Allergic proctitis, a clinical and immunopathological entity

Intraepithelial lymphocyte eotaxin-2 expression and perineural mast cell degranulation differentiate allergic/eosinophilic colitis from classic IBD

OBJECTIVES

Allergic colitis shows overlap with classic inflammatory bowel disease (IBD). Clinically, allergic colitis is associated with dysmotility and abdominal pain, and mucosal eosinophilia is characteristic. We thus aimed to characterise mucosal changes in children with allergic colitis compared with normal tissue and classic IBD, focusing on potential interaction between eosinophils and mast cells with enteric neurones.

METHODS

A total of 15 children with allergic colitis, 10 with Crohn disease (CD), 10 with ulcerative colitis (UC), and 10 histologically normal controls were studied. Mucosal biopsies were stained for CD3 T cells, Ki-67, eotaxin-1, and eotaxin-2. Eotaxin-2, IgE, and tryptase were localised compared with mucosal nerves, using neuronal markers neurofilament protein, neuron-specific enolase, and nerve growth factor receptor.

RESULTS

Overall inflammation was greater in patients with CD and UC than in patients with allergic colitis. CD3 T-cell density was increased in patients with allergic colitis, similar to that in patients with CD but lower than in patients with UC, whereas eosinophil density was higher than in all other groups. Eotaxin-1 and -2 were localised to basolateral crypt epithelium in all specimens, with eotaxin-1+ lamina propria cells found in all of the colitis groups. Eotaxin-2+ intraepithelial lymphocyte (IEL) density was significantly higher in allergic colitis specimens than in all other groups. Mast cell degranulation was strikingly increased in patients with allergic colitis (12/15) compared with that in patients with UC (1/10) and CD (0/1). Tryptase and IgE colocalised on enteric neurons in patients with allergic colitis but rarely in patients with IBD.

CONCLUSIONS

Eotaxin-2+ IELs may contribute to the periepithelial eosinophil accumulation characteristic of allergic colitis. The colocalisation of IgE and tryptase with mucosal enteric nerves is likely to promote the dysmotility and visceral hyperalgesia classically seen in allergic gastrointestinal inflammation.

Local disodium cromoglycate is ineffective in ulcerative proctosigmoiditis

Conflicting results have emerged from studies using oral and rectal disodium cromoglycate (DSCG) in inflammatory bowel disease. In the present double-blind study, 43 patients with active ulcerative proctosigmoiditis received either placebo (n = 22) or 600 mg DSCG (n = 21) rectally as enemas for eight weeks. Assessment was made from clinical investigations, endoscopy, laboratory tests, biopsies, and diary cards. No statistically significant differences in bowel frequency, rectal bleeding, general well-being, abdominal pain, and severity and extent of the disease were found between the groups during the study. There was no significant change in the histologic parameters. No side-effect was encountered. It is concluded that DSCG did not improve symptoms or inflammatory changes in ulcerative proctosigmoiditis.

Combination therapy using fexofenadine, disodium cromoglycate, and a hypoallergenic amino acid-based formula induced remission in a patient with steroid-dependent, chronically active ulcerative colitis

Corticosteroids and 5-aminosalicylic acid are the primary standard therapy for inflammatory bowel disease. Recent immunologic data implicate an involvement of mast cell activation followed by increased histamine secretion and elevated tissue concentrations of histamine in the pathogenesis of ulcerative colitis. In the present case, the clinical course of a 35-year-old man with steroid-dependent chronic active ulcerative colitis, who did not respond to high-dose steroids, antibiotics, or azathioprine during 3 years, is reported. Clinical disease activity and established serological markers were recorded during 6 weeks of unsuccessful therapy and during the next 6 weeks, as a new nonsedative antihistaminergic drug, a mast cell stabilizer, and an hypoallergenic diet were implemented in addition to conventional therapy. Induction of remission was achieved within 2 weeks after treatment with fexofenadine, disodium cromoglycate, and an amino acid-based formula. Clinical disease activity, stool frequency, leukocytes, c-reactive protein, and orosomucoid levels in serum decreased rapidly. Daily steroid administration could be gradually reduced along with 6 weeks of this treatment. This report suggests that histamine and mast cell activity may be important pathophysiological factors responsible for persistent clinical and mucosal inflammatory activity in ulcerative colitis despite the use of steroids. In ulcerative colitis, patients unresponsive to conventional treatment, therapeutic considerations should also include an antiallergic approach when further signs of atopy or intestinal hypersensitivity are present.

