Autoimmune Enteropathy and Colitis: Is There a Generalised Autoimmune Gut Disorder? Gut: First Published As 10.1136/Gut.32.1.36 on 1 January 1991

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36 Gut, 1991, 32, 36-42 Autoimmune enteropathy and colitis: is there a generalised autoimmune gut disorder? Gut: first published as 10.1136/gut.32.1.36 on 1 January 1991. Downloaded from

S M Hill, P J Milla, G F Bottazzo, R Mirakian

Abstract disease and jejunal crypts in coeliac disease.8'-0 Children with protracted diarrhoea, circulat- All of these epithelia are known to be physiologi- ing enterocyte autoantibodies, and an entero- cally devoid of class II molecules. pathy showing features of inappropriate HLA Experimental evidence has shown, in the molecule expression on the jejunal crypt context of autoimmunity, that when epithelial epithelium, often present with persistent blood cells acquire class II products they are able to act and mucus in their stools. Eight children with as accessory antigen presenting cells, and so autoimmune enteropathy were investigated for become capable of presenting autoantigens to the presence ofassociated colonic disease. Six CD4 activated T lymphocytes in a major histo- children with protracted diarrhoea, no circu- compatibility complex restricted fashion. " It has lating autoantibodies, and an enteropathy (in been suggested that this phenomenon may play a five of them) undergoing colonoscopy were relevant role in the final autodestruction of used as control subjects. In all eight patients, epithelial cells.'2 There are indications that a but not in the control subjects, there was similar mechanism could operate in inflam- macroscopic and microscopic evidence of an matory bowel disease.6 accompanying colitis of variable severity, thus In classical enteropathies such as coeliac indicating that a more generalised intestinal disease the mucosal abnormality is generally disorder was present, which might affect the confined to the small intestine and the colonic whole intestine. Aberrant expression of DR mucosa is spared. In children with severe pro- molecules on the colonic surface and crypt tracted diarrhoea and autoimmune enteropathy, epithelium was also detected. Autoimmunity however, it has been repeatedly observed that may play a role in the colitis. the diarrhoea responds only partially to dietary treatment and that blood and mucus can be present in the stools. These latter findings sug- A proportion of children with protracted gest that an inflammatory process affecting the http://gut.bmj.com/ diarrhoea associated with an enteropathy have a colon could be associated with the enteropathy strong family or personal history or both, of and that a more generalised intestinal disorder autoimmune diseases, organ and non-organ occurs in these patients. specific autoantibodies, and persistent circulat- The aim of this study, therefore, was to ing enterocyte autoantibodies, thus suggesting ascertain the possible presence of a colitis in that autoimmunity may play a role in the entero- these children and, if confirmed, to define better pathy.' We have previously reported that the the histological and immunological characteris- on September 30, 2021 by guest. Protected copyright. enterocyte autoantibodies seem to be virtually tics, with particular reference to features of specific to this condition in that they were not immune activation such as inappropriate class II detected in sera from children with coeliac molecule expression on the epithelium, as disease and were present only in lower titres (less already detected in the small intestine. than 1/8) in 5% of patients with classic inflammatory bowel disease. Inappropriate expression of HLA class II molecules in the crypt epithe- Patients and methods lium of proximal small intestinal biopsy specimens obtained from affected children has been PATIENTS documented also.2 Major histocompatibility Eight children (seven boys and one girl) with complex (MHC) class II products are usually protracted diarrhoea of more than 2 weeks Department ofChild restricted to the cells of the immune system and duration (range 2 months to 2 years) and aged 5 Health, Institute of Child play a role in antigen presentation and induction months to 2 years on presentation, were found to Health, London of the S Hill immune response. Mature enterocytes of have circulating small intestinal enterocyte auto- P J Milla the small intestine (but not immature entero- antibodies detected by indirect immunofluo- cytes)3 4 represent an exception in that they rescence on at least two occasions. In six of the Department of express these molecules physiologically. It has eight there was a titre of 1/8-1/128. They under- Immunology, The University College and been suggested that the function ofMHC class II went peroral jejunal biopsy (Watson Paediatric Middlesex School of molecules in the small intestine is related to the Capsule) and were found to have: (a) an entero- Medicine, London maintenance of oral tolerance.' I pathy with a variable degree of villous atrophy G F Bottazzo R Mirakian The phenomenon of aberrant MHC products (Table I), lymphomononuclear infiltration of the the Correspondence to: has previously been observed in epithelium lamina propria, but no increase in the number of Dr R Mirakian, Department of of diseased tissue obtained from patients with intraepithelial lymphocytes and in six of eight Immunology, The University College and Middlesex School classic autoimmune diseases, such as insulin crypt hyperplasia; (b) aberrant class II molecule of Medicine, Arthur Stanley dependent diabetes mellitus and autoimmune expression detected in all jejunal biopsy speci- House, 40-50 Tottenham Street, London WIP 9PG. thyroid disorders.7 It has also been repeatedly mens in the crypt epithelium. Accepted for publication described in the colonic mucosal epithelium Clinical details are shown in Table II. Patients 19 February 1990 from patients affected by inflammatory bowel 1, 2, 3, and 7 have been described previously. Autoimmune enteropathy and colitis: is there a generalised autoimmune gut disorder? 37

