Association of serum amyloid A and prognosis in people with diabetes and COVID-19: A retrospective cohort study.

AIMS/INTRODUCTION: Serum amyloid A (SAA) is an acute phase reactive protein that plays a vital role in the early diagnosis, risk prediction, efficacy observation and prognosis evaluation of infectious diseases. This study aimed to assess the association between SAA levels and the prognosis of patients with coronavirus disease 2019 (COVID-19) and diabetes. MATERIALS AND METHODS: We carried out this retrospective cohort study from March 2022 to May 2022. The population was stratified by tertiles of SAA levels: low (<8.5 mg/L), medium (8.5-36 mg/L) and high (>36 mg/L). The primary outcome was whether the patient developed severe COVID-19, and secondary outcomes included the need for invasive mechanical ventilation and length of hospital stay. Logistic regression analyses were carried out to identify risk factors affecting the prognosis of patients with COVID-19 and diabetes. RESULTS: We analyzed 910 diabetes patients with COVID-19. The median age of the patients was 69 years, and 52.3% were men. As SAA levels increased, the proportion of severe COVID-19 (6.3% vs 7.3% vs 22.8%, P < 0.001) and the proportion of invasive mechanical ventilation also increased among the three groups. Patients with high SAA levels had a longer length of hospital stay compared with patients with medium SAA and low SAA levels. Univariate logistic regression analysis showed that SAA >36 mg/L further increased the odds ratio to 4.423 (P < 0.001) for the development of severe COVID-19 compared with low SAA. Multivariate logistic regression analysis, adjusted for age and sex, confirmed that SAA >36 mg/L remained an independent risk factor for the development of severe COVID-19 (adjusted odds ratio 3.038, P < 0.001). CONCLUSIONS: SAA levels are strongly associated with poor prognosis in patients with COVID-19 and diabetes.

Prognostic Potential of Thrombocyte Indices, Acute Phase Proteins, Electrolytes and Acid-Base Markers in Canine Parvovirus Infected Dogs With Systemic Inflammatory Response Syndrome.

Dogs with canine parvovirus enteritis (CPVE) that develop systemic inflammatory response syndrome (SIRS) frequently have a poor prognosis. The aim of the study was to assess the prognostic potential of thrombocyte indices, acute phase proteins, electrolytes, and acid-base markers in CPVE puppies with SIRS (CPVE-SIRS+) at admission. A case-controlled, prospective, and observational study was performed on 36 CPVE puppies. Mean concentrations of C-reactive protein (CRP), albumin, thrombocyte count, mean platelet volume (MPV), platelet distribution width (PDW), sodium (Na+), potassium (K+), chloride (Cl-) and ionized calcium (iCa) were measured and strong ion difference 3 (SID3), ATOT-albumin and ATOT-total protein were determined in CPVE-SIRS+ survivors and nonsurvivors. A prognostic cut-off value for predicting the disease outcome was determined by receiver operating characteristic (ROC) curve analysis. The mean values of MPV, PDW and CRP were significantly higher and the mean values of albumin, Cl- and ATOT-albumin were significantly lower in CPVE-SIRS+ nonsurvivor than CPVE-SIRS+ survivor puppies on the day of admission, but the thrombocyte count, Na+, K+, iCa, SID3 and ATOT- total protein values did not differ significantly. The positive predictive values (PPVs) for survival using cut-off value of MPV (≤15.08 fL), PDW (≤14.85%), CRP (≤180.7 mg/L), albumin (≥1.795 g/dL), Cl- (≥96.00 mmol/L), and ATOT-albumin (≥7.539) were determined as 100%, 100%, 100%, 80%, 100%, and 80%, respectively with better area under ROC curve and sensitivity. Based on sensitivity, specificity, and PPVs from ROC analysis, it is concluded that the determination of Cl- concentration and MPV at admission followed by CRP will serve as the most appropriate biomarkers in predicting the disease outcome of CPVE puppies that develop SIRS.

Sepsis-mediated renal dysfunction: Pathophysiology, biomarkers and role of phytoconstituents in its management.

