抗神经元抗体的检测及其在狼疮中枢神经系统病变中的临床应用研究

目的　建立检测抗神经元抗体 (anti neuronalantibodies,anti N)的细胞 ELISA方法 ,并评价其对系统性红斑狼疮中枢神经系统病变 (CNS SLE)的诊断价值。方法　以 1%多聚甲醛固定的SK N MC成神经瘤细胞株为抗原 ,采用细胞 ELISA方法 ,检测 12 3份血清 (包括CNS SLE 2 8例 ,无中枢神经系统受累的SLE 2 2例 ,其他结缔组织病 36例 ,正常血清 37例 )和 138份脑脊液 (包括CNS SLE 38例 ,无中枢神经系统受累的SLE 2 9例 ,其他结缔组织病 12例 ,有神经精神症状的其他疾病 5 9例 )中anti N。结果　血清中anti N在SLE中阳性率为 6 2 0 % (31/ 5 0 ) ,特异性为 91 8% ;脑脊液中anti N在CNS SLE中阳性率为 47 4% (18/ 38) ,特异性为 89 7% ,而无中枢神经系统受累的SLE (non CNS SLE)阳性率仅为 10 3 % (3/ 2 9) ,且抗体水平低于前者 ,二者在抗体水平和阳性率上差异存在显著性 (P均 <0 0 0 1) ;以意识障碍 /精神症状为主要表现的CNS SLE脑脊液中该抗体阳性率最高 ,分别为 75 0 %和 72 7% ,显著高于其他类型CNS SLE (P =0 0 1) ;8例CNS SLE患者治疗前后脑脊液中anti N水平分别为 0 47± 0 2 2和 0 2 2± 0 0 6 ,二者之间差异有显著性 (P <0 0 5 )。结论　血清中anti N对诊断SLE特异性较高 ;脑脊液中anti N是     

鞘内联合注射甲氨蝶呤加地塞米松治疗狼疮中枢受累

目的　探讨鞘内联合注射甲氨蝶呤加地塞米松在治疗系统性红斑狼疮 (SLE)中枢神经系统 (CNS)病变中的作用。方法　对 2 4例常规剂量糖皮质激素治疗无效的CNS、SLE患者予鞘内联合注射甲氨蝶呤加地塞米松各 10～ 2 0mg ,对其临床疗效及副作用进行观察 ,并对鞘内注射治疗前后CNS、SLE住院死亡率进行比较。结果　 2 2例CNS、SLE临床症状体征缓解 ,有效率 91 7% ;鞘内注射前脑脊液压力、蛋白及白细胞分别为 (2 0 2± 15 5 )mmH2 O、(145 2± 876 )mg/L及 (2 5 1± 14 3)× 10 6/L ,而鞘内注射后分别下降为 (12 9± 10 8)mmH2 O、(6 0 8± 383)mg/L及 (6 8± 2 1)× 10 6/L ,P均 <0 0 5 ;4例出现一过性不良反应 ,如双下肢烧灼感、头痛及一过性大小便失禁 ;鞘内注射前后CNS、SLE住院死亡率分别为 30 2 (2 9/ 96例 )及 4 0 % (3/ 75例 ) ,P <0 0 1。结论　鞘内联合注射甲氨蝶呤加地塞米松是治疗CNS、SLE的一种有效方法 ,值得进一步临床研究。     

系统性红斑狼疮患者血清5种抗细胞核及细胞浆抗体检测及其意义

采用间接免疫荧光法检测60例系统性红斑狼疮(SLE)、30例其他结缔组织病及30例正常对照者血清中的抗核抗体(ANA)水平,用酶联免疫印记法检测抗Sm抗体、抗dsDNA抗体、抗核小体抗体(AnuA)、抗组蛋白抗体(AHA)和抗核糖体P蛋白抗体(APPA).发现SLE组抗Sm抗体、抗dsDNA抗体、AnuA、AHA及APPA的阳性率明显高于病例对照组及正常对照组;SLE组ANA的阳性率为98%,且滴度83.5%≥1:320,更有38.3%≥1:10 000.认为联合检测多种抗体可以避免因单项检测出现的漏诊,提高了对SLE诊断的敏感性和诊断效率.     

