Thrombolytic therapy is effective in paroxysmal nocturnal hemoglobinuria: a series of nine patients and a review of the literature

Abstract

Background: Thrombosis is the major risk factor for death in patients with paroxysmal nocturnal hemoglobinuria. Previous case reports indicate that venous thrombosis in patients with paroxysmal nocturnal hemoglobinuria is amenable to thrombolysis.

Design and methods: We reviewed the outcome of thrombolytic therapy for patients with paroxysmal nocturnal hemoglobinuria who had thromboses refractory to anticoagulation at our institutions.

Results: In this study of 41 patients who had at least one thrombotic event, we confirmed a very high incidence of recurrence despite anticoagulation. Nine patients with thrombosis were regarded as eligible for administration of intravenous tissue plasminogen activator, which was effective in reversing thrombi in all of 15 occasions in which it was given. Serious hemorrhagic complications developed in three cases. At last follow-up visit, of the nine patients treated, three had died, and six were in very good to excellent condition in terms of clinical outcome and radiological findings. The only patient in whom thrombolysis may have contributed to a fatal outcome also had complications of "heparin induced thrombocytopenia with thrombosis", which we diagnosed in three additional patients. In our review of the literature, nine out of 15 patients treated with thrombolysis have had a good outcome.

Conclusions: Although it is associated with a significant but manageable risk of bleeding, systemic thrombolysis is a highly effective treatment for reversing venous thromboses in patients with paroxysmal nocturnal hemoglobinuria.

Figure 1

Kaplan-Meier curve representing recurrent thrombotic events in patients already treated for one thrombotic event. Thirty-five patients were followed for a median of 2.2 years. Median time to recurrence was approximately 4.5 years, and 14 patients eventually had recurrences. To our knowledge, all of these patients were supposed to have been on anticoagulation after their initial thrombosis, with the exception of one patient who was briefly instructed to stop warfarin for a procedure shortly before a recurrent thrombosis.

Figure 2

Selected radiological images. (A) Portal vein thrombosis, patient 2. (B) Portal vein, patient 2, after tPA (C) Middle hepatic vein thrombosis, patient 2. (D) Middle hepatic vein, patient 2, after tPA, with restored flow (E), demonstrated by Doppler. (F) Magnetic resonance (MR) venogram, patient 2. (G) MR venogram, patient 2, after tPA. (H) MR venogram, patient 4, showing extensive venous occlusions. (I) Head computed tomography, patient 4, after tPA, showing a subdural hematoma. Arrows indicate sites of thrombosis in panels A,C, F, and H, and indicate the hematoma in panel I.