FOXP3+regulatory and TIA-1+cytotoxic T lymphocytes in HIV-associated Hodgkin lymphoma

Human immunodeficiency virus (HIV) infects CD4+ lymphocytes, leading to a development of malignant lymphomas, such as HIV-associated Hodgkin Lymphoma (HIV-HL). This study aimed to assess the differences in cellular composition of the inflammatory reactive background of HIV-HLs. We examined infiltrating T lymphocytes, specifically regulatory T cells, cytotoxic cells, Epstein-Barr virus (EBV) related antigens and HIV-receptor CCR5. In all HIV-HL cases, Hodgkin and Reed-Sternberg (HRS) cells showed EBER1 expression, LMP-1 staining positivity and EBNA-2 staining negativity, except for one case which showed LMP-1 staining negativity. Our histological findings indicate the percentage of CD8+, TIA-1+ lymphocytes was significantly higher in HIV-HL than in non-HIV-HL cases (P < 0.05). On the other hand, the percentage of CD4+, FOXP3+ lymphocytes was significantly lower in HIV-HL than in non-HIV-HL cases (P < 0.05) but present. The percentage of CCR5+ lymphocytes was significantly lower in HIV-HL than in non-HIV-HL cases (P < 0.05). Usually, CD4+ and CCR5+ lymphocytes are reported to be rarely detected in HIV-associated non-Hodgkin lymphomas, but the presence of CD4+ and/or FOXP3+ lymphocytes may be implicated in the pathogenesis of HL. In addition, although additional CD8+ lymphocytes are probably not EBV-LMP specific cytotoxic T-cells, these lymphocytes may also well be involved in the pathogenesis of HIV-HL.