Heterogeneity of RNP and Sm autoantigens in relation to the cell sources and the activated state of the cells

Summary The extracts of rabbit thymus (RTE), HeLa cells, human histiocytic lymphoma cell line U-937, human promyelocytic cell line HL-60, Ehrlich ascites tumor cells (EACs), and peripheral white blood cells (WBCs) were tested for their composition, molecular weight, and amount of Sm and RNP autoantigens on immunoblotting. The molecular weight of the so-called 68 kDa U1 RNP antigen, which is associated with mixed connective tissue disease (MCTD), was 64.5 kDa in RTE, 62.5 kDa in HeLa cells and HL-60 cells, and 59 kDa in WBCs. Surprisingly, in both WBCs and U-937 cells, the main protein band bearing the 68 kDa U1 RNP antigenic determinants was 30.5 kDa in molecular weight, which was confirmed using antibodies purified by affinity chromatography. After stimulation with phytohemagglutinin (PHA), there was in the human lymphocytes a diminished amount of the 30.5 kDa protein and simultaneously an increased synthesis of several proteins of higher molecular weight, especially the 57 kDa protein bearing the 68 kDa antigenic determinants. The concentrations of the A, B/B, C, D, and E proteins also increased with PHA stimulation. Our results indicate that the expression of Sm and RNP autoantigens may depend on the cell source as well as the activated state of cells. These differences should be taken into consideration in the detection of anti-RNP and anti-Sm antibodies by immunoblotting.     

间接免疫荧光法和免疫印迹法联合检测抗聚角蛋白微丝蛋白抗体对类风湿关节炎的诊断价值

目的探讨用间接免疫荧光(IIF)和免疫印迹(IB)两种方法联合检测抗聚角蛋白微丝蛋白抗体(AKA/AFA)对类风湿关节炎(RA)诊断的价值。方法对401份血清标本进行检测,包括185例RA,164例非RA的风湿病患者,52名健康对照。以Wistar大鼠食管中段角质层冰冻切片为底物,用IIF法检测抗角蛋白抗体(AKA/AFA),以人乳腺癌上皮提取的聚角蛋白微丝蛋白为抗原,用IB法检测AFA。结果IIF法、IB法及两种方法联合检测AFA的敏感性分别为36.7%、46.5%、56.2%,特异性分别为94.5%、95.7%、93.3%,两种方法联合检测阳性预测值90.4%,阴性预测值65.4%。联合检测较IIF法单独检测敏感性增加20%,经χ2检验差异有显著性(P<0.01);联合检测较IB法单独检测敏感性增加10%,经χ2检验差异无显著性(P=0.058);而联合检测没有降低其特异性(P>0.05;P>0.05)。在164例非RA病人对照组中,两种方法联合检测AFA阳性11例,1年追踪观察结果显示,其中3例符合1987年ACR的RA的诊断标准4条以上,另外3例符合3条。结论AFA是RA的特异性血清学标记,IIF法和IB法检测AFA有相似的诊断价值,特异性高而敏感性低;两种方法检测结果相关,但不重叠;联合使用两种方法检测AFA有助于提高RA诊断的敏感性。     

血小板激活因子与支气管哮喘

支气管哮喘是由多种炎症细胞和炎症介质介导的慢性气道炎症。血小板激活因子（platelet-activating factot,PAF）是一种功能强大的脂类介质,主要和细胞膜上的PAF受体（PAF-Receptor,PAFR）结合介导生物学反应,在哮喘发生发展过程中具有重要意义。     

