OBJECTIVETo elucidate the clinical features, response rate, prognosis and clonal evolution of aplastic anemia (AA) with macrocytic anemia (mAA).

METHODSThe clinical features at initial diagnosis and data in follow up of mAA hospitalized from January 2000 to October 2011 were analyzed retrospectively.

RESULTS(1) Of 153/568 (26.9%) cases of mAA at initial diagnosis, 114(74.5%)were non-severe AA (NSAA), 39(25.5%)severe AA (SAA) and 0 very severe AA (VSAA), while the proportion was 16.2%, 45.2%, and 38.6% in 376 normocytic anemia AA (nAA), and the difference is statistically significant(χ(2) = 181.390; P = 0.000). The median age of mAA was significantly higher than that of nAA \[30(4 - 70)years vs 19 (3 - 68) years, P = 0.001\]. (2) There were no statistical difference in hemoglobin, absolute neutrophil count (ANC), platelet count (PLT), response rate after 6 months treatment and overall survival (OS) between mAA and nAA grouped in SAA and NSAA respectively. In SAA, the reticulocyte count (Ret) of mAA was significantly higher than that of nAA \[23.90(2.99 - 61.00)×10(9)/L vs 13.1(0 - 70.60)×10(9)/L, P = 0.000\] and the proportion of erythroid cells in bone marrow of mAA was also higher \[23.5 (0 - 58) vs 14.5 (0 - 65), P = 0.043\], while they did not differ significantly in NSAA. (3) The proportion of AA with PNH clones or abnormal cytogenetics did not differ significantly in mAA and nAA groups before treatment. The incidences of AA evolved to PNH in mAA and nAA was not statistically significant (7/153 vs 9/376, χ(2) = 1.099, P = 0.294) and so was the incidence of evolution to MDS/AML(3/153 vs 13/376, χ(2) = 0.399, P = 0.528).

CONCLUSIONIn presented with macrocytic anemia at initial diagnosis of AA, higher proportion of NSAA, elderly age, higher Ret and proportion of erythroid cells are features, but being no statistical difference in the response rate, OS, and proportion of clonal evolution.