Clinical characteristics of 512 eculizumab-naive paroxysmal nocturnal hemoglobinuria patients in China: a single-center observational study

Objectives With large patient population and complement inhibitors naïve background, the characteristics patients with paroxysmal nocturnal hemoglobinuria (PNH) in China have not been well studied, especially for different subtypes.Methods We retrospectively reviewed patients with complete data who visited Peking Union Medical College Hospital (PUMCH) from 2009 to 2019 and had been followed up for more than 2 years.Results Five hundred and twelve patients were enrolled including 56.3% males and 43.7% females. The median age at disease onset was 33 (9∼80) years. Most were aged 21∼40 years (50.6%). 52.1%, 46.3% and 1.6% of the patients had classic PNH, bone marrow failure (BMF)/PNH and subclinical PNH, respectively. Symptoms of classic PNH were associated with hemolysis, whereas bleeding was more common in BMF/PNH patients. Classic PNH had higher survival rate, larger PNH clone size, higher lactate dehydrogenase (LDH) level and lower ferritin level than BMF/PNH. Although the rate of thrombosis was similar in the classic PNH and BMF/PNH (P = 0.66), those with BMF/PNH had higher chance of renal impairment (P < 0.05). Immunosuppressive agents was more common use in BMF/PNH (P < 0.05), but glucocorticoids, iron supplements and anticoagulants were more common used in classic PNH (P < 0.05) patients. Less evolution to myeloid malignancies was observed in classic PNH than in BMF/PNH (P = 0.02). The major causes of deaths were thrombosis (29.6%), hemorrhage (18.5%) and infections (18.5%).Conclusion Patients with classic PNH and BMF/PNH have different clinical profiles, and we described a more hemolytic features of PNH in China which might be improved with complement inhibitors.