Dendritic cells in bone marrow at diagnosis and after chemotherapy in adult patients with acute myeloid leukaemia.

Dendritic cells (DCs) develop in the bone marrow from haematopoietic progenitor cells. Two subsets, plasmacytoid DCs (pDCs) and myeloid DCs (mDCs), have been identified. Little is known regarding DC levels in bone marrow of patients with acute myeloid leukaemia (AML) before and after chemotherapy. We investigated relative pDC and mDC levels in bone marrow from 37 hospital controls and 60 patients with AML [at diagnosis, complete remission (CR) and follow-up] using four-colour flow cytometry. The pDC immunophenotype was characterized as lin-/HLA-DR+/CD123 +  and mDC as lin-/HLA-DR+/CD11c+. In 69% of patients with AML, no DCs were detected at diagnosis. At CR, mDC levels were the same in patients with AML and hospital controls while pDC levels were slightly lower. There was no association between minimal residual disease or survival rates and DC levels. Patients with low mDC levels at CR were more likely to suffer from complicated infections, although the difference was not statistically significant. Altogether, there was a profound decrease in DC levels in patients with AML at diagnosis. DC levels increased at CR and were higher than in hospital controls after post-remission therapy, suggesting that DCs recover after repeated chemotherapy. There may be an association between mDC levels and infectious complications.

Continued improvement in survival of acute myeloid leukemia patients: an application of the loss in expectation of life.

We evaluated temporal trends in survival of Swedish acute myeloid leukemia (AML) patients diagnosed between 1973 and 2011 using relative survival ratios (RSRs) and a measure called the loss in expectation of life (LEL). RSRs increased most for patients <60 years at diagnosis during the first calendar periods, but between 1997-2005 and 2006-2011 the most pronounced increase was for those aged 61-70 years at diagnosis; RSR changed from 0.16 (95% confidence interval (CI): 0.13-0.19) to 0.28 (95% CI: 0.23-0.33), respectively. The LEL for males aged 35 years at diagnosis was 41.0 (95% CI: 40.1-41.8) years in 1975 and 19.5 (95% CI: 16.4-22.5) years in 2011. For males aged 65 years, the corresponding figures were 13.8 (95% CI: 13.7-14.0) and 12.0 (95% CI: 11.3-12.8). Conditional LEL estimates suggested that patients who survive 5 years postdiagnosis have shorter remaining lifespan than the general population. The proportion of expected life lost (PELL) suggested that male 65-year-old patients lost 75% of their life expectancy in 2005 and 66% if they were diagnosed in 2011. Survival continued to increase to 2011, with larger improvements in those aged 61-70 years at diagnosis. The LEL and PELL are intuitive measures that may be useful in communicating survival statistics to patients, clinicians and health-care providers.