2023, Vol. 27 ›› Issue (5): 690-694

Imiquimod combined with photodynamic therapy for hypertrophic scars: immune response and prognosis

Lu Huixiu, Cao Haiyu, Lou Dan, Li Jianying, Liu Hongyuan, Sun Jing   

Abstract: BACKGROUND: Hyperplasia scar is caused by dermal fibrosis due to fibroblast proliferation, uncontrolled growth and excessive collagen deposition. Both photodynamic therapy and imiquimod can inhibit fibroplasia. Imiquimod can further increase cell apoptosis and reduce the proliferation activity of fibroblasts by activating the immune response system.
OBJECTIVE: To study the effect of imiquimod combined with photodynamic therapy on the immune response and prognosis of patients with hypertrophic scars.
METHODS: A total of 110 patients with hypertrophic scars admitted to Shijiazhuang People’s Hospital from December 2017 to March 2020 were enrolled and randomly divided into a control group and a study group, with 55 patients in each group. Patients in the control group were given photodynamic therapy (every 10 days, four times in total) and those in the study group were treated with imiquimod cream (once a day for continuous 3 months) based on photodynamic therapy. The Vancouver Scar Scale was used to evaluate scar changes on day 2 after treatment. Clinical efficacy was evaluated and compared between the two groups of patients. The serum levels of interferon-γ, tumor necrosis factor-α, interleukin-2 and interleukin-6 were determined by enzyme-linked immunosorbent assay before and after treatment. The immunoturbidimetric method was used to determine the serum levels of IgA, IgG, and IgM in the two groups of patients. The occurrence of adverse reactions was recorded in the two groups.
RESULTS AND CONCLUSION: (1) Before treatment, there was no significant difference in softness, thickness, blood vessel distribution, and color score between the two groups (P > 0.05). After treatment, the softness, thickness, blood vessel distribution and color scores of the two groups were significantly reduced, and the above-mentioned scores in the study group were significantly lower than those in the control group (P < 0.001). (2) The clinical response rate of the study group was 96%, which was significantly higher than that of the control group (78%; P < 0.05). (3) Before treatment, there were no significant differences in the serum levels of interferon-γ, tumor necrosis factor-α, interleukin-2 and interleukin-6 between the two groups (P > 0.05). After treatment, the serum levels of interferon-γ, tumor necrosis factor-α, interleukin-2 and interleukin-6 were significantly reduced in the two groups, and the levels of the above-mentioned indicators in the study group were significantly lower than those in the control group (P < 0.001). (4) Before treatment, there was no significant difference in serum IgA, IgG and IgM levels between the two groups (P > 0.05). After treatment, the serum levels of IgA, IgG and IgM increased significantly in the two groups, and the serum levels of IgA, IgG and IgM in the study group were significantly higher than those in the control group (P < 0.05). (5) The total adverse reaction rate in the control group was 13%, which was significantly higher than that of the study group (2%; P < 0.05). (6) To conclude, imiquimod combined with photodynamic therapy has a good effect in the treatment of hypertrophic scars, which can significantly reduce inflammatory responses, improve immune function, and have fewer adverse reactions in such patients.
Key words: imiquimod, photodynamic therapy, hypertrophic scar, inflammatory response, immune function, immune response