An Incredible Impact of Antibiotics on Leukostasis.

Leukostasis is characterized by respiratory or neurological issues in the context of hyperleukocytosis, secondary to elevated blood viscosity and WBC plugs (aggregates of mature leukocytes or leukemic blasts physically obstructing the microvasculature leading to impaired tissue perfusion and organ dysfunction). It is rare in Chronic Lymphocytic Leukemia (CLL) unless WBC >500,000/μL. A 67-year-old female presented with severe respiratory distress and altered mental status. She was diagnosed with Streptococcus pneumoniae meningitis and pneumonia. Laboratory diagnostics demonstrated hyperleukocytosis (WBC >440,000/μL) and CLL confirmed by flow cytometry. Imaging showed bilateral acute brain infarcts. After 12 days of antibiotic therapy, her WBC dropped to 40,000/μL, her condition improved, and she was discharged for CLL follow-up. This case illustrates that in cases of CLL complicated by hyperleukocytosis, evaluation and treatment of a superimposed infection may persistently improve hyperleukocytosis and leukostasis.