A quantitative study of immunoglobulin containing cells in the differential diagnosis of acute colitis

Pouchitis

Pouchitis is one of the commonest and most debilitating complications of a restorative proctocolectomy. The cause remains elusive, though a number of approaches have been shown to alleviate the condition. This review outlines current evidence relating to pouchitis, obtained from randomised and nonrandomised studies. Medline, the Bath Information Data Service (BIDS) and PubMed were searched using the keywords 'pouchitis' and 'inflammatory bowel disease'. In addition, articles were cross-referenced, and the abstracts of recent colorectal meetings studied.

Increased state of activation of CD4 positive T cells and elevated interferon gamma production in pouchitis

BACKGROUND

Immunoregulatory abnormalities of T cells might be of importance in the pathogenesis of pouchitis after ileoanal pouch anastomosis (IAP).

AIMS

To characterise T cell subsets, their state of activation, and production of cytokines in inflamed and non-inflamed pouches in patients with ulcerative colitis (UC) and familial adenomatous polyposis (FAP). The influence of T cell activation on mucosal transformation was also studied.

PATIENTS

Mucosal biopsy specimens were taken from 42 patients with IAP (33 with UC and nine with FAP).

METHODS

Mononuclear cells were isolated by standard techniques and characterised by three colour flow cytometry. Interferon gamma (IFN-gamma) production was studied using the ELISPOT technique.

RESULTS

In patients with UC with pouchitis there was a significant increase in the CD4:CD8 ratio, expression of activation markers on CD3+ cells, and number of IFNgamma producing mononuclear cells compared with patients with UC without pouchitis (CD4:CD8 ratio 1.3 (range 0.7-2.7) versus 0.6 (0. 1-1.0), p=0.012). In addition, a positive correlation between increased crypt depth and the number of CD4+ cells (r=0.57) was shown.

CONCLUSION

The observed increase in activated mucosal CD4+ T cells and IFN-gamma production might lead to mucosal destruction and crypt hyperplasia as seen in pouchitis.

Quantitative assessment of IgG and IgA subclass producing cells in rectal mucosa during shigellosis

AIMS

To assess quantitatively both the morphological changes in the rectal mucosa and the changes in the relative frequency of IgA and IgG subclass producing cells found in the rectal mucosa during the acute phase of shigellosis and at convalescence.

METHODS

Rectal biopsies from 25 Shigella dysenteriae 1 infected patients, 10 Shigella flexneri infected patients, and 40 uninfected controls were studied. Morphological changes in the mucosa were graded. The frequency of IgA and IgG subclass producing cells was assessed. In addition, immunostaining for secretory component in epithelial cells was analysed.

RESULTS

Using morphological grading, 20% of the 35 patients studied had advanced inflammation (grade 3) in the acute phase of the disease. At convalescence, grade 1 inflammation was seen in 37% of the patients and in 10% of the controls. In the acute phase, as well as at convalescence, the number of IgA1, IgA2, and IgG2 positive cells was significantly higher than in the controls. The results were related to the histopathological degree of inflammation.

CONCLUSIONS

In shigellosis, there is evidence for a prolonged humoral response residing in the mucosa long after the clinical symptoms have resolved, suggesting that shigellosis induces persisting mucosal humoral immune and inflammatory responses, remaining at least until 30 days after the infection.

Ileal pouches: adaptation and inflammation

Ileal pouch-anal anastomosis (IPAA) has become the operation of choice following proctocolectomy for ulcerative colitis (UC) and familial adenomatous polyposis. Functioning ileal pouch mucosa undergoes histological changes resembling the colon (colonic metaplasia). The possible role of stasis and luminal factors--bile acids, short-chain fatty acids and bacteria--are discussed. It seems likely that colonic metaplasia is an adaptive response to the new luminal environment in IPAA. Inflammation in the ileal reservoir ('pouchitis') is the most significant late complication in IPAA. It occurs in 20-30% of patients and is virtually confined to those with prior UC. The clinical picture in pouchitis is highly variable; however, it can be easily categorized into three groups. Nevertheless, in most cases it is likely to represent recurrent UC in the ileal pouch. Current treatments and possible preventative strategies for pouchitis have been outlined.

Ulcerative colitis: an immunological disease?

