Inherited and acquired determinants of serum tryptase levels in humans.

OBJECTIVE: To aid the clinician in correctly interpreting serum tryptase levels. DATA SOURCES: Primary peer-reviewed literature. STUDY SELECTIONS: Clinical and basic science peer-reviewed studies characterizing the genetic and physiological bases for tryptase generation, secretion, and elevation, including those describing serum tryptase levels in population-based cohort studies. RESULTS: Clinically measured basal serum tryptase (BST) consists of ostensibly inactive alpha- and beta-tryptase precursors. The autosomal dominant genetic trait hereditary alpha-tryptasemia is the most often cause for elevated BST levels, with other acquired causes, such as renal failure and clonal myeloid diseases being far less common. Acute increases in serum tryptase levels resulting from release of mature tryptase from secretory granules is specific to mast cell degranulation but is not detected in all cases of systemic anaphylaxis. CONCLUSION: Understanding the differences and distinguishing between acute increases in serum tryptase and chronic elevations in BST owing to inherited or acquired conditions is critical in the correct interpretation of this useful clinical biomarker.

Increased pro-MMP9 plasma levels are associated with neovascular age-related macular degeneration and with the risk allele of rs142450006 near MMP9.

Purpose: To evaluate the plasma levels of matrix metalloproteinase 9 (MMP9) and tissue inhibitors of metalloproteinase 3 (TIMP3) in neovascular age-related macular degeneration (nAMD) patients compared to controls, and to explore the potential effect of AMD-associated genetic variants on MMP9 and TIMP3 protein levels. Methods: nAMD and control patients were selected from the European Genetic Database (EUGENDA) based on different genotypes of rs142450006 near MMP9 and rs5754227 near TIMP3. Plasma total MMP9, active MMP9 and TIMP3 levels were measured using the enzyme linked immunosorbent assay (ELISA) and compared between nAMD patients and controls, as well as between different genotype groups. Results: nAMD patients had significantly higher total MMP9 levels compared to controls (median 46.58 versus 26.90 ng/ml; p = 0.0004). In addition, the median MMP9 level in the homozygous genotype group for the AMD-risk allele (44.23 ng/ml) was significantly higher than the median for the heterozygous genotype group (26.90 ng/ml; p = 0.0082) and the median for the homozygous group for the non-risk allele (28.55 ng/ml; p = 0.0355). No differences were detected for the active MMP9. TIMP3 levels did not significantly differ between the AMD and control groups, nor between the different genotype groups for rs5754227. Conclusions: The results of our MMP9 analyses indicate that nAMD patients have on average higher systemic MMP9 levels than control individuals, and that this is partly driven by the rs142450006 variant near MMP9. This finding might be an interesting starting point for further exploration of MMP9 as a therapeutic target in nAMD, particularly among individuals carrying the risk-conferring allele rs142450006.

Pro-cathepsin D as a diagnostic marker in differentiating malignant from benign pleural effusion: a retrospective cohort study.

BACKGROUND: Malignant pleural effusion (MPE) causes substantial symptomatic burden in advanced malignancy. Although pleural fluid cytology is a commonly accepted gold standard of diagnosis, its low diagnostic yield is a challenge for clinicians. The aim of this study was to determine whether pro-cathepsin D can serve as a novel biomarker to discriminate between MPE and benign pleural effusion (BPE). METHODS: This study included 81 consecutive patients with exudative pleural effusions who had underwent thoracentesis or pleural biopsy. Pleural fluid and serum were collected as a standard procedure for all individuals at the same time. The level of pro-cathepsin D was measured by the sandwich enzyme-linked immunosorbent assay method. RESULTS: Though there were no significant differences in plasma pro-cathepsin D between the two groups, the level of pleural fluid pro-cathepsin D was significantly higher in the MPE group than the BPE group (0.651 versus 0.590 pg/mL, P = 0.034). The discriminative power of pleural fluid pro-cathepsin D for diagnosing MPE was moderate, with 81% sensitivity and 53% specificity at a pro-cathepsin D cut-off ≥0.596 pg/mL (area under the curve: 0.656). Positive and negative predictive values for MPE were 38 and 89%, respectively, with pro-cathepsin D cut-off value (> 0.596 pg/mL). CONCLUSIONS: The level of pleural fluid pro-cathepsin D was found to be significantly higher in MPE than in BPE. Although results of this study could not support the sole use of pleural fluid pro-cathepsin D to diagnose MPE, pleural fluid pro-cathepsin D can be added to pre-existing diagnostic methods for ruling-in or ruling-out MPE.

