RNA恒温扩增实时荧光检测技术对结核性胸腔积液的诊断价值

目的 探讨RNA恒温扩增实时荧光检测技术(simultaneous amplification and testing, SAT-TB)对结核性胸腔积液的诊断价值。方法 选取2014年6月至2016年6月聊城市传染病医院收治的有胸腔积液的患者210例作为研究对象,其中143例临床诊断为结核性胸膜炎,作为结核性胸膜炎组;其余67例患者作为对照组。应用涂片法、改良罗氏培养法、SAT-TB法检测研究对象胸腔积液标本,比较各检测方法的检测效能。结果 SAT-TB检测的敏感度、特异度、阳性预测值、阴性预测值分别为36.36%(52/143)、98.51%(66/67)、98.11(52/53)、42.04%(66/157)。SAT-TB检测的敏感度明显高于涂片法[3.50%(5/143)]及罗氏培养法[20.28%(29/143)],差异均有统计学意义(χ ²=19.08,P=0.021;χ ²=9.12,P<0.01)。SAT-TB法检测完成时间为1~2h,罗氏培养法完成时间为6~8周。 结论 SAT-TB法能快速检测胸腔积液中的结核分枝杆菌,敏感度高于涂片法和罗氏培养法。     

DNA微阵列芯片法检测耐药结核分枝杆菌的临床应用价值研究

目的 评价DNA微阵列芯片法检测结核分枝杆菌及其对异烟肼和利福平耐药的检测效能。 方法 收集2011年1月至2017年5月间在江苏省灌云县疾病预防控制中心登记的814例涂阳肺结核患者的痰标本。利用传统罗氏培养法及比例法药物敏感性试验(简称“药敏试验”)和DNA微阵列芯片法,同时对患者的痰标本进行结核分枝杆菌检测,并检测其对异烟肼和利福平的耐药情况;分别以传统罗氏培养及比例法药敏试验为标准,评价DNA微阵列芯片法的检测效能。 结果 DNA微阵列芯片法对涂阳肺结核患者的结核分枝杆菌检出率为86.1%(701/814),高于传统罗氏培养法的82.4%(671/814),差异有统计学意义(χ ²=6.81,P<0.05)。以传统罗氏培养法为标准,DNA微阵列芯片法检测涂阳患者结核分枝杆菌的敏感度和特异度分别为92.4%(620/671)和43.4%(62/143),Kappa=0.39,阳性预测值和阴性预测值分别为88.4%(620/701)和54.9%(62/113)。以药敏试验为标准,对有完整的异烟肼和利福平耐药检测结果的620例患者进行分析,DNA微阵列芯片法检测初治涂阳患者是否对异烟肼与利福平耐药的敏感度分别为78.7%(37/47)和84.6%(22/26),阳性预测值分别为69.8%(37/53)和73.3%(22/30);检测复治涂阳患者是否对异烟肼与利福平耐药的敏感度分别为71.9%(23/32)和89.3%(25/28),阳性预测值分别为85.2%(23/27)和89.3%(25/28)。 结论 DNA微阵列芯片法对结核分枝杆菌的检出率高于传统罗氏培养;对结核分枝杆菌对异烟肼和利福平耐药性检测效果理想,具有较好的应用价值。     

恒温扩增荧光检测技术在基层结核病实验室的应用价值

目的 探讨在基层结核病实验室采用恒温扩增荧光检测技术检测可疑肺结核患者痰标本诊断结核病的价值。 方法 搜集河南省4个项目点县级结核病实验室2014—2015年期间可疑肺结核患者的痰标本4242例,分别进行痰涂片、痰培养和恒温扩增荧光检测技术检测,比较恒温扩增荧光检测技术和传统痰涂片、痰培养方法的敏感度、特异度等。计数资料采用χ ²检验,以P<0.05为差异有统计学意义。 结果 纳入的4242例患者中,痰涂片检出阳性者351例,阳性检出率为8.21%(351/4276);痰培养检出阳性者576例,阳性检出率为13.47%(576/4276);恒温扩增荧光检测技术检出阳性者733例,阳性检出率为17.14%(733/4276)。3种检测技术的阳性检出率比较,差异有统计学意义(χ ²=153.412,P<0.001)。以痰培养试验结果为标准,恒温扩增荧光检测技术的敏感度和特异度分别为86.81%(500/576)、93.64%(3433/3666);阳性预测值为68.21%(500/733),阴性预测值为97.83%(3433/3509),与痰培养有较高的一致性(Kappa值为0.722)。痰涂片检测的敏感度为57.29%(330/576),特异度为99.43%(3645/3666),阳性预测值为94.02%(330/351),阴性预测值为93.68%(3645/3891);Kappa值为0.679。痰涂片与恒温扩增荧光检测技术检测痰标本的敏感度比较,差异有统计学意义(χ ²=153.336,P<0.001)。 结论 恒温扩增荧光检测技术检测的敏感度和特异度均明显高于传统的痰涂片,且其具有检测快速、操作简便等优势,便于在我国基层结核病实验室中推广应用。     