sFas与sFasL在自身免疫疾病中的意义

目的　研究sFas与sFasL在系统性红斑狼疮 (SLE)等自身免疫疾病中的意义及抗单链DNA(ssDNA)抗体与sFas和sFasL介导凋亡的相关性。方法　采用夹心ELISA方法检测 31例SLE病人 ,32例类风湿关节炎 (RA)病人 ,2 0例 1型糖尿病 (IDDM )病人及 5例多发性硬化病 (MS)病人血清中sFas与sFasL含量及抗ssDNA抗体水平。结果　在SLE、RA、IDDM及MS患者血清中的sFas含量 (pg/ml)分别为 2 881± 16 5 3 ,988± 6 96 ,135 2± 413 ,15 40± 5 6 6 ,明显高于正常对照 (P <0 0 0 2 ) ,SLE病人sFas含量高于RA ,MS ,IDDM病人。SLE、RA患者血清sFasL含量 (pg/ml)分别为5 35± 431、12 38± 1184,明显高于正常对照 (P <0 0 2 ) ,MS、IDDM患者血清sFasL含量 (pg/ml)分别为 2 5 1± 140 ,2 11± 73 ,低于正常对照 (P >0 0 5 )。在SLE、RA病人中 ,高浓度sFasL者伴有高浓度sFas。在SLE病人中 ,所有抗ssDNA抗体阳性者均伴有高浓度sFas,所有抗sFas阴性者 ,ssDNA抗体也为阴性。结论　在SLE等疾病中sFas水平明显高于正常人 ,可作为疾病进展与治疗效果的判断指标。抗ssDNA抗体与sFas具有关联性。sFas与sFasL在疾病中的相互作用及动态变化有待进一步研究     

系统性红斑狼疮患者抗核糖体P0蛋白抗体的临床意义

目的 探讨系统性红斑狼疮(SLE)患者抗核糖体P0蛋白抗体的临床意义.方法 采用线性免疫分析法和免疫印迹法检测49例SLE患者及61例其他结缔组织病患者血清抗P0抗体和抗核糖体抗体(rRNP),分析抗P0抗体与rRNP抗体在SLE和其他结缔组织病中阳性率的差异及抗P0抗体与SLE临床表现和其他自身抗体的关系.结果 SLE患者中抗P0抗体的阳性率为36.7%,rRNP抗体的阳性率为6.1%,二者之间差异有统计学意义(P＜0.01);抗P0抗体在其他结缔组织病中均为阴性.在SLE患者中,抗P0抗体阳性组皮疹的发生率为77.8%,阴性组为35.5%(P＜0.05);抗SmD1抗体的阳性率在抗P0抗体阳性组中为61.1%,在阴性组中为19.4%(P＜0.01).抗P0抗体对诊断SLE的敏感性为36.73%,特异性为100%,阳性预测值为100%,阴性预测值为66.30%.结论 抗P0抗体对诊断SLE的特异性强,阳性预测值高.抗P0抗体与SLE皮疹和抗SmDl抗体阳性相关.     

系统性红斑狼疮患者CD5+B细胞的测定和意义

目的探讨外周血中CD5 B细胞在系统性红斑狼疮(SLE)活动中的作用及相关性。方法利用流式细胞分析法对57例SLE患者和35名正常人群外周血CD5~ B细胞进行检测,并且同时检测抗dsDNA抗体、抗核抗体(ANA)、抗心磷脂抗体(ACL)、补体C3、C4。结果SLE患者CD5~ B细胞水平[(2．1 0．4)%]与正常人[(1．5±0．4)％]比较差异有统计学意义(P＜0．05),活动期SLE患者CD5~ B细胞水平(2．5±0．5)％显著高于稳定期(1．4±0．5)％；CD5 B细胞与dsDNA、ANA、抗心磷脂抗体(ACL)升高呈正相关,与补体c3呈负相关。结论系统性红斑狼疮患者外周血CD5~ B细胞明显升高,与SLE疾病活动有一定关系。     

