献血者抗-HCV ELISA检测有反应性与确证实验的比较

目的:了解国产ELISA间接法试剂和双抗原夹心法的检测效能,探讨确证结果用于试剂选择,灰区范围设置的理论和依据。方法:采用重组免疫印迹试验(RIBA)对ELISA方法检测有反应性及灰区的44份标本进行检测。结果:3个厂家的抗-HCV有反应性标本经RIBA实验确证后,假阳性率分别为70.6%、44.1%、2.9%,灰区标本15例,未确认阳性检出。结论:为确保血液质量,血筛实验室应选择灵敏度和特异性双优的试剂,以有效提高抗-HCV有反应性标本的检出率。在献血者管理中,参考确证结果用于献血者反馈,特别是长期固定献血者,对单试剂反应者经6个月以上的屏蔽期可以重新参加检测确认,合适献血的可进入归队献血程序。     

抗-HCVELISA间接法与双抗原夹心法试剂的应用对比评价

目的:对比研究国产抗-HCV ELISA间接法和双抗原夹心法试剂的检测效能,探讨血站抗-HCV检测模式。方法:选择1种双抗原夹心法酶联免疫试剂、2种间接法酶联免疫试剂分别检测34 593名无偿献血者血样,采用重组免疫印迹试验(RIBA)对其中有反应性的44份标本进行确认,并用BBI血清盘对这2种检测试剂进行考核评价。结果:科华、新创和万泰3个厂家的抗-HCV有反应性及灰区标本经RIBA实验确证后,假阳性率分别为31%、63%、13%。万泰双抗原夹心法与间接法相比,增加了反应强度、降低了假阳性率且缩短了窗口期。结论:为确保血液质量,血筛实验室应选择灵敏度和特异性双优的试剂,采用间接和双抗原夹心2种不同的ELISA试剂检测HCV抗体优于2种间接ELISA试剂,不仅提高抗-HCV有反应性标本的检出率,而且减少血液因假阳性造成的浪费。     

间接法和夹心法HCV抗体诊断试剂盒的诊断性能评价与选择

目的对国产双抗原夹心酶联免疫法和间接酶联免疫法丙型肝炎抗原检测试剂进行诊断性能评价与选择。方法选择1种夹心法和3种间接法国产检测试剂,同时对60份血清盘标本和40份血液筛查标本进行检测,血液筛查标本的检测结果为阳性或灰区,并经确认试验确认。试剂间比较采用配对卡方检验;对假阴性率进行R×C列联表检验。结果 3种间接法试剂和夹心法试剂的灵敏度分别为90.2%、78.0%、95.1%和97.6%;特异度分别为78.1%、72.6%、94.1%和100%。夹心法的分析灵敏度比间接法高4~8倍,不同试剂及试剂组合的R×C列联表检验结果:χ2=29.898,P0.05。结论夹心法试剂诊断特性优于间接法试剂,夹心法与间接法试剂搭配,可明显降低假阴性率,有效防止漏检。     

武汉献血人群抗-HCV ELISA检测反应性标本联合Realtime-PCR的研究

目的:对现有的2种国产抗-HCV ELISA试剂检出的反应性标本进行Realtime-PCR扩增,对结果进行分析,比较2种方法的检出率。为制定ELISA检测结果假阳性的献血者献血资格的恢复措施提供依据。方法:对日常工作中的检测标本用2种抗-HCV ELISA两步法试剂做初检,反应性结果再次双孔复试。对任何一种试剂经复试检测后仍为反应性的标本进行Realtime-PCR扩增,对所有检测结果进行分析。结果:共检测无偿献血标本63 169份,其中检出抗-HCV反应性标本206份,对206份标本进行Realtime-PCR扩增,共扩增出91例HCV-RNA阳性标本,53例科华试剂单反应性标本中仅2例HCV-RNA结果为阳性,41例新创试剂单反应性标本中6例HCV-RNA结果为阳性。ELISA试剂检出的标本S/CO值在不同的区间内的,都有HCV-RNA为阳性的标本。结论:ELISA试剂检测出的抗-HCV标本很多可能为假阳性,特别是单侧试剂呈反应性的标本。但即使ELISA检测S/CO值仅在灰区的单试剂反应性标本,仍不能排除为HCV感染者。     

