Genetic Aspects of Inflammatory Bowel Disease

Angiotensin-converting enzyme insertion/deletion gene polymorphism in inflammatory bowel diseases

INTRODUCTION

The renin-angiotensin system is strictly related to the kallikrein-kinin system and both are involved in many physiological and disease conditions and possibly in the pathogenesis of inflammatory bowel disease (IBD). Angiotensin-converting enzyme (ACE) is the pivotal enzyme of the renin-angiotensin system and the main catabolic enzyme of the kallikrein-kinin system. The ACE I/D (insertion/deletion) is a polymorphism of the gene encoding for ACE: participants who are homozygous for the D allele exhibit higher ACE levels, which in turn appear to play a deleterious role in several diseases.

AIM

To study the prevalence of ACE I/D polymorphism in IBD patients and its possible association with disease features.

METHODS

A total of 232 IBD patients, 124 with ulcerative colitis (UC) and 108 with Crohn's disease and 99 healthy controls were genotyped for the ACE I/D polymorphism.

RESULTS

DD, ID and II genotypes distribution did not show significant differences between IBD patients and controls: 42.2 vs. 40.4%, 42.7 vs. 47.5% and 15.1 vs. 12.1%, respectively. No significant difference was observed between Crohn's disease and UC patients. Within UC patients, the presence of DD genotype and the carriage of the D allele were significantly associated with the presence of extraintestinal manifestations: odds ratio (OR) 4.08, 95% confidence interval (CI): 1.62-10.28; P<0.003 and OR=3.07, 95% CI: 1.45-6.48; P<0.003, respectively. No significant association was found with other IBD clinical features.

CONCLUSIONS

The ACE I/D polymorphism is not associated with IBDs but the D allele appears to increase the risk of developing extraintestinal manifestations in UC patients.

Familial and sporadic inflammatory bowel disease: different entities?

The strongest risk factor for developing inflammatory bowel disease (IBD) is having a relative with the disease. Familial IBD may be one homogeneous subgroup, phenotypically different from sporadic IBD. Several observations support a role for familiarity in disease site and behavior, particularly in Crohn's disease (CD), but published findings do not all concur. Early disease onset is often found in children with IBD who have a parent with the disease. Genetic anticipation may explain this finding but other explanations and/or observational biasis are more likely. Location and type may differ between familial and sporadic CD cases: family studies report many cases involving both small bowel and colon, and few cases of colonic disease alone, although such features may be secondary to early age at onset. Most studies found no effect of positive family history on severity and course of CD. In ulcerative colitis (UC), phenotypic differences between familial and sporadic cases appear to be limited, but little data are available for analysis. No difference has been found between familial and sporadic IBD as far as disease markers such as pANCA, ASCA, or intestinal permeability are concerned. In conclusion, the only message available for clinical practice is that the relative risk of IBD in first-degree relatives is increased by a factor of 10-15 compared with the general population. Families should not receive genetic counseling/information about age at onset and disease severity.

[Initial symptoms, extra-intestinal manifestations and course of pregnancy in chronic inflammatory bowel diseases]

BACKGROUND

In many cases inflammatory bowel disease is accompanied by extraintestinal manifestations. This results in lowering of live quality. The aim of this study was to gather data retrospectively about initial symptoms, extraintestinal manifestations and course of pregnancy in a large unselected population with inflammatory bowel disease in South Germany.

PATIENTS AND METHODS

Data from 1975 to 1989 (392 patients) were analyzed and partially compared with data from 1992 to 1995 (211 patients).

RESULTS

Patients with Crohn's disease in average have been 25 years old at the time point of initial symptoms, whereas the age of ulcerative colitis patients was 30 years (p < 0.0001). The number of Crohn's disease patients with a long interval between initial symptoms and diagnosis (> 1 year) was significantly decreased in the second population (50% vs 38%; p < 0.05). Dominant initial symptoms in Crohn's disease were indisposition, abdominal pain and nonbloody diarrhea in contrast to ulcerative colitis which manifested mostly with bloody diarrhea. Extraintestinal manifestations occurred in 76% of patients with Crohn's disease and 64.6% with ulcerative colitis. Complications during the course of pregnancy have been detected in 40.5% in Crohn's disease and 60% in ulcerative colitis.