Sepsis has evolved as an enormous health issue amongst critically ill patients. It is a major risk factor that results in multiple organ failure and shock. Acute kidney injury (AKI) is one of the most frequent complications underlying sepsis, which portends a heavy burden of mortality and morbidity. Thus, the present review is aimed to provide an insight into the recent progression in the molecular mechanisms targeting dysregulated immune response and cellular dysfunction involved in the development of sepsis-associated AKI, accentuating the phytoconstituents as eligible candidates for attenuating the onset and progression of sepsis-associated AKI. The pathogenesis of sepsis-mediated AKI entails a complicated mechanism and is likely to involve a distinct constellation of hemodynamic, inflammatory, and immune mechanisms. Novel biomarkers like neutrophil gelatinase-associated lipocalin, soluble triggering receptor expressed on myeloid cells 1, procalcitonin, alpha-1-microglobulin, and presepsin can help in a more sensitive diagnosis of sepsis-associated AKI. Many bioactive compounds like curcumin, resveratrol, baicalin, quercetin, and polydatin are reported to play an important role in the prevention and management of sepsis-associated AKI by decreasing serum creatinine, blood urea nitrogen, cystatin C, lipid peroxidation, oxidative stress, IL-1ß, TNF-α, NF-κB, and increasing the activity of antioxidant enzymes and level of PPARγ. The plant bioactive compounds could be developed into a drug-developing candidate in managing sepsis-mediated acute kidney injury after detailed follow-up studies. Lastly, the gut-kidney axis may be a more promising therapeutic target against the onset of septic AKI, but a deeper understanding of the molecular pathways is still required.

Effect of systemic inflammatory response syndrome on thrombocytogram, acute phase proteins, electrolytes, acid-base indices and cytokine expression in naturally canine parvovirus infected dogs.

Systemic inflammatory response syndrome (SIRS) in canine parvoviral enteritis (CPVE) is associated with high mortality in young puppies. Changes in acute phase response, thrombocytogram, inflammatory cytokine profiles, and disturbances in electrolyte and acid-base homeostasis are thought to have a significant impact on the development of SIRS. However, the mechanisms causing these perturbations have not been well described in CPVE puppies, especially with SIRS. The purpose of this study was to assess the changes of electrolytes, acid-base indices using strong ion model, acute phase proteins and thrombocytogram in blood and expressions of inflammatory cytokines in blood mononuclear cells of CPVE puppies with or without SIRS at admission. Additionally, the positive predictive value (PPV) and cut-off value with specificity and sensitivity of the biomarkers were determined by receiver operating characteristic (ROC) curve analysis to predict the development of SIRS in CPVE puppies at admission. A case-controlled, prospective and observational study was conducted on fifteen SIRS-positive CPVE, twenty-one SIRS-negative CPVE and six healthy puppies. Our data showed marked hyponatremia, hypokalemia, hypoalbuminemia and hypoproteinemia, decreased ATot-albumin and ATot-total protein and increased mean platelet volume (MPV), platelet distribution width (PDW) and C-reactive protein (CRP) concentration and up-regulation of TNF-α, IL-8 and IL-10 expressions in SIRS-positive CPVE puppies as compared to SIRS-negative CPVE puppies at admission. Based on sensitivity, specificity and AUC from ROC curve analysis and PPV, the CRP concentration in serum at a cut-off value of 141.9 mg/L and TLC of blood at a cut-off value of 3.355 × 103/µL were identified as potential prognostic biomarkers followed by ATot-total protein and total protein at a cut-off value of 11.80 and 4.72 g/dL, respectively to predict the development of SIRS in CPVE puppies at admission. In conclusion, the findings of the current study will help the canine practitioners to institute the time-sensitive and need based interventions to disrupt progression along the continuum of shock and multi-organ dysfunction syndrome in CPVE puppies that develop SIRS at admission.

Acute phase proteins in cats: Diagnostic and prognostic role, future directions, and analytical challenges.