免疫组织化学及PCR技术在淋巴结结核病理诊断中的应用价值

目的 探讨免疫组织化学(immunohistochemistry,IHC)及PCR技术在淋巴结结核病理学诊断中的应用价值。方法 收集首都医科大学附属北京胸科医院病理科保存的2012年1月至2013年7月之间的48例手术根治切除淋巴结结核患者(结核组)和21例非淋巴结结核患者(非结核组)的石蜡包埋组织标本,分别应用IHC染色、荧光定量PCR和抗酸染色法对标本进行检测,以临床最后诊断为金标准,比较各方法的检测效能。结果 IHC染色、荧光定量PCR及抗酸染色检测的敏感度分别为52.1%(25/48)、60.4%(29/48)及27.1%(13/48);IHC染色和荧光定量PCR检测敏感度均高于抗酸染色,差异均有统计学意义(χ ²值分别为 6.27、10.84,P值分别为0.012、0.001);而IHC染色与荧光定量PCR比较,敏感度差异无统计学意义(χ ²=0.68,P=0.411)。IHC染色、荧光定量PCR及抗酸染色法检测非结核组结果均为阴性,特异度均为100%(21/21)。IHC染色、荧光定量PCR及抗酸染色法的阴性预测值分别为47.7%(21/44)、52.5%(21/40)、37.5%(21/56);符合率分别为66.7%(46/69)、72.5%(50/69)、49.3%(34/69),IHC染色、荧光定量PCR均优于抗酸染色法。 结论 IHC染色、荧光定量PCR与抗酸染色法相比,可提高阳性检出率,在淋巴结结核的病理学诊断中具有良好应用价值。     

KOD DNA聚合酶荧光PCR技术在肺结核诊断中的应用评价

目的 评估基于KOD DNA聚合酶的荧光PCR技术在肺结核诊断中的临床应用价值。方法 采集2019年10月至2020年4月疑似肺结核的住院患者痰标本,进行涂片抗酸染色、MGIT960液体培养、KOD DNA聚合酶荧光PCR和Taq DNA聚合酶荧光PCR检测。以临床诊断结果为参照,MGIT960液体培养法为金标准,荧光PCR与Taq DNA聚合酶荧光PCR法比较,评价KOD DNA聚合酶荧光PCR法检测MTB的效能。结果 共对337例临床样本进行检测,MGIT960液体培养法、Taq DNA聚合酶荧光PCR和KOD DNA聚合酶荧光PCR检测MTB的敏感度分别为71.56% (156/218)、76.15% (166/218) 和76.61% (167/218)。KOD DNA聚合酶荧光PCR与MGIT960液体培养检测敏感度差异无统计学意义 (χ²=1.445,P=0.229>0.05)。KOD DNA聚合酶荧光PCR检测MTB的敏感度和特异度分别为92.31% (144/156)和86.39% (146/169),涂阴患者中检测敏感度和特异度分别84.21% (64/76)和88.48% (146/165)。结论 KOD DNA聚合酶荧光PCR检测MTB敏感度和特异度较高,能够为临床诊断肺结核提供依据,操作简便、快速,适合在我国各级结核病实验室推广。     

