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Biosensors May 2022C-reactive protein (CRP) is an important part of the immune system's reaction to various pathological impulses such as bacterial infections, systemic inflammation, and... (Review)
Review
C-reactive protein (CRP) is an important part of the immune system's reaction to various pathological impulses such as bacterial infections, systemic inflammation, and internal organ failures. An increased CRP level serves to diagnose the mentioned pathological states. Both standard laboratory methods and simple point-of-care devices such as lateral flow tests and immunoturbidimetric assays serve for the instrumental diagnoses based on CRP. The current method for CRP has many flaws and limitations in its use. Biosensor and bioassay analytical devices are presently researched by many teams to provide more sensitive and better-suited tools for point-of-care tests of CRP in biological samples when compared to the standard methods. This review article is focused on mapping the diagnostical relevance of CRP, the applicability of the current analytical methods, and the recent innovations in the measurement of CRP level.
Topics: C-Reactive Protein; Humans; Inflammation; Point-of-Care Systems; Point-of-Care Testing; Sensitivity and Specificity
PubMed: 35624645
DOI: 10.3390/bios12050344 -
Pediatric Rheumatology Online Journal Dec 2022Haptoglobin (Hp), a liver derived acute phase inflammatory protein (APP), has scarcely been studied in juvenile idiopathic arthritis (JIA). Hp can occur in blood as two...
BACKGROUND
Haptoglobin (Hp), a liver derived acute phase inflammatory protein (APP), has scarcely been studied in juvenile idiopathic arthritis (JIA). Hp can occur in blood as two isoforms (Hp1 and Hp2) in precursor and mature forms. Routine clinical chemistry immunoturbidimetry does not discern these forms. It is unknown how different forms relate to disease activity in JIA. Our aims were to determine allele frequency and plasma concentrations of different Hp forms at higher versus lower JIA disease activity and compare to other APPs.
METHODS
Plasma from JIA (n = 77) and healthy (n = 42) children were analyzed for apparent Hp allelic frequency and densitometric concentrations of alpha forms by Western blot (WB). Polymerase chain reaction (PCR) (buffy coat) was performed in a subset to estimate conformity with genetics. At higher versus lower juvenile arthritis disease activity score (JADAS27) (which includes erythrocyte sedimentation rate (ESR)), total mature Hp concentration from WB was compared and correlated against immunoturbidimetry and total protein, albumin, serum amyloid A (SAA) and C-reactive protein (CRP).
RESULTS
At 300-fold dilution needed to study mature forms in Western blot, precursors were undetectable. Hp2 contributed most signal in most samples. Hp allele frequency was similar in JIA and controls. Both mature forms, taken separately or by sum, declined following treatment, but remained above concentrations of healthy controls, even in a remission subset that achieved JADAS27 < 1. Densitometry correlated with immunoturbidimetry. Hp concentrations correlated with JADAS27, albumin (negatively), CRP and SAA with immunoturbidimetric method correlating strongest to JADAS27 (Spearman R ~ 0.6, p < 0.0001).
CONCLUSION
Hp allele frequency in JIA is similar to the general population, indicating that children with JIA should have the same possibility as in healthy children to produce preHp2 (zonulin), thought to increase intestinal permeability. Circulating Hp concentrations largely parallel other APPs and ESR; none of these measures correlate very strongly to JADAS27 score but Hp can be measured from capillary sampling which is impossible with ESR.
Topics: Child; Humans; Arthritis, Juvenile; Haptoglobins; Blood Sedimentation; C-Reactive Protein; Health Status
PubMed: 36517828
DOI: 10.1186/s12969-022-00777-5 -
Journal of Clinical Laboratory Analysis May 2014SPAPLUS™ is a turbidimetric immunoassay analyzer for detection of excess free light chain (FLC) antigens in serum. Here, we evaluated the analytical performance of... (Comparative Study)
Comparative Study
BACKGROUND
SPAPLUS™ is a turbidimetric immunoassay analyzer for detection of excess free light chain (FLC) antigens in serum. Here, we evaluated the analytical performance of Freelite™ Human Kappa Free and Lambda Free on a SPAPLUS™ instrument.
METHODS
We evaluated the precision, linearity, sample carryover, and drift of the SPAPLUS™ instrument and compared it with Hitachi 7600 and BN™ II instruments. We evaluated the detection of antigen excess for 12 specimens from patients with monoclonal gammopathy.