TABLE I Histological appearances oflarge and small treated with parenteral nutrition from 2 weeks of intestinal biopsy specimensfrom autoimmune patients on was not on this presentation and during relapses age as he gaining weight and treatment had satisfactory weight gain. Plasma Colonic histology* Jejunal histology albumin was below 30 g/l in patients 1 (23 g/l), 3 Gut: first published as 10.1136/gut.32.1.36 on 1 January 1991. Downloaded from Patient and age and age (13 g/l), 6 (27 g/l), and 7 (17 g/l) on presentation. 1 6 months: grade 2 5 months: SSVA Patient 3 had concomitant nephrotic syndrome. 10 months: PVA 2 1 year: grade 3 8 months: SVA Seven patients had other circulating autoanti- 1 year: SVA bodies and three of these had autoimmune 3 years: grade 2 3 years: normal an 5 years: grade 2 disorders (Table II). Patient 3 developed 3 2 years: patchy grade 1 2 years: patchy PVA interstitial nephropathy with tubular membrane 4 2 years: grade 1 2 years: severe PVA 5 9 months: grade 1 9 months: normal autoantibodies which resulted in end stage renal 19 months: grade 2 19 months: PVA failure, and he underwent renal transplant. 6 7 months: grade 1 7 months: PVA 7 5 months: grade 1 16 months: patchy PVA Patient 4 had a Coomb's positive haemolytic 8 2 years: grade 1 2 years: PVA anaemia. Patient 7 presented at 3 months of age with psychomotor retardation and he was found *See text for grading. SSVA=severe, subtotal villous atrophy; PVA=partial villous atrophy; SVA=subtotal villous atrophy. to be hypothyroid with thyroglobulin and microsomal antibodies (at the same time as he pre- All eight patients presented with severe pro- sented with diarrhoea). Patient 6 had biliary tracted diarrhoea which had started between 2 hypoplasia which was possibly autoimmune in weeks and 1 year of age. They were all anorexic nature in that bile duct autoantibodies were and lethargic. The weight was below the third detected. centile for age in seven children, but one (patient Six children also had a family history of 6) had been on parenteral nutrition from 2 weeks possible autoimmune disease. Patients 1, 6, and of age and his weight was in the normal range. 8 had first degree relatives with histories of The length of six children was normal, but the protracted diarrhoea, and this was most severe in height oftwo ofthose who presented aged 2 years patient 8 who had four siblings who had died of was below the third centile. The erythrocyte diarrhoeal disorders. The brother of patient 2 sedimentation rate was raised in the three in had insulin dependent diabetes, the father of whom it was measured on presentation. In only patient 7 had vitiligo, and the mother ofpatient 5 one patient (patient 7) was-there a personal and was thyrotoxic. family history of initial acute, possibly infec- All children were initially treated with an tious, diarrhoea. He presented first with vomit- oligoantigenic diet which consisted of a cow's ing; diarrhoea ensued within 48 hours and his milk, egg, and gluten free regime. Comminuted father suffered a similar illness. No stool samples chicken meat (Cow and Gate) was used as cow's http://gut.bmj.com/ were taken until several days after the onset of milk substitute in five patients; Pregestimil, a diarrhoea, when the child's stool was examined casein hydrolysate (Mead Johnson, UK) to two; for viral and bacterial pathogens, but none were and Pepdite, a peptide formulation (Scientific detected. Three patients (patients 1, 4, and 5) Hospital Supplies Ltd, UK) in one. Despite had life threatening watery diarrhoea which was improvement in the symptoms while on the diet, secretory in origin (stool sodium 83-116 mmol/l) a variable degree of diarrhoea persisted in all to 1 eight patients. In four of the eight there was on presentation hospital. Patient passed up on September 30, 2021 by guest. Protected copyright. to 2 1 ofstool per 24 hours when he weighed 5 kg blood and mucus in their stool. In all patients at 7 to 8 months of age. Patients 1, 4, and 6 had stool culture and electron microscopy were nega- fat globules detected in stool but faecal fat con- tive. Total colonoscopy was performed in all tent was not formally measured in any child. eight patients with an Olympus PCF10 colono- Patient 5 had a gastrochisis and required a small scope. In patients 5 and 7, colonoscopy preceded intestinal resection soon after birth. He was jejunal biopsy. At least two biopsy specimens

