Association of Nail Dystrophy With Accrued Damage and Capillaroscopic Abnormalities in Systemic Lupus Erythematosus.

BACKGROUND

There are some nail abnormalities described in systemic lupus erythematosus (SLE).

OBJECTIVES

The aim of this study was to evaluate the association between nail dystrophy (ND) and disease activity, accrued organ damage, capillaroscopic abnormalities, autoantibodies, and some markers of endothelial cell activation in patients with SLE.

METHODS

This was a cross-sectional study of SLE patients from a rheumatology clinic in a tertiary care hospital. Patients were allocated in groups, according to the presence or absence of ND. Demographics, clinical data, disease activity, accrued damage, serology, nailfold capillaroscopy characteristics, serum levels of anti-endothelial cell antibodies, and plasma levels of endothelin 1 were compared between groups. Disease activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index 2000 index and accrued organ damage by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index.

RESULTS

Sixty-one patients were included; 50 patients (82%) were female. Thirty-two patients (52.5%) showed ND, and 29 did not. Besides a more frequent use of cyclophosphamide (46.9% vs 20.7%; P = 0.03) in the ND group, clinical features were similar. A greater organ damage was found in patients with ND (median Systemic Lupus International Collaborating Clinics/American College of Rheumatology index = 0.5, minimum = 0, maximum = 6) than in patients without ND (0, 0, 3, respectively; P = 0.04); specifically, only the skin domain was associated with ND (P = 0.04). Onycholysis (40.6%) and longitudinal ridging (25%) were the most frequent nail changes. Nailfold capillaroscopy changes were more frequent in ND patients (40.6%) than in control subjects (13.8%) (P = 0.02). The most frequent nailfold capillaroscopy findings in the ND group were enlarged capillaries (40.6%) and microhemorrhages (12.5%). There was no association between ND and the autoantibody profile, plasma endothelin 1, or serum anti-endothelial cell antibodies.

CONCLUSIONS

Nail dystrophy was associated with higher accrued organ damage and the presence of capillaroscopic abnormalities. This suggests that ND might be related to chronic microvascular damage.