The acute-phase proteins serum amyloid A and C reactive protein in transudates and exudates

Simplified Light's Criteria and Acute Phase Proteins Reflect Aetiology of Feline Body Cavity Effusions Better than the Traditional Classification Scheme

The traditional veterinary classification (TVC) of effusions based on cell count and total protein (TP) does not adequately reflect the aetiology. Light's criteria (LC) (activity of lactate dehydrogenase [LDH] in the effusion [LDHef], effusion/serum LDH ratio [LDHr], effusion/serum TP ratio [TPr]), serum-effusion albumin gradient (ALBg), acute phase proteins (APPs) [serum amyloid A (SAA), α₁-acid glycoprotein (AGP), haptoglobin] might aid classification. The aim was to evaluate the utility of these parameters except LDHr in differentiating exudates from transudates. Sixty-five cats with effusions (33 peritoneal, 31 pleural, 1 pericardial), with 18 transudates and 47 exudates based on aetiological classification (AC), were included. The sensitivity, specificity and accuracy of several parameters to identify exudates (based on AC) was assessed. APPs were compared between exudates and transudates based on AC and TVC, with receiver operating characteristics analysis identifying the best APP to recognise exudates. Simplified LC (LDHef, TPr) had an accuracy of 79% and TVC of 48%. ALBg had the highest sensitivity (98%) and LDHef the highest specificity (83%) in identifying exudates in cats. All APPs but effusion SAA could differentiate exudates from transudates based on AC (effusion AGP had the largest area under the curve 0.79) but not TVC. All parameters were better than TVC in identifying exudates. The conformity of APPs with AC but not TVC favours the use of AC to classify effusions.

Metal-enhanced sensing platform for the highly sensitive detection of C-reactive protein antibody and rhodamine B with applications in cardiovascular diseases and food safety

The potential applications of metal-enhanced fluorescence (MEF) devices include biosensors for the detection of trace amounts in biosciences, biotechnology, and pathogens that are relevant to medical diagnostics and food control. In the present study, the silver (Ag) film thickness (56 nm) of an MEF system was calibrated to maximize the depth-to-width ratio (Γ) of the surface plasmon resonance (SPR) active metal from reflectance dip curves. Upon plasmon coupling with thermally evaporated Ag, we demonstrated a 2.21-fold enhancement compared to the pristine flat substrate with the coefficient of variation (CV) ≈0.22% and the limit of detection (LOD) 0.001 mg L-1 of the concentration of an Alexa Fluor 488-labeled anti-C-reactive protein antibody (CRP@Alexa fluor 488). The structure was developed to simplify the in situ generation of biosensors for the surface-enhanced Raman spectroscopy (SERS) to determine Rhodamine B (RhB) with a highly robust performance. The procedure presented a simple and rapid sample pretreatment for the determination of RhB with a limit of quantification of 10-10 M and a satisfactory linear response (0.98). The results showed the excellent performance of the surface plasmon coupled emission (SPCE), which opens up possibilities for the accurate detection of small-volume and low-concentration target analytes due to the improved sensitivity and signal-to-noise ratio (SNR).

Amyloid A in Serum and Ascitic Fluid as a Novel Diagnostic Marker of Spontaneous Bacterial Peritonitis

Background: Diagnosis of Spontaneous Bacterial Peritonitis (SBP) depends mainly on ascetic fluid culture which may be negative in spite of the clinical suggestion of SBP and high ascetic fluid neutrophilic count.

Aims: This study aimed to evaluate the biological importance of amyloid A biomarker in both serum and ascetic fluid to diagnose SBP as early as possible and to compare it to other markers (C-reactive protein (CRP), and the neutrophil-to-lymphocyte ratio (NLR)).

Methods: This study included 37 patients with hepatic ascites; twenty-two of them had SBP, and 15 patients did not have SBP. Serum and ascetic fluid amyloid A, ascetic fluid neutrophil, C-reactive protein, and neutrophil-to-lymphocyte ratio were measured in all subjects before the start of antimicrobial chemotherapy to the infected ones.