While clinical studies on acute phase proteins (APPs) have significantly increased in the last decade, and most commercial labs are now offering major APPs in their biochemical profiles, APP testing has not been widely adopted by veterinary clinical pathologists and veterinarians. Measurement of APP concentration is a useful marker for detecting the presence or absence of inflammation in cats with various diseases. APPs can also be reliably measured in different biological fluids (eg, effusions and urine) to improve their diagnostic utility. Measurement of APPs can be extremely beneficial in cats with feline infectious peritonitis (FIP) to discriminate between FIP and non-FIP cats with similar clinical presentations. Additional benefits come from multiple and sequential measurements of APPs, particularly in the assessment of therapeutic efficacy. APPs are more sensitive than WBC counts for early detection of inflammation and to demonstrate an early remission or recurrence of the diseases. Given the potential utility of APPs, more studies are warranted, with a particular focus on the applications of APPs to guide the length of antimicrobial therapies, as suggested by the antimicrobial stewardship policy. New inflammatory markers have been discovered in human medicine, with a higher specificity for distinguishing between septic versus nonseptic inflammatory diseases. It is desirable that these new markers be investigated in veterinary medicine, to further test the power of APPs in diagnostic setting.

L-FABP and NGAL are novel biomarkers for detection of abdominal injury and hemorrhagic shock.

INTRODUCTION: Delayed diagnosis of abdominal injuries and hemorrhagic shock leads to secondary complications and high late mortality in severely traumatized patients. The liver fatty acid-binding protein (L-FABP) is expressed in intestine, liver and kidney; the neutrophil gelatinase-associated lipocalin (NGAL) in colon and kidney. We hypothesized that l-FABP is an early biomarker for abdominal injury and hemorrhagic shock and that l-FABP and NGAL are specific markers for detection of liver and/or kidney injuries. PATIENTS AND METHODS: Traumatized patients with an age ≥18 years and an abdominal injury (AISabd≥2), independently from Injury Severity Score (ISS), were prospectively included from 04/2018 to 05/2021. 68 patients had an abdominal injury ("Abd") and 10 patients had an abdominal injury with hemorrhagic shock ("HS Abd"). 41 patients without abdominal injury and hemorrhagic shock but with an ISS ≥ 25 ("noAbd") were included as control group. Four abdominal subgroups with isolated organ injuries were defined. Plasma l-FABP and NGAL levels were measured at admission (ER) and up to two days post-trauma. RESULTS: All patient groups had a median ISS≥25. In ER, median l-FABP levels were significantly higher in "HS Abd" group (1209.2 ng/ml [IQR=575.2-1780.3]) compared to "noAbd" group (36.4 ng/ml [IQR=14.8-88.5]), and to "Abd" group (41.4 ng/ml [IQR=18.0-235.5]), p<0.001. In matched-pair-analysis l-FABP levels in the group "Abd" were significantly higher (108.3 ng/ml [IQR=31.4-540.9]) compared to "noAbd" (26.4 ng/ml [IQR=15.5-88.8]), p = 0.0016. l-FABP correlated significantly with clinical parameters of hemorrhagic shock; the optimal cut-off level of l-FABP for detection was 334.3 ng/ml (sensitivity: 90%, specificity: 78%). Median l-FABP-levels were significantly higher in patients with isolated liver or kidney injuries and correlated significantly with AST, ALT and creatinine value. Median NGAL levels in the ER were significantly higher in "HS Abd" group (115.9 ng/ml [IQR=90.6-163.8]) compared to "noAbd" group (58.5 ng/ml [IQR=41.0-89.6],p<0.001) and "Abd" group (70.5 ng/ml [IQR=53.3-115.5], p<0.05). The group "Abd" showed significant higher median NGAL levels compared to "noAbd", p = 0.019. NGAL levels correlated significantly with clinical parameters of hemorrhagic shock. CONCLUSION: L-FABP and NGAL are novel biomarkers for detection of abdominal trauma and hemorrhagic shock. l-FABP may be a useful and promising parameter in diagnosis of liver and kidney injuries, NGAL failed to achieve the same.

Evaluation of blood serum iron concentration as an alternative biomarker for inflammation in dairy cows.