RESULTS
The coefficients of variations of κFLC and λFLC were below 5.0%. Linearity was shown in the range of 9.68-152.25 mg/l for κFLC and 4.96-171.09 mg/l for λFLC, and no drift was observed. The κFLC sample carryover was statistically significant, but much smaller than the optimum allowable bias. Agreement rates with the two comparative methods were 87.1, 87.1, and 97.1% or higher for κFLC, λFLC, and the κ/λ ratio, respectively. Antigen excess signals were observed for all 12 antigen excess specimens.
CONCLUSIONS
The Freelite™ on the SPAPLUS™ exhibited appropriate precision, linearity, and relative comparability to the reagents on the other instruments. It was good at detecting specimens that had previously demonstrated the hook effect due to antigen excess.
Topics: Humans; Immunoassay; Immunoglobulin Light Chains; Nephelometry and Turbidimetry; Paraproteinemias; Sensitivity and Specificity
PubMed: 24478145
DOI: 10.1002/jcla.21671 -
American Journal of Hematology Apr 2019von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) by platelet aggregometry has been considered the gold standard for evaluating the ability of VWF to... (Review)
Review
von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) by platelet aggregometry has been considered the gold standard for evaluating the ability of VWF to bind platelets for over 40 years. Many automated systems no longer require platelets and rather rely on agglutination of latex particles. Automated methods of measuring VWF activity have improved performance characteristics and are performed on the same coagulation instruments used for routine testing via immunoturbidimetric methodology. Alternatively, a newer chemiluminescence assay system for measuring VWF activity demonstrates excellent performance characteristics. As these methods are becoming widely used, it is important to assess their performance in diagnosing and monitoring different types of von Willebrand disease. We review the automated methodologies and the published performance of these VWF assays. Advantages and limitations of these automated methods are discussed.
Topics: Automation, Laboratory; Blood Coagulation Tests; Blood Platelets; History, 20th Century; History, 21st Century; Humans; von Willebrand Factor
PubMed: 30592326
DOI: 10.1002/ajh.25393 -
Hamostaseologie Nov 2020Heparin-induced thrombocytopenia (HIT) is an antibody-mediated hypercoagulable state featuring high thrombosis risk and distinct pathogenesis involving immunoglobulin... (Review)
Review
Heparin-induced thrombocytopenia (HIT) is an antibody-mediated hypercoagulable state featuring high thrombosis risk and distinct pathogenesis involving immunoglobulin G-mediated platelet activation. The target of the immune response is a cationic "self" protein, platelet factor 4 (PF4), rendered antigenic by heparin. A key problem is that only a minority of anti-PF4/polyanion antibodies induced by heparin are pathogenic, i.e., capable of causing platelet activation and thereby clinical HIT. Since thrombocytopenia occurs frequently in hospitalized, heparin-treated patients, testing for "HIT antibodies" is common; thus, the problem of distinguishing between pathogenic and nonpathogenic antibodies is important. The central concept is that those antibodies that have platelet-activating properties demonstrable in vitro correlate well with pathogenicity, as shown by platelet activation tests such as the serotonin-release assay (SRA) and heparin-induced platelet activation assay. However, in most circumstances, immunoassays are used for first-line testing, and so it is important for clinicians to appreciate which immunoassay result profiles-in the appropriate clinical context-predict the presence of platelet-activating antibodies (Bayesian analysis). Clinicians with access to rapid, on-demand HIT immunoassays (e.g., particle gel immunoassay, latex immunoturbidimetric assay, chemiluminescent immunoassay) can look beyond simple dichotomous result interpretation ("negative"/"positive") and incorporate semiquantitative interpretation, where, for example, a strong-positive immunoassay result (or even combination of two immunoassays) points to a greater probability of detecting platelet-activating antibodies, and hence supporting a diagnosis of HIT. Recent recognition of "SRA-negative HIT" has increased the importance of semiquantitative interpretation of immunoassays, given that strong immunoassay reactivity is a potential clue indicating possible HIT despite a (false) negative platelet activation assay.