抗核小体抗体测定在系统性红斑狼疮诊断中的意义

目的　评价抗核小体抗体 (AnuA)对系统性红斑狼疮 (SLE)诊断的敏感性和特异性 ,并了解其与SLE活动性的关系及与其他自身抗体的关系。方法　用酶联免疫吸附 (ELISA)测定方法检测SLE患者、疾病对照组 (包括原发性干燥综合征、多发性肌炎、皮肌炎、系统性硬化症 )和正常对照组血清中的AnuA ,并记录SLE患者的各种临床表现及实验室指标 ,分析其与AnuA的关系。结果　 10 3例SLE患者中 6 9 9%血清AnuA阳性 ,6 6例疾病对照组仅 3 0 %阳性 ,30名正常对照组全部阴性 ;SLE组患者AnuA阳性率显著高于疾病对照组和正常对照组 (P <0 0 1) ,AnuA在SLE中检测的敏感性和特异性分别为 6 9 9%和 97 9%。AnuA阳性组的SLE患者肾损害、皮肤损害的发生率(6 1 1%、70 8% )明显高于AnuA阴性组 (2 9 0 %、32 3% ) (P <0 0 5 ) ;AnuA阳性组与AnuA阴性组相比 ,在年龄、性别、病程上差异无显著性 (P >0 0 5 )。AnuA滴度的高低与SLE患者的SLEDAI评分有明显相关性 (r=0 2 82 ,P <0 0 5 )。抗dsDNA抗体、抗Sm抗体、快速狼疮因子 (DNP)、抗组蛋白抗体 (AHA)阴性的SLE患者AnuA的阳性率分别为 6 5 6 %、6 8 0 %、6 3 9%、6 4 1%。结论　AnuA对SLE诊断的敏感性高、特异性强 ;它与SLE疾病活动性密切相关 ,对抗dsDNA抗体、Sm、DNP及AHA     

抗dsDNA抗体两种检测方法的比较

比较抗双链DNA(dsDNA)抗体的两种检测方法。用胶体金快速斑点渗滤技术(DIGFA)及马疫锥虫间接荧光抗体染色法检测27名正常儿童和46例系统性红斑狼疮(SLE)病人和非狼疮病人血清抗dsDNA抗体,27名正常儿童和17例非狼疮病人血清抗dsDNA抗体经两种方法检测均为阴性;29例SLE患者用两种方法检测出抗dsDNA抗体的阳性符合率为94.44％(17/18)。说明两种方法具有一致的特异性和敏感性,DTGFA更简捷、快速、方便。     

抗核小体抗体诊断系统性红斑狼疮的价值

280份血清,取自健康体检者50例,类风湿关节炎（RA）74例,系统性红斑狼疮（SLE）106例．其他结缔组织病50例．分别检测其抗核抗体（ANA）,抗双链DNA（dsDNA）,抗史密斯（Sm）,抗组蛋白（His）及抗核小体抗体（AnuA）抗体。结果5种抗体诊断SLE的敏感性和特异性为;ANA96．2%、31％,AnuA80．1％、93％,dsDNA56．6%、92％,Sm49．7％、90％,His54．7％、85%。ANA、AnuA敏感性明显高于其他3种抗体（P〈0．001）．AnuA、dsDNA、HiS、Sm的特异性明显高于ANA（P〈0．001）。AnuA是SLE的又一种特异性抗体,其与ANA、dsDNA抗体及Sm抗体、His抗体联合检测对SLE的诊断有重要意义。     

