Capillaroscopy Refines Scleroderma Diagnosis

Nailfold videocapillaroscopy can be used to distinguish between the primary and secondary forms of scleroderma, Dr. Maurizio Cutolo reported at the annual European Congress of Rheumatology.

In the past few years, capillaroscopy has been gaining momentum in Europe as a diagnostic tool and is now fairly widely used, Dr. Ariane Herrick, senior lecturer in rheumatology at the University of Manchester (England), said in an interview. While many clinicians use a simple ophthalmoscope to examine nail bed capillaries, a light stereomicroscope or, preferably, a videomicroscope affords superior visualization.

Dr. Cutolo and his associates at the research laboratory of the division of rheumatology at the University of Genoa (Italy) outlined the following findings that allow systemic sclerosis to be classified as early, active, or late disease, based on three distinct patterns of nailfold videocapillaroscopy:

▸ Giant capillaries. Homogeneously and irregularly enlarged microvascular loops are among the earliest and most striking features of Raynaud's phenomenon as a result of connective tissue disease. The peculiar looped shape of the enlarged capillaries is distinctive. The presence of even a single loop with a circumscribed or homogeneous diameter exceeding 50 μm should be considered as a potential marker of microangiopathy related to an early scleroderma-spectrum disorder, he said. In a recent study, giant capillaries were observed in 100% of patients with systemic sclerosis.

▸ Local microhemorrhages. These are also signs of microvascular damage in early disease. Local trauma must be excluded before the finding can be attributed to secondary Raynaud's phenomenon.

▸ Edema. This is frequently observed at the level of the dermal papillae, mainly in active cases of systemic sclerosis, Dr. Cutolo said.

▸ Angiogenesis. The appearance of capillary neoformation, a sign of late disease, can widely vary. One characteristic form of angiogenesis includes highly tortuous and arborized capillary loop clusters, often surrounded by dropout of normal capillary loops. The main morphologic hallmark in angiogenesis is the clustering of tortuous capillaries with pronounced heterogeneity, including thin or large meandering and bushy capillaries. In distinction, coiled capillaries are the morphologic hallmark of angiogenesis in the elongated papillae of psoriatic plaque.

▸ Loss of capillaries and avascular areas. A reduced number of capillary loops—less than 30 observed in 5 mm in the distal row of the nailfold—should be considered highly specific for secondary Raynaud's phenomenon. In advanced systemic sclerosis, only 20% of the capillaries may have a normal appearance on nailfold videocapillaroscopy. Extensive loss of capillaries may result in large avascular areas. Rapidly progressive nail bed capillary loss is a strong indicator of systemic sclerosis even in new-onset Raynaud's.

Both Dr. Herrick and Dr. Cutolo are investigating more advanced methods of capillaroscopy that involve digitization of the images. "We hope that the new modifications and developments in capillaroscopy will allow us to track changes in the capillaries over time," they said.

Giant capillaries are an early sign of secondary Raynaud's phenomenon.

Also, in early disease, hemorrhages mark microvascular damage.

Loss of capillaries is shown in the nailfold of a Raynaud's patient. Photos courtesy Maurizio Cutolo