Evaluation of mucosal eosinophils in the pediatric colon

To evaluate the clinical significance of colonic eosinophilia, we conducted a retrospective study of all children older than 1 year evaluated at Children's Hospital of Pittsburgh from January 1999 to June 2001 with a description of colonic eosinophilia in the pathology report. Medical records were reviewed. Diagnoses were confirmed by contacting the patients. Histological slides (H&E) were reviewed by an investigator blind to the patients' data. Biopsies were grouped according to the site they were taken from and then screened at low power for areas of maximal eosinophilia for further quantitative analysis. Results of manual counts were validated by image analysis using Metaphor Image Analysis Software. Sixty-nine children with colonic eosinophilia were identified (36 male; mean age, 135.2 +/- 55.4 months). Their final diagnoses were inflammatory bowel disease in 32% (group A), irritable bowel syndrome in 33% (group B), food allergies in 10% (group C), and other diagnoses in 25% (group D). The maximal eosinophil count per crypt area was significantly (P < 0.05) higher in group A vs groups B, C, and D (34.8 +/- 17.1 vs 21.3 +/- 8.8, 25.4 +/- 16.7, and 24.2 +/- 9.7, respectively). The total cellularity of the lamina propria was considered high only in group A (P < 0.05 vs groups B and C). A mostly equal vertical distribution of eosinophils throughout the lamina propria was found significantly more frequently in group A vs groups C (P = 0.04) and D (P = 0.007). We conclude that children with inflammatory bowel disease have an equal distribution of eosinophils throughout the lamina propria, with intraepithelial and intracryptal eosinophils and with a higher overall total cellularity. In irritable bowel syndrome and patients with a variety of other diagnoses, including allergies, the distribution is mostly superficial, with a lower total cellularity.

Prevalence of adverse reactions to food in patients with gastrointestinal disease

The role of allergic reactions in the pathogenesis of inflammatory bowel disease and irritable bowel syndrome has been disputed. This study aimed to determine the prevalence of adverse reactions to food in patients with gastrointestinal disease. A total of 375 adult patients of a gastroenterologic outpatient clinic were examined by history, skin tests, measurements of laboratory parameters, and intestinal provocation with food allergens by colonoscopy. Some 32% complained of adverse reactions to food as a cause of their abdominal symptoms. In 14.4%, the diagnosis of intestinal food allergy could be suspected according to several criteria such as elevated total IgE, specific IgE against food antigens, eosinophilia, responsiveness to cromoglycate, and clinical signs of atopic disease. In 3.2%, the diagnosis could be confirmed by endoscopic allergen provocation and/or elimination diet and rechallenge. In conclusion, the data suggest that allergic reactions to food antigens may be a causative factor in a subgroup of patients with inflammatory and functional gastrointestinal disease.

Chronic constipation as a symptom of cow milk allergy

Twenty-seven consecutive infants (mean age, 20.6 months) with chronic "idiopathic" constipation were studied to investigate the possible relation between constipation and cow milk protein allergy (CMPA). The infants were initially observed on an unrestricted diet, and the number of stools per day was recorded. Subsequently the infants were put on a diet free of cow milk protein (CMP) for two periods of 1 month each, separated by two challenges with CMP. During the CMP-free diet, there was a resolution of symptoms in 21 patients; during the two consecutive challenges, constipation reappeared within 48 to 72 hours. In another six patients the CMP-free diet did not lead to improvement of constipation. Only four of the patients who improved on the CMP-free diet had concomitant symptoms of suspected CMPA, but a medical history of CMPA was found in 15 of the 21 patients cured and in only one of the six patients whose condition had not improved (p < 0.05); in addition, in 15 of the 21 cured patients, results of one or more laboratory tests (specific IgE, IgG, anti-beta-lactoglobulin, circulating eosinophils) were positive at the time of diagnosis, indicating hypersensitivity, compared with one of the six patients whose condition did not improve (p < 0.05). The endoscopic and histologic findings at the time of diagnosis showed proctitis with monocytic infiltration in two patients cured with the CMP-free diet; after 1 month on this diet, they were completely normal. We conclude that constipation in infants may have an allergic pathogenesis.

