Time-resolved Immunofluorometric Assay Research Articles

Development of an immunoassay for quantification of soluble human CD40L (CD154) in plasma and serum samples

When the membrane protein CD40 ligand (CD40L) on activated T cells binds the receptor CD40 on B-cells, it provides a co-stimulatory signal for B cell activation. Dysregulation of the CD40L:CD40 axis is associated with inflammatory and autoimmune diseases. The presence of soluble CD40L (sCD40L) in plasma is implicated in several diseases, from cardiovascular and autoimmune diseases to different types of cancer, and sCD40L has been suggested as a valuable marker of disease. If sCD40L is to be used as a biomarker, being able to precisely measure and quantify the levels of sCD40L in human blood samples is of utmost importance. We demonstrate the development of a sandwich-type time-resolved immunofluorometric assay for quantification of sCD40L in plasma or serum samples. For this, we generate 29 monoclonal anti-CD40L antibodies, and from these, we select the optimal combination of capture antibody and detection antibody. A number of variables were tested: the influence of the type of sample (comparing 3 different blood collection tubes for serum sampling and 4 different types of tubes for plasma sampling), the influence of freeze-thaw cycles, the influence of sampling time during night and day, and the influence of centrifugation of the samples. We found a very similar level of sCD40L in paired EDTA plasma and serum samples. Out of 100 healthy blood donor samples 61 had a level of sCD40L below the detection level of the assay, whereas the remaining 39 samples had ranging levels of sCD40L from 1.14 to 33.14 ng/mL. In summary, we present a time-resolved immunofluorometric assay based on paired monoclonal antibodies, ensuring high specificity, sensitivity, and homogeneity. The Eu3+-based assay additionally provides consistent assay readouts due to the extended decay time not seen in standard enzyme-linked immunosorbent assays. The assay paves the way for specific and consistent quantification of sCD40L in human plasma and serum samples.

Serum vascular adhesion protein-1 is associated with twelve-year risk of incident cancer, cancer mortality, and all-cause mortality: a community-based cohort study.

Vascular adhesion protein-1 (VAP-1), a dual-function glycoprotein, has been reported to play a crucial role in inflammation and tumor progression. We conducted a community-based cohort study to investigate whether serum VAP-1 could be a potential biomarker for predicting incident cancers and mortality. From 2006 to 2018, we enrolled 889 cancer-free subjects at baseline. Serum VAP-1 levels were measured using a time-resolved immunofluorometric assay. Cancer and vital status of the participants were obtained by linking records with the computerized cancer registry and death certificates in Taiwan. During a median follow-up of 11.94 years, 69 subjects developed incident cancers and 66 subjects died, including 29 subjects who died from malignancy. Subjects in the highest tertile of serum VAP-1 had a significantly higher risk of cancer incidence (p=0.0006), cancer mortality (p=0.0001), and all-cause mortality (p=0.0002) than subjects in the other tertiles. The adjusted hazard ratios per one standard deviation increase in serum VAP-1 concentrations were 1.28 for cancer incidence (95% CI=1.01-1.62), 1.60 for cancer mortality (95% CI=1.14-2.23), and 1.38 for all-cause mortality (95% CI=1.09-1.75). The predictive performance of serum VAP-1 was better than that of gender, smoking, body mass index, hypertension, diabetes, and estimated glomerular filtration rate but lower than that of age for cancer incidence, cancer mortality, and all-cause mortality, as evidenced by higher increments in concordance statistics and area under the receiver operating characteristic curve. Serum VAP-1 levels are associated with a 12-year risk of incident cancer, cancer mortality, and all-cause mortality in a general population.

Platelets and the Lectin Pathway of Complement Activation in Patients with Systemic Lupus Erythematosus or Antiphospholipid Syndrome.

