A murine monoclonal anti-N, BIRMA-N, suitable for blood grouping in an automated system

Summary. BIRMA-N, a murine monoclonal anti-N antibody of the IgGl subclass, was assessed for suitability as a blood grouping reagent on the Olympus PK7100 automated blood grouping machine. At a selected dilution and over the pH range 5·0·8·0, the antibody performed accurately in this system as confirmed by parallel manual testing of donor blood samples with human anti-N and commercial monoclonal anti-N reagents. These findings show BIRMA-N to be extremely suitable for N typing blood samples in an automated system providing a convenient, objective and cost-effective method for large scale typing of the blood donor population.     

A novel microplate agglutination method for blood grouping and reverse typing without the need for centrifugation

BACKGROUND: Current agglutination tests and solid-phase adherence methods, employed as the techniques for RBC typing and antibody screening, require centrifugation and washing steps. This report describes a novel agglutination method for forward and reverse grouping that is based on the formation of an RBC monolayer on a microplate without the need for centrifugation and washing. STUDY DESIGN AND METHODS: In a comparative study, 2225 samples from healthy regular blood donors were tested for ABO, Rh (D, C, c, E, and e), K, and reverse grouping, in parallel, by the new microplate agglutination method and a commercially available blood testing system, which served as a reference method. RESULTS: In the case of forward grouping, 0.37 percent of samples tested were false negative in the new method and 1.35 percent tested false negative in the reference blood testing system. In addition, the reverse grouping reference method showed 0.4 percent false-positive and 2.6 percent false-negative results. In contrast, the new method gave false-positive results in only 0.09 percent and false-negative results in 0.67 percent of the cases tested. CONCLUSION: These results, as well as the possibility of adapting this method to a fully automated system, suggest that our novel agglutination method could be an important contribution to the field of immunohematology.     

Post-transfusion hepatitis after open-heart surgery in Finland—a prospective study

Summary. A countrywide prospective study on open-heart surgery patients was performed between 1987 and 1989 to determine the prevalence and nature of post-transfusion hepatitis in Finland. Altogether 685 coronary by-pass operation patients, who received on average 12·3 units of blood products, were postoperatively followed for 6 months. Ten blood samples were drawn from each patient. Hepatitis was diagnosed when the alanine aminotransferase values exceeded the upper normal value 2·5 times in one sample and twice in another, and non-viral causes could reasonably be excluded. Eleven hepatitis cases (1·6%) were recorded with a mean incubation period of 8·4 weeks; all represented the non-A, non-B type. The majority had mild symptoms or were asymptomatic but two became icteric. Six patients (55%) had abnormal alanine aminotransferase values for at least 6 months, which indicates possible chronicity. These 685 open-heart surgery patients received a total of 8,436 units of blood products; thus the rate of NANBH cases per 1000 units was as low as 1·3. This is less than recently reported in six other prospective studies.     

Evaluation of immunohematologic routine methods using the new erythrocyte-magnetized technology on the QWALYS 2 system

BACKGROUND: QWALYS 2 is a fully automated system for ABO/D grouping, Rh phenotyping, K typing, and antibody screening (ABS). Its new erythrocyte-magnetized technology (EMT) is based on the use of magnetic nanoparticles and avoids centrifugation and washing steps.
STUDY DESIGN AND METHODS: Overall 499 blood samples were tested with our routine blood bank methods for ABO/D grouping, 313 samples for Rh phenotyping and K typing (microtiter plates; Olympus PK 7200), and 478 samples for ABS (gel centrifugation technique, DiaMed). All samples were tested in parallel with the EMT.
RESULTS: In 496 of 499 samples (99.4%), a complete concordance between the observed (QWALYS 2) and the expected results for ABO/D grouping was found. One sample with a weak A in an AB blood group and 2 samples with a weak D were not detected by the QWALYS system. Rh phenotyping and K tests revealed a 100% concordance. In the two ABS techniques, 427 samples were negative in both and 15 samples showed the same antibody specificity in both. Three immunoglobulin M antibodies were as expected negative in EMT and positive by DiaMed. In 32 cases (6.7%), false-positive reactions were observed by EMT due to 22 unspecific reactions (4.6%) and 10 lipemic or fibrinic plasmas (2.1%). One autoantibody was found by EMT only.
CONCLUSION: The EMT is reliably suited to ABO/D grouping, Rh phenotyping, and K testing and is suitable to detect immunoglobulin G red blood cell alloantibodies as well. The rate of false-positive reactions in ABS due to lipemic and fibrinic samples needs to be reduced.     

