Diagnostic value of two immunoassays for detecting heparin/PF4 complex antibodies in heparin-induced thrombocytopenia / 中华血液学杂志

Objectives@#To assess the diagnostic values of latex immunoturbidimetric assay (LIA) and particle immunofiltration assay (PIFA) for heparin-induced thrombocytopenia (HIT) .@*Methods@#Samples from 94 patients with suspected HIT from May 2016 to July 2018 in our hospital were prospectively analyzed by the two immunoassays. Their medical records and further follow-up data were also collected and analyzed by our hematologists to make the 4Ts scores and confirm the diagnosis of HIT, respectively. Performance characteristics of the two immunoassays were assessed, including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) . Their post-test probabilities (PTP) were also calculated based on the 4Ts score.@*Results@#Among 94 cases, 15 (16.0%) had a positive HIT, including 6 of 37 (16.2%) with an intermediate, and 9 of 15 (60.0%) with a high 4Ts score. PIFA operating characteristics were: sensitivity 100.0% (15/15) , specificity 51.9% (41/80) , PPV 28.3% (15/53) , NPV 100.0% (41/41) . The positive PTP in intermediate and high 4Ts score group were 28.7% and 75.7%, respectively, while negative PTP were all 0. At manufacturers’ cutoffs, LIA operating characteristics were: sensitivity 66.7% (10/15) , specificity 94.9% (75/79) , PPV 71.4% (10/14) and NPV 93.8% (75/80) . The positive and negative PTP in intermediate 4Ts score group were 71.8% and 6.3%, while 95.2% and 34.4% in high 4Ts score group, respectively. Receiver operating characteristic (ROC) analysis manifested that LIA was preferable than PIFA, and combining the 2 assays together was significantly better than single test.@*Conclusions@#4Ts score is still an important tool for the diagnosis of HIT. Combining clinical score with heparin/PF4 antibody assay can increase the accuracy of confirming or excluding HIT. Although PIFA is inferior to LIA in the diagnostic value, its user friendliness and 100% NPV have major advantages. Combining the 2 assays together can achieve a higher diagnostic value.

Diagnostic value of two immunoassays for detecting heparin/PF4 complex antibodies in heparin-induced thrombocytopenia / 中华血液学杂志

Objectives: To assess the diagnostic values of latex immunoturbidimetric assay (LIA) and particle immunofiltration assay (PIFA) for heparin-induced thrombocytopenia (HIT) . Methods: Samples from 94 patients with suspected HIT from May 2016 to July 2018 in our hospital were prospectively analyzed by the two immunoassays. Their medical records and further follow-up data were also collected and analyzed by our hematologists to make the 4Ts scores and confirm the diagnosis of HIT, respectively. Performance characteristics of the two immunoassays were assessed, including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) . Their post-test probabilities (PTP) were also calculated based on the 4Ts score. Results: Among 94 cases, 15 (16.0%) had a positive HIT, including 6 of 37 (16.2%) with an intermediate, and 9 of 15 (60.0%) with a high 4Ts score. PIFA operating characteristics were: sensitivity 100.0% (15/15) , specificity 51.9% (41/80) , PPV 28.3% (15/53) , NPV 100.0% (41/41) . The positive PTP in intermediate and high 4Ts score group were 28.7% and 75.7%, respectively, while negative PTP were all 0. At manufacturers' cutoffs, LIA operating characteristics were: sensitivity 66.7% (10/15) , specificity 94.9% (75/79) , PPV 71.4% (10/14) and NPV 93.8% (75/80) . The positive and negative PTP in intermediate 4Ts score group were 71.8% and 6.3%, while 95.2% and 34.4% in high 4Ts score group, respectively. Receiver operating characteristic (ROC) analysis manifested that LIA was preferable than PIFA, and combining the 2 assays together was significantly better than single test. Conclusions: 4Ts score is still an important tool for the diagnosis of HIT. Combining clinical score with heparin/PF4 antibody assay can increase the accuracy of confirming or excluding HIT. Although PIFA is inferior to LIA in the diagnostic value, its user friendliness and 100% NPV have major advantages. Combining the 2 assays together can achieve a higher diagnostic value.

Methodology evaluation and Clinical significance of Procalcitonin test using Latex enhanced immunoturbidimetric assay / 国际检验医学杂志

Objective To evaluate the performance characteristic of Procalcitonin (PCT)Latex-enhanced immunoturbidimetric assay(LETIA)kit and explore its clinical application on diagnosis of sepsis.Methods The precision,recovery rate,linearity,anti-interference,correlation and clinical application of PCT kit were analyzed in this study according to standards developed by Clinical and laboratory standards institute (CLSI).Results The within-run and day-to-day run imprecision (CVs)of kit was <5.0% and<2.0% respectively at two medical diagnosis level (0.5 and 2.0μg/L).The average recovery rate was 100.6%.Linear range was from 0.05-60 μg/L,R2=0.996 as basis of determination.The test deviation was<10%,the result was obtained after repeated test of reagent kept with lid open for one month and lid closed in 37 ℃ water bath for 8 days.The test results of PCT kit using LE-TIA method were highly correlated with Roche PCT Chemiluminescence immunoassay (CLIA)kit.The PCT LETIA kit has excel-lent anti-interference performance,the serum samples containing Total Bilirubin ≤600 μmol/L,Hemoglobin ≤400 mg/dL,Triglyc-eride ≤1 000 mg/dL,Rheumatoid factor ≤200 IU/mL did not affect the testing result of the kit.The average levels of PCT in the experimental (Sepsis)group was (14.783μg/L±5.654μg/L),which in the control group was (0.237 μg/L±0.107 μg/L),there was statistically significant difference between them (P <0.05).Conclusion The PCT test using LETIA is a rapid、precise and re-liable method and it can be used for clinical diagnosis of sepsis.

