OBJECTIVETo analyze the clinical characteristics and risk factors on responses and survival of myelodysplastic syndromes (MDS) patients with paroxysmal nocturnal hemoglobinuria (PNH) clones.

METHODSThe clinical data of 31 MDS cases with PNH clones from October 2004 to June 2012 were retrospectively analyzed to reveal the influence of PNH clone size on responses and survival.

RESULTS①The chromosome karyotypes were analyzed in all patients, 23 patients with normal karyotype, 7 patients with abnormal karyotype [including 3 patients with +8, 2 -Y, 1 del(7q) and 1 Xp+] and 1 patient with no mitosis. 1 patient belonged to low-risk, 27 intermediate-1 risk, 2 intermediate-2 risk and 1 high-risk groups, respectively, according to IPSS. There were significantly statistical differences between responders and nonresponders in terms of infection, ANC, Reticulocyte count and IPSS (P values were 0.049, 0.006, 0.031 and 0.043, respectively). ②The overall responsive rate was 67.7%, no patients progressed to acute leukemia (AL) during median follow-up of 19 months after immunosuppressive therapy (IST). The 3-year and 5-year overall survival rates were 82.7% and 55.1%,respectively. ③According to univariate analysis,age, infection and ANC had significant influence on survival (P values were 0.050, 0.031 and 0.026, respectively). ④The PNH clone size had no significant influence on survival through univariate and COX analyses (P=0.393).

CONCLUSIONMDS patients with PNH clone had less cytogenetic abnormalities, higher probability of response to IST and lower probability of progression to AL; Furthermore, the PNH clone size had no significant influence on response and survival.