Feasibility of implementing an automated culture system for bacteria screening in platelets in the blood bank routine

summary .  Bacterial contamination of blood components is the principal infectious complication linked to transfusion. The aim of the study was to evaluate the applicability of an automated culture system for platelets. 10 141 platelet concentrates were cultured individually and in pools of five on storage days 1 and 7 using Bact/Alert system aerobic bottles. A modified collection bag was used for improved sampling. Five-millilitre samples were cultured at 37 °C for 7 days. Only those samples where the same bacteria were identified in reculture were considered true positives (TP). Homogeneity of proportions was tested by Fisher's exact test. The rate of TP was 30 per 100 000 (95% CI, 6·1–86·4) sampling on day 1; 33 per 100 000 (95% CI, 7–96) on day 7; and 40 per 100 000 (95% CI, 1·28–122·4) if the screening was based on taking both samples (day 1 and 7). Only one TP was detected in the pool testing. The time for detection among TPs on day 1 ranged between 30 and 134 h. The system is not considered practical for use as a routine screening method, as the time for detection is too long. Pool testing is insensitive. Faster screening methods or pathogen-inactivation systems are needed.     

Blood surveillance and detection on platelet bacterial contamination associated with septic events

The objective of this study was to evaluate the risk of transfusion-associated septic events in Taiwan. In Taiwan, most blood components are provided from blood centres; so platelet (PLT) bacterial contaminations are rarely reported. The study's aim is to investigate the prevalence of PLT bacterial contamination in Kaoshiung Armed Forces General Hospital by using BacT/ALERT system for routine screening.
A total of 82 apheresis and 2256 whole blood-derived PLT units were tested. A measured quantity of 1 mL aliquots were taken as samplings from all blood bag tubing of PLT units, and then further incubated in a bacterial detection system (BacT/ALERT). The subcultures of true-positive bottles underwent bacterial identification by using Vitek system, microscopic observation and culture-based methods. Eight units (0·34%, 8 of 2338) were found to have bacterial contamination. The true-positive rate of the whole blood-derived and apheresis PLTs was 0·31% (7 of 2256) and 1·22% (1 of 82), respectively. Six microorganisms were identified with the most dominate being Staphylococcus epidermidis . One case of transfusion-associated sepsis was confirmed; in addition, the holding period of PLTs ( F = 4·522, P = 0·034) and positive detection of PLT bacterial contamination ( F = 46·605 ,P < 0·001) were associated with post-transfusion sepsis. Thus, in this study, although the transfusion-associated septic event was rarely found and PLT units were provided from blood centres, bacterial screening was necessary to safely quarantine the transfusion. The holding period of PLT units should be no more than 4 days in order to avoid possible bacterial contamination.     

Understanding non-disclosure of deferrable risk: a study of blood donors with a history of intravenous drug use

