Performance evaluation of the hook effect of five immunoturbidimetric kits for the detection of specific proteins / 国际检验医学杂志

Objective To evaluate the performance of hook effect of five immunoturbidimetric kits for the detection of specific proteins on biochemical analyzers.Methods Five immunoturbidimetric kits with higher market share that came from Beijing BSBE (A), Sichuan maccura (B), Shenzhen Mindray (C), Ningbo Medical System (D) and Beijing Leadman (E) were used to determine six specific proteins.A series of concentration gradient samples were prepared and tested to compare the performance of hook effect from different manufactures′kits when the analytical measurement ranges were known.Results In the five kits, the upper limits of the safe range of antigen excess about ASO, hs-CRP andβ2-MG were relatively higher in B and C.No hook effect occurred at the approximate concentration of 10 000IU/mL, 1 000mg/L and 226mg/L respectively.The highest upper limits for CysC were C and E kits, and both were greater than 112mg/L.The upper limits of the safety range for other manufacturers were more than 700mg/L about RBP except for D.The maximum upper limit of mALB was D.Hook effect did not appear at the concentration of 43 560mg/L approximately.Conclusion Different manufactures′immunoturbidimetric kits have different hook effect performance.The laboratories should verify the hook effect performance before using the kits, and select the most suitable kit to prevent hook effect.

Analytical Performance of INNOVANCE Free Protein S Antigen on Sysmex CS-5100

BACKGROUND: Protein S deficiency is a common cause of thrombophilia. Free protein S has been suggested as one of the best screening tests for this deficiency. We evaluated an immunoturbidimetric free protein S reagent, INNOVANCE Free Protein S Antigen (Free PS Ag; Siemens Healthcare Diagnostics, Germany), using a CS-5100 coagulation analyzer (Sysmex, Japan). METHODS: The performance of INNOVANCE Free PS Ag was evaluated according to the CLSI guidelines. Precision, linearity, and verification of reference intervals were examined. The INNOVANCE Free PS Ag was also compared by the STA-Liatest Free Protein S immunoturbidimetric assay (Diagnostica Stago, France). RESULTS: The repeatability and within-laboratory imprecision of INNOVANCE Free PS Ag were 0.8% CV and 2.0% CV at the normal level, and 1.3% CV and 2.3% CV at the abnormally low level, respectively. This assay showed linearity from 4.0% to 151.9% (correlation coefficient r=1, P < 0.0001). Reference intervals for males and females were verified as acceptable. INNOVANCE Free PS Ag was comparable with STA-Liatest Free Protein S with a very high correlation (r=0.935, P < 0.0001). The results for the INNOVANCE antigen were higher. CONCLUSIONS: The INNOVANCE Free PS Ag on a Sysmex CS-5100 coagulation analyzer has excellent analytical performance and is comparable with the STA-Liatest Free Protein S assay.

Performance Verification of LP(a)Reagents in Clinical Laboratory / 现代检验医学杂志

Objective To validate the analytical performance of four LP(a)reagents with Immunoturbidimetry method used on the automatic biochemistry analyzer for preliminary clinical application.Methods The performance of four LP(a)reagents (labeled as A,B,C,D)with method from RANDOX,Zhejiang Kuake Co.,Beijing Leadman Co.and Beijing Jiuqiang Co.on Olympus AU5800 automatic biochemistry analyzer were assessed.The precision,linearity range,accuracy,disturbance (vita-min C,bilirubin,hemoglobin,TG)were assessed.Results The within-run CVs of the four reagents (A,B,C and D)were 0.64%~1.18%,3.59%~4.75%,1.33%~3.05% and 1.43%~2.01% respectively.The between-run CVs in A,B,C and D were 1.04%~1.7%,3.81%~4.93%,2.16%~4.76% and 2.33%~3.21% respectively,lower than the stated.The lin-earity range was 82~923 mg/L (r2 =0.997),130~935 mg/L (r 2 =0.996 4),120~1025 mg/L (r 2 =0.992 1)and 117~943 mg/L (r2 =0.999 5)in the four reagents,which demonstrated a sound linear correlation.For interference tests,no re-markable interferences (<±10%)of reagent A and reagent D were detected when Vitamin C≤10 mg/dl,hemoglobin≤200 mg/dl,bilirubin≤40 mg/dl and TG≤500 mg/dl.Interference of reagent B was found when VC≥5 mg/dl,TG≥250 mg/dl and when TG≥250 mg/dl reagent C was interfered significantly.The four LP(a)reagents were used to detect the lipid con-trol,and the deviations of the target value were - 8.07%,1.34%,- 8.05% and 7.38% respectively.Conclusion When used in automatic biochemical analyzer,the four LP(a)reagents showed high precision.The four reagents are all able to meet clinical test requirements,nevertheless,anti-interference capability were different.

