Serum C-reactive Protein Tests Research Articles

Synovial Fluid C-reactive Protein Clinical Decision Limit and Diagnostic Accuracy for Periprosthetic Joint Infection.

Introduction C-reactive protein (CRP) has long served as a prototypical biomarker for periprosthetic joint infection (PJI). Recently, synovial fluid (SF)-CRP has garnered interest as a diagnostic tool, with several studies demonstrating its diagnostic superiority over serum CRP for the diagnosis of PJI. Although previous studies have identified diagnostic thresholds for SF-CRP, they have been limited in scope and employed various CRP assays without formal validation for PJI diagnosis. This study aimed to conduct a formal single clinical laboratory validation to determine the optimal clinical decision limit of SF-CRP for the diagnosis of PJI. Methods A retrospective analysis of prospectively collected data was performed using receiver operating characteristic (ROC) and area under the curve (AUC) analyses. Synovial fluid samples from hip and knee arthroplasties, received from over 2,600 institutions,underwent clinical testing for PJI at a single clinical laboratory (CD Laboratories, Zimmer Biomet, Towson, MD) between 2017 and 2022. Samples were assayed for SF-CRP, alpha-defensin, white blood cell count, neutrophil percentage, and microbiological culture. After applying selection criteria, the samples were classified with the 2018 ICM PJI scoring system as "infected," "not infected," or "inconclusive." Data were divided into training and validation sets. The Youden Index was employed to optimize the clinical decision limit. Results A total of 96,061 samples formed the training (n = 67,242) and validation (n = 28,819) datasets. Analysis of the biomarker median values, culture positivity, anatomic distribution, and days from aspiration to testing revealed nearly identical specimen characteristics in both the training set and validation set. SF-CRP demonstrated an AUC of 0.929 (95% confidence interval (CI): 0.926-0.932) in the training set, with an optimal SF-CRP clinical decision limit for PJI diagnosis of 4.45 mg/L. Applying this cutoff to the validation dataset yielded a sensitivity of 86.1% (95% CI: 85.0-87.1%) and specificity of 87.1% (95% CI: 86.7-87.5%). No statistically significant difference in diagnostic performance was observed between the validation and training sets. Conclusion This study represents the largest single clinical laboratory evaluation of an SF-CRP assay for PJI diagnosis. The optimal CRP cutoff (4.45 mg/L) for PJI, which yielded a sensitivity of 86.1% and a specificity of 87.1%, is specific to the assay methodology and laboratory performing the assay. We propose that an SF-CRP test with a laboratory-validated optimal clinical decision limit for PJI may be preferable, in a clinical diagnostic setting, to serum CRP tests that do not have laboratory-validated clinical decision limits for PJI.

Predictive value of Serum C-Reactive protein and serum lactate in intestinal obstruction with suspected strangulation

Background: Intestinal obstruction is one of the common clinical problems encountered in surgical practice, and the dreadful complication of intestinal obstruction is strangulation, which requires an emergency surgery for management. The main objective of our study was to evaluate patients with clinical suspicious intestinal obstruction and to find out the significant levels of serum C-reactive protein (CRP) and serum lactate in the early detections of strangulation preoperatively. Materials and Methods: A total of 30 patients who aged between 15 and 80 years were included in the study after excluding the patients of comorbid medical illness and patients with findings other than obstruction or strangulation. The serum values of CRP and lactate were measured pre-operatively and compared between obstruction with strangulation and obstruction without strangulation. Receiver operating characteristic (ROC) curve was drawn, and cut-off values for the diagnosis of strangulation were calculated along the calculation of sensitivity, specificity, positive predictive values (PPVs) and negative predictive values (NPVs). Results: Fifteen patients of strangulated bowel obstruction had significantly higher values of serum CRP and lactate when compared with 15 patients of simple bowel obstruction (99 vs. 38.3 mg/L and 35 vs. 9.9 mg/dl, respectively, P < 0.05). Using ROC analysis, the area under the curve of serum CRP and lactate was found to be 0.809 and 0.947, respectively for bowel strangulation. The serum CRP test has the sensitivity of 80.0%, specificity of 66.7%, PPV of 70.6% and NPV of 76.9% to detect the obstruction with strangulation when using a cut-off value of 49 mg/L. The serum lactate test has the sensitivity of 86.7%, specificity of 73.3%, PPV of 76.5% and NPV of 84.6% to detect the obstruction with strangulation when using a cut-off value of 19 mg/dl. Conclusion: The serum CRP and lactate are useful and reasonable diagnostic markers for predicting strangulation in cases of acute intestinal obstruction in an emergency setting.

