CardioDetect rapid test for the diagnosis of early acute myocardial infarction.

Two hundreds patients suspected of acute myocardial infarction presenting to the hospital with a median symptom onset of 2.3 h (IQR 1.7-4.0 h) were enrolled in this study. The diagnostic performances of CardioDetect®, a one-step immunotest for heart-type fatty acid-binding protein (H-FABP), and its combination with cardiac troponin I (cTnI) at admission and 2 h after admission, were compared with different cardiac markers. The H-FABP immunotest had better sensitivities (76.6% and 94.4%) than the other cardiac markers and better specificities (88.2% and 81.7%) than myoglobin at admission and 2 h after admission. Both sensitivity and negative predictive value increased to over 90.0% at 2 h after admission. The areas under the receiver operator characteristic curve for the combination of H-FABP with cTnI were the greatest at admission [0.834 (95% CI: 0.774-0.894)].

Diagnostic utility of an anti-CCP point-of-care immunotest in Chinese patients with rheumatoid arthritis.

BACKGROUND: Early and accurate diagnosis of rheumatoid arthritis (RA) has become increasingly important. The clinical significance of anti-cyclic citrullinated peptide (CCP) antibody in Chinese RA adults was studied using an anti-CCP2 rapid test. METHODS: Anti-CCP antibody and rheumatoid factor (RF) were determined in 95 RA patients and 140 patients with rheumatic diseases other than RA. RESULTS: Two hundred and thirty five subjects were enrolled in this study. Both sensitivity and specificity of anti-CCP2 ELISA (78.9% & 95.7%) were higher than those of RF (67.4% & 84.3%). The area under the receiver operating characteristic curve for anti-CCP2 ELISA was 0.852 (95% CI: 0.792-0.913) which was larger than that for RF 0.775 (95% CI: 0.710-0.840). Both sensitivity and specificity (75.8% and 92.9%) of the anti-CCP2 rapid test were comparable to the ELISA. However, the sensitivity (62.1%) of a combined strategy by measuring anti-CCP antibody and RF was even lower than either marker alone although the specificity (98.6%) was slightly improved. CONCLUSIONS: Anti-CCP antibody is a valuable tool for diagnosis of RA in Chinese patients. With the use of the reliable and user-friendly anti-CCP rapid test, it may have an important role in the design of therapeutic strategies in RA patients.

A one-step immunotest for rapid detection of heart-type fatty acid-binding protein in patients with acute coronary syndromes.

Using heart-type fatty acid-binding protein (H-FABP) as an early cardiac marker for diagnosis of acute myocardial infarction (AMI) soon after the onset of symptoms requires a rapid assay. A one-step test called, CardioDetect, is used for detection of H-FABP in whole blood sample. Thirty patients suspected of AMI presenting to the emergency department within 12 hours after onset were enrolled in this study. The diagnostic performance of CardioDetect was compared with different cardiac markers. There were 59.1% of patients with positive H-FABP within 6 hours after onset, while there were only 18.2% with positive cardiac troponin I (cTnI). Results indicated the diagnostic power of H-FABP for AMI was significantly higher than that of cTnI. The sensitivity of H-FABP was 81.8%, which was higher than those of the other cardiac markers, while the specificity was comparable. The area under the receiver operating characteristic curve for H-FABP was 0.909, which was significantly larger than the others. With this rapid and sensitive immunotest, H-FABP could be soon introduced in clinical practice in combination with well-established markers like troponins.

Human heart-type fatty acid-binding protein for on-site diagnosis of early acute myocardial infarction.

Human heart-type fatty acid-binding protein (H-FABP) has a high potential as an early marker for acute myocardial infarction (AMI) being more sensitive than current routine cardiac markers. Seventy-four patients presenting to hospital with a median symptom onset of 2.2 h (IQR 1.5-2.9 h) were enrolled in this study and 54 (73%) had AMI. At presentation, H-FABP gave the highest sensitivity of 83.3% (95% CI: 70.7-92.1) and troponin I (cTnI) gave the highest specificity of 50.0% (95% CI: 27.2-72.8). This study demonstrated that H-FABP immunotest gave a better diagnostic classification at the early stage. Also, AMI was identified significantly earlier by H-FABP than cTnI (17 vs. 6 patients, p<0.05).

