Next to its early diagnostic role, in discerning a primary from a secondary Raynaud's phenomenon (RP) due to systemic sclerosis (SSc), it is now evident a further critical role of nailfold videocapilalroscopy (NVC) role to predict possible future clinical complications of the disease.
Crossectional associations have been made between both qualitative (NVC scleroderma patterns: “early”, “active”, “late”), quantitative capillaroscopic parameters (mainly number of capillaries and angiogenesis using validated scoring systems)) and clinical complications of SSc.
In this way a principal role of loss of capillaries has been attested in associations with pulmonary arterial hypertension, interstitial lung disease, peripheral vascular disease and severity of peripheral vascular, skin ulcers, heart and lung involvement assessed by the disease severity scale of Medsger.
Prospective predictive associations, in which baseline capillaroscopy (either qualitatively, either quantitatively assessed) is associated with future clinical complications are scarce but evidencing a putative role of capillaroscopy as biomarker in SSc. As matter of fact, SSc microangiopathy correlates with disease subsets and the severity of peripheral vascular, skin, and lung involvement; in particular, patients with the “late” NVC pattern showed an increased risk to have active disease and have moderate/severe skin or visceral involvement compared to patients with “early” and “active” NVC patterns.
Skin ulcers are a common vascular complication of SSc and seem now recognized in association with rapidly progressive capillary loss (at scoring) and the “late” NVC pattern, characterized by progressive avascular areas (loss of capillaries). An association with trophic lesions and loss of capillaries, as assessed by semiquantitative scoring has also been reported.
Very recently, in 130 SSc patients examined at entry and after 20 months of follow-up, the diffuse cutaneous SSc phenotype with avascular areas on NVC represented, among other factors (for example increased IL-6), the major risk factor for DU development.
A recent study, developed a capillaroscopic skin ulcer risk index (CSURI) that might predict the onset of DU by using NVC analysis in patients with SSc. However, this index has a complex formula, is time consuming and the authors admitted themself that even the simple decrease of capillary number alone is sufficient as marker.
Therefore, a more recent simple capillaroscopic index, (day-to-day DU index) prognostic for digital trophic skin lesions and based just on loss of capillaries alone (score), has been published showing high sensitivity and specificity.
DU have been associated with significantly reduced blood flow at fingertips [in addition, SSc patients with the scleroderma “active” and “late” NVC patterns showed decreased blood velocity (65.5 and 66.2% reduction, respectively) and in particular, the reduced blood velocity was significantly associated with capillary ramification (angiogenesis) and capillary loss.
Interestingly, and very recently, it was shown that endothelin receptor antagonism, may improve and stabilise the microvasculature in long-term treatment (from 1 up to 3 years) by modulating the structural modifications detected by NVC. After 1-3 years the number of capillaries was found significantly higher in the combination therapy group usung the endothelin receptor antagonism.
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Disclosure of Interest M. Cutolo Grant/Research support from: actelion, Conflict with: actelion