缺血性结肠炎的临床特点以及血小板功能的研究

背景:近年缺血性结肠炎(IC)的发病率明显增加,尤其是重症IC,早期无特殊表现,可引起结肠坏死、穿孔,甚至死亡。目的:探讨IC患者的临床特点以及血小板功能的变化。方法:将2009年1月～2012年1月同济大学附属第十人民医院87例IC患者分成重症IC组和轻症IC组,并选取30名健康者作为正常对照。分析轻症IC和重症IC的临床特点,并检测血小板激活复合物(PAC)-1和血小板α-颗粒膜糖蛋白(CD62P)、血小板平均体积(MPV)、血小板分布宽度(PDW)和血小板计数(PLT)。结果:与轻症IC组相比,重症IC组右半结肠发病率显著升高(P<0.05),左半结肠发病率显著降低(P<0.05),死亡率显著升高(P<0.05),腹痛、腹泻、便血、全结肠发病率无明显差异(P>0.05)。IC组PAC-1和CD62P、MPV、PDW均显著高于正常对照组(P<0.05),PLT无明显差异(P>0.05)。重症IC组PAC-1、CD62P、MPV、PDW显著高于轻症IC组(P<0.05),PLT显著低于轻症IC组(P<0.05)。结论:右半结肠病变、血小板活化以及参数的变化可能与重症IC患者密切相关,作为危险因素早期应引起临床医师的高度重视。     

Antinuclear antibodies in patients with systemic lupus erythematosus: a comparison of counterimmunoelectrophoresis and immunoblotting

Summary Traditionally, the method used mostly to identify antinuclear antibody (ANA) specificities is the counterimmunoelectrophoresis technique (CIE), in which a salt extract of rabbit thymus powder (so-called extractable nuclear antigen or ENA) serves as the source of antigen. Recently, the immunoblotting technique (IBT) has been introduced in the serology of antinuclear antibodies. A nuclear extract of HeLa cells is generally used as antigen in this method. In this paper, we compared both methods using sera of patients with active systemic lupus erythematosus (SLE). Only anti-Sm, anti-RNP, and Anti-SSB were taken into consideration, as the former technique only allowed the identification of these specificities. Within these restrictions, we found that, of 77 patients with SLE, 21 had CIE-detectable antibodies in their circulation and 29 IBT-detectable antibodies. Anti-RNP and anti-SSB were detected more frequently with the CIE than with the IBT; anti-Sm, on the other hand, was detected more frequently with the IBT than with the CIE. Several significant correlations were found between incidences of measured antibody specificities and disease features. The presence of anti-RNP (both if measured with the IBT or with the CIE) was found to be negatively correlated with nephritis. If measured with the IBT, the presence of anti-Sm correlated negatively with hematological disorders, and the presence of anti-SSB correlated positively with renal involvement. Only if measured with the CIE did the presence of anti-SSB correlate negatively with central nervous system disorders.     

Status of Platelet Collection and Platelet Transfusion

Abstract: Platelet product derived from single donor plateletpheresis is required to reduce the risks of adverse reactions by blood transfusion. The objectives of this study are to evaluate the status of platelet collection and its efficacy by various kinds of plateletpheresis equipment and to assess the achievement of platelet transfusion by platelet product derived from a single donor. Since the blood centers have introduced some kinds of efficient plateletpheresis equipment, large units of platelet products have been supplied mainly for the patients. Amicus and CCS might be preferable plateletpheresis machines because of their collection efficiencies and wider indication for donors. The average number of donors of platelet product per patient has recently reached nearly 1.0, and around 90% of patients have received platelet product derived from a single donor in the recent several years. However, platelet transfusion derived from a single donor has not yet been completely achieved. Each regional blood center should seriously consider the efficacy of each plateletpheresis equipment and arrange the equipment to collect platelets more effectively to achieve platelet transfusion from a single donor.     

Platelet surface antigens: Analysis by monoclonal antibodies

Summary Monoclonal antibodies were produced against human platelets. Four antibodies (PA1, PA2, PA3 and PA4) reacted specifically with platelets and megakaryocytes, but not with peripheral blood lymphocytes, granulocytes, erythrocytes or monocytes. The antibodies belonged to the mouse IgG subclass 2a (PA1, PA2, PA3), or 1 (PA4) respectively. PA1 and PA4 did not precipitate, their antigens have not yet fully been characterized. PA3 was directed against the glycoprotein (Gp) complex IIb/IIIa; PA2 precipitated Gp IIb/IIIa, and, in addition, Gp Ia. PA4 revealed specificity against the human platelet alloantigen Zw(a).     