分子病理学诊断颈部淋巴结结核及其耐药性的应用价值

目的 评价分子病理学方法诊断颈部淋巴结结核及其耐药性的临床应用价值。方法 搜集2010年3月至2013年10月首都医科大学附属北京胸科医院病理科收治的符合纳入标准(临床症状和体征均符合颈部淋巴结结核、抗结核药物治疗均有效)的全部97例颈部淋巴结结核患者(结核组);以及符合纳入标准(通过病理学或临床检测结果明确诊断为其他淋巴结疾病)的全部20例其他淋巴结病变患者(非结核组)的石蜡包埋标本。所有标本以萋-尼(Z-N)抗酸染色法查找抗酸杆菌,荧光定量聚合酶链式反应(FQ-PCR)检测结核分枝杆菌特异基因序列IS6110;以临床最后诊断为标准,比较两种方法的检测效能;并对FQ-PCR检查结果为阳性且结核分枝杆菌DNA含量满足耐药突变检测下限的标本,以探针熔解曲线法检测利福平、异烟肼耐药相关基因突变情况。结果 以临床最后诊断为标准,抗酸染色和FQ-PCR检测结核组的敏感度分别为22.7%(22/97)和67.0%(65/97);FQ-PCR技术检测敏感度明显高于抗酸染色法,差异有统计学意义(χ²=38.53,P<0.001)。抗酸染色和FQ-PCR检测非结核组标本均为阴性,特异度均为100.0%(20/20)。抗酸染色和FQ-PCR的阳性预测值分别为100.0%(22/22)和100.0%(65/65),阴性预测值分别为21.1%(20/95)和38.5%(20/52),符合率分别为35.9%(42/117)和72.6%(85/117)。对41例FQ-PCR检查结果为阳性且结核分枝杆菌DNA含量满足耐药突变检测下限的患者标本进行结核分枝杆菌耐药基因突变检测,利福平和异烟肼可评估标本分别为10份(例)和27份(例),其中利福平耐药1份(例),异烟肼耐药13份(例)。 结论 分子病理学诊断技术在颈部淋巴结结核石蜡包埋标本中检测结核分枝杆菌DNA的敏感度和特异度较高,并且能筛查可能的耐药患者,可为颈部淋巴结结核的正确诊断与合理化治疗提供依据。     

三种快速检测技术诊断早期结核性脑膜炎的评价

目的 评价3种快速检测技术在早期结核性脑膜炎诊断中的应用价值。方法 采用离心涂片抗酸染色法、改良抗酸染色法、GeneXpert MTB/RIF技术(简称“GeneXpert技术”)对2016年8月至2018年6月河北省胸科医院和石家庄市第五医院收治的根据临床表现、影像学及实验室检查等临床确诊的45例结核性脑膜炎、42例非结核性脑膜炎患者的脑脊液标本进行分枝杆菌检测,并对结果进行分析。采用SPSS 19.0软件进行统计学分析,率的比较采用χ ²检验、校正χ ²检验,以P<0.05为差异有统计学意义。结果 以临床诊断为标准,45例结核性脑膜炎患者脑脊液分别应用离心涂片抗酸染色法、改良抗酸染色法、GeneXpert技术检测分枝杆菌的敏感度分别为4.44%(2/45)、88.89%(40/45)、35.56%(16/45);依次两两比较,差异均有统计学意义(χ ²值分别为64.46、13.16、27.23,P值均=0.000)。42例非结核性脑膜炎患者的脑脊液用离心涂片抗酸染色法、改良抗酸染色法、GeneXpert技术检测分枝杆菌均为阴性。3种检测技术检测分枝杆菌的特异度均为100.00%。结论 改良抗酸染色法较离心涂片法及GeneXpert技术检测分枝杆菌阳性率高,具有较好的确诊结核性脑膜炎的价值。     