TABLEII Clinicalfeatures andfamily history ofpatients with autoimmune enteropathy (EcAb+) Other Family history of Gut autoantibody Age at Age at autoimmune gastrointestinall titre (EcAb). Patient presentation Sex onset diseases autoimmune diseases Other autoantibodies 1 5 mths M 3 mths - Uncle: protracted EcAb 1/128 diarrhoea of infancy BB +ve 2 8 mths F 5 mths - Grandmother: EcAb 1/64 thyrotoxicosis PCA weak+ve Brother: IDDM 3 2 yrs M 1 yr Interstitial - EcAb 1/64 nephropathy PCA 1/80, ANA 1/1280 Chronic hepatitis DNA 1/320, TBM 1/80 4 2 yrs M 4 mths Haemolytic - EcAb+ve Anaemia Coomb's+ve 5 9 mths M 2 wks Mother: EcAb 1/8 thyrotoxicosis TBM 1/40 6 7 mths M 1 mth Biliary Siblings: protracted EcAb 1/8 hypoplasia diarrhoea and biliary Bile duct+ve hypoplasia AMA 1/20 7 5 mths M 3 mths Hypothyroidism Father: vitiligo EcAb 1/64 TgHa 1/5 000 McHa 1/1 600 SMA 1/10 8 2 yrs M 1 mth 4 siblings died from EcAb 1/8 diarrhoeal diseases

BB=brush border rat kidney antibodies; SMA=smooth muscle antibodies; TBM=tubular basement membrane antibodies; PCA=parietal cell antibodies; McHa=microsomal antibodies; ANA=antinuclear antibodies; DNA=native DNA antibodies; AMA=antimitochondrial antibodies; TgHa=thyroglobulin antibodies. 38 Hill, Milla, Bottazzo, Mirakian

were taken from the following regions of the each incubation the sections were washed with colon: caecum, ascending colon, transverse phosphate buffered saline for 10 minutes. The colon, descending colon, sigmoid colon, and slides were then mounted and the reading was