Platelet Function Analysis by Flowcytometry in Thrombocytopenic Trauma Patients

Hemostasis is dependent on sufficient quantity and quality of circulating functional platelets. Platelet function in trauma patients with thrombocytopenia and its impact on the clinical outcome is not adequately explored. Whether platelet dysfunction has a role in the pathogenesis of acute traumatic coagulopathy needs to be studied. Blood samples were collected from 70 thrombocytopenic trauma patients before transfusing platelets and assessed for platelet activation and platelet aggregation using flowcytometry. Primary outcome was in-hospital mortality. Platelet dysfunction was identified in 57.1% of thrombocytopenic trauma patients. A weak inverse correlation between percentage of activated platelets and APTT was observed (Spearman coefficient − 0.25, p = 0.03). A sensitivity and specificity of 66.6% was achieved for a cut off of ≤ 6.5% of platelet activation post trauma with ROC-AUC of 0.658 for identifying coagulopathy. No correlation with mortality however was observed (p > 0.05). Platelet dysfunction had a weak association with coagulopathy suggesting limited contribution of platelet dysfunction in pathogenesis of acute traumatic coagulopathy and warrants further research.     

New parameter in diagnosis of acute appendicitis:Platelet distribution width

AIM:To investigate the diagnostic accuracy of the mean platelet volume and platelet distribution width in acute appendicitis.METHODS:This retrospective,case-controlled study compared 295 patients with acute appendicitis(Group?Ⅰ),100 patients with other intra-abdominal infections(GroupⅡ),and 100 healthy individuals(GroupⅢ)between January 2012 and January 2013.The age,gender,and white blood cell count,neutrophil percentage,mean platelet volume,and platelet distribution width values from blood samples were compared among the groups.Statistical analyses were performed using SPSS for Windows 21.0 software.In addition,the sensitivity,specificity,positive and negative predictive values and likelihood ratios,and diagnostic accuracy were calculated.RESULTS:The mean ages of patients were 29.9±12.0years for Group?Ⅰ,31.5±14.0 years for GroupⅡ,and30.4±13.0 years for GroupⅢ.Demographic features such as age and gender were not significantly different among the groups.White blood cell count,neutrophil percentage and platelet distribution width were significantly higher in Group?Ⅰ?compared to groupsⅡandⅢ(P0.05).Diagnostically,the sensitivity,specificity and diagnostic accuracy were 73.1%,94.0%,and 78%for white blood cell count,70.0%,96.0%,and 76.0%for neutrophil percentage,29.5%,49.0%,and 34.0%for mean platelet volume,and 97.1%,93.0%,and 96.0%for platelet distribution width,respectively.The highest diagnostic accuracy detected was for platelet distribution width between Group?Ⅰ?and GroupⅢ(P0.01).CONCLUSION:Platelet distribution width analysis can be used for diagnosis of acute appendicitis without requiring additional tests,thus reducing the cost and loss of time.     

血小板活化与动脉粥样硬化病变相关性的研究进展

随着当今社会心脑血管病发病率的不断攀升，心脑血管疾病的共同病理基础——动脉粥样硬化（atherosclerosis，AS）引起广大医务工作者和医学科研工作者的高度关注。AS是一个与内皮细胞损伤、脂质紊乱、血流动力学异常有关的、极其复杂的慢性炎症过程。     

