Establish The Detection Method Of Autoantibodies To Cell Membrane Associated DNA And Research The Value Of Clinical Application Of These Autoantibodies In Systemic Lupus Erythematosus

【Background】Systemic lupus erythematosus (SLE) is a systemic disease characterized bydiverse clinical subsets and a plethora of autoimmune features. The main pathogenesisis immune system disorders caused by T-lymphocyte abnormalities and B-lymphocyteover-activation. Many antibodies can be found in the serum of patients which candamage tissues and organs. Anti-Sm, anti-distrand-DNA antibody (anti-dsDNA) andanti-nucleosome antibody(AnuA) are the SLE relative specific antibodies. Thespecificity of these antibodies is higher, but the sensitivity is relatively low.Antinuclear antibody(ANA) have good sensitivity but relatively low specificity.Recent reports in the literatures say a kind of new autoantibodies associated with SLEcalled autoantibodies to cell membrane associated DNA(anti-cmDNA antibody).These autoantibodies have good sensitivity and specificity in the diagnosis of SLE.We came to the similar conclusions in our preliminary research. The aim of this studywas to do a further research about the value of anti-cmDNA antibody in the diagnosisof SLE and to compare the significance of anti-cmDNA antibody in SLE detectedwith indirect immunofluorescence(IIF) on human′s B lymphoma cell line Raji andpromyelocytic line HL60.【Objective】1. Compare the significance of anti-cmDNA antibody in SLE detected with IIF onhuman′s B lymphoma cell line Raji and promyelocytic line HL60.2. Explore the diagnostic value of anti-cmDNA antibody in SLE.3.Research on the correlation between anti-cmDNA antibody and clinicalcharacteristics, laboratory parameters, SLEDAI score in SLE.【Methods】We included 306 patients with SLE. As control groups, we included 192 patientswith other rheumatic diseases and 50 healthy controls. Record their demographicdatum and 178 SLE patient's clinical characteristics, laboratory parameters andSLEDAI score in detail. Establish the indirect IIF to detect the anti-cmDNA antibody:a. Culture cell line Raji and HL60; b. Detect the anti-cmDNA antibody withIIF; c. Judgment the results of fluorescence. Calculate respectively the sensitivity andspecificity of anti-cmDNA antibody in SLE detected with IIF on cell line Raji andHL60. Compare the significance of anti-cmDNA antibody in SLE detected with IIFon cell line Raji and HL60. Explore the diagnostic value of anti-cmDNA antibody inSLE. ANA and anti-dsDNA were measured by IIF. Anti-Sm were measured byimmuno-double diffusion and western blotting. AnuA were measured by enzymelinked immunosorbent assay.【ResultResults】1. Cell line Raji was more likely to recovery and the fluorescence graphics brightnesswas stronger than cell line HL60.2.There was no statistically significant difference in the sensitivity and specificity ofanti-cmDNA antibody in SLE detected with IIF on cell line Raji and HL60(P＞0.05).There was also no statistically significant difference in the positive predictive valueand negative predictive value(P＞0.05).3.The sensitivity of anti-cmDNA antibody detected with IIF on cell line Raji washigher than anti-dsDNA and anti-Sm(P＜0.01), the specificity of anti-cmDNA wasclose to anti-dsDNA(P＞0.05)and was lower than anti-Sm(P＜0.01). The sensitivityof anti-cmDNA was similar to AnuA(P＞0.05)and the specificity was lower thanAnuA(P＜0.01). The sensitivity of ANA was higher than anti-cmDNA(P＜0.01)and the specificity was much lower than anti-cmDNA(P＜0.01).4.The sensitivities of anti-dsDNA, anti-Sm and AnuA were much higher whencombined detected with anti-dsDNA than detected respectively(P＜0.05).5.The prevalence of hematuria, proteinuria, skin rash, alopecia, febricity, CRPelevated, leukopenia, thrombocytopenia and hypocomplementemia was notstatistically higher compared to the patients lacking anti-cmDNA(P＞0.05).We foundthat SLE patients with positive anti-cmDNA had relatively higher incidences ofmucosa ulcer(P＜0.05).The ESR of SLE patients with positive anti-cmDNA washigher than that of patients lacking anti-cmDNA(P＜0.05). Anti-cmDNA had nocorrelation with SLEDAI(P＞0.05).【Conclusions】1. Anti-cmDNA detected with IIF on cell line Raji was better than that detected withIIF on cell line HL60.2. We concluded that anti-cmDNA had higher sensitivity and specificity in SLE. Combined detection of anti-cmDNA and other autoantibodies might further improvethe sensitivity in SLE.3. Anti-cmDNA had correlation with mucosa ulcer and ESR. There was no correlationbetween anti-cmDNA and SLEDAI.