Nailfold biopsy in scleroderma and related disorders. Correlation of histologic, capillaroscopic, and clinical data.

Although nailfold capillary abnormalities associated with connective tissue disease (CTD) have been studied by direct in vivo microscopy, little is known of the underlying histology and morphology of this tissue. This report summarizes light microscopic study of glycolmethacrylate embedded nailfold biopsies from 13 CTD patients (9 scleroderma, 2 CREST, 2 undifferentiated CTD), 2 subjects with Raynaud's phenomenon alone, and 9 normal volunteers of similar age and sex distribution. The most striking and consistent finding was the presence of globular, eosinophilic, PAS-positive deposits in the cuticles of 14 of 15 patients and none of the controls. This material, identified by immunofluorescent staining as serum protein exudates, was associated with pronounced parakeratosis and elevated epithelial mitotic activity. Capillary ectasia with thinning of the basement membrane was often present in CTD biopsies. Occasional signs of endothelial swelling and proliferation were encountered in both populations. Inflammatory changes were rarely seen. In quantitative comparison with control tissues, the superficial dermis from CTD patients contained significantly fewer capillaries, cutaneous nerve bundles, and interstitial fibroblasts per unit area and fewer papillary capillaries per unit of epidermal length. Measures of capillary density in sectioned tissue correlated well with the results of in vivo microscopic examination.