Platelet membrane glycoproteins and their function: An overview

Summary The membrane glycoproteins (GP) of human platelets act as receptors that mediate two important functions, adhesion to the subendothelial matrix and platelet-platelet cohesion, or aggregation. Many of these glycoprotein receptors exist as noncovalently linked heterodimers, including those that belong to the supergene family of adhesion receptors called the integrins. Human platelets contain at least five members of this integrin family, including a collagen receptor (GP Ia-IIa; ₂, ₁), a fibronectin receptor (GP Ic-IIa; ₅, ₁), a laminin receptor (GP Ic-IIa; ₆, ₁), a vitronectin receptor (VnR; _v, ₃), and a promiscuous, activation-dependent receptor that is thought to be the receptor most responsible for fibrinogen-dependent, platelet-platelet cohesion (GP IIb-IIIa; _IIb, ₃). Some, but not all, of the integrins bind to a tripeptide sequence, arginine-glycine-aspartic acid (RGD), on the adhesive proteins. In addition to the integrins, platelets contain other membrane glycoproteins: GP Ib-IX, a receptor for von Willebrand factor, which is thought to be the receptor most responsible for platelet adhesion to the subendothelial matrix in a flowing system; GP V, which may be associated with GP Ib-IX and whose function remains unknown; and GP IV (GP IIIb), which functions as a receptor for thrombospondin and collagen.Presented at the International Workshop on ITP, August 26 and 27, 1988, Lucerne, Switzerland     

血小板活化与心血管疾病

血小板活化在心血管疾病的发生发展中起着非常重要的作用。本文对血小板活化的分子标志物与心血管疾病的关系进行综述。     

A Comparative Assessment of Quality of Platelet Concentrates Prepared by Buffy Coat Poor Platelet Concentrate Method and Apheresis Derived Platelet Concentrate Method

Many blood centres in country don’t have costly apheresis technology and rely heavily on the platelet production from whole blood donation. We conducted this study with the aim to compare the quality of platelet concentrates (PC) prepared by Buffy Coat derived (BC-PC) and apheresis derived platelet concentrate (Apheresis-PC). Our objective was to collect data by analysis of platelet concentrates prepared by BC-PC methods and Apheresis-PC methods in respect of swirling, volume, platelet count, WBC count and pH of the PC units and elaborate on the quality parameters. Tertiary Care Hospital and Medical College. We assessed a total of 200 BC-PC and 200 Apheresis-PC for their in vitro quality by observing swirling, volume of PC, platelet count/unit, WBC count/unit and pH, to see if they satisfy the recommended quality criteria. Data was analyzed using appropriate statistical technique under the guidance of biostatistician. Apheresis-PC units showed better swirling than BC-PC units (Chi square test; P < 0.05). There was a significant difference in proportion of units satisfying the required volume QC between the two methods (Chi-square test; P < 0.05). Apheresis-PC showed better adherence to the physiological pH values (Student’s unpaired t test; P < 0.05). The units of BC-PC and Apheresis-PC did not show significant difference in proportion of units satisfying the Platelet count per unit and residual WBC count per count (Chi square; P 0.203 and 0.617 respectively). There was comparable adherence to QC requirement for platelet count and WBC contamination in two methods. BC-PC were found to be adhering lesser to QC parameters for swirling, volume and pH, but found to be in required QC limits. BCPC can be used effectively in the majority of thrombocytopenic patients in resource poor setting.     

Platelet dysfunction in myelodysplastic syndromes: a clinicopathological study

Forty-eight patients with myelodysplastic syndromes and a platelet count greater than 80 x 10(9)/L were the subjects of a study of platelet function. A whole-blood platelet lumi-aggregometer was used for simultaneous measurement of platelet aggregation by the impedance method and of adenosine triphosphate-dense granule release. The results were correlated with skin bleeding time and episodes of clinical bleeding or thrombosis. Thirty-five patients had at least 1 abnormal result indicating platelet hypoactivity; 7 patients had mixed platelet hypoactivity and hyperactivity; and 4 patients had platelet hyperactivity. Only 2 patients had normal results. There was good correlation between platelet hypoactivity and prolonged skin bleeding time (P = .005); however, several patients with platelet hypoactivity had normal skin bleeding times. This finding suggested that whole-blood platelet aggregation studies may be more sensitive than bleeding time in identification of patients at risk of bleeding. Clinical hemorrhage was frequent (32 patients) in this cohort despite platelet counts greater than 100 x 10(9)/L. This finding indicated platelet hypofunction was clinically important. In contrast, only 2 of the 13 patients with thrombotic events had evidence of platelet hyperactivity, suggesting that other clinical factors are probably more important determinants of thrombosis. These observations confirm that platelet dysfunction is common in patients with myelodysplastic syndromes and suggest a useful role for routine whole-blood platelet aggregation studies to identify patients at risk of bleeding.     

