Effective leukocyte removal from platelet preparations by centrifugation in a new pooling bag

A pooling bag (Leukotrap, Cutter Laboratories, Berkeley, CA) with a protruding pocket at the bottom into which heavier cellular elements are collected after centrifugation at 390 X g for 10 minutes, was studied. The tab is clamped before transfusion. Varying numbers of platelet concentrates (PC) that had been stored for different durations were pooled and centrifuged in the bags. When 4 or more units of PC were studied, the results were independent of the number of units and the duration of storage. Approximately 90 percent of the contaminating leukocytes (WBC) were removed with a platelet loss of less than 10 percent. Similar results were obtained with single-donor platelets (WBCs decreased 93%; range, 77-99%; n = 12). Posttransfusion increments were similar to those with unmodified platelets; in four patients, febrile platelet transfusion reactions were eliminated by the WBC removal. Thus, the bags represent a simple, reproducible, and effective means of reducing WBC and red cell contamination of platelet preparations with acceptable platelet losses.     

Evaluation of the automated leukocyte differential count in emergency department patients

This study compares the results of the leukocyte three-part differential count as determined by the Coulter S-Plus IV in 104 consecutive patient samples from the emergency department with results obtained by conventional visual differential. A high rate (40%) of instrument rejection was found, reflecting the high prevalence of disease and hematologic abnormalities in the patient population. No clinically significant abnormality went undetected, demonstrating that the automated leukocyte three-part differential is effective as a screening test in the emergency department patient population.     

迈瑞BC-5500全自动血液分析仪的白细胞分类应用评价

目的对国产仪器BC-5500全自动血液分析仪进行系统评价,了解国产血液分析仪的白细胞（WBC）分类性能。方法参照国际血液学标准化委员会（ICSH）和美国临床实验室标准化委员会（NCCLS）制定的评价标准对BC-5500的各项性能进行评估。结果BC-5500血液分析仪的总重复性、批内、批间CV值为0．27％-2．85％,天间CV值为0．57％-2．93％;BC-5500各项指标线性良好（r〉0．998）;携带污染率低,各参数都接近0％;相关性实验表明BC．5500与雅培CELL-DYN3700血液分析仪测定结果密切相关;WBC分类实验表明BC-5500与手工分类结果比较,二者中性粒细胞、淋巴细胞、单核细胞、嗜酸性粒细胞及嗜碱性粒细胞的r值分别为0．9680、0．9426、0．6465、0．8207和0．2876。在异常细胞识别方面,BC-5500能够对t72例临床标本中明显的异常细胞进行提示,但提示结果出现较高假阳性,提示信息也比较简单,个别异常标本出现假阴性。与CELL-DYN3700旗标提示相比．BC-5500漏检率稍高。结论BC-5500各方面性能良好,但在异常细胞提示上还需进一步改进。由于它是我国第一台拥有自主知识产权的全自动五分类血液分析仪,并有自己的配套试剂及质量溯源体系,因而具有理想的发展应用前景,是一款能够对大批量全血标本的血细胞计数与WBC分类进行快速而有效筛检的全自动血液分析仪。     

迈瑞BC-5500全自动血液分析仪的白细胞分类应用评价

目的对国产仪器BC-5500全自动血液分析仪进行系统评价,了解国产血液分析仪的白细胞(WBC)分类性能。方法参照国际血液学标准化委员会(ICSH)和美国临床实验室标准化委员会(NCCLS)制定的评价标准对BC-5500的各项性能进行评估。结果BC-5500血液分析仪的总重复性、批内、批间CV值为0.27%~2.85%,天间CV值为0.57%~2.93%;BC-5500各项指标线性良好(r>0.998);携带污染率低,各参数都接近0%;相关性实验表明BC-5500与雅培CELL-DYN 3700血液分析仪测定结果密切相关;WBC分类实验表明BC-5500与手工分类结果比较,二者中性粒细胞、淋巴细胞、单核细胞、嗜酸性粒细胞及嗜碱性粒细胞的r值分别为0.9680、0.9426、0.6465、0.8207和0.2876。在异常细胞识别方面,BC-5500能够对172例临床标本中明显的异常细胞进行提示,但提示结果出现较高假阳性,提示信息也比较简单,个别异常标本出现假阴性。与CELL-DYN 3700旗标提示相比,BC-5500漏检率稍高。结论BC-5500各方面性能良好,但在异常细胞提示上还需进一步改进。由于它是我国第...     

