Antinuclear antibodies in patients with polymorphic light eruption: a long-term follow-up study

Abstract

Previous studies have shown elevated titres of antinuclear antibodies (ANA) in 2.9-19% of patients with polymorphic light eruption (PLE). A diagnosis of lupus erythematosus (LE) was finally established in some of these ANA-positive patients. To investigate whether the presence of ANA in patients with PLE merely represents an epiphenomenon or is associated with an increased risk of eventual progression to LE. We identified 472 patients with PLE who had received prophylactic photo(chemo)therapy between 1986 and 2003 and were routinely tested for the presence of ANA. All ANA-positive (ANA titre of>or=1:80) patients were asked to attend for a follow-up examination comprising a medical history, complete skin inspection and a detailed laboratory analysis including ANA and antibodies against extractable nuclear antigens. Of all the patients, 55 (11.7%) were found to be ANA positive on one or several occasions, and three (0.6%) also had antibodies to SS-A/Ro. Thirty-nine (71%) of all ANA-positive patients including all Ro+ subjects were available for follow-up after a median follow-up period of 8 years (interquartile range 5-11.5). Twenty-five patients showed persistence of ANA positivity with a median titre of 1:160 (range 1:80-1:640), whereas in 14 patients ANA titres had returned to normal levels. None of the patients revealed additional clinical, histopathological or laboratory abnormalities suggestive of LE. After a median follow-up period of 8 years none of the ANA-positive patients developed LE. Our findings indicate that PLE is a benign disease without tendency to progress to LE.