Psoriatic hair follicle cells in culture.

Psoriatic human hair follicle keratinocytes can be brought to culture under the same conditions as normal control hair follicle keratinocytes. In comparison with control cultures derived from non-psoriatics there are significant differences. However, no significant differences are found between cultures derived from either psoriatic involved or uninvolved skin. Some characteristics of psoriatic lesions are also encountered in the cultures. However, in contrast to the situation in a psoriatic lesion, cultures of psoriatic keratinocytes differentiate to a higher extent than comparable control cultures. A psoriatic morphology is therefore not completely formed. Whether this is due to the absence of a psoriatic dermis or to the fact that differentiation in culture is incomplete remains to be investigated.