Topics: Antibodies; Heparin; Humans; Thrombocytopenia
PubMed: 33091948
DOI: 10.1055/a-1223-3329 -
Veterinary Clinical Pathology Feb 2022C-reactive protein (CRP) is a positive acute-phase protein, serum concentrations of which increase nonspecifically in response to inflammatory processes of the dog. As... (Review)
Review
C-reactive protein (CRP) is a positive acute-phase protein, serum concentrations of which increase nonspecifically in response to inflammatory processes of the dog. As such, it can aid in the identification of inflammatory disease and, maybe more importantly, the objective monitoring of disease progression. In dogs, CRP is frequently used to evaluate dogs with gastrointestinal diseases, such as chronic inflammatory enteropathies (also termed idiopathic inflammatory bowel disease), acute pancreatitis, canine parvovirus infection, hepatic disease, acute abdomen, and protein-losing enteropathy. The diversity of the assays available to measure CRP in dogs is nearly as numerous as the diseases in which serum concentrations of this protein are increased. Assay methodologies include laser nephelometric immunoassays, enzyme-linked immunosorbent assays, immunoturbidimetric assays, and time-resolved immunofluorometric assays. While many of these assays are acceptable for clinical use in the dog, the same assay and analyzer should be used to measure a patient's CRP concentration longitudinally. By looking at the uses of CRP in human gastroenterology, including reducing the duration of antibiotic therapy, the veterinary profession can gain insight into novel ways in which serum CRP concentration measurements might be applied in veterinary medicine in the future.
Topics: Acute Disease; Animals; C-Reactive Protein; Dog Diseases; Dogs; Gastrointestinal Diseases; Pancreatitis; Reproducibility of Results
PubMed: 35014071
DOI: 10.1111/vcp.13100 -
Renal Failure Dec 2023Diabetic kidney disease (DKD) is one of the most common chronic complications of type 2 diabetes mellitus (T2DM), and it is particularly important to identify a...
BACKGROUND
Diabetic kidney disease (DKD) is one of the most common chronic complications of type 2 diabetes mellitus (T2DM), and it is particularly important to identify a high-quality method for evaluating disease progression. Urinary exosomes contain microRNA that might promise early diagnostic and monitoring markers of DKD. The present study aimed to identify novel exosome-related markers associated with inflammation and fibrosis to assess the progression of DKD.
METHOD
Exosomes were extracted from the urine of 83 participants to determine the expression levels of miRNA-615-3p and miRNA-3147 in 20 healthy people, 21 patients with T2DM and 42 patients with DKD, as determined by RT-qPCR. The circulating expression level of TGF-β1 was detected by ELISA. Serum Cystatin C was measured by a latex-enhanced immunoturbidimetric method. The correlation analyses were performed for all clinical and laboratory parameters.
RESULT
The expression level of urinary exosomal miRNA-615-3p in DKD patients was significantly higher than that in the control group and the T2DM group by RT-qPCR. The expression of miRNA-3147 showed an upward trend in the three groups of subjects, but it was not statistically significant. The urinary exosomal miRNA-615-3p was positively correlated with serum Cystatin C, plasma TGF-β1, creatinine, BUN, PCR and 24-h urine protein, and negatively correlated with eGFR and albumin. The diagnostic efficacy of urinary exosomal miRNA-615-3p combined with the ACR was higher than that of ACR alone.
CONCLUSIONS
Urinary exosomal miRNA-615-3p may be used as a novel biomarker for evaluating the progression of DKD, and may be involved in the process of inflammation and fibrosis in DKD. The combined diagnosis of urinary exosomal miRNA-615-3p and ACR may be used as more stable and sensitive diagnostic criteria for DKD.
Topics: Humans; MicroRNAs; Diabetic Nephropathies; Cystatin C; Transforming Growth Factor beta1; Diabetes Mellitus, Type 2; Biomarkers; Inflammation; Fibrosis
PubMed: 36695327
DOI: 10.1080/0886022X.2022.2121929 -
Annales de Biologie Clinique Dec 2018The quantification of urine albumin is a common practice in Medical Biology laboratories. It allows the assessment of renal injury in common pathologies and many studies...
The quantification of urine albumin is a common practice in Medical Biology laboratories. It allows the assessment of renal injury in common pathologies and many studies have confirmed its role in the diagnosis and prognosis of these disorders. The physicochemical characteristics of albumin in the urine, very different from those in the blood, do not allow the use of the same standardized assay techniques for the blood albumin determination and make it difficult its quantification. Indeed, because of a physiological fragmentation phenomenon, urinary albumin is present in the urine as various small specific peptides. We will present here the main methods of determination of albumin in the urine, which are immuno-turbidimetric and immuno-nephelometric methods, high performance liquid chromatography with steric exclusion and liquid chromatography coupled with mass spectrometry. Currently, immunoanalysis techniques are the most used and are not standardized; large bias can be found between the different kits. This observation calls for a standardization of its determination in the urine.
