[Inflammatory nature of colon diverticula]

On the basis of morphological and immunological study of biopsies of the colon in patients with diverticulosis was revealed that microscopic inflammation of the mouth of the diverticulum is characterized by several features that include excessive proliferation of the epithelium, the predominance of macrophage reaction in the development of the immune response, increased cell adhesion and unusual ratio between the expression of cytokines and other regulatory molecules. Changes in the structure of the formed diverticula tissue are associated with dysregulation of many processes of tissue metabolism and morphogenesis. These include the dysregulation of cell renewal of the epithelium (increased level of proliferation of epithelial cells and inhibition of apoptosis), degradation of extracellular matrix components, moderate vascular reaction. All these processes take place on the background a particular form of immune protection and adaptation mechanisms.

[Clinical value of serum cytokines in diverticular disease of the colon in elderly patients]

This article demonstrated changes in the level of pro-and anti-inflammatory cytokines in serum of patients of older age groups with small symptom diverticular disease of the colon. Was considered one of the links of the possible pathogenesis of this nosology, touched upon the contribution of involutive changes in the formation of the features of nonspecific immunity and the development of autoimmune reactions in elderly patients.

[Response of immunocompetent cells and structural changes of colon mucosa in patients with diverticulum disease]

It was established the activisation of macrophages and plasma cells with raise their adhesion in diverticular disease. The express of immune response depends on unit or plural diverticuls. Epithelial cells proliferation is on the increase in the cript and mouth region of diverticul. The small undifferential epithelial cells migrated from depth to top of cripts. These cells formed some fields of cells connected by means of branches. Therefore the chronic inflammation and local disturbance of epithelium regeneration were established in diverticular disease.

A hypothesis: is diverticulitis a type of inflammatory bowel disease?

It is accepted by epidemiologists that diverticula formation in the colon is related to a deficiency in dietary fiber intake, but the cause of acute diverticulitis remains unknown. A hypothesis is presented that acknowledges from the literature that fiber deficiency is also related to an altered intestinal microecology with a change in the bacterial flora. It is hypothesized that the change in the flora with a decrease in their influence on the immune process permits a low-grade chronic inflammation in the mucosa, which is the first step in developing an acute infection of diverticula or diverticulitis. There is some evidence that the low-grade chronic inflammation is present in subjects with diverticula, which is the forerunner of acute diverticulitis. This hypothesis is strengthened by early reports that anti-inflammatory mucosal agents such as mesalamine and immune process regulators such as probiotics may improve diverticulitis.

Diagnosis and treatment of chronic and recurrent diverticulitis

In Western countries the prevalence of diverticular disease has increased over the past century. Although, most patients remain asymptomatic, among those who experience an attack of diverticulitis, one-third will have recurrent symptoms, and a further third will have a subsequent episode. The indications for surgery after treatment of acute diverticulitis is still under debate. Uncomplicated disease less commonly as thought, progresses to a life threatening situation such as free perforation. Among those who develop complicated diverticulitis, it is often their first presentation. Fistula to the urinary tract often require surgery; however, complicated disease such as an abscess or phlegmon can be managed conservatively and subsequent surgery is selective depending on the recovery from the initial episode. Patients with chronic diverticular disease (persistent pain in the absence of inflammation) have greatly improved quality of life with surgery. The question of greater virulence of disease among young patients may no longer be true and recommendations for surgery may parallel that of older patients. Immunocompromised patients should have definitive surgical therapy early on in the course of the disease. Right-sided disease remains uncommon in the Western world and a conservative approach in the absence of free perforation is recommended. In right-sided disease and in young patients, misdiagnosis is common. In the elective setting, a laparoscopic approach is rapidly becoming preferred because of less morbidity and shorter hospital stay. The treatment of diverticular disease is rapidly undergoing reevaluation, and novel therapies and increased conservative approaches are evolving. Prospective randomized trials are needed, but remain difficult owing to the uncertain natural history of the disease.

How inflammation changes neuromuscular function and its relevance to symptoms in diverticular disease

Diverticulosis is largely asymptomatic but recent evidence suggests that episodes of acute diverticulitis double the risk of subsequently suffering from recurrent noninflammatory pain. Numerous animal models demonstrate how inflammation is followed by circular muscle hypertrophy, abnormalities of innervation, and increased sensitivity to cholinergic agents. There is also an impairment of norepinephrine and acetylcholine release and damage to nitrergic neurons. These changes are also associated with visceral hypersensitivity. Many of the features, including visceral hypersensitivity are also seen in symptomatic patients with diverticulosis. The trinitrobenzene sulfonic acid colitis model demonstrates that inflammation is followed by long lasting increases in tachykinin and other neuropeptide immunoreactivity. These changes occur both in the mucosa and myenteric plexus and parallel changes seen in resections and mucosal biopsies in diverticular patients. These neural abnormalities may be responsible for the visceral hypersensitivity, which explains why symptoms correlate poorly with objective abnormalities such as intraluminal pressure or motor patterns. Treatment of visceral hypersensitivity might be more effective than current therapies that often leave pain unaltered.