基于PCR的基因定量方法及方法学评价

基因定量检测已经成为研究遗传性疾病、感染性疾病以及某些易感基因引起的疾病的重要手段.在过去的几年中已相继出现了一些高效自动的技术方法.目前可用的基因定量方法大致可以分成3类:DNA印迹技术(Southern杂交),细胞遗传学方法和以PCR扩增为基础的基因定量方法.本文对基于PCR的基因定量方法作一综述,并进行方法学评价...     

The use of programmed microcalculators for automation of leukocyte count

Soviet programmed microcalculators are recommended to be used for the calculation of the leukocytic formulae when making serial blood analyses at clinical laboratories. The suggested program helps completely automate the process of estimating the leukocyte types, detectable in microscopic examination of the blood smears; the results may be obtained as a per cent ratio of the cells (a form most prevalent nowadays) and as their quantity per microliter of blood. The presence of service elements in the program essentially simplifies the work, making it convenient for an untrained user of the microcalculator. Since commercial Soviet programmed microcalculators somewhat differ in the systems of program steps, two variants of the program are suggested, adapted to the two most prevalent designs.     

新等位基因HLA-B*4060的认定

应用PCR—SSO基因分型技术发现可能的HLA新等位基因，对PCR产物进行测序及克隆测序，确认与最同源HLA等位基因序列的差异。发现一个样本的HLA—B位点结果异常，其核苷酸序列与已知所有HLA—B位点等位基因序列均不一致，与同源性最高的等位基因B＊400102在第三外显子区域有7个碱基的差异。判断该等位基因为HLA-B位点的一个新等位基因，于2005年7月被WHOHLA因子命名委员会正式命名为HLA-B＊4060。     

Evaluation of a novel commercial rapid test for dengue diagnosis based on specific IgA detection

The performance of the novel commercial test ASSURE® Dengue IgA Rapid test (MP Diagnostics) was evaluated using a panel of 172 sera collected from dengue patients and 47 sera from healthy blood donors. The overall specificity and sensitivity were 85.1% and 61.0%, respectively. However, the positivity rate for IgA went from 33.3% for sera collected the same day of fever onset to 81.2% for sera collected 5 days after fever onset. Infections with serotype 2 viruses were detected more efficiently than those with serotype 1 viruses, and no sera from infections with serotypes 3 and 4 were available. In addition, the kit was twice more efficient at detecting secondary infections than at detecting primary infections. Finally, the ASSURE® test showed good repeatability and reproducibility. The results of this study suggest that the ASSURE® Dengue IgA Rapid test may become a useful and easy-to-use test for early dengue diagnosis.     

Human platelet antigen allele frequencies and new mutations on platelet glycoprotein genes in the Chinese Han population

Background and Objectives: The frequencies of human platelet antigens (HPAs) vary between different populations. In this study, we determined the HPA allele frequencies in the Chinese Han population and identified situation of incompatibility possibly leading to alloimmunisation. Methods: A total of 750 volunteer blood donors of the Chinese Han population were genotyped for HPA‐1 to ‐17w systems. HPA genotyping was determined by polymerase chain reaction sequence‐based typing. Results: Among the 17 HPA systems, the allele frequency is different from other populations. We noted the absence of HPA‐7bw to HPA‐14bw, HPA‐16bw and HPA‐17bw alleles in the population. The estimated incompatibility probabilities regarding platelet antigens 1 to 6w and 15 systems after transfusion of random donor platelet were from 0·004 to 0·373. Thirteen glycoprotein alleles were observed in the population. In addition, we identified 16 novel mutations on the glycoprotein genes separated from HPA polymorphisms, including GP1BA (517‐525delAAC), ITGA2B (2722C>T and IVS26+85T>C), ITGA2 (1521C>T, 2474T>G and IVS20+10 G>C), ITGB3 (1476G>A, IVS10+19C>A, 1813G>A, IVS11+21G>A, IVS11+152A>G and IVS11‐104T>C), GP1BB (IVS1‐79G>A, IVS1‐27C>T and 129G>A) and CD109 (2139A>G). Five of them could lead to amino acid deletion, substitution or premature stop codon in corresponding glycoprotein. Conclusions: There was a high degree of polymorphism of the membrane glycoprotein genes related to human platelet alloantigen‐1 to ‐17w systems in the Chinese Han population. These data could have some impact on the diagnosis, prevention and treatment of alloimmune thrombocytopenia.     

