Background:Up to 30% of Psoriasis (PsO) patients are prone to develop Psoriatic Arthritis (PsA). Agreement on how to identify PsO patients at risk of developing PsA is still lacking (1).Objectives:To identify predictors of PsA development in PsO patients through a systematic literature review (SLR) and meta-analyses (MA).Methods:MEDLINE, EMBASE and COCHRANE databases were searched (up to February 22nd, 2020). The PICO framework (population = PsO patients; intervention = clinical, environmental, imaging and genetic features; comparator = not applicable; outcome = PsA development) was used to design searches and define the eligibility of studies for inclusion. The MA focuses on 3 major features as possible predictors: i) PsO skin and nail involvement; ii) musculoskeletal (MSK) complaints; iii) inflammation and structural damage detected by imaging (Table 1). The sample estimates of the relative risk were pooled only when the studies were homogeneous in terms of cohort of patients, follow-up, study design and metrics.Results:4698 articles were screened for eligibility, 110 underwent a full reading and 29 were finally included. Figure 1 shows the study flow-chart for article selection. Though pooling was judge not appropriate, 5/7 prospective studies significantly support a predictive value of PsA development in patients with severe PsO (n=174635). While the predictive value of nail involvement is not well defined (n=2202), the pooled estimate from two cohort studies (n=474) supports nail pitting as predictor of PsA (RR=2.14 [1.32; 3.46]). Moving to the MSK complaints, the risk of developing PsA is about two times greater in PsO with than without arthralgia (pooled RR: 2.15 [1.16, 3.99]) within 2 years. Lastly, PsO patients with inflammation or structural damage detected by imaging are nearly four times more likely to develop PsA within 1-2 years (pooled RR from 4 cohort studies (n=247): 3.72 [2.12; 6.51]) (Table 1). The incidence rate of PsA varies from 1.34 to 5.9/100 p-ys in PsO and from 10.9 to 12.5/100 p-ys in PsOAr.Table 1.Studies reporting the major features as possible predictors of PsA development.PsO skin – severityPsO nail involvementPsO nail lesionsVariablesRelative Risk [95%CI]Follow-upWilson, 2009PsO nail involvementHRadjusted: 2.24 [1.26; 3.98]13.1±8.8 ysFaustini, 2015PASI score + PsO nail involvement/σ= -0.18[-0.84; 0.48] RR: 0.95 [0.37; 2.47]1.2±0.2 ysEder, 2016PASI score PsO nail involvement Type of PsO nail lesionsHR (>20vsHRunadjusted: 1.36 [0.76; 2.45] HRunadjusted: 2.21 [1.24; 3.92]4.1±2.1 ysEder, 2017PASI score + Type of PsO nail lesionsHRunadjusted: 1.05 [1.01; 1.09] HRunadjusted: 1.98 [0.83; 4.74]3.8±2.1 ysLewinson, 2017PsO severity defined from medicationsHRadjusted (moderate/severe vs mild): 5.02 [4.18; 6.04]5.1 ysEgeberg, 2018PsO severity defined from medicationsRR (severe vs mild): 1.31 [1.18; 1.46]18 ysElnady, 2019PASI score + PsO nail Involvement/σ= 0.79[-0.37; 1.95] RR: 1.43 [0.38; 5.31]2 ysGreen, 2020PsO severity defined from medicationRR (severe vs mild): 2.79 [2.49; 3.13]5.8 ysMSK-complaintsVariablesIncident-PsA casesFollow-upFaustini, 2015ArthralgiaRR: 1.98 [0.75; 5.19]1.2±0.2 ysEder, 2017ArthralgiaHRadjusted: 2.59 [1.15; 5.88]3.8±2.1 ysZabotti, 2019ArthralgiaRR: 4.44 [0.54; 36.72]1.6±0.5 ysSimon D, 2020ArthralgiaRR: 2.04 [0.86; 4.86]2.4±1.5 ysSub-clinical inflammation or structural damage detected by imagingVariablesIncident-PsA casesFollow-upFaustini, 2015MRIRR: 2.10 [0.75; 5.90]1.2±0.2 ysElnady, 2019MSK-USRR: 5.38 [1.17; 24.63]2 ysZabotti, 2019MSK-USRR: 6.86 [0.83; 56.63]1.6±0.5 ysSimon D, 2020HR-pQCTRR: 4.32 [1.96; 9.55]2.3±1.4 ysConclusion:Arthralgia and inflammation and/or structural damage detected by imaging are predictive features, likely prodromal, of PsA development. PsO severity and nail pitting are clinical manifestations related to PsA development.Figure 1.References:[1]Zabotti A, et al. Curr Rheumatol Rep. 2020 May 16;22(6):24. doi: 10.1007/s11926-020-00891-x.Disclosure of Interests:Alen Zabotti Speakers bureau: UCB, Novartis, Janssen, Paid instructor for: Amgen, Consultant of: Janssen, Orazio De Lucia Speakers bureau: Not relevant for this type of study, Consultant of: Not relevant for this type of study, Grant/research support from: Not relevant for this type of study, Garifallia Sakellariou Consultant of: AbbVie, Novartis, Alberto Batticciotto Speakers bureau: Not relevant for this type of study, Consultant of: Not relevant for this type of study, Grant/research support from: Not relevant for this type of study, Gilberto Cincinelli: None declared, Ivan Giovannini: None declared, Luca Idolazzi Speakers bureau: Eli Lilly, UCB, Celgene, MSD, Abbvie, Novartis, Paid instructor for: UCB, Gabriella Maioli Speakers bureau: Not relevant for this type of study, Consultant of: Not relevant for this type of study, Grant/research support from: Not relevant for this type of study, Ilaria Tinazzi Speakers bureau: Not relevant for this type of study, Consultant of: Not relevant for this type of study, Grant/research support from: Not relevant for this type of study, Daniel Aletaha Speakers bureau: not relevant for this type of study, Consultant of: not relevant for this type of study, Grant/research support from: not relevant for this type of study, Salvatore De Vita Consultant of: GSK, Roche, Grant/research support from: Not relevant for this type of study, Antonio Marchesoni Speakers bureau: not relevant for this type of study, Consultant of: not relevant for this type of study, Grant/research support from: not relevant for this type of study, Josef S. Smolen Speakers bureau: Not relevant for this type of study, Consultant of: Not relevant for this type of study, Grant/research support from: Not relevant for this type of study, Annamaria Iagnocco Speakers bureau: not relevant for this type of study, Paid instructor for: not relevant for this type of study, Consultant of: not relevant for this type of study, Grant/research support from: not relevant for this type of study, Dennis McGonagle Speakers bureau: ABBVIE, CELGENE, PFIZER, MSD, NOVARTIS, JANSSEN, UCB, GILEAD, BMS, LILLY, Grant/research support from: ABBVIE, CELGENE, PFIZER, MSD, NOVARTIS, JANSSEN, UCB, GILEAD, BMS, LILLY, Roberto Caporali Speakers bureau: Abbvie, Amgen, BMS, Celltrion, Galapagos, Gilead, Lilly, Pfizer, Roche, UCB, Sanofi, Fresenius Kabi, Samsung bioepis, MSD, Consultant of: Galapagos, Gilead, Lilly, Janssen, MSD