Background: The correct management of immunocompromised patients with pneumonia is debated. We evaluated the prevalence, risk factors, and characteristics of immunocompromised patients coming from the community with pneumonia. Methods: We conducted a secondary analysis of an international, multicenter study enrolling adult patients coming from the community with pneumonia and hospitalized in 222 hospitals in 54 countries worldwide. Risk factors for immunocompromise included AIDS, aplastic anemia, asplenia, hematological cancer, chemotherapy, neutropenia, biological drug use, lung transplantation, chronic steroid use, and solid tumor. Results: At least 1 risk factor for immunocompromise was recorded in 18% of the 3702 patients enrolled. The prevalences of risk factors significantly differed across continents and countries, with chronic steroid use (45%), hematological cancer (25%), and chemotherapy (22%) the most common. Among immunocompromised patients, community-acquired pneumonia (CAP) pathogens were the most frequently identified, and prevalences did not differ from those in immunocompetent patients. Risk factors for immunocompromise were independently associated with neither Pseudomonas aeruginosa nor non–community-acquired bacteria. Specific risk factors were independently associated with fungal infections (odds ratio for AIDS and hematological cancer, 15.10 and 4.65, respectively; both P = .001), mycobacterial infections (AIDS; P = .006), and viral infections other than influenza (hematological cancer, 5.49; P < .001). Conclusions: Our findings could be considered by clinicians in prescribing empiric antibiotic therapy for CAP in immunocompromised patients. Patients with AIDS and hematological cancer admitted with CAP may have higher prevalences of fungi, mycobacteria, and noninfluenza viruses.

We developed a novel mouse model of malignant pleural effusion (MPE) by injecting Lewis lung cancer (LLC) cells directly into the pleural space of syngeneic C57B/6 mice. The pleural effusions in this model share common cellular and biochemical features with human MPEs. Implantation and growth of pleural tumors triggers a host inflammatory response characterized by a mixed inflammatory cell influx into the pleural fluid. LLC cells exhibited high basal nuclear factor (NF)-κB activity in vitro and in vivo, which we used to drive expression of a NF-κB–dependent green fluorescent protein-firefly luciferase fusion reporter construct. NF-κB–dependent reporter expression allowed intravital tracing of pleural tumors. Inhibition of NF-κB in LLC cells did not affect cell viability in culture; however, injection of LLC cells expressing a dominant NF-κB inhibitor resulted in decreased tumor burden, decreased pleural effusion volume, and decreased pleural effusion TNF-α levels. These studies indicate that tumor NF-κB activity regulates pleural tumor progression. This reproducible model of MPE can be used to further study the influence of specific host and tumor factors on the pathogenesis of MPE and evaluate new therapeutic strategies.

CT bronchus sign (BS) designates a bronchus leading directly to a peripheral pulmonary lesion. The objective of this investigation is to determine the contribution of BS-guided bronchoscopic multiple diagnostic procedures (BMDPs) to the diagnostic yield of solitary nodules or masses (SPNMs) suspected of pulmonary carcinoma (PC). A prospective study was carried out in 92 patients with a 2–5 cm diameter SPNM at the level of third to fifth bronchial branching and without endobronchial tumors. Within 10 days after 2-mm CT scans were done, in each of 92, bronchial washing (BW), brushing (BR), transbronchial needle aspiration (TBNA) and transbronchial lung biopsy (TBB) were performed respectively, via fiberoptic bronchoscopy (FB) under fluoroscopic guidance. In 40 (82%) of 49 with BS and in 19 (44%) of 43 without BS, FB established the diagnosis (p < 0.01). In 84 cases of PC, BW, BR, TBNA and TBB provided the diagnostic yields of 4% (3), 26% (22), 57% (48) and 49% (41), respectively; the combined yield reached 68% (57). A metastasis and a tuberculoma were diagnosed exclusively by TBB, and TBNA, respectively. All differences of diagnostic yield except that between TBNA and TBB (p > 0.05) were determined to be significant (p < 0.05). Thoracotomy verified diagnosis in 48 of 59 cases diagnosed and 19 of 33 undiagnosed by FB, and various tissue biopsies or clinical follow-up in 11 diagnosed and 14 undiagnosed by FB. The above data suggest that in the diagnosis of PC as a SPNM at the level of third–fifth bronchial branching, combining the guidance of CT BS, and BMDPs under fluoroscopic guidance can increase the yield considerably.