超声引导下获取标本行病理学与结核相关检测对结核性胸膜炎的诊断价值

目的 比较分析超声引导下胸膜穿刺获取的病理组织及胸腔积液标本在疑似结核性胸膜炎中的诊断价值。方法 搜集2016年1月至2018年5月在西安市胸科医院初次就诊的298例疑似结核性胸膜炎患者,其中临床确诊结核性胸膜炎患者112例,非结核性胸膜炎患者186例。所有患者均通过超声引导下胸膜穿刺获取病理组织和胸腔积液标本,对活检组织进行病理学切片检查(简称“病理检查”),胸腔积液分别进行结核分枝杆菌培养(浓缩集菌法,采用液体培养BACTEC MGIT 960操作系统,简称“MGIT 960培养”)、全自动医用PCR分析系统(GeneXpert MTB/RIF,简称“GeneXpert检测”)和抗酸杆菌染色涂片检查(简称“涂片检查”)。上述各种方法以临床确诊患者为参考标准,得出各自的诊断敏感度、特异度、阳性预测值、阴性预测值、约登指数,以评价各种检测方法诊断结核性胸膜炎的效能。结果 病理检查、MGIT 960培养、GeneXpert检测、涂片检查以临床确诊结果为参考标准的诊断敏感度分别为41.96%(47/112)、73.21%(82/112)、58.93%(66/112)和2.68%(3/112);特异度分别为99.46%(185/186)、100.00%(186/186)、100.00%(186/186)、100.00%(186/186);约登指数分别为0.41、0.73、0.59、0.02。结论 超声引导下胸膜穿刺获取标本采用各种技术与方法进行检测,结果证明胸腔积液标本采用浓缩集菌法进行MGIT 960培养相对其他检测技术与方法具有较好的敏感度、特异度,约登指数最高,具有良好的临床诊断结核性胸膜炎的价值。     

三种实验室诊断技术对结核分枝杆菌复合群检出率及检测费用的比较研究

目的 评估液基夹层杯涂片法(采用集菌法;简称“涂片法”)、L-J固体培养法(简称“L-J培养法”)、结核分枝杆菌复合群核酸检测(采用恒温扩增法;简称“恒温扩增法”)对结核分枝杆菌复合群的检测效能。 方法 采用随机数字表法从湖南省120家结核病定点医院中抽取3家作为研究现场,分别为浏阳市人民医院、醴陵市湘东医院、桃江县人民医院。以3家医院2018年11月1日至12月31日就诊的存在可疑肺结核症状的628例患者为研究对象,对同一份痰标本同时采用涂片法、L-J培养法和恒温扩增法进行检测,分析3种检测方法对结核分枝杆菌复合群阳性检出率的差异;并依据《WS 288—2017 肺结核诊断》的诊断标准,以临床诊断肺结核作为参考标准,计算各种检测方法的敏感度、特异度、阳性预测值、阴性预测值、一致率;再以患者进行每项检测的实际支出费用为准,计算每种方法的检测费用。结核分枝杆菌复合群检出率在3种检测技术间的两两比较采用χ ²检验,检验水准α=0.05/3=0.017。 结果 628例疑似肺结核患者中,临床确诊为肺结核患者153例(24.4%),NTM肺病患者6例(1.0%)。3种技术检测结果显示,涂片法、L-J培养法和恒温扩增法的结核分枝杆菌复合群阳性检出率(排除6例NTM肺病患者)分别为13.5%(84/622)、14.0%(87/622)和12.2%(76/622),涂片法和L-J培养法,L-J培养法和恒温扩增法,涂片法和恒温扩增法之间比较,差异均无统计学意义(χ ²=1.32,P=0.359;χ ²=5.83,P=0.024;χ ²=4.00,P=0.077)。以临床诊断结果作为参考标准,排除6例非结核分枝杆菌肺病患者和32例培养污染的患者,涂片法、L-J培养法和恒温扩增法的敏感度分别为55.2%(80/145)、57.9%(84/145)、50.3%(73/145);特异度分别为99.6%(443/445)、99.3%(442/445)、99.8%(444/445);阳性预测值分别为97.6%(80/82)、96.6%(84/87)、98.6%(73/74);阴性预测值分别为87.2%(443/508)、87.9%(442/503)、86.0%(444/516);一致率分别为88.6%(523/590)、89.2%(526/590)、87.6%(517/590)。3种方法的检测费用,由低到高依次为L-J培养法[317.2元(29500/93)]、涂片法[813.8元(70800/87)]、恒温扩增法[1992.2元(153400/77)]。 结论 涂片法、L-J培养法、恒温扩增法的阳性检出率及其敏感度和特异度均未见差异。平均发现1例病原学阳性结核病患者的检测费用,L-J培养法较低,恒温扩增法较高。     

