Prolonged Recurrent Abdominal Pain is Associated With Ongoing Underlying Mucosal Inflammation in Patients who had an Episode of Acute Complicated Diverticulitis.

Abstract

Recent data suggest continuous chronic inflammation in patients after an acute diverticulitis (AD) episode. The aim of this article was to compare clinical parameters, inflammatory cytokine expression, and immune-cell infiltrates between patients after severe versus nonsevere AD, as defined by radiology examination during the acute episode. Sixteen patients, after suffering an episode of AD, were included, and, of them, 8 had severe disease. Demographic data, disease characteristics, and inflammatory markers were collected. Tissue samples from diverticular and unaffected tissue were obtained during colonoscopy. Mucosal inflammation was assessed histologically and by measuring inflammatory cytokine mRNA expression. Clinically, continued nonspecific abdominal symptoms were significantly more prevalent among patients after severe AD compared with patients after nonsevere AD (P=0.0002). Patients after severe AD also had significantly higher C reactive protein levels (9.85±7.5 vs. 3±2.1 mg/dL; P=0.027) and tendency for higher calprotectin levels (115.7±85 vs. 35±8.7 mg/g; P=0.08). Reverse transcription polymerase chain reaction-determined cytokines levels were 5.4±4.4, 5.14±10, and 0.8±0.82 for tumor necrosis factor alpha, interleukin-6, and interleukin-1β, respectively, in affected mucosa compared with 1.06±1.57, 1.56±2.1, and 0.35±0.5, respectively, in nonaffected mucosa (P=0.01, 0.05, 0.14, respectively). Cytokine expression in patients after nonsevere AD did not differ significantly between affected and nonaffected mucosa. Histologic scores for crypt distortion, lymphoid aggregates, and lymphocyte infiltration were all significantly higher in patients after severe AD compared with patients after nonsevere AD (P<0.05 for all comparisons). Patients after severe AD have more prolonged chronic symptoms, higher inflammatory markers, higher tissue inflammatory cytokine levels, and more inflammatory infiltrates in diverticular colonic tissue than patients after nonsevere AD. These results may contribute to patients' risk stratification and guide therapeutic decisions.