Effect of leukapheresis on blood coagulation in patients with hyperleukocytic acute myeloid leukemia

Leukapheresis has been proposed to reduce white blood cell (WBC) count in hyperleukocytic acute myeloid leukemia (AML). However, no survival benefit has been proven and leukapheresis can potentially affect coagulation and worsen bleeding and disseminated intravascular coagulation (DIC). We analyzed the effect of leukapheresis on coagulation tests in a cohort of hyperleukocytic AML patients.

Retrospective chart review of hyperleukocytic AML patients who underwent leukapheresis between 2003 and 2014. Blood coagulation tests (platelets, PT, INR, aPTT, fibrinogen, D-Dimers and fibrin degradation products (FDP)) were collected before and after each procedure and DIC score was computed. Transfusions of platelets and coagulation factors were collected.

Ninety patients and 129 leukapheresis sessions were screened. After exclusion of the sessions associated with transfusions, we observed in 44 patients a significant decrease in platelets (from 75.69±89.48 to 44.59±47.71.10⁹/L, p=0.001) and fibrinogen (from 4.05±1.29 to 3.35±1.37g/L, p<0.0005) along with an increase in PT (from 14.62±2.73 to 15.62±3.63s, p=0.001), aPTT (from 33.70±6.32 to 39.24±13.53s, p=0.009) and INR (from 1.33±0.2 to 1.45±0.34, p=0.002) after the first procedure. Bleeding complications, all intracerebral hemorrhages, were documented in 3 patients within 24h of leukapheresis. After combining 73 repeat procedures, we observed similar significant results except for the aPTT prolongation. The platelets and PT components of the DIC score, but not the fibrinogen component, were significantly increased after leukapheresis.

In hyperleukocytic AML patients, leukapheresis is associated with clinically significant decreases in platelets and fibrinogen and prolonged clotting times.