试剂盒平衡时间对抗-HCV检测结果的影响因素分析

目的：探讨ELISA试剂盒平衡时间对抗-HCV检测结果的影响;研究抗-HCV灰区献血者再次献血的可行性和必要性。方法：变化试剂盒平衡时间,测定不同平衡时间的S/Co值。对部分灰区标本进行重组免疫印迹试验（RIBA）;应用荧光定量-聚合酶链反应（FQ-PCR）检测灰区标本HCVRNA;应用速率法检测灰区和抗-HCV阴性血清ALT。结果：ELISA试剂盒平衡时间在30min内,1NCU/ml抗-HCV质控、抗-HCV灰区标本的S/CO值随着平衡时间的延长而增加（P〈0.05）,但30min后变化不明显（P〉0.05）。32份灰区标本经Murex试剂筛选后的5份标本进行了RIBA检测,结果为2份可疑,3份阴性。FQ-PCR定量检测均为阴性;速率法ALT检测抗-HCV灰区和抗-HCV阴性标本结果分别为（19.20±7.38）U/L、（16.58±7.08）U/L。2者结果均〈40U/L,差异有统计学意义（t=1.48,P〉0.05）。结论：抗-HCV试剂盒在检测前应先在室温下平衡30min以上,否则会降低标本的S/Co值,影响结果判断;抗-HCV灰区标本ALT检测结果正常;抗-HCV灰区的献血者在核酸检测结果为阴性的前提下可考虑再次献血。     

HBsAg和抗-HCV酶联免疫检测与血液病毒核酸筛查技术之间的相关性分析

目的探讨HBsAg和抗-HCV酶联免疫检测方法与血液病毒核酸筛查技术之间的相关性。方法对我院血液科2011年12月到2013年12月血样标本12 300个,首先进行HBsAg和抗-HCV ELISA检测,再利用中和试验和重组免疫印迹试验(RIBA)进行确认检测,并对确认检测阳性和阴性样本行血液病毒核酸筛查,分析ELISA检测与血液病毒核酸筛查之间的相关性。结果经过HBsAg ELISA国产试剂和进口试剂检测血样标本12 300个,221个为阳性,占1.80%,国产和进口试剂检测一致率为99.72%,经过配对卡方检验,两种试剂间差异无统计学意义(P0.05);抗-HCV ELISA检测阳性112个,占0.91%,国产和进口试剂检测一致率为99.60%,两种试剂间差异无统计学意义(P0.05);HBsAg经过再次确认检测其中阳性201个,阴性20个,再次确认检测与国产和进口试剂检测一致率为90.95%;抗-HCV再次确认检测其中阳性55个、阴性43个、可疑14个,再次确认检测与国产和进口试剂检测一致率为61.61%;经过核酸检测技术(NAT)检测HBV DNA阳性和阴性分别为203个、18个,HCV RNA阳性和阴性分别为70个、42个。将两种因素合并计算,ELISA检测联合再次确认检测灵敏度为97.44%、特异度93.33%。结论 HBsAg和抗-HCV ELISA检测具有较高的灵敏度和特异度,但是由于使用ELISA试剂盒不同,常存在误检,而血液病毒核酸筛查技术可以减少这种误检,再次提高检出率。     

抗-HCV ELISA试剂评价体系的建立及检测结果

目的:建立丙型肝炎病毒抗体(抗-HCV)酶联免疫吸附试验(ELISA)诊断试剂评价参考系统,筛选出适合本地区的献血员抗-HCV检测策略。方法:使用Chiron的RIBA HCV 3.0试剂确认献血员中筛查出抗-HCV阳性和阴性的血清标本,建立抗-HCV参比血清,评价8种国内外抗-HCV EIA试剂的灵敏度、特异度、符合率等指标。结果:构建了抗-HCV诊断试剂评价质控体系,分别包括24份抗-HCV阳性标本、24份抗-HCV阴性标本及8份用于灵敏度评价的系列稀释标本;8种抗-HCV EIA试剂对参比血清的检测结果 Kappa值分别为0.67、0.71、0.75、0.75、0.88、0.79、0.58。结论:自制抗-HCV试剂评价体系更适合各地的试剂评价工作,在制定筛查策略时,双抗原夹心法试剂优于间接法试剂。     

