Background: To analyze the etiology, treatment response and prognostic factors 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 studied. Age, sex, hematological malignancy and its treatment, existence of neutropenia and hypogammaglobulinemia, administration of immunosuppressive agents, 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, Aspergillus fumigatus and Streptococcus pneumoniae antigen detection in urine were performed. Univariate and multivariate analyses of prognostic factors for pneumonia evolution were carried out.
Results: The median age was 63 years. Acute leukemias (AL) were the predominant hematological malignancies. Microbiologic documentation was obtained in 40 (45%) of pneumonias. Fiberoptic bronchoscopy with BAL (71%) was the diagnostic procedure with highest yield followed by blood cultures (25%). Streptococcus pneumoniae (13) was the most frequent isolated pathogen, followed by Legionella pneumophila (6) and Pseudomonas aeruginosa (6). A significantly higher prevalence of Streptococcus pneumoniae was observed in community-acquired pneumonia. The overall mortality rate was 20%. Respiratory failure (p = 0.0009), existence of neutropenia (p = 0.0023), age equal or higher than 60 years (p = 0.012) and prolonged administration of immunosuppressive agents (p = 0.015) were the prognostic factors associated with unfavourable evolution of pneumonias in the multivariate analysis.
Conclusions: The etiologic diagnosis of pneumonia in patients with hematological 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 pneumonia are related to individual factors as well as to the hematological status of patients.