Severe diverticulitis after heart, lung, and heart-lung transplantation

BACKGROUND

In this study, we reviewed our experience with severe diverticulitis in patients who have undergone heart and/or lung transplantation to assess whether transplant recipients are at increased risk of having severe diverticulitis compared with the general population.

METHODS

We reviewed the records of patients who underwent heart and/or lung transplantation from 1984 to 2000, inclusive, and identified patients with severe diverticulitis that required surgery or that resulted in death. We compared this incidence with the incidence of such complications in the general population, served by the same institution during a 2-year period, 1999 to 2000.

RESULTS

A total of 953 patients underwent transplantation in the study period. The mean follow-up was 57 months, a total follow-up of 4528 patient-years. Nine patients (mean age, 54 years) had severe diverticulitis that required surgical intervention (8 patients) or that resulted in death (1 patient died without surgical intervention). During 1999 to 2000, 16 patients (mean age, 66 years) from the general population were treated for severe diverticulitis that required surgical intervention, 3 of whom died. From census and area health data, we found that the study institution serves approximately 90000 people older than 40 years, with a total follow-up of 180000 patient-years. The incidence rate ratio for severe diverticulitis when comparing the transplant with the non-transplant groups was 22.2 (95% confidence interval; 9.9-50.0; p < 0.001).

CONCLUSIONS

Patients with severe diverticulitis who have undergone heart and/or lung transplantation can be treated surgically with a small mortality rate. Transplant recipients probably are at substantially increased risk of experiencing severe diverticulitis.

Acute recurrent diverticulitis is prevented by oral administration of a polybacterial lysate suspension

AIM

The main cause of acute diverticulitis is the abnormal accumulation of fecal bacteria within the diverticular lumen, leading to a balancing between normal probiotic microflora and pathogenic species; Gram negative Entero-bacteriaceae, mainly Escherichia coli and Proteus spp, are the genders that usually cause the disease-related symptoms, due to their ability to adhere to intestinal mucosa. The intestine is well known as the largest human lymphoepithelial organ and daily produces more antibodies, mainly secretory IgAs, than do all other lymphoid tissues. IgAs have different immune and anti-inflammatory properties. The aim of this study was to verify the efficacy of an oral immunostimulant highly-purified, polymicrobial lysate in the prevention of recurrent attacks of diverticulitis and in the improvement of symptoms.

METHODS

The study was carried out on 83 consecutive patients suffering from recurrent symptomatic acute diverticulitis and with at least 2 attacks in the previous year; patients were randomly assigned to receive (group A) an oral polybacterial lysate suspension or to a no-treatment clinical follow-up as controls (group B).

RESULTS

A total of 76 patients (41 in group A and 35 in group B) terminated the study period. the sums of the scores for symptoms, reported on day schedules, were calculated and examined by means of ANOVA statistical analysis. Statistical differences between group A vs group B were recorded after 1 month (p<0.05) and 3 months (p<0.01) of treatment with the oral polybacterial lysate suspension.

CONCLUSIONS

Our data suggest that the administration of an oral enterovaccine for the prophylaxis of recurrent diverticulitis is effective and well tolerated, probably due to a direct stimulation of IgA-mediated mucosal defences.

T cell receptor delta repertoire in inflamed and noninflamed colon of patients with IBD analyzed by CDR3 spectratyping

Gamma/delta T cells might play an important role in autoimmune conditions like inflammatory bowel disease (IBD). In the present study, we characterized the T cell receptor (TCR)-delta repertoire by complementarity determining region 3 (CDR3) spectratyping in the inflamed and noninflamed mucosa and in the peripheral blood of subjects with Crohn's disease and ulcerative colitis. In contrast to previously published data about alpha/beta T cells, we rarely found oligoclonal expansions of gamma/delta T cells specific only for the inflamed mucosa. The same dominant gamma/delta T cell expansions were also present in the noninflamed colon. Furthermore, the peripheral gamma/delta TCR repertoire was oligoclonal but clearly distinct from that in the inflamed intestine. Thus our results do not support a role for antigen-specific gamma/delta T cells in IBD, and dominant gamma/delta T cells of the peripheral blood are not likely to be derived from the inflamed gut. However, in several patients, the TCR-delta-repertoire was highly diversified, whereas in others we observed a loss of dominant gamma/delta T cell clones when inflamed and noninflamed mucosa were compared. In conclusion, those changes indicate that gamma/delta T cells might play an important role in a subset of patients with IBD.