Background Patients with systemic lupus erythematosus (SLE) have an increased risk of thrombosis even when they do not have antiphospholipid syndrome (APS). Interactions between complement activation and activated platelets have been suggested in SLE and APS and could play a role in the increased thrombosis risk. Objectives To explore factors potentially related to the prothrombotic pathophysiology in patients with SLE, primary APS, and healthy controls, by investigating lectin pathway proteins (LPPs), complement activation, platelet aggregation, and platelet activation. Methods This cross-sectional cohort study included 20 SLE patients, 17 primary APS, and 39 healthy controls. Flow cytometry and light transmission aggregometry were used to assess platelet activation and aggregation. Using time-resolved immunofluorometric assays, the plasma concentrations of 11 LPPs and C3dg, reflecting complement activation, were measured. Results H-ficolin plasma concentrations were higher in SLE and APS patients than in controls ( p = 0.01 and p = 0.03). M-ficolin was lower in SLE than in APS ( p = 0.01) and controls ( p = 0.03). MAp19 was higher in APS patients than in SLE patients ( p = 0.01) and controls ( p < 0.001). In APS patients, MASP-2 and C3dg correlated negatively with platelet activation. Platelet-bound fibrinogen after agonist stimulation and C3dg concentrations correlated negatively with platelet activation. Conclusion We observed significant differences between SLE and APS patients regarding complement proteins and platelet activation. Particularly the negative correlations between MASP-2 and C3dg with platelet activation only observed in APS patients suggest that interactions between complement activation and platelets differ in SLE and APS.

Diagnostic accuracy of anti-DGP (IgG) for celiac disease.

Celiac disease (CD) is an autoimmune enteropathy that is caused by the intake of gluten-containing grains in genetically susceptible humans. The gliadin and glutenin parts of wheat gluten are the essential factors that cause intestinal damage. We analyzed the performance of a time-resolved immunofluorometric assay (TR-IFMA) in the diagnosis of CD in children. For this purpose, we compared the performance of IgA anti-tissue transglutaminase antibodies (IgA anti-TTG) and IgG antibodies against deamidated gliadin peptides (IgG anti-DGP) for the diagnosis of CD. In this cross-sectional study conducted in 2021 for a duration of about 6 months, 200 patients with suspected CD symptoms, children who needed screening due to Down syndrome or Turner syndrome, and the first-degree relatives of CD patients who underwent diagnostic evaluation were enrolled in a census study. This study compares existing point-of-care anti-DGP Ab (IgG) and anti-TTG Ab (IgA) tests against each other using the gold standard of duodenal biopsy and pathology. Serology as a screening test was acceptable (93.6% for anti-DGP vs. 94.2% for anti-TTG) for both of them. This equivalent sensitivity of serum TTG and the DGP tests validates its potential as a basic tool for serological testing. Furthermore, endoscopy is carried out in patients positive for both. Our study showed that for the diagnosis of CD, anti-DGP antibodies had comparable characteristics with anti-TTG (IgA) in terms of diagnostic specificity and sensitivity. Specify of anti-DGP was higher than that of anti-TTG.

Immunoassay for detection of oligomeric proteins

The mass concentration of specific proteins is often used as a biomarker and play an important part in diagnostics of inflammatory diseases. Monodisperse proteins are robustly measured in immunoassays, but it is considerably more complicated to measure polydisperse oligomeric proteins. The degree of protein oligomerization is critical for functional aspects. For such proteins, information on both the mass concentration as well as the degree of oligomerization is important. Here, a time-resolved immunofluorometric assay (TRIFMA) with sensitivity for protein structure to detect homo-oligomeric and polydisperse proteins is presented. An established TRIFMA for mannan-binding lectin (MBL) was modified by implementing an additional blocking step prior to coating with capture antibodies, leading to a decrease in coating density. Recombinant human MBL was sorted into small, intermediate, and large complexes, using gel permeation chromatography. Small MBL complexes were poorly detectable by TRIFMA with a sparse antibody coating, while larger complexes produced a strong response. From comparison of molecular dimensions, this difference can be related to the size of oligomers. In conclusion, it is possible to design oligomer-size-sensitive immunoassays by regulating the inter-molecular distance of capture antibodies on a scale comparable to the size of the oligomers.

Insights into Preservation of Blood Biomarkers in Biobank Samples.

Insights into Preservation of Blood Biomarkers in Biobank Samples.

Measurement and clinical applications of C-reactive protein in gastrointestinal diseases of dogs.

C‐reactive protein (CRP) is a positive acute‐phase protein, serum concentrations of which increase nonspecifically in response to inflammatory processes of the dog. As such, it can aid in the identification of inflammatory disease and, maybe more importantly, the objective monitoring of disease progression. In dogs, CRP is frequently used to evaluate dogs with gastrointestinal diseases, such as chronic inflammatory enteropathies (also termed idiopathic inflammatory bowel disease), acute pancreatitis, canine parvovirus infection, hepatic disease, acute abdomen, and protein‐losing enteropathy. The diversity of the assays available to measure CRP in dogs is nearly as numerous as the diseases in which serum concentrations of this protein are increased. Assay methodologies include laser nephelometric immunoassays, enzyme‐linked immunosorbent assays, immunoturbidimetric assays, and time‐resolved immunofluorometric assays. While many of these assays are acceptable for clinical use in the dog, the same assay and analyzer should be used to measure a patient's CRP concentration longitudinally. By looking at the uses of CRP in human gastroenterology, including reducing the duration of antibiotic therapy, the veterinary profession can gain insight into novel ways in which serum CRP concentration measurements might be applied in veterinary medicine in the future.