Topics: Albuminuria; Chromatography, High Pressure Liquid; Chromatography, Liquid; Humans; Immunoassay; Nephelometry and Turbidimetry; Reference Standards; Serum Albumin; Tandem Mass Spectrometry; Urinalysis; Urine Specimen Collection
PubMed: 30543187
DOI: 10.1684/abc.2018.1390 -
Journal of Family Medicine and Primary... Apr 2021Pregnancy is characterized by multiple changes in the coagulation system which occurs at different stages of the condition, representing one of the major triggers of...
BACKGROUND AND AIM
Pregnancy is characterized by multiple changes in the coagulation system which occurs at different stages of the condition, representing one of the major triggers of maternal and foetal morbidity/mortality in the world during complicated incidences. This study determined the prevalence of coagulation disorders among pregnant women in Southwest Nigeria to buttress the need for prompt and accurate routine diagnosis of these disorders.
METHODS
Four hundred and five participants (405) attending some selected tertiary health facilities in Southwestern Nigeria were randomly recruited for the study, comprising two hundred and seventy (270) pregnant subjects and one hundred and thirty-five (135) apparently healthy age- and socio-economic status-matched non-pregnant women as controls. The platelet count was assessed; prothrombin time and activated partial thromboplastin time were assessed. Immunoturbidimetric and chromogenic techniques were also used to assess the level of D-dimer and activated protein C resistance.
RESULTS
Platelet count, PT and INR in all three trimesters were significantly (p < 0.05) reduced when compared to the non-pregnant control subjects. However, the level of circulating D-dimer was significantly (p < 0.05) increased in all three trimesters when compared with the control group, with observable steady increase in the second and third trimesters. Also, 13% of respondents had thrombotic predisposition and 14.8% with tendencies for consumption coagulopathy while 1.1% are APCr positive individuals.
CONCLUSION
The study affirms the hypercoagulable state of pregnancy coupled with mild gestational thrombocytopenia which could be pointers to onset of coagulation disorders in some participants, subjects with coagulation profiles indicative of thrombotic tendencies and possible onset of consumption coagulopathy and the presence of activated protein C resistant in the region. A review of the coagulation monitoring strategies for pregnant women from primary care to include more definite assays and its proper implementation will immensely contribute to early diagnosis along with intervention for pregnancy associated coagulopathies in resource-limited settings.
PubMed: 34123901
DOI: 10.4103/jfmpc.jfmpc_1381_20 -
Practical Laboratory Medicine Aug 2016When a clinical assay is stressed with extraordinarily high volume of specimens over a short period of time, extra caution may be needed to avoid systematic errors and...
OBJECTIVES
When a clinical assay is stressed with extraordinarily high volume of specimens over a short period of time, extra caution may be needed to avoid systematic errors and biases. Here we report our experience with a HgbA1c assay used for high volume wellness screening purpose, to illustrate the importance of stress testing during assay validation.
DESIGN AND METHODS
Over 15,000 whole blood specimens were tested for HgbA1c in a period of 2 months. HgbA1c was tested by an immunoturbidimetric method on a high through-put automation line. The HgbA1c population distribution in our study was compared to that from the NHANES database. Daily distributions of HgbA1c values ≥6%, means and medians were plotted. Correlation studies were performed between the high through-put immunoturbidimetric assay and a medium through-put HPLC method.
RESULTS
We observed a shift of HgbA1c distribution to the higher values compared to the NHANES. A bias of 15-20% was noted from further stress testing where large number of samples were batched and tested using the immunoturbidimetric assay. A 5-7% higher bias remained after implementing a cuvette washing program after each HgbA1c sample. We hypothesized this bias was caused by build-up of blood cell fragments in the cuvettes when continuous whole blood samples are run through the system. Our experience suggests stress testing needs to be incorporated early in the test validation process for high volume batched screening applications. This seemingly extra validation step may save significant troubleshooting and retesting efforts down the road.
PubMed: 28856200
DOI: 10.1016/j.plabm.2016.03.001