Ulcerative colitis is an inflammatory disease of the large intestine of unknown aetiology. The nature of the inflammatory infiltrate together with the response to corticosteroids suggests that an abnormal immune response is at work. The key question of whether the immune system is responding to an abnormal breach in the mucosa due to another primary abnormality or whether the primary defect lies within the immune response itself has not been answered. Thus far, it is clear that both T and B cell compartments are involved in the persistence of inflammation but the initial interactions that take place in the mucosa in terms of antigen processing and presentation have not been adequately investigated. Those critical steps and potential defects that push T cells and B cells into a heightened state of activation need to be identified.

Alterations of the mucosal immune system in inflammatory bowel disease

The normal intestinal immune system is under a balance in which proinflammatory and anti-inflammatory cells and molecules are carefully regulated to promote a normal host mucosal defense capability without destruction of intestinal tissue. Once this careful regulatory balance is disturbed, nonspecific stimulation and activation can lead to increased amounts of potent destructive immunologica and inflammatory molecules being produced and released. The concept of balance and regulation of normal mucosal immune and inflammatory events is indicative of how close the intestine is to developing severe inflammation. The normal intestinal mucosal immune system is constantly stimulated by lumenal contents and bacteria. The stimulatory molecules present in the intestinal lumen that activate and induce subsequent mucosal immunologic and inflammatory events include bacterial cell wall products, such as peptidoglycans and lipopolysaccharides, as well as other chemotactic and toxic bacterial products that are produced by the many different types of bacteria within the gastrointestinal tract. These highly stimulatory bacterial cell wall products are capable of activating macrophages and T lymphocytes to release potent proinflammatory cytokines, including interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha). IL-1, IL-6, and TNF-alpha increase the presence of human leukocyte antigen (HLA) class II antigen-presenting molecules on the surfaces of epithelial cells, endothelial cells, macrophages, and B cells, thus increasing their ability to present lumenal antigens and bacterial products. The proinflammatory cytokines IL-1 and TNF-alpha also increase the ability of epithelial cells, endothelial cells, macrophages, and fibroblasts to secrete potent chemotactic cytokines, such as interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1), which serve to increase the movement of macrophages and granulocytes from the circulation into the inflamed mucosa. Thus, through lumenal exposure to potent, nonspecific stimulatory bacterial products, the state of activation of the intestinal immune system and mucosal inflammatory pathways are markedly up-regulated. This raises the question of whether there is a deficiency in effective down-regulation through the absence of normally suppressive cytokines such as interleukin-10 (IL-10), transforming growth factor-beta (TGF-beta), interleukin-4 (IL-4), and IL-1 receptor antagonist. Normally, the turning off of the active and destructive immunologic and inflammatory events should occur following the resolution of a bacterial or viral infection that has been appropriately defended against and controlled by the mucosal immune system. In inflammatory bowel disease (IBD), however, the down-regulatory events and processes that should turn off the immunologic and inflammatory protective processes, once the pathogenic agent has been cleared, appear to be deficient or only partially effective. We may find that we ultimately are dealing with disease processes that have more than one genetic or cellular basis. The improved understanding of the immunopathophysiology of IBD will allow exploration of novel immunologic and genetic approaches, such as gene replacement therapy, administration of a suppressor cytokine or an altered cell surface antigen, the administration of humanized monoclonal antibodies directed against proinflammatory cytokines, or the development of newer strategies against fundamental cell biologic mechanisms such as adhesion molecules.

Alterations in the mucosal immune system in ulcerative colitis and Crohn's disease

Emphasis is now being placed upon obtaining a better understanding of the regulatory cytokines that normally downregulate acute intestinal inflammation. These inhibitory cytokines appear to be missing or not functioning properly in patients with inflammatory bowel disease (IBD), thereby leading to perpetuation of inflammation. As we obtain an increased understanding of immune and inflammatory regulatory processes in the intestine, we will be able to devise better future therapeutic strategies for use in our IBD patients.

Immunoglobulin-containing cells in the colonic mucosa in patients with human intestinal spirochaetosis

The relative proportions of cells containing the various classes of immunoglobulins in the colonic mucosa were determined in eight patients with human intestinal spirochaetosis (HIS) and in eight controls. All specimens were taken from colonic resections performed because of adenocarcinoma. None of the cases with HIS showed an inflammatory reaction in the mucosa as judged subjectively by light microscopy. Cases with HIS had smaller proportions of IgD- and IgE-positive cells and a larger proportion of IgA cells as compared with the controls, whereas the proportions of IgG and IgM cells were similar in the two groups. Taking into account the large individual variations in the proportions of immunoglobulins in both groups, our findings must be interpreted with caution. However, our results do not support the previous demonstration of increased percentages of IgE-positive cells in patients with HIS.