summary . Non-disclosure of deferrable risk has received little attention in the literature. We examined deferrable risk (history of intravenous drug use [IVDU]) and donor attitudes towards truthfulness, the screening process and interpretation of the screening question as well as risk profile. Donors negative for all markers with a self-reported history of IVDU ( N = 30) and matched controls were identified from an anonymous mail-out survey. In a separate survey, hepatitis C virus (HCV)-positive donors participated in a telephone interview, from which all those with IVDU history ( N = 29) were selected plus matched controls (combined total 59 IVDU, 236 controls). IVDU donors, when compared with matched controls, tended to believe that it is OK not to answer truthfully if one believes that her/his blood is safe (18·6% vs. 4·7%) and that some questions are a little too personal (35·6% vs. 21·7%). IVDU donors were more likely than controls to say they failed to acknowledge screening questions appropriately (23% vs. 2·2%) or to agree that IVDU questions are mainly about recent drug taking or sharing needles (29% vs. 11%) even though the screening question asked about IVDU ever without any such qualifiers. IVDU donors were also more likely to have other lifestyle/risk factors such as history of sex with IVDU (45·5% vs. 1·7%). Donors with deferrable IVDU history may rationalise that revealing their status is not necessary and may misinterpret the question. Failure to acknowledge risk behaviour is complex, and some degree of non-disclosure may be an inherent part of pre-donation screening.     

Anti-HBc screening in Egyptian blood donors reduces the risk of hepatitis B virus transmission

summary .  Occult hepatitis B virus (HBV) in blood donors is considered as a potential risk for transmission of HBV infection. The aim of this study was to determine the prevalence of anti-hepatitis B core antibody (anti-HBC) positivity in Egyptian blood donations as well as to estimate the frequency of HBV-DNA in anti-HBc-positive donations. The study included 760 Egyptian healthy blood donors, representing 26 different Egyptian governorates screened according to routine practice for the presence of hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibodies (Abs), HIV-1/2 Abs and Treponema Abs. The accepted blood units for donation were tested for the presence of total anti-HBc Abs by two tests. Positive units for anti-HBc were further tested for HBV-DNA by polymerase chain reaction. According to routine screening, a total of 48/760 units (6·3%) were rejected [38 (5%) HCV-Ab-positive units, 9 (1·18%) HbsAg-positive units and 1 (0·13%) Treponema-Ab-positive unit]. Among the accepted blood units for donation, prevalence of anti-HBc was 78/712 units (10·96%). HBV-DNA was detected in 9/78 (11·54%) of the anti-HBc-positive units, and thus, occult HBV infection was detected in 9/712 (1·26%) of the accepted blood donations. Implementing anti-HBc test to the routine assay for the forthcoming two decades would certainly eliminate possible HBV-infected units. Rejection of these units will be beneficial to decrease the risk of HBV transmission with its potential consequences particularly in immunocompromised recipients.     

戴安娜全自动血型仪在血型鉴定及交叉配血中的应用

目的：探讨戴安娜全自动血型仪在血型鉴定及交叉配血中的应用。方法使用全自动血型仪和传统试管法检测2300份标本的血型;用微柱凝胶法和聚凝胺法对900例患者进行交叉配血试验。结果全自动血型仪和试管法检测血型一次性判读准确率分别为99．87％、100．00％;在900例交叉配血试验中,微柱凝胶法配血不合30例,主侧不合3例,次侧不合27例,将微柱凝胶法配血不合的标本用聚凝胺法检测,主侧不合3例,次侧不合3例。结论全自动血型仪用于 ABO 血型和 RhD 血型检测安全、快速、可靠、灵敏度高;微柱凝胶法进行交叉配血较敏感,但假凝集及不规则抗体的存在会导致配血困难,耗时较长;聚凝胺法简便、快速、假阳性较少,但有可能导致抗体漏检。     

Handheld diffuse reflectance spectroscopy system for noninvasive quantification of neonatal bilirubin and hemoglobin concentrations: a pilot study

The prevalence rate of neonatal jaundice can reach 80%, of which 5% may develop dangerous hemolytic jaundice. The blood test for obtaining bilirubin and hemoglobin concentration is the gold standard for diagnosing hemolytic jaundice; however, frequently drawing blood from jaundice neonates for the screening purpose is not practical. We have developed a handheld diffuse reflectance spectroscopy system to noninvasively determine the bilirubin and hemoglobin levels in neonates. Our study showed that the correlation coefficients were 0.95 and 0.80 for bilirubin and hemoglobin between the results from the blood tests and our handheld system, respectively. This handheld system could be an effective tool for screening hemolytic jaundice.     

