The Effect of Narrowband Ultraviolet B Phototherapy on Antinuclear Antibody Status: A Case-Control Study.

BACKGROUND Narrowband ultraviolet B (NB-UVB) phototherapy has become a widely used, standard treatment modality in dermatology. The effect of 8-methoxypsoralen plus ultraviolet A on antinuclear antibody (ANA) formation has been investigated extensively, but there are very scarce data about the potential risk of NB-UVB phototherapy inducing production of ANAs. The aims of this study were evaluation of ANA status before and after NB-UVB treatment and comparison of ANA status with the healthy control group. METHODS Phototherapy unit database was used to identify patients who had received whole body NB-UVB treatment. Analyses of ANA were performed twice in the study group that were before initiation of the NB-UVB phototherapy and after cessation of the therapy. Also, ANAs were screened in the control group. RESULTS A total of 95 patients (50 males and 45 females; mean age: 43.03 ± 13.40) treated with NB-UVB radiation and 90 age- and sex-matched controls were included in the study. Thirteen patients (13.7%) were found to develop ANAs at the end of the treatment. ANA positivity was significantly more common in patients after phototherapy than in patients before phototherapy and than in the control group. None of the patients in the positive ANA group was diagnosed with any connective tissue diseases. CONCLUSION This study revealed that ANA positivity increased after NB-UVB phototherapy. However, it did not provide evidence for increased connective tissue disease risk. Therefore, ANA might not need to be routinely checked before treatment unless the patients have signs and symptoms indicating autoimmune diseases.