5. Conclusion
As a traditional treatment for PNH, corticosteroids are still the first-line drug for PNH patients in China. However, how to treat refractory/relapsed PNH for patients in whom corticosteroids are ineffective or who are dependent on corticosteroids has always been a difficult problem for clinicians. For patients with refractory/relapsed PNH, low-dose combined chemotherapy is an effective choice, which can reduce the number of PNH clones and allow normal clones to expand to promote normal hematopoiesis and control hemolytic attack. This is a promising and widely used therapeutic method at present.