Predictors of human papillomavirus persistence or clearance after 5-aminolevulinic acid-based photodynamic therapy in patients with genital warts

Abstract Background Numerous studies have confirmed that 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) is an effective treatment for human papillomavirus-associated diseases. In this study, we evaluated the variables associated with human papillomavirus (HPV) persistence or clearance after ALA-PDT in patients with genital warts. Methods We performed a retrospective chart review of all patients with genital warts or subclinical HPV infection who received ALA-PDT treatment between January 2019 and December 2020 at Nanfang Hospital and Dermatology Hospital of Southern Medical University and analyzed the predictors of HPV persistence or clearance. HPV genotype and viral load assays were analyzed before treatment and after each session of photodynamic therapy. Results Multiple sexual partners, a history of recurrent HPV infection, and severe pain response during photodynamic therapy were associated with higher odds of viral persistence after three rounds of ALA-PDT. Infection with single strains of HPV, and mucosal and subclinical infection were more likely to be cleared after three rounds of photodynamic therapy. Conclusion Our findings suggest that patients with multiple sexual partners, a history of recurrent infections, and severe pain response during photodynamic therapy should undergo close surveillance and monitoring, and may need additional photodynamic therapy sessions. Infection with a single strain of HPV, and mucosal or subclinical infections are more likely to be cleared after three courses of ALA-PDT treatment. These findings may improve the efficiency of ALA-PDT in clinical practice.