Preventing diverticulitis recurrence by selecting the right therapy for a complex disease

Role of Inflammation in the Pathogenesis of Diverticular Disease

Diverticulosis of the colon is the most common condition in Western societies and it is the most common anatomic alteration of the human colon. Recurrent abdominal pain is experienced by about 20% of patients with diverticulosis, but the pathophysiologic mechanisms of its occurrence are not completely understood. In the last years, several fine papers have showed clearly the role of low-grade inflammation both in the occurrence of symptoms in people having diverticulosis, both in symptom persistence following acute diverticulitis, even if the evidence available is not so strong. We do not know yet what the trigger of this low-grade inflammation occurrence is. However, some preliminary evidence found colonic dysbiosis linked to low-grade inflammation and therefore to symptom occurrence in those patients. The aim of this paper is to summarize current evidences about the role of inflammation in symptom occurrence in symptomatic uncomplicated diverticular disease and in symptom persistence after an episode of acute diverticulitis.

Colonic Diverticula Are Not Associated With Mucosal Inflammation or Chronic Gastrointestinal Symptoms

BACKGROUND & AIMS

Colonic diverticulosis has been reported to be associated with low-grade mucosal inflammation, possibly leading to chronic gastrointestinal symptoms. However, there is poor evidence for this association. We aimed to determine mucosal inflammation and whether diverticula are associated with chronic gastrointestinal symptoms. We explored whether inflammation was present among symptomatic participants with and without diverticula.

METHODS

We analyzed data from a prospective study of 619 patients undergoing a screening colonoscopy from 2013 through 2015 at the University of North Carolina Hospital in Chapel Hill, North Carolina. Among our participants, 255 (41%) had colonic diverticula. Colonic mucosal biopsy specimens were analyzed for levels of interleukin 6 (IL6), IL10, and tumor necrosis factor messenger RNAs by quantitative reverse-transcriptase polymerase chain reaction, and numbers of immune cells (CD4+, CD8+, CD57+, and mast cell tryptase) by immunohistochemistry. Gastrointestinal symptoms were assessed using Rome III criteria. Proportional odds models were used to estimate odds ratios (ORs) and 95% confidence interval (CIs).

RESULTS

After adjustment for potential confounders, there was no association between diverticulosis and tumor necrosis factor (OR, 0.85; 95% CI, 0.63-1.16), and no association with CD4+ cells (OR, 1.18; 95% CI, 0.87-1.60), CD8+ cells (OR, 0.97; 95% CI, 0.71-1.32), or CD57+ cells (OR, 0.80; 95% CI, 0.59-1.09). Compared with controls without diverticulosis, biopsy specimens from individuals with diverticulosis were less likely to express the inflammatory cytokine IL6 (OR, 0.59; 95% CI, 0.36-0.96). There was no association between diverticulosis and irritable bowel syndrome (OR, 0.53; 95% CI, 0.26-1.05) or chronic abdominal pain (OR, 0.68; 95% CI, 0.38-1.23). There was no evidence for inflammation in patients with symptoms when patients with vs without diverticulosis were compared.

CONCLUSIONS

We found no evidence that colonic diverticulosis is associated with mucosal inflammation or gastrointestinal symptoms. Among patients with symptoms and diverticula, we found no mucosal inflammation.

Diverticular Disease: Traditional and Evolving Paradigms

Diverticular disease includes diverticulosis, which are sac protrusions of the intestinal mucosa, and diverticulitis, inflammation of the diverticula. Diverticular disease is listed as one of the top 10 leading physician diagnoses for gastrointestinal disorders in outpatient clinic visits in the United States. There are several classifications of diverticular disease ranging from asymptomatic diverticulosis to diverticulitis with complications. Several theories are linked to the development of diverticula which includes the physiology of the colon itself, collagen cross-linking, and recently challenged, low-fiber intake. The differential diagnoses of lower abdominal pain in addition to diverticular disease have overlapping signs and symptoms, which can make a diagnosis challenging. Identification of the distinct signs and symptoms of each classification will assist the practitioner in making the correct diagnosis and lead to appropriate management. The findings from recent studies have changed the paradigm of diverticular disease. The purpose of this article is to discuss traditional dogma and evolving concepts in the pathophysiology, prevention, and management of diverticular disease. Practitioners must be knowledgeable about diverticular disease for improved outcomes.

