POS0474 FACTORS ASSOCIATED WITH EROSIVE RHEUMATOID ARTHRITIS, A MULTIMARKER PRINCIPAL COMPONENT ANALYSIS (PCA) AND PRINCIPAL COMPONENT REGRESSION (PCR) ANALYSIS

Background Various clinical (disease activity, seropositive RA etc.) and metabolic risk factors (Dkk1 have been associated with erosive rheumatoid arthritis (RA). However, such might be intertwined, multicollinearity reduce our ability to discern the individual contribution score. Principal component analysis (PCA) is statistical technique for reducing dataset’s dimension principal regression (PCR) a based on PCA. PCR overcomes problem. Objectives To investigate bone using PCA PCR. Methods We conducted cross-sectional patients not responding first-level disease-modifying antirheumatic drug, candidate bDMARD treatment. Clinical, radiographic (both hands feet x-ray), laboratoristic densitometric (BMD parameters were collected. Sharp van der Heijde Score (SvdHS) was calculated by two independent readers. Serum samples collected assayed C-terminal telopeptide of type I collagen (CTX), Procollagen Intact N-Terminal Peptide (P1NP), Dkk1, Sclerostin (SOST), 25-OH-Vitamin D (VitD), PTH. applied dimensionality dataset find clusters variables recording largely redundant information. PCs selected eigenvalues explaining >75% total variance. used predict SvdHS. Results analyzed package GraphPad Prism version 9.5.0 Windows, Software, San Diego, California USA. 62 aged 57.2 years (SD 12.1) consecutively enrolled. Mean DAS28-CRP 4.17 1.27) median SvdHS 24 (IQR 12-53). The loadings plot ( Figure 1 ) shows correlated in (vectors). In Table are presented results as outcome. found that age, GC treatment, ACPA titer, RF CRP levels, ESR, CTX serum levels Dkk1 significantly positively SvdHS, whereas P1nP PGA negatively 1. Loadings from When vectors close, forming small angle, they represent correlated. If meet each other at 90°, likely diverge form large angle (close 180°), negative Variable Estimate Standard error P value Intercept -13,85 26,92 0,61 Age 0,54 0,18 0,006 Weight 0,004 0,13 0,97 daily dose 2,05 0,68 0,007 TJ -0,22 0,29 0,45 SJ -0,06 0,34 0,85 -2,08 0,84 0,02 PhGA -0,45 1,04 0,66 0,003 0,03 0,10 0,04 0,01 0,39 0,15 ESR 0,44 0,12 0,002 Hb -0,14 0,16 0,40 30,05 13,62 -0,20 0,08 0,32 0,14 SOST 0,28 0,52 OPG -0,39 0,72 0,59 RANKL -12,86 13,49 0,3514 PTH -0,2879 0,1694 0,1041 VitD 0,1291 0,1990 0,5235 BMD LS Ts 1,163 1,694 0,4999 Neck -0,8988 1,585 0,5766 Tot -0,7266 1,492 0,6314 Conclusion seropositivity, inflammation RA. independently disease less erosions. REFERENCES: NIL. Acknowledgements: Disclosure Interests Giovanni Adami Speakers bureau: EliLilly, Theramex, Amgen, UCB, Galapagos, Fresenius Kabi, Orsolini: None declared, Angelo Fassio: Ombretta Viapiana: Elena Sorio: Camilla Benini: Davide Gatti: Bertelle: Maurizio Rossini: declared.