The clinical application to detect the anti cyclic citrullinated peptide antibody by immune Turbidimetry / 国际检验医学杂志

Objective To evaluate the clinical application value of anti cyclic citrullinated peptide antibody(CCP) by immune tur‐bidity method for the the diagnosis of rheumatoid arthritis (RA) .Methods The serum of 195 cases of RA patients ,105 cases of os‐teoarthritis ,52 cases of osteoporosis ,42 cases of connective tissue ,40 patients with systemic lupus erythematosus ,305 cases of pa‐tients with other diseases and 90 cases of healthy controls were collected ,the CCP were detected by latex CMIA and ELISA . Results The CCP positive were 141 cases in RA(72 .30% ) ,54 cases(51 .42% ) in arthritis ,15 cases in osteoporosis (28 .84% ) ,15 cases in connective tissue(35 .71% ) ,18 cases (45 .0% ) in systemic lupus erythematosus (SLE) ,11 cases (3 .60% ) in other disea‐ses .There were negative in 90 cases of healthy controls .The variation coefficient was 1 .9% -2 .0% ,and the total coefficient of var‐iation was 2 .0% -2 .1% .The linear range of Latex method was divided into 0 .8-100 U/mL .There were no diffrence in the sensi‐tivity and specificity of detection to CCP by CMIA ,ELISA and Latex .Conclusion The sensitivity and specificity of detection to CCP by Latex was good ,and there was wide linear range .

Establishment of Pepsinogen Reference Range and Its Clinical Application in Shanghai Area / 现代检验医学杂志

Objective To establish serum pepsinogen (PG)reference range healthy crowd with latex-enhanced immunoturbi-dimetry of and explore its clinical application in stomach disease in Shanghai area.Methods Selected randomly 8 763 healthy adults who livied in Shanghai for more than 10 years and 269 patients with different stomach trouble confirmed by gastro-scope and pathology.By latex-enhanced immunoturbidimetry to detect the serum pepsinogen Ⅰ (PGⅠ)and pepsinogen Ⅱ(PGⅡ).Results The serum PGⅠ,PGⅡand PGⅠ/PGⅡlevel showed a skew distribution.The normal reference range was 24.6~98.97 ng/ml,≤21.7 ng/ml and ≥3.43.PGⅠand PGR values decreased significantly in both atrophic gastritis (PGⅠ=36.6 ng/ml,P=0.007,PGR=3.63,P<0.001)and gastric cancer groups(PGⅠ=20.6 ng/ml,PGR=3.2,P<0.001).PGⅠand PGⅡvalues increased significantly in digestive ulcer group(PGⅠ=83.6 ng/ml,PGⅡ=17.5 ng/ml,P<0.001),but PGR values decreased significantly (PGR=4.37,P=0.006).Conclusion Establishing serum pepsinogen refer-ence range of healthy crowd with latex-enhanced immunoturbidimetry in the Shanghai area can help to diagnose better the stomach trouble.

