TFF2), was elevated in the serum of hookworm infected women from Brazil, while another, TFF3 is higher in women than men, but also increased by S. mansoni blood fluke infection. In contrast, both TFFs were decreased in the serum of Nigerian children infected by S. haematobium, while many pro-inflammatory cytokines were increased in the urine, where the eggs emerge from host tissue.

Trefoil factor 3 related to gastrointestinal failure in pediatric critical illness

BACKGROUND

To determine the relationship between the serum concentration of trefoil factor 3 (TFF3) and gastrointestinal failure (GIF) in pediatric critical illness in order to provide knowledge for disease management.

MATERIALS AND METHODS

We enrolled 137 cases and divided them into three groups, including a control group (group A), critical illness without GIF (group B), and critical illness with GIF (group C). The serum TFF3 concentration was determined by ELISA and compared among the groups.

RESULTS

Serum TFF3 concentrations measured before the occurrence of GIF in group C were significantly higher than in groups A and B (P<0.01). Under the conditions of GIF in group C, serum TFF3 concentration was significantly related to the gastrointestinal tract function score (r=-0.712). Cox's proportional hazards model analysis showed that the serum TFF3 concentrations at the time of occurrence of GIF, and 48hours later, could be used as prognostic factors in critically ill pediatric patients with GIF (r=1.443 and 1.872, respectively).

CONCLUSION

TFF3 may play an important role in predicting GIF in pediatric critical illness and has a protective function in the mucosal repair process.

Serum Trefoil Factor-3 Predicts Survival in Peripheral Artery Disease

Trefoil factor 3 (TFF3) has been studied in processes leading to atherosclerosis. Data are scarce in manifest disease and missing in peripheral artery disease (PAD). This study aims to elucidate TFF3 with disease stages, degrees of atherosclerosis, and outcomes. TFF3 was measured in serum in 364 PAD patients without critical limb ischemia and mild to moderate chronic kidney disease (CKD). Mortality data were retrieved from the Austrian central death registry (median observation 9.6 years). Survival analyses were performed using Cox regression and the Kaplan-Meier method. A negative association between ankle-brachial index and TFF3 (P < .001) was observed, while levels were similar in asymptomatic and symptomatic PAD. TFF3 increased with history of cardiovascular and cerebrovascular disease (P < .001). TTF3 was associated with the estimated glomerular filtration rate (R = -0.617, P < .001) and urinary albumin-creatinine ratio (R = 0.229, P < .001). One SD increase in TFF3 showed a worsening in all-cause mortality (hazard ratio 1.68, CI 1.37-2.05) which persisted after multiple adjustment for cardiovascular risk, inflammatory, and angiogenetic markers (hazard ratio 1.35, CI 1.01-1.81). This study is the first to link TFF3 with both disease markers and outcomes in PAD. TFF3 demonstrated associations with renal function, PAD severity measured by ankle-brachial index, and additional atherosclerotic burden in PAD.

Prognostic significance of surfactant protein A, surfactant protein D, Clara cell protein 16, S100 protein, trefoil factor 3, and prostatic secretory protein 94 in idiopathic pulmonary fibrosis, sarcoidosis, and chronic pulmonary obstructive disease

BACKGROUND

Identification of serum and bronchoalveolar lavage fluid (BALF) biomarkers may facilitate diagnosis and prognostication in various lung disorders.

OBJECTIVE

Serum and BALF levels of surfactant protein A (SP-A), surfactant protein D (SP-D), Clara cell protein 16 (CC16), S100 protein, trefoil factor 3 (TFF3), and prostatic secretory protein 94 (PSP94) were evaluated in 94 consecutive patients (idiopathic pulmonary fibrosis (IPF; n=18), sarcoidosis (n=25), chronic obstructive pulmonary disease (COPD; n=51)), and in 155 healthy controls.

METHODS

Biomarkers were measured at diagnosis and compared with disease characteristics. Both uniparametric and multiparametric analyses were used.

RESULTS

Seven significant correlations were found: 1) BALF PSP94 level correlated with prognosis of sarcoidosis (P=0.035); 2) BALF SP-D level with pulmonary functions in IPF (P=0.032); 3) BALF SP-D and TFF3 with IPF mortality (P=0.049 and 0.017, respectively); 4) serum TFF3 level with COPD mortality (P=0.006,); 5) serum SP-A with pulmonary functions impairment in IPF (P=0.011); 6) serum SP-D level was associated with HRCT interstitial score in IPF (P=0.0346); and 7) serum SP-A was associated with staging of COPD according to spirometry (P<0.001). Moreover, our analysis showed that some biomarker levels differed significantly among the diseases: 1) BALF SP-D level differed between sarcoidosis and IPF; 2) serum SP-A level differed among IPF, sarcoidosis, COPD and was also different from healthy controls; 3) serum S100A6, S100A11 levels differed among IPF, sarcoidosis, COPD from healthy controls 4) serum SP-D, CC16, TFF-3 levels distinguished IPF patients from healthy controls; and 5) serum CC16, TFF3, PSP94 distinguished COPD patients from healthy controls. Our study shows that some of selected biomarkers should have prognostic value in the analysed lung disorders. On the other hand, these biomarkers do not appear to be unequivocally suitable for differential diagnosis of these disorders.

The diagnostic value of serum trefoil factor 3 and pepsinogen combination in chronic atrophic gastritis: a retrospective study based on a gastric cancer screening cohort in the community population

BACKGROUND

Chronic atrophic gastritis (CAG) is an important precursor of gastric cancer(GC), and there is currently a lack of reliable non-invasive diagnostic markers. This study aims to find a biomarker for non-invasive screening of CAG in the community.