Results: Both the serum and ascetic fluid amyloid and also, CRP were significantly higher in patients infected with ascetic fluid than others. The cut-off point of serum amyloid A for early detection of SBP was 9.25ug/ml with the high sensitivity and specificity. For ascetic amyloid A, the sensitivity and specificity were 90.09% and 60% at cut-off point 2.85ug/ml, respectively.

Conclusion: Amyloid A in serum and ascitic fluid can be considered as a good biomarker for early diagnosis of SBP.

Serum amyloid A levels in acute and chronic urticaria

BACKGROUND

Serum amyloid A is an acute-phase protein. There is no available data regarding serum amyloid A levels in patients with acute (AU) and chronic urticaria (CU).

OBJECTIVE

To investigate the association between serum amyloid A and urticaria.

METHODS

This was a case-control study of 81 patients who visited our Hospital between June and December 2016 with a diagnosis of urticaria. Eighty healthy controls (HC) who visited for routine health examination and physical checkups were recruited. Serum amyloid A and C-reactive protein levels were measured by automated methods.

RESULTS

Serum amyloid A and C-reactive protein levels were significantly higher in AU (Serum amyloid A: 207.1 (6.7-439.0) mg/L; C-reactive protein: 16.0 (0.2-90.0) mg/L) and CU (Serum amyloid A: 6.5 (2.5-35.8) mg/L; C-reactive protein: 1.0 (0.1-16.0) mg/L) compared with HC (Serum amyloid A: 5.04 (2.0-9.1) mg/L; C-reactive protein: 1.2 (0.1-5.6) mg/L), and in AU compared with CU (all P<0.05). There were no differences between the CU and HC group. In CU, Serum amyloid A levels in those with moderate/severe urticaria (median, 16.4 (9.7-35.8) mg/L) were higher than in those with mild urticaria (median, 5.7 (2.5-9.5) mg/L) and HC (all P<0.05). Serum amyloid A and C-reactive protein levels exceeded the normal lab range in 90.7% and 72.1% patients with AU compared with 28.9% and 13.2% patients with CU, respectively. Significant positive correlations were found between serum amyloid A and C-reactive protein (r = 0.562, P < 0.001).

STUDY LIMITATIONS

There was no comparison between active disease and remission.

CONCLUSION

There was an association between serum amyloid A levels and urticaria. Higher serum amyloid A levels were associated with AU and more severe CU. Serum amyloid A may help to identify CU patients earlier.

Acute phase protein haptoglobin as inflammatory marker in serum and synovial fluid in an equine model of arthritis

Acute phase proteins are useful inflammatory markers in horses. Haptoglobin (Hp) serum level is increased in horses undergoing different inflammatory processes, including arthritis. However, Hp concentration has not been assessed in inflammatory synovial fluid (SF). The aim of the present study was to investigate the Hp response in serum and SF in horses undergoing experimentally induced arthritis. For this purpose, serum and SF samples were collected from 12 animals before amphotericin B-induced arthritis was created (T0, healthy) and 15days after the lesion induction (T1, joint inflammation) and Hp was determined by single radial immunodiffusion. The Hp increase between T0 and T1 was significant in both serum and SF, and serum Hp concentration at T0 was significantly higher than in SF, but significant differences were not found at T1, indicating a higher Hp increase in SF. A significant positive correlation for Hp concentration between serum and SF samples was found. These results highlight the potential usefulness of Hp as inflammatory marker in horses, showing for the first time the increase of Hp in SF from joint inflammation in the horse.

Significance of serum and ascitic fluid C-reactive protein in differential diagnosis of benign and malignant ascites

BACKGROUND

The values of C-reactive protein (CRP) can prove useful in determining disease progress. Because of synthesis by the liver, production of CRP in response to inflammation may be attenuated in patients with liver dysfunction. This may result in differences interpreting CRP levels in patient with portal and non-portal hypertension ascites.

AIM

The aim of the present study is to assess discriminant value of serum and ascitic fluid CRP, which is easily accessible and inexpensive laboratory marker of inflammation, concentrations for diagnosis of underlying cause of ascites.

METHODS

This prospective study was conducted at Dıskapı Yıldırım Beyazıt Educational and Research Hospital Department of Gastroenterology. Patients with ascites were further divided into two subgroups based on underlying cause of ascites: Group 1, patient with ascites due to portal hypertensive etiology (high-gradient ascites); Group 2, patient with ascites due to non-portal hypertensive etiology (low-gradient ascites).

