Description of Peripheral Blood Perfusion by Laser Speckle Contrast Analysis (LASCA) in ‘Early’ versus ‘Clinically Overt’ Systemic Sclerosis in Routine Clinics

Abstract: Objective: To investigate in an unselected, systemic sclerosis (SSc) cohort if baseline laser speckle contrast analysis (LASCA) peripheral blood perfusion (PBP) measurements differ between ‘early’ SSc (without skin involvement, or ‘limited’ SSc—LSSc) and ‘clinically overt’ SSc (with skin involvement, limited cutaneous SSc—LcSSc and diffuse cutaneous SSc—DcSSc) in routine setting. Methods: A group of twenty consecutive ‘early’ SSc patients and forty consecutive ‘clinically overt’ SSc patients (twenty LcSSc and twenty DcSSc) underwent clinical and LASCA examinations (to assess the peripheral blood perfusion [PBP] of both hands volar). Results: No statistically significant difference in adjusted PBP was found in the ‘early’ versus the ‘clinically overt’ group (p = 0.77) when adjusted for possible confounding factors (e.g., vasoactive medication, active smoking, history of DTL and disease duration). A wide variability was noted when observing the individual datapoints of each subset. Conclusion: This study with an unselected SSc population in daily routine, non- research setting, showed there was no difference in adjusted PBP at baseline between ‘early’ SSc and ‘clinically overt’ SSc when corrected for possible confounding factors. Interestingly a wide variation of individual datapoints were observed in each subset, which emphasizes the heterogeneity of SSc.