Study of certain clinical variables in patients with psoriasis and their relation to DNA content of keratinocytes.

BACKGROUND In a previous study of 26 patients with psoriasis we analyzed cytophotometrically the nuclear DNA content of the germinative compartment of involved and uninvolved skin by means of the Feulgen technique. These subjects were classified into three groups according to their DNA profile. Group 1 had a monomodal diploid profile, group 2 showed a significantly increased 2C-4C population, and group 3 demonstrated high proportions of 4C and hyperdiploid keratinocytes. OBJECTIVE Our purpose was to analyze clinical variables implicated in the development of psoriasis in reference to the three groups. METHODS Nuclear DNA content of each group by quantitative histochemical studies was analyzed and correlated with variables such as chronologic age, sex, age at onset, duration of flare during the study, stress, and the Koebner phenomenon. RESULTS No significant differences in DNA profile were observed in the involved epidermis among the clinical variables. The only differences in the uninvolved skin pertained to the duration of the flare, where a statistically significant difference was observed between groups 1 and 3 in the basal (p < or = 0.0459) and suprabasal keratinocytes (p < or = 0.06), and in the Koebner phenomenon, which was induced in all subjects (100%) in groups 2 and 3 and in only 44% of subjects in group 1. CONCLUSION Uninvolved skin of patients with psoriasis should be included in analysis of the clinical behavior of the disease. Furthermore, the Koebner phenomenon is a good clinical indicator of the DNA profile of these subjects.