丙型肝炎病毒在献血者中的交叉感染

目的观察血站在采血（浆）过程中致丙型肝炎病毒在献血者中的交叉感染．方法采用酶联免疫吸附试验（ELISA法），对2601名职业献血者进行抗-HCV检测．其中对检测抗-HCV阳性者，重复用两种不同生产厂家的丙肝抗体检测试剂再次化验，加以确认结果发现曾接受手工分离法单采血浆史的献血者2388人（单采血浆组），有159人再次化验证实抗-HCV阳性，阳性率占单系血浆组献血者的6．66％，其中单采血浆超过5次的献血者123人，5次以下36人，而从未单采血浆的213名献血者（非单采血浆组）中，仅有6人抗-HCV阳性，占2．18％．两组结果有显著差异；另外通过对正常人群（样本为淄博市公民无偿献血者）抗-HCV测定调查发现，有单采血浆史的献血者抗-HCV阳性率远高于正常人群中抗-HCV阳性率为2．03％的比例，而没有单采血浆史的献血者抗-HCV阳性率接近正常的群调查结果．结论手工分离法单采血浆过程中存在着HCV病毒交叉感染问题．     

113例献血者梅毒抗体ELISA法阳性与TPPA确证结果比对分析

目的:了解梅毒ELISA法检测阳性献血者采用明胶颗粒凝集试验(TPPA)确证结果情况。方法:每一样本均先经2种不同厂家ELISA法试剂进行检测,对单试剂或双试剂阳性的标本采用TPPA进行确证试验。结果:ELISA法检测阳性结果与TPPA确证结果符合率为80.53%,其中ELISA法双试剂阳性结果 TPPA确证阳性率为77.88%,ELISA法单试剂阳性TPPA确证阳性率分别为0和2.65%,2种ELISA法试剂检测为强阳性(s/co≥5)结果的标本确证阳性率分别为98.67%和100%,反应强度(s/co值)越大,确证阳性率越高。结论:采供血机构对于梅毒ELISA法双试剂阳性献血者可采取永久屏蔽策略,对于ELISA法单试剂阳性献血者,应进行TPPA确证试验后根据确证试验结果再进行献血者回访和处理。对梅毒ELISA法单试剂阳性、TPPA确证阳性结果的献血者可进行屏蔽处理;对于TPPA确证阴性献血者可纳入献血者保留、归队人群进行管理。     

绍兴地区无偿献血者血液核酸检测效果评估

目的:评估在原有血液检测技术的基础上增加核酸检测技术的效果。方法:献血者标本使用生化仪检测ALT,使用2种ELISA试剂检测HBsAg、抗-HCV抗体、抗-HIV抗体、抗-TP抗体,检测结果阴性及单试剂检测有反应性的标本进行核酸检测,核酸检测使用罗氏Cobas s201核酸检测系统。结果:核酸检测前37 296人份标本的传染病标志物阳性率为1.04%,核酸检测23 834人份,检出阳性标本35例,其中34例为HBV DNA阳性,1例为HIV RNA阳性,阳性率0.15%。结论:ELISA检测阴性血液存在较高的HBV感染风险,增加核酸检测技术可以进一步增强血液安全。     

Capillary blood sampling for self-monitoring of blood glucose

New and emerging capillary blood sampling technologies for self-monitoring of blood glucose (SMBG) are reviewed for their impact on factors pertaining to users such as pain, and from the standpoint of skin physiology and technical feasibility. Innovative blood sampling techniques based on lancets for skin penetration on nonfinger (alternate) sites such as the forearm seem to be virtually painless, convenient and cost effective as compared to other methods such as laser-based perforation of fingertips. Alternate site blood sampling with new lancet devices appears not only medically sound but also technically practical and user-friendly. It is anticipated that alternate site blood sampling techniques would improve compliance rate and, consequently, outcome of treatment for patients with diabetes.     

