Indirect immunofluorescence on human B lymphoma cell line Raji and promyelocytic line HL60 for detection of DNA-associated autoantibodies to cell membrane in systemic lupus erythematosus

Objective To compare the significance of DNA-associated autoantibodies to cell membrane(cmDNA)in systemic lupus erythematosus(SLE)detected with indirect immunofluorescence on human B lymphoma cell line Raji and pmmyelocytic line HL60.Methods Indirect immunofluorescence assay both on cell line Raji and HL60 was used to measure anti-cmDNA antibodies in sera of 306 SLE patients.192 patients with other rheumatic diseases and 50 healthy controls.Results Indirect immunofluorescence assay on cell line Raji was used to measure anti-cmDNA antibodies.72.5% SLE and 10.4% other rheumatic diseases were positive for anti-cmDNA,but negative in 50 blood donors(P 0.05).The methods of culture,freeze and resuscitation on the two cells were similar.but cell line Raji was easier to resuscitate than cell line HL60.Observing with fluorescence microscope.we find that cmDNA was expressed on the both cells and the staining was stronger on cellline Raji than HL60.Conclusion Anti-cmDNA antibody has high positivity which is one of the most valuable marker in the diagnosis of SLE.We recommend to measure anti-cmDNA antibodies with indirect immunofluorescence assay on cell line Raji rather than HL60. Key words: Lupus erythematosus,systemic; Autoantibodies; Anti-cmDNA antibodies; Cell line Raji; Cell line HL60