The prevention of the hook effect in the automatic biochemistry analyzer by the immune ratio turbidity method / 国际检验医学杂志

Objective To understand correctly the hook like effect of the immune transmission and transmission turbidity in the automatic biochemical analyzer and the prevention of the hook like effect .Methods First ,it had the function set of measurement linear range of the upper limit of the instrument and the instrument automatic dilution redo ,and then ,had determination of excee‐ding the upper limit of measurement range and artificial dilution before the sample setting .Results The group average value was 2 .49 g/Lbefore the determination setting ,3 .31 g/L after the determination setting ,and 3 .33 g/L artificial dilution determination . Conclusion High dose hook effect makes the strong positive to weak positive samples of measurement by error ,even false negative results ,and high concentration sample makes low value .So the set of samples and dilution to determination of instrument ,measured values are more close to the true value .

Self-prepared quality control product for urinary retinal-binding protein and its performance evaluation / 国际检验医学杂志

Objective To investigate the preparation of the internal quality controls for urinary retinal binding protein(RBP)de-tected by the latex enhanced immunoturbidimetry assay and its performance evaluation.Methods The urine specimens from the pa-tients with nephropathy and healthy people with physical examination were collected,centrifuged by 3 500 r/min for removing sedi-ment,urinary RBP levels were adjusted to the low value for healthy population and the high value for the patients with nephropa-thy;then conducted the anticorrosion,packed and stored at -20 ℃.By using the urinary RBP commodity kits,the latex enhanced immunoturbidimetry was adopted to detect urinary RBP,the intra-batch and inter-batch precisions were detected respectively.Then the high and low values of self-prepared controls were detected once per day for consecutive 5 months.The data were processed by using the SPSS13.0 software.Then the performance of self-prepared urinary RBP quality control was evaluated.Results The intra-batch imprecision of 2 levels of urinary RBP controls was less than 5% and the inter-batch imprecision was less than 6%;the stable period by storage at -20 ℃ was at least 5 months,the imprecision had no statistical difference within 5 months(P >0.05).Conclu-sion The high and low levels of self-prepared urinary RBP quality controls can meet the operating requirements of internal quality controls.

Evaluation of Analytical Measurement Ranges of Three Full Range C-Reactive Protein Tests Using Immunoturbidimetric Assay / 대한진단검사의학회지

BACKGROUND: Recently developed full-range C-reactive protein (CRP) tests, which are based on the immunoturbidimetric method, have wider analytical measurement ranges (AMR) than previously used tests. We evaluated the AMR of 3 full-range CRP tests-2 new and 1 previously used test. METHODS: We analyzed the precision and AMR of 2 full-range CRP tests (Sekisui, Nanopia CRP, N-CRP and Iatron, IATRO CRP-EX, I-CRP) and compared the values obtained for these tests with those obtained for the conventional full-range CRP test (Sekisui, PureAuto S CRP, P-CRP). We evaluated the tests for the limit of quantification and for linearity. We also compared these results of these tests by using the comparative test (Dade Behring, cCRP) for cardiovascular risk assessment. RESULTS: Coefficients of variation (CVs) of all the full-range CRP tests were less than 10% for concentrations greater than 0.6 mg/L, and CVs of N-CRP and I-CRP were lower than those of P-CRP for concentrations less than 1 mg/L. N-CRP (0.1-467 mg/L) and I-CRP (0.1-280 mg/L) had wider AMR than P-CRP (3-233 mg/L). All the full-range CRP tests showed more than 90% agreement with the cCRP values for the assessment of cardiovascular risk. CONCLUSIONS: The 3 full-range CRP tests, by virtue of their wide AMR, may be used for the detection of acute inflammation as well as for the assessment of cardiovascular risk. N-CRP and I-CRP may be more useful than P-CRP for determining the CRP concentration, especially for the detection of concentrations close to the lower or upper limit of the analytical range, without the need for repetition of the test.