Association of Various Biomarkers and Liver Enzymes with Severity of COVID-19

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing novel coronavirus (COVID-19) outbreak has an impact on the liver enzymes. The study aimed to determine the serum markers and liver enzymes and their association in COVID-19 patients admitted to hospital. Methods: It was a retrospective, observational study conducted at the Gastroenterology Department of Lahore General Hospital, from April 2020-July 2020. Total 495 patients were divided into two groups. Group A (318) comprised of patients with moderate symptoms and group B (177) with severe symptoms. Records were obtained from the hospital laboratory in which Lactate dehydrogenase (LDH), Aspartate aminotransferase, (AST), Alanine aminotransferase (ALT), Gamma glutamyl transferase (GGT) and Alkaline phosphatase (ALP) were assessed using an automated biochemistry analyzer. Serum C-reactive protein test was performed by the immunoturbidimetric assays. Serum Ferritin was determined using the ELISA technique. Results: The mean age of moderate cases was 48.57±16.84 years and of severe cases were 62.51±9.76 years. In both moderate and severe cases, males [200(63%), 98(55.36%)] were more affected than females [118(37.10%), 79(44.63%)]. Furthermore, 79(16%) of severe cases were associated with medical profession. The levels of CRP, Ferritin and LDH were increased significantly in severe COVID-19 cases (p&lt;0.05) compared to moderate ones. On the other hand, liver enzymes ALT, AST, GGT and ALP were non-significantly raised in severe cases compared to moderate cases (p&gt; 0.05). Conclusion: Serum ferritin, C-reactive protein and lactate dehydrogenase acts as prognostic biochemical parameters based on severity. In addition, levels of liver enzymes were also raised indicating liver derangement; however, the results were not significant. Keywords: Ferritin; C-Reactive Protein; Lactate Dehydrogenase; Gama Glutamyl Transferase; Covid-19.

Effect of miR-26b on gestational diabetes mellitus in rats via PI3K/Akt signaling pathway.

The aim of this study was to explore the influence of micro ribonucleic acid (miR)-26b on gestational diabetes mellitus in rats via the phosphatidylinositol 3-hydroxy kinase/protein kinase B (PI3K/Akt) signaling pathway. A total of 60 healthy pregnant female rats were randomly divided into three groups, including group A (normal group), group B (model group), and group C (model + miR-26b group). The differences in fasting blood glucose (FBG), C-reactive protein (CRP), and phosphatidylinositol 3-hydroxy kinase/protein kinase B (PI3K/AKT) among the three groups were analyzed via serum CRP test, morphological observation, quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR), and Western blotting, respectively. The levels of FBG ad CRP were significantly up-regulated in group B when compared with group A (p<0.01). Meanwhile, they increased significantly in group C when compared with group B (p<0.01). Rats in group A exhibited smooth and flat thoracic aortic intimas, as well as neatly arranged smooth muscle cells at the media layer. However, rats in group B showed fractured intimas with enlarged junction gaps, as well as necrotic and detached endothelial cells. Compared with group B, group C exhibited extremely poorly arranged cells at all the layers, rough and rugged intimas, larger areas of necrotic and detached endothelial cells, and markedly worsened lesions. QRT-PCR results indicated that the expression of phosphorylated-PI3K (p-PI3K) was significantly lower in group B than that of group A (p=0.04). Meanwhile, it was markedly lower in group C than that in group B (p=0.04). The expression of p-Akt was remarkably lower in group B than group A (p=0.04), which was also significantly lower in group C than group B (p=0.04). Compared with group A, the expressions of p-PI3K and p-Akt in the thoracic aorta of group B were evidently down-regulated (p<0.01). Furthermore, they decreased markedly in group C when compared with group B (p<0.01). MiR-26b accelerates the progression of gestational diabetes by inhibiting the PI3K/Akt signaling pathway.

