The Benign Cystic Lymphoepithelial Lesion of the Parotid Gland Is a Viral Reservoir in HIV Type 1-Infected Patients

Abstract

The presence of HIV-1 in cystic fluid aspirates from six cases of benign cystic lymphoepithelial lesion (BLL) of the parotid gland, a rare disorder affecting HIV-1-infected patients, has been investigated. HIV-1 p24 protein was present at a concentration ranging from 3 to 15 ng/ml, while it was undetectable in the peripheral blood of the same patients. The number of RNA copies of HIV-1 in the cystic fluids was high, ranging from 0.5 X 10⁷ to 7.2 X 10⁷ 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 microscopy of complete HIV-1 particles. The pathogenic mechanism leading to virus accumulation in the cystic fluid was studied by immunohistochemistry of tissue sections. p24 protein was associated with DRC-1+/S-100+ follicular dendritic reticulum cells, which were also present within the cystic cavities. Our findings are consistent with the possibility that the large amounts of virus present in the fluid derive from continuous shedding of HIV-1-infected cells from the surrounding lymphoid tissue.