Pneumonia in patients with hematological malignancies. Etiology, response to treatment and prognostic factors in 69 patients (88 episodes)

BACKGROUND: TO analyze the etiology, treatment response and prognostic fact ors in 88 episodes of pneumonia in patients with hematological malignancies diagnosed in one center during a period of 30 months. PATIENTS AND METHODS: 88 episodes of pneumonia in 69 adult patients were st udied. Age, sex, hematological malignancy and its treatment, existence of n eutropenia and hypogammaglobulinemia, administration of immunosuppressive a gents, type (hospital or community-acquired) and localization of pneumonia, presence of respiratory failure and treatment response were reported. For etiologic diagnosis of pneumonias, cultures of blood, sputum, pleural fluid and bronchoalveolar lavage (BAL), as well as Legionella pneumophila, Asper gillus fumigatus and Streptococcus pneumoniae antigen detection in urine we re performed. Univariate and multivariate analyses of prognostic factors fo r pneumonia evolution were carried out. RESULTS: The median age was 63 years. Acute leukemias (AL) were the predomi nant hematological malignancies. Microbiologic documentation was obtained i n 40 (45%) of pneumonias. Fiberoptic bronchoscopy with BAL (71%) was the di agnostic procedure with highest yield followed by blood cultures (25%). Str eptococcus pneumoniae (13) was the most frequent isolated pathogen, followe d by Legionella pneumophila (6) and Pseudomonas aeroginosa (6). A significa ntly higher prevalence of Streptococcus pneumoniae was observed in communit y-acquired pneumonia. The overall mortality rate was 20%. Respiratory failu re (p = 0.0009), existence of neutropenia (p = 0.0023), age equal or higher than 60 years (p = 0.012) and prolonged administration of immunosuppressiv e agents (p = 0.015) were the prognostic factors associated with unfavourab le evolution of pneumonias in the multivariate analysis. CONCLUSIONS: The etiologic diagnosis of pneumonia in patients with hematolo gical malignancies was only achieved in a half of cases. In our series, the high prevalence of Legionella pneumophila can be attributed to the special epidemiologic characteristics of our hospital. Prognostic factors of pneum onia are related to individual factors as well as to the hematological stat us of patients.