rectum in all patients. performed by two independent readers using a Gut: first published as 10.1136/gut.32.1.36 on 1 January 1991. Downloaded from All the children remained on a hypoallergenic Zeiss type III microscope. diet and treatment with salazopyrine (50 mg/kg! day) was given for colitis. In those in whom symptoms persisted, immunosuppressive treat- COLONIC BIOPSY SPECIMEN STUDIES ment was begun with prednisolone alone At least two separate specimens from adjacent (2 mg/kg/day, gradually reduced, when possible, areas of the caecum; ascending, transverse, to a maintenance dose 0 5 mg/kg, alternate descending, and sigmoid colon; and rectum were days) or in combination with azathioprine processed. One specimen from each area was (2 mg/kg/day) ifthe symptoms were still present. fixed in Bouin's solution and examined using a Further treatment with cyclophosphamide conventional haematoxylin and eosin stain, and (3 mg/kg/day) was given if no response to another was snap frozen for subsequent prednisolone and azathioprine was achieved. immunofluorescence studies. The response to treatment was measured clini- As with the immunological data, the inter- cally by observing stool consistency and output pretation of the histological results was per- and recording weight gain, and by endoscopy formed blind by two independent observers. and biopsy when indicated. The patient and control biopsy specimens were Detailed immunological studies included: pooled, coded, and examined in random order. total white cell count and differential, value of The histological appearance of the mucosa was serum immunoglobulins (Ig) and IgG sub- graded from 1 to 3 according to the severity of classes, absolute number and % ofT cell subsets, inflammation of the lamina propria using the T cell function (by passive haemagglutination following criteria: stimulation), neutrophil mobility and function, Grade 1: mild inflammatory infiltrate with no and measurement of the alternative complement other apparent pathological changes present in pathway activity (by yeast opsonisation). the surrounding tissue. Grade 2: moderate inflammatory infiltrate with patchy goblet cell depletion with or without CONTROLS minor crypt distortion. Six children were used as control subjects. Grade 3: heavy inflammatory infiltrate with Jejunal biopsy and colonoscopy were undertaken marked goblet cell depletion or crypt abscesses, only where both investigations were clinically or both, and crypt dysplasia. indicated. The control subjects comprised five Cryostat sections from snap frozen colonic http://gut.bmj.com/ girls and one boy, aged from 3 weeks to 10 years biopsy specimens were stained for HLA class I on presentation, all of whom had had diarrhoea molecules and class II subregion products for more than 2 weeks (range 3 weeks to 2 years). (HLA-DR, DP, DQ) using indirect immuno- Their serum was negative for enterocyte auto- fluorescence and the corresponding monoclonal antibodies or other known autoantibodies apart antibodies (Table III), as previously reported.2 from reticulin antibody in one. Stool culture, At least two different levels of the tissue block microscopy, and electron microscopy studies were examined. on September 30, 2021 by guest. Protected copyright. were also negative. They all underwent proximal Immunoperoxidase staining was performed small intestinal mucosal biopsy. In five the on sections from two patients and three control intestinal mucosa was abnormal. One child with subjects using monoclonal antibodies to CD3, reticulin antibodies had subtotal villous atrophy CD8, and CD4 lymphocyte subpopulations, and that resolved on a gluten free diet and a diagnosis positive intraepithelial lymphocytes were of possible coeliac disease was made. Three counted per 1000 epithelial cells. children with partial villous atrophy had idio- pathic protracted diarrhoea, and one child with a mucosal infiltration ofeosinophils had an eosino- Results philic gastroenteropathy. The child with histo- logically normal mucosa had congenital IMMUNOLOGY chloridorrhoea. An inappropriate class II expres- There were no severe immunodeficiencies. One sion was detected in the crypts of the patient child had no detectable serum IgA and four of with subtotal villous atrophy and two of those the six investigated had an abnormality ofat least with partial villous atrophy, but in the other one IgG subclass (Table IV). T cell subsets were three subjects this abnormality was not observed. abnormal in three patients (Table IV). Two children had reduced neutrophil mobility. One child (patient 2) had increased numbers of ANTIENTEROCYTE ANTIBODY ASSAY circulating activated cells (71% v an expected An indirect immunofluorescence method was 17% of DR+ cells). used to detect enterocyte autoantibodies using The results of HLA tissue typing are given in human blood group 0 duodenum, obtained Table IV. from patients undergoing Whipple's procedure.' Briefly, 4 ,um cryostat sections were incubated with undiluted patient's serum for 30 minutes at COLONOSCOPY room temperature. A subsequent incubation At colonoscopy, the colon was macroscopically with fluorescein isothiocyanate conjugated abnormal throughout its length in the eight rabbit antihuman IgG (DAKO) followed. After index patients, with loss of the normal vascular Autoimmune enteropathy and colitis: is there a generalised autoimmunegut disorder? 39

TABLE III Mouse monoclonal antibodies usedfor immunofluorescence study predominantly consisted of lymphocytes and plasma cells with scattered eosinophils and Clone Specificity Class Source neutrophils (Fig 2 (A) and (B)). In two patients Mid 3 HLA-DR IgG, G Guarnotta and B Lydyard II and III was Gut: first published as 10.1136/gut.32.1.36 on 1 January 1991. Downloaded from (non-polymorphic) (grade colitis) there patchy deple- DA6. 164 HLA-DR locus specific IgG, K Guy and V Van Heningen tion of goblet cells and, in one the microscopic TU22 HLA-DQ/locus IgG, A Ziegler findings were more severe; there was distortion B7/21 DP locus IgG, W and J Bodmer W6/32 HLA-A, B, C IgG2a W and J Bodmer of the crypt architecture and crypt abscesses P11 H4 Mouse thyroglobulin IgG1 G Guarnotta and P Lydyard were seen (grade III). (as control) UCHT, (CD3) Pan T IgG, P C L Beverly Different biopsy specimens from different UCHT4 (CD8) Cytotoxic-suppressor IgG1 P C L Beverly regions of the colon in individual patients Leu 3a (CD4) Helper/inducer IgG1 Becton-Dickinson showed only minor variations of not more than

