Researchers have identified a number of cases of hemolytic paroxysmal nocturnal hemoglobinuria (PNH) in patients with myeloid neoplasms—a rare combination that requires specific therapeutic management. They reported their findings in a letter sent to the editor of the British Journal of Hematology. 

Epidemiological studies reveal that concurrent hemolytic PNH in patients with myeloid neoplasms is extremely rare. The research team hence sought to characterize the clinical course of patients who have this combination in the absence of pre-existing PNH. 

They retrospectively studied the clinical files of patients who were referred to the French Reference Center for Aplastic Anemia. In addition, they sent 2 waves of emails to more than 100 specialized physicians in France. Their goal was to obtain as much information about as many patients as possible who had a concurrent diagnosis of PNH and myeloid neoplasms. The researchers took steps to reduce their chances of selecting patients with a clonal evolution of PNH by excluding patients with a prior history of aplastic/hemolytic anemia or hemoglobinuria. 

Read more about PNH etiology 

Out of a possible 49 cases, the authors of the report found 20 that met their inclusion criteria. A comparison of the cases found that the median age of myeloid neoplasm diagnosis was 65. Of the 20 cases, 10 patients had myelodysplastic syndrome, 9 had myeloproliferative neoplasms, and 1 had acute myeloid leukemia. 

Among the 20 patients, 11 were diagnosed with PNH and myeloid neoplasm concurrently; 5 received a diagnosis of PNH within a year; and 4 were diagnosed with PNH after more than a year, with the median delay being 85 months. 

All 20 patients experienced hemolysis at some stage of their disease; 10 experienced at least 1 thrombotic event. A total of 13 patients received eculizumab treatment and later became transfusion-dependent. The median range of eculizumab treatment was 18 months. A total of 5 patients underwent allogeneic hematopoietic stem cell transplant, 4 of whom were still alive at the end of follow-up. 

“The median overall survival was >7 years, suggesting that [myeloid neoplasms], in our cohort, do not exhibit an aggressive behavior,” the authors of the report wrote. 


Sutra del Galy A, Willems L, D’Aveni M, et al. Haemolytic paroxysmal nocturnal haemoglobinuria in patients with myeloid neoplasms: a rare association with specific therapeutic implications. Br J Haematol. Published online February 17, 2023. doi:10.1111/bjh.18693