Patients with paroxysmal nocturnal hemoglobinuria (PNH) associated with bone marrow disorder have notably inferior survival, according to a new study presented at the 64th ASH Annual Meeting and Exposition. These patients also rarely received standard agents used to treat classic PNH.

Bone marrow disorder-associated PNH, which is 1 of 3 types of PNH, remains poorly studied, and almost all research about complement inhibitors focuses on the classical form of the disease.

To analyze survival in patients with bone marrow disorder-associated PNH compared with classical PNH, a team of researchers led by Elia Ixel Apodaca, MD, MSc, from Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, in Mexico City, Mexico, conducted a multicenter retrospective study between March 1990 and January 2022 in 3 hospitals in Mexico. 

They analyzed 100 patients, aged 37 to 59 years. Most patients (72%) had classical PNH, whereas 28 had bone marrow disorder-associated PNH. 

Read more about the diagnosis of PNH

The researchers recorded differences between the 2 types of disease in median lactate dehydrogenase levels, clone size, and median platelet levels. 

Almost one-quarter (21.42%) of patients with bone marrow disorder-associated PNH had a high disease burden, which is a frequent indication of complement inhibitor use in patients with classic disease.

However, while the use of complement inhibitor was reported in 30.55% of patients with classic PNH, it was reported in only 1 patient (3.57%) with bone marrow disorder-associated PNH. 

Anticoagulation treatment was also more frequently used among patients with classic PNH. On the contrary, the vast majority (96.43%) of patients with bone marrow disorder-associated PNH used bone marrow failure treatment such as immunosuppressants and/or androgens.

Read more about PNH complications

The researchers also reported that the overall survival of patients with bone marrow disorder-associated PNH was considerably lower that that of patients with classic PNH and the lack of complement inhibitor or anticoagulation treatment was independently associated with increased mortality.

Because no specific treatment beyond immunosuppression and/or androgens has been defined in bone marrow disorder-associated PNH, the “use of complement inhibitor therapy could be a promising option,” according to the researchers.

Reference

Ramirez LGC, Vieyra AS, Alvarez J, et al. Multi-center analysis of clinical characteristics, outcomes and overall survival of an under-studied entity: paroxysmal nocturnal hemoglobinuria associated with bone marrow disorder. 64th ASH Annual Meeting and Exposition. New Orleans, LA, December 10-13, 2022. Poster number 3891.