Cerebral ischemic infarction in paroxysmal nocturnal hemoglobinuria report of 2 cases and updated review of 7 previously published patients.

BACKGROUND: Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal stem cell disorder, leading to a deficient biosynthesis of surface proteins in hematopoetic cells. Clinical symptoms consist of various combinations of intravascular hemolysis, bone marrow failure and mainly venous thrombotic events. Arterial thrombosis has been described only in a few cases.

METHODS: We report two patients with fatal ischemic strokes in PNH caused by arterial occlusion. In addition we also reviewed 7 previously reported cases in the literature and obtained follow-up information on 4 of the 5 survivors.

RESULTS: Both patients from our clinic had experienced hemoglobinuria and cytopenia prior to the vascular events but in one case diagnosis of PNH was only established after stroke onset. The causal role of PNH was supported by the absence of other vascular risk factors and by simultaneous symptoms of hemolysis and cytopenia. The diagnosis of PNH was confirmed by a positive result in flow cytometry. Despite extended therapeutic interventions, including antithrombotic treatment (with heparin or tirofiban) and decompressive hemicraniectomy both patients developed further thrombotic complications. The two patients died during their hospital stay from vascular or infectious complications. A review of all 9 published cases revealed that four patients died within a few weeks after the initial thrombotic event. No difference in treatment between patients with good or bad outcome was seen.

CONCLUSIONS: PNH is a rare cause of arterial stroke but it should be considered in young stroke patients with abnormal blood findings. As yet, there is no effective antithrombotic treatment.