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.

Interpretation of large intestinal mucosal biopsy specimens

The development of flexible endoscopes has led to a great increase in the examination and mucosal biopsy evaluation of all portions of the large intestine and rectum. Examinations are now performed not only for the determination of diagnosis but also for the monitoring of the course of a wide variety of conditions and for the early detection of complications. This review concentrates on the uses and interpretations of such biopsies in a large number of inflammatory conditions, with special emphasis on the correlations with clinical and functional features. Illustrated are examples of infections, idiopathic inflammatory bowel disease (IBD), vascular disorders, motor and mechanical conditions, toxic and physical reactions, and other inflammatory conditions. Mucosal biopsy specimens also are obtained to identify dysplasia and to evaluate mass lesions, and these subjects are well covered in other articles within this symposium. In patients with chronic disorders multiple examinations are now expected to follow the course of the disease and to detect and correct any complications at an early stage. The exact reasons for the endoscopy and relevant clinical data are essential for the optimal analysis of these mucosal biopsy specimens.

Allergic proctocolitis in infants: a prospective clinicopathologic biopsy study

Allergic proctocolitis is a major cause of rectal bleeding in infants, but its clinical features and laboratory results are often nonspecific. Our previous retrospective study demonstrated that large numbers of eosinophils in colonic mucosal biopsy specimens were highly associated with cases of allergic proctocolitis. Therefore, we prospectively examined 60 colonic mucosal biopsy specimens from the same sites (4, 8, and 12 cm from the anal verge) in 20 infants with clinically confirmed allergic proctocolitis to validate this morphologic feature, to characterize its distribution, and to correlate these data with the clinical information. The patients (age range, 4 to 304 days) were fed breast milk or a variety of formulas and all presented with rectal bleeding. Sigmoidoscopic examination was abnormal in 19 cases, typically characterized by focal areas of mucosal erythema. The major histologic finding was a strikingly focal increase in the number of eosinophils in all mucosal compartments, with a predilection to aggregate in close association with lymphoid nodules. Eosinophilic infiltration varied not only between biopsies at different sites, but also within individual biopsy specimens. Only 12 of 20 patients (60%) had all three of their biopsy specimens categorized as abnormal; in the remainder, only one (four patients) or two (four patients) of the three biopsy specimens were abnormal. The average number of eosinophils per high-power field of lamina propria for all cases was 15.6. No significant correlation was identified between the number of eosinophils in the mucosa and the patient's age, length of illness, endoscopic appearance, or type of inciting formula. In summary, eosinophils appear to be an excellent marker for infantile allergic proctocolitis. Given the focal distribution of the eosinophils, multiple mucosal biopsy specimens should be obtained and several levels of each examined to confirm the diagnosis.

Short-chain fatty acid enemas: a cost-effective alternative in the treatment of nonspecific proctosigmoiditis