探讨狼疮带试验对系统性红斑狼疮的临床诊断意义

目的　明确狼疮带试验 (LBT)在系统性红斑狼疮 (SLE)诊断中的作用及LBT与狼疮性肾损害的关系。方法　回顾分析 2 0 0例LBT活检结果。结果　LBT在SLE患者中敏感性、特异性分别为 71%和 82 %。LBT阳性预测值和阴性预测值分别为 91%和 5 0 %。LBT与抗核抗体(ANA) ,抗dsDNA抗体对SLE诊断的敏感性相近 (P >0 0 5 )。SLE伴肾损害组LBT阳性率为 86 % ,显著高于SLE不伴肾损害组 (37% ) (P <0 0 5 )。 2 8例肾活检中 ,LBT阳性组弥漫性增生型狼疮肾炎的发生率为 6 9% ,显著高于LBT阴性组 (17% ) (P <0 0 5 )。LBT免疫成分分析发现IgG及C1q阳性与肾损害密切相关。结论　LBT是SLE辅助诊断的敏感和特异的指标 ,而其较高的阳性预测值提示其在SLE疑难病例诊断中有重要价值。LBT与SLE肾损害的发生密切相关。     

Cell-ELISA detection of antineuronal antibodies in central nervous system involvement in systemic lupus erythematosus

OBJECTIVE: To develop a cell-ELISA method to detect antineuronal antibodies (anti-Ns) and evaluate the diagnostic value of anti-Ns in central nervous system involvement in systemic lupus erythematosus (CNS-SLE). METHOD: Anti-N was assessed in both serum and cerebrospinal fluid (CSF) samples from 38 patients with CNS-SLE, 29 with SLE without CNS involvement (non-CNS-SLE), 36 with other rheumatic diseases and 59 with non-rheumatic diseases with the CNS manifestations using a cell-ELISA method with 1% paraformaldehyde-fixed SK-N-MC neuroblastoma cells as substrate. Serum samples from 37 healthy donors were also included in this study. Patients with CNS-SLE who were anti-N positive in CSF were studied serially for CSF anti-N levels at times of treatment-associated improvement in CNS symptoms. RESULTS: Serum anti-N levels were significantly increased in patients with SLE compared with other groups, with a sensitivity of 61.2% (41/67) and a specificity of 91.8% (p<0.001). CSF anti-N levels were significantly increased in patients with CNS-SLE, with a sensitivity of 47.4% (18/38) and a specificity of 89.7%, whereas only 10.3% (3/29) of patients with non-CNS-SLE had increased anti-N in CSF (p<0.001). CSF anti-N levels decreased significantly after effective treatment of CNS-SLE (p<0.05). CONCLUSION: Serum anti-N is relatively specific to SLE. CSF anti-N is a sensitive and relatively specific antibody in diagnosing CNS-SLE and correlates with CNS-SLE activity.     

Flow cytometric assessment of anti-neuronal antibodies in central nervous system involvement of systemic lupus erythematosus and other autoimmune diseases

The objective of this study is to evaluate the association between anti-neuronal antibody (anti-NA) and central nervous system (CNS) manifestations of systemic lupus erythematosus (SLE) and other rheumatic diseases using a flow cytometric method. Anti-NA was measured by flow cytometry in serum and cerebrospinal fluid (CSF) samples from patients with SLE (n=44 for serum, n=17 for CSF), other rheumatic diseases (n=64 for serum, n=21 for CSF) and from healthy controls (n=65 for serum, n=18 for CSF). Serum anti-NA was more frequently observed in SLE (31.8%, 14/44) than in other rheumatic diseases (4.7%, 3/64, P<0.001) or in healthy controls (0%, 0/65, P<0.00001). In SLE patients, the frequency of serum anti-NA was significantly higher in CNS-SLE (76.5%, 13/17) than in non CNS-SLE (3.7%, 1/27, P<0.000001). CSF anti-NA was detected in 88.2% (15/17) of CNS-SLE and was more frequently detected in CNS-SLE (15/17, 88.2%) than in other rheumatic diseases with CNS involvement (1/21, 4.8%, P<0.000001) or in healthy controls (0/18, P<0.000001). In conclusion, serum anti-NA was more frequently found in CNS-SLE than in non CNS-SLE, other rheumatic diseases or in healthy controls. The frequency of CSF anti-NA in CNS-SLE was significantly higher than in other rheumatic diseases with CNS involvement or in healthy controls.     