The serum sodium to urinary sodium to (serum potassium)2 to urinary potassium (SUSPPUP) ratio in patients with primary aldosteronism

Background  The aldosterone-to-renin ratio (ARR) is an established diagnostic tool in the screening for primary aldosteronism (PA). However, hormonal determinations are time consuming and expensive. Therefore, we studied the effectiveness of the serum sodium to urinary sodium to (serum potassium)² to urinary potassium (SUSPPUP) ratio in the diagnosis of PA.
Design  This study included 35 patients with PA, 71 patients with essential hypertension to whom this diagnosis could be excluded, 23 normal subjects without hypertension, and 22 patients with primary adrenal insufficiency. We compared the SUSPPUP ratios with the ARR in these patient groups.
Results  We show that the ARR distinguished PA from essential hypertension with a sensitivity of 94·2% and a specificity of 92·1% at a cutoff of 33 (ng L⁻¹: ng L⁻¹). It correlated well with the SUSPPUP ratio. The sensitivity and specificity of SUSPPUP was 88·6% and 85·9% at a cutoff of 5.3 (mmol L⁻¹)⁻¹, respectively, and thus not as good as the ARR.
Conclusions  The ARR is a good parameter in the screening for PA. The SUSPPUP ratio is a cheap and rapid tool to assess the extent of mineralocorticoid excess and, therefore, can be offered to more patients. In addition, the application of the SUSPPUP ratio can be extended to patients who suffer from other forms of mineralocorticoid hypertension (e.g. with low aldosterone levels).     

单人份核酸检测在血液筛查中的应用

目的 初步了解单人份核酸检测方法在无偿献血者血液筛查中应用的利弊.方法 利用Procleix TIGRIS全自动核酸检测系统,结合血站常规的血清学检测,平行检测无偿献血者血液标本,对核酸检测初检反应性、复检非反应性的标本应用其它检测方法进行验证;对核酸检测初检反应性且鉴别阳性的部分标本,应用阴性血浆做倍比稀释,模拟混合NAT检测.结果 在总共12 005份标本中,核酸检测ULTRIO初检反应性标本共51例,经复检非反应性或鉴别试验阴性的标本共17例(33.3％),其中有6例经罗氏核酸检测为HBV阳性,即不可重复的标本存在真阳性的可能.模拟混样检测结果显示,经混样检测后阳性检出率明显降低,尤其是病毒拷贝数比较低的标本.结论 单人份核酸检测在血液筛查的应用中有利有弊,应根据需要选择.     

Performance of three automated fourth-generation combined HIV antigen/antibody assays in large-scale screening of blood donors and clinical samples

summary .  Since the introduction in the mid-1980s, HIV testing has gradually improved both in terms of sensitivity and specificity. The so-called fourth generation of tests, combined HIV antigen/antibody assays, has now been introduced. This study compares three automated combined assays with older third-generation antibody assays in large-scale screening. Serum samples from routine screening of blood and plasma donors and clinical samples were investigated for specificity evaluation. Three fourth-generation combination assays from one manufacturer were compared with three older third-generation antibody assays from the same manufacturer. More than 40 000 samples per assay were included. For sensitivity, selected panels of confirmed HIV-1- and HIV-2-positive samples as well as seroconversion samples (HIV-1) from commercial panels and also from patients who appeared during the evaluation were used. The specificities of the fourth-generation tests were 99·91% (AxSYM), 99·95% (ARCHITECT) and 99·97% (PRISM) after repeated testing. Some specificity variation between reagent batches was observed. All HIV-1-positive samples were reactive by the three fourth-generation systems. HIV-1 seroconversion samples and panels were reactive earlier than by antibody-only tests. As for HIV-2 samples, AxSYM failed to detect one ( n  = 40), whereas PRISM and ARCHITECT detected all ( n  = 16 for PRISM and n  = 52 for ARCHITECT). The new HIV antigen/antibody combination assay systems were found to have high sensitivity and specificity. The instruments provided a rational and easy way of testing at large scale.     