Mucosal concentrations of interleukin-1 beta, interleukin-6, interleukin-8, and tumor necrosis factor-alpha in pelvic ileal pouches

Concentrations of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-alpha) were determined by solid-phase ELISA in tissue homogenates of mucosal biopsy specimens obtained from pelvic ileal pouches in 13 patients with pouchitis (reservoir ileitis) and 17 with pouches without pouchitis. Normal ileal mucosa was used as a control. IL-1 beta was detected in all tissue homogenates from patients with pouchitis compared with only 29% from pouches without pouchitis and none from controls. IL-6 and IL-8 were present in all pouchitis specimens, in 70% of the specimens from nonpouchitis and only 30% of specimens from controls. TNF-alpha was undetectable in all specimens examined. The concentrations of IL-1 beta, IL-6, and IL-8 were significantly greater (P < 0.001) in biopsy specimens from pouchitis compared to those from pouches without pouchitis or normal ileal mucosa and in patients with pouchitis tissue levels of IL-1 beta significantly correlated with IL-6 (P < 0.05) and IL-8 (P < 0.01). Furthermore IL-1 and IL-8 levels were significantly higher in tissue specimens from nonpouchitis pouches than in those from normal ileal mucosa (P < 0.02). These results suggest that an enhanced cellular immunity operates in vivo at the mucosal level in pouchitis as in the case of ulcerative colitis.

Value of counting colonic mucosal Ig-containing cells in the differential diagnosis of chronic inflammatory bowel disease

AIMS

To investigate whether counting cells containing immunoglobulin (Ig) subclass in colonic biopsy specimens of patients with chronic inflammatory bowel disease, in addition to conventional histological evaluation, can improve the differentiation of patients with Crohn's disease from those with ulcerative colitis.

METHODS

The colonic and rectal biopsy specimens of 40 patients with chronic inflammatory bowel disease, comprising 20 patients with Crohn's disease and 20 with ulcerative colitis, were used and sections were stained specifically for IgA, IgM, and IgG heavy chains using an indirect immune peroxidase method. The immunoglobulin subclass containing cells were counted using an ocular grid counting method in a light microscope. A linear stepwise discriminant analysis was performed on Ig subclass containing cell counts in combination with 16 reproducible histological features. The results of this discriminant analysis were compared with the results of the discriminant analyses in which only the histological features were used.

RESULTS

Applying stepwise discriminant analysis, two histological features (an excess of histiocytes in the lamina propria and the villous or irregular aspect of the mucosal surface) in combination with IgMax were selected as the most discriminatory parameters that distinguish Crohn's disease from ulcerative colitis. IgMmax was defined as the maximum value of the mean percentage of IgM containing cells over all the biopsy locations. The use of this combination resulted in a better classification in 20% of the patients with Crohn's disease and in 9% of the patients with ulcerative colitis compared with the use of histological features alone.

CONCLUSIONS

Morphometric enumeration of Ig subclass containing cells in colonic mucosal biopsy specimens has diagnostic value as a means of differentiating individual patients with Crohn's disease from those with ulcerative colitis.

Lymphoid cell subsets in colonic mucosa and HLA-DR antigens on colonic epithelia in colitis excluding ulcerative colitis and Crohn's disease

Lymphoid cell subsets, including T cells as well as Ig-containing cells in the colonic mucosa and HLA-DR antigens on colonic epithelia, were examined in non-IBD colitis (colitis excluding ulcerative colitis (UC) and Crohn's disease) by the indirect immunoperoxidase staining method. Mouse anti-CD5, CD8, CD4, IgG, IgA1, IgA2, IgM, IgD, IgE, HLA-DR, and NuIa monoclonal antibodies were used as the first antibody. The results were compared to those of the normal controls and UC. T cell subsets in non-IBD colitis were almost similar to those of the controls and UC. The number of Ig-containing cells of all classes, except for IgA, tended to be increased in non-IBD colitis. In particular, both IgG- and IgE-containing cells were significantly increased compared to those in the controls. Compared to UC, IgG-containing cells were decreased in non-IBD colitis. Namely, in non-IBD colitis, as well as in UC, the change of Ig-containing cells (B cell lineage) was more pronounced than that of T cells. The frequency of the expression of HLA-DR antigens on colonic epithelia in non-IBD colitis was 70%, which was significantly higher than that in controls (0%), but significantly lower than that in UC (100%). Whether the differences in the number of IgG-containing cells, and the frequency of epithelial HLA-DR expression between non-IBD colitis and UC was due to the differences of the degree of local inflammation or due to the differences of the nature of the two diseases was not elucidated in this study.