The purpose of this study was to perform a randomized, prospective comparison of corticosteroid enemas (CS--100 mg of hydrocortisone/60 cc P.R. q.h.s.; n = 12), mesalamine enemas (5-ASA--4 g/60 cc P.R. q.h.s.; n = 19), and short-chain fatty acid enemas (SCFA--60 cc P.R. b.i.d.; n = 14) for the treatment of proctosigmoiditis. Patients presenting to the Ferguson Clinic with the diagnosis of idiopathic proctosigmoiditis were evaluated for age, sex, prior history of proctitis, duration of symptoms prior to presentation, endoscopic scoring, and mucosal biopsies. Clinical evaluation was performed at two-week intervals for six weeks, with repeat biopsies taken at six weeks. There was no significant difference with respect to age, male/female ratio, past history of proctosigmoiditis, length of colorectum involved at the time of initial presentation, symptom resolution, and endoscopic and histologic improvement among the three treatment groups. Recovery occurred in a similar proportion in each of the three groups: CS, 10/12; 5-ASA, 17/19; and SCFA, 12/14. The cost of six weeks of treatment was: CS, $71.82; 5-ASA, $347.28; and SCFA, $31.50. This study indicates that SCFA enemas are equally efficacious to CS or 5-ASA enemas for the treatment of proctosigmoiditis at a significant cost savings.

Nerve remodelling during intestinal inflammation

The intestinal mucosa contains a dense nerve network and many inflammatory cells, and these may interact through the exchange of regulatory molecules. Evidence suggests that intestinal mucosal mast cells are innervated, and it is known that the density of this cell type changes significantly in nematode-infected rats. Recent data indicates that rat jejunal mucosal nerves remodel after Nippostrongylus brasiliensis infection, with degenerative and regenerative phases during the acute and recovery stages of inflammation. Seven weeks postinfection there is a net increase in the density and number per villus of mucosal nerves. These changes suggest that mucosal nerves exhibit structural plasticity in inflamed tissues, which must impact on interactions between the enteric nervous system and other mucosal elements in disease.

Differential diagnosis of inflammatory bowel disease. A comparison of various diagnostic classifications

Fifty consecutive patients with inflammatory bowel disease of the colon who presented at the University Hospital Rotterdam/Dijkzigt were assessed by four methods: clinical diagnosis, criteria defined by Lennard-Jones and by the Organisation Mondiale de Gastroenterologie (O.M.G.E.) scoring systems, and histologic slide review. All cases were classified into three diagnostic groups: established Crohn's disease (CD), indeterminate colitis, or definite ulcerative colitis (UC). The classifications were compared by kappa analysis. Eighteen of the 50 patients were classified as having established CD by the O.M.G.E. scoring system and Lennard-Jones criteria; 17 were so classified by clinicians, and only 8 by histologic slide review. The agreement among clinician's diagnosis, Lennard-Jones criteria, and the O.M.G.E. scoring system was good (Fleiss-Cohen-weighted kappa; p less than 0.001). Agreement among histology, Lennard-Jones criteria, and the O.M.G.E scoring system was less good (p less than 0.05) and not significantly associated with clinical diagnosis. Histology was less prone to diagnose established CD or established UC and more likely to diagnose indeterminate colitis. This study has shown that the systems of disease definition set out by Lennard-Jones and the O.M.G.E. are comparable and agree well with each other and clinicians's diagnosis, but biopsy specimens have a limited diagnostic value in disease differentiation in inflammatory bowel disease.

Ulcerative proctitis in central Sweden 1965-1983. A population-based epidemiological study

Ulcerative proctitis has by tradition been regarded as a subgroup of ulcerative colitis. Population-based epidemiological studies of ulcerative proctitis are, however, virtually nonexistent. In an epidemiological study of inflammatory bowel disease in the Uppsala Health Care Region, 1065 cases of ulcerative proctitis were diagnosed from 1965 through 1983. Males predominated, with the male to female ratio 1.4:1. Annual incidence rates were higher in urban than in rural areas. The annual incidence rates increased threefold from 2.8 per 10(5) to 6.6 per 10(5) during the period, affecting all age groups over 14 years of age, in both urban and rural areas and in both sexes. Differences in temporal trends and certain other epidemiological characteristics between ulcerative proctitis and extensive ulcerative colitis suggest that ulcerative proctitis is a specific disease whose etiology differs from that of extensive ulcerative colitis.