A study-screening of blood donors for blood transmissible diseases

Aims

Blood donors are of voluntary and replacement type. All donors, especially voluntary, are considered as slow risk for seropositive status for Hepatitis B and C, HIV and syphilis. The present study endeavors to screen blood donors-a slow risk group and evaluate the resultant data.

Methodology

We screened 23,068 donors serologically over 2 years for the above blood transmissible diseases. Serum alanine aminotranferase (ALT) and bilirubin were evaluated as surrogate markers in hepatitis B and C positive donors.

Results

Seroprevalence rates were found to be HIV (1.96 %), syphilis (2.15 %), hepatitis B (1.98 %) and hepatitis C (0.9 %). Majority donors were voluntary (70.37 %) and male (96.2 %). However seroprevalence rates showed no significant difference: voluntary (7.02 %), replacement (6.67 %) male (6.85 %) and female (6.95 %). HCV and HIV showed highest (29.6 %) while HBV and HCV (2.5 %) showed lowest concomitance. Serum ALT and bilirubin were not effective surrogate markers. No demographic or behavioral variable was found as a significant risk factor.

Conclusion

Thus, all donors need adequate privacy, information, counseling and motivation in order to reduce the seropositive rates in donors. Advent of sensitive tests renders surrogate markers redundant.     

Significance of mean blood pressure for blood pressure control

The significance of pulse pressure (PP) and mean blood pressure (MBP) for blood pressure (BP) control is unclear. The aim of this study was to examine the relationship between PP and MBP and BP control. We obtained home BP measurements for 117 patients aged 40-75 years with either office systolic BP (SBP) >or= 140 mmHg or office diastolic BP (DBP) >or= 90 mmHg. Patients were treated with 1 to 2 antihypertensive drugs for 6 months to achieve home SBP < 135 mmHg and home DBP < 85 mmHg. At follow-up, 72 patients were taking a single drug with good BP control, 23 were taking two drugs with good BP control, and 22 were taking two drugs without good BP control. Although office SBP and DBP at baseline were similar in the three groups, home SBP and DBP at baseline in the single drug group were lowest among the three groups (P < 0.01). Home MBP at baseline in the single drug group was lowest among the three groups (P < 0.01). Home PP at baseline was highest in the two-drug without good control group (P < 0.001). In multivariate logistic regression analysis, only home MBP at baseline was significantly correlated with a lack of BP control. Home MBP rather than home PP is associated with achieving adequate BP control.     

Arterialized ear lobe blood samples for blood gas tensions.

The accuracy of arterialized blood samples both at rest and during exercise is described in comparison to simultaneous arterial blood samples. The technique was found to be reliable and sufficiently accurate for clinical exercise testing, with no significant differences for Po2 or Pco2 between the two methods.     

