Patients with
myelodysplastic syndrome (MDS) often require
blood transfusion and anticancer
therapy; however, elderly patients are intolerant to the associated side effects of anticancer
therapy. Because
L-leucine can be used to treat
Diamond-Blackfan anemia, which is caused by defects in
ribosomal protein (RP) genes, resulting in increased in vivo
hemoglobin synthesis, it is possible that some MDS patients who have aberrations in their RP genes could also be effectively treated with
L-leucine. In the present study, we investigated the effects of
L-leucine on hematopoietic function (reticulocyte count), red blood cell count, and
hemoglobin level in MDS patients. We administered
L-leucine (1.8 g, twice daily, 3 d/week) with oral
vitamin B6 supplements to a final cohort of eight MDS patients for 15 (interquartile range: 11-18) weeks. We assessed the patients at 10 ± 2 weeks after
therapy initiation. Only the absolute reticulocyte count was affected, improving in 6/8 (75%) patients. The median absolute reticulocyte count was 3.5 × 104 (range: 2.7-6.4 × 104) cells/µL, an increase of 0.5 × 104 (range: 0.2-0.7 × 104) cells/µL.
At 10 weeks, there was only one case of an improved
hemoglobin level. Non-hematological adverse events of grade 3 were observed one raised
triglycerides. These data suggest that
L-leucine has little effect on MDS. However, it may contribute to the recovery of hematopoietic function, futher study be desired.