Early Selective C-Reactive Protein Apheresis in a Patient with Acute ST Segment Elevation Myocardial Reinfarction.

The patient was admitted for urgent coronary angiography following an acute anterior ST segment elevation myocardial reinfarction (STEMI) caused by acute stent thrombosis. A stent had been implanted 10 days prior to the reinfarction for an acute anterior STEMI. However, the patient had stopped taking ticagrelor post-discharge. Primary percutaneous coronary intervention of the left anterior descending artery was performed. Subsequently, due to a high C-reactive protein (CRP) level, 3 CRP apheresis sessions were performed, with the first session starting 12 h after the onset of symptoms. A significant drop in CRP was noted after each apheresis. The post-procedural course was uneventful.

GATA2 mutation underlies hemophagocytic lymphohistiocytosis in an adult with primary cytomegalovirus infection.

We report a case of a 27-year old woman with persistent fever and pancytopenia who had multiple episodes of a hemophagocytic lymphohistiocytosis (HLH) like condition. The criterion for HLH was satisfied; primary cytomegalovirus (CMV) infection was identified as the cause. Further examination revealed a GATA binding protein 2 mutation. Reports of GATAs deficiency presenting with HLH after primary CMV infection is very limited. As early recognition and diagnosis will improve patients' outcomes, internists and infectious disease specialists should be aware of this disease.

Label-Free Specific Detection and Collection of C-Reactive Protein Using Zwitterionic Phosphorylcholine-Polymer-Protected Magnetic Nanoparticles.

In this study, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)]-protected Fe3O4 nanoparticles were prepared and used for the label-free specific detection and collection of an acute inflammation marker, C-reactive protein (CRP), in a simulated body fluid. The Fe3O4 nanoparticle surface was modified using poly(MPC) by surface-initiated atom-transfer radical polymerization. The density of poly(MPC) was 0.16 chains/nm2, and the colloidal stability of the nanoparticles in aqueous media and human plasma was effectively improved by surface modification. The size of the as-prepared poly(MPC)-protected Fe3O4 nanoparticles was ∼200 nm. After coming into contact with CRP, the nanoparticles aggregated as CRP comprises five subunits, and each subunit can bind to a phosphorylcholine group with two free Ca2+ ions. The change in the nanoparticle size exhibited a good correlation with the CRP concentration in the range of 0-600 nM. A low limit of detection of 10 nM for CRP was observed. The particles effectively reduced the adsorption of nonspecific proteins, and the change in the nanoparticle size with CRP was not affected by the coexistence of bovine serum albumin at a concentration 1000 times greater than that of CRP. Nanoparticle aggregates formed using CRP were dissociated using ethylenediamine- N, N, N', N'-tetraacetic acid, disodium salt, thereby regenerating poly(MPC)-protected Fe3O4 nanoparticles. In addition, CRP was collected from aqueous media using an acidic buffer solution and human plasma. CRP-containing aqueous solutions were treated with poly(MPC)-protected Fe3O4. After poly(MPC)-protected Fe3O4 nanoparticles were separated using a neodymium magnet and centrifugation, the concentration of CRP in the media dramatically decreased. In stark contrast, the concentration of albumin present in the test solution did not change even after treatment with the nanoparticles. Therefore, nanoparticles specifically recognize CRP from complex biological fluids. Although inhibition tests in the presence of 1,2-dioleoyl- sn-glycero-3-phosphocholine liposomes or free poly(MPC) were also carried out, the binding of poly(MPC)-protected Fe3O4 to CRP was not affected by these inhibitors. In conclusion, poly(MPC)-brush-bearing magnetic nanoparticles can serve not only as reliable materials for detecting and controlling the levels of CRP in simulated body fluids but also as diagnostic and therapeutic materials.

Development of A Lateral Flow Highway: Ultra-Rapid Multitracking Immunosensor for Cardiac Markers.

