Tetsuo Kawashima

Cutting Edge: Major CD8 T Cell Response to Live Bacillus Calmette-Guérin Is Mediated by CD1 Molecules

MHC class I-restricted CD8+ T cells are a crucial component of the host defense against mycobacterial infection in mice, but it has often proved very difficult to identify the CD8 T cell response in humans. Human group 1 CD1 molecules (CD1a, -b, -c) mediate MHC-independent presentation of mycobacteria-derived lipid and glycolipid Ags to CD8+ T cells, and their intracellular localization to the endocytic system may favor efficient monitoring of phagosome-resident mycobacteria. Here, we show that bacillus Calmette-Guérin (BCG)-immunized subjects contain a significant circulating pool of CD8+ T cells that recognize BCG-infected DCs in a CD1-dependent, but MHC-independent, manner. These CD1-restricted T cells efficiently detected live, rather than dead, BCG and produced IFN-γ, an important cytokine for protection against mycobacterial infection. These results emphasize that lipid-reactive CD8+ T cells may contribute to host defense against mycobacterial infection.

Covering the staple line with a polyglycolic acid sheet after bullectomy for primary spontaneous pneumothorax prevents postoperative recurrent pneumothorax

BACKGROUND Postoperative recurrent pneumothorax (PORP) can arise after surgery for primary spontaneous pneumothorax (PSP) that is recurrent or involves prolonged air leakage. In this study, which included 265 patients (279 cases) with PSP who underwent surgery at our department, the percentage of patients that did not experience PORP was compared between a group that underwent bullectomy alone (group A) and a group in which the staple line and the surrounding visceral pleura were covered with a PGA sheet after bullectomy (group B) in order to study the utility of PGA sheets for preventing PORP. METHODS Among the patients with PSP who underwent surgery, the cases of 92 patients (98 cases) from Group A and 173 patients (181 cases) from Group B were reviewed retrospectively. The incidence rates of PORP in these two groups were statistically analyzed in addition to the associations between PORP and age, gender, the affected side, height, body weight, height/weight ratio, smoking habits, or the surgical procedure. RESULTS In total, 96.7% of the patients in group B did not suffer PORP, which was significantly higher than the equivalent figure for group A (83.7%, log-rank test: P=0.0003). Moreover, among the examined parameters, only covering the staple line with a PGA sheet was found to be an independent prognostic factor (Cox regression: P=0.0003; HR =0.212; 95% CI, 0.082-0.547). CONCLUSIONS It was revealed that when bullectomy is performed in patients with PSP, wide coverage of the staple line and the surrounding visceral pleura with a PGA sheet significantly reduces the risk of PORP.