TABLE IV Immunological profile in patients with autoimmune enteropathy Tcell subset ratios Patient Total IgG IgGI IgG2 IgG3 IgG4 CD4:CD8 HLA tissue typing 1 N N Undetectable N Undetectable 5:1 A1, 28; B8, 51; Cw7, 0 DR2, 3 (British) 2 N N 4 N N N A1,24;B39;Cw7,0 (58-174)* DR 6, 7 (British) 3 38 - - - - - A3, 26; B7, 49; Cw6, 7 (48-138) DR2, 5 (British) 4 N N N N N 1:1 5 N 256 32 106 40 N A1, 2; B44, w57 (333-724) (40-188) (14-5-36-5) (5-5-31-5) Cw4, 6; DR 4, 7 (British 6 N N 16 N 1 5 N A23,26: B35,49; (35-87) (4-8-17-8) Cw4, 7; DR 2, 3 (Arabic) 7 24 - - - N A3,23;B14,35 (25-108) (British) 8 N NN N N 1:2 - *Normal values for age are given in parenthesis; N-normal; -=not performed.

pattern (Fig 1 (A) and (B)), mucosal friability, one grade. No abnormalities were seen in the and frequent contact bleeding. In addition, in control colon specimens except in one subject three patients the mucosa showed patchy areas of where melanosis coli was detected. There was no erythema and in two others there was visible discordance in the histological findings between http://gut.bmj.com/ ulceration. In the six control children, the the two independent observers. colonic mucosa was endoscopically normal.

IN SITU IMMUNOLOGICAL STUDIES HISTOLOGY Morphological alterations were present in all HLA class I expression on colon epithelial cells

eight patients but varied from a diffuse mild In both patient and control biopsy specimens, on September 30, 2021 by guest. Protected copyright. colitis with only an increase in inflammatory cells the expression of HLA-A, B, C molecules was to a severe colitis with goblet cell depletion, crypt detected with approximately the same intensity. dysplasia, and crypt abscess formation. In no The staining pattern was not homogenous and cases were granuloma seen. In six children there areas of stronger reactivity in the crypt was a mild (grade I) colitis with an infiltration of epithelium could be seen compared with those of inflammatory cells in the lamina propria which the surface epithelial cells.

Figure 1: Macroscopic appearance ofthe colon at colonoscopy. (A) Mild colitis with loss ofthe normal vascular pattern and occasional areas of erythema. (B) More severe changes with marked erythema. 40 Hill, Milla, Bottazzo, Mirakian Gut: first published as 10.1136/gut.32.1.36 on 1 January 1991. Downloaded from

Figure 2: Histological appearance ofa typical example ofautoimmune colitis (grade 1). (A) Preservation of crypt architecture. Some irregularities of the surface epithelium and increased cellularity ofthe lamina propria. (Original magnification x 250.) (B) Increased cellularity due to infiltration ofmononuclear cells. (Original magnification x400.)

HLA class II expression on colonic epithelial cells HLA class II molecule expression was abnormal in all eight patients in all the colonic biopsy specimens examined. There was positive staining of the surface and crypt epithelium (Fig 3 (A)). HLA-DP and DQ product expression was normal - that is, absent on the surface and http://gut.bmj.com/ crypt epithelium. No HLA class II molecules could be observed on the surface and crypt epithelial cells of the control biopsies (Fig 3 (B)). The number of DR positive activated immuno- cytes in the lamina propria was proportional to the density of the lymphocytic infiltration. A similar staining intensity was present in both on September 30, 2021 by guest. Protected copyright. patients and cntrol subjects. Intraepithelial lymphocytes in colonic epithelium No increase in CD3+ intraepithelial lymphocytes was detected in either the patients' or the control subjects' colonic biopsy specimens (range 0-5-1 2 per 100 epithelial cells). CD8 positive intraepithelial lymphocyte counts ranged from 1N1 to 2 lymphocytes per 100 epithelial cells, and it was clear that a proportion ofCD8+ cells were also CD3+.

