Autoantibodies in sporadic porphyria cutanea tarda.

In an investigation of autoimmune antibodies using indirect immunofluorescence and Western blot analysis in a group of porphyria cutanea tarda patients we did not find any cytosolic antibodies potentially able to inhibit uroporphyrinogen decarboxylase. Furthermore, no known etiological factors were present in any of our patients. We therefore consider the development of the recently reported autoantibody with a molecular weight of 40 kDa a reaction to infection with the hepatitis C virus. The origin of mostly antinuclear antibodies against liver antigens (50, 45 and 56 kDa), detected in seven patients, was not identified and their etiopathogenetic implications remain unknown.