[Decrease in number of venipuncture tubes enables us to shorten turnaround times of blood-based testing in clinical laboratories].

We are making efforts to reduce the number of venipuncture tubes for blood-based testing. On the reconstruction of hematology system in 2011, we planned the system to include hemoglobin A1c (HbA1c) assay and to replace the assay instrument for erythrocyte sedimentation rate (ESR) to use EDTA-2K based whole blood. Accordingly, the revised system required a single test tube for hematological testing, resulting in reduction of blood volume collected. It was estimated that the whole blood collected from outpatients in a year decreased from 143 L to 109 L. Also, the times required to complete venipuncture after outpatient accession were significantly shortened to 10(0.71 +/- 0.27) (2.75-9.55) min, and nearly 50% of outpatients experienced < 2 min of waiting. As the times required for venipuncture were shortened, the turnaround times (TATs) from outpatient accession to finally reporting the test results to physicians were also shortened in the blood-based laboratories. The TATs after outpatient accession to reporting the test results in biochemistry and serology ranged 59 to 80 min (90%-tile), indicating 8 to 16 min less when compared with those before system reconstruction. In conclusion, the decrease in number of venipuncture tubes in hematological testing enables us to reduce the blood volume collected, and to shorten (1) times required for venipuncture procedure, (2) waiting times, and (3) TATs for blood-based testing. However, as demonstrated in HbA1c, i.e., a 50%-tile of TAT for HbA1c delayed for 5 min, the configuration of assay system can greatly influence the TATs of individual test parameters.

[Laboratory-based evaluation of "INOVA/QUANTA Lite" to determine antinuclear antibodies (ANA) and autoantibodies to double-stranded DNA, SS-A and SS-B].

We evaluated QUANTA Lite reagent series (INOVA Diagnostics, CA, USA) to determine antinuclear antibodies (ANA) and autoantibodies to double-stranded (ds) DNA, SS-A and SS-B, in parallel with MESACUP (Medical & Biological Laboratories, Nagoya). Overall agreements between two reagents for qualitative interpretation ranged from 77.5% (ANA) to 99.0%(anti-SS-B antibodies). When we compared to the results by indirect fluorescent antibody (IFA) test on HEp-2 cells, QUANTA Lite ANA demonstrated better sensitivity and specificity; 92.2% versus 76.5% in sensitivity and 92.1% versus 86.8% in specificity. Also, determining anti-chromatin antibodies and IFA test onto Chrithidia luciliae demonstrated greater interpretive correlation to detect anti-ds DNA by QUANTA Lite than by MESACUP. All the discrepant sera to which QUANTA Lite SS-A gave positive interpretations were confirmed to contain the antibodies specific to SS-A 52kDa antigen, which is supplemented to QUANTA Lite capture-probes. With these results, we can conclude that QUANTA Lite has superiorities over MESACUP; (1) to detect a variety of autoantibodies consisting of ANA, (2) to have a better correlation with confirmatory tests to detect anti-ds DNA antibodies, (3)to detect additional autoantibodies specific to SS-A 52kDa antigen, and (4) to have an enough compatibility in determining anti-SS-B antibodies.

[Evaluation of turnaround time (TAT) for outpatients from venipuncture accession to reporting test results of blood chemistry and blood cell analysis to physicians].

In response to the revision of social medical insurance policy, in which hospital clinics can additionally charge for laboratory testing when the test results are presented to an outpatient in a print-out form on a visiting day, we evaluated laboratory-spending times, so-called turnaround times (TATs). A total of 14,802 outpatients during the period from October 2010 to May 2011 were enrolled. TATs from venipuncture accession to completing blood collection revealed a log-normal distribution with 5 to 6 min of mode and 10(0.95 +/- 0.26) (4.90 to 16.2) min of mean +/- standard deviation. Order waiting time figured a half-normal distribution, 50% tile and 90%-tile being 4 and 16 min, respectively. TATs of blood collection and order waiting time were significantly influenced by days of the week and accession time. Through analysis of TATs from specimen receipt to reporting test results, it became apparent that the tests determined by immunoassay and erythrocyte sedimentation rate (ESR) required more minutes when compared to the remaining tests. Total TATs from venipuncture accession to reporting test results ranged 28 to 29 min (50%-tile) for complete blood count and hemoglobin A1c, whereas those of endocrinology and tumor markers were 65 to 73 min. In conclusion, the tests determined by immunoassay are rate-limiting for rapid reporting efforts in clinical laboratories. Secondly, TATs of blood collection are mostly influenced by order waiting time depending on days of the week and accession time. At present, there is no target value for TATs, however it is important to recognize the necessity to shorten laboratory-spending TATs.

[Quantitative estimation of preanalytical variables which may influence the determinations of prothrombin time (PT) and activated partial thromboplastin time (APTT)].

Prothrombin time (PT) and activated partial thromboplastin time (APTT) tests principally measure the time for a fibrin clot developed in citrated plasma after activation. For the complexity of chemical reactions, a number of preanalytical variables potentially influence the outcome of results. In the present study, we evaluated some preanalytical variables frequently encountered in clinical settings. The volumes of citrated whole-blood specimens collected from inpatients widely varied from 0.99 ml to 2.90 ml indicating 1.6% of unacceptable rate, whereas none of the specimens from outpatients was out of acceptable range. The citrated whole-blood volume significantly affected the determinations of both PT and APTT; the results indicating the more volume the longer clotting time. Also, whole-blood specimens collected in EDTA2K revealed significantly prolonged PT and APTT values in healthy subjects and the patients with anticoagulant therapy of heparin and of warfarin. Storage conditions, time and temperature might influence the PT and APTT values. In particular, citrated whole-blood specimens stood at room temperature revealed the prolonged clotting time in APTT assay by hours. The effects of other variables evaluated such as a half-volume adjustment, needle gauge or syringe type were negligible. With these results, it was concluded that; first, an accurate venipuncture is critical, particularly venipuncture from patients in wards where many different physicians and nurses are in charge and in changing by days. Secondly, the citrated whole-blood specimens should be assayed quickly without any unnecessary storage at room temperature beyond four hours.

[Multisite-based approach to assure inter-assay system compatibility among different exclusive-typed immunoassay systems through determining exchanged calibrators].

It is well known that most exclusive-typed immunoassay systems are highly precise but are poor in compatibility of their determinations. Thus, it is difficult to compare the determinations among different systems, posing problems when a patient is transferred to different hospitals or when a laboratory intends to change the system currently used. In the study, we tried to approach how to assure inter-immunoassay compatibility among four different systems through determination of the exchanged calibrators. First, determinations of total protein and albumin, and electrophoretic fractionation demonstrated marked differences among calibrators in their protein constituent. Some calibrators were prepared with human sera, but others were with inorganic or non-human albumin-based solution. Regression analysis of calibrators between the indicated concentrations by manufacturers and those actually determined by the different immunoassay systems revealed that; most slopes were closed to 1.0 for alpha-fetoprotein and prostate-specific antigen, but widely dissociated from 0.28 to 4.71 for CA19-9. In evaluation of clinical serum samples, determinations by one immunoassay system were compared with those converted based on a linear regression equation that was obtained by determination of the exchanged calibrators. However, this procedure could not improve compatibility, and positive effects of conversion varied by immunoassay systems combined, and also by test parameters. With these, we concluded that simple conversion of determinations by using the exchanged calibrators and a statistical linear regression could not provide us with the expected compatibility. Thus, standardization of target molecules or probes, and of calibrator constituent were urgent issue to assure inter-immunoassay compatibility.