TATI, TAT-2, and CRP as Prognostic Factors in Colorectal Cancer

Objectives: Colorectal cancer is the third most common cancer worldwide, with an obvious need for more accurate prognostics. Previous studies identified C-reactive protein (CRP) as a prognostic serum biomarker for colorectal cancer, whereas the biomarkers tumor-associated trypsin inhibitor (TATI) and tumor-associated trypsin-2 (TAT-2) are less well-known prognostic factors. Therefore, in this study, we aimed to compare the prognostic role of these biomarkers. Materials and Methods: Our cohort consisted of 219 women and 274 men who underwent colorectal cancer surgery at Helsinki University Central Hospital from 1998 through 2005. Serum and plasma samples were collected before surgery, aliquoted, stored at −80°C, and then analyzed using high-sensitivity methods with commercially available time-resolved immunofluorometric assay kits. Results: In univariate analysis, CRP (HR 1.67; 95% confidence interval [CI]: 1.25–2.23; p = 0.001), TATI (HR 1.87; 95% CI: 1.13–3.08; p = 0.014), and TAT-2 (HR 1.52; 95% CI: 1.13–2.06; p = 0.006) were significant prognostic biomarkers across the entire cohort. In subgroup analyses, TATI and TAT-2 represented significant negative prognostic factors among patients older than 66, while patients with left-sided disease, a high serum TAT-2, or a high plasma CRP experienced worse prognosis. None of the biomarkers emerged as important in the disease stage subgroup analysis nor did they serve as independent factors in the multivariate analysis. Conclusions: TATI and TAT-2 as well as CRP significantly, but not independently, served as prognostic factors in our cohort of colorectal cancer patients. Further research is needed to fully understand their clinical role in colorectal cancer.

Patients with Primary Central Nervous System Lymphoma Have High Levels of Soluble Programmed Cell Death Protein 1 in Their Pretherapeutic Cerebrospinal Fluid

