Pulmonary complications

Abstract

Up to 25 % of patients with profound neutropenia lasting for >10 days develop lung infiltrates, which are frequently refractory to broad-spectrum antibacterial therapy. While a causative pathogen remains undetected in the majority of cases, Aspergillusspp., Pneumocystis jirovecii, multiresistant gram-negative pathogens, mycobacteria, or respiratory viruses frequently are involved. In patients who have received trimethoprim-sulfamethoxazole prophylaxis, filamentous fungal pathogens appear to be predominant, yet commonly not microbiologically proven at the time of treatment initiation. Preemptive treatment with mold-active systemic antifungal agents such as voriconazole and liposomal amphotericin B improves clinical outcome, while other microorganisms are preferably treated only when microbiologically documented. Pathogens isolated from blood cultures, bronchoalveolar lavage, or respiratory secretions are not necessarily relevant for the etiology of pulmonary infiltrates and should therefore be interpreted with caution. Laboratory tests for detecting circulating fungal antigens such asAspergillusgalactomannan assay, beta-D-glucan or fungal DNA testing from blood, bronchoalveolar lavage, or tissue specimen testing may facilitate the diagnosis; however, PCR techniques are not yet standardized and validated. High-dose trimethoprim-sulfamethoxazole is the first choice for the treatment ofPneumocystispneumonia, while cytomegalovirus pneumonia is treated primarily with ganciclovir in most patients.