Examination of nailfold videocapillaroscopy findings in ANCA-associated vasculitis

The objective of this study was to evaluate nailfold videocapillaroscopy (NVC) as a useful tool for assessing the disease activity of ANCA-associated vasculitis (AAV).

This study enrolled 51 patients with AAV and 21 healthy controls. We scored NVC findings semiquantitatively, and compared them between AAV patients and controls. We examined the association of NVC findings with disease activity indicators, histopathological findings of skin biopsies, and high-resolution CT (HRCT) scores in AAV. Additionally, we repeatedly rated the NVC findings 3 months after immunosuppressive therapy.

Of the 51 enrolled patients, 36 (70.6%) showed a microangiopathy pattern and 4 (7.8%) showed a scleroderma pattern in AAV. The scores for microhaemorrhage, capillary loss, neoangiogenesis, and tortuosity were significantly higher in the AAV group than in the control group. NVC abnormalities correlated with the severity of skin, lung and kidney involvement. The scores of giant capillaries significantly correlated with the total BVAS and the chest BVAS; the scores of capillary loss correlated with the chest BVAS and the renal BVAS. The scores of microhaemorrhage significantly correlated with perivascular inflammatory cell infiltrations in the upper dermis of the purpura and tended to correlate with the total ground-glass opacity and consolidation scores on HRCT. In addition, capillary loss scores had a significant positive correlation with serum creatinine levels. Additionally, the microhaemorrhage scores were significantly reduced after 3 months of immunosuppressive therapy.

In AAV patients, NVC abnormalities are significantly associated with disease severity. This result suggests that NVC is a useful tool for assessing the disease activity and treatment response in AAV.