Evaluation of a rapid whole blood ELISA for quantification of troponin I in patients with acute chest pain.

BACKGROUND: Troponin I (cTnI) provides important prognostic information in patients with chest pain. We wished to evaluate a rapid, whole-blood analyzer for quantitative point-of-care testing. METHODS: A quantitative point-of-care test system (Stratus CS((R)); Dade-Behring) for cTnI with an incorporated centrifuge was evaluated in 412 patients with chest pain less than 12 h. RESULTS: Results were available within 15 min. CVs were 4.5% at 0.1 microgram/L, 4.2% at 0.25 microgram/L, and 6.5% at 0.82 microgram/L. The detection limit was 0. 01 microgram/L. The 97.5% percentile in a healthy population was 0.08 microgram/L. Based on ROC curve analysis, a threshold of 0.15 microgram/L was calculated for the detection of acute myocardial infarction (AMI). With it, sensitivity for the detection of patients with AMI (n = 62) was 63% at arrival and 98% after 4 h (Stratus II((R)), 48% and 85%, respectively; P <0.01). In 42% of patients with unstable angina (n = 121), cTnI was >/=0.08 microgram/L (Stratus II, 28%; P <0. 01). During 30 days, death or AMI occurred in 25.5% of these cTnI-positive vs 2.9% of cTnI-negative patients (Stratus II, 29.4% vs 5.8%). CONCLUSION: The Stratus CS provided better analytical performance and comparable or better prognostic information than the Stratus II.     

新等位基因HLA-B^＊5812的认定

应用流式反向PCR-SSO和PCR-SSP基因分型技术发现可能的HLA新等位基因,对PCR产物进行HLA基因分型、DNA序列分析及克隆测序。发现一个样本的HLA-B位点结果异常,其核苷酸序列与已知所有HLA-B位点等位基因序列均不一致,与同源性最高的等位基因B*5801的差异在于第2外显子区域中的第69位碱基发生了G→T的替换,即"GCA→TCA",结果改变了第24位密码子编码的氨基酸,即"丙氨酸→丝氨酸"。判断该等位基因为HLA-B位点的一个新等位基因,已于2006年4月被WHOHLA因子命名委员会正式命名为HLA-B*5812。     

Evaluation of a new, rapid lactate analyzer in critical care

Objective: To determine the reliability, precision and clinical usefulness of a newly developed substrate-specific lactate/blood gas analyzer (Chiron M865). Setting: A university hospital 31-bed mixed medical/surgical intensive care unit (ICU). Patients: Seventeen critically ill patients with sepsis (n = 4), post-cardiac surgery (n = 8), hepatic failure (n = 2) or acute respiratory failure (n = 3). Measurements and results: Lactate levels were measured in 17 critically ill patients on whole blood using the new Chiron M865, and on plasma by a stat lactate/glucose analyzer (Yellow Spring Instrument, YSI mode 2300) and a reference lactate/glucose/electrolyte/enzyme analyzer (Hitachi 911). The influences of temperature and storage on blood lactate levels were then evaluated. Mean lactate values obtained were 3.73 ± 2.84 mmol/l with the Chiron, 3.03 ± 2.60 mmol/l with the YSI, and 3.59 ± 2.92 mmol/l with the Hitachi. There was a strong correlation between the three analyzers (Chiron vs YSI r = 0.99; Chiron vs Hitachi 911 r = 0.98), and good agreement between the Chiron and the two other methods (Chiron/YSI bias was –0.65, SD 0.50 mmol/l; Chiron/Hitachi bias was 0.12, SD 0.55 mmol/l). The variability coefficients were 3.7 % for the Chiron and 3.0 % for the YSI. During short term storage, a continuous increase in lactate levels was observed at room temperature (2.36 ± 1.68 mmol/l to 2.53 ± 1.74 mmol/l, p < 0.05), but when the samples were kept on ice there was just a small statistically significant, but not clinically significant, increase after 8 min (2.37 ± 1.62 mmol/l to 2.39 ± 1.63 mmol/l, p < 0.05). For longer storage times, samples on ice showed a small increase in lactate levels after 15 min (3.73 ± 2.90 mmol/l to 4.01 ± 3.00 mmol/l, p < 0.05) but no further increase during the subsequent 45 min. Conclusions: The new Chiron lactate analyzer is reliable for serial whole blood lactate measurements in an intensive care stat laboratory. Samples should be kept on ice immediately after sampling to minimize in vitro erythrocyte production of lactate. Received: 25 September 1998 Final revision received: 4 January 1999 Accepted: 3 February 1999     