RESPONSE TO TREATMENT One child (patient 7) remained on an oligoantigenic diet alone, the diarrhoea resolved, and repeated colonoscopies were not clinically indicated. The other seven children required immunosuppressive treatment, initially with prednisolone alone. Patient 2 has relapsed when- ever this has been stopped. Total colonoscopy with multiple biopsy specimens has been performed three times and has shown moderately active non-specific colitis at times of relapse, two and four after She has -,.,,...... ; t years presentation. Figure 3: Colonic mucosa stained by indirect immunofluorescencefor HLA-DR expression. (A) remained on a low dose of oral prednisolone Aberrant expression ofHLA-DR by crypts in autoimmune colitis. (B) Normnal colon showing since. In four patients (1, 4, 5, and 8) the small positive staining ofcells in lamina propria and negative crypts. intestinal enteropathy was more severe than the Autoimmune enteropathy and colitis: is there a generalised autoimmune gut disorder? 41

colitis and they required more aggressive had an autoimmune enteropathy and another (in immunosuppresion for the enteropathy than for whom enterocyte autoantibodies were not the colitis. In patient 1 the secretory diarrhoea sought) had thyrotoxicosis. stopped only when azathioprine was given. It seems that the group of children presented Gut: first published as 10.1136/gut.32.1.36 on 1 January 1991. Downloaded from Patient 4 improved when cyclophosphamide was here with protracted diarrhoea of infancy, is given as well as azathioprine, but eventually died affected by an enterocolitic process and that the at the age of 4 years. In patient 5, the colitis severity ofthe enteropathy usually overrides that preceded the enteropathy. It initially responded ofthe colitis. The colitis, however, heightens the to prednisolone but recurred after a few months, severity of the diarrhoea by reducing the finally improving with the addition of azathio- 'salvage' Capacity of the colon and in addition is prine. Patients 3, 6, and 8 also responded to responsible for the presence ofblood and mucus. azathioprine. All children continued to take Whether both regions of the gut are simul- prednisolone and a restricted diet. Patient 3, taneously affected or one is affected before the however, later developed chronic renal failure other is usually not clear. It is, however, of and required a renal transplant and further interest that in an experimental animal model immunosuppressive treatment for this. Of the small bowel extracts injected into rats were able seven surviving children, six are now thriving to induce a colitis in the same animal, and the with their weight in the normal range and are antiserum obtained from the immunised rats growing at a normal rate. The seventh child gave an immunofluorescent reaction on the small (patient 8) has been lost to follow up. Patient 5 intestinal epithelia similar to that described in (who had a small intestinal resection) continues children with autoimmune protracted diar- to require his diet to be supplemented with rhoea and enterocyte autoantibodies.1' This parenteral nutrition. experimental evidence taken together with our clinical observations described here suggest a common pathogenetic process affecting both the Discussion small intestine and the colon. Our findings show that children with protracted In the present study, the inappropriate DR diarrhoea, circulating enterocyte autoanti- expression in the crypt epithelium and the bodies, and an enteropathy, who may also presence of various degrees of lymphocyte in- present with blood and mucus in their stools, filtration in the lamina propria of the colonic have histological evidence of an accompanying biopsy specimens of children affected with pro- colitis. These observations suggest the presence tracted diarrhoea, parallel similar observations of a novel generalised gut syndrome, affecting previously described in the crypt epithelium of

both the small intestine and the colonic mucosa, the jejunum2 and indicate that the same immuno- http://gut.bmj.com/ with common immunomorphological features. logical mechanism is possibly responsible for It seems that an autoimmune predisposition also both the enteropathy and the colonopathy. The occurs in these patients in that autoimmune detection ofan aberrant HLA class II expression disorders or other autoantibodies, or both, are in the small intestine and in colonic crypts is present in most. However, possibly because of reminiscent of a similar event already described the small number of patients investigated, HLA in gland epithelium obtained from patients with

