Sensitization of immune cells following hexylaminolevulinate photodynamic therapy of cervical intraepithelial neoplasia.

BACKGROUND

Effects of photodynamic therapy (PDT) were tested with respect to immune cell stimulation in cervical intraepithelial neoplasia (CIN).

METHODS

A patient with CIN received hexaminolevulinate (HAL) and subsequent PDT. These data were compared to a placebo PDT patient and a healthy HPV16-vaccinated donor. Isolation of peripheral blood mononuclear cells (PBMC) was performed before PDT and at 4 different time points after PDT. The proliferation of these PBMC was tested by [3H]thymidine incorporation following stimulation with control or HPV16-L1 peptides. Potential effects on the CD4+ and CD8+ cell subsets were analysed.

RESULTS

The data revealed an unchanged or decreased proliferation of HPV16-L1 peptide-stimulated PBMC as compared to placebo patient. HPV16-L1 peptide incubation of PBMC from the HAL patient demonstrated significant proliferative capacity after PDT. The CD4+ and CD8+ T cell populations in placebo patient were slightly increased after HPV16-L1 peptide administration at each time point. Mixed results were obtained for CD4+ cells as compared to controls and nearly unchanged amounts of CD8+ cells were detectable following HPV16-L1 peptide exposure of PBMC from the HAL/PDT-treated patient.

CONCLUSIONS

These findings suggest a T cell reaction from CIN patients during repeated HAL/PDT treatment. However, further immune cell populations might be involved during PDT.