Study of Association of C-Reactive Protein with Maternal Chorioamnionitis and Early-Onset Neonatal Sepsis in Premature Rupture of Membranes Deliveries: A Diagnostic Dilemma.

Introduction:Term prelabor rupture of membranes and preterm premature rupture of membranes (PROM), both pose significant risk to the mother and the fetus. Early identification of sepsis is essential as the mother has risk of chorioamnionitis and neonate is at the risk of early-onset sepsis.Aim:To evaluate the diagnostic value of positive maternal C-reactive protein (CRP) in association with maternal clinical chorioamnionitis and early-onset neonatal sepsis (EONS) in PROM deliveries after 28 weeks of gestation.Methodology:The study was conducted at People's College of Medical Science and Research Centre, Bhopal, from June 1, 2017, to May 31, 2018. Maternal serum CRP test was correlated to the signs of maternal chorioamnionitis and signs of EONS within 72 h of life.Results:The maternal CRP test was compared to clinical signs of chorioamnionitis. Sensitivity of CRP for diagnosing maternal chorioamnionitis was 48% (95% confidence interval [CI] −35.99–61.12), specificity was 81 (95% CI 71.55%–88.98%), and odds ratio of maternal chorioamnionitis was 4.1176 (95% CI 1.99–8.51) with P < 0.0001. Sensitivity of positive maternal CRP in diagnosing EONS was 56.67% (95% CI 43.24%–69.41%), specificity was 84.78% (95% CI 75.79%–91.42%), and odds ratio of neonatal sepsis in maternal CRP positive was 7.28 (95%CI 3.39–15.64) with P < 0.0001.Conclusion:Our study suggests that in PROM deliveries, if maternal CRP test is positive, then it indicates early delivery and neonate screening for EONS.

Influence of periodontitis and scaling and root planing on insulin resistance and hepatic CD36 in obese rats

The aim of the study was to explore the influence of periodontitis and scaling and root planing (SRP) on insulin resistance and hepatic CD36 in obese rats with periodontitis. Thirty-two specific pathogen free Sprague-Dawley rats were randomly divided into four groups of eight animals each as follows: healthy rats (healthy group), obese rats (obesity group), obese rats with periodontitis (non-therapy group), and obese rats with periodontitis who underwent periodontal SRP (therapy group). Rats were fed with a high-fat diet for 16weeks to build an obesity model. Periodontal inflammation was induced by performing periodontal ligation with Porphyromonas gingivalis. The tissue around the maxillary second molars, bilaterally, were collected. The periodontal attachment level (from the cemento-enamel junction to the bottom of the periodontal pocket) of the second molars was measured in all groups. All rats were subjected to fasting blood glucose, insulin, and serum C-reactive protein tests (CRP). Insulin resistance was evaluated by homeostasis model assessment of insulin resistance (HOMA-IR), oral glucose tolerance test (OGTT), and area under the curve (AUC). The liver was excised to detect intrahepatic free fatty acid (FFA) levels and pathologic observation. Real-time quantification PCR, western blot, and immunohistochemistry were applied to detect hepatic CD36 expression. Compared with the obesity group, HOMA-IR, AUC, intrahepatic FFA, and protein expression, and mRNA levels of hepatic CD36 in the non-therapy group were significantly increased (P<0.05). HOMA-IR, AUC, CRP, protein expression, and mRNA levels of hepatic CD36 were all significantly decreased (P<0.05) 2-weeks after SRP. Periodontitis increases insulin resistance while scaling and root planning could improve insulin resistance. Hepatic CD36 regulation may be considered a potential mechanism for this phenomenon.