Dietary Protein and Carbohydrates Affect Immune Function and Performance in a Specialist Herbivore Insect (Manduca sexta).

Nutrition structures ecology and evolution across all scales of biological organization. It is well known that nutrition can have direct effects on performance and fitness, but indirect effects on physiological systems that mediate biotic interactions have been studied less frequently. Here, we focus on the interaction between nutrition, performance, and the immune system in a specialist herbivorous insect, Manduca sexta. We used a conceptual framework in nutritional ecology (the geometric framework) to examine how changes in diet quality affect aspects of the immune system used for defense against parasitoids. We raised caterpillars throughout their entire larval development on five different experimental diets that varied in protein and carbohydrate content and measured five aspects of the immune system: encapsulation, phenoloxidase activity, prophenoloxidase activity, total hemolymph protein, and hemocyte density. Overall, different parts of the immune function varied in response to interactions between carbohydrates, protein, and intake, but protein reductions had the largest impacts-mostly detrimental. In addition, our data suggest that diet quality mediates the relationship between performance (growth and survival) and immune function, as well as trade-offs among different components of immune function. Our work is the first to examine the interplay between nutrition, performance, and immune function with the geometric framework in a specialist insect herbivore.

Dosage and frequency effects of the microalgae Dunaliella sp. on the diet of Litopenaeus vannamei challenged with Vibrio parahaemolyticus.

Carotenoid sources in shrimp diets have shown to be effective for improving survival, growth, reproductive capacity, stress resistance, and also for diminishing disease. Dunaliella sp. is known to have high levels of ß-carotenes, which works as pro-vitamin A, enhancing the immune response in shrimp. However, the administration of Dunaliella sp. in shrimp diet needs to be evaluated to determine the appropriate dose and frequency of administration needed to optimize performance in cultured white shrimp. Diets with three different concentrations of Dunaliella sp. flour (1.5, 2 and 3%) were tested, and each one was administered at three different time frequencies: daily, and at 3- and 7-days intervals. Shrimp fed for 20 days were then infected with Vibrio parahaemolyticus (1 × 106 CFU/mL). Hemolymph parameters including protein, glucose, lactate, cholesterol and triglycerides were analyzed to evaluate shrimp stress status. Additionally, L. vannamei innate non-specific immune response was examined by evaluating the activity of prophenoloxidase (proPO), phenoloxidase (PO) and superoxide dismutase (SOD) in hemolymph; shrimp survival was also recorded. Survival after infection with V. parahaemolyticus was higher for shrimp fed with diets consisting of 2% Dunaliella sp. administered every 3 and 7 days. Shrimp fed a diet consisting of 2% or 3% Dunaliella sp. administered every third day showed positive physiological and immune responses to infection. A decrease in lipid oxidation in plasma triglycerides was observed at 48 h post inoculation in shrimp fed at all diets regimes due to Dunaliella sp. antioxidant action. Experimental results suggest the importance of Dunaliella sp. dosage and feeding frequency in L. vannamei diet to improve the survival and immune response.

A myeloperoxidase precursor, pro-myeloperoxidase, is present in human plasma and elevated in cardiovascular disease patients.

