Thrombotic complications in patients infected with HIV in the era of highly active antiretroviral therapy: a case series.

BACKGROUND: Recent reports suggest that patients infected with human immunodeficiency virus (HIV) may have an increased risk of developing thrombosis, but the etiology, risk factors, and clinical course remain largely undefined, with few descriptive case series.
METHODS: We identified 30 patients from an HIV outpatient clinic (treatment population, 650 persons) who had had a total of 43 venous or arterial thromboses during 1996-2002. Data pertaining to demographic characteristics, medical history, thrombosis presentation, and clinical outcomes were abstracted from patient medical records.
RESULTS: The median patient age at the time of thrombosis was 43 years. Although the presence of persistent antibody to phospholipids was the most common abnormal finding in the laboratory, evaluation of thrombophilia, cases of low levels of proteins C and S and antithrombin III, and elevated levels of factor VIII and homocysteine were also identified. Seventy-seven percent of the patients smoked cigarettes, 57% had dyslipidemia, and 43% had a malignancy (most commonly Kaposi sarcoma). Although the Centers for Disease Control and Prevention (CDC) classification for 16 patients (53%) was C3, most showed evidence of immune reconstitution (median CD4 cell count, 290 cells/ mu L) and control of the virus (median HIV load, 2290 copies/mL). Lower extremity, deep vein thrombosis and pulmonary emboli accounted for 66% of all thrombotic events. The median time to diagnosis of thrombosis was 1 day (range, 3 h to 3 weeks).
CONCLUSIONS: Patients in this series were characterized by a relatively young age at the time of thrombosis, a predominance of elevated levels of lipids, a history of malignancy, and an advanced CDC HIV classification but not by a low CD4 cell count or an elevated HIV load.