This study aimed to clarify the relationship between acute phase protein (APP) concentrations and serum Fe concentrations to determine whether serum iron (Fe) can be clinically applied as a substitute for APPs in cows. One hundred five Holstein-Friesian breed lactating dairy cows were enrolled in this study. Cows with inflammatory diseases were 16 subclinical, and 15 severe mastitis cows, in addition to 15 mild and 16 severe sole ulcer cows. The plasma haptoglobin (HPT), alpha-1 acid glycoprotein (AGP), SAA, serum Fe levels, and other biochemical parameters in the cows were measured. The two-sample t-tests and multiple logistic regression analysis were used to compare the control and inflammatory disease groups. ROC analysis was used to evaluate the ability to diagnose inflammation disease. From the results, the proposed diagnostic cutoff value for plasma SAA and serum Fe concentrations to identify dairy cows with inflammatory diseases based on analyses of ROC curves were set at > 3.65 mg/l and < 120.50 µg/dl, respectively. Therefore, instead of using expensive inflammatory markers to evaluate the inflammatory state at the first treatment day for inflammatory diseases in cow, it shows the useful for screening with serum Fe concentration that can be measured easily and inexpensively as alternative inflammatory biomarkers.

Associations of circulating levels of phthalate metabolites with cytokines and acute phase reactants in a Spanish human cohort.

The associations between human phthalate exposure and the onset of chronic diseases with an immunological component (e.g., metabolic syndrome, cancer) remain unclear, partly due to the uncertainties in the underlying mechanisms. This study investigates cross-sectional associations of the concentrations of 10 phthalate metabolites with 19 cytokines and acute phase proteins in 213 serum samples of Spanish adults. The associations were explored by Spearman's correlation, multivariable linear regression, and weighted quantile sum regression analyses. In the multivariable analyses, levels of plasminogen activator inhibitor (PAI)-1 were positively associated with mono-n-butyl phthalate (fold-change per one IQR increase in phthalate levels, 95% Confidence Interval: 1.65, 1.45-1.88) and mono-iso-butyl phthalate (3.07, 2.39-3.95), mono-ethyl phthalate (2.05, 1.62-2.61), as well as categorized mono-iso-decyl and mono-benzyl phthalates. The same phthalates also were significantly associated with leptin, interleukin (IL)-18 and monocyte chemoattractant protein-1. Moreover, the proinflammatory markers IL-1ß, IL-17, IL-8, IL-6, IL-12, tumor necrosis factor, and lipopolysaccharide-binding protein showed positive and negative associations with, respectively, mono-(2-ethyl-hexyl) and mono-methyl phthalates. Finally, phthalate mixtures were positively associated with PAI-1, leptin, IL-18, IL-12, IL-8 and IL-1ß. Despite the cross-sectional design limitation, these associations point to relevant subclinical immuno-inflammatory actions of these pollutants, warranting confirmation in future studies.

The Inflammation Biomarker GlycA Reflects Plasma N-Glycan Branching.

BACKGROUND: GlycA is a nuclear magnetic resonance (NMR) signal in plasma that correlates with inflammation and cardiovascular outcomes in large data sets. The signal is thought to originate from N-acetylglucosamine (GlcNAc) residues of branched plasma N-glycans, though direct experimental evidence is limited. Trace element concentrations affect plasma glycosylation patterns and may thereby also influence GlycA. METHODS: NMR GlycA signal was measured in plasma samples from 87 individuals and correlated with MALDI-MS N-glycomics and trace element analysis. We further evaluated the genetic association with GlycA at rs13107325, a single nucleotide polymorphism resulting in a missense variant within SLC39A8, a manganese transporter that influences N-glycan branching, both in our samples and existing genome-wide association studies data from 22 835 participants in the Women's Health Study (WHS). RESULTS: GlycA signal was correlated with both N-glycan branching (r2 ranging from 0.125-0.265; all P < 0.001) and copper concentration (r2 = 0.348, P < 0.0001). In addition, GlycA levels were associated with rs13107325 genotype in the WHS (ß [standard error of the mean] = -4.66 [1.2674], P = 0.0002). CONCLUSIONS: These results provide the first direct experimental evidence linking the GlycA NMR signal to N-glycan branching commonly associated with acute phase reactive proteins involved in inflammation.

Markers of inflammation in free-living African elephants (Loxodonta africana): Reference intervals and diagnostic performance of acute phase reactants.