Platelet aggregation in atopic dermatitis

Many observations suggest the active role of platelets in allergic inflammation. However, this problem is poorly researched in atopic dermatitis. The aim of study was to examine the intensity and velocity of platelet aggregation and a potential relationship with some immunological parameters (total IgE and specific-IgE serum levels) in atopic dermatitis patients. Platelet aggregation was evaluated in 12 subjects with atopic dermatitis and 12 healthy, nonatopic persons, according to the Born method, in a dual-channel aggregometer, in response to three exogenous stimulators (ADP, thrombin and collagen). The intensity and velocity of platelet aggregation and total platelet counts did not differ between the two groups irrespective of the type of extrinsic stimulator used. In contrast to other atopic diseases, in atopic dermatitis platelet aggregation is not impaired.     

The Effects of Desflurane on Human Platelet Aggregation In Vitro

In view of the possible antiplatelet effects of general anesthetics, we investigated the in vitro effects of desflurane, a new inhalation agent, on platelet aggregation. For 15 patients who underwent elective operations, blood was sampled with desflurane induction before and after anesthesia but prior to surgery so that platelet aggregation in the drawn blood could be tested before desflurane anesthesia and again after exposure to the anesthetic. Platelet aggregation was measured with a whole-blood aggregometer. Adenosine diphosphate (ADP), collagen, and ristocetin were used as aggregating agents. Our results showed that aggregation in response to ADP, collagen, or ristocetin was not inhibited in patients who received desflurane anesthesia. This study with an in vitro model showed that desflurane had no influence on platelets in clinically relevant doses.     

Platelet Indices and Their Kinetics Predict Mortality in Patients of Sepsis

Platelet indices are inexpensive, easily accessible parameters and potentially useful prognostic indicators in sepsis. In this study we explore the differences in platelet indices and their kinetics between sepsis survivors and non-survivors. A retrospective cohort-study of 97 cases of culture-positive sepsis at a tertiary-care center in North India. Demographics, clinical and laboratory parameters at admission were assessed. Platelet count (PLT), mean-platelet-volume (MPV), platelet-distribution-width (PDW) and plateletcrit (PCT) on admission, and third, fifth and last days of hospitalization were analyzed. Fractional change in platelet indices (ΔMPV_72h, ΔPDW_72h, ΔPCT_72h, and ΔPLT_72h) by day-3 were calculated. Unpaired and paired t-tests were used to compare survivors with non-survivors, and to study the change in platelet indices with time. Logistic regression was used for multivariate analysis. ROC-curves and optimum cut-offs to predict mortality were obtained. There were 64 survivors. Non-survivors had significantly higher ΔMPV_72h, ΔPDW_72h, day-1 MPV and PDW, and lower ΔPLT_72h. MPV and PDW increased, and PLT decreased with time among non-survivors. Trends were reversed in survivors. Only MPV and PDW showed significant change by day-3. Both were independent predictors of mortality on multivariate analysis, alongside ΔMPV_72h and ΔPLT_72h. On ROC analysis, MPV, PDW, ΔMPV_72h, ΔPDW_72h and ΔPLT_72h effectively predicted mortality. Cut-off for MPV was 10.25 fL (sensitivity = 93.9%, specificity = 60.9%), and PDW, 12.6% (sensitivity = 84.8%, specificity = 51.6%). A rise in MPV and a fall in PLT was associated with mortality in this study. MPV and PDW values at admission are effective predictors of mortality and may be used in conjunction with traditional parameters.