Annals of hematology

The role of paroxysmal nocturnal hemoglobinuria clones in response to immunosuppressive therapy of patients with severe aplastic anemia.

PMID 25784221


Whether paroxysmal nocturnal hemoglobinuria (PNH) clone in aplastic anemia (AA) is a prognostic factor to immunosuppressive therapy is a subject of debate. We evaluated hematological responses to immunosuppressive therapy (IST) in severe AA (SAA) patients with or without the presence of a PNH clone. In 97 SAA patients who received first-line IST between January and December 2011, 24 (24.7xa0%) had a PNH clone prior to treatment, with a median clone size of 7.82xa0% (range 1.19-45.46xa0%). The response rates to IST for patients with or without a PNH clone were 66.7 and 50.7xa0% (P < 0.172), 79.2 and 57.5xa0% (P < 0.057), and 79.2 and 67.1xa0% (P < 0.264) at 3, 6, and 12xa0months, respectively. Combined rate of complete and good partial responses differed between patients with or without a PNH clone: insignificantly at 3xa0months (41.7 vs. 21.9xa0%, P < 0.058), but significantly at 6 (66.7 vs. 31.5xa0%, P < 0.002) and 12 (75.0 vs. 46.6xa0%, P < 0.015) months. Multivariate analysis revealed that a pretreatment neutrophil count of >0.2 × 10(9)/L is indicative of a better response, while the presence of a PNH clone is predictive to a higher combined rate of complete and good partial responses. This study demonstrated that the presence of a PNH clone could predict a better hematological response instead of a higher response rate in patients with SAA.