Objective: A half year’s treatment is necessary to ascertain the effectiveness of finasteride on androgenic alopecia patients. To estimate the effect earlier, we analyzed the polymorphism of androgen receptor (AR) gene and change in serum level of certain hormones and cytokines within one month.
Methods: After PCR of blood cell DNA from patients (more than 1500), number of triplet repeats (CAG+GGC) in the first exon of AR gene was determined. Testosterone, dihydrotestosterone, IGF-1 and TGFβ-1 were determined by immunological assays before and one month after the drug treatment. Before and 6 months after the drug treatment, symptoms, typed by photographic method, were compared.
Results: When the number of triplet repeats was plotted against the degree of symptom improvement after treatment, a broad correlation between these variables was observed. Finasteride was more effective on the improvement of patient group with smaller repeat number in AR gene (40 or less) than that with larger one (41 or more). After the treatment for 1 to 2 months, serum dihydrotestosterone decreased in patients with smaller repeat number. On the other hand, in patients with larger repeat number, who were poor responder to finasteride, free testosterone increased but dihydrotestosterone did not markedly change.
Conclusion: Effect of finasteride on androgenic alopecia patients is able to be estimated earlier by determinations of AR gene polymorphism and by survey of androgenic hormone levels within a short-term (around one month).