InfectCheck CRP barcode-style lateral flow assay for semi-quantitative detection of C-reactive protein in distinguishing between bacterial and viral infections.

In the present study, we describe an InfectCheck barcode-style lateral flow assay for semi-quantitative detection of CRP in distinguishing between bacterial and viral infections. The severity of bacterial infection can be assessed by simply counting the number of red lines developed at the CRP test zone of the test device. If only one visible line appeared at the CRP test zone, it represents a low or mild inflammation with CRP levels <10 mg/L. Two and three visible lines mean moderate (>or=10-25 mg/L) and severe (>or=25-50 mg/L) inflammations respectively while four visible lines stand for a very severe inflammation (>or=50-100 mg/L). If the visible lines become faint and the intensity of the first line is weaker than that of the control line and may even disappear, this outcome corresponds to the stage of having super severe inflammation (>or=100 mg/L). A total of 500 patients admitted to hospital through the Accident and Emergency Unit at the Prince of Wales Hospital were examined. The InfectCheck CRP barcode-style rapid test gave a high sensitivity of 88.7% and a high negative predictive value of 93.8%. This result indicates that the rapid test is reliable to exclude non-infected patients. The calculated intra- and inter-assay coefficient of variation for the five CRP concentration ranges was both within 20.0%. It is a one-step whole blood rapid test without any sample pre-treatment and the result is available within 20 min. This user friendly diagnostic tool can allow self-testing by interested individuals without any expensive reading device.

[1]  N Rifai,et al.  Clinical efficacy of an automated high-sensitivity C-reactive protein assay. , 1999, Clinical chemistry.

[2]  M. Leinonen,et al.  White blood cells, C-reactive protein and erythrocyte sedimentation rate in pneumococcal pneumonia in children. , 1997, The European respiratory journal.

[3]  M. Siimes,et al.  Quantitative C‐reactive Protein (CRP) Determined by an Immunoturbidimetric Method in Rapid Differential Diagnosis of Acute Bacterial and Viral Diseases of Children , 1984, Acta paediatrica Scandinavica.

[4]  L. Olaison,et al.  C-Reactive protein is more sensitive than erythrocyte sedimentation rate for diagnosis of infective endocarditis , 1997, Infection.

[5]  D. Fuchs,et al.  Value of serum procalcitonin, neopterin, and C-reactive protein in differentiating bacterial from viral etiologies in patients presenting with lower respiratory tract infections. , 2007, Diagnostic microbiology and infectious disease.

[6]  P. Ridker,et al.  Inflammation, aspirin, and the risk of cardiovascular disease in apparently healthy men. , 1997, The New England journal of medicine.

[7]  H. Peltola,et al.  Simplified treatment of acute staphylococcal osteomyelitis of childhood. The Finnish Study Group. , 1997, Pediatrics.

[8]  A. Philip,et al.  Use of C-Reactive Protein in Minimizing Antibiotic Exposure: Experience With Infants Initially Admitted to a Well-Baby Nursery , 2000, Pediatrics.

[9]  Thomas Francis,et al.  SEROLOGICAL REACTIONS IN PNEUMONIA WITH A NON-PROTEIN SOMATIC FRACTION OF PNEUMOCOCCUS , 1930, The Journal of experimental medicine.

[10]  H. Gewurz,et al.  Radioimmunoassay of human C-reactive protein and levels in normal sera. , 1976, The Journal of laboratory and clinical medicine.

[11]  L H Kuller,et al.  Relationship of C-reactive protein to risk of cardiovascular disease in the elderly. Results from the Cardiovascular Health Study and the Rural Health Promotion Project. , 1997, Arteriosclerosis, thrombosis, and vascular biology.

[12]  N Rifai,et al.  Evaluation of nine automated high-sensitivity C-reactive protein methods: implications for clinical and epidemiological applications. Part 2. , 2001, Clinical chemistry.

[13]  Harry,et al.  C-reactive protein induces human peripheral blood monocytes to synthesize tissue factor. , 1993, Blood.

[14]  L. Hansson,et al.  Sequential changes of inflammatory and nutritional markers in patients with community-acquired pneumonia. , 1997, Scandinavian journal of clinical and laboratory investigation.

[15]  L. Kuller,et al.  Relation of C-reactive protein and coronary heart disease in the MRFIT nested case-control study. Multiple Risk Factor Intervention Trial. , 1996, American journal of epidemiology.

[16]  P. Andrews,et al.  Rapid determination of C-reactive protein levels: semiquantitative versus quantitative. , 1987, The Journal of pediatrics.

[17]  G. Lowe,et al.  Immunoradiometric assay of circulating C-reactive protein: age-related values in the adult general population. , 2000, Clinical chemistry.

[18]  S. Chanock,et al.  Assessment of measuring circulating levels of interleukin-6, interleukin-8, C-reactive protein, soluble Fc gamma receptor type III, and mannose-binding protein in febrile children with cancer and neutropenia. , 1999, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America.

[19]  J. Sipe,et al.  Analytical Evaluation of Particle-Enhanced Immunonephelometric Assays for C-Reactive Protein, Serum Amyloid a and Mannose-Binding Protein in Human Serum , 1998, Annals of clinical biochemistry.

[20]  M. V. van Dieijen-Visser,et al.  High-sensitivity C-reactive protein methods examined. , 2002, Clinical chemistry.

[21]  J. Gauldie,et al.  Acute phase proteins , 1985 .

[22]  S. Ballou,et al.  C-reactive protein and the acute phase response. , 1992, Advances in internal medicine.

[23]  G. Edelman,et al.  Binding properties and specificity of C-reactive protein. , 1967, Proceedings of the National Academy of Sciences of the United States of America.

[24]  D. Ballot,et al.  Use of C‐reactive protein to guide duration of empiric antibiotic therapy in suspected early neonatal sepsis , 2000, The Pediatric infectious disease journal.

[25]  P. Mackie,et al.  C-reactive protein for rapid diagnosis of infection in leukaemia. , 1979, Journal of clinical pathology.

[26]  R. Delemos,et al.  C-reactive protein levels in the extremely premature infant: case studies and literature review. , 1998, Journal of perinatology : official journal of the California Perinatal Association.

[27]  J. Volanakis,et al.  C-reactive protein , 1997, Immunologic research.

[28]  M. Perry.  Erythrocyte sedimentation rate and C reactive protein in the assessment of suspected bone infection--are they reliable indices? , 1996, Journal of the Royal College of Surgeons of Edinburgh.