CONCLUSION

A better knowledge of initial symptoms and extraintestinal manifestations in inflammatory bowel disease can help to decrease the interval between initial symptoms and the diagnosis. Pregnancy in patients with inflammatory bowel disease needs to be treated with special care.

Porokeratosis and Crohn's disease

We report the cases of three patients with Crohn's disease in whom porokeratosis developed. Disseminated superficial actinic porokeratosis developed in two patients. In one of these patients, the skin lesions arose during an exacerbation of the bowel disease. In the third patient, who had congenital linear porokeratosis, the disseminated superficial form of the disorder developed during the first severe exacerbation of Crohn's disease. A family history of porokeratosis was present in one patient, but no relatives of any of these patients were known to have Crohn's disease. In all three patients, Crohn's disease was limited to the colon.

Inflammatory bowel disease in married couples: 10 cases in Nord Pas de Calais region of France and Liège county of Belgium

Ten pairs of husband-wife couples are reported with inflammatory bowel disease who were seen in the same geographical area in Nord Pas de Calais region of France and in Liège county (Belgium). Among these 10 couples, four were concordant for Crohn's disease, two for ulcerative colitis, and four were discordant. In nine of 10 couples neither spouse had symptoms before marriage but inflammatory bowel disease subsequently developed in both. In one couple, one spouse had Crohn's disease before marriage and the other partner experienced symptoms afterwards. Eighteen children were born to eight of 10 couples. Five of them developed Crohn's disease but four belong to the same family. In all cases the affected children were born to parents who both developed Crohn's disease after they had married and were conceived at a time when parents did not yet have symptoms. It is proposed that this pattern of emergence of inflammatory bowel disease suggests a role for an infectious agent yet to be identified.

Familial empirical risks for inflammatory bowel disease: differences between Jews and non-Jews

The Jewish population has an increased frequency of inflammatory bowel disease compared with their non-Jewish neighbours. Genetic factors have been implicated in the aetiology of this disorder and may contribute to ethnic differences. This study determined the familial empirical risks for inflammatory bowel disease in the first degree relatives of inflammatory bowel disease probands (for both Jews and non-Jews) for the purpose of accurate genetic counselling and genetic analysis. A total of 527 inflammatory bowel disease patients from Southern California (291 Jews and 236 non-Jews) were questioned about inflammatory bowel disease in their first degree relatives (a total of 2493 individuals). Since inflammatory bowel disease has a variable and late age of onset, age specific incidence data were used to estimate the life time risks and to make valid comparisons between the different groups. In the first degree relatives of non-Jewish probands, the life time risks for inflammatory bowel disease were 5.2% and 1.6% when probands had Crohn's disease and ulcerative colitis respectively. These values were consistently lower than the corresponding risks for relatives of Jewish patients -7.8% and 4.5% for Crohn's disease and ulcerative colitis probands respectively (p value for comparison between Jews and non-Jews: 0.028; between ulcerative colitis and Crohn's disease: 0.005). These data provide the requisite basis for genetic counselling for these disorders in the white American population. In addition, these different empirical risks for relatives of Jewish and non-Jewish probands allow rejection of single Mendelian gene models for inflammatory bowel disease, but are consistent with several alternative genetic models.

Familial aggregation of inflammatory bowel disease in northern Italy: a multicenter study. The Gruppo di Studio per le Malattie Infiammatorie Intestinali (IBD Study Group)

To assess the familial aggregation of inflammatory bowel disease (IBD) in Italy, the family pedigrees of 411 patients with ulcerative colitis (UC) and 241 patients with Crohn's disease (CD) seen at 14 participating hospitals were studied. Sufficient information was obtained on 97% of 3752 first-degree relatives, 80% of 8869 second-degree relatives, and 74% of 5791 cousins. Thirty-six propositi (5.52%) had a total of 44 affected relatives (16 CD, 28 UC). The prevalence of IBD was higher in first- than in second-degree relatives and cousins (791, 112, and 163 in 100,000, respectively). A strong intrafamilial disease concordance was observed, with 26 cases of UC and 6 of CD among relatives of UC patients and 10 cases of CD and 2 of UC among relatives of CD patients. The prevalence of UC among first-degree relatives of UC patients and that of CD among first-degree relatives of CD patients was 680 and 531 in 100,000, respectively. In conclusion, there is a high degree of familial aggregation for IBD in Italy, with a strong intrafamilial disease concordance.

