Background Systemic sclerosis (SSc) is characterized by decreased peripheral blood perfusion (BP) and increased dermal thickness (DT) (1-3).

Objectives The aim of this study was to identify possible correlations between BP, evaluated by laser speckle contrast analysis (LASCA), and DT, evaluated by both high frequency skin ultrasound (US) and modified Rodnan skin score (mRSS), in three different body areas (periungual, dorsum of hand and zygoma) of SSc patients.

Methods Sixty-five SSc patients and 65 age and sex matched healthy subjects were enrolled. LASCA was performed at the level of both face and dorsal aspect of hands (4,5). Afterwards, different regions of interest (ROIs) were created to calculate BP at the level of third periungual areas, dorsum of both hands, and zygoma. Both US and mRSS were performed in the same three body areas in SSc patients (3,6). All patients were assessed by nailfold videocapillaroscopy (NVC) to classify and score the severity of microangiopathy (“Early”, “Active”, or “Late” pattern) (7,8). Statistical analysis was performed by non parametric tests.

Results In SSc patients, a statistically significant negative correlation was observed at the level of fingers between BP and both US-DT (r=-0.43, p=0.0005) and mRSS-DT (r=-0.42, p=0.0007). No statistically significant correlation was found between BP and both US-DT and mRSS-DT at the level of hand dorsum (p=0.61 and p=0.16, respectively) and zygoma (p=0.55 and p=0.35, respectively). In healthy subjects, no statistically significant correlation was detected between BP and DT (evaluated by US) at the three body levels. Furthermore, SSc patients showed a statistically significant lower BP at the level of both periungual area and hand dorsum than healthy subjects (p=0.0001), but no statistically significant difference of BP values was observed between SSc and healthy subjects at the level of zygoma (p=0.31). In addition, SSc patients showed a statistically significant higher DT at any level when compared with healthy subjects (p<0.0001, for all). In SSc patients, a significant positive correlation was observed between the two methods to evaluate DT (US and mRSS) (periungual p<0.0001; dorsum p=0.03; zygoma p=0.0001) at the level of the three areas. DT was found progressively higher, as well as BP was found progressively lower, in patients with “Early”, “Active” and “Late” pattern of microangiopathy.

Conclusions This study demonstrates a negative relationship between BP, evaluated by LASCA, and DT, evaluated by both US and mRSS, in SSc patients only at peripheral level. A significant positive correlation was observed between US and mRSS in the assessment of DT. BP was found progressively lower in SSc patients with worsening NVC patterns of microangiopathy, in contrast DT was progressively higher.

References

1. Cutolo M, et al. J Rheumatol 2010; 37:1174-80.

2. Rosato E, et al. Rheumatology 2011;50:1654-8.

3. Moore TL, et al. Rheumatology 2003; 42: 1559-63.

4. Sulli A, et al. Ann Rheum Dis 2014;73:2059-61.

5. Ruaro B, et al. Ann Rheum Dis 2014;73:1181-5.

6. Sulli A, et al. Ann Rheum Dis. 2014;73:247-51.

7. Sulli A, et al Arthritis Rheum. 2012; 64: 821-5.

8. Cutolo M, et al. J Rheumatol. 2000;27:155-60.

Disclosure of Interest None declared