§ s hared first authorship; §§ s hared last authorshipPrimary Central Nervous System Lymphoma (PCNSL) is a rare and aggressive non-Hodgkin lymphoma with limited treatment options and severe prognosis. It may display copy number abnormalities of the 9p24.1 locus harboring the programmed cell death protein ligand 1 (PD-L1) gene. Moreover, tumor lesions often overexpress programmed cell death protein 1 (PD-1) as well as its ligands (PD-L1/PD-L2). Soluble forms of these molecules have been demonstrated in serum and plasma, though the biological and clinical significance of these soluble checkpoint proteins is yet unclear. Furthermore, their presence in the cerebrospinal fluid (CSF), particularly in malignant diseases, is largely unexplored. Thus, the aim of our study was to measure the occurrence of soluble PD-1 (sPD-1) in the CSF of PCNSL patients.We measured sPD-1 levels in pretherapeutic plasma and CSF samples from 11 patients with histopathologically confirmed PCNSL of diffuse large B-cell type (DLBCL) and five patients in which the histopathological examination did not confirm the initial clinical and imaging-based suspicion of PCNSL diagnosis (non-PCNSL). All blood and CSF samples were obtained prior to neurosurgical biopsy. Of these five patients, four had reactive non-malignant lesions and one a glioblastoma. Six CSF samples routinely screened for non-malignant neurological disease (e.g. sclerosis) were included as an additional non-PCNSL control group (neuro-screen samples). All samples were handled identically prior to analysis. Soluble PD-1 was measured using an in-house time-resolved immunofluorometric assay (TRIFMA) as previously reported by our group (Mortensen JB et al. Eur J Haematol. 2021 Jul;107:81-91). All samples were analyzed in duplicates. The TRIFMA was validated for freeze/thaw interference and recovery.We found that pretherapeutic CSF sPD-1 levels in PCNSL patients were approximately 10 to 30-fold higher than those of non-PCNSL and neuro-screen patients (p<0,001). The median CSF sPD-1 level for PCNSL was 628 pg/mL, while the corresponding values for the non-PCNSL and neuro-screen subgroups were 48 pg/mL and 19 pg/mL, respectively. Fig. 1a shows the sPD-1 values measured in the three different subsets (PCNSL, non-PCNSL, neuro-screen) of the study cohort. Three PCSNL patients had particularly high sPD-1 values (range: 1642-2194 pg/mL) in their pretherapeutic CSF samples. Interestingly, these three patients all displayed ‘high-risk’ molecular features, i.e., one case of double-overexpression of bcl-6 and c-Myc and the only two cases of triple-overexpression of bcl-2, bcl-6 and c-Myc. In all 11 PCNSL patients, the DLBCL histology had an activated B-cell like (ABC)/non-germinal center B-cell like (non-GCB) signature. Plasma samples were only available for the PCNSL and non-PCNSL subsets. The median plasma sPD-1 value was 142 pg/mL and 124 pg/mL, respectively. As opposed to non-PCNSL, the CSF sPD-1 levels of PCNSL patients were higher than the paired plasma values (p<0.001; Fig.1b). TRIFMA based measurement of sPD-L1/2 in all available CSF samples and genomic analyses of pretherapeutic PCNSL tissue biopsies are ongoing.At the time of analysis, the median follow-up of the PCNSL cohort was 17 months (range: 1-47) with three deaths observed at 1, 2 and 4 months, respectively. Among the remaining eight patients, six are in continuous 1st complete remission (CR) and two in 2nd CR. Of the six patients in 1st CR, four underwent consolidation with upfront autologous transplant. So far, no significant correlation between CSF sPD-1 and survival has been observed.Despite the limited size of our cohort, we demonstrated that sPD-1 is present and measurable in the CSF of previously untreated PCNSL patients. Moreover, we observed that sPD-1 levels in the pretherapeutic CSF samples from PCNSL were significantly higher than those measured in the non-PCNSL and neuro-screen samples. The PCNSL patients with the most adverse histological features were also the ones with the highest sPD-1 levels in the pretherapeutic CSF. Confirmation of these findings in a larger independent cohort as well as sequential measurements obtained during the course of the disease are warranted. If confirmed, our observations may help to evaluate the usefulness of CSF sPD-1 measurements with regard to disease monitoring as well as checkpoint inhibition strategies in PCNSL. [Display omitted] DisclosuresPulczynski: Investigator of a clinical trial (Nordic Lymphoma Group NLG- LBC7(Polar Bear) EudraCT No 2018- 0038 funded by Roche: Research Funding.

M-ficolin: a valuable biomarker to identify leukaemia from juvenile idiopathic arthritis

ObjectiveDistinction on clinical grounds between acute lymphoblastic leukaemia presenting with arthropathy (ALLarthropathy) and juvenile idiopathic arthritis (JIA) is difficult, as the clinical and paraclinical signs of leukaemia may be vague....

The Relationship between the Tissue Expression of TLR2, TLR4, TLR5, and TLR7 and Systemic Inflammatory Responses in Colorectal Cancer Patients

Background: Colorectal cancer (CRC) is the third most commonly diagnosed malignancy globally. CRC patients with elevated plasma C-reactive protein (CRP) levels exhibit compromised prognoses. Toll-like receptors (TLRs), activating the innate and adaptive immune systems, may contribute to pro- and antitumorigenic inflammatory responses. We aimed to identify a possible link between local and systemic inflammatory responses in CRC patients by investigating the association between tissue TLRs and plasma CRP. Methods: Tissue expressions of TLR2, TLR4, TLR5, and TLR7 were assessed using immunohistochemistry of tissue microarray slides from 549 CRC patients surgically treated between 1998 and 2005. Blood samples were drawn preoperatively, centrifuged, aliquoted, and stored at −80°C until analysis. Plasma CRP was determined through high-sensitivity time-resolved immunofluorometric assay. We investigated the association of TLRs to clinicopathologic variables, plasma CRP, and survival. Results: High TLR2 expression (hazard ratio [HR] 0.59; 95% confidence interval [CI] 0.41–0.85; p = 0.005), high TLR5 expression (HR 0.60; 95% CI 0.45–0.83; p = 0.002), positive TLR7 expression (HR 0.49; 95% CI 0.33–0.72; p < 0.001), and low CRP (HR 1.48; 95% CI 1.08–2.11; p = 0.017) were associated with a better prognosis. A high TLR2 immunoexpression was associated with a better prognosis among low-CRP patients (HR 0.53; 95% CI 0.35–0.80; p = 0.002), high TLR4 expression among high-CRP patients (HR 2.04; 95% CI 1.04–4.00; p = 0.038), high TLR5 expression among low-CRP patients (HR 0.059; 95% CI 0.37–0.92; p = 0.021), and positive TLR7 expression among low-CRP patients (HR 0.53; 95% CI 0.28–1.00; p = 0.049). In multivariate analyses, no biomarkers emerged as significant independent variables. Conclusions: High tissue TLR2, TLR5, and TLR7 levels were associated with a better prognosis. Among low-CRP patients, those with high TLR2, TLR5, and TLR7 immunoexpressions exhibited a better prognosis. Among high CRP patients, a high TLR4 immunoexpression was associated with a better prognosis.

