Thrombotic thrombocytopenic purpura associated with human immunodeficiency virus type 1 (HIV-1) infection.

The cases of 14 patients with thrombotic thrombocytopenic purpura admitted to one institution after 1980 were reviewed. Three of the fourteen cases occurred in patients with the acquired immunodeficiency syndrome (AIDS)-related complex and one occurred in a patient with probable human immunodeficiency virus (HIV) infection. The diagnosis in all four cases had been made after 1985. The association of thrombotic thrombocytopenic purpura with HIV infection was judged to be statistically significant on the basis of the proportion of patients with AIDS among the general population of patients admitted to the same institution during the same period. The fact that this association is only now being recognized suggests that there may be a long incubation period for thrombotic thrombocytopenic purpura or that the association is a rare one recognized now only because of the increased number of persons with AIDS.