Capillaroscopy may be predictive of novel future severe organ involvement in SSc, as attested by 2 independent cohorts.

Objective Investigation of the reliability of the qualitative and semiquantitative scoring of nailfold videocapillaroscopy (NVC) assessment between two raters in a systemic sclerosis (SSc) cohort. Methods Two raters from different centres blindly assessed the NVC images of 71 consecutive patients with SSc qualitatively as belonging to the scleroderma spectrum (SDS) category ('early', 'active', 'late' scleroderma pattern or 'scleroderma-like' pattern) or to the 'normal' category and semiquantitatively by calculating the mean score for capillary loss, giant capillaries, microhaemorrhages and capillary ramifi cations. Inter-rater/intrarater agreement was assessed by calculation of the proportion of agreement and by κ coeffi cients. Rater agreement of mean score values of hallmark parameters was assessed by intraclass correlation coeffi cients. Results The inter-rater/intrarater proportion of agreement to qualitatively assess an image as belonging to the SDS category or not was 90% and 96%, whereas the agreement to distinguish between only 'early', 'active' and 'late' scleroderma NVC patterns was 62% and 81%. The agreement of the semiquantitative scoring, as assessed by intraclass correlation coeffi cient, was 0.96 and 0.95 for capillary loss, 0.84 and 0.95 for giant capillaries, 0.90 and 0.95 for microhaemorrhages and 0.64 and 0.95 for capillary ramifi cations. Conclusions This is the fi rst study to demonstrate reliability of the qualitative and semiquantitative NVC assessment in an SSc cohort between raters at different centres. Reliability of NVC assessment is essential for use of this tool in multicentre SSc trials.

Rituximab appears to be well tolerated and may have potential efficacy for skin disease in dc-SSc.

This pilot study is the first demonstrating an association between baseline NVC patterns and future severe, peripheral vascular and lung involvement with stronger odds according to worsening scleroderma patterns. This may indicate a putative role of capillaroscopy as a biomarker.

This multicentre, international study showed moderate reliability of simple capillaroscopic definitions for describing morphology of capillaries by rheumatologists with varying levels of expertise. Novices were capable of distinguishing normal from abnormal capillaries by means of a 1-h training session. In future studies, the class not evaluable may be obsolete.