Evidence of autoantibodies to cell membrane associated DNA (cultured lymphocytes): a new specific marker for rapid identification of systemic lupus erythematosus

OBJECTIVE—Autoantibodies to cell membrane associated DNA are described in systemic lupus erythematosus (SLE). The specificity of these antibodies differ from antibodies to nuclear DNA.
METHODS—Using indirect immunofluorescence, a specific IgG was detected giving a characteristic pattern of continuous peripheral membrane fluorescence on cultured B-lymphocytes.
RESULTS—This pattern was observed in 53 of 80 serum samples of SLE patients but absent in the serum samples of the control populations: 15 rheumatoid arthritis, 38 ankylosing spondylarthritis, 17 non-inflammatory osteopenic patients, and 224 blood donors. In 34 Sjögren syndrome's patients one only showed a positive test. The cmDNA specificity of these antibodies was confirmed by pattern extinction with DNAse but not RNase or protease pre-treatment of the cells. IgG to cmDNA, separated by absorption/elution from purified cmDNA immobilised on DEAE-nitrocellulose reproduced the immunofluorescence pattern pictures. Extensive serum depletion of anti-double strand or single strand DNA antibodies by absorption to cellulose bound ds- or ss-DNA affected marginally the pericellular fluorescence revealing some minor cross reactivity with nuclear DNA. Moreover, in SLE patients without detectable antibody to ds-DNA, pericellular fluorescence could be visible.
CONCLUSION—This novel rapid immunofluorescence method may serve as an identification test of SLE patients. Given its positive (97.1%) and negative (92.9%) predictive value, sensitivity (66%) and specificity (99.5%), it improves on other diagnostic tests such as the detection of antibodies to Sm.

Keywords: anti-nuclear antibodies; systemic lupus erythematosus, immunofluorescence, cytoplasmic membrane associated DNA     

Cerebrospinal fluid IgM, IgA, and IgG indexes in systemic lupus erythematosus. Their use as estimates of central nervous system disease activity

Paired serum and cerebrospinal fluid (CSF) specimens from 13 patients with systemic lupus erythematosus (SLE) and central nervous system involvement (CNS-SLE) were studied for CSF IgM, IgA, and IgG indexes (indicators of intrathecal immunoglobulin synthesis) and CSF-serum albumin quotient (Q albumin) (an indicator of blood-brain-barrier function). We also studied 20 patients with noninflammatory neurologic diseases and seven patients with SLE without CNS involvement for comparison. In addition to an increase in the CSF IgG index, IgM and IgA indexes also were elevated in patients with CNS-SLE. All three indexes decreased significantly when CNS manifestations subsided by successful treatment. The Q albumin was normal in most patients. The elevation of CSF immunoglobulin indexes may be a result of polyclonal B-lymphocyte activation within the CNS, rather than the leak of immunoglobulins from the systemic circulation into the CNS. Since these indexes reflect CNS disease activity in SLE, they may be a successful tool for the management of SLE.     

Anti-Sm and anti-DNA antibodies in paired serum and synovial fluid samples from patients with SLE

Summary Antibodies to nuclear antigens (ANAs) are frequently found in the serum of patients with connective tissue diseases (CTDs). Particularly systemic lupus erythematosus (SLE), and have been implicated in the immune-complex mediated pathogenesis of these diseases. In this study we have compared the occurrence of precipitating ANAs in paired samples of serum and synovial fluid from patients with different CTDs. Of the 30 patients examined 3 had precipitating ANAs in their serum only, 1 in the synovial fluid only, and 3 had antibodies in both serum and synovial fluid. Precipitating ANAs in synovial fluid were found in 3/6 patients with SLE, 1 patient with RA/Sjogren's syndrome overlap, and one patient with RA/SLE overlap. Of the other 15 patients with RA, 2 had precipitating antibodies only in their serum. Two of the SLE patients had anti-Sm antibody, one in serum only and the other in both serum and synovial fluid. Detection by ELISA of class specific anti-Sm antibodies in serum or synovial fluid paralleled the occurrence of antidenatured DNA antibodies when both specificities occurred together. One SLE patient did show evidence in synovial fluids of elevated concentrations of specific antibody classes to individual antigens; however, elevated levels were more frequently found in serum. Local production of ANAs does not, therefore, appear to be a feature of synovial fluids from SLE patients.     