Diagnostic utility of CRP to neopterin ratio in patients with acute respiratory tract infections.

OBJECTIVES: In this study we aimed to investigate the roles of neopterin, C-reactive protein (CRP) and the CRP to neopterin (C/N) ratio to differentiate bacterial from viral aetiology in patients with suspected acute respiratory tract infections (ARTIs) presenting to the emergency department (ED). METHODS: Serum was taken from five hundred and sixty-one patients and used to measure neopterin and CRP levels. The primary outcome was bacterial or viral infection based on positive bacterial culture and positive viral serology. Patients were classified as either: group 1 with positive bacterial culture and mixed bacterial/viral growth; group 2 with virological aetiology, and group 3 with unknown microbiological aetiology. RESULTS: The median of the C/N ratio was 10 times higher in patients with bacterial aetiology than with viral aetiology (12.5 vs 1.2mg/nmol; P<0.0001), and 42 times higher than those in healthy subjects (12.5 vs 0.3mg/nmol; P<0.0001). The area under the receiver-operator characteristic curve for the C/N ratio was 0.840 (0.783-0.898; P<0.05). A cut-off value of "C/N ratio >3" for ruling in/out bacterial/viral infection yielded optimal sensitivity and specificity of 79.5% and 81.5% respectively. A sensitivity analysis performed on all patients (including unknown aetiology) with a cut-off value of "C/N ratio >3" yields a best-case scenario for ruling in/out bacterial/viral infection with sensitivity of 93.1% and specificity of 93.0%. CONCLUSION: This study shows that CRP and neopterin have a role in differentiating bacterial from viral causes of ARTI, and the C/N ratio yields optimal differentiation in the ED setting.

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.

Detection of serum neopterin for early assessment of dengue virus infection.

OBJECTIVE: Neopterin is generated and released in increased amounts by macrophages upon activation by interferon-gamma during Th1-type immune response. The potential usefulness of neopterin in early prognostic information of dengue virus infection was investigated. METHODS: Neopterin concentrations were determined in serum samples from 110 dengue fever (DF) patients. The neopterin levels were compared with those in 50 measles and 40 influenza patients; 155 healthy blood donors served as controls. RESULTS: In acute sera of DF patients mean neopterin concentration was 48.2 nmol/L, which was higher than that in patients with measles (mean: 36.3 nmol/L) and influenza (18.8 nmol/L) and in healthy controls (6.7 nmol/L; P<0.001). In the patients with confirmed DF, an early neopterin elevation was detected already at the first day after the onset of symptoms and rose to a maximum level of 54.3 nmol/L 4 days after the onset. Higher increase of neopterin level in DF patients was associated with longer duration of fever and thus predicted the clinical course of the disease. CONCLUSIONS: Neopterin concentrations were found significantly higher in DF patients compared with healthy controls and also with other viral infections (P<0.001) and may allow early assessment of the severity of DF.

Serum neopterin for early assessment of severity of severe acute respiratory syndrome.

Neopterin and C-reactive protein (CRP) concentrations were determined in serum samples from 129 severe acute respiratory syndrome (SARS) patients and 156 healthy blood donors. In the patients with confirmed SARS, an early neopterin elevation was detected already at the day of onset of symptoms and rose to a maximum level of 45.0 nmol/L 3 days after the onset. All SARS patients had elevated neopterin concentrations (>10 nmol/L) within 9 days after the onset. The mean neopterin concentrations were 34.2 nmol/L in acute sera of SARS patients, 5.1 nmol/L in convalescent sera, and 6.7 nmol/L in healthy controls. In contrast, the mean CRP concentrations in both acute and convalescent sera of SARS patients were in the normal range (<10 mg/L). Serum neopterin level in SARS patients was associated with fever period and thus the clinical progression of the disease, while there was no significant correlation between the CRP level and the fever period. Serum neopterin may allow early assessment of the severity of SARS. The decrease of neopterin level was found after steroid treatment, which indicates that blood samples should be collected before steroid treatment for the neopterin measurement.