METHODS

A total of 540 individuals were enrolled (test set = 385, validation set = 155). ROC curve analysis was used to evaluate the diagnostic significance of serum Trefoil Factor 3 (TFF3) alone or in combination with pepsinogen (PG) for CAG in the test and validation set. Furthermore, the diagnostic value of TFF3 and PG in different Helicobacter pylori (H. pylori) infection states was studied.

RESULTS

When compared with chronic superficial gastritis (CSG), the expression level of serum TFF3 in the CAG was higher (27 ng/ml vs 19.61, P < 0.001). ROC curve analysis found that the sensitivity, specificity, and area under the curve (AUC) of CAG diagnosis using serum TFF3 alone at the optimal cut-off value of 26.55 ng/ml were 0.529, 0.87, and 0.739, respectively. When TFF3 was combined with The Ratio of PGI to PGII (PGR), the AUC and specificity reached 0.755 and 0.825, respectively. TFF3 individual or combined with PGR had good predictive value, especially in the H. Pylori negative patients.

CONCLUSION

TFF3 combined with PGR can effectively predict CAG, especially in patients with H. pylori negative.

Association of serum trefoil factor 3 and leptin levels with obesity: A case-control study

BACKGROUND

Obesity has a detrimental impact on individuals, communities, and healthcare systems. Trefoil factor 3 is a secretory protein involved in metabolic processes related to weight regulation. However, its relation with obesity is not fully understood.

OBJECTIVE

We aimed to assess the serum trefoil factor 3 level and to immunohistochemical detect the leptin in obese patients to evaluate their relation to obesity pathogenesis.

METHODS

As a case-control study, we enrolled 83 non-obese persons as a control group with a BMI (18.5-24.9) and 83 obese persons as a patient group with a BMI > 30. All the study volunteers are subjected to anthropometric measurements, glucose, and lipid profile analysis by colorimetric methods. Serum trefoil factor 3 level was estimated by ELISA and leptin hormone was detected immunohistochemically in the blood using cell block technique.

RESULTS

ROC curve analysis for TFF3 showed a good relation with obesity with an AUC of 0.891 and a cut-off value of > 96 ng/ml. There was a significant positive correlation between TFF3 and fasting blood sugar, total cholesterol, and triglycerides. The logistic regression analysis showed that TFF3 is a good risk factor for obesity incidence [p = 0.008; OR = 1.117; (95 % CI): 1.029-1.213]. This was confirmed by multiple linear regression that gave an equation for the possibility of predicting BMI using several factors including TFF3 [BMI = 0.821 + 0.051 × TFF3 + 0.044 × FBS + 0.85 × TC]. The more surprising was the ability of the immunohistochemistry cell block technique to detect leptin antigens associated with an obese person blood not only adipose tissue or serum.

CONCLUSION

Leptin hormone and TFF3 could be good indicators for obesity incidence. Further research with a larger sample size and in different populations could completely approve our results.

New serum tumor markers S100, TFF3 and AIF-1 and their possible use in oncogynecology

OBJECTIVE

To review a literature about possible new blood serum gynecologic tumor markers, S100 proteins family, trefoil factor 3 and AIF-1.

DESIGN

Literature review.

SETTING

Department of Obstetrics and Gynecology, Faculty of Medicine, Palacky University and University Hospital in Olomouc.

METHODS

Literature review of articles published in PubMed database till January 2019.

RESULTS

The association of S100A2, S100A4, S100A6, S100A7, S100A8, S100A9 and S100A11 with breast carcinoma has been demonstrated in the literature. The association of S100A2, S100A4, S100A6, S100A7A, S100A10, S100A14, S100A16, S100B, S100P (up-regulation associated with a lower survival) and S100A1, S100A13, S100A5, S100A13 and S100G proteins (up-regulation associated with a better survival) have been demonstrated in ovarian cancer patients. Cervical carcinoma has been shown to be associated with the S100A9 protein. TFF3 association with endometrial cancer, breast cancer (worse prognosis) and ovarian cancer (better prognosis) has been demonstrated. AIF-1 has been shown to increase expression in cervical cancer.

CONCLUSION

Tumor markers can be a very useful tool for patient management when used appropriately. Further research in this area and the search for new tumor markers, including S100, TFF3 and AIF-1, are needed. In future studies, scientists should focus not only on one time point, but assess the trend of the tumor markers for a specific time axis.

Proximity Elongation Assay and ELISA for the Identification of Serum Diagnostic Biomarkers in Parkinson's Disease and Progressive Supranuclear Palsy

Clinical differentiation of progressive supranuclear palsy (PSP) from Parkinson's disease (PD) is challenging due to overlapping phenotypes and late onset of PSP specific symptoms, highlighting the need for easily assessable biomarkers. We used proximity elongation assay (PEA) to analyze 460 proteins in serum samples from 46 PD, 30 PSP patients, and 24 healthy controls. ANCOVA was used to identify the most promising proteins and machine learning (ML) XGBoost and random forest algorithms to assess their classification performance. Promising proteins were also quantified by ELISA. Moreover, correlations between serum biomarkers and biological and clinical features were investigated. We identified five proteins (TFF3, CPB1, OPG, CNTN1, TIMP4) showing different levels between PSP and PD, which achieved good performance (AUC: 0.892) when combined by ML. On the other hand, when the three most significant biomarkers (TFF3, CPB1 and OPG) were analyzed by ELISA, there was no difference between groups. Serum levels of TFF3 positively correlated with age in all subjects' groups, while for OPG and CPB1 such a correlation occurred in PSP patients only. Moreover, CPB1 positively correlated with disease severity in PD, while no correlations were observed in the PSP group. Overall, we identified CPB1 correlating with PD severity, which may support clinical staging of PD. In addition, our results showing discrepancy between PEA and ELISA technology suggest that caution should be used when translating proteomic findings into clinical practice.