Myeloperoxidase (MPO)-derived oxidants have emerged as a key contributor to tissue damage in inflammatory conditions such as cardiovascular disease. Pro-myeloperoxidase (pro-MPO), an enzymatically active precursor of myeloperoxidase (MPO), is known to be secreted from cultured bone marrow and promyelocytic leukemia cells, but evidence for the presence of pro-MPO in circulation is lacking. In the present study, we used a LC-MS/MS in addition to immunoblot analyses to show that pro-MPO is present in human blood plasma. Furthermore, we found that pro-MPO was more frequently detected in plasma from patients with myocardial infarction compared to plasma from control donors. Our study suggests that in addition to mature MPO, circulating pro-MPO may cause oxidative modifications of proteins thereby contributing to cardiovascular disease.

Suppression of active, but not total MMP-3, is associated with treatment response in a phase III clinical study of rheumatoid arthritis.

OBJECTIVE: Biologics for rheumatoid arthritis (RA) patients with moderate to severe disease may preserve joint function. Matrix metalloproteinase 3 (MMP-3), a key tissue degrading protease, is highly elevated in RA. MMP-3, which measures the total pool of circulating MMP-3 species (cMMP3), is a commonly measured biomarker in rheumatology. The aim was to investigate the association of activated MMP-3 (actMMP3) species with treatment response compared to cMMP-3. METHODS: The LITHE biomarker study (n=741) was a 1-year phase III, double-blind, placebo-controlled, parallel group study of TCZ in RA patients on stable methotrexate. cMMP-3 and actMMP-3 were assessed in fasting serum at baseline, week 4, 16, 24 and 52. Patients not achieving ACR20 remission at week 16 or 28 received rescue treatment (escapers). Spearman's correlation was analysed between biomarker baseline level or biomarker delta and clinical measures. Changes in biomarker levels were studied as a function of time and treatment. RESULTS: ActMMP-3 16-week change in treatment groups was predictive of 1-year radiographic progression; a small change in actMMP3 was equal to worsening radiographics. Baseline cMMP-3 was associated with 52-weeks' radiographic status and cMMP3 16-weeks' change was predictive of 1-year change in disease activity. ActMMP-3 was dose-dependently decreased by TCZ, and escapers decreased in actMMP-3 upon treatment. CONCLUSIONS: ActMMP-3 and cMMP-3 were found to be efficacy biomarkers of TCZ and actMMP-3 were able to differentiated doses. Moreover, the suppression of actMMP3, but not cMMP3 was associated with treatment response. This study illustrates that two biomarkers of the same protein may have different predictive capacities.

Concomitant elevations of MMP-9, NGAL, proMMP-9/NGAL and neutrophil elastase in serum of smokers with chronic obstructive pulmonary disease.

A growing body of evidence points towards smoking-related phenotypic differences in chronic obstructive pulmonary disease (COPD). As COPD is associated with systemic inflammation, we determined whether smoking status is related to serum levels of matrix metalloproteinase-9 (pro- and active MMP-9), neutrophil gelatinase-associated lipocalin (NGAL) and the proMMP-9/NGAL complex in patients with COPD. Serum samples were collected in 100 stable-phase COPD patients (82 smokers, 18 never-smokers) and 28 healthy adults (21 smokers, 7 never-smokers). Serum levels of studied factors were measured in ELISA. Our data provide the first evidence of simultaneously elevated serum levels of MMP-9, NGAL and proMMP-9/NGAL in COPD smokers. While the triad discriminated between smokers and non-smokers in the COPD group, MMP-9 and proMMP-9/NGAL (but not NGAL) discriminated between smokers with and without COPD. Adjustment for age and smoking pack-years did not alter the findings. Serum MMP-9, NGAL and proMMP-9/NGAL levels were not correlated with the GOLD stage or FEV1 decline. Furthermore, serum levels of neutrophil elastase (NE) and MMP-3 (but not of IL-6 and MMP-12) were also higher in COPD smokers than in healthy smokers before and after adjustment for age and pack-years. Among COPD smokers, levels of MMP-9, NGAL and proMMP-9/NGAL were positively correlated with NE (P < 0.0001) but not with the remaining factors. Gelatin zymography detected proMMP-9 in serum samples of healthy and COPD smoking groups. Our results suggest that associated serum levels of proMMP-9, NGAL, proMMP-9/NGAL and NE may reflect the state of systemic inflammation in COPD related to cigarette smoking.