Diagnostic performance of serum high-sensitivity procalcitonin and serum C-reactive protein tests for detecting bacterial infection in febrile neutropenia

Although a few prospective studies have addressed the question as to which biomarker of infection in adult patients with febrile neutropenia (FN) is superior, procalcitonin (PCT) or C-reactive protein (CRP), the results have been inconsistent and inconclusive. This was possibly due to the poor sensitivity of previous PCT tests that have a functional sensitivity of 0.5 ng/ml. Between November 2010 and February 2012, we prospectively compared the diagnostic utility of serum high-sensitivity (hs) PCT (lower limit of detection, 0.02 ng/ml) and CRP levels for detecting bacterial infection in patients with FN. Serum was collected within 72 h after the onset of FN in patients with hematological disorders. Seventy-five febrile episodes were evaluable. The areas under the receiver operating characteristic curves for life-threatening infection defined as septic shock and bacteremia caused by non-coagulase negative staphylococcus were 0.824 (95% CI 0.711-0.937; P = 0.001) for hsPCT and 0.673 (0.505-0.842; P = 0.068) for CRP, respectively. In contrast, CRP, but not hsPCT, tended to increase significantly with the clinical severity, as indicated by the diagnostic classification (P = 0.002 for trend). The serum hsPCT test may be more useful than the serum CRP test in the detection of life-threatening infection at an early phase after the onset of FN. In contrast, the serum CRP test may be more useful in diagnosing the severity of infection. However, neither of these tests was able to differentiate the cause of FN with a low probability of fatal outcome.

Dynamics of serum C-reactive protein (CRP) level and cosmophysical activity

Background C-reactive protein (CRP), an acute phase reactant, plays an important part in the investigation of the role of inflammation in pathology. Many cardiovascular events show significant associations with various cosmophysical parameters. The aim of this study was to investigate the relationship between the level of CRP and the levels of solar, geomagnetic (GMA), and cosmic ray activity. Methods The results of 25,399 serum CRP tests carried out over a 3-year period were compared with the monthly and daily levels of solar, geomagnetic, and cosmic ray activity during the same period. The cosmophysical data were obtained from the National Oceanic Atmospheric Administration (NOAA) in the U.S. and from the Russian Academy of Science. Results On a monthly basis, CRP levels showed no correlation with GMA ( n = 36, r = 0.258, p = 0.13), but there was a significant inverse relationship with neutron activity ( r = − 0.35, p = 0.03). For the daily comparisons, CRP levels were significantly correlated with GMA ( n = 1057, r = 0.97, p = 0.02), and there was a significant inverse relationship with neutron activity ( r = − 0.97, p = 0.025). Daily neutron activity was higher on days with CRP levels of 0–1.0 mg/dl ( n = 289) and above1.0–1.5 mg/dl ( n = 1213) than on days with higher CRP values (> 1.5; n = 23,897; p < 0.0001). Conclusion The level of serum CRP, in addition to its association with inflammation, is related to the daily level of GMA and inversely to the level of neutron activity.

Human serum “parvovirus”: A specific cause of aplastic crisis in children with hereditary spherocytosis

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Serum C-reactive protein test in diagnosis of septic complications of cerebrospinal fluid shunts for hydrocephalus.

Serial tests for serum C-reactive protein (CRP) were carried out on 40 children undergoing cerebrospinal fluid shunt surgery, to determine the pattern of appearance and disappearance of CRP in relation to this type of operation, in the absence of postoperative complications. Samples of sera from a further 268 children, 79 of whom presented after shunt surgery with symptoms suggesting infective complications related to the shunt, were examined for CRP. The results showed that, while the test in negative in uncomplicated colonisation of ventriculo-atrial shunts, it is reliably positive in patients with colonised ventriculo-peritoneal shunts, ventriculitis, or shunt nephritis.