Active MMP-8 Quantitative Test as an Adjunctive Tool for Early Diagnosis of Periodontitis.

Periodontitis is a host-mediated bacterial disease that affects the tooth attachment apparatus. Metalloproteinase-8 (MMP-8), a validated biomarker, could aid in clinical diagnosis. This study aimed to evaluate the diagnostic performance of active (a) MMP-8 immunotest versus total (t) MMP-8 ELISA for quantitative real-time diagnosis and assessment of periodontitis severity at the site level. Gingival crevicular fluid (GCF) was sampled from 30 healthy, 42 mild, and 59 severe periodontitis sites from thirty-one volunteers. MMP-8 concentrations were determined by time-resolved immunofluorometric assay (IFMA) and enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using the STATA package. Both active and total MMP-8-based methods discriminated among sites according to periodontal diagnosis and severity, with a positive correlation between the two tests (p < 0.001). (a) MMP-8 models showed the best performance in receiver operating characteristic (ROC) curves to discriminate between healthy and periodontitis sites (area under the curve [AUC] = 0.89), while (t) MMP-8 demonstrated a high diagnostic precision in the detection of mild from severe periodontitis sites (AUC ≥ 0.80). The use of (a) MMP-8 and (t) MMP-8 could represent a useful adjunctive tool for periodontitis diagnosis and severity. These results support the applicability of new point-of-care methods in the monitoring of high-risk periodontal patients.

Low association between bleeding on probing propensity and the salivary aMMP-8 levels in adolescents with gingivitis and stage I periodontitis.

Bleeding on probing (BOP) is a widely accepted measure used in periodontal diagnostics. Previous studies suggest that several factors can affect BOP propensity. The aim of this study was to investigate the relative impact of different local and modifying factors on BOP levels. The oral health of five hundred and forty-four adolescents (two birth cohorts) aged 15-17years living in Kotka, Finland, was examined including periodontal probing depth, visible plaque index, root calculus, and BOP. Whole saliva samples were collected and measured for active matrix metalloproteinase-8 (aMMP-8) by time-resolved immunofluorometric assay (IFMA). Bacterial plaque/calculus accumulation (oral hygiene) had a major influence on BOP levels. The relative impact was several times greater compared with the extent of periodontal pocketing, aMMP-8 levels, smoking, toothbrushing, or gender. Furthermore, BOP levels were significantly elevated among adolescents with poor oral hygiene than good oral hygiene even if adjusted for the extent of periodontal pocketing (P<.001). BOP levels could be low even if several≥4mm deep periodontal pockets existed. The difference in the extent of periodontal pocketing was not significant between the two birth cohorts of adolescents (P=.731). BOP levels can be regarded as an important indicator of the extent of bacterial challenge and its adverse effects on the gingival inflammation. However, the level of oral hygiene may mask the association between the extent of gingival bleeding and the severity of the periodontal inflammatory condition. Thus, relying on BOP levels (below 10% or 20%) may provide insufficient information about the periodontal treatment need of an adolescent depending on his/her level of oral hygiene. Yet, more research is needed to confirm the results, also in adult populations.

