A test result that is negative when the person is actually or truly positive. Occasionally the test may be falsely negative. In other words the test is negative but the person is actually HIV infected. This may be due to the window period or to some technical problem. On rare occasions it may be due to very severe immune deficiency.

Also called body fat redistribution syndrome (BFR). Changes in body fat distribution, sometimes referred to as "lipodystrophy syndrome" or "fat redistribution syndrome," have been observed in patients taking protease inhibitors. Changes may include visceral fat accumulation ("protease paunch"), dorsocervical fat accumulation ('buffalo hump'), and extremity wasting with venous prominence, facial thinning, breast enlargement, and lipomatosis.

Drifting dark spots within the field of vision. Floaters can be caused by infection with Cytomegalovirus (CMV) retinitis, but also can appear in persons as a normal part of the aging process.

An antibody that binds to an antigen and has an effect. For example, neutralizing antibodies inactivate HIV or prevent it from infecting other cells.

One of a group of primitive, nonvascular organisms including mushrooms, yeasts, rusts, and moulds.