The integration of several controlled parameters within a single test system is experiencing increased demand. However, multiplexed test systems typically require complex manufacturing. Here, we describe a multiplexed immunochromatographic assay that incorporates a conventional nitrocellulose membrane, which is used together with microspot printing, to construct adjacent microfluidic "tracks" for multiplexed detection. The 1 mm distance between tracks allows for the detection of up to four different analytes. The following reagents are applied in separate zones: (a) gold nanoparticle conjugates with antibodies against each analyte, (b) other antibodies against each analyte, and (c) antispecies antibodies. The immersion of the test strip in the sample initiates the lateral flow, during which reagents of different specificities move along their tracks without track erosion or reagent mixing. An essential advantage of the proposed assay is its extreme rapidity (1-1.5 min compared with 10 min for common test strips). This assay format was applied to the detection of cardiac and inflammatory markers (myoglobin, D-dimer, and C-reactive protein) in human blood, and was characterized by high reproducibility (8%-15% coefficient of variation) with stored working ranges of conventional tests. The universal character of the proposed approach will facilitate its use for various analytes.

A Multi-Region Magnetoimpedance-Based Bio-Analytical System for Ultrasensitive Simultaneous Determination of Cardiac Biomarkers Myoglobin and C-Reactive Protein.

Cardiac biomarkers (CBs) are substances that appear in the blood when the heart is damaged or stressed. Measurements of the level of CBs can be used in course of diagnostics or monitoring the state of the health of group risk persons. A multi-region bio-analytical system (MRBAS) based on magnetoimpedance (MI) changes was proposed for ultrasensitive simultaneous detection of CBs myoglobin (Mb) and C-reactive protein (CRP). The microfluidic device was designed and developed using standard microfabrication techniques for their usage in different regions, which were pre-modified with specific antibody for specified detection. Mb and CRP antigens labels attached to commercial Dynabeads with selected concentrations were trapped in different detection regions. The MI response of the triple sensitive element was carefully evaluated in initial state and in the presence of biomarkers. The results showed that the MI-based bio-sensing system had high selectivity and sensitivity for detection of CBs. Compared with the control region, ultrasensitive detections of CRP and Mb were accomplished with the detection limits of 1.0 pg/mL and 0.1 pg/mL, respectively. The linear detection range contained low concentration detection area and high concentration detection area, which were 1 pg/mL⁻10 ng/mL, 10⁻100 ng/mL for CRP, and 0.1 pg/mL⁻1 ng/mL, 1 n/mL⁻80 ng/mL for Mb. The measurement technique presented here provides a new methodology for multi-target biomolecules rapid testing.

Therapeutic plasma exchange versus double plasma molecular absorption system in hepatitis B virus-infected acute-on-chronic liver failure treated by entercavir: A prospective study.

BACKGROUND: Therapeutic plasma exchange (TPE) and double plasma molecular absorption system (DPMAS) were two extracorporeal liver support systems. Few studies compared their efficacy profile. OBJECTIVE: This study was to compare the efficacy of TPE and DPMAS on acute-on-chronic liver failure (ACLF) caused by hepatitis B virus (HBV-ACLF). METHODS: 60 HBV-ACLF patients were enrolled and prospectively studied. All patients received entecavir therapy, and were assigned to TPE group (n = 33) and DPMAS group (n = 27). Primary end-points were the effects of TPE and DPMAS on liver function and serum inflammatory markers. RESULTS: Serum procalcitonin, interleukin (IL)-6, and high sensitive C-reactive protein (hsCRP) were significantly elevated in patients with HBV-ACLF. TPE achieved significantly higher removal rates of total bilirubin (TBIL, P = .002), direct bilirubin (DBIL, P = .006), and hsCRP (P = .010) than DPMAS, but DPMAS displayed lower loss rate of albumin (P = .000). TPE and DPMAS resulted in similarly increased serum IL-6 levels and comparable 12-week survivals (P > .05). Multivariate analysis showed that hospital stay (Relative Risk [RR]: 1.062, 95% Confidence Interval [CI]: 1.011-1.115, P = .016), prothrombin time (RR: 1.346, 95% CI: 1.077-1.726, P = .010), and international normalized ratio (RR: 0.013, 95% CI: 0.006-0.788, P = .041) were independent predictors for 12-week survival. Both TPE and DPMAS treatments were well-tolerated. CONCLUSION: Compared to DPMAS, TPE was more efficient in eliminating TBIL, DBIL, and hsCRP, but it was associated with higher loss rate of albumin. TPE and DPMAS were similar in improving 12-week survivals in HBV-ACLF.

