Nailfold capillaroscopy for the early diagnosis of the scleroderma spectrum of diseases in patients without Raynaud's phenomenon.

Abstract

The utility of nailfold capillaroscopy in the evaluation of patients without Raynaud's phenomenon is unclear. This study aims to compare the utility of nailfold capillaroscopy for the early diagnosis of the scleroderma-spectrum of diseases in patients who present with Raynaud's phenomenon, undifferentiated non-Raynaud's phenomenon features and positive systemic sclerosis-associated antibodies without scleroderma-spectrum of disease features. Eligible patients were divided into three referral criteria groups: (I) Raynaud's phenomenon; (II) Undifferentiated non-Raynaud's phenomenon features and (III) Positive systemic sclerosis-associated autoantibodies without features to suggest scleroderma-spectrum of diseases. This includes systemic sclerosis, mixed connective tissue disease and dermatomyositis. The association between baseline scleroderma pattern on nailfold capillaroscopy (systemic sclerosis-nailfold capillaroscopy) and final diagnosis at follow-up was determined using logistic regression analysis. Test characteristics of nailfold capillaroscopy were compared and stratified by referral groups. Of 95 patients followed-up for a mean of 1.6 years, 28 (29.5%) patients developed scleroderma-spectrum of diseases, 36 (37.9%) patients had suspected/other connective tissue disease and 27 (28.4%) patients had no connective tissue disease. Baseline systemic sclerosis-nailfold capillaroscopy was significantly associated with the development of scleroderma-spectrum of diseases in patients from Group I (odds ratio, 7.1, p = 0.01) and Group II (odds ratio 7.3, p = 0.005). In Group II patients, nailfold capillaroscopy had a sensitivity, specificity, positive and negative predictive values of 71.4%, 76.5%, 55.6% and 86.7%, respectively. Specificity (81.8%) and PPV (69.2%) were the highest in Group I patients. Nailfold capillaroscopy had the highest negative predictive value in Group III (100%), followed by Group II (86.7%) and Group I (78.3%) patients. In addition to evaluating patients with Raynaud's phenomenon, nailfold capillaroscopy was useful in the evaluation and exclusion of scleroderma-spectrum of diseases in patients with undifferentiated non-Raynaud phenomenon features and those with systemic sclerosis-associated antibodies without features to suggest scleroderma-spectrum of diseases.