荧光PCR熔解曲线法检测结核分枝杆菌耐药基因的结果分析

目的 分析和探讨荧光PCR熔解曲线法对结核病的诊断和耐药检测的应用价值。方法 收集2015年9月至2016年12月新疆维吾尔自治区胸科医院的976例疑似结核病患者的痰标本,运用探针荧光PCR熔解曲线法来检测结核分枝杆菌及其对利福平、异烟肼的耐药突变情况。以BACTEC MGIT 960液体培养法及液体药敏试验检测结果为标准,评价探针荧光PCR熔解曲线法鉴定结核分枝杆菌及其耐药突变检测的敏感度、特异度、一致率、Kappa值等。结果 以MGIT 960液体培养结果为标准,荧光PCR熔解曲线法鉴定结核DNA的敏感度为85.44%(135/158),特异度为94.01%(769/818),Kappa值为0.75,诊断符合率为92.62%(904/976)。以MGIT 960液体药敏试验结果为标准,荧光PCR熔解曲线法对异烟肼耐药突变检测的敏感度为83.33%(20/24),特异度为94.59%(105/111),Kappa值为0.76,诊断符合率为92.59%(125/135);荧光PCR熔解曲线法对利福平耐药突变检测的敏感度为95.83%(23/24),特异度为95.50%(106/111),Kappa值为0.86,诊断符合率为95.56%(129/135)。结论 荧光PCR熔解曲线法检测速度快,对利福平和异烟肼耐药突变检测结果具有良好的敏感度和特异度,可用于临床上对结核分枝杆菌利福平和异烟肼耐药情况的快速筛查。     

三种检测技术诊断老年肺结核效能的比较研究

探讨结核分枝杆菌及利福平耐药实时荧光定量核酸扩增(GeneXpert MTB/RIF)技术,发光二极管(light emitting diode,LED)荧光染色法和BACTEC MGIT 960系统液体培养(简称“MGIT液体培养”)诊断老年肺结核的价值。     

Diff Quik staining method for detection and identification of monosodium urate and calcium pyrophosphate crystals in synovial fluids

OBJECTIVE: To evaluate whether the Diff Quik (DQ) staining method might prove useful in identifying monosodium urate (MSU) and calcium pyrophosphate dihydrate (CPPD) crystals on permanent mounted stained slides. METHODS: 27 synovial fluid (SF) samples obtained from the knees of 21 patients with acute CPPD disease and 6 with acute gout were studied. Wet analysis for crystal detection and identification was performed within one hour of joint aspiration. In addition, 16 inflammatory synovial effusions obtained from patients with knee arthritis induced by non-crystalline inflammatory diseases were studied. For each SF, a DQ stained slide was analysed by two of the authors trained in SF analysis. The observers were blinded to the type of crystals present in the SF. Each slide was analysed by compensated polarised as well as transmitted light microscopy. An SF was considered positive if intracellular and/or extracellular crystals were clearly identified. In addition, the observer was asked to identify the type of the crystals using compensated polarised light microscopy. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the DQ staining method were determined. RESULTS: 51 true positive and 28 true negative cases were correctly classified (39 CPPD samples, 12 MSU samples, 28 samples of crystal unrelated arthropathies). Overall, four false positive and three false negative cases were reported. In all the false positive cases, extracellular CPPD crystals were erroneously identified, whereas CPPD crystals present in the SF were not identified in the three false negative cases. All MSU specimens were correctly diagnosed. The overall specificity, sensitivity, and accuracy using DQ stained slides for crystal confirmation were respectively 87.5%, 94.4%, and 91.9%. The PPV was 92.7% and the NPV 90.3%. In particular, the specificity, sensitivity, and accuracy for CPPD detection were 90.9%, 92.9%, and 91.9%, with a PPV of 90.7 and an NPV of 93.0%. All the MSU specimens were correctly identified, providing 100% sensitivity, specificity, accuracy, PPV, and NPV. CONCLUSIONS: Stained preparations of SF, including DQ stained smears, could provide a useful tool for delayed SF analysis suitable for quality controls, including cytological examination and crystals detection and identification.     