HC-HA/PTX3 Purified From Amniotic Membrane Promotes BMP Signaling in Limbal Niche Cells to Maintain Quiescence of Limbal Epithelial Progenitor/Stem Cells.

To explore how limbal niche cells (LNCs) may control quiescence, self-renewal, and corneal epithelial lineage commitment/differentiation of limbal epithelial progenitor/stem cells (LEPCs), we have established an in vitro sphere assay by reunion between the two cell types in three-dimensional Matrigel. The resultant sphere exhibits inhibition of corneal epithelial lineage commitment/differentiation and marked clonal growth of LEPCs, of which the latter is correlated with activation of canonical Wnt signaling. Herein, we have created a similar reunion assay in immobilized heavy chain-hyaluronic acid/pentraxin 3 (HC-HA/PTX3), which is purified from amniotic membrane (AM) and consists of a complex formed by hyaluronic covalently linked to heavy chain 1 of inter-α-inhibitor and noncovalently linked to pentraxin 3. The resultant spheres exhibited similar suppression of corneal epithelial lineage commitment/differentiation but upregulation of quiescence markers including nuclear translocation of Bmi-1, and negligible clonal growth of LEPCs. This outcome was correlated with the suppression of canonical Wnt but activation of noncanonical (Planar cell polarity) Wnt signaling as well as BMP signaling in both LEPCs and LNCs. The activation of BMP signaling in LNCs was pivotal because nuclear translocation of pSmad1/5/8 was prohibited in hLEPCs when reunioned with mLNCs of conditionally deleted Bmpr1a;Acvr1(DCKO) mice. Furthermore, ablation of BMP signaling in LEPCs led to upregulation of cell cycle genes, downregulation of Bmi-1, nuclear exclusion of phosphorylated Bmi-1, and marked promotion of the clonal growth of LEPCs. Hence, HC-HA/PTX3 uniquely upregulates BMP signaling in LNCs which leads to BMP signaling in LEPCs to achieve quiescence, helping explain how AM transplantation is clinically useful to be used as a matrix for ex vivo expansion of LEPCs and to treat corneal blindness caused by limbal stem cells deficiency.

Infusion of pharmaceutical-grade natural human C-reactive protein is not proinflammatory in healthy adult human volunteers.

RATIONALE: Baseline circulating concentrations of C-reactive protein (CRP) are significantly associated with cardiovascular disease risk in general populations. This modest association has been inappropriately conflated with causality, and it has been claimed that CRP is proatherogenic. Most of the known causative factors for atherosclerosis stimulate increased CRP production, but comprehensive genetic epidemiology studies provide no support for a pathogenic role of CRP. The reported proinflammatory effects of human CRP preparations on healthy cells in vitro and in healthy animals in vivo have all been produced by poorly characterized CRP preparations, demonstrably caused by impurities, or elicited by CRP made in recombinant Escherichia coli not by humans. None of the in vitro or animal findings have been reproduced with pure natural human CRP. Nevertheless, the strong proinflammatory effects of infusing recombinant bacterial CRP into humans have still been inappropriately ascribed to CRP. OBJECTIVE: To investigate the effects of infusion into healthy adult human volunteers of pure natural human CRP. METHODS AND RESULTS: Comprehensively characterized, pharmaceutical-grade, endotoxin-free, purified CRP, prepared to GMP standard from pooled normal human donor plasma was infused as an intravenous bolus in 7 healthy adult human volunteers at ≤2 mg/kg to provide circulating CRP concentrations ≤44 mg/L. No recipient showed any significant clinical, hematologic, coagulation, or biochemical changes, or any increase in proinflammatory cytokines or acute phase proteins. CONCLUSIONS: The human CRP molecule itself is not proinflammatory in healthy human adults.

Antibacterial effect of porcine PTX3 against Streptococcus suis type 2 infection.