Performance Evaluation of HbA1c Test on the Toshiba 200FR NEO Using AutoLab HbA1c Reagent / 임상검사와정도관리

BACKGROUND: Hemoglobin A1c (HbA1c) is widely used for the monitoring of glycemic control in diabetes mellitus patients. Various methods are applied for the determination of HbA1c levels. Recently, a novel National Glycohemoglobin Standardization Program (NGSP)-certificated reagent (AutoLab HbA1c, IVD-LAB, Korea) was introduced for use in an automated chemistry analyzer. We evaluated the analytical performance of this immunoturbidimetry reagent and compared it with the ion-exchange high performance liquid chromatography (Variant II Turbo, Bio-Rad Laboratories, Inc., USA) and immunoassay (Cobas Integra 800, Roche Diagnostics, Germany) methods. METHODS: Toshiba 200FR NEO (Toshiba Medical Systems Co., Japan) with the AutoLab reagent was evaluated for precision, linearity, carryover and compared with Cobas Integra and Variant II Turbo. RESULTS: Coefficients of variation (CVs) of within-run imprecision for low and high level were 1.8% and 0.7%, respectively. CVs of within-laboratory imprecision for low and high level were 2.4% and 1.0%, respectively. The linearity was excellent with R2 = 0.99 in the range of 3.05-15.50%. It was well correlated with Variant II Turbo (R=0.9904) and Cobas Integra 800 (R=0.9992). The carryover rate was 0.4%. CONCLUSIONS: The Toshiba 200FR NEO with the AutoLab reagent showed excellent precision and linearity and minimal carryover rate. It was well correlated with the other widely used methodological instruments. It may be used for the diagnosis and the treatment monitoring of diabetes.

Construction of an antibody microarray based on direct labeling strategy for microalbuminuria measurement / 中华肾脏病杂志

Objective To build an antibody microarray based on direct labeling strategy for microalbnrninuria measurement, and evaluate it's technical potentiality for clinical application. Methods Urine samples of diabetic patients were collected. Antibody microarrays were constructed by preparation of array support, array fabrication, then protein assay and data analysis were performed. Procedure conditions for each step especially the labeling of samples were optimized. The set-ups were evaluated in terms of sensitivity, specificity and reproducibility. Urinary albumin excretion in the samples was detected by fabricated protein array, which was compared to that detected with immunoturbidimetry. Results The signal intensity was best when protein quality ratio of pure albumin or urine sample against NHS-biotin was 2:1. A calibration curve with a correlation coefficient of 0.9995 was established. The lower limit of detection was 0.0617 mg/L. Interehip and intrachip variation studies conducted on patient urine demonstrated CVs as 6.78%-9.22% and 3.35%-7.59%, respectively. Compared with the immunoturbidimetry, the antibody microarray was able to detect the extremely lower grade albumin in urine samples. The correlation coefficient of the results obtained by the two methods was 0.9199 (P <0.01). Conclusion An antibody microarray based on direct labeling strategy for microalbuminuria measurement is successfully established, which is comparable to immunoturbidimctry in its accuracy and will have great potential for clinical use with its high throughput, sensitivity, specifity and reproducibility.

Evaluation the Results of C-reaction Protein Tested by Specific Protein Gold Measuring Instrument / 医学研究杂志

0.05).Conclusions Special protein gold measuring instrument had high sensitivity,good accuration and speediness,which was suitable for clinical LAB to test CRP.

Levels of Serum Apolipoprotein in the Middle Aged of Qingdao City / 中国慢性病预防与控制

Objective To study the levels of serum apolipoproteins in the middle aged in Qingdao city.Methods 2 287 subjects(male 1 631,female 656) aged 35～59(44.70?5.99) yrs in Qingdao city were randomly recruited.Their serum Apolipoprotein B(ApoB) and Apolipoprotein E(ApoE) were measured by immunoturbidimetry assay.Results The results of ApoAI,ApoB,ApoE and ApoB/AI were(1.36?0.22)g/L,(0.99?0.26)g/L,(4.89?1.83)mg/dl and 0.75?0.23,respectively.The abnormal ratios of Apo AI,Apo B,Apo E and ApoB/AI were 12.77%,29.03%,28.82% and 6.56%,respectively.With the partial correlation analysis adjusted by age,sex and BMI,the cardiovascular risk factors score were positively related with the level of Apo AI,and negatively related with ApoB,ApoE and ApoB/AI.Conclusion There was a close relationship of cardiovascular risk factors score with serum ApoB/AI,ApoB and ApoE.