Prevalence of atopy is unrelated to presence of inflammatory bowel disease

The prevalence of atopy (assessed by prick testing and serum IgE measurement), and of symptoms associated with atopy, has been defined in 122 patients with inflammatory bowel disease (IBD) and 103 age-matched controls. History analysis for atopic symptoms, and serum IgE levels, showed no differences between controls and IBD patients, or IBD subgroups (Crohn's disease, ulcerative colitis, ulcerative proctitis). Both in controls and in IBD patients, the prevalence of positive skin tests was higher in young people (aged less than 30) than in others; taking account of age distribution within the groups, there were no differences between controls and IBD patients, or subgroups, in the prevalence of positive skin tests. Our finding do not support the hypothesis that reaginic hypersensitivity plays a significant role in the pathogenesis of IBD.

Lymphoid follicular proctitis. A condition different from ulcerative proctitis?

A heterogeneous group is formed by patients presenting with clinical features suggestive of inflammatory bowel disease limited to the rectum and whose rectal biopsies show lymphoid follicular hyperplasia of the mucosa. All these cases are traditionally considered as one variant of chronic ulcerative colitis, so-called ulcerative proctitis. Twenty such cases were critically assessed on clinical, endoscopic, and histologic grounds, as well as on response to treatment and follow-up data. While 11 patients showed clinicopathologic features consistent with typical chronic ulcerative colitis, the other nine patients appeared to form a different group, for which the term "lymphoid follicular proctitis" seemed justified. Lymphoid follicular proctitis was, overall, characterized by rectal bleeding, a congested and granular mucosa without ulceration, abnormal and coalescing hyperplastic lymphoid follicles without acute inflammation, and failure to respond to local steroid therapy. The nature of lymphoid follicular proctitis is uncertain at present but seems unrelated to chronic ulcerative colitis.

Epidemiology of proctocolitis in the region of Leiden, The Netherlands. A population study from 1979 to 1983

An epidemiologic study of proctocolitis in the Leiden Health Care Region was conducted between 1979 and 1983. One hundred and seven cases were diagnosed before 1979 and 150 between 1979 and 1983. Most of the patients had proctocolitis (42%), and only 11% had pancolitis. The incidence was 6.8/10(5)/year and was similar in men and women. There was no specific age group at additional risk of developing the disease. The prevalence was 58.4/10(5). Patients with proctocolitis tended to live in country or city areas; people living in dormitory suburbs were at a reduced risk (chi-square test, p less than 0.001). However, there was a significant difference in incidence between Leiden (10.8/10(5)/year) and Alphen (4.1/10(5)/year) (corrected chi-square = 7.3; p less than 0.001). This was also true for the prevalence in these two cities. The prevalence of the disease in migrants (85.3/10(5)) was not significantly different from that in the indigenous population (58/10(5)).

Coeliac proctitis

An increased association of ulcerative colitis and coeliac disease has been reported, as have the results of several small-bowel biopsy studies in ulcerative colitis. Forty-two patients from a population of 438 patients with coeliac disease had rectal biopsies. Fourteen of these showed inflammation of various degrees of severity, including three compatible with a diagnosis of ulcerative colitis. The presenting complaint in 34 of these patients was diarrhoea or steatorrhoea. Twenty-seven patients had coeliac disease diagnosed at the same time or after their rectal biopsy. The other 15 were previously diagnosed coeliacs. Twelve of the 14 patients with abnormal rectal biopsy specimens were known to have subtotal/total villous atrophy at the time of rectal biopsy. Proctitis as seen in these coeliac patients had no unique features to differentiate it from proctitis caused by other disorders. The diarrhoea/steatorrhoea stopped in all patients on commencement of a gluten-free diet, except in those with ulcerative colitis. Proctitis is common in patients with coeliac disease presenting with diarrhoea/steatorrhoea. This study supports the finding of an increased association of coeliac disease and ulcerative colitis and is, to our knowledge, the first rectal biopsy study of a coeliac population.

