(P-TA-8) Laboratory Changes Following Therapeutic Leukapheresis: A Retrospective Analysis of 154 Procedures

Background/Case Studies: Therapeutic leukapheresis is a well-established procedure to rapidly reduce leukocyte counts in patients with hyperleukocytosis, particularly those with hematologic malignancies. Despite its widespread use, detailed data regarding laboratory changes associated with the procedure remain limited.

Study

Design/Methods: We retrospectively reviewed 154 therapeutic leukapheresis procedures performed from March 1st, 2024 to April 30th, 2025, at Ewha Womans University Mokdong Hospital, Seoul, Republic of Korea. Among these, 153 procedures with available pre- and post-WBC data were included in the final analysis. Patient demographics and laboratory parameters - including white blood cell (WBC) counts, serum potassium (mmol/L), phosphorus (P), and ionized calcium (Ca) levels - were collected before and after each procedure. Prophylactic calcium infusion was routinely administered to prevent hypocalcemia during the procedure. Laboratory changes were assessed using the Wilcoxon signed-rank test.

Results/Findings: A total of 33 patients, including those diagnosed with AML, CML, and other hematologic malignancies, underwent therapeutic leukapheresis, with a median age of 62 years (range: 31–77). The median number of procedures per patient was 4 (range: 1–9).
The changes in laboratory parameters are summarized in Table 1. Among the 153 procedures analyzed, the mean WBC count significantly decreased from 143.29 ×10³/µL to 112.90 ×10³/µL (p < 0.0001). Hemoglobin and platelet counts showed no significant differences before and after the procedures, indicating hematologic stability during treatment. In addition to the reduction in WBC, serum ionized calcium levels significantly increased from 4.36 mg/dL to 4.69 mg/dL (p < 0.0001), while serum phosphorus levels significantly decreased from 3.67 mg/dL to 3.42 mg/dL (p < 0.0001). Serum potassium (mmol/L) levels remained stable (p = 0.3472). No major adverse events related to the procedure were reported.

Conclusions: Therapeutic leukapheresis effectively reduces leukocyte burden and induces significant changes in calcium and phosphate levels. Routine prophylactic calcium infusion likely contributed to the prevention of hypocalcemia, a common complication of therapeutic leukapheresis. These findings underscore the importance of vigilant electrolyte monitoring and supportive care during and after the procedure. Further prospective studies are warranted to validate these results and guide optimal patient management strategies.