tissue typing did not consistently document the classical autoimmune diseases.7 Thus, there is on September 30, 2021 by guest. Protected copyright. presence of haplotypes generally observed in the possibility that this phenomenon, which has autoimmune disease and there was not an already been shown to play an important role in obvious association with systemic immuno- initiating or maintaining the epithelial cell des- deficiency. truction in classical autoimmune diseases (via The existence of a clear 'generalised gut dis- autoantigen presentation to CD4+ 'activated' T order' affecting both the small intestine and the lymphocytes), could also be responsible for the colon is an unusual finding. With the exception enterocyte and colonocyte damage. of Crohn's disease, which may involve any part However, at least within the gut, the detection ofthe gastrointestinal tract, there have been only of inappropriate DR expression in the isolated reports describing the simultaneous in- epithelium is not always seen in a strict context of volvement of the small and large bowel. A colitis autoimmunity. It has clearly been described in has been found in a few adults who also have mucosa obtained from colon affected by car- coeliac disease, suggesting a possible association cinoma,'8 Crohn's disease, and ulcerative colitis,8 between the two clinical conditions.'3 Further- and in the crypts of small intestinal biopsy more, it is known that diffuse damage of both specimens from patients with coeliac disease.9 In small intestine and colon sometimes occurs in these diseases, no circulating enterocyte auto- subjects with scleroderma or other connective antibodies have been shown and the existence of tissue disorders.'4 In children, however, reports a clear autoimmune mechanism is still contro- concerning the existence of protracted entero- versial. Recently, however, a colonic tissue colitis have been even more scarce and so far have bound IgG has been specifically found in colonic not led to the recognition of a specific clinical biopsy specimens from patients with ulcerative entity. Colonic inflammation severe enough to colitis'920 and an antibody dependent cell cause rectal bleeding has been described in two mediated cytotoxicity to epithelial targets has children with coeliac disease."' In a more recent also been detected in the lymphocytes in the series, Sanderson et al'6 reported the presence of lamina propria of the colon of these patients but a microscopic colitis in 5% of children under- not of controls.2' Consequently, the possibility going colonoscopy for protracted diarrhoea. that autoimmune mechanisms may play a role in Four of the six patients had abnormal small inflammatory bowel disease still exists, although bowel morphology. Interestingly, one of these it is certainly far from being established. 42 Hill, Milla, Bottazzo, Mirakian