INTRODUCTION: Acute phase reactants (APRs) have not been investigated in free-living African elephants (Loxodonta africana), and there is little information about negative APRs albumin and serum iron in elephants. OBJECTIVES: We aimed to generate reference intervals (RIs) for APRs for free-living African elephants, and to determine the diagnostic performance of APRs in apparently healthy elephants and elephants with inflammatory lesions. METHODS: Stored serum samples from 49 apparently healthy and 16 injured free-living elephants were used. The following APRs and methods were included: albumin, bromocresol green; haptoglobin, colorimetric assay; serum amyloid A (SAA), multispecies immunoturbidometric assay, and serum iron with ferrozine method. Reference intervals were generated using the nonparametric method. Indices of diagnostic accuracy were determined by receiver-operator characteristic (ROC) curve analysis. RESULTS: Reference intervals were: albumin 41-55 g/L, haptoglobin 0.16-3.51 g/L, SAA < 10 mg/L, and serum iron 8.60-16.99 µmol/L. Serum iron and albumin concentrations were lower and haptoglobin and SAA concentrations were higher in the injured group. Serum iron had the best ability to predict health or inflammation, followed by haptoglobin, SAA, and albumin, with the area under the ROC curve ranging from 0.88-0.93. CONCLUSIONS: SAA concentrations were lower in healthy African vs Asian elephants, and species-specific RIs should be used. Serum iron was determined to be a diagnostically useful negative APR which should be added to APR panels for elephants.

Serum acute-phase protein concentrations following uncomplicated total hip arthroplasty in dogs.

OBJECTIVES: To establish preoperative and postoperative serum C reactive protein (CRP) and serum amyloid A (SAA) levels in dogs undergoing uncomplicated total hip arthroplasty (THA). STUDY DESIGN: Prospective clinical trial. ANIMALS: Eighteen client-owned dogs. METHODS: Dogs undergoing THA were recruited. Serum CRP and SAA levels were measured in all dogs the day prior to surgery, and 3 and 6 months following surgery. All dogs received a physical examination and underwent radiography at each visit, and dogs with complications were excluded from the study. For continuous numeric data, histograms were generated and evaluated for normality. A 1-way repeated measures ANOVA was performed to find differences between time points. RESULTS: No complications were encountered in any of the recruited dogs. Median age was 30 months (12-66), and the median bodyweight was 27.3 kg (22.3-40.2). Mean CRP concentrations in the preoperative, 3-month, and 6-month periods were 3.8 mg/L ± 4.4, 0.8 mg/L ± 1.9, and 1.4 mg/L ± 1.4, respectively. The mean SAA concentrations in the preoperative, 3-month, and 6-month periods were 13.9 mg/L ± 8.8, 14.1 mg/L ± 12.6, and 18.4 mg/L ± 15.1, respectively. There were no differences for each parameter between time points. CONCLUSION: C-reactive protein and SAA levels were consistent with levels previously established for noninflammatory and normal conditions in dogs. CLINICAL SIGNIFICANCE: Postoperative CRP and SAA concentrations were low by 3 months following uncomplicated THA.

Use of serum amyloid A in equine medicine and surgery.

Serum amyloid A (SAA) has become an indispensable part of the management of equine patients in general practice and specialized hospital settings. Although several proteins possess acute phase properties in horses, the usefulness of SAA exceeds that of other acute phase proteins. This is due to the highly desirable kinetics of the equine SAA response. SAA concentrations exhibit a rapid and pronounced increase in response to inflammation and a rapid decline after the resolution of inflammation. This facilitates the detection of inflammatory disease and real-time monitoring of inflammatory activity. SAA may be used in all stages of patient management: (1) before diagnosis (to rule in/rule out inflammatory disease), (2) at the time of diagnosis (to assess the severity of inflammation and assist in prognostication), and (3) after diagnosis (to monitor changes in inflammatory activity in response to therapy, with relapse of disease, or with infectious/inflammatory complications). By assessing other acute phase reactants in addition to SAA, clinicians can succinctly stage inflammation. White blood cell counts and serum iron concentration change within hours of an inflammatory insult, SAA within a day, and fibrinogen within 2-3 days; the interrelationship of these markers thus indicates the duration and activity of the inflammatory condition. Much research on the equine SAA response and clinical use has been conducted in the last decade. This is the prerequisite for the evidence-based use of this analyte. However, still today, most published studies involve a fairly low number of horses. To obtain solid evidence for use of SAA, future studies should be designed with larger sample sizes.

