Epidermis is the origin of high creatine kinase levels in skin blister fluid.

Creatine kinase (CK) isoenzyme, CK-BB, known as the brain fraction, is not normally present in serum but predominates in several normal and malignant tissues and body fluids. We recently reported increased CK-BB levels in suction blister fluid. In the present study the cellular origin of the enzyme in skin was studied from homogenates of blister top epidermis and blister base dermis as well as from homogenates of split skin dermatome shavings and isolated keratinocytes. The CK-BB in human skin was derived almost exclusively from the epidermis. Enzyme determinations from various spontaneous bullae suggest that all types of skin blisters initially contain high CK-BB levels.