T-cell activation Rho GTPase-activating protein expression varies with inflammation location and severity in Crohn's disease.

BACKGROUND: The T-cell activation Rho GTPase-activating protein (TAGAP) gene has a regulatory role in T cell activation. We have previously suggested a correlation between the TAGAP-associated single nucleotide polymorphism rs212388 and protection from anal sepsis in Crohn's disease (CD) patients. The present study sought to evaluate TAGAP's expression in colonic tissue of CD patients with varying disease severity and location. MATERIALS AND METHODS: Five transverse, 17 left, and five sigmoid colectomy specimens from 27 CD patients with varying disease severity (16 male, mean age at diagnosis 26.4 ± 2.2 y) were evaluated for TAGAP messenger RNA expression. Fisher exact, Mann-Whitney, and Welch two-sample t-tests were used for statistical evaluation. Immunohistochemistry confirmed results. RESULTS: Patients with tissue demonstrating lower TAGAP messenger RNA expression (less than the overall mean) were younger at diagnosis (mean age 21.1 ± 6.3 versus 32.5 ± 13 y, P = 0.009). Increased TAGAP expression was seen in moderate or severely diseased tissue versus tissue with no or mild disease (RQ = 1.3 ± 0.34 versus 0.53 ± 0.09, P = 0.050). This was the most dramatic in the sigmoid colon (P = 0.041). TAGAP expression was increased in more distal tissue with a significant difference seen when comparing transverse versus sigmoid colon with moderate or severe disease (0.51 ± 0.14 versus 1.9 ± 0.37, P = 0.049). CONCLUSIONS: Colonic expression of TAGAP in CD patients varied according to disease severity and location, being the most elevated in patients with severe disease in the sigmoid colon. Whether changes in TAGAP expression are a result of disease response or inherent to the disease pathophysiology itself remains to be determined. This gene warrants further investigation for its role in CD.

Increased risk of incisional hernia after sigmoid colectomy for diverticulitis compared with colon cancer.

BACKGROUND: We aimed to determine if an increased incidence of incisional hernias is present in patients undergoing sigmoidectomy for diverticulitis vs cancer. The pathophysiology of diverticulitis is poorly understood, but might involve a collagen vascular abnormality that can predispose to incisional hernia. STUDY DESIGN: In this IRB-approved, retrospective study, patients who underwent sigmoid colectomies for diverticulitis or cancer between January 2003 and September 2012 were studied. Exclusion criteria included the development of surgical site infections and neoadjuvant chemoradiotherapy. A multivariate logistic regression was used with covariate adjustments for known risk factors for hernia development. RESULTS: Four hundred forty-two patients (mean age 59.3 ± 13.9 years) with a median follow-up of 30 months were analyzed. The incidence of incisional hernia was 15.1% in diverticulitis patients vs 5.8% in the cancer cohort (41 of 271 vs 10 of 171; p = 0.003). Univariate analysis of risk factors associated with postoperative incisional hernia included steroid use (p = 0.007), wound packing (p = 0.001), higher American Society of Anesthesiologists classification (p = 0.001), absorbable suture closure (p = 0.02), blood transfusion (p = 0.04), stoma formation (p = 0.02), increased body mass index (p = 0.008), and history of incisional hernia (p = 0.00008). Multivariate logistic regression demonstrated a persistent association between diverticulitis and hernia development (p = 0.01). Odds of a hernia developing after sigmoidectomy for diverticulitis were 2.82 times greater than in the cancer cohort (95% CI, 1.3-6.6). CONCLUSIONS: The incidence of an incisional hernia developing after a sigmoid colectomy is significantly higher when performed for diverticulitis as compared with cancer. This might be due to a connective tissue disorder, which predisposes to development of both diverticula and hernias.