Spirochaetosis of the human rectum associated with an intraepithelial mast cell and IgE plasma cell response

In two patients presenting with mild intestinal symptoms, rectal spirochaetosis was the only morphological abnormality diagnosed by light microscopy. A re-evaluation of the morphological changes using electron microscopy and immunohistochemistry showed certain unusual features: the microorganisms were observed within epithelial cells and in subepithelial macrophages; there were numerous partially degranulated intraepithelial mast cells; and there was a marked increase in the proportion of IgE plasma cells within the lamina propria. Mucosal penetration by the organisms may be responsible for the unusual immune response. In one patient, treatment with antibiotics eliminated the spirochaetes and resulted in a clinical improvement. Spirochaetes should not always be considered as harmless commensals in the colon.

Food allergy and intolerance

This article focuses on intolerance to food proteins, discussing the definition and history of food intolerance, the basics of gastrointestinal mucosal immunity, specific food antigens, pathogenesis, clinical manifestations, as well as diagnosis, therapy, and prevention.

Forms of colitis--a review of recent developments

Recent advances in the accessibility of the bowel and in techniques for the study of colonic pathology have resulted in descriptions of several forms of colitis which were previously unrecognized and in elucidation of the etiology of previously described but poorly understood entities. Present knowledge of antibiotic-associated colitis, colitis indeterminate, acute self-limited colitis, collagenous colitis and the colitis of food allergy is reviewed.

Immunology of inflammatory bowel disease

Although the aetiology of ulcerative colitis and Crohn's disease remain unknown, immunological effector mechanisms become activated within the inflamed mucosa and may be responsible for the pathogenesis of chronic disease. There is an increased production of immunoglobulin within the mucosa, some of which has specificity for bacterial antigens, and complement activation occurs during exacerbation of the disease. Lymphocytes isolated from peripheral blood, or from the intestinal mucosa, are cytotoxic to colonic epithelial cells in vitro; a reaction which can be modulated by serum factors and bacterial antigens. Within the mucosa, there are increased populations of T lymphocytes although there is no change in the ratio of helper- to suppressor-cells as defined by phenotype. Studies of immunoregulatory control have shown that there may be alterations in the modulation of the local immune response, especially during active disease, although it is not clear whether these changes are primary or merely secondary to inflammation. It is posulated that many of the humoral and cellular responses to gut-associated antigens occur as a result of increased antigen absorption, increased presentation of antigen to the immune system due to the expression of Class II antigens by the inflamed epithelium and altered immuno-regulatory control.

Correlation of histopathologic evidence of disease activity with the presence of immunoglobulin-containing cells in the colons of patients with inflammatory bowel disease

Immunofluorescence of formalin-fixed, paraffin-embedded tissues was performed to study the plasma cell population in 114 colonic specimens from 58 patients. Correlation of the histopathologic stage of disease activity with the isotypes and numbers of immunoglobulin-containing cells in the lamina propria demonstrated highly significant (P less than 0.001) increases in the mean numbers of IgG- (18-fold), IgA- (twofold) and IgM- (sixfold) containing cells in specimens from patients with active inflammatory bowel disease as compared with control specimens. Increased numbers of immunoglobulin-containing cells were uncommon in inactive inflammatory bowel disease and in reactive mucosa. No deposition of immunoglobulin-containing immune complexes was found at any stage of disease activity. These findings suggest that immune complex-mediated damage does not play a major role in the epithelial damage in inflammatory bowel disease. In future studies, it will be of importance to determine whether the antibody from immunoglobulin-containing cells seen in patients with inflammatory bowel disease can effect damage via an antibody-dependent cell-mediated cytotoxicity mechanism.

Increased numbers of IgE containing cells in gastric and duodenal biopsies. An expression of food allergy secondary to chronic inflammation?

Gastric and duodenal biopsies from 2543 patients with abdominal complaints were sent to the Department of Pathology of the Stichting Samenwerking Delftse Ziekenhuizen in 1980 and 1981 and screened for plasma cells containing IgE using an indirect immunoperoxidase technique. Increased numbers of IgE containing cells were found in 2.6% of the patients. These patients all suffered from a variety of chronic non-specific inflammatory disorders of the upper gastrointestinal tract. No specific clinical, endoscopical, or histological picture could be found. The results suggest that increased numbers of plasma cells containing IgE in biopsies from the upper gastrointestinal tract are an expression of IgE mediated type I allergy presumably to food constituents as a secondary complication of chronic non-specific gastric and duodenal inflammation in these patients.

