Kim BK, et al. Allergy Asthma Immunol Res. 2020 Nov;12(6):910-933. https://doi.org/10.4168/aair.2020.12.6.910

Bacterial pneumonia occurring after respiratory viral infection is common. However, the predominant bacterial species causing pneumonia secondary to respiratory viral infections other than influenza remain unknown. The purpose of this study was to know whether the pathogens causing post-viral bacterial pneumonia vary according to the type of respiratory virus. Study subjects were 5,298 patients, who underwent multiplex real-time polymerase chain reaction for simultaneous detection of respiratory viruses, among who visited the emergency department or outpatient clinic with respiratory symptoms at Ulsan University Hospital between April 2013 and March 2016. The patients' medical records were retrospectively reviewed. A total of 251 clinically significant bacteria were identified in 233 patients with post-viral bacterial pneumonia. Mycoplasma pneumoniae was the most frequent bacterium in patients aged <16 years, regardless of the preceding virus type (p=0.630). In patients aged ≥16 years, the isolated bacteria varied according to the preceding virus type. The major results were as follows (p<0.001): pneumonia in patients with influenza virus (type A/B), rhinovirus, and human metapneumovirus infections was caused by similar bacteria, and the findings indicated that Staphylococcus aureus pneumonia was very common in these patients. In contrast, coronavirus, parainfluenza virus, and respiratory syncytial virus infections were associated with pneumonia caused by gram-negative bacteria. The pathogens causing post-viral bacterial pneumonia vary according to the type of preceding respiratory virus. This information could help in selecting empirical antibiotics in patients with post-viral pneumonia.

Background: Active tuberculosis (TB) develops in approximately 10% of people with a latent tuberculosis infection (LTBI). TB guidelines recommend that LTBI screening and treatments target high-risk patients. Malignancies are not universally considered a high-risk factor for active TB. This study aimed to determine the degrees to which active TB risk was associated with various cancers in a Korean population. Methods: This study involved patients aged ≥20 years who were diagnosed with cancer at Ulsan University Hospital (UUH) from January 2000 to December 2014 and individuals who visited UUH for health screening and were age- and sex-matched randomly with cases in a 1:2 ratio. Using retrospective cohort study, the development of bacteriologically confirmed TB (BCTB) within 3 years after enrollment was investigated. The relative risks of BCTB were estimated using incidence rate ratios (IRRs) and a Poisson regression analysis. Results: During the study period, 380 of 34,783 cancer patients and 79 of 69,566 control subjects developed BCTB, yielding respective incidence rates of 535 and 37/100,000 person-years, respectively. In all cancer cases, the IRR of BCTB was 14.30, and especially high rates were associated with the following cancers: esophageal cancer (74.72), multiple myeloma (70.76), lung cancer (50.35), pancreatic cancer (46.04), leukemia (40.45), head and neck cancer (24.60), and lymphoma (22.67). Conclusions: The incidence of active TB was higher in cancer patients than in control subjects. In particular, lung cancer, esophageal cancer, pancreatic cancer, hematologic malignancy and head and neck cancer were identified as high-risk factors for active TB, as indicated by IRRs of 20-75. These findings suggest that patients with high-risk cancers should be targeted for LTBI screening and treatment.

Central airway obstruction (CAO) can be attributed to several benign or malignant conditions. Although surgery is the preferred therapeutic option for the management of CAO, bronchoscopic treatment can be performed in scenarios where the surgical procedure is not possible. Recent years have witnessed several improvements in the field of bronchoscopic treatment, especially with regard to airway stents. Current research involves new attempts to overcome the existing shortcomings pertaining to the stents (migration, mucostasis, and granulation tissue formation). The authors have recently developed a new silicone airway stent (GINA stent) with an anti-migration design, dynamic structure that enables the reduction of stent cross-sectional area, and radio-opacity. The present study aimed to evaluate the mechanical characteristics and performance of the novel GINA stent using a porcine tracheal stenosis model. In the current study, all the tests involved the comparison of the GINA stent [outer diameter (OD, mm): 14; length (L, mm): 55] with the Dumon stent (OD: 14; L: 50). The mechanical tests were performed using a digital force gauge, in order to determine the anti-migration force, expansion force, and flexibility. The present study evaluated the short-term (3 weeks) performance of the two stents after implantation [GINA (n = 4) vs. Dumon (n = 3)] in the porcine tracheal stenosis model. The results pertaining to the comparison of the mechanical properties of the GINA and Dumon stents are stated as follows: anti-migration force (18.4 vs. 12.8 N, P = 0.008); expansion force (11.9 vs. 14.5 N, P = 0.008); and flexibility (3.1 vs. 4.5 N, P = 0.008). The results pertaining to the comparison of the short-term performance of the GINA and Dumon stents are stated as follows: mucus retention (0/4 vs. 0/3); granulation tissue formation (0/4 vs. 0/3); and migration (1/4 vs. 2/3). The GINA stent displayed better mechanical properties and comparable short-term performance, compared to the Dumon stent.

Park SY, et al. Allergy Asthma Immunol Res. 2024 May;16(3):253-266. https://doi.org/10.4168/aair.2024.16.3.253