Stability of Syk protein and mRNA in human peripheral blood basophils.

In human basophils, Syk expression is 10-fold lower than most other types of leukocytes. There are indirect studies that suggest that Syk protein is highly unstable (a calculated half-life less than 15 min) in human peripheral blood basophils. Therefore, in these studies, Syk stability was directly examined. Purified basophils were metabolically labeled and a pulse-chase experimental design showed Syk protein to be stable in the time frame of 12 h (95% likelihood that half-life is more than 12 h). However, its synthetic rate was very slow (∼10-fold slower) compared with CD34-derived basophils, which have been shown to express levels of Syk consistent with other mature circulating leukocytes. Syk mRNA expression was found to be 5-30-fold lower than other cell types (CD34-derived basophils, peripheral blood eosinophils, and plasmacytoid dendritic cells). Syk protein and mRNA levels, across cell types, were relatively concordant. Syk mRNA in basophils showed a half-life of 3.5 h, which was greater than that of interleukin-4 or Fc epsilon receptor I-α mRNA (∼2 h), but somewhat shorter than Fc epsilon receptor I-ß mRNA (8 h). A comparison of miR expression between CD34-derived and peripheral blood basophils demonstrated only 1 significant increase, in miR-150 (77-fold). Transfection in human embryonic kidney cells of a stabilized form of miR-150 showed that it modified expression of c-Myb mRNA but not of Syk mRNA or protein. These results suggest that low Syk expression in basophils results, not from protein instability and perhaps not from mRNA stability. Instead, the results point to the transcriptional nature of an important point of regulation.

Diagnostic Efficiency of Serum and Urine Procathepsin B and Cathepsin B in Patients with Carcinoma of the Urinary Bladder.

BACKGROUND: The aim of the study was to evaluate the diagnostic efficiency of cathepsins B (cathepsin B and procathepsin B) in patients with transient cell carcinoma of the urinary bladder. METHODS: Serum and urine concentrations of cathepsin B and procathepsin B were measured by two commercially available enzymatic immunoassays in a group of 125 patients with bladder cell carcinoma without metastases and in a group of 72 healthy individuals. Concentrations in urine were adjusted to creatinine. RESULTS: Concentrations of both cathepsin B and procathepsin B in serum and urine were significantly elevated in patients with bladder cell carcinoma (p < 0.0001 for U-procathepsin B, U-procathepsin B/creatinine, and U-cathepsin B/creatinine, p = 0.0001 for U-cathepsin B, p = 0.0002 for S-procathepsin B and p = 0.02 for S-cathepsin B). Comparison of all diagnostic efficiencies of cathepsin B and procathepsin B in serum and in urine showed the best diagnostic accuracy for procathepsin B in urine (AUC = 0.81 vs. 0.50). The ratio of U-procathepsin B/creatinine was also more efficient than the ratio of U-cathepsin B/creatinine (AUC = 0.81 vs. AUC = 0.70). The diagnostic efficiencies of both parameters in serum were low (S-procathepsin B: AUC = 0.50, S-cathepsin B: AUC = 0.60). U-procathepsin B and U-procathepsin B/creatinine ratio show significantly better diagnostic efficiency in patients with invasive bladder tumors than other parameters (S-procathepsin B, S-cathepsin B, U-cathepsin B and U-Cathepsin B/creatinine; U-procathepsin B: AUC = 0.82, U-procathepsin B/creatinine: AUC = 0.86, S-procathepsin B and cathepsin B: AUC = 0.51 - 0.68). CONCLUSIONS: Procathepsin B concentration in urine is a valuable diagnostic marker in patients with bladder cell carcinoma.

[Pro-prostate-specific antigen and its related indexes in the diagnosis of prostate cancer].

