Background
The potential role of elastin in patients with myeloid leukemia treated with hematopoietic stem cell transplantation (HSCT) has not been investigated so far. The objective of the study was to evaluate elastin metabolism before and at two time-points after HSCT.
Material and Method
Forty patients (22 male and 18 female, median age: 34 years, range: 14-54) were included. The diagnoses were acute myeloid leukemia (AML, n=25) and chronic myeloid leukemia (CML, n=15). Busulfan and cyclophosphamide (4+2) were administered as conditioning. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and methotrexate. Twenty-three patients experienced acute GVHD and 17 developed chronic GVHD. Plasma elastase activity (EA) and plasma elastin-derived peptide concentration (EDPc) were measured.
Results
There were statistically significant differences in EA before HSCT (1.3 U/ml) compared with day +30 (2.9 U/ml) and day +100 (3.2 U/ml) after HSCT (p<0.001 for both). EA was also higher in patients with chronic GVHD than in those who did not develop chronic GVHD. EDPc was significantly higher on days +30 (49.3 U/ml) and +100 (57.7 U/ml) after HSCT than on day -10 before HSCT (15.5 U/ml, p<0.001 for both). EDPc was significantly higher in patients with chronic GVHD.
Conclusions
EA and EDPc were increased in patients after HSCT. If the role of elastase in the pathogenesis of GVHD is confirmed, it will be possible to apply inhibitors of elastases in the treatment of this condition in the near future.

Keywords: young adult, Transplantation, Homologous, Peptide Fragments - biosynthesis, Pancreatic Elastase - metabolism, Leukemia, Myeloid - surgery, Elastin - metabolism, Chronic Disease, Adolescent