Follicle lysis in HIV-free lymphoid tissues.

Follicle lysis (FL), the 'moth-eaten' degeneration of follicular dendritic cells (FDCs), previously regarded as specific for HIV-infected lymph follicles, was later claimed to exist in HIV-free patients. This study was performed to clarify the differences between HIV-free and HIV-induced FL. HIV-free and HIV-infected lymphoid tissues were analyzed immunohistologically. Most of HIV-free FLs were shown to lack the dark zones, the areas in germinal center composed mostly of much larger and clumped noncleaved cells, whereas HIV-induced FL in persistent generalized lymphadenopathy (PGL) lymph nodes included highly proliferative dark zones. Thus, FL in HIV-free lymphoid organs was suggested to be a physiological degenerative process with poor proliferative activity, while FL in PGL nodes includes two processes, FDC degeneration and B lymphocyte proliferation.