Pro-prostate-specific antigen (proPSA) is the precursor of PSA and a form of free PSA (fPSA). In recent years, a lot of studies have been done on proPSA, the roles of its related indexes in the diagnosis of prostate cancer, and the value of its clinical application. The correlated indexes of proPSA include proPSA, % pPSA, p2PSA, % p2PSA and prostate health index (PHI). They are more effective than total PSA (tPSA) and fPSA in the diagnosis of prostate cancer, especially % p2PSA and PHI, which may significantly increase our ability to detect and identify PCa and lower the rate of unnecessary biopsies. This article presents an overview on the advances in the studies of proPSA and the application of its related indexes in the diagnosis of prostate cancer.

Estimation of pro-renin as a prognostic marker for renal function in PUV patients.

OBJECTIVE: To estimate serum pro-renin, and its clinical significance, as a marker of chronic renal disease in posterior urethral valve (PUV) patients. PATIENTS AND METHODS: Forty patients with a PUV that were admitted to the hospital between 2010 and 2012 were reviewed. Twenty age-matched patients who were admitted for other non-urological diseases were selected for control. Clinical parameters, serum creatinine, urea, eGFR (estimated glomerular filtration rate) and serum pro-renin were analysed before and after valve ablation. RESULTS: Forty patients with PUV were included in the study. Three groups were formed according to age: <1 year, 1-3 years, >3 years. Pro-renin was measured using an ELISA (enzyme linked immunosorbent assay) kit and 'Graph Pad Prism' Software. The Spearman's rho test was used for correlation. Serum pro-renin had a negative correlation with the age group (correlation coefficient -0.395, P-value 0.012), eGFR (correlation coefficient -0.850, P-value<0.001) and follow-up eGFR (correlation coefficient -0.471, P-value 0.002). The pro-renin level correlated positively with serum creatinine at presentation (correlation coefficient 0.671, P-value<0.001), blood urea at initial presentation (correlation coefficient 0.684, P-value<0.001), serum creatinine at follow-up (correlation coefficient 0.546, P-value<0.001) and blood urea at follow-up (correlation 0.603, P-value<0.001). CONCLUSION: Pro-renin measured before PUV repair is associated with renal function three months after surgery.

Methodologic issues in the measurement of urinary renin.

BACKGROUND AND OBJECTIVES: Alge et al. recently reported that urinary renin may be a prognostic biomarker for AKI after cardiac surgery. However, their urinary renin levels far exceeded published plasma renin levels, whereas normally, urinary renin is <10% of plasma renin. This result raises questions about the specificity of the new Quantikine Renin ELISA Kit used in the work by Alge et al., which is claimed to detect total renin (i.e., renin and prorenin). Therefore, this study tested this assay. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Plasma and urine from 30 patients with hypertension, diabetes, or preeclampsia and 10 healthy pregnant women (randomly selected from sample sets obtained earlier to investigate urinary renin-angiotensin system components) were used to compare the ELISA with a validated renin immunoradiometric assay and an in-house enzyme kinetic assay. Measurements were performed before and after in vitro prorenin activation, representing renin and total renin, respectively. RESULTS: Total renin measurements by ELISA, immunoradiometric assay, and enzyme kinetic assay were highly correlated. However, ELISA results were consistently ≥10-fold higher. The ELISA standard yielded low to undetectable levels in the immunoradiometric assay and enzyme kinetic assay, except after prorenin activation, when the results were ≥10-fold lower than the ELISA results. In plasma, prorenin activation increased ELISA results by 10%-15%. Urine contained no detectable prorenin. CONCLUSIONS: The ELISA renin kit standard is prorenin, and its immunoreactivity and enzymatic activity after conversion to renin do not match the International Reference Preparation of human renin that has been used to validate previous immunoradiometric assays and enzyme kinetic assays; in fact, they are at least 10-fold lower, and thus, any measurements obtained with this ELISA kit yield levels that are at least 10-fold too high. The ELISA antibodies detect both renin and prorenin, with a preference for the former. Given these inconsistencies, urinary renin levels should be measured by established renin assays.