Evaluation of a new commercial assay kit for quantification of lactate dehydrogenase isoenzyme 1 in serum

A new method for measuring lactate dehydrogenase (EC 1.1.1.27) isoenzyme 1 using sodium perchlorate as a chaotropic chemical selective inhibitor of all lactate dehydrogenase isoenzymes containing M-subunit was evaluated. Results with this method were precise (between-day coefficient of variation less than 9%), highly linear (coefficient of correlation = 0.9998) and correlated well with lactate dehydrogenase isoenzyme 1 as determined by the conventional immunological method (coefficient of correlation = 0.976). The reference interval for 307 healthy subjects was estimated to be 23-46 U/l (95% central range, determined non-parametrically). Being simple, convenient and amenable to automation, the method provides a substantial saving in labour and reagent costs when compared with alternative analytical approaches.     

Evaluation of a new strategy for detection of thyroid dysfunction in the routine laboratory

We assessed the use of a new strategy for detecting thyroid disorders, utilizing a sensitive assay for concentrations of thyrotropin (TSH) and free thyroid hormone in serum as follow-up tests. Of 1279 patients who were not on thyroxin (T4) replacement treatment, 82% could be classified as euthyroid and would require no further tests. In patients who were on T4 replacement, 41% fell into the euthyroid category and would require no further tests. Using this strategy to replace our existing strategy of free thyroxin as a "first-line" test would reduce the proportion of patients who would require one or more follow-up tests from 49% to 24%.     

A rapid allele variant discrimination method for Yersinia pestis strains based on high-resolution melting curve analysis

Yersinia pestis isolates were genotyped analyzing the polymorphic DNA regions named variable number tandem repeats (VNTR). Allele variants were studied by high-resolution melting analysis (HRMA) of polymerase chain reaction fragments obtained for 25 VNTR loci. After comparison with previous results, 14 loci gave distinguishable normalized melting curves and allowed to correctly assign alleles. This HRMA typing technique permits to differentiate Y. pestis isolates and turned out to be robust, reproducible, and cheap.     

Evaluation of a new, rapid latex test for the detection of heterophil antibody.

OBJECTIVE. To compare the performance of the MONO-LEX system to that of the MONO-TEST in detecting infectious mononucleosis (IM) heterophil antibodies. SETTING. Baptist Regional Laboratories, Memphis, Tennessee. PRACTICE DESCRIPTION. Not applicable. PRODUCT COMPARISON. The MONO-LEX system, manufactured by Trinity Laboratories, Raleigh, North Carolina, distributed by Gull Laboratories, Salt Lake City, Utah, and the MONO-TEST kit, manufactured by Wampole Laboratories, Cranbury, New Jersey, are agglutination assays that show visible agglutination when reagents are mixed with serum or plasma containing IM heterophil antibodies. MAIN OUTCOME MEASUREMENTS. Accuracy in detecting heterophil antibodies in the study specimens, ease of interpreting test results, and cost-effectiveness. RESULTS. Of the 139 specimens tested, 132 produced the same results using both products and seven produced discrepant results. The possibility that the MONO-TEST produced a "prozone effect" was eliminated. Titration of sera that tested positive for heterophil antibody by both methods revealed titers as high as 1:152 by the MONO-LEX compared with 1:128 by the MONO-TEST. A total of 31 specimens that tested positive for IgM antibodies to Epstein-Barr virus nuclear antigen by enzyme immunoassay were assayed using the two methods; MONO-LEX detected heterophil antibodies in eight sera while the MONO-TEST detected antibody in only four samples. CONCLUSION. The MONO-LEX surpassed the MONO-TEST in sensitivity, cost-effectiveness, and ease of interpretation.