汉族健康人群血管紧张素转换酶多态性及其血清水平的研究

目的调查汉族健康人群血管紧张素转换酶(ACE)基因的单核苷酸多态性(SNP)分布与血清ACE水平的相关性。方法提取132例健康个体外周血有核细胞DNA,应用荧光标记单碱基延伸分型技术及寡核苷酸微阵列芯片杂交技术检测ACE基因的2个标签SNP(tag SNP)rs4353和rs4305;应用单一试剂速率法检测血清ACE水平。结果汉族健康人群ACE基因rs4353多态性中AA型占23.4%,AG型占47.7%,GG型占28.9%;rs4305多态性中AA型占10.1%,AG型占49.6%,GG型占40.3%。rs4353的AA和AG基因型血清ACE水平明显高于GG基因型;rs4305的AG基因型血清ACE水平明显高于GG基因型(P0.05)。结论 ACE基因2个tag SNP的基因型与血清ACE水平密切相关。     

A novel method for quantitation of acylglycines in human dried blood spots by UPLC-tandem mass spectrometry

BackgroundSeveral acylcarnitines used as primary markers on dried blood filter papers (DBS) for newborn screening lack specificity and contribute to a higher false positive rate. The analysis of urine acylglycines is useful in the diagnosis of inborn errors of metabolism (IEM) including medium chain acyl-CoA dehydrogenase deficiency (MCADD), isovaleric acidemia, and beta-ketothiolase deficiency (BKTD). Currently, no method for analyzing acylglycines from DBS has been published.MethodsAcylglycines were extracted from two 3.2 mm DBS punches and butylated using Butanol-HCl. Ultra Performance Liquid Chromatography (UPLC-MS/MS) with run time of 10 min permits resolution and quantitation of 15 acylglycines; including several isobaric. Method development was completed. Reference intervals (n = 573) were established for four birth weight groups. Furthermore, samples from patients with a confirmed IEM (n = 11), and false positive screens (n = 78) were analyzed to validate the interpretation obtained from the newly established reference intervals.ResultsCalibration curves were linear from 0.005 to 25.0 μM. Ion suppression was evaluated as minimal (2 to 10%). Samples from known patients were used to validate the reference intervals. For C5OH-related disorders, tiglylglycine (TG), TG/acetylglycine (AG) ratio, 3methylcrotonylglycine (3MCG) and 3MCG/AG ratio increased specificity. Propionylglycine (PG) and PG/acetylglycine ratio were two discriminatory markers in the investigation of C3-related disorders. Hexanoylglycine (HG), octanoylglycine (OG), suberylglycine (SG), and the ratios HG/AG, OC/AG and SG/AG were excellent markers of MCADD deficiency.ConclusionThis method shows potential application as a second tier screen in order to reduce the false positive rate for a number of IEM targeted by newborn screening.     

Transfusion trigger – how precise are we? Intraoperative blood transfusion practices in a tertiary centre in Nigeria

summary .  To determine how well anaesthetists in Nigeria determine the need for transfusion based solely on physiological variables and estimated blood loss. To determine the incidence of inappropriate blood transfusion. Anaesthetists in our hospital determine when to transfuse patients based solely on clinical acumen. This may result in inappropriate transfusion especially in this subregion where blood donors are scarce and risk of transmission of infection high. All surgical patients requiring blood transfusion were prospectively studied over 3 months. Transfusion was based solely on the discretion of the attending anaesthetist. Haemoglobin (Hb) concentration was measured prior to transfusion and 24 h postoperatively. Appropriate transfusion was defined as blood transfusion at Hb < 8 g dL⁻¹ or 10 g dL⁻¹ in the elderly and those with medical comorbidities. The trigger for transfusion was documented as well as estimated blood loss. Thirty-four patients were studied. The mean pretransfusion Hb was 8·09 ± 2·45 g dL⁻¹ (range 4·6–14·2). Twenty-one patients (61·8%) had appropriate blood transfusion. The commonest transfusion triggers were clinical pallor (82·4%), excessive blood loss (76·4%), delayed capillary refill (55·9%) and severe hypotension (50%). The use of near patient monitoring devices might further improve blood transfusion practice in this setting where donor blood is scarce.     

