Objectives The aim of this study was to asses PBP by new technique laser speckle contrast analysis (LASCA) in SSc patients with different patterns of nailfold microangiopathy, checking for any correlations between LASCA and laser Doppler flowmetry (LDF) techniques (1-3).
Methods Sixty-one SSc patients and 61 sex and age-matched healthy subjects were enrolled, after informed consent was signed. PBP was analysed by LASCA in both SSc patients and healthy subjects, by creating eight regions of interest (ROI) at the fingertips of the 2nd-5th finger bilaterally, after a 30 second recording of whole hand: the average perfusion was scored as perfusion units (PU). PBP was measured also by LDF at the central area of the fingertips, through a 30 second recording for each fingertip (2). Peripheral microangiopathy was detected and scored by nailfold videocapillaroscopy (NVC), assessing the proper pattern of microvascular damage (Early, Active, or Late), calculating the microangiopathy evolution score (MES) (4-6). Patients enrolled into the study were not taking vasoactive drugs. Non-parametric tests were used for the statistical analysis.
Results PBP was significantly lower in SSc patients than in healthy subjects, as evaluated by both LASCA (median 85 and 187 PU, respectively; p<0.0001) and LDF techniques (median 71 and 185 PU, respectively; p<0.0001). PBP was progressively lower in SSc patients with an “Early”, “Active” or “Late” NVC pattern, as evaluated by both LASCA (median 90, 84 and 78 PU, respectively; p=0.04) and LDF techniques (median 86, 75 and 63 PU, respectively; p=0.002). A negative correlation was found between MES and PBP values, as evaluated by both LASCA (p=0.006) and LDF (p=0.002) methods. A strong positive correlation was found between LASCA and LDF in the evaluation of PBP values, in healthy subjects and in SSc patients (p<0.0001). Intra-operator reproducibility was 95% for LASCA and 87% for LDF assessment.
Conclusions As evaluated by LASCA, PBP was found lower in SSc patients than in healthy subjects, and was found progressively lower in SSc patients with worsening pattern of nailfold microangiopathy. There was a significant positive correlation between LASCA and LDF in the assessment of PBP. However, LASCA is less time consuming than LDF and shows lower intra-operator variability.
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Disclosure of Interest: None Declared