抗酸染色全自动显微扫描识别系统的临床应用评价

目的 评价抗酸染色全自动显微扫描系统(AFB-AS)检测肺结核患者痰液标本应用价值。方法 搜集2019年1月至8月于北京结核病控制研究所确诊的462例肺结核患者作为研究对象,每例患者留取3份初诊痰液标本,共计1386份。所有标本均完成萋-尼抗酸染色,采用双盲法使用传统抗酸杆菌染色镜检和AFB-AS检查;每例患者选取2份痰液标本进行分枝杆菌分离培养,共计完成924份;其中1份同时进行GeneXpert MTB/RIF(简称“Xpert”)检测,共计完成462份。比较不同方法检测肺结核患者痰标本结果;以分枝杆菌分离培养结果为参照,分析传统抗酸杆菌染色镜检和AFB-AS检测肺结核患者痰标本的效能;分析传统抗酸杆菌染色镜检和AFB-AS检测均为阳性结果的等级相关性。结果 各方法检测肺结核患者痰标本阳性率从高到低依次为Xpert(69.26%,320/462)、分枝杆菌分离培养(43.61%,403/924)、AFB-AS(43.22%,599/1386)、传统抗酸杆菌染色镜检(38.24%,530/1386)。AFB-AS检测痰标本阳性率明显高于传统抗酸杆菌染色镜检,差异有统计学意义(χ²=67.015,P<0.01)。AFB-AS与传统抗酸杆菌染色镜检判读阳性结果等级的相关系数为0.954。以分枝杆菌分离培养结果为参照,AFB-AS检查肺结核患者痰标本敏感度为94.29%(380/403)、特异度为90.40%(471/521)、阳性预测值为88.37%(380/430)、阴性预测值为95.34%(471/494),Kappa值为0.841。结论 AFB-AS检测肺结核患者痰液标本具有较好的应用价值,检验性能能够满足实施萋-尼抗酸染色查找抗酸杆菌项目的要求。     

实时荧光核酸恒温扩增检测技术辅助诊断肺外结核的临床价值

目的 探讨实时荧光核酸恒温扩增检测技术(simultaneous amplification and testing,SAT)辅助诊断肺外结核的价值。 方法 收集2016年1月至2017年12月期间重庆市公共卫生医疗救治中心结核科、普通外科与骨科收治的482例患者肺外样本(主要为病变部位的脓液或手术取出物),根据患者病历记录的临床诊断分为肺外结核(试验组,433例)和排除结核病的其他疾病(对照组,49例)。所有标本同步采用培养法(联合罗氏培养法和BACTEC MGIT 960液体培养法两种方法,只要其中一种培养阳性就视为“培养法”结果为阳性)和SAT检测结核分枝杆菌,并对培养法阳性、SAT检测结果阴性的标本进行菌种鉴定。分别与培养法、患者临床诊断比较,并分析SAT检测的敏感度、特异度和临床辅助诊断肺外结核的价值。 采用SPSS 13.0软件进行分析,计数资料采用χ ²检验,以P<0.05为差异有统计学意义。 结果 试验组127例培养法阳性的标本中TB-SAT检测阳性107例,阴性20例;306例培养法阴性的患者中TB-SAT检测阳性73例,阴性233例。对照组1例标本培养法阳性、TB-SAT检测阴性,其余48例标本培养法与TB-SAT检测均为阴性。以培养法为标准,SAT检测MTB的敏感度、特异度分别是83.6%(107/128)、79.4%(281/354)。与患者临床诊断相比,则培养法的敏感度、特异度分别为29.3%(127/433)、98.0%(48/49);SAT检测MTB的敏感度、特异度分别为41.6%(180/433)、100.0%(49/49)。培养法检测阳性率为29.3%(127/433),SAT法检测阳性率为41.6%(180/433),两者检测阳性率比较,差异有统计学意义(χ ²=14.17,P<0.05)。 结论 SAT检测技术辅助诊断肺外结核具有方便快速、检出率高、敏感度和特异度高等优势,具有较高的临床价值。     

兔须癣毛癣菌感染样本常规诊断与定量PCR诊断的比较研究

目的为探讨须癣毛癣菌快速,敏感,特异的诊断方法.方法 采集患兔临床样本63例,分别进行培养法,镜检法和定量PCR法诊断,比较这些方法的敏感性,特异性,阳性预测值和阴性预测值.结果 显示样本培养法,镜检法和定量PCR法的阳性率分别为65%,73%和86%;与常规方法(培养法和镜检法)相比,定量PCR法敏感性和阴性预测值均为100%,高于培养法(77.35%和45.45%)和镜检法(86.79%和64.17%),而特异性(90.90%对100%~100%)和阳性预测值(90.90%对100%~100%)两种方法无明显差异.结论 培养法特异,但敏感性差,耗时长,有假阴性;镜检快速,但不特异,敏感性低;而定量PCR快速,敏感,又特异,可以替代镜检用于临床样品的诊断,但不能替代培养法.     