Pentraxin 3 (PTX3), a soluble pattern recognition receptor, plays an important role in innate immunity and has been implicated to be a candidate resistance gene against Streptococcus suis 2 infection. To discover the antibacterial effect of porcine PTX3 against S. suis 2, the 42-kDa PTX3 protein was expressed by Chinese hamster ovary cells (CHO), and an additional eukaryotic expression vector pVAX-ptx3 was constructed. The expressed porcine PTX3 mediated a range of antibacterial activities including increasing phagocytic capacity of primary porcine alveolar macrophages (PAM) against S. suis 2 and inhibiting adhesion of S. suis 2 to human epidermoid cancer cells (Hep-2). In mouse model, pre-intramuscular injecting with pVAX-ptx3 reduced mortality and reduced bacteria loads in blood, spleen, lung and brain compared with that of control group during 2-12 h following intraperitoneal injection (i.p.) with S. suis 2. Meanwhile, the expressions of IL-6 and IL-8 in blood were increased in pVAX-ptx3 group, whereas no obvious changes about IL-10. In piglet model, bacteria load in blood of pVAX-ptx3 group was significantly lower than that of control group after i.p. with S. suis 2, correspondingly, expression of IL-6 and IL-8 were significantly increased in pVAX-ptx3 group. In contrast, white blood cell (WBC) and neutrophil cell (NEU) count of peripheral blood in pVAX-ptx3 group were lower than that of control group. These studies described a novel antibacterial role for porcine PTX3 against S. suis 2 both in vitro and in vivo and suggested that porcine PTX3 may be a potential biological agent against S. suis 2 in pig and be used for the clinical prevention and treatment of streptococcosis caused by S. suis 2.

Selective apheresis of C-reactive protein: a new therapeutic option in myocardial infarction?

BACKGROUND: There is substantial evidence that C-reactive protein (CRP) mediates secondary damage of the myocardium after acute myocardial infarction (AMI). The aim of this animal trial in pigs was to specifically deplete CRP from porcine plasma after AMI and to study possible beneficial effects of the reduced CRP concentration on the infarcted area. METHODS: Ten pigs received balloon catheter-induced myocardial infarction. CRP was depleted from five animals utilizing a new specific CRP-adsorber, five animals served as controls. The area of infarction was analyzed by cardiovascular magnetic resonance imaging on day 1 and day 14 after AMI. Porcine CRP levels were determined by ELISA. RESULTS: CRP-apheresis resulted in a mean reduction of the CRP levels up to 48.3%. The area of infarction was significantly reduced by 30 ± 6% (P = 0.003) within 14 days in the treatment group, whereas it increased by 19 ± 11% (P = 0.260) in the controls. Fourteen days after infarction, the infarcted area revealed compact, transmural scars in the controls, whereas animals receiving CRP-apheresis showed spotted scar morphology. In the interventional group, a significantly higher left ventricular ejection fraction (LVEF) was observed after 14 days as compared to the controls (57.6 ± 2.4% vs. 46.4 ± 2.7%; P = 0.007). CONCLUSIONS: In a pig model for AMI, we observed that selective CRP-apheresis significantly reduces CRP levels and the volume of the infarction zone after AMI. Additionally, it changes the morphology of the scars and preserves cardiac output (LVEF).

[The clinical informativeness of detection of antibodies to citrullinated proteins under rheumatoid arthritis].

