Influence of Prophylactic Platelet Transfusions on the Recovery of Bone Marrow Function After Intensive Chemotherapy for Acute Myeloid Leukemia.
Authors: Kivit Roland MH , Joosten Peter , Hoogendoorn Mels , De Wolf Joost TM 
Published: October 2019

Abstract
Abstract 1118

Introduction:
Treatment of acute myeloid leukemia (AML) patients (< 65 years) consists of intensive chemotherapy. During the aplastic period after chemotherapy it is common to support the patient with prophylactic platelet transfusions (PT) in order to keep platelet count above 10 × 109/L. However, by some it is questioned if the prophylactic transfusion is necessary and whether a therapeutic platelet transfusion (TT) policy might be sufficient. We studied the effects of the two transfusion policies on number of platelet transfusions, bleeding complications, duration of thrombocytopenia and days of hospital stay in two departments of hematology: one in a large tertiary care hospital (MCL;TT) and the other in an university hospital (UMCG; PT). In both hospitals the same chemotherapy was used for the treatment of AML patients. The first chemotherapy course consists of Ara-C (200 mg/m2/ci, days 1–7) and Idarubicin (12 mg/m2/i.v., days 5,6,7); the second course consists of Ara-C (1000 mg/m2, 3 hrs inf, q 12 hrs × 12, days 1–6) and Amsa (120 mg/m2/i.v. days 3,5,7); some patients received a third course consisting of Mitoxantrone (10 mg/m2/i.v. × 5, days 1–5) and Etoposide (100 mg/m2/i.v. × 5, days 1–5). With PT platelets were transfused if the morning platelet count dropped below 10 × 109/L; in case of TT platelets were transfused when new petechiae developed, clinically relevant bleeding occurred or gastro-intestinal bleeding is suspected.

Results:
26 patients were treated with 54 chemotherapy courses and received PT; 15 patients, 34 chemotherapy courses received TT. Age was similar in both groups: 50 ± 11 resp 50 ± 12 years. There was no significant difference in the number of different chemotherapy courses between the two groups. 48% of the chemotherapy courses in the PT group consisted of Ara-C/Idarubicin, 44% Ara-C/Amsa en 8% Mitoxantrone /Etoposide, compared to 41% (p=0.7), 38% (p=0.7) and 21% (p=0.1) in the TT group. In the PT group 8,5 ± 5,1 platelet transfusions were used per chemotherapy course compared to 4,2 ± 2,5 in the TT group (p < 0.0001). Bleeding complications occurred significantly more in the TT group. In the TT group 11 bleeding complications were observed in 34 chemotherapy courses: 6 gastro-intestinal bleedings, inconvenient vaginal bleeding in 2 chemotherapy courses, 1 hematuria,1 significant subcutaneous bleeding and 1 cerebral hemorrhage; in the PT group 7 bleeding complications occurred in 54 courses (p=0.03): 5 chemotherapy courses were complicated by vaginal bleedings, 1 retinal bleeding and 1 gastro-intestinal bleeding. Especially gastro-intestinal bleedings occurred significantly more in the TT group: 6/34 courses vs 1/54 courses (p=0.01) in the PT group. Recovery of bone marrow function (absolute neutrophil count > 0.5 × 109/L; platelet count > 20 × 109/L, without platelet transfusions) was reached earlier in the TT group. Absolute neutrophil count > 0.5 × 109/L was noticed 26 ± 12 days after start of chemotherapy in the TT group compared to 32 ± 7 days after start chemotherapy in the PT group (p=0.01). Platelet count > 20 × 109/L without platelet transfusions was seen 21 ± 11 days after start chemotherapy in the TT group compared to 32 ± 13 days in the PT group (p<0.0001). Days in hospital was significantly reduced in the TT group: 29 ± 8 days compared to 38 ± 15 in the PT group (p=0.002). In summary, these data demonstrate that a therapeutic platelet transfusion strategy might lead to a reduced number of platelet transfusions, faster recovery of bone marrow function after chemotherapy and reduced hospital stay. Although manageable, more gastro-intestinal bleedings occurred in this group of patients.

Disclosures:
No relevant conflicts of interest to declare.