Plasma markers of COVID-19 severity: a pilot study.

BACKGROUND: SARS-CoV-2 infected patients show heterogeneous clinical presentations ranging from mild symptoms to severe respiratory failure and death. Consequently, various markers reflect this wide spectrum of disease presentations. METHODS: Our pilot cohort included moderate (n = 10) and severe (n = 10) COVID-19 patients, and 10 healthy controls. We determined plasma levels of nine acute phase proteins (APPs) by nephelometry, and full-length (M65), caspase-cleaved (M30) cytokeratin 18, and ADAMTS13 (a disintegrin-like and metalloprotease with thrombospondin type-1 motif 13) by ELISA. In addition, we examined whole plasma N-glycosylation by capillary gel electrophoresis coupled to laser-induced fluorescence detection (CGE-LIF). RESULTS: When compared to controls, COVID-19 patients had significantly lower concentrations of ADAMTS13 and albumin (ALB) but higher M30, M65, α1-acid glycoprotein (AGP), α1-antitrypsin (AAT), ceruloplasmin (CP), haptoglobin (HP), and high-sensitivity C-reactive protein (hs-CRP). The concentrations of α1-antichymotrypsin (ACT), α2-macroglobulin (A2MG) and serum amyloid A (SAA) proteins did not differ. We found significantly higher levels of AAT and M65 but lower ALB in severe compared to moderate COVID-19 patients. N-glycan analysis of the serum proteome revealed increased levels of oligomannose- and sialylated di-antennary glycans and decreased non-sialylated di-antennary glycan A2G2 in COVID-19 patients compared to controls. CONCLUSIONS: COVID-19-associated changes in levels and N-glycosylation of specific plasma proteins highlight complexity of inflammatory process and grant further investigations.

Systematic evaluation of plasma signaling cascades by functional proteomics approaches: SARS-CoV-2 infection as model.

PURPOSE: Acute phase reactants (APRs) play a critical role in inflammation. The difference in their physiological functions or the different dynamic ranges of these proteins in plasma makes it difficult to detect them simultaneously and to use several of these proteins as a tool in clinical practice. EXPERIMENTAL DESIGN: A novel multiplex assay has been designed and optimized to carry out a high-throughput and simultaneous screening of APRs, allowing the detection of each of them at the same time and in their corresponding dynamic range. RESULTS: Using Sars-CoV-2 infection as a model, it has been possible to profile different patterns of acute phase proteins that vary significantly between healthy and infected patients. In addition, severity profiles (acute respiratory distress syndrome and sepsis) have been established. CONCLUSIONS AND CLINICAL RELEVANCE: Differential profiles in acute phase proteins can serve as a diagnostic and prognostic tool, among patient stratification. The design of this new platform for their simultaneous detection paves the way for them to be more extensive use in clinical practice.

Influence of Short and Medium Distance Road Transport on the Acute Phase Proteins in Horses.

Horse transport is a common practice and is usually associated as a cause of stress in animals, with consequences for their well-being. There are several of evidence that stress can increase an acute phase response. The aim of this study was to verify whether the road transport of horses over distances of 50 and 300 kilometers induces changes in the values of acute phase proteins. To do this, the serum SDS-PAGE was performed and the bands obtained were identified by mass spectrometry (MALDI-TOF). The blood samples were collected in tubes without anticoagulant to obtain the serum, and the evaluations occurred before the road transportation (T0), immediately after the journey (T1), six hours later (T2), and 24 hours (T3), 48 hours (T4), 72 hours (T5), 96 hours (T6), 120 hours (T7) and 144 hours (T8) after the end of the trip. All analyzes were performed using the Minitab 17 statistical package, and significance was considered when P<0.05. The APPs found through SDS-PAGE and properly identified were α2-macroglobulin, ceruloplasmin, transferrin, albumin, α1-antitrypsin, haptoglobin, apolipoprotein alpha 1, and α1-acid glycoprotein. No differences were observed in the concentration values between 50 and 300 km or between the moments after each route. The distances covered with the horses were not challenging enough to provoke an acute phase response reflected in changes in APPs.

