Nailfold videocapillaroscopy micro-haemorrhage and giant capillary counting as an accurate approach for a steady state definition of disease activity in systemic sclerosis

Introduction: Nailfold videocapillaroscopy (NVC) in systemic sclerosis (SSc) is a procedure commonly used for patient classification and subsetting, but not to define disease activity (DA). This study aimed to evaluate whether the number of micro -haemorrhages (MHE), micro thrombosis (MT), giant capillaries (GC), and normal/dilated capillaries (Cs) in NVC could predict DA in SSc. Methods: Eight finger NVC was performed in 107 patients with SSc, and the total number of MHE/MT, GC, and the mean number of Cs were counted and defined as number of micro haemorrhages (NEMO), GC and Cs scores, respectively. The European Scleroderma Study Group (ESSG) index constituted the gold standard for DA assessmer and scores >= 3.5 and = 3 were considered indicative of high and moderate activity, respectively. Results: NEMO and GC scores were positively correlated with ESSG index (R = 0.65, P <0.0001, and R = 0.47, P <0.0001 respectively), whilst Cs score showed a negative correlation with that DA index (R = 0.30, P <0.001). The area under the curve (AUC) of receiver operating characteristic plots, obtained by NEMO score sensitivity and specificity values in classifying patients with ESSG index >= 3.5, was significantly higher than the corresponding AUC derived from either GC or Cs scores (P <0.03 and P <0.0006, respectively). A modified score, defined by the presence of a given number of MHE/MT and GC, had a good performance in classifying active patients (ESSG index >= 3 sensitivity 95.1%, specificity 84.8 /6, accuracy 88.796). Conclusions: MHE/MT and GC appear to be good indicators of DA in SSc, and enhances the role of NVC as an easy technique to identify active patients.