The main diagnostic laboratory markers of rheumatoid arthritis are IgM rheumatoid factor and antibodies to citrullinated proteins. The IgM rheumatoid factor is a sensitive but insufficiently specific marker of rheumatoid arthritis. The antibodies to citrullinated proteins have a higher specificity for diagnostic of rheumatoid arthritis. The antibodies to cyclic citrullinated peptide and modified citrullinated vimentin are the main representatives of family of antibodies to citrullinated proteins applying in clinical diagnostic practice. The study was carried out to deternine the role of antibodies to citrullinated proteins and modified citrullinated vimentin in diagnostic, evaluation of activity and severity of destructive alterations under rheumatoid arthritis. The samplings of 993 patients with reliable diagnosis of rheumatoid arthritis. 179 patients with other rheumatoid diseases and 30 healthy donors were examined. The measurement of serum concentration of IgM rheumatoid factor and C-reactive protein was implemented by immune nephelometric analysis and antibodies to citrullinated proteins were analyzed by enzymoimmunoassay The erythrocyte sedimentation rate was established using the Westergreen technique. It was established that antibodies to modified citrullinated vimentin had the highest diagnostic specificity (83%), antibodies to cyclic citrullinated peptide had the highest diagnostic specificity (87%). The diagnostic specificity of joint detection of IgM rheumatoid factor, antibodies to citrullinated proteins and antibodies to modified citrullinated vimentin made up to 87%. In patients negative to rheumatoid factor the rate ofdetection of antibodies to citrullinated proteins made up to 34% and antibodies to modified citrullinated vimentin made up to 48%. The diagnostic effectiveness of detection of antibodies to citrullinitted proteins (ratio of likelihood of positive and negative results of test was correspondingly 5.5 and 0.3; area under ROC curve 0.8) and antibodies to modified citrullinated vimentin (ratio of likelihood of positive and negative results of test was correspondingly 4.4 and 0.2; area under ROC curve 0.9) surpassed the same in analysis of IgM rheumatoid factor (ratio of likelihood of positive results--3.2, ratio of likelihood of negative results--0.4, area under ROC curve--0.8). The weak positive correlation relationship was established between concentration of antibodies to cyclic citrillinatedpeptide/antibodies to modified citrullinated vimentin in blood serum and indicators of clinical laboratory activity of rheumatoid arthritis (ESR, CRP DAS 28, (r-0.2. p < 0.05). The high positive levels of antibodies to modified citrullinated vimentin associated with expressed destructive affection of joints (p < 0.02). The antibodies to cyclic citrullinated peptide are the most highly specific and clinically informative laboratory diagnostic marker of rheumatoid arthritis. The detection of antibodies to modified citrullinated vimentin is an important additional serological test to diagnose rheumatoid arthritis in IgM rheumatoid factor-negative and/or antibodies to cyclic citrullinated peptide-negative patients and to forecast severe destructive affection of joints under the given disease. The joint study of IgM rheumatoid factor, antibodies to cyclic citrullinated peptide and antibodies to modified citrullinated vimentin under rheumatoid arthritis has higher diagnostic sensitivity as compared with isolated antibodies to citrullinated proteins.

The proteomic profile of circulating pentraxin 3 (PTX3) complex in sepsis demonstrates the interaction with azurocidin 1 and other components of neutrophil extracellular traps.

Pentraxin 3 (PTX3), a long pentraxin subfamily member in the pentraxin family, plays an important role in innate immunity as a soluble pattern recognition receptor. Plasma PTX3 is elevated in sepsis (~200 ng/ml) and correlates with mortality. The roles of PTX3 in sepsis, however, are not well understood. To investigate the ligands of PTX3 in sepsis, we performed a targeted proteomic study of circulating PTX3 complexes using magnetic bead-based immunopurification and shotgun proteomics for label-free relative quantitation via spectral counting. From septic patient fluids, we successfully identified 104 candidate proteins, including the known PTX3-interacting proteins involved in complement activation, pathogen opsonization, inflammation regulation, and extracellular matrix deposition. Notably, the proteomic profile additionally showed that PTX3 formed a complex with some of the components of neutrophil extracellular traps. Subsequent biochemical analyses revealed a direct interaction of bactericidal proteins azurocidin 1 (AZU1) and myeloperoxidase with PTX3. AZU1 exhibited high affinity binding (K(D) = 22 ± 7.6 nm) to full-length PTX3 in a calcium ion-dependent manner and bound specifically to an oligomer of the PTX3 N-terminal domain. Immunohistochemistry with a specific monoclonal antibody generated against AZU1 revealed a partial co-localization of AZU1 with PTX3 in neutrophil extracellular traps. The association of circulating PTX3 with components of the neutrophil extracellular traps in sepsis suggests a role for PTX3 in host defense and as a potential diagnostic target.

