Nailfold videocapillaroscopy micro-haemorrhage and giant capillary counting as an accurate approach for a steady state definition of disease activity in systemic sclerosis.
IntroductionNailfold videocapillaroscopy (NVC) in systemic sclerosis (SSc) is a procedure commonly used for patient classification and sub-setting, 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.MethodsEight 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 assessment, and scores ¿3.5 and¿=¿3 were considered indicative of high and moderate activity respectively.ResultsNEMO 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 given number of MHE/MT and GC, had a good performance in classifying active patients (ESSG index ¿3, sensitivity 95.1%, specificity 84.8%, accuracy 88.7%).ConclusionsMHE/MT and GC appear to be good indicators of DA in SSc, and enhances the role of NVC as a easy technique to identify active patients.