Background RA is a chronic inflammatory rheumatic disease, and early diagnosis and treatment can improve prognosis¹.Surface-enhanced laser parsing ionization/time of flight mass spectrometry (SELDI-TOF-MS) combining a protein chip and mass spectrometry technology own the advantages of low dosage of samples, direct point sample detection and high sensitivity.

Objectives SELDI used to profile and compare the proteomes in serum samples of RA patients including complicated with Sjogren's syndrome (SS), interstitial lung disease (ILD). Using Biomarker Wizard software and Biomarker Pattern Software established diagnostic model, and calculate sensitivity and specificity,which can simplify clinical procedures, save medical costs and explore the pathogenesis.

Methods Using the Biomarker Wizard and Biomarker Pattern software to establish the diagnosis prediction model to predict RA disease progression between the following groups, including simple RA patients (n=44) and RA-SS patients (n=18), RA patients (n=44) and RA-ILD (n=22), RA patients (n=44) and RA-ONFH (n=6). Also 96 RA patients and 77 healthy control, which were randomly allocated to the training set (83 RA patients and 56 healthy controls) and test set (14 RA patients and 20 healthy controls)to develop and verify a pattern by means of decision treealgorithm.

Using the Biomarker Wizard and Biomarker Pattern software to establish the diagnosis prediction model to predict RA disease progression between the following groups, including simple RA patients (n=44) and RA-SS patients (n=18), RA patients (n=44) and RA-ILD (n=22). Also 96 RA patients and 77 healthy control, which were randomly allocated to the training set (83 RA patients and 56 healthy controls) and test set (14 RA patients and 20 healthy controls)to develop and verify a pattern by means of decision treealgorithm.

Results 1. Comparison of RA patients and healthy controls: there are 22 up-regulated expression in RA, 36 down-regulated. The diagnostic model of M/Z3448.857,4716.712,8214.285 and 10645. The sensitivity and specificity is 91.566% and 92.857%, the area under the ROC curve was 0.937, to verify the diagnosis model, we get a sensitivity of 100% and a specificity of 95%. 2. Comparison of the simple RA and RA -ILD. The diagnostic model of M/Z10645.1, M/Z12595.86. The sensitivity and specificity is 86.4% and 84.1% and the area under the ROC curve was 0.856.3. Comparison of the simple RA and RA -SS: The diagnostic model of M/Z6635.623, M/Z33897.72. The sensitivity and specificity is 77.8% and 79.5% and the area under the ROC curve was 0.794.

Conclusions The serum protein fingerprinting by SELDI-TOF-MS could identify new biomarkers in RA. The biomarkers may play an important role in pathogenesis of RA. We could diagnose RA in early stage, predict disease progression and determine disease activity by these biomarkers.

References

1. Vincent Goëb1, Marlène Thomas-L'Otellier2,et al. Candidate autoantigens identified by mass spectrometry in early rheumatoid arthritis are chaperones and citrullinated glycolytic enzymes. Arthritis Research & Therapy, 2009, 11:R38.

2. Jr GW, Cazares LH, Leung SM, Nasim S, Adam BL, Yip TT. Protein chip surface enhanced laser desorption/ionization (SELDI) mass spectrometry: a novel protein biochip technology for detection of prostate cancer biomarkers in complex protein mixtures. Prostate Cancer Prostate Dis.1992;2:264–76.

References

Disclosure of Interest None declared