Antibody masking renders HIV-1 resistant to cationic membrane filtration through alteration of its electrostatic characteristics.

Previously, it was demonstrated that any human immunodeficiency virus type 1 (HIV-1) strain proliferating in peripheral blood mononuclear cells (PBMCs) in vitro, and resuspended in seronegative plasma, could be captured efficiently (mean > 95%) by a porous polypropylene (PP) membrane modified cationically. We investigated if this cationic membrane could capture HIV-1 obtained from seropositive plasma, and confirmed whether this membrane was effective for the preparation of safe plasma products against HIV-1 transmission. Thirty-six seropositive plasma samples derived from HIV-1 positive cohorts in New York and Lusaka (Republic of Zambia), including 18 cases of acquired immunodeficiency syndrome (AIDS) related complex, AIDS and five terminal cases of AIDS, were filtered through the cationic membrane to determine the reduction of RNA concentration, the gag p24 concentration, and infectious titer.