Proteomic profiling of N-linked glycoproteins identifies ConA-binding procathepsin D as a novel serum biomarker for hepatocellular carcinoma.

The aim of this study was to identify novel biomarkers for the diagnosis of, and potential therapeutic targets for, hepatocellular carcinoma (HCC). Multilectin affinity chromatography was used to enrich N-linked glycoproteins from nontumorous liver and HCC tissues followed by 2DE and protein identification by MS. Twenty-eight differentially expressed proteins were identified. Western blotting validated consistently lower concentrations of human liver carboxylesterase 1 and haptoglobin, and higher concentration of procathepsin D (pCD) in HCC tissues. Knockdown of cathepsin D (CD) expression mediated by siRNA significantly inhibited the in vitro invasion of two HCC cell lines, SNU449 and SNU473, which normally secrete high-levels of CD. Prefractionation using individual lectins demonstrated an elevation in ConA-binding glycoforms of proCD and CD in HCC tissues. In the serum of HCC patients, "ConA-binding proCD" (ConA-pCD) is significantly increased in concentration and this increase is comprised of several distinct upregulated acidic isoforms (pI 4.5-5.5). Receiver operating characteristic analysis showed that the sensitivity and specificity of serum ConA-pCD for HCC diagnosis were 85% and 80%, respectively. This is the first report that serum ConA-pCD is increased significantly in HCC and is potentially useful as a serological biomarker for diagnosis of HCC.

Association between serum levels of pro-metalloproteinase 1, tissue inhibitor of metalloproteinases 1 and 2 and prevalent cardiovascular disease in a population-based study.

AIM: The aim of the study was to test the association between circulating levels of matrix prometalloproteinase1 (pro-MMP1) and its tissue inhibitors TIMP1 and TIMP2 with prevalent cardiovascular events. METHODS: Prevalent cardiovascular events were documented in 500 participants of the Cyprus study (46% men) over the age of 40. Serum levels of pro-MMP1, TIMP1 and TIMP2 were measured with ELISA and the association between quartiles of serum levels and presence of cardiovascular disease (CVD) was tested using multivariable binary regression models. RESULTS: Lower serum levels of pro-MMP1 and TIMP1 were strongly associated with presence of CVD at baseline even after adjustment for conventional risk factors (P(for trend)=0.006 and P=0.001, respectively) and inflammatory factors (P(for trend)=0.005 and P=0.002, respectively) with people in the highest quartile of pro-MMP1 having a reduced odds for cardiovascular disease by about 70% compared to the lowest quartile (OR(adjusted)=0.26; 95% CI=0.19 to 0.75; P=0.01), whereas people with TIMP1 levels >1000 ng/mL had a 75% reduced odds for CVD compared to the rest (OR(adjusted)=0.25; 95% CI=0.11 to 0.60; P(for trend)=0.002). TIMP2 levels were not associated with prevalent cardiovascular disease. CONCLUSION: A strong association between lower levels of circulating pro-MMP1 and TIMP1 and risk of prevalent cardiovascular disease in a general population cohort over 40 years is evident, independent from common cardiovascular and inflammatory risk factors. The role of MMP1 and its tissue inhibitors, should be tested further in prospective studies of cardiovascular disease.

Evaluation of serum procathepsin B, cystatin B and cystatin C as possible biomarkers of ovarian cancer.

