A new analysis of data from the International Paroxysmal Nocturnal Hemoglobinuria (PNH) Registry identified and confirmed several risk factors for thromboembolic events (TE), a leading cause of death for patients with PNH.
The study results, published in the Annals of Hematology, identified a prior history of TE, 30% or greater glycosylphosphatidylinositol-negative granulocytes, or lactate dehydrogenase 1.5 or more times upper limit of normal plus 2 or more high disease activity criteria as factors that increase the risk of TE in these patients.
“Thromboembolic events are the leading cause of death in patients with PNH, accounting for 40% to 67% of deaths before the complement inhibition era, with a 5‐year mortality rate of approximately 30%,” the authors wrote. “In the current study, we analyzed patient data from the Registry to identify risk factors for TE and evaluate the odds of TE in the presence of specific disease characteristics and clinical parameters.”
The research team used the PNH International Registry to analyze patient data with a cutoff date of July 8, 2019. Fifty-seven patients who were not treated with complement inhibitors at enrollment and who had 1 or more TE after enrollment were included and were matched with 189 untreated controls without TEs.
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Patient demographics, clinical parameters, TEs, and other major adverse vascular events were collected for all cases and controls.
The results revealed that a history of TE, 30% or greater glycosylphosphatidylinositol-negative granulocytes, and lactate dehydrogenase 1.5 or more times upper limit of normal plus 2 or more high disease activity criteria were risk factors for TE in this patient group, and that those with a history of TE were at higher risk regardless of the use of anticoagulants.
The authors noted that these findings confirm those of other studies, and that additional investigation into risk factors for TE in these patients could help inform treatment decisions and improve outcomes.
Höchsmann B, Peffault de Latour R, Hill A, et al. Risk factors for thromboembolic events in patients with paroxysmal nocturnal hemoglobinuria (PNH): a nested case-control study in the International PNH Registry. Ann Hematol. Published online September 5, 2023. doi.10.1007/s00277-023-05402-3