In our patients, the evidence that the inappro- 1 Mirakian R, Richardson A, Milla PJ, et al. Protracted diarrhoea of infancy: evidence in support ofan autoimmune priate class II expression in the colonic variant. BMJ 1986; 293: 1132-6. epithelium and the lymphocytic infiltration in 2 Mirakian R, Hill S, Richardson A, Milla PJ, Walker-Smith JA, Bottazzo GF. HLA product expression and lymphocyte the lamina propria are clearly due to an auto- subpopulation in jejunum biopsies of children with idio- Gut: first published as 10.1136/gut.32.1.36 on 1 January 1991. Downloaded from immune phenomenon is circumstantial, though pathic protracted diarrhoea and enterocyte autoantibodies. JAutoimmun 1988; 1:,263-77. the presence of circulating enterocyte autoanti- 3 Scott H, Solheim BG, Brandtzaeg P, Thorsby E. HLA-DR bodies points in this direction. Unlike circulat- like antigens in the epithelium ofthe human intestine. Scand J Immunol 1980; 12: 77-82. ing enterocyte autoantibodies, colonic anti- 4 Selby WS, Janossy G, Goldstein G, Jewell DP. T lymphocytes bodies could not be reproducibly detected in our in human intestinal mucosa: the distribution and relation- ship to MHC-derived antigens. Clin Exp Immunol 1981; 44: hands. In any case, there is considerable doubt 453-8. about their importance as their presence in 5 Bland PW, Warren LG. Antigen presentation by epithelial cells of the rat small intestine. II. Selective induction of inflammatory bowel disease could not be cor- suppressor T cells. Immunology 1986; 58: 9-14. related with the disease activity, its duration, or 6 Meyer L, Shlien R. Evidence for function of Ia molecules on gut epithelial cells in man. J Exp Med 1987; 166: 1471-83. extent of the disease pattern.21 t2 At the present 7 Bottazzo GF, Todd I, Mirakian R, Belfiore A, Pujol-Borrell R. time the autoimmune nature ofthe colitis cannot Organ-specific Autoimmunity: a 1986 overview. Immunol Rev 1986; 94: 137-69. be fully substantiated, although a cell mediated 8 Selby WS, Janossy G, Mason DY, Jewell DP. Expression of rather than a humoral immune mechanism may HLA-DR antigens by colonic epithelium in inflammatory bowel disease. Clin Exp Immunol 1983; 53: 614-8. be responsible for the present form of colitis, as 9 Arnaud-Battandier F, Cerf-Bensussan N, Amsellem R, has been suggested in other cases of inflamma- Schmidtz J. Increased HLA-DR expression by enterocytes in children with coeliac disease. Gastroenterology 1986; 91: tory bowel disease by some authors.2 122 1206-12. Finally, there are analogies between the gut 10 Brandtzaeg P, Sollid LM, Thrane PS, et al. Lymphoepithelial interactions in the mucosal immune system. Gut 1988; 29: disorder of the children described here and 1116-30. Crohn's disease: (a) diarrhoea with blood and 11 Londei M, Lamb JR, Bottazzo GF, Feldmann M. Epithelial cells expressing aberrant MHC Class II determinants can mucus is seen in both diseases; (b) both condi- present antigen to cloned human T cells. Nature 1984; 312: tions may affect the small intestine and the colon 639-41. 12 Bottazzo GF, Pujol-Borrel R, Hanafusa T, Feldmann M. Role with variable severity; (c) there are similar of aberrant HLA-DR expression and antigen presentation features of immune activation, such as inappro- in induction of endocrine autoimmunity. Lancet 1983; ii: 1115-9. priate class II expression in the epithelium and 13 Kitits G, Holmes GFT, Cooper BT, Thompson H, Allan RN. lymphocytic infiltration in the lamina propria; Association of coeliac disease and inflammatorv bowel disease. Gut 1980; 21: 636-41. (d) immunosuppressive treatment can be bene- 14 Peachey RDG, Creamer B, Pierre TW, et al. Sclerodematous ficial. involvement of the stomach and the small and large bowel. Gut 1969; 10:285-92. It will thus be important to follow up these 15 Ansaldi N, Santin B, Dell'Orso D, Lears P. Proctosigmoiditis patients for a long time to ascertain whether the and coeliac disease. Arch Dis Child 1978; 53: 645-8. 16 Sanderson IR, Boyle S, Williams CB, Walker-Smith JA. colonic involvement represents an early unusual Histological abnormalities in biopsies from macroscopicallv presentation of the better known overt inflam- normal colonoscopies. Arch Dis Child 1986; 61: 274-7. http://gut.bmj.com/ 17 Correani A, Pallone F, Accinni L, lannoni L, Natali P. matory bowel diseases or alternatively is a Chronic experimental colitis in rats induced bv a small bowel separate pathological entity from that affecting antigen. Itall Gastroenterol 1978; 10: 41-4. 18 Darr AS, Fuggle SV, Ting A, Fabri JW. Anomalous expres- the small intestine. sion of HLA-DR antigens on human colorectal cancer cells. JImmunol 1982; 128: 447-52. 19 Das KM, Dubin R, Nagai T. Isolation and characterisation of colonic tissue-bound antibodies from patients with idio- pathic ulcerative colitis. PNAS (USA) 1978; 75: 4528-32.

20 Nagai T, Das KM. Detection of colonic antigen(s) in tissues on September 30, 2021 by guest. Protected copyright. from ulcerative colitis using purified colitis colon tissue- bound IgG (CCA-IgG). Gastroenterology 1981; 81: 463-70. SH was in receipt ofa Training Research Fellowship from Action 21 Targan SR, Kagnoff MF, Brogan MD, Shanan F. Immuno- Research for the Crippled Child. We gratefully acknowledge logic mechanisms in intestinal diseases. Ann Intern Med generous financial support during this study from Crohn's in 1987; 106:853-70. Childhood Research Appeal (CICRA), and technical assistance 22 MacDermott RP, Stenson WF. Alterations of the immnune from Mr G Anderson. We thank Dr Marion Malone (Department system in ulcerative colitis and Crohn's disease. Adz ofHisthopathology) for her helpful comments and discussion. Immunol 1988; 42: 285-328.