AB1329 THE PRELIMINARY VALIDATION OF LASER DOPPLER FLOWMETRY IN SYSTEMIC SCLEROSIS ACCORDING TO THE OMERACT FILTER: A SYSTEMATIC REVIEW
Authors: Karin Melsens, Sarah Van Impe, Carmen Pizzorni, Maurizio Cutolo, Vanessa Smith
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Systemic sclerosis (SSc) is characterised by a widespread vasculopathy. The vasculopathy comprises the skin microcirculation and results in features such as Raynaud's phenomenon (RP) and digital trofic lesions. The quantification of the skin blood perfusion at the level of the finger (FBP) is a major need in the assessment of SSc in clinical and research setting<sup>1</sup>. Up to now, laser doppler flowmetry (LDF) has been the most thoroughly investigated instrument to assess the FBP in SSc. <h3>Objectives</h3> To investigate the validation status of LDF in SSc according to the 'Outcome Measures in Rheumatologic Clinical Trials' (OMERACT) filter. <h3>Methods</h3> Literature was systematically reviewed to detect all reports in which the assessment of the FBP in SSc patients was described. The OMERACT filter, including the domains of truth, discrimination and feasibility was applied and a quality assessment was done by the Good Methods Checklist<sup>2</sup>. Comparison between studies was eased by grouping the results per dynamic test situation (basal circumstances, cold/heat challenge and occlusion). <h3>Results</h3> The systematic search resulted in 4340 hits. After title and abstract screening 228 hits remained and of these, 79 full texts described the assessment by LDF. Fifty studies were included for quality assessment of which 17 studies were retained for conclusion making (fig 1). An overview of the validation status of LDF is given in table 1. Expert consensus is lacking on the face and content validity of LDF in SSc. The construct validity of LDF is partially validated (e.g. the correlation with laser speckle contrast imaging was attested in one study). Conflicting results exist on the discriminant capacity of LDF to distinguish healthy from diseased, primary from secondary RP and to differentiate between disease subsets. The addition of a heat challenge, as well as the evaluation of the post-occlusive hyperemic response to the LDF-measurement has the potential to elicit a difference between healthy and diseased. Lastly, there are no data on the feasibility of LDF in SSc. <h3>Conclusion</h3> This systematic review emphasizes the very preliminary validation status of LDF in the assessment of the FBP in SSc. No single application method has emerged as fully validated according to the OMERACT filter. <h3>References</h3> [1] Herrick A, et al. ARD 1998; 57:70-78 [2] Boers M, et al. The OMERACT handbook. Ottowa, ON, Canada: OMERACT; 2017 Only those studies which were found of good quality according to the Good Methods Checklist were considered and only the results where p-values were given were considered in this table. OMERACT= Outcome Measures in Rheumatologic Clinical Trails; HC= healthy controls; PRP= primary Raynaud's phenomenon; SRP= secondary Raynaud's phenomenon due to systemic sclerosis; LcSSc: limited cutaneous disease; DcSSc: diffuse cutaneous disease; PORH= post-occlusive reactive hyperaemia; NA= not applicable; ND= no data; V= valid if agreement exists among studies; PV= partially valid if disagreement exists among studies; UV= unvalid if agreement about insignificant results exists. <h3>Disclosure of Interests</h3> None declared