Objectives: The progression of immunosuppression in human immunodeficiency virus (HIV)+ women has been correlated with elevated incidence of squamous intraepithelial lesions (SIL), probably indicating the role of local immune milieu. In this study, we analysed S100, and HLA class II molecule expression in cervical biopsies according to HIV status, to the severity of SIL and to human papillomavirus (HPV) type.
Methods: Biopsies from 34 HIV+ and 44 HIV- patients with normal cervix or low- or high-grade SIL were studied. Langerhans' cells (LC) (S100), HLA class II and HLA-DQ molecules were evaluated by immunohistochemistry. HPV detection was performed using polymerase chain reaction (PCR). For statistical analysis Mann-Whitney (P< or =0.05) and Spearman test were used.
Results: Epithelial S100 and HLA class II density were significantly increased with the severity of lesion (P=0.032; P=0.005). Epithelial S100+ increased in HPV+ (P=0.038), and HLA class II density decreased in HPV 16+ (P=0.035) or 18+ (P<0.0001) samples. HIV infection was associated with increased stromal S100+ (P=0.0005) and decreased HLA class II densities (P=0.0001). Decreased stromal S100+ was observed in women with CD4<500 cells/microl (P=0.050). Among HIV+ patients with SIL, the lowest S100 and epithelial HLA class II densities were detected in women with CD4<200 cells/microl (P=0.045).
Conclusions: After the establishment of AIDS, increased numbers of immature LCs and a reduction in HLA class II occurred, possibly turning the cervical milieu more favourable to HPV persistence. HPV 16 and 18 infections may interfere with the antigen presenting activity, possibly as an evasion mechanism.