Hyperleukocytosis and leukocytapheresis in acute leukaemias: experience from a single centre and review of the literature of leukocytapheresis in acute myeloid leukaemia.

BACKGROUND: Hyperleukocytosis is usually defined as leukocyte count >100 × 10(9) L(-1) and can be seen in newly diagnosed leukaemias. Hyperleukocytic leukaemia is associated with a risk of organ failure and early death secondary to leukostasis. Mechanical removal of leukocytes by the apheresis technique, leukocytapheresis, is a therapeutic option in these patients. METHODS: During a 16-year period, 16 patients were treated with leukocytapheresis (35 apheresis procedures) for hyperleukocytosis/leukostasis. We present our experience, and in addition we review previous studies of hyperleukocytosis/leukocytapheresis in patients with acute myeloid leukaemia (AML). RESULTS: We used a highly standardised approach for leukocytapheresis in leukaemia patients with hyperleukocytosis. The average leukocytapheresis number for each patient was 2·2 (range 1-6). Median leukocyte count before apheresis was 309 × 10(9) L(-1) (range 104-935); the mean leukocyte count reduction was 71%, corresponding to a mean absolute reduction of 219 × 10(9) L(-1). No serious side effects were seen during or immediately after apheresis. CONCLUSIONS: The data suggest that our standardised technique for leukocytapheresis effectively reduced the peripheral blood leukaemia cell counts. Previous studies in AML also support the conclusion that this is a safe and effective procedure for the treatment of a potentially life-threatening complication, but apheresis should always be combined with early chemotherapy.

Large-volume leukapheresis yields more viable CD34+ cells and colony-forming units than normal-volume leukapheresis, especially in patients who mobilize low numbers of CD34+ cells.

BACKGROUND: Large-volume leukapheresis (LVL) differs from normal-volume leukapheresis (NVL) by increased blood flow and altered anticoagulation regimen. LVL is now regarded as a safe procedure for collection of peripheral blood progenitor cells (PBPCs), but it is not known whether the procedure will alter CD34+ cell quality or will be useful for patients who mobilize few CD34+ cells into peripheral blood. STUDY DESIGN AND METHODS: The results from 82 LVL and 125 NVL (4.0-5.3 and 2.7-3.5 times the patients' blood volumes processed, respectively) were retrospectively analyzed in altogether 112 consecutive patients with malignant diseases. RESULTS: The LVL yielded significantly more CD34+ cells (4.2 x 10(6) vs. 3.1 x 10(6)/kg, p = 0.006, all patients; and 1.8 x 10(6) vs. 1.3 x 10(6)/kg, p = 0.004, bad mobilizers) and significantly higher colony-forming units (77 x 10(4) vs. 33 x 10(4)/kg; all patients and 33 x 10(4) vs. 20 x 10(4)/kg, p < 0.001, both groups). Significantly fewer leukapheresis procedures were required to obtain 2 x 10(6) CD34+ cells per kg (one vs. two, p = 0.001, all patients; and two vs. three, p = 0.009, bad mobilizers). No significant differences in CD34+ cell viability and time to hematologic recovery were observed between the patients who received PBPCs harvested by NVL and LVL. CONCLUSION: Although a median platelet loss of 36 percent can be expected, LVL can be recommended as the standard apheresis method for PBPC collections in patients with malignant diseases. LVL is particularly useful in patients who mobilize a low number of CD34+ cells into the peripheral blood.