Evaluation of a point-of-care benchtop analyzer for quantitative measurement of C-reactive protein in canine serum and plasma.

BACKGROUND: Canine C-reactive protein (cCRP) is an acute-phase protein that increases dramatically with inflammation and has potential utility in monitoring disease progression and response to treatment. Rapid, automated point-of-care test (POCT) formats could enhance the clinical utility of cCRP measurement. OBJECTIVES: We aimed to evaluate the VetChroma canine-specific POCT assay for the quantitative measurement of cCRP in canine serum or plasma. METHODS: Serum and plasma from discarded canine diagnostic samples were used. Evaluation included intra- and inter-assay coefficients of variation and observed total error (TEobs ), linearity and spike recovery, the effect of interfering substances and sample matrices, and a method comparison study. RESULTS: Intra-assay variation ranged from 2.5%-6.1%, and inter-assay variation ranged from 2.1%-5.4%. The TEobs ranged from 15.1%-19.7%. The assay was linear over the manufacturer's analytical range with no evidence of constant or proportional bias. Recovery of purified cCRP from canine serum ranged from 116.2% to 138.4%. Hemolysis, icterus, and turbidity did not interfere with the assay. The comparison of paired plasma and serum samples revealed constant and proportional bias. Comparison of the VetChroma cCRP assay to a commercial cCRP ELISA revealed significantly different results. CONCLUSIONS: The VetChroma cCRP assay has acceptable test performance to measure serum cCRP concentration. The POCT protocol and test kit are valid for clinical use, although results obtained using other cCRP assays or plasma may not be directly compared.

Identification of CD14 and lipopolysaccharide-binding protein as novel biomarkers for sarcoidosis using proteomics of serum extracellular vesicles.

Sarcoidosis is a complex, polygenic, inflammatory granulomatous multi-organ disease of unknown cause. The granulomatous inflammation in sarcoidosis is driven by the interplay between T cells and macrophages. Extracellular vesicles (EVs) play important roles in intercellular communication. We subjected serum EVs, isolated by size exclusion chromatography, from seven patients with sarcoidosis and five control subjects to non-targeted proteomics analysis. Non-targeted, label-free proteomics analysis detected 2292 proteins in serum EVs; 42 proteins were up-regulated in patients with sarcoidosis relative to control subjects; and 324 proteins were down-regulated. The protein signature of EVs from patients with sarcoidosis reflected disease characteristics such as antigen presentation and immunological disease. Candidate biomarkers were further verified by targeted proteomics analysis (selected reaction monitoring) in 46 patients and 10 control subjects. Notably, CD14 and lipopolysaccharide-binding protein (LBP) were validated by targeted proteomics analysis. Up-regulation of these proteins was further confirmed by immunoblotting, and their expression was strongly increased in macrophages of lung granulomatous lesions. Consistent with these findings, CD14 levels were increased in lipopolysaccharide-stimulated macrophages during multinucleation, concomitant with increased levels of CD14 and LBP in EVs. The area under the curve values of CD14 and LBP were 0.81 and 0.84, respectively, and further increased to 0.98 in combination with angiotensin-converting enzyme and soluble interleukin-2 receptor. These findings suggest that CD14 and LBP in serum EVs, which are associated with granulomatous pathogenesis, can improve the diagnostic accuracy in patients with sarcoidosis.

Review of immunological plasma markers for longitudinal analysis of inflammation and infection in rat models.

Disease or trauma of orthopedic tissues, including osteomyelitis, osteoporosis, arthritis, and fracture, results in a complex immune response, leading to a change in the concentration and milieu of immunological cells and proteins in the blood. While C-reactive protein levels and white blood cell counts are used to track inflammation and infection clinically, controlled longitudinal studies of disease/injury progression are limited. Thus, the use of clinically-relevant animal models can enable a more in-depth understanding of disease/injury progression and treatment efficacy. Though longitudinal tracking of immunological markers has been performed in rat models of various inflammatory and infectious diseases, currently there is no consensus on which markers are sensitive and reliable for tracking levels of inflammation and/or infection. Here, we discuss the blood markers that are most consistent with other outcome measures of the immune response in the rat, by reviewing their utility for longitudinal tracking of infection and/or inflammation in the following types of models: localized inflammation/arthritis, injury, infection, and injury + infection. While cytokines and acute phase proteins such as haptoglobin, fibrinogen, and α2 -macroglobulin demonstrate utility for tracking immunological response in many inflammation and infection models, there is likely not a singular superior marker for all rat models. Instead, longitudinal characterization of these models may benefit from evaluation of a collection of cytokines and/or acute phase proteins. Identification of immunological plasma markers indicative of the progression of a pathology will allow for the refinement of animal models for understanding, diagnosing, and treating inflammatory and infectious diseases of orthopedic tissues.

