Morphology of corneocytes from human nail plates

A technique is described which permits the isolation of individual corneocytes from the superficial layers of the human nail plates. Tesa-film D is used to strip off the cells. The tape is mounted on a glass slide, stained with a mixture of methylene blue and rhodamine B. The parameters were size (surface mu2), shape (regular, irregular), nuclear inclusions and trabeculae. Specimens were obtained from 3 groups of patients (finger- and toe nails): (1) 60 healthy subjects with normal nails, males and females, in 3 age-groups (babies, adults, aged); (2) 10 patients with fast growing nails with psoriasis vulgaris and psoriatic nail involvement; (3) 9 patients with slow growing nails with lichen planus with nail involvement including one patient with Zinser-Engman-Cole-syndrome (dyskeratosis congenita). The nail growth rate was determined with a dissecting microscope-technique. Corneocytes of the dorsal nail plates of normal nails are of irregular polyedrical shape, not nucleated and show distinct but irregular trabecular network. Within each age-group, corneocytes are of rather uniform size but increase significantly (p less than or equal to .001) with age (e.g., thumbin males: 597 vs. 920 vs. 1008 mu2). Accelerated nail plate growth results in smaller corneocytes, and slowed down nail plate growth in larger corneocytes. It is concluded that cell proliferation (and abnormal keratinization) has a measurable effect on the size of corneocytes from the nail plates.