Anti-dsDNA antibody assay: high specificity and sensitivity with a filtration radioassay in comparison to low specificity with the standard ELISA

OBJECTIVE: To evaluate whether a new fluid-phase filtration radioassay possesses both high sensitivity and specificity compared with the currently used ELISA and Farr assays. METHODS: Sequential sera (25 samples) from 9 patients with systemic lupus erythematosus (SLE), sera from 20 patients with SLE possessing anti-dsDNA antibodies by the Crithidia assay, 75 patients with rheumatoid arthritis possessing rheumatoid factors, 50 healthy control subjects, 767 from patients with type 1 diabetes, and a commercial standard serum sample were tested for anti-dsDNA antibodies with the 3 different assays. RESULTS: Of serial dilutions of a standard anti-dsDNA antibody sample, only the highest positive sample (50 IU/ml) in the ELISA and the highest 2 positive samples (50 and 25 IU/ml) in the Farr assay were above the normal range. In contrast, all dilutions (to 2.5 IU/ml) of the standard anti-dsDNA antibody sample were above the normal range in the filtration radioassay. Using the values of 50 healthy control subjects in each assay to define the normal range, all 25 sequential sera from 9 patients with SLE were positive. In addition, 20/20 of the SLE individual sera, 2/75 (2.7%) of the RA sera, and 12/767 (1.6%) of the diabetes sera were positive (signal above normal range) in the filtration radioassay. The SLE sera were further examined in 2 additional assays, ELISA and Farr assay, and both assays were less sensitive and specific compared with the filtration radioassay. CONCLUSION: The fluid-phase filtration radioassay demonstrated high sensitivity and specificity for the detection of anti-dsDNA antibodies in SLE, with the standard ELISA exhibiting lower specificity. We suggest that testing for anti-dsDNA antibodies can be improved using a fluid-phase filtration radioassay in comparison to commercial assays.     

Anti-ribosomal P protein antibodies detected by immunoblotting in patients with connective tissue diseases: their specificity for SLE and association with IgG anticardiolipin antibodies

OBJECTIVE: To assess the prevalence and clinical and serological associations of anti-ribosomal P protein antibodies (anti-P antibodies) in patients with connective tissue diseases (CTDs) and investigate the immunobiological nature of autoantibody clustering in which anti-P antibodies play a part. METHODS: IgG anti-P antibodies in the sera of 267 patients with CTDs and 31 healthy subjects were analysed by immunoblotting performed on cytoplasmic extract of Raji cells. 60 patients with systemic lupus erythematosus (SLE), 32 systemic sclerosis, 46 primary Sj?gren's syndrome, 16 poly/dermatomyositis, 11 rheumatoid arthritis, 8 undifferentiated CTD, 72 overlap CTD, and 22 primary antiphospholipid syndrome were studied. Anti-P antibodies were affinity purified by elution from nitrocellulose bound antigen and tested by ELISA for their binding activity to cardiolipin. RESULTS: Anti-P antibodies were detected in 16 (6%) patients and in none of the controls: 12/60 SLE (20%) and 4/80 undifferentiated/overlap patients with CTD (5%). A close association of IgG antibodies with P proteins and with cardiolipin was seen in lupus sera (p=0.0009, odds ratio 18.33). Anti-P antibodies from 9 of 12 anti-P lupus serum samples could be affinity purified and none of the affinity purified fractions cross reacted with ELISA plate coated cardiolipin. CONCLUSIONS: Anti-P immunoreactivity is a specific marker of SLE and lupus-like disease and its detection is recommended as a powerful diagnostic tool. Anti-P antibodies are strongly clustered with IgG anticardiolipin antibodies in lupus sera, even if they are independently elicited. This suggests that their cognate autoantigens play a part in a common pathogenetic pathway in SLE.     