Rectal mucosal plasma cells in inflammatory bowel disease

To achieve optimum staining and reproducible counts of plasma cells in paraffin embedded tissue with the immunoperoxidase technique we have found it essential to obtain a plateau count by titration of antisera for each specimen. This modification was used to study IgA, IgM, IgE, and IgG plasma cells in rectal biopsies from 20 controls, 20 patients with ulcerative proctocolitis, 20 with Crohn's colitis, 20 with non-specific proctitis, 15 with bacterial colitis, and seven with Crohn's disease but no apparent large bowel involvement. Counts were correlated with the characteristic histological features of inflammatory bowel disease. In controls the ratio of the mean counts for IgA, IgM, IgE, and IgG plasma cells was 8:3:3:1. All types of plasma cells were very significantly increased in the patients with ulcerative proctocolitis, Crohn's colitis, and non-specific proctitis and counts correlated with the severity of inflammation. There was no significant difference between the counts in these three groups. All counts tended to be higher in bacterial colitis than in controls, the difference being significant for IgA and IgE. When matched for severity of inflammation there was no significant difference between the counts in bacterial colitis and inflammatory bowel disease. The counts in patients with Crohn's disease but no large bowel involvement were not significantly different from controls. These results suggest that changes in plasma cell counts in inflammatory bowel disease are a non-specific response to mucosal damage, possible by a luminal irritant, and do not differentiate the type of inflammatory bowel disease.

Human intestinal mucosal mast cells: expanded population in untreated coeliac disease

Previous retrospective studies of intestinal mucosal mast cells in coeliac disease have given divergent results, and we have recently reported that inappropriate methodology could account for these discrepancies. In this prospective study, mucosal mast cell counts were performed in Carnoy fixed, peroral jejunal biopsy specimens from patients with coeliac disease, both untreated and treated with a gluten-free diet; and from controls (mainly irritable bowel syndrome). Mean mucosal mast cell count in 27 control subjects was 146/mm2, SD 29. Significantly higher values were obtained in untreated coeliac disease (mean 243, SD 41, p less than 0.001) returning to the normal range in coeliacs treated with a gluten-free diet with normal jejunal biopsy morphology. In seven patients mucosal mast cell counts were performed in multiple jejunal biopsies, and these showed that mucosal mast cell distribution was not patchy. There was no evidence of degranulation of intestinal mucosal mast cells under the conditions of routine biopsy (overnight fast). An increase in mucosal mast cells in untreated coeliac disease may be one explanation for the high number of IgE positive stained cells in the intestinal mucosa that has been reported by some authors.

The effect of disodium cromoglycate on rectal mucosal histamine release, eosinophil exudation and disease activity in active ulcerative colitis

Disodium cromoglycate has been reported to benefit some patients with active ulcerative colitis. We have investigated the effect of cromoglycate in high dose on rectal mucosal mast cell degranulation (assessed indirectly by measurement of mucosal histamine release, using in vivo rectal dialysis, and the eosinophil content of the rectal inflammatory exudate) and on disease activity in eight patients in relapse. Although cromoglycate (1600 mg by mouth daily for 2 weeks) did not affect histamine release, it reduced (P less than 0.05) the eosinophil content of the exudate towards normal. Stool frequency also fell (P less than 0.05) but other aspects of bowel habit, sigmoidoscopic appearance, rectal mucosal potential difference and electrolyte transport were unaltered. Pre-treatment values of histamine release and eosinophil exudation could not be used to predict the response to cromoglycate. The reduction in eosinophil exudation produced by the drug could be due to inhibition of mast cell release of chemotactic factors other than histamine; the therapeutic effect of cromoglycate was unimpressive.