Expression of CD40 and its ligand, CD40L, in intestinal lesions of Crohn's disease

OBJECTIVE

Selected mechanisms of the immune system participate in the development of inflammatory bowel disease. Recently, overexpression of the ligand for CD40 (CD40L), a lymphocyte costimulatory molecule, was shown to induce severe inflammatory bowel disease in transgenic mice. In the present study, we examined the expression of CD40 and CD40L on surgical specimens of ileum from 12 patients with Crohn's disease and 10 patients with diverticulitis.

METHODS

Several CD40L+ cells were present in the affected tissue of patients with Crohn's disease, whereas few scattered CD40L+ cells were detected in sections of histologically normal ileum, resected distantly from the affected tissue, in patients with diverticulitis and in normal ileum portions obtained from colorectal cancer undergoing extensive surgery. The phenotype of CD40L+ cells was mainly CD4+.

RESULTS

In patients with Crohn's disease, several CD40+ cells were detectable in the same areas of lymphocytes expressing CD40L, whereas in patients with diverticulitis, the number of CD40+ cells was significantly lower. Most of the CD40+ cells costained with CD20, thus showing to be B-lymphocytes, and only a few were CD14+ macrophages. Several von Willebrand-positive vessels were also positive for CD40. In addition, several infiltrating macrophages were found to express B7-1 and B7-2 molecules, the ligands of CD28 and CTLA-4, which cooperate with the CD40-CD40L pathway in lymphocyte activation. Staining of ileal lesions with anti-CTLA-4 antibodies resulted in detection of none or very few positive cells. In contrast, in patients with diverticulitis, an enhanced number of B7-1 and B7-2 and CTLA-4 was observed.

CONCLUSION

The local accumulation of CD40L+ together with CD40+ cells within intestinal lesions of Crohn's disease suggests the involvement of this co-stimulatory pathway.

Granulomatous inflammation in sigmoid diverticulitis: two diseases or one?

AIMS

Histological appearances indistinguishable from Crohn's disease have been described in patients undergoing sigmoid colectomy for complicated diverticular disease. To investigate whether this finding represents coincidental dual pathology or merely a granulomatous colitis confined to the diverticular segment, we undertook clinical follow-up of affected patients.

METHODS AND RESULTS

Eight patients (median age 64 years, four males) whose sigmoid colectomy specimens showed acute diverticulitis and granulomatous inflammation were identified. All had a pre-operative diagnosis of diverticular disease and no previous evidence of Crohn's disease. Non-caseating epithelioid granulomas, unrelated to foreign material and usually unrelated to inflamed diverticular were present in the bowel wall of seven cases and in the regional lymph nodes of five. Three had granulomatous vasculitis and two had granulomas in 'background' mucosa. Mural lymphoid aggregates were identified in all cases. However, fissuring ulcers distinct from inflamed diverticula were not identified. On median follow-up of 51 months (range 18-112 months) none of the patients developed evidence of chronic inflammatory bowel disease. Three had died from unrelated causes.

CONCLUSIONS

Granulomatous inflammation appears to be part of a spectrum of sigmoid diverticulitis. In this setting, caution should be exercised to avoid an inappropriate diagnosis of Crohn's disease.

Acute diverticulitis. A complicated problem in the immunocompromised patient

We reviewed the records of 209 patients with acute diverticulitis treated from 1984 through 1989 to determine if immunocompromised patients have a worse prognosis than nonimmunocompromised patients. Forty immunocompromised patients and 169 nonimmunocompromised patients with acute diverticulitis were identified. Free perforation into the peritoneal cavity occurred in 43% (17/40) of immunocompromised patients and 14% (24/169) of nonimmunocompromised patients. Operations were performed in 58% (23/40) of immunocompromised patients and 33% (55/169) of nonimmunocompromised patients. Postoperative morbidity was 65% (15/23) in immunocompromised patients and 24% (13/55) in nonimmunocompromised patients; postoperative mortality was 39% (9/23) and 2% (1/55), respectively. We conclude that acute diverticulitis in the immunocompromised patient is a complicated problem; there is a greater risk of free perforation and need for surgery than in the nonimmunocompromised patient. Furthermore, the prognosis for immunocompromised patients who undergo surgery is worse than that for nonimmunocompromised patients.