Causes of failure of a barcode-based pretransfusion check at the bedside: experience in a university hospital

summary .  The objective of this study was to assess the cause of failure of bedside barcode identification before blood administration. The bedside check is the most critical step for prevention of mistransfusion. A barcode patient-blood unit identification system was implemented in all inpatient wards, operating rooms and an outpatient haematology unit in July 2002. The transfusion service monitored compliance with bedside barcode identification and checked it at 24 h or 1 h after issuing of blood. If electronic checking was not completed at that time, the transfusion service clarified the cause of failure and indicated the immediate use of the issued blood when it was not yet transfused. From April 2004 to December 2007, a total of 43 068 blood components were transfused without a single mistransfusion and 958 transfusions (2·2%) were performed without electronic checking. The overall compliance rate with bedside barcode identification was 97·8%, and it was 99·5% in the past 6 months. The cause of failure of bedside barcode identification was human error in 811 cases (84·7%), handheld device error in 74 (7·7%), system error in 50 (5·2%) and wristband error in 23 (2·4%). The number of errors leading to failure of bedside barcode identification was decreased for human errors, especially manipulation errors, after initiation of notification at 1 h after issuing of blood. The transfusion service may have an important role in increasing transfusion safety by monitoring compliance with bedside verification and bedside use of issued blood.     

阴离子间隙在诊断混合型酸碱平衡紊乱中的作用

目的：应用阴离子间隙（AG）值判断混合型酸碱平衡紊乱。方法：抽取动脉血2ml均以肝素抗凝即时送检。以公式AG=[Na＋]-[HCO3]-[CL-]计算AG值,参考范围8～16mmol／I。。酸碱血气分析结果按预计代偿公式计算,并结合AG值及临床诊断、病史、用药等情况,做出酸碱平衡紊乱类型的诊断。在此基础上以AG〉16mmol／L为筛选标准,筛选出63例;63例又分为2组：单纯型酸碱平衡紊乱7例和混合型酸碱平衡紊乱56例。全部数据以x±s表示,组间比较采用方差分析。结果：混合型酸碱平衡紊乱AG值升高的例数明显多于单纯型酸碱平衡紊乱AG值升高的例数（P〈0．05）。结论：因此,AG值升高,可帮助诊断混合型酸碱平衡紊乱,特别是对伴有代谢性酸中毒的混合型酸碱平衡紊乱的诊断具有重要意义。     

Detection improvement of cytomegalovirus antigen in human peripheral blood using monoclonal antibodies and automated reading of cell preparations

Abstract. One of the major drawbacks in cytomegalovirus (CMV)-antigenaemia detection for diagnosis of active CMV infection is the low number of CMV-antigen positive cells present in peripheral blood. It is therefore necessary to screen large numbers of peripheral blood granulocytes to find only a few antigen-positive cells. We have optimized this detection by testing several monoclonal antibodies (mAb) to CMV-antigens (mAbs C10/C11, C12, BM222, E13 and SL20). In total 550 blood samples from 40 patients were investigated. More blood samples were found positive with mAb C12 than with the other mAbs. Also the average number of positive cells per slide was highest for mAb C12. Furthermore, duplicate slides were examined automatically using an image analysis system (LEYTAS) and compared to visual detection (cytospin slides). The detection sensitivity of both screening methods was compared for mAb C12. In total 360 slides were analysed, from positive as well as negative blood samples. The sensitivity of the automated screening was 93% and for the visual evaluation of the cytospin slides 73%. In conclusion, mAb C12 was the most suitable of the mAbs tested for detection of antigenaemia, and automatic detection of CMV antigenaemia with image analysis of slides is a sensitive method due to the large numbers of cells that can be screened.