Background Nailfold capillary microscopy (NCM) has been shown to be associated with disease severity and internal organ involvement in non-consecutive systemic sclerosis (SSc) cohorts. NCM may help in early recognition of connective tissue disease (CTD) but it is unclear to which extent NCM abnormalities occur in several CTD and whether these are associated with organ involvement.
Objectives To assess NCM in consecutive patients with Raynaud's phenomenon (RP) and whether these are associated with signs of organ involvement.
Methods NCM was assessed in consecutive patients with RP (n=759) by widefield videocapillaroscopy, according to standardized procedures at a dedicated vascular laboratory by trained and experienced technicians. The pattern was classified as normal (n=325), non-specific (n=188) or SSc pattern (early (n=106), active (n=140) or late (n=0) based on the Cutolo patterns). Potential pulmonary involvement was defined as forced vital capacity or diffusion capacity <70%. Gastro-intestinal involvement as scintigraphically (Tc-99M colloid) oesophagus dysmotility. Skin involvement as puffy fingers or sclerodactyly.
Patients were classified as primary RP (normal NCM and negative serology, n=226) or secondary RP (abnormal NCM and/or serology) groups: early SSc (n=195), SSc (n=40), incomplete Sjögren's syndrome (iSS, n=5), primary SS (pSS, n=30), incomplete systemic lupus erythematodes (iSLE, n=42), SLE (n=30), mixed CTD (MCTD, n=7), rheumatoid arthritis (RA, n=15) or when not meeting criteria as other (n=169). None were diagnosed with polymyositis or dermatomyositis.
Results SSc pattern was observed in 33% of patients with pSS, 17% SLE, 71% MCTD and 13% RA. Pulmonary, oesophageal and skin involvement was more frequent in secondary RP patients with an SSc pattern, even when analysing only those fulfilling definite criteria for CTD or after exclusion of early SSc and SSc patients. For secondary RP patients, absence of an SSc NCM pattern had a high negative predictive value for pulmonary (92%), oesophageal (91%) and skin (96%) involvement, while positive predictive values were low.
Conclusions SSc pattern on NCM is common in CTD patients and is associated with frequent prevalence of organ involvement, even in the absence of (early) SSc. Although this was a retrospective cohort, these data underline the importance of assessing NCM in RP patients to evaluate the risk for organ involvement in CTD other than SSc, already in early disease stages.
Disclosure of Interest None declared