Comparison of three methods for measuring C reaction protein / 国际检验医学杂志

Objective To compare the results of three methods for measuring C reaction protein.Methods 100 patients were collected from our hospital,and three different methods for measuring C reaction protein were used to analyze the level of C reaction protein.Results Correlation analysis showed that the correlation between immunoturbidimetric assay and immunochromatography was higher.The differences of three methods assayed the C reaction protein were significant (P 0.05).The differences among all of test peo-ple were significant(P <0.05).Conclusion Detection of C reaction protein was important for diagnose inflammatory diseases.

Evaluation of the Nanopia P-FDP Reagent Kit for Use in the STA-R EVOLUTION Automated Blood Coagulation Analyzer / 임상검사와정도관리

BACKGROUND: In this study on fibrinogen/fibrin degradation products (FDPs), we evaluated the performance of a quantitative immunoturbidimetric assay (ITA) using the new Nanopia P-FDP reagent kit (Sekisui Medical Co., Japan) in comparison with a semiquantitative latex agglutination assay (LA) currently performed using the FDP PLASMA kit (Diagnostica Stago SAS, France). METHODS: The quantitative Nanopia P-FDP method using the STA-R EVOLUTION automated coagulation analyzer (Diagnostica Stago SAS) was evaluated with respect to precision, linearity, carryover, and reference interval. The correlations were measured for each of the 145 samples by using the Nanopia P-FDP method and the semiquantitative FDP PLASMA method. RESULTS: The coefficients of variation with regard to precision in low and high control concentrations were 2.97% and 5.77%, respectively. The correlation coefficient of linearity (r) was 0.990 in the measurement range of 2.4-122.8 microg/mL. The level of carryover was 0.83%, while the reference interval range was 0.22-4.32 microg/mL. The results of FDP assay showed an acceptable accord in 115 samples (79%) among the 145 samples by both LA method and ITA method. Seventeen samples (12%) showed relatively lower FDP values in the LA method than those in the ITA method. Thirteen cases (9%) showed relatively higher FDP values in the LA method than those in the ITA method. CONCLUSIONS: The quantitative Nanopia P-FDP method showed good precision, linearity, carryover, reference interval, and an acceptable concordance rate with the semiquantitative FDP PLASMA method. Thus, the Nanopia P-FDP reagent using the STA-R EVOLUTION automated coagulation analyzer can replace the FDP PLASMA reagent for the quantitative analysis of FDPs.

Microalbuminuria analysis in Thai patients with diabetes and hypertension using albumin blue 580 fluorescence assay.

Objective: To evaluate the performance of the fluorescence assay using albumin blue 580 for microalbuminuria, which is one of the early signs of renal diseases and an important cardiovascular risk factor for patients with diabetes and hypertension. Methods: The fluorescence assay was tested for its precision and reliability by determining the intraassay and interassay coefficients of variation (CV). The correlation of the assay with the standard immunoturbidimetric assay (DCA 2000ฎ microalbumin/creatinine reagent kit), which is one of the methods routinely used for microalbuminuria, was evaluated by quantitating the urinary albumin levels in 13 urine samples by both methods and the results were compared. The fluorescence assay was also used to detect the presence of microalbuminuria in 11 healthy subject, 11 patients with hypertension, and 10 patients with diabetes and hypertension. Results: At the albumin concentrations of 5, 50, and 150 mg/L, the intraassay CVs of the fluorescence assay were 7.9, 4.4, and 3.5%, while the interassay CVs were 4.1, 8.0, and 0.4%, respectively. The fluorescence assay also showed a very good correlation with the standard immunoturbidimetric assay, with the intraclass correlation coefficient of 0.94 (0.81 to 0.98 at 95% confidence interval). When the assay was used to detect the presence of microalbuminuria (the excretion of 30-300 ตg albumin/mg creatinine), it identified two out of 11 patients with hypertension (18%) and three out of 10 patients with both diabetes and hypertension (30%) having microalbuminuria whereas none of the healthy subjects had the condition. In addition, the presence of clinical albuminuria (the excretion of more than 300 ตg albumin/mg creatinine) could also be identified in three patients with hypertension (27%) and one patient with both diabetes and hypertension (10%) respectively. Conclusion: The fluorescence assay using albumin blue 580 was found to be precise and reliable and also showed a very good correlation with the standard immunoturbidimetric assay. In addition, the fluorescence assay is simple and the assay cost is much cheaper compared with the immunoturbidimetric measurement. Therefore, it could be another alternative method for microalbuminuria, particularly for most hypertensive or diabetic patients in Thailand, who can benefit from the detection of microalbuminuria but cannot afford regular tests.

Perfunnance evaluation on a latex enhanced immunoturbidimetric?_2-microglobulin kit / 中国基层医药

Objective To evaluate the performance of a latex enhanced immunoturbidimetric?2-microglobulin kit in clinical use. Methods The lower limit of detection,precision,accuracy and linearity range was determined on the automatic chemistry analyzer Hitachi 7170S. Results The lower limit of detection was 0. 09mg/L. The within-run precision was less than 4% while the between-run precision was less than 8%. The accuracy was 99.29 % and the linearity range was 0.2～18mg/L. Conclusion The?2-microgiobulin kit shows good performance in clinical use.