Enzyme immunoassay for antibodies to native DNA. Specificity and quality of antibodies

An enzyme immunoassay was developed to detect antibodies to native DNA; DNA coating conditions that maximized sensitivity, specificity, and reproducibility were selected. Sera of patients with systemic lupus erythematosus (SLE) were positive more frequently by this immunoassay than by the Crithidia luciliae assay or by counterimmunoelectrophoresis. By enzyme immunoassay, 94% of sera with active SLE and 70% of sera from patients with inactive SLE were positive, as were 16% from those suspected of having SLE, and 2.5% of normal persons. Specificity for native DNA was shown for both SLE and normal sera by inhibition studies and by S1 nuclease treatment of polystyrene-bound native DNA. The enzyme immunoassay correlated more with serum hemolytic complement levels that did the other 2 assays, suggesting that it detects biologically more relevant anti-DNA antibodies than do the other 2 tests.     

抗细胞膜DNA抗体的测定及其在系统性红斑狼疮诊断中的意义

目的建立抗细胞膜DNA(mDNA)抗体测定的方法,研究其在系统性红斑狼疮(SLE)诊断中的敏感性和特异性,以及与SLE临床特点及免疫学异常的关系.方法检测SLE患者、疾病对照组和正常对照组血清中的抗mDNA抗体,并分析SLE患者的各种临床表现及实验室指标与抗mDNA抗体的关系.同时研究细胞膜DNA分子在不同细胞表面的表达,用DNA酶、RNA酶及胰酶鉴定抗原性质.结果抗mDNA抗体在SLE中检测敏感性73.3%(152/207),特异性96.4%,疾病对照组阳性率5.4%(9/167),82名正常对照组均为阴性,抗mDNA抗体阳性率在SLE组明显高于疾病对照组和正常对照组(P＜0.01).抗mDNA抗体在其他自身抗体阴性的SLE患者中有较高的检出率,在抗双链DNA(dsDNA)抗体、抗Sm抗体、快速狼疮因子(DNP)、抗组蛋白抗体(AHA)、抗核小体抗体(AnuA)阴性的SLE患者中抗mDNA抗体的阳性率分别是73.8%、62.7%、65.3%、57.8%和51.6%.该抗体阳性组SLE患者皮疹,脱发,关节痛,白细胞和C3、C4减低及IgG、IgA、IgM升高较为常见,但与SLE患者病情活动指数无关.本文还证实细胞膜DNA在人B细胞、T细胞上均有表达,以Raji细胞株表达较好.用DNA酶预处理的细胞涂片再行检测后膜荧光图形消失,而用RNA酶、胰酶预处理后并不消失,证实其为膜DNA抗原.结论抗mDNA抗体是一种诊断敏感性高、特异性强的SLE血清学指标之一,尤其对抗dsDNA、抗Sm、抗DNP、AHA、AnuA阴性的SLE的诊断有参考意义.     

Enzyme immunoassay for antibodies to native DNA

An enzyme immunoassay was developed to detect antibodies to native DNA; DNA coating conditions that maximized sensitivity, specificity, and reproducibility were selected. Sera of patients with systemic lupus erythematosus (SLE) were positive more frequently by this immunoassay than by the Crithidia luciliae assay or by counterimmunoelectrophoresis. By enzyme immunoassay, 94% of sera with active SLE and 70% of sera from patients with inactive SLE were positive, as were 16% from those suspected of having SLE, and 2.5% of normal persons. Specificity for native DNA was shown for both SLE and normal sera by inhibition studies and by S1 nuclease treatment of polystyrene-bound native DNA. The enzyme immunoassay correlated more with serum hemolytic complement levels than did the other 2 assays, suggesting that it detects biologically more relevant anti-DNA antibodies than do the other 2 tests.