OBJECTIVES: To evaluate procathepsin B, as well as endogenous inhibitors of cysteine proteases (cystatin B and cystatin C) in biological fluids as possible biomarkers of ovarian cancer. To observe levels of serum procathepsin B in different age groups. STUDY DESIGN: The sample (N=27) of women with gynaecological tumours included 18 patients with ovarian cancer (n=18) and 9 patients with benign ovarian tumours (n=9); 72 healthy women were in the control group. All patients were treated in Novosibirsk Regional Oncological Center, Russia. Serum samples of healthy women (n=40) aged 18-70 years were used as controls for common biomarker of ovarian cancer CA-125. In the Procathepsin B study, serum samples of healthy women (n=32) aged 18-40 years (n=14), 41-55 years (n=10) and 56-80 (n=8) years were used as controls. METHODS: Common biomarker of ovarian cancer, CA-125, was assayed by using a commercial kit (Vector, Koltsovo, Novosibirsk Region, Russia). Procathepsin B was measured by means of a commercial kit for human procathepsin B (R&D, USA); cystatin C was measured by commercial ELISA kits for human (BioVendor, Czechia); cystatin B was measured by ELISA kits for human (USCN Life Science Inc., Wuhan, China). Statistical analysis was performed by one-way ANOVA (Statistica 10 Program). RESULTS: In the control group, serum procathepsin B concentration did not reveal age dependency. In the ovarian cancer group, both levels of serum procathepsin B and standard biomarker CA-125 increased significantly (both p<0.001) compared with the control group. In the benign ovarian tumour group, serum procathepsin B (p<0.001) and CA-125 (p=0.004) increased about 2.5- and 8-fold compared to the control group. Serum cystatin B level increased up to 1.7-fold in the ovarian cancer group compared to the control group. The increase of serum CA-125 was about 3.5-fold higher (p=0.017) and procathepsin B was 1.8-fold higher (p<0.05) in the ovarian cancer group compared to the benign tumour group. Cystatin B in ascites fluid increased equally in both ovarian cancer (p<0.001) and benign ovarian tumours group (p<0.05). Cystatin C concentration in ascites fluid increased only in patients with ovarian cancer (p<0.05) and did not change in the benign tumours group. Large increases of procathepsin B level (about 13-fold, p<0.001) and to a lesser degree of cystatin C (1.8-fold, p<0.05) and cystatin B levels (1.4 fold, p<0.001) were revealed in ascites fluids of patients with ovarian cancer compared to the control serum. The significant difference in serum procathepsin B levels was noted between the ovarian cancer and benign tumour groups (p<0.05), which could be used in differential diagnostics between malignant and benign gynaecological tumours. CONCLUSION: Serum procathepsin B demonstrated significant promise as a new biomarker of ovarian cancer.

A key role for the urokinase plasminogen activator (uPA) in invasive Group A streptococcal infection.

Recruitment of the serine protease plasmin is central to the pathogenesis of many bacterial species, including Group A streptococcus (GAS), a leading cause of morbidity and mortality globally. A key process in invasive GAS disease is the ability to accumulate plasmin at the cell surface, however the role of host activators of plasminogen in this process is poorly understood. Here, we demonstrate for the first time that the urokinase-type plasminogen activator (uPA) contributes to plasmin recruitment and subsequent invasive disease initiation in vivo. In the absence of a source of host plasminogen activators, streptokinase (Ska) was required to facilitate cell surface plasmin acquisition by GAS. However, in the absence of Ska, host activators were sufficient to promote cell surface plasmin acquisition by GAS strain 5448 during incubation with plasminogen or human plasma. Furthermore, GAS were able mediate a significant increase in the activation of zymogen pro-uPA in human plasma. In order to assess the contribution of uPA to invasive GAS disease, a previously undescribed transgenic mouse model of infection was employed. Both C57/black 6J, and AlbPLG1 mice expressing the human plasminogen transgene, were significantly more susceptible to invasive GAS disease than uPA-/- mice. The observed decrease in virulence in uPA-/-mice was found to correlate directly with a decrease in bacterial dissemination and reduced cell surface plasmin accumulation by GAS. These findings have significant implications for our understanding of GAS pathogenesis, and research aimed at therapeutic targeting of plasminogen activation in invasive bacterial infections.

Association of [-2]proPSA with biopsy reclassification during active surveillance for prostate cancer.

