Laboratory Evaluation of a New Lateral-Flow-Based Point-of-Care Rapid Test for Assessment of Chronic Systemic Inflammation

Abstract

Abbreviations: (CRP) C-reactive protein, (CVD) cardiovascular disease, (hs) high sensitivity, (POC) point of careKeywords: cardiovascular disease, chronic systemic inflammation, high-sensitivity C-reactive protein, point-of-care rapid test AbstractThe determination of C-reactive protein (CRP) by means of a highly sensitive laboratory method as an independent biomarker for assessment of chronic systemic vascular inflammation and cardiovascular risk is recommended by therapeutic guidelines for diabetes and cardiovascular disease in the United States and in Europe. The purpose of this investigation was to investigate the specificity and sensitivity of a newly developed lateral-flow-based point-of-care (POC) rapid test with semi-quantitative visual reading in comparison with a laboratory reference standard method.The high-sensitivity CRP concentrations of 66 samples were determined by means of turbidimetry and the POC test (5 µl serum/10 µl capillary whole blood, 10 minutes) was independently performed by three investigators blinded to each other's results. The visual readings were classified, as recommended by the American Heart Association, to represent a low risk (0-1 mg/liter), moderate risk (>1-3 mg/liter), or high risk (>3-10 mg/liter) or to indicate an unspecific inflammation (>10 mg/liter).According to the reference method, there were 17 samples in the low-risk group, 19 samples in the moderaterisk group, and 26 samples in the high-risk group, and 4 samples showed an unspecific inflammation. All three investigators reached very conclusive results. The range of agreement between the visual readings of the investigators and the laboratory method ranged between 94% and 97%. The sensitivity for assessment of moderate-to-high cardiovascular risk was 100% (45/45 were detected), and the specificity ranged between 90% and 95%.The newly developed lateral-flow-based POC rapid test showed an excellent agreement between individual visual reading and the laboratory reference method. It may therefore be suitable for a fast and convenient screening, which, after laboratory test confirmation, may help to identify patients with elevated risk of macrovascular disease.

Diagnostic accuracy and clinical role of rapid C-reactive protein testing in HIV-infected individuals with presumed tuberculosis in South Africa

“…31 Two semi-quantitative tests use a test cassette and reagent buffer, without a machine, and provide information on CRP being less than or greater than 10 mg/l. 32 Although we evaluated a variety of CRP levels, we used a CRP > 8 mg/l since it is commonly used in rapid tests, has been reported in prior studies, 33,34 and maximizes diagnostic sensitivity. In 2012, the average price of 3 rapid CRP machines was Euro (€) 1,837, and €4 per test.…”

Validation and evaluation of eight commercially available point of care CRP methods

“…However, we did not manually correct for Ht, as this is in general not possible in POC situations. Several POC CRP analyzers have already been evaluated by others [4][5][6][7][8][9][10] but all except one [10] in a one to one comparison with a central laboratory method. The correlation coefficients are in general N0.95 comparable with our findings.…”

“…There are many commercially available methods for POC CRP, with various pre-analytical handling and varying assay performance [4][5][6][7][8]. In one method the measurement of the white blood cell count is combined with that of CRP [9].…”

Vertical flow immunoassay (VFA) biosensor for a rapid one-step immunoassay

“…The CRP level is considered normal up to 3 mg L 21 , and abnormal at levels higher than 5 mg L 21 . [18][19][20] When compared to different markers for acute myocardial infarction (MI), such as cardiac troponin and myoglobin, the assay for hsCRP requires measurement of rather high concentrations of the protein (¢1 mg L 21 ). 21,22 In this study, we report the development of a new vertical flow one-step immunoassay (VFA) system (Scheme 1) that provides rapid results (within 2 min, to complete the reaction), requires relatively small sample volumes and provides a wide detection range with sensitivity similar to that of conventional LFA methods.…”