RESULTS

A total of 91 patients fulfilling the criteria for a diagnosis of ascites were enrolled in the study. Of these patients, 50 had proven (Group 1) ascites due to portal hypertensive etiology (high-gradient ascites) and 41 had clinical (Group 2) ascites due to non-portal hypertensive etiology (low-gradient ascites). Mean baseline serum and ascites levels of CRP were significantly higher in Group 2 compared to those in Group 1 (p = 0.021, p = <0.0001, respectively).

CONCLUSIONS

Increased levels of serum and ascitic fluid CRP were associated with malignant ascites.

Oleic, linoleic and linolenic acids increase ros production by fibroblasts via NADPH oxidase activation

The effect of oleic, linoleic and γ-linolenic acids on ROS production by 3T3 Swiss and Rat 1 fibroblasts was investigated. Using lucigenin-amplified chemiluminescence, a dose-dependent increase in extracellular superoxide levels was observed during the treatment of fibroblasts with oleic, linoleic and γ-linolenic acids. ROS production was dependent on the addition of β-NADH or NADPH to the medium. Diphenyleneiodonium inhibited the effect of oleic, linoleic and γ-linolenic acids on fibroblast superoxide release by 79%, 92% and 82%, respectively. Increased levels of p47^phox phosphorylation due to fatty acid treatment were detected by Western blotting analyses of fibroblast proteins. Increased p47^phox mRNA expression was observed using real-time PCR. The rank order for the fatty acid stimulation of the fibroblast oxidative burst was as follows: γ-linolenic > linoleic > oleic. In conclusion, oleic, linoleic and γ-linolenic acids stimulated ROS production via activation of the NADPH oxidase enzyme complex in fibroblasts.

Serum amyloid alpha in parapneumonic effusions

STUDY OBJECTIVES

To assess serum amyloid alpha (SAA) pleural fluid levels in parapneumonic effusion (PPE) and to investigate SAA diagnostic performance in PPE diagnosis and outcome.

METHODS

We studied prospectively 57 consecutive patients with PPE (empyema (EMP), complicated (CPE), and uncomplicated parapneumonic effusion (UPE)). SAA, CRP, TNF-α, IL-1β, and IL-6 levels were evaluated in serum and pleural fluid at baseline. Patients were followed for 6-months to detect pleural thickening/loculations.

RESULTS

Pleural SAA levels (mg/dL) median(IQR) were significantly higher in CPE compared to UPE (P < 0.04); CRP levels were higher in EMP and CPE compared to UPE (P < 0.01). There was no significant difference between IL-1β, IL-6, TNF-α level in different PPE forms. No significant association between SAA levels and 6-month outcome was found. At 6-months, patients with no evidence of loculations/thickening had significantly higher pleural fluid pH, glucose levels (P = 0.03), lower LDH (P = 0.005), IL-1β levels (P = 0.001) compared to patients who presented pleural loculations/thickening.

CONCLUSIONS

SAA is increased in complicated PPE, and it might be useful as a biomarker for UPE and CPE diagnosis. SAA levels did not demonstrate considerable diagnostic performance in identifying patients who develop pleural thickening/loculations after a PPE.

Serum amyloid A induces reactive oxygen species (ROS) production and proliferation of fibroblast

Serum amyloid A (SAA) levels are elevated highly in acute phase response and elevated slightly and persistently in chronic diseases such as rheumatoid arthritis and diabetes. Given that fibroblasts exert profound effects on progression of inflammatory chronic diseases, the aim of this study was to investigate the response of fibroblasts to SAA. A dose-dependent increase in O(2) (-) levels was observed by treatment of fibroblasts with SAA (r = 0·99 and P ≤ 0·001). In addition, the expression of p47-phox was up-regulated by SAA (P < 0·001) and diphenyliodonium (DPI), a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor, reduced the release of O(2) (-) by 50%. Also, SAA raised fibroblast proliferation (P < 0·001) and this effect was completely abolished by the addition of anti-oxidants (P < 0·001). These findings support the notion that, in chronic inflammatory sites, SAA activated fibroblast proliferation and ROS production.