Managing leukocytosis in malignant pertussis with white blood cell depletion: An effective alternative way to exchange transfusion.

Pertussis is a common infectious disease affecting both children and adults. In young infants, it can cause severe respiratory illness associated with prolonged hospitalization and high mortality, particularly in cases complicated by severe leukocytosis and lymphocytosis, which increase the risk of pulmonary hypertension and multiorgan failure. Exchange transfusion remains the traditional first-line treatment for severe pertussis-associated hyperleukocytosis. However, in centers with appropriate resources and expertise, leukapheresis may be considered as an alternative therapeutic option. Leukapheresis enables selective reduction of circulating white blood cells, which are thought to play a central role in the pathophysiology of severe pertussis, while avoiding exposure to allogeneic blood products. It may also result in incidental platelet removal, potentially reducing blood viscosity and thrombotic risk in patients with concomitant thrombocytosis. Despite these potential advantages, leukapheresis is technically demanding and should be performed only in experienced centers with established protocols and appropriate expertise. Through the apheresis system we treated two patients who developed malignant pertussis with which successfully decreased their WBC counts by more than 50%. In the presence of limited guidance in the current literature regarding its prescription, usage, and safety specifically in pertussis, this report provides additional insights into the prescription and implementation of an effective leukocyte depletion.