Data management of an inflammatory bowel disease registry

The history and etiology of inflammatory bowel disease which is characterized by two major disease processes: ulcerative colitis and Crohn's disease, remain unknown. Research is focussing on seven major areas of genetic, environmental and physiologic factors that apparently relate to this disease. Based on this background, a population based Inflammatory Bowel Disease Registry was established in 1987 in the Lehigh Valley area of southeastern Pennsylvania. Consent forms, patient data forms and protocols for operation and implementation were developed, and databases were designed to accommodate demographic, basic history, follow-up and relative history data. The databases were correlated with an IBD registry ID number which both enabled relational analyses and ensured confidentiality of data information. The registry continues to grow, providing feedback for both continued medical research and supportive information for IBD patients and their physicians.

Inflammatory bowel disease. Part I: Nature and pathogenesis

Once regarded as medical curiosities, ulcerative colitis and Crohn's disease have achieved a remarkable change in status recently and today are among the more compelling of all human illnesses. The cause(s) of inflammatory bowel disease (IBD) are not known. Genetic, environmental, microbial, and immunologic factors are involved, but the precise mechanisms are obscure. The incidence of ulcerative colitis is relatively stable, while Crohn's disease continues to increase in frequency. In 10% to 15% of patients, it is hard to differentiate between ulcerative colitis and Crohn's colitis; however, problems with diagnosis usually resolve with time and repeated examinations. In part I of his two-part monograph on IBD, Dr. Kirsner addresses the nature and pathogenesis of the disease. Increased study of ulcerative colitis and Crohn's disease in recent years has generated new knowledge regarding their etiology. Part I focuses on microbial, immunologic, and genetic mechanisms and the inflammatory processes involved in the disease. In part II, which will be presented in next month's issue of Disease-a-Month, Dr. Kirsner deals with the clinical features, course, and management of IBD, based on the author's 55 years of experience with these problems and supplemented by critical examination of the recent (1988-1990) literature. Particular attention is directed to the symptoms and physical findings of ulcerative colitis and Crohn's disease, the laboratory, radiologic, endoscopic, and pathologic features, and the many systemic complications. The IBDs are mimicked by several enterocolonic infections and other conditions, making differential diagnosis necessary. Inflammatory bowel disease in children and the elderly conforms to conventional clinical patterns modified by the health circumstances of the respective age groups. Because the cause of IBD has not been established, current medical therapy is facilitative and supportive rather than curative. The principles of medical treatment are approximately the same for ulcerative colitis and Crohn's disease. Treatment emphasizes a program rather than a drug and also considers the individuality of the therapeutic response. A clearer understanding of dietary and nutritional needs, including hyperalimentation and electrolyte and fluid balance, aids treatment. Antidiarrheal and antispasmodic preparations and sedatives are prescribed for symptom relief. The bowel inflammation is controlled with sulfasalazine or the newer 5-amino salicylic acid (5-ASA) compounds, antibacterial drugs for complications of Crohn's disease and IBD, adrenocortical steroids, and the immunosuppressive compounds 6-mercaptopurine (6-MP), azathioprine, and cyclosporine, as determined in each patient. The surgical procedures available for treatment of ulcerative colitis include total proctocolectomy and ileostomy or ileoanal anastomosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Frequency of inflammatory bowel disease in offspring of couples both presenting with inflammatory bowel disease

