Comparative studies on localized leukocyte mobilization in patients with chronic myelocytic leukemia

Using autologous serum as medium, localized leukocyte mobilization into a plastic chamber at the site of mechanical abrasion was quantified in 5 patients with florid CML, one patient with chronic eosinophilic leukemia in the florid state, 3 patients (5 studies) with CML and partial response (remission or relapse), 6 patients with CML in good remission, and in 7 patients with CML in die blastic phase. The cumulative total number of cells was expressed as total leukocyte mobilization (TLM) × 10⁶/cm² at 24 hrs. Leukocyte clearance/cm² in 24 hrs. was expressed in milliliters of blood and was obtained by dividing TLM (corrected for non‐granulocytes) by the absolute granulocyte count in the peripheral blood. Although the median TLM was found to be elevated in CML with florid disease (130 × 10⁶/cm² at 24 hrs.) and in CML with partial remission and relapse (104 × 10⁶), it fell to 74 × 10⁶ in 6 patients in remission. This is to be compared with the median TLM for 46 normal subjects (76 × 10⁶/cm² at 24 hrs.). Median leukocyte clearances showed the lowest values in CML in the florid state (1.0 ml/cm² in 24 hrs), improving to 4.4 ml when a partial response was present, and to 9.3 ml in remission. This compares with 19.7 ml/cm² in 24 hours for 46 normal subjects. The median TLM in 7 patients with CML in blastic phase was 14 × 10⁶/cm² at 24 hrs., and the leukocyte clearance was reduced to 1.4 ml. These data suggest a defect in cell‐migration in all stages of CML, which is inversely correlated with clinical state. The data reinforce the reported prolongation of circulation time of leukocytes in CML, and suggest a mechanism for this in the impaired ability of CML leukocytes to migrate across the vessel wall.