Silk-based blood stabilization for diagnostics

Advanced personalized medical diagnostics depend on the availability of high-quality biological samples. These are typically biofluids, such as blood, saliva, or urine; and their collection and storage is critical to obtain reliable results. Without proper temperature regulation, protein biomarkers in particular can degrade rapidly in blood samples, an effect that ultimately compromises the quality and reliability of laboratory tests. Here, we present the use of silk fibroin as a solid matrix to encapsulate blood analytes, protecting them from thermally induced damage that could be encountered during nonrefrigerated transportation or freeze–thaw cycles. Blood samples are recovered by simple dissolution of the silk matrix in water. This process is demonstrated to be compatible with a number of immunoassays and provides enhanced sample preservation in comparison with traditional air-drying paper approaches. Additional processing can remediate interactions with conformational structures of the silk protein to further enhance blood stabilization and recovery. This approach can provide expanded utility for remote collection of blood and other biospecimens empowering new modalities of temperature-independent remote diagnostics.Blood contains a variety of proteins, enzymes, lipids, metabolites, and peptides, which can be interrogated as biomarkers for health screening, monitoring, and diagnostics. The integrity of these blood components and thus the quality of information attained from their analysis is determined by the storage conditions from sampling until analysis, or the so-called pre-analytical phase (1, 2). This phase often includes time-consuming processing steps and the requirement for a continuous cold storage. Without temperature regulation, blood-derived biospecimens degrade quickly, accounting for up to 67% of all laboratory testing errors (2, 3). Further, when blood-derived materials are frozen, decreases in thermodynamic free energy and unfavorable ice crystal–protein interactions (4) can occur during subsequent thawing (5, 6), which can further compromise analyte integrity as a gold-standard methodology.As an alternative route, blood and blood derivatives can be dried via newer approaches such as isothermal vitrification (7), lyophilization (8), or on silica chips (9). Isothermal vitrification and lyophilization are inherently resource-intensive techniques and thus not suitable for field use. Silica chips are designed for enrichment of selected fractions of the low-molecular-weight serum proteome, but are not broadly protective at elevated temperature (10). An inexpensive alternative used since the 1960s are dried blood spots (DBS) (11), a paper card system which captures blood components among cellulose fibers as the water phase evaporates. These drying measures decrease sample weight by >90%, thus decreasing transport burden, and in theory can enhance long-term sample stability by decreasing water-dependent analyte degradation caused by hydrolysis and enzyme activity (12). Unfortunately, DBS stored in challenging environments (i.e., elevated temperatures and humidity) quickly lose their protective capacity (13, 14). Indeed, years of field research supported by the Centers for Disease Control has shown that DBS on-card drying approaches do not fully safeguard all blood analytes (15). Piloting DBS cards for the National Health and Nutrition Examination Survey revealed unreliable recovery of cholesterol markers, which was attributed to oxidative stress (16). Thus, although newborn screening programs have relied heavily on DBS (17), cold storage of DBS is still considered a requirement for use, and this fact has limited widespread adoption of dried sample preservation formats to solve worldwide cold chain issues.A new class of biomaterials based on the silk fibroin protein is being considered to address a wide range of stabilization challenges, from labile enzymes (18) to antibodies (19). Silk fibroin (hereafter referred to as silk) is a high-molecular-weight amphiphilic protein (20). Silk is generated in an aqueous state and is thus readily miscible with both simple protein solutions as well as complex fluids such as whole blood (21). As a protein polymer, silk can be processed into a variety of mechanically robust formats including films (18) and gels (22). Self-assembly of silk into solid structures can be initiated through physicochemical factors (23) or by water removal (21, 24). Although these particular features are not specific to silk, we and others have examined similar excipients for use as stabilizing matrices such as albumin, collagen, gelatin, and sugars. Along with immunogenicity and manufacturing sustainability concerns with collagen and gelatin, materials formed from these biopolymers are not as mechanically robust as silk and have lower glass transition temperatures. Although both albumin and sugars are used frequently in freeze-dried pharmaceutical formulations, neither can form self-standing constructs. Taken together, the drawbacks of common excipients and the DBS technology explain the scarcity of a material ideal for stabilizing dried biospecimens in limited resource settings.We hypothesized that the unique features of silk protein would offer stabilization of blood components to aid in remote sample retrieval and transport. To test this hypothesis, we identified silk solution processing characteristics that enhanced the solubility characteristics of final dried silk-containing matrices after storage, which in turn enabled enhanced recovery of blood-based analytes. We then tested both the silk stabilizers alone as well as silk/blood mixtures under long-term storage conditions at elevated temperatures to simulate field conditions. In some circumstances, reduced recovery of analytes in the presence of silk was ameliorated by the addition of salts that reduced silk hydrogen bonding, thus extending known mechanisms of silk stabilization (19, 25, 26). These findings should translate to technologies for remote and refrigerator-free sample procurement, either as a surrogate method for a variety of outpatient blood collection needs (i.e., screening and chronic disease monitoring), or to serve researchers/clinicians who are far from centralized testing facilities. Examples of the latter case include large-scale epidemiologic studies, multicenter reference interval studies, remote pharmacological trials, and other nonclinical studies.