Prognostic Role of the Endoscopic Classification "DICA"

Diverticular inflammation and complication assessment (DICA) endoscopic classification has been recently developed for patients suffering from diverticulosis and diverticular disease. Its predictive value in those patients was recently retrospectively assessed. For each patient, the following parameters were recorded: age, severity of DICA, presence of abdominal pain, C-reactive protein, fecal calprotectin test (if available) at the time of diagnosis, months of follow-up, therapy taken during the follow-up to maintain remission (if any), occurrence/recurrence of diverticulitis, and need of surgery. A total of 1651 patients (793 male, 858 female, mean age 66.6±11.1 y) were enrolled: 939 (56.9%) classified as DICA 1, 501 (30.3%) as DICA 2, and 211 (12.8%) as DICA 3. The median follow-up was 24 (9 to 138) months. Acute diverticulitis (AD) occurred/recurred in 263 (15.9%) patients, and surgery was necessary in 57 (21.7%) cases. DICA was the only factor significantly associated with the occurrence/recurrence of diverticulitis and surgery either at univariate (χ=405.029; P<0.0001) or multivariate analysis (hazard ratio=4.319; 95% CI, 3.639-5.126; P<0.0001). Only in DICA 2 patients scheduled therapy was effective for prevention of AD occurrence/recurrence with a hazard ratio (95% CI) of 0.598 (0.391-0.914) (P=0.006, log-rank test). Mesalazine-based therapies reduced the risk of AD occurrence/recurrence and need of surgery with a hazard ratio (95% CI) of 0.2103 (0.122-0.364) and 0.459 (0.258-0.818), respectively. DICA classification seems to be a valid parameter to predict the risk of diverticulitis occurrence/recurrence in patients suffering from diverticular disease of the colon.

Predictive value of the Diverticular Inflammation and Complication Assessment (DICA) endoscopic classification on the outcome of diverticular disease of the colon: An international study

BACKGROUND

Diverticular Inflammation and Complication Assessment (DICA) endoscopic classification has been recently developed for patients suffering from diverticulosis and diverticular disease.

AIMS

We assessed retrospectively the predictive value of DICA in patients for whom endoscopic data and clinical follow-up were available.

METHODS

For each patient, we recorded: age, severity of DICA, presence of abdominal pain, C-reactive protein and faecal calprotectin test (if available) at the time of diagnosis; months of follow-up; therapy taken during the follow-up to maintain remission (if any); occurrence/recurrence of diverticulitis; need of surgery.

RESULTS

We enrolled 1651 patients (793 M, 858 F, mean age 66.6 ± 11.1 years): 939 (56.9%) patients were classified as DICA 1, 501 (30.3%) patients as DICA 2 and 211 (12.8%) patients as DICA 3. The median follow-up was 24 (9-38) months. Acute diverticulitis (AD) occurred/recurred in 263 (15.9%) patients; surgery was necessary in 57 (21.7%) cases. DICA was the only factor significantly associated to the occurrence/recurrence of diverticulitis and surgery either at univariate (χ(2 )= 405.029; p < 0.0001) or multivariate analysis (hazard ratio = 4.319, 95% confidence interval (CI) 3.639-5.126; p < 0.0001). Only in DICA 2 patients was therapy effective for prevention of AD occurrence/recurrence with a hazard ratio (95% CI) of 0.598 (0.391-0.914) (p = 0.006, log rank test). Mesalazine-based therapies reduced the risk of AD occurrence/recurrence and needs of surgery with a hazard ratio (95% CI) of 0.2103 (0.122-0.364) and 0.459 (0.258-0.818), respectively.

CONCLUSIONS

DICA classification is a valid parameter to predict the risk of diverticulitis occurrence/recurrence in patients suffering from diverticular disease of the colon.