High Expression of MMP-9 in Primary Tumors and High Preoperative MPO in Serum Predict Improved Prognosis in Colorectal Cancer with Operable Liver Metastases

Introduction: The liver metastases of colorectal cancer (CRC) can be surgically treated in selected cases, with continuously improving results. Matrix metalloproteinases (MMPs) contribute to cancer invasion by degrading the extracellular matrix, and elevated levels of MMP-2, MMP-8, and MMP-9 have been detected in several malignancies. Myeloperoxidase (MPO) is a mediator of tissue damage that can oxidatively activate latent MMPs. We evaluated the prognostic value of MMP-2, MMP-8, and MMP-9 in tissue samples of primary tumors and liver metastases and the pre- and postoperative serum levels of MMP-8, MMP-9, and MPO in CRC patients undergoing liver resection. Methods: Tissue and serum samples were obtained from 111 patients who had primary colorectal tumors and their liver metastases surgically treated at the Helsinki University Hospital between 1988 and 2007. Tissue expression of MMP-2, MMP-8, and MMP-9 in primary tumors and liver metastases was evaluated by immunohistochemistry. Pre- and postoperative serum concentrations of MMP-8, MMP-9, and MPO were determined using a time-resolved immunofluorometric assay or commercially available enzyme-linked immunosorbent assay kits. Clinical data were retrieved from patient records and the Central Statistical Office of Finland. Associations with disease-free survival (DFS) and overall survival (OS) were estimated using Cox regression analysis and the Kaplan-Meier method. Results: High expression of MMP-9 in colorectal tumor tissue was associated with better DFS (p = 0.010), and high preoperative MPO in serum with improved DFS and OS (p < 0.001 and p = 0.014, respectively). The prognostic significance varied according to gender, age, and the synchronicity of liver metastases. Conclusion: Low preoperative MPO in serum might identify patients at high risk of recurrence and death after resection of colorectal liver metastases. Elevated preoperative MPO and high expression of MMP-9 in colorectal tumor tissue indicate an improved prognosis. The use of these biomarkers should be adjusted according to clinical characteristics.

Proteins of the Lectin Pathway of complement activation at the site of injury in subarachnoid hemorrhage compared with peripheral blood.

BackgroundA subarachnoid hemorrhage (SAH) is a debilitating stroke. Activation of the lectin pathway (LP) of the complement system in SAH patients could worsen the prognosis; however, conflicting results have been reported. This potentially reflects that pathological changes at the site of injury are not reflected in peripheral blood.Aims of the studyTo measure the concentration of LP proteins in blood from the site of brain injury compared with peripheral blood in SAH patients, and to determine the concentration of LP proteins in cerebrospinal fluid (CSF).MethodsWe included 11 SAH patients undergoing aneurysm clipping or external ventricular drainage. Blood was collected from the site of injury and from a peripheral artery and/or CSF simultaneously. LP proteins were measured using time‐resolved immunofluorometric assays.ResultsIn all patients, the cerebral blood concentration of mannan‐binding lectin, collectin liver‐1 and collectin kidney‐1, and mannan‐associated serine proteases 1 and 2 were lower than in peripheral blood. The LP proteins were almost undetectable in CSF.ConclusionLectin pathway protein concentrations measured in peripheral blood do not always reflect changes at the site of injury. For some proteins, more information could be obtained in blood from the site of injury when investigating pathogenic mechanisms.

Tumor-associated trypsin inhibitor (TATI) and tumor-associated trypsin-2 (TAT-2) predict outcomes in gastric cancer

Introduction: Tumor-associated trypsin inhibitor (TATI) limits serine proteases, promotes carcinogenesis in several cancers and functions as an acute-phase reactant. Tumor-associated trypsin-2 (TAT-2), a proteolytic target enzyme for TATI, can enhance invasion by promoting extracellular matrix degradation. Here, we aimed to study serum TATI and TAT-2 levels, including the TAT-2/TATI ratio, as prognostic and diagnostic biomarkers in gastric cancer. We compared the results with the plasma level of C-reactive protein (CRP).Material and Methods: We selected 240 individuals operated on for gastric adenocarcinoma at the Helsinki University Hospital, Finland, between 2000 and 2009. We determined the preoperative serum TAT-2, TATI and plasma CRP levels using time-resolved immunofluorometric assays using monoclonal antibodies.Results: The medium serum TAT-2 level was higher among gastric cancer patients [8.68 ng/ml; interquartile range (IQR) 5.93–13.2] than among benign controls (median 5.41 ng/ml; IQR 4.12–11.8; p = .005). Five-year survival among patients with a high serum TAT-2 was 22.9% [95% confidence interval (CI) 11.7–34.1], compared to 52.2% (95% CI 44.6–59.8; p < .001) among those with a low level. The five-year survival among patients with a high serum TATI was 30.6% (95% CI 20.4–40.8), compared to 52.9% (95% CI 44.7–61.1; p < .001) among those with a low level. The serum TATI level remained significant in the multivariable survival analysis (hazard ratio 2.01; 95% CI 1.32–3.07). An elevated plasma CRP level associated with a high serum TATI level (p = .037).Conclusions: This study shows for the first time that a high serum TAT-2 may function as a prognostic biomarker in gastric cancer and that TAT-2 levels may be elevated compared to controls. Additionally, we show that the prognosis is worse among gastric cancer patients with a high serum TATI. These biomarkers serve as prognostic factors particularly among patients with a metastatic or a locally advanced disease.