PURPOSE: Previous studies have suggested an association between [-2]proPSA expression and prostate cancer detection. Less is known about the usefulness of this marker in following patients with prostate cancer on active surveillance. Thus, we examined the relationship between [-2]proPSA and biopsy results in men enrolled in an active surveillance program. MATERIALS AND METHODS: In 167 men from our institutional active surveillance program we used Cox proportional hazards models to examine the relationship between [-2]proPSA and annual surveillance biopsy results. The outcome of interest was biopsy reclassification (Gleason score 7 or greater, more than 2 positive biopsy cores or more than 50% involvement of any core with cancer). We also examined the association of biopsy results with total prostate specific antigen, %fPSA, [-2]proPSA/%fPSA and the Beckman Coulter Prostate Health Index phi ([-2]proPSA/free prostate specific antigen) × (total prostate specific antigen)(½)). RESULTS: While on active surveillance (median time from diagnosis 4.3 years), 63 (37.7%) men demonstrated biopsy reclassification based on the previously mentioned criteria, including 28 (16.7%) of whom had reclassification based on Gleason score upgrading (Gleason score 7 or greater). Baseline and longitudinal %fPSA, %[-2]proPSA, [-2]proPSA/%fPSA and phi measurements were significantly associated with biopsy reclassification, and %[-2]proPSA and phi provided the greatest predictive accuracy for high grade cancer. CONCLUSIONS: In men on active surveillance, measures based on [-2]proPSA such as phi appear to provide improved prediction of biopsy reclassification during followup. Additional validation is warranted to determine whether clinically useful thresholds can be defined, and to better characterize the role of %[-2]proPSA and phi in conjunction with other markers in monitoring patients enrolled in active surveillance.

Serum index test %[-2]proPSA and Prostate Health Index are more accurate than prostate specific antigen and %fPSA in predicting a positive repeat prostate biopsy.

PURPOSE: We tested the hypothesis that serum isoform [-2]proPSA derivatives %p2PSA and Prostate Health Index are accurate predictors of prostate cancer in men scheduled for repeat biopsy. MATERIALS AND METHODS: The study was an observational prospective evaluation of a clinical cohort of men with 1 or 2 previous negative prostate biopsies, with persistent suspicion of prostate cancer. They were enrolled in the study to determine the diagnostic accuracy of %p2PSA using the formula, (p2PSA pg/ml)/(free prostate specific antigen ng/ml × 1,000)]× 100, and Beckman-Coulter Prostate Health Index using the formula, (p2PSA/free prostate specific antigen) × âˆštotal prostate specific antigen), and to compare it with the accuracy of established prostate cancer serum tests (total prostate specific antigen, free prostate specific antigen and percent free prostate specific antigen). Multivariable logistic regression models were complemented by predictive accuracy analysis and decision curve analysis. RESULTS: Prostate cancer was found in 71 of 222 (31.9%) subjects. %p2PSA and Prostate Health Index were the most accurate predictors of disease. %p2PSA significantly outperformed total prostate specific antigen, free prostate specific antigen, percent free prostate specific antigen and p2PSA in the prediction of prostate cancer (p ≤0.01), but not Prostate Health Index (p = 0.094). Prostate Health Index significantly outperformed total prostate specific antigen and p2PSA (p ≤0.001) but not free prostate specific antigen (p = 0.109) and free/total prostate specific antigen (p = 0.136). In multivariable logistic regression models %p2PSA and Prostate Health Index achieved independent predictor status, and significantly increased the accuracy of multivariable models including prostate specific antigen and prostate volume with or without percent free prostate specific antigen and prostate specific antigen density by 8% to 11% (p ≤0.034). At a %p2PSA cutoff of 1.23, 153 (68.9%) biopsies could have been avoided, missing prostate cancer in 6 patients. At a Prostate Health Index cutoff of 28.8, 116 (52.25%) biopsies could have been avoided, missing prostate cancer in 6 patients. CONCLUSIONS: Serum %p2PSA and Prostate Health Index are more accurate than standard reference tests in predicting repeat prostate biopsy outcome, and could avoid unnecessary repeat biopsies.