Acute-phase proteins in cats with obstructive feline lower urinary tract disease.

BACKGROUND: Feline obstructive disease of the lower urinary tract (FLUTD) is a common pathologic condition of cats. It can be related to sterile inflammation, which leads to acute impairment of renal function and the accumulation of electrolytes and acid-base imbalance. Acute-phase proteins (APPs) are biomarkers of tissue damage from inflammation that assist in monitoring treatment and prognosis. OBJECTIVE: Monitoring the inflammatory processes of obstructive feline lower urinary tract disease through the determination of plasma fibrinogen concentrations and serum concentrations of the acute-phase proteins, serum amyloid A (SAA), alpha-1-acid glycoprotein (AGP), and albumin. METHODOLOGY: Twenty-five male cats were included in this study. They were divided into two experimental groups: a control group (CG) and an obstruction group (OG). There were 8 healthy cats in the CG group and 17 cats with obstructive FLUTD in the OG group. APP measurements were conducted using ELISA kits. Samples were collected for APP analyses, serum biochemical assays, urinalyses, and urine protein: creatinine ratio calculations at diagnosis, before urethral clearance (H0), and 12 (H12), 24 (H24), and 48 (H48) hours after urethral clearance from cats in the OG group. Samples were collected once from cats in the CG group cats. RESULTS: At H0, we found positive correlations of SAA, AGP, and fibrinogen with urea and creatinine, and negative correlations of albumin with hematuria, SAA, and potassium. At H48, we found positive correlations between SAA and AGP, AGP and urea, fibrinogen and urea, fibrinogen and creatinine, fibrinogen and AGP, and fibrinogen and SAA. In addition, a negative correlation of albumin with urea and creatinine was observed. CONCLUSIONS: Serum amyloid A, AGP, fibrinogen, and albumin could be used as biomarkers of inflammatory processes in cats with obstructive FLUTD.

Relationship Between Acute Phase Reactants and Disability in Guillian-Barré Syndrome During the COVID-19 Pandemic.

BACKROUND: Guillain-Barré syndrome (GBS) is an immune-mediated disease that affects the peripheral nervous system and may occur after some bacterial-viral infections. AIM: The aim of this study is to determine and compare the epidemiological, clinical and laboratory characteristics of the patients followed up in our clinic with the diagnosis of GBS in the 15 month periods before and after March 2020. At the same time, we aimed to examine the importance of these markers as prognostic indicators by investigating the relationship of D-dimer, CRP, albumin and transferrin levels with Hughes functional grading scale score (HFGSS). MATERIAL AND METHODS: The medical files of the patients who were followed up with the diagnosis of GBS between December 2018 and May 2021 were retrospectively analyzed. The patients were divided into groups as pandemic, pre-pandemic, post-COVID-19 and non-COVID-19. Epidemiological and clinical characteristics of GBS patients and plasma D-dimer, serum albumin, CRP and transferrin levels were recorded. RESULTS: No significant difference was found between the pandemic and pre-pandemic periods in terms of age, gender, GBS subtype, seasonal distribution and treatment characteristics of GBS patients. PostCOVID-19 GBS patients had significantly higher HFGSS both at admission and at discharge (p <0.05). In post-COVID-19 GBS patients good-excellent negative correlation between transferrin and albumin levels and HFGSS at hospital admission and discharge, positive correlations with CRP levels were observed. CONCLUSION: Post-COVID-19 GBS patients had worse HFGSS at both admission and discharge. CRP was positively correlated with HFGSS whereas transferrin and albumin showed negative correlation with HFGSS.