Vascular damage is one of the key factors of systemic sclerosis (SSc), and nailfold videocapillaroscopy (NVC) is the recognized tool to study the microvascular bed, showing a high diagnostic sensitivity. NVC may provide valuable clinical information not only by detecting the “Early” pattern of microangiopathy, but it has been proposed as possible biomarker in SSc, correlating the vascular damage degree with the internal organ involvement (1-2).
In SSc, pathognomonic capillary abnormalities are present, characterizing the scleroderma-pattern of microangiopathy (1). Irregularly enlarged capillaries, giant capillaries (dilation of both capillary branches >50 microns), microhaemorrhages, reduction of capillary number, ramified (neoangiogenic) capillaries and disorganization of the vascular array are the major capillary abnormalities. However, these abnormalities are not present all together at the same time, and three different patterns of nailfold microvascular damage (namely “Early”, “Active” and “Late” scleroderma-patterns), correlating with the evolution of the microangiopathy, have been described and validated in scleroderma patients (3-6). The patterns represent three different consecutive phases of the microangiopathy itself (7). The factors influencing the time of evolution of the microangiopathy from the “Early” to the “Late” stage have not been determined; in some patients capillary abnormalities remain unchanged for several years, whereas in other patients there is fast evolution of the microangiopathy in a few months/years (7). The earliest stage of microangiopathy in SSc is characterized by the appearance of homogeneously enlarged capillaries (giant capillaries), which are the pathognomonic feature of the “Early” scleroderma-pattern; microhaemorrhages arise as a consequence of the damaged microvessel walls and, together with the presence of giant capillaries, are the recognized markers for the diagnosis of secondary Raynaud’s phenomenon. Subsequently, as the microangiopathy evolves, normal-shaped capillaries are seen to progressively decrease, with all capillaries becoming irregularly enlarged or “giant”; microhaemorrhages may occur concomitantly (as a consequence of giant capillary collapse), and the loss of capillary number becomes evident (“Active” scleroderma-pattern). In the advanced stage of the microangiopathy, both giant capillaries and microhaemorrhages disappear, and only few irregularly enlarged capillaries may be still present; the dramatic reduction in capillary number promotes large avascular (ischemic) areas, and a compensatory (although disturbed) neoangiogenesis with ramified capillaries induces a microvascular array disorganization (“Late” scleroderma-pattern) (1,7-8). This late phase of the microangiopathy has been found to correlate with greater organ involvement and disease severity (2,7).
“Early” NVC pattern: few (< 33%) enlarged/giant capillaries, few (< 33%) capillary haemorrhages, relatively well-preserved capillary distribution, absent or mild (<33%) loss of capillaries.
“Active” NVC pattern: frequent (> 33%) giant capillaries, frequent (> 33%) capillary haemorrhages, moderate (<66%) loss of capillaries, moderate (<66%) disorganisation of the capillary architecture, absent or few (< 33%) ramified capillaries.
“Late” NVC pattern: irregular enlargement of the capillaries, few (< 33%) or absent giant capillaries and haemorrhages, severe (>66%) loss of capillaries with avascular areas, disorganisation of the normal capillary array, ramified/bushy capillaries.
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Cutolo M Editor. Atlas of capillaroscopy in rheumatic diseases. Elsevier 2010, Milan, Italy.
Disclosure of Interest None Declared
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