A private practice was surveyed for prevalence of inflammatory bowel disease (IBD) in husband-wife partners and in their children. Among approximately 2500 patients with IBD in our files, 19 couples were identified. They were subdivided into group A (n = 5) in which both partners had symptoms of IBD before marriage; group B (n = 7) in which only one spouse had IBD before marriage and the other partner experienced symptoms afterwards; and group C (n = 7) in which neither spouse had symptoms before marriage but IBD subsequently developed in both. In group B, the disease developed in the second spouse 2-16 years after marriage (mean, 6.4 years). In group C, IBD developed in the first spouse 0.3-41 years after marriage and in the second spouse 1-14 years after the first spouse (mean, 6.8 years). Thirty-five children have been born to 16 of the couples. Two children died before age 20. Of the surviving 33 children, IBD has already developed in 12 (36%). Among the other 21 unaffected children, 1 had uveitis at age 9 and 10 are still under the age of 21, perhaps too young to have yet developed IBD. The frequency of IBD in children was slightly higher if both parents had already developed IBD at the time of conception (67%) compared with when only 1 parent (50%) or neither parent (50%) had developed IBD when conception occurred. Although these data do not distinguish genetic from environmental factors, they show a higher risk of IBD in children when both parents have this illness.

Ampullary carcinoma associated with familial polyposis coli--a case report

We report herein a case of a 43 year old female who was found to have developed ampullary carcinoma seven years following a subtotal colectomy for familial polyposis coli. She presented to us with only a light fever and early stage ampullary carcinoma was subsequently diagnosed by endoscopic examination of the upper gastrointestinal tract, including an endoscopic retrograde choledochopancreatography. The patient is presently alive and well without any evidence of recurrence 33 months after undergoing a pancreaticoduodenectomy.

Inflammatory bowel disease in Japan: studies of epidemiology and etiopathogenesis

The epidemiologic features of inflammatory bowel disease in Japan are somewhat different from the western features. Many immunologic abnormalities are observed, but without primary evidence for etiology. There are some differences regarding epidemiologic and immunologic aspects between ulcerative colitis and Crohn's disease. Bacteriovirological studies have not shown specific pathogens, but suggest that the enteric bacteria flora is significantly involved in the pathogenesis.

Medical management of inflammatory bowel disease

Inflammatory bowel disease is a serious ailment that afflicts nearly one million people in the U.S. alone. The medical management of this disorder currently includes salicylates, corticosteroids, immunosuppressive therapy, and symptomatic treatment with antidiarrheal agents, although several promising new drugs have been developed. The epidemiology, etiology, pathogenesis, and medical management of the disease are discussed in this article.

Geographic origins of Jewish patients with inflammatory bowel disease

Ulcerative colitis and Crohn's disease are more common among Jews than among non-Jews. Despite the existence of studies on the prevalence and incidence of inflammatory bowel disease in relation to the continent of residence or origin, there are no studies on the specific countries of origin of Ashkenazi Jewish patients. We report here the first analysis of 233 U.S. Jewish patients by defined world regions and subregions. Using two different sets of controls (a self-referred Jewish population for Tay-Sachs disease carrier detection and a sample of Jewish persons ascertained through unrelated studies from the same hospital as our patients), we found a significant excess of patients of middle European origin relative to those of Polish or Russian origin. These observations suggest that the inflammatory bowel disease gene(s) are more prevalent in the Jewish population that originated in middle Europe than in those from Poland and Russia. These results further suggest that Jewish patients with inflammatory bowel disease probably represent a nonrandom genetically predisposed subset of the Jewish population. This provides further evidence for the genetic contribution to inflammatory bowel disease in general, and to its higher risk in the Jewish population.

Familial empiric risk estimates of inflammatory bowel disease in Ashkenazi Jews

Genetic factors have been implicated in the etiology of inflammatory bowel disease (IBD) because of the increased occurrence of IBD in relatives. To further characterize the familial aggregation of IBD, we obtained family histories by interview on 188 IBD patients, including 154 Ashkenazi Jews (82%), ascertained through a Los Angeles gastroenterology practice. Thirty-three index cases (17.6%) had at least one affected first-degree relative; an additional 11 had more distant affected relatives. Thus, 23.4% of our sample had a positive family history. The quantification of empiric risk estimates for various classes of relatives has been quite limited and has been reported in only a few series. An important goal of our study was the determination of the specific empiric risk figures for relatives. We obtained uncorrected risk estimates of 2.5% to off-spring, 5.2% to siblings, and 2.9% to parents. Although the highest risk we observed is to siblings, IBD has a variable and often late age of onset, and it is likely that many relatives, particularly offspring, of patients in this sample have not reached the age at which they will manifest clinical disease. Thus, these uncorrected risks as well as those reported in the literature are an underestimate of the true empiric risks. To provide an estimate of the true