Use of a direct fluorescent antibody test for detecting Chlamydia trachomatis cervical infection in women seeking routine gynecologic care

We determined the sensitivity, specificity, and predictive value of a direct fluorescence test for Chlamydia trachomatis infection compared with culture of the endocervix in women seeking routine gynecologic care. Of 527 patients seen in a hospital-based practice, 23 (4.4%) had a positive culture for C. trachomatis. The overall sensitivity of the direct test was 70%, and the specificity was 98%. When five or more endocervical cells were present on the direct test slide, the sensitivity increased to 92%, and the specificity decreased to 96% (P less than .05). When the presence of any columnar epithelial cells, five or more elementary bodies, or both was used as the criteria for accepting specimens, the sensitivity and specificity of the direct test were 80% and 96%, respectively. However, 44% of the specimens would be rejected if these criteria were used. The overall probability that an individual with a positive direct test would have a positive culture was 62%.     

Diff-Quik(R) staining method for detection and identification of monosodium urate and calcium pyrophosphate crystals in synovial fluids

The aim of this study was to evaluate whether DQ could prove useful to identify monosodium urate (MSU) and calcium pyrophosphate dehydrate (CPPD) crystals on permanent mounted stained slides. To this end, we studied 27 synovial fluid (SF) samples obtained from the knees of patients with the pseudogout (n=21) and acute gouty arthritis (n=6). Wet analysis for crystal detection and identification was performed within one hour of joint aspiration. In addition, we studied 16 inflammatory synovial effusions obtained from patients with knee arthritis not induced by crystals. For each SF, DQ stained slides were analyzed by 2 experienced doctors in SF analysis. The observers were blinded to the type of crystal present in the SF. Each slide was analyzed by compensated polarized and transmitted light microscopy. SF was considered positive if intracellular and/or extracellular crystals were clearly identified. In addition, the observers were asked to identify the type of the crystals using compensated polarized light microscopy. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the DQ staining method were determined. 51 true positive and 28 true negative specimens were correctly classified (39 CPPD samples, 12 MSU samples, and 28 samples of crystals-unrelated arthropathies). All MSU specimens were correctly diagnosed.     

Comparison of two versus three smears in identifying culture-positive tuberculosis patients in a rural African setting with high HIV prevalence.

SETTING: Karonga district, northern Malawi. OBJECTIVE: To compare the sensitivity and specificity of two versus three smears for the diagnosis of pulmonary tuberculosis in a setting with high HIV prevalence. DESIGN: A total of 1992 pulmonary tuberculosis suspects with three sputum smears taken over a 2-7 day period and at least one culture result were studied. Smears were auramine stained and examined using fluorescence microscopy, and positives were confirmed with Ziehl-Neelsen staining and light microscopy. Cultures were set up on L?wenstein-Jensen media. True negative and positive status was defined on the basis of culture. The sensitivity, specificity, and positive and negative predictive values of two and three smears were compared. RESULTS: Compared to culture, the sensitivity, specificity, and positive and negative predictive values of three smears were 70%, 98%, 92%, and 92%, respectively. Restriction to the first two smears gave similar results. Of those detected as smear-positive using three smears, at least 97% would have been detected by two. Among those with HIV serology results available, the sensitivity of two smears for detecting culture-positive tuberculosis was identical to that using three. CONCLUSION: In this setting, using fluorescence and light microscopy, collecting two smears rather than three would only marginally reduce sensitivity and would slightly improve the specificity of diagnosis of tuberculosis; this is unaffected by HIV status. The potential for improving specificity is important because of the costs of misdiagnosis. In practice, both sensitivity and specificity may be increased due to the time saved by examining two rather than three smears.