Simulated Microgravity Influences VEGF, MAPK, and PAM Signaling in Prostate Cancer Cells.

Prostate cancer is one of the leading causes of cancer mortality in men worldwide. An unusual but unique environment for studying tumor cell processes is provided by microgravity, either in space or simulated by ground-based devices like a random positioning machine (RPM). In this study, prostate adenocarcinoma-derived PC-3 cells were cultivated on an RPM for time periods of 3 and 5 days. We investigated the genes associated with the cytoskeleton, focal adhesions, extracellular matrix, growth, survival, angiogenesis, and metastasis. The gene expression of signaling factors of the vascular endothelial growth factor (VEGF), mitogen-activated protein kinase (MAPK), and PI3K/AKT/mTOR (PAM) pathways was investigated using qPCR. We performed immunofluorescence to study the cytoskeleton, histological staining to examine the morphology, and a time-resolved immunofluorometric assay to analyze the cell culture supernatants. When PC-3 cells were exposed to simulated microgravity (s-µg), some cells remained growing as adherent cells (AD), while most cells detached from the cell culture flask bottom and formed multicellular spheroids (MCS). After 3-day RPM exposure, PC-3 cells revealed significant downregulation of the VEGF, SRC1, AKT, MTOR, and COL1A1 gene expression in MCS, whereas FLT1, RAF1, MEK1, ERK1, FAK1, RICTOR, ACTB, TUBB, and TLN1 mRNAs were not significantly changed. ERK2 and TLN1 were elevated in AD, and FLK1, LAMA3, COL4A5, FN1, VCL, CDH1, and NGAL mRNAs were significantly upregulated in AD and MCS after 3 days. After a 5-day culture in s-µg, the PC-3 cells showed significant downregulations of VEGF mRNA in AD and MCS, and FN1, CDH1, and LAMA3 in AD and SCR1 in MCS. In addition, we measured significant upregulations in FLT1, AKT, ERK1, ERK2, LCN2, COL1A1, TUBB, and VCL mRNAs in AD and MCS, and increases in FLK1, FN1, and COL4A5 in MCS as well as LAMB2, CDH1, RAF1, MEK1, SRC1, and MTOR mRNAs in AD. FAK1 and RICTOR were not altered by s-µg. In parallel, the secretion rate of VEGFA and NGAL proteins decreased. Cytoskeletal alterations (F-actin) were visible, as well as a deposition of collagen in the MCS. In conclusion, RPM-exposure of PC-3 cells induced changes in their morphology, cytoskeleton, and extracellular matrix protein synthesis, as well as in their focal adhesion complex and growth behavior. The significant upregulation of genes belonging to the PAM pathway indicated their involvement in the cellular changes occurring in microgravity.

Regulation of Salivary Peptidoglycan Recognition Protein 1 in Adolescents.

