The benign cystic lymphoepithelial lesion of the parotid gland is a viral reservoir in HIV type 1-infected patients

The presence of HIV-1 in cystic fluid aspirates from six cases of benign cy stic lymphoepithelial lesion (BLL) of the parotid gland, a rare disorder af fecting HIV-1-infected patients, has been investigated. HIV-1 p24 protein w as present at a concentration ranging from 3 to 15 ng/ml, while it was unde tectable in the peripheral blood of the same patients, The number of RNA co pies of HIV-1 in the cystic fluids was high, ranging from 0.5 x 10(7) to 7. 2 x 10(7) RNA copies/ml. BLL cystic fluid aspirates, despite the high level of HIV-1 RNA, were found to contain only a few infectious virions, The low infectivity correlated with the infrequent detection by electron microscop y of complete HIV-1 particles. The pathogenic mechanism leading to virus ac cumulation in the cystic fluid was studied by immunohistochemistry of tissu e sections. p24 protein was associated with DRC-1(+)/S-100(+) follicular de ndritic reticulum cells, which were also present within the cystic cavities , Our findings are consistent with the possibility that the large amounts o f virus present in the fluid derive from continuous shedding of HIV-1-infec ted cells from the surrounding lymphoid tissue.