Immunoglobulin containing cells in terminal ileum and colorectum of patients with arthritis related gut inflammation

In 40 distal ileal and 40 colonic biopsies of arthritic patients mostly without gastrointestinal symptoms, but with histological evidence of acute or chronic inflammation of the gut, the number of immunoglobulin (Ig) containing plasma cells was studied morphometrically using a peroxidase antiperoxidase technique. Compared with controls, the ileal mucosal biopsies showed an increase of IgA and IgG in acute ileitis. In chronic ileitis there was an increase of IgA, IgG, and IgM similar to Crohn's disease. In colonic biopsies there was a significant increase of all immunoglobulin classes in acute inflammation. In chronic inflamed mucosa there was also an increase of all three Ig classes. The Ig distribution, however, was significantly different in acute and chronic colitis. These findings give immunohistochemical evidence of the existence of two different types of inflammation related to reactive arthritis or the peripheral joint involvement of ankylosing spondylitis. The Ig pattern in acute colitis is similar to that found in infectious colitis, suggesting an enterobacterial origin of the arthritis in this group of patients although bacteriological and serological investigations were negative. In the chronic type of arthritis related ileocolitis, the pattern of Ig containing cells is similar to that found in Crohn's disease but different from infectious and ulcerative colitis, which makes the hypothesis that a great number of these arthritis patients suffer from asymptomatic or subclinical Crohn's disease acceptable.

What is colitis? Statistical approach to distinguishing clinically important inflammatory change in rectal biopsy specimens

Measurements of mucosal dimension, architecture, and cell counts in both lamina propria and epithelium were made on rectal biopsy specimens from 20 patients with irritable bowel syndrome ("normal" controls); 54 patients with ulcerative colitis, Crohn's disease, and non-specific proctitis; eight patients with small bowel Crohn's disease; and 34 in whom the rectal biopsy specimen was not diagnostic. Discriminant analysis was applied to multiple variables based on the measurements, and three variables were identified as of high predictive value. The most powerful discriminant was increased lamina propria cellularity in all forms of chronic colitis. The ratios of surface length to mucosal length and of surface epithelial height to crypt epithelial height also emerged as discriminants. Chronic inflammatory bowel disease was distinguished from normal in 95% of cases with a definite pathological diagnosis, and 85% of borderline cases were correctly classified as either normal or inflammatory when judged by the final diagnosis after follow up. This study provides a basis for automated diagnosis of rectal biopsy specimens and provides objectively validated criteria which can also be applied in routine histological diagnosis.

A comparison of cytoplasmic immunoglobulins in retroperitoneal fibrosis and abdominal aortic aneurysms

Retroperitoneal fibrosis is associated with Riedel's thyroiditis, in which an unexpectedly high proportion of the plasma cells have been reported to contain IgA and lambda light chains. It has been suggested that retroperitoneal fibrosis and the inflammation and fibrosis in thick-walled abdominal aortic aneurysms are caused by a hypersensitivity reaction to antigens leaked from aortic atheroma. We examined cases of retroperitoneal fibrosis and aortic aneurysms in order to quantify the types of heavy and light chains in the plasma cells. A mean of 44% of the plasma cells contained IgA and 52% contained lambda light chain. These results provide further evidence of the pathological relationship between retroperitoneal fibrosis and Riedel's thyroiditis. It is suggested that a cross-reaction between antigens in mucosal surfaces and in the thyroid or retroperitoneum may be implicated, possibly involving vessel walls. Of the total plasma cells in the wall of the aortic aneurysms 24% contained IgA and 40% lambda, although there was a significant trend towards a higher proportion of IgA with increasing thickness of the wall. No definite support for a relationship between atheroma and retroperitoneal fibrosis is provided by this study.