Peptidoglycan recognition protein 1 (PGLYRP1), a member of peptidoglycan recognition proteins, is known to be involved in the proinflammatory response toward bacterial infections. Recently, PGLYRP1 was identified as a ligand for triggering receptor expressed on myeloid cells 1 (TREM-1). Although PGLYRP1 is involved in immune and inflammatory responses, its levels in initial stages of periodontal disease in adolescents are currently unknown. We aimed to investigate salivary levels of PGLYRP1 and its correlation with TREM-1, polymorphonuclear leukocyte elastase (PMN elastase), and an active matrix metalloproteinase 8 (aMMP-8) in adolescents. Whole saliva samples (n = 537) were collected from 15- to 16-y-old adolescents at Kotka Health Center, Finland, prior to periodontal examination, including measurement of periodontal pocket depth (PPD), visible plaque index (VPI), and bleeding on probing (BOP). Adolescents, clustered as periodontally healthy, gingivitis, or subclinical periodontitis, were tested for salivary levels of TREM-1, PGLYRP1, and PMN elastase by enzyme-linked immunosorbent assay and aMMP-8 by a time-resolved immunofluorometric assay (IFMA). Salivary levels of PGLYRP1 and aMMP-8 were significantly higher in adolescents with subclinical periodontitis and gingivitis compared to individuals with healthy periodontium. TREM-1 and PMN elastase levels were higher in adolescents with subclinical periodontitis compared to healthy individuals but did not reach significance. PGLYRP1 correlated positively with BOP, PPD, VPI, aMMP-8, and TREM-1. Elevated PGLYRP1 levels in adolescents with gingivitis and subclinical periodontitis and its positive correlation with TREM-1 and aMMP-8 may indicate an association of PGLYRP1 with initial stages of periodontal disease. Sex and poor oral hygiene but not smoking are also associated with higher levels of PGLYRP1. However, PGLYRP1 has a lower discriminating capacity and is therefore a less reliable marker alone in the diagnosis of initial stages of periodontal disease in adolescents. PGLYRP1, a member of peptidoglycan recognition proteins, is a ligand for TREM-1. Elevated PGLYRP1 levels in adolescents with gingivitis and subclinical periodontitis and its positive correlation with TREM-1 and aMMP-8 may indicate an association of PGLYRP1 with initial stages of periodontal disease. However, it has a lower discriminating capacity and is therefore a less reliable marker alone in the diagnosis of periodontal disease in adolescents.

One-year follow-up of anti-Leishmania antibody concentrations in serum and saliva from experimentally infected dogs

The quantification of anti-Leishmania antibodies in serum and saliva by a time-resolved immunofluorometric assay is useful for the diagnosis and treatment monitoring of dogs with clinical leishmaniasis. We compared the kinetics of anti-Leishmania IgG2 and IgA antibodies in serum and saliva from 11 Beagle dogs experimentally infected with Leishmania infantum. Most dogs showed detectable concentrations of anti-Leishmania IgG2 earlier in serum (between 3 and 4 months p.i.) than in saliva (between 4 and 6 months p.i.). Overall, a high correlation between concentrations of anti-Leishmania IgG2 in serum and saliva (r = 0.853; P < 0.0001) was observed. The quantification of anti-Leishmania IgA showed less diagnostic value than IgG2, since detectable amounts of IgA were not observed in the saliva of four dogs and in the serum of one dog. In addition, a very low correlation between anti-Leishmania IgA in serum and saliva (r = 0.289; P < 0.001) was observed. Our results indicate that the antibodies against L. infantum in saliva appear approximately 1 month later than in serum, and suggest that there is a threshold for the passing of immunoglobulins from serum to saliva in dogs. These facts should be taken into consideration for a proper interpretation of saliva assays for quantification of antibodies.

Pattern Recognition Molecules of the Lectin Pathway-Screening of Patients with Suspected Immunodeficiency.

To compare plasma concentrations of all lectin pathway (LP) pattern recognition molecules (PRMs) in patients referred for laboratory evaluation due to recurrent infections with healthy individuals. Patients were divided into categories according to referral: recurrent airway infections (RAI), recurrent abscesses, common variable immunodeficiency (CVID), lung transplantation candidates (LTX), and 'other causes'. LP PRMs (mannose-binding lectin (MBL), collectin liver 1 (CL-L1), H-ficolin, L-ficolin, M-ficolin) and C-reactive protein (CRP) were determined in 332 patients and 150 healthy blood donors using time-resolved immunofluorometric assays. None of the LP PRMs was found in lower concentration in the patient categories; however, several PRMs were detected in higher concentrations. M-ficolin was found in higher concentrations in all patient categories. Patients suffering from RAI had higher concentrations of CL-L1 and H-ficolin. Patients suffering from abscesses exhibited higher concentrations of MBL and CL-L1, whereas LTX had higher concentrations of MBL. Patients with other causes of referral had higher concentrations of MBL and CL-L1. Prevalence of combined deficiencies of PRMs in patient categories and controls did not differ. CRP was used as a marker of ongoing inflammation and was significantly higher among all patient categories. Furthermore, CRP was found to correlate with both M-ficolin and L-ficolin. The results suggest that neither single nor combined deficiencies of LP PRMs are more frequent among patients referred for an immunological evaluation than in healthy individuals. Future studies are needed and should focus on deficiencies of LP PRMs combined with deficiencies in other parts of the immune system.