Developing column material for the separation of serum amyloid P and C reactive protein from biological sources.

In this study, we have investigated the isolation of serum amyloid P (SAP) and C-reactive protein (CRP) from rainbow trout. It has recently been found that SAP is deposited in atherosclerotic lesions or neurofibrillary tangles, which are related to aging process and Alzheimer's disease. Given the importance of CRP, the CRP level in blood is becoming recognized as a potential means of monitoring cardiovascular risk. These two proteins, members of the pentraxin family of oligomeric serum proteins, were isolated from rainbow trout using N-methacryloyl-phosphoserine (MA-pSer) immobilized poly (2-hydroxy ethylmethacrylate) (PHEMA) cryogels as a column material in a fast protein liquid chromatography system. The separation process was verified in two steps. First, SAP and CRP proteins were isolated together from serum sample of rainbow trout using MA-pSer/PHEMA cryogel columns. Second, SAP protein was separated chromatographically from CRP protein using the Ca(2+) ion immobilized PHEMA cryogel column. According to the data, a new and effective technique has been developed for the isolation of SAP and CRP proteins from a biological source, rainbow trout. Finally, purified SAP and CRP were loaded using sodium dodecyl sulfate-polyacrylamide gel and western blot analysis to investigate the purity of chromatographically isolated SAP and CRP compared with commertial SAP and CRP.

Anti-bacterial activity of Achatina CRP and its mechanism of action.

The physiological role of C-reactive protein (CRP), the classical acute-phase protein, is not well documented, despite many reports on biological effects of CRP in vitro and in model systems in vivo. It has been suggested that CRP protects mice against lethal toxicity of bacterial infections by implementing immunological responses. In Achatina fulica CRP is a constitutive multifunctional protein in haemolymph and considered responsible for their survival in the environment for millions of years. The efficacy of Achatina CRP (ACRP) was tested against both Salmonella typhimurium and Bacillus subtilis infections in mice where endogenous CRP level is negligible even after inflammatory stimulus. Further, growth curves of the bacteria revealed that ACRP (50 microg/mL) is bacteriostatic against gram negative salmonellae and bactericidal against gram positive bacilli. ACRP induced energy crises in bacterial cells, inhibited key carbohydrate metabolic enzymes such as phosphofructokinase in glycolysis, isocitrate dehydrogenase in TCA cycle, isocitrate lyase in glyoxylate cycle and fructose-1,6-bisphosphatase in gluconeogenesis. ACRP disturbed the homeostasis of cellular redox potential as well as reduced glutathione status, which is accompanied by an enhanced rate of lipid peroxidation. Annexin V-Cy3/CFDA dual staining clearly showed ACRP induced apoptosis-like death in bacterial cell population. Moreover, immunoblot analyses also indicated apoptosis-like death in ACRP treated bacterial cells, where activation of poly (ADP-ribose) polymerase-1 (PARP) and caspase-3 was noteworthy. It is concluded that metabolic impairment by ACRP in bacterial cells is primarily due to generation of reactive oxygen species and ACRP induced anti-bacterial effect is mediated by metabolic impairment leading to apoptosis-like death in bacterial cells.

[The evaluation of sensitivity and specificity of technique of detection of C-reactive protein under diagnostic of infectious complications in patients with acute lymphoblastic leucosis receiving chemotherapy].

