Sarcopenia, the depletion of muscle mass, an independent predictor of respiratory complications after oncological esophagectomy

Surgery for esophageal carcinoma is known to be associated with high morbidity. Recent studies have reported a correlation of nutritional and inflammatory parameters with postoperative course. This study aims to clarify the risk factors for operative morbidity after resection of esophageal carcinoma. Consecutive patients who underwent esophagectomy for esophageal squamous cell carcinoma at our institute were included (n = 102; 89 males and 13 females; mean age: 67.3 years). Clinicopathological characteristics, presence or absence of sarcopenia, and modified Glasgow prognostic score were assessed, and their correlation with postoperative complications was investigated using univariate and multivariate analyses. Sarcopenia was defined using a combination of muscle mass area and body mass index. Of the included 102 patients, 45 (44.1%) exhibited sarcopenia (sarcopenia group), while 57 (55.9%) did not (non-sarcopenia group). No significant difference was observed between the groups regarding surgical procedures and tumor stage; furthermore, there was no mortality. Twenty-six patients developed respiratory complications (including 20 cases of pneumonia). On univariate analysis, sarcopenia, modified Glasgow prognostic score, and American Society of Anesthesiologists physical status were found to be significantly associated with the development of postoperative respiratory complications. On multivariate analysis, sarcopenia was found to be an independent risk factor for postoperative respiratory complications after esophagectomy. We believe that identifying patients at risk and providing preoperative nutritional support as well as physical therapy aimed at strengthening of body muscles may help reduce the incidence of postoperative respiratory complications in such patients.

TWEAK/Fn14 pathway promotes a T helper 2-type chronic colitis with fibrosis in mice

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), a TNF superfamily member, induces damage of the epithelial cells (ECs) and production of inflammatory mediaters through its receptor Fn14 in a model of acute colitis. In our current study of chronic colitis induced by repeated rectal injection of a hapten, we found that inflammation, fibrosis, and T helper 2 (Th2)-type immunity were significantly reduced in Fn14 gene knockout (KO) mice when compared with wild-type (WT) control mice. Expression of thymic stromal lymphopoietin (TSLP) was lower in Fn14 KO colon ECs than in WT ECs. TWEAK potentiates the induction of TSLP by interleukin-13 (IL-13) in colon explants from WT but not in Fn14 KO tissue. TSLP receptor KO mice exhibit milder chronic colitis, similar to that in Fn14 KO mice. TWEAK and IL-13 synergistically promote fibroblast proliferation. Thus we propose an IL-13-TWEAK/Fn14-TSLP axis as a key mechanism underlying chronic colitis with fibrosis.

Elimination of colonic patches with lymphotoxin beta receptor-Ig prevents Th2 cell-type colitis

Past studies have shown that colonic patches, which are the gut-associated lymphoreticular tissues (GALT) in the colon, become much more pronounced in hapten-induced murine colitis, and this was associated with Th2-type T cell responses. To address the role of GALT in colonic inflammation, experimental colitis was induced in mice either lacking organized GALT or with altered GALT structures. Trinitrobenzene sulfonic acid was used to induce colitis in mice given lymphotoxin-beta receptor-Ig fusion protein (LTbetaR-Ig) in utero, a treatment that blocked the formation of both Peyer's and colonic patches. Mice deficient in colonic patches developed focal acute ulcers with Th1-type responses, whereas lesions in normal mice were of a diffuse mucosal type with both Th1- and Th2-type cytokine production. We next determined whether LTbetaR-Ig could be used to treat colitis in normal or Th2-dominant, IFN-gamma gene knockout (IFN-gamma(-/-)) mice. Four weekly treatments with LTbetaR-Ig resulted in deletion of Peyer's and colonic patches with significant decreases in numbers of dendritic cells. This pretreatment protected IFN-gamma(-/-) mice from trinitrobenzene sulfonic acid-induced colitis; however, in normal mice this weekly treatment was less protective. In these mice hypertrophy of colonic patches was seen after induction of colitis. We conclude that Th2-type colitis is dependent upon the presence of colonic patches. The effect of LTbetaR-Ig was mediated through prevention of colonic patch hypertrophy in the absence of IFN-gamma. Thus, LTbetaR-Ig may offer a possible treatment for the Th2-dominant form of colitis.