The severity of acquired aplastic anemia (AA) and long-term prognosis: lessons from current results of immunosuppressive treatment (IST)
Alexander D. Kulagin1,2, Igor A. Lisukov1,2, Vyacheslav I. Borisov2, Irina V. Kruchkova2, Vera V. Sergeevicheva2, Svetlana A. Sizikova2, Andrey V. Gilevich2, Vladimir S. Kozhevnikov2, Vladimir A. Kozlov2
1Novosibirsk State Medical University, Novosibirsk, Russia; 2Institute of Clinical Immunology SB RAMS, Novosibirsk, Russia (EBMT CIC 375)
Alexander D. Kulagin, Yadrintsevskaya str, 14, 630047, Novosibirsk, Russia
Objectives and Methods
We retrospectively analyzed the outcome of 65 patients (39 M and 26 F, median age 21) with moderate (MAA 22), severe (SAA 26) and very severe (VSAA 17) AA treated with ATG and CsA+/-Daclizumab (44) or with CsA alone (21) from October 1995 to May 2009.
Twenty-two (34%) and 25 (38%) patients achieved CR and PR, respectively (according to strict response criteria of B. Camitta, 2000). The quality of response was higher in the VSAA group (CR/PR=11/1) than in the SAA (9/10, p=0.02) and MAA (2/14, p=0.001) groups.
There were 2 early and 7 late deaths. Four patients (8.5%) relapsed and 3 responded again after re-treatment with ATG and CsA. Late events included MDS/AML (n=2), rectal cancer (n=1) and hemolytic PNH (n=5). The 5-year overall survival was 82 ± 6% without any difference between the MAA (81.6 %), SAA (82.1 %), and VSAA (82.4 %). Surprisingly, there was a marked trend towards better failure-free survival (FFS) in more severe disease (32.6 ± 12.6%, 45.2 ± 11.8% and 68.8 ± 11.7% in MAA, SAA, and VSAA respectively), which was also observed even when the CsA group alone was excluded from analysis.
The results of the telomere length measurement in PB cells by flow-FISH analysis in 35 patients gave a possible explanation for better quality of response and FFS in VSAA. The responders with VSAA have a less marked telomere loss than in MAA and SAA patients, probably due to lack of intrinsic stem cell defects and early intensive IST.
Modern IST provides a high rate of hematological response and long-term survival in more than 80% of AA patients. Nevertheless, different treatment-failure events remain a crucial problem. The severity of AA is a controversial prognostic factor. Our data indicates that more severe AA predicts a better long-term prognosis.
aplastic anemia, severity, ATG, cyclosporine, response, telomere, prognosis