The C-reactive protein is a generally recognized marker of inflammation and bacterial infection. However, issue of diagnostic effectiveness of this indicator is still open-ended in case of patients with oncologic hematological diseases. The level of C-reactive protein can increase under neoplastic processes. On the contrary, the inhibition of immune response observed under cytoplastic therapy can decrease synthesis of this protein. The study was organized to establish levels of C-reactive protein as markers of infection in adult patients with acute lymphoblastic leucosis under application of chemotherapy and to evaluate their diagnostic effectiveness. The sampling included 34 patients with acute lymphoblastic leucosis all patients had infectious complications at various stages of treatment. The levels of C-reactive protein in groups of patients with localized infections (mucositis, abscess, pneumonia, etc.) or fever of unknown genesis had no statistical differences but were reliably higher in patients without infectious complications. The concentrations of C-reactive protein in patients with syndrome of systemic inflammatory response and sepsis had no differences. At the same time, level of C-reactive protein under systemic infection (syndrome of systemic inflammatory response, sepsis) was reliably higher than in case of localized infection. The diagnostically reliable levels of C-reactive protein were established as follows: lower than 11 mg/l--infectious complications are lacking; higher than 11 mg/l--availability of infectious process; higher than 82 mg/l--generalization of infection. The given levels are characterized by high diagnostic sensitivity (92% and 97% correspondingly) and specificity (97% and 97%) when patients receive therapy without application of L-asparaginase. At the stages of introduction of this preparation effecting protein synthesizing function of liver sensitivity of proposed criteria are decreased (69% and 55% correspondingly). However; due to high specificity (100% and 96%) their diagnostic effectiveness remains high.

The phosphocholine-binding pocket on C-reactive protein is necessary for initial protection of mice against pneumococcal infection.

Human C-reactive protein (CRP) protects mice from lethal Streptococcus pneumoniae infection when injected into mice within the range of 6 h before to 2 h after the administration of pneumococci. Because CRP binds to phosphocholine-containing substances and subsequently activates the complement system, it has been proposed that the antipneumococcal function of CRP requires the binding of CRP to phosphocholine moieties present in pneumococcal cell wall C-polysaccharide. To test this proposal experimentally, in this study, we utilized a new CRP mutant incapable of binding to phosphocholine. Based on the structure of CRP-phosphocholine complexes, which showed that Phe(66), Thr(76), and Glu(81) formed the phosphocholine-binding pocket, we constructed a CRP mutant F66A/T76Y/E81A in which the pocket was blocked by substituting Tyr for Thr(76). When compared with wild-type CRP, mutant CRP bound more avidly to phosphoethanolamine and could be purified by affinity chromatography using phosphoethanolamine-conjugated Sepharose. Mutant CRP did not bind to phosphocholine, C-polysaccharide, or pneumococci. Mutant CRP was free in the mouse serum, and its rate of clearance in vivo was not faster than that of wild-type CRP. When either 25 µg or 150 µg of CRP was administered into mice, unlike wild-type CRP, mutant CRP did not protect mice from lethal pneumococcal infection. Mice injected with mutant CRP had higher mortality rates than mice that received wild-type CRP. Decreased survival was due to the increased bacteremia in mice treated with mutant CRP. We conclude that the phosphocholine-binding pocket on CRP is necessary for CRP-mediated initial protection of mice against lethal pneumococcal infection.

[The value of quantitative analysis of procalcitonine in diagnostics of septic complications in patients with autoimmune rheumatic diseases].

The infections very often complicate the course of autoimmune rheumatic diseases. In diagnostic of septic complications in rheumatic patients the new biomarkers of infections can have a decisive importance. The procalciotonine test is one of them. The issue was to evaluate the diagnostic informativity of this test. The sample included 93 patients. The examination was applied to 65 patients with rheumatic diseases. Among them, 13 patients had bacterial infections. The group consisted of 33 patients with rheumatoid arthritis, 11 patients with systemic lupus erythematous, 6 patients with systemic angiitis, and 15 patients with other rheumatic diseases. The comparative group included 27 patients of cardio-therapeutic profile and 8 of these patients had bacterial infections. The procalcitonine test was applied with quantitative electrochemiluminescent technique. In patients with rheumatoid arthritis the mean levels of procalciotonine test consisted 0.10 +/- 0.13 ng/ml; with systemic lupus erythematous--0.08 +/- 0.06 ng/ml; with systemic angiitis--0.22 +/- 0.2 ng/ml; with other rheumatic diseases--0.12 +/- 0.15 ng/ml; of cardio-therapeutic profile without infections--0.08 +/- 0.06 ng/vl/ With threshold of procalcitonine test higher than 0.5/ml the sensitivity to diagnostic of infections consisted of 58%, specificity--94% in the group with rheumatic diseases. The procalciotonine test in case of no infection process with values higher than 0.5 ng/ml was detected in three patients. The evaluation of dependence of sensitivity and specificity for procalciotonine test and C-reactive protein the area under curve of procalcitonine test was larger in patients with rheumatic diseases (0.85 against 0.79) and in patients of cardio-therapeutic profile (0.92 against 0.90). The quantitative procalcitonine test is the best technique to detect septic complications in rheumatic patients.

[The prognostic value of biochemical indicators under neonatal hepatitis of different etiology].

Recently, the share of children with verified neonatal hepatitis induced by genetic predisposition, malformations of biliary tracts, inborn infections with affection of hepatobiliary system increased. The comprehensive biochemical examination of 62 children aged from 1.5 months to 2 years old with diagnosis of neonatal hepatitis. The changes of standard indicators of cytolysis, cholestasis and protein metabolism were on average moderate in group with reliable increase of protein concentration of acute phase of inflammation. The peak changes of biochemical indicators during primary examination are revealed in group of children with malformations of hepatobiliary system conditioned by viruses of herpetic group and in the process of development of expressed fibrosis of liver up to first year of life. The detection of proteins of acute phase makes it possible to objectively evaluate the presence of prolonged inflammatory process in liver and to promote prognosis of course of neonatal hepatitis in children of early age and timely correction of therapy and improvement of outcomes of disease. The detection of C-reactive protein, alpha2-macroglobulin and alpha1-antitripsin is recommended to be included into algorithm of examination of children with neonatal hepatitis.

Chemical analysis of C-reactive protein synthesized by human aortic endothelial cells under oxidative stress.

C-reactive protein (CRP) is a clinical biomarker of inflammation, and high levels of CRP correlate with cardiovascular disease. The objectives of this study were to test our hypothesis that oxidized low-density lipoprotein (ox-LDL) induces the release of CRP from human aortic endothelial cells (HAECs) and to optimize several analytical methods to identify CRP released from cultured cells in a model of atherogenic stress. HAECs were incubated with copper-oxidized LDL, and the supernatant was subsequently purified by diethylaminoethyl chromatography and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). We identified an optimal buffer for the elution of CRP, which contained 0.05 M sodium phosphate and 2.0 M NaCl (pH 4.5). Purified CRP was digested with trypsin and subjected to high-performance LC with an optimal mobile phase of acetonitrile-water containing 0.1% formic acid (50:50, v/v) and an optimal mobile phase flow rate of 0.2 mL/min. We identified optimal parameters for MS/MS analysis of CRP, including sheath gas pressure (80 psi), capillary temperature (275 °C), collision energy (25%), tube lens offset (-5 V), auxiliary gas pressure (0 psi), and isolation width of parent ion (m/z value = 3). Characterization of CRP was based on the extracted ion chromatograms and selected multiple-reaction monitoring spectra of three peptides (peptide-1, -2, and -3) derived from trypsin-digested intact CRP standard. CRP peptide-2 and peptide-3 were identified in the supernatant of ox-LDL-treated HAECs. Confirmation of CRP was based on LC-MS/MS and enzyme-linked immunosorbent assay analysis of CRP in purified HAEC supernatant, as well as real-time PCR analysis of CRP mRNA levels in HAECs.

Expression and characterization of 15N-labeled human C-reactive protein in Escherichia coli and Pichia pastoris for use in isotope-dilution mass spectrometry.

Levels of C-reactive protein (CRP) in serum are correlated with inflammation and disease in humans. A higher level quantitative method, such as isotope-dilution mass spectrometry (ID-MS) is needed to compare and standardize the many commercial CRP assays. We compare the expression and purification of (15)N-CRP from Escherichia coli and Pichia pastoris and show that the protein isolated from P. pastoris has native pentameric structure along with high isotopic enrichment as shown by software developed specifically for this purpose. When this preparation was mixed in various ratios with unlabeled CRP and tryptic peptides of the mixtures were analyzed by LC-MS/MS, the ratios of heavy and light peaks were tightly correlated with input amounts of each protein. In this report we confirm the suitability of (15)N-rCRP as an internal standard in ID-MS. Standardization of CRP assays should help validate the relationship between CRP and human health.