ABSTRACT
Objective To analyze the efficacy of the combination of MALDI-TOF and immunoadsorption to detect new biomarkers for lupus. Methods Twenty lupus patients at active stage (SLE group), 10 SLE patients in remission (SLE control group), 10 RA patients and 10 PSS patients (other rheumatic disease control group) and 20 healthy volunteers (healthy control group) were enrolled. The serum samples before and after immunoadsorption from SLE group and those from the control groups were co-incubated with activated chitosan copper derivative nano material. The adsorbed nano material was spotted onto the matrix used in MALDI-TOF for analysis by the Axima-CFR plus MALDI-TOF mass spectrometer. T-test was used for statistical analysis. Results MALDI-TOF MS screening showed that three potential protein biomarkers of mass-to-charge (m/z) ratio 3136, 3264, 3326 were found to be very specific for lupus patients: All of them were expressed before immunoadsorption in high quantity and none of them could be detected both after immunoadsorption and in all the three control groups. None of them (<10 000) were in the molecular weight range of the biomarkers used nowadays such as auto antibodies and complement (>50 000). Conclusion The combination of MALDI-TOF and immunoadsorption is effective in the detection of new serum protein biomarkers for lupus and it may be helpful in the screening of SLE patients at active stage from healthy people.