Study objectives: Pneumonia during chemotherapy-induced leukocytopenia is a major cause of overall treatment failure in patients with hematologic malignancies. To improve outcome in these high-risk patients, early diagnosis of pulmonary infiltrates and institution of adequate antimicrobial treatment are mandatory. To identify patients with evolving pneumonia, we have prospectively studied the prognostic value of cytokine and complement measurements in early BAL samples from febrile leukocytopenic patients.
Design: Prospective, comparative study.
Setting: Hematology/oncology section of a university hospital.
Patients: Twenty-one patients with leukocytopenia (WBC count <1.000/µL) following cytoreductive chemotherapy for malignant disorders.
Intervention: Early BAL sampling primarily for microbiologic diagnostic purposes.
Measurements and results: Proinflammatory cytokines and activated complement components were measured in the BAL aspirates and the results were related to the prevalence or subsequent evolution of overt pneumonia. Of the 21 patients studied, 10 patients presented with overt pneumonia at BAL sampling (group A), 5 patients developed objective signs of pneumonia 3 to 5 days after BAL (group B), and 6 patients remained free of pneumonia during follow-up (group C). In comparison with group C, patients in groups A and B both had distinctly elevated bronchoalveolar levels of tumor necrosis factor-α, interleukin-6, granulocyte colony-stimulating factor, C3a, and C5a.
Conclusions: Cytokine and complement determinations in early BAL samples may aid in the identification of febrile leukocytopenic patients with evolving pneumonia 3 to 5 days prior to the manifestation of diagnostic clinical and radiographic signs.