Background Pulmonary arterial hypertension (PAH) represents one of the main clinical expression of the vascular changes in Systemic Sclerosis (SSc). Many clinical and experimental evidences suggest that lung microvascular changes play a role in the pathogenesis of idiopathic PAH (IPAH) also.
Objectives The aim of this study is to investigate the presence of capillaroscopic abnormalities in patients with idiopathic PAH and to evaluate the differences in capillary naifold changes between patients with IPAH and SSc patients with and without PAH.
Methods 37 subjects with SSc (of whom 17 with PAH), 21 subjects with IPAH and 20 healthy subjects were recruited. PAH was diagnosed by right heart chateterization. Periungual capillaroscopy was performed in all recruited subjects, considering the following parameters: loops length and width, capillary density, microhemorrhages, avascular areas, neoangiogenesis. To define the pattern of capillary changes in IPAH and healthy subjects a semiquantitative scoring (normal, minor abnormalities, major abnormalities) was used, whereas in SSc subjects the capillary changes were defined as early, active and late pattern.
Results In all SSc subjects a capillaroscopic scleroderma pattern was found. Particularly, comparing SSc-PAH vs SSc-nonPAH we found an early pattern in 26,7% vs 50%, an active pattern in 66,6% vs 33,3% and a late pattern in a 6,6 vs 16,7% of subjects. None of IPAH subject presented a capillaroscopic scleroderma pattern, but interestingly in 36,4% of minor or major capillaroscopic changes were found. Analysing the single capillarocopic parameters, capillary density was lower in SSc subjects compared to the other groups; in SSc-PAH was lower than in SSc-nonPAH; in IPAH capillary density was lower compared to healthy control. Capillary width was higher in SSc patients compared to healthy and IPAH subjects, being higher in SSc-PAH compared to SSc-nonPAH. The number of megacapillaries, bushy capillaries and microhemorrages was significantly higher in patients with SSc-PAH compared to SSc-nonPAH patients. Interestingly, compared to healthy controls, the IPAH subjects presented a significantly lower capillary density and a significantly higher mean capillary width. Further, IPAH subjects presented a significant increase of number of microhemorrages and ectasic capillaries compared to healthy controls.
Conclusions Microcirculation alterations, and particularly the reduction of capillary density and the increase od capillary width appears to be more severe in SSc subjects with PAH compared to SSc subjects without PAH. Capillaroscopic changes can be present in IPAH subjects also. These data support the hypothesis that in SSc peripheral microcirculation changes can be related to the entity of pulmonary microcirculation changes and that an altered vascular lung remodelling could play a role in IPAH also.
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Disclosure of Interest None declared