Nailfold capillaroscopy findings in ILD patients: results from a single centre investigation.

Background: Nailfold capillary microscopy (NC) changes can be predictive of connective tissue disease (CTD), especially if associated with ANA positivity and Raynaud phenomenon. Interstitial lung disease (ILD) can be the first manifestation of CTD, before specific clinical signs or ANA positivity become evident. There are limited data on NC changes in patients with ILD as yet. Aim: to investigate NC changes in patients with ILD and no known CTD, and to correlate with ANA status and clinical variables. Patients and methods: 74 patients (27 F, 46 M) with interstitial lung disease (ILD) at first diagnosis were studied. ANA, detected by IIF on Hep2 cells, were considered positive at a titer >160. NC was performed by using a light microscope (Di-Li 2100, Distelkamp Elektronic, Germany). As comparison groups 116 patients with systemic lupus erythematosus (SLE) and 754 controls with normal pattern (NP) were included. Results: Among ILD patients, the most common diagnoses, confirmed by the ILD board, were IPF (32), idiopathic NSIP (19), IPAF (10) and COP (4). Pathological NC findings were seen in 30 (40%) ILD patients, 13 of them (43%) had NSIP pattern at HRCT. Frequency and intensity of NC changes in ILD patients were not associated with ANA status. Like SLE patients, ILD patients had more frequently impaired capillary filling and hemorrhage compared to NP controls. Conclusion: Patients with ILD seem to have NC changes with a similar morphology to SLE patients. NC alterations appear to be independent from ANA status and slightly more prevalent in NSIP patients.