Pioneering Study about the Presence of Paroxysmal Nocturnal Hemoglobinuria Clone during Therapeutic Monitoring of Acute Leukemia

Abstract

Introduction: The potential for malignant transformation of hematopoietic stem cells carrying mutations in the glycosylphosphatidylinositol class A (PIG-A) gene for acute leukemias, although rare, is already well described in the literature. Objective: In this study, however, it was attempted to show for the first time in the literature the emergence or maintenance of paroxysmal nocturnal hemoglobinuria (PNH) clones in patients diagnosed with acute leukemia or even after the beginning of the chemotherapy treatment. Method: The search of PNH clones was performed by flow cytometry in blasts, erythrocytes, granulocytes or monocytes of 47 samples of peripheral blood and bone marrow from patients undergoing diagnostic investigation or therapeutic follow-up in two oncological and public hospitals in Belém, from December 2017 to December 2018. Results: The presence of PNH clones was observed in 19/47 (40.4%) patient samples, in diagnostic investigation or therapeutic follow-up, who participated of at least one therapeutic follow-up study and still experience the appearance or maintenance of the PNH clone even after the beginning of the chemotherapy treatment. Conclusion: Primarily, it was possible to demonstrate the presence of PNH clones in patients diagnosed with acute leukemia both during the diagnostic investigation period and therapeutic follow-up, regardless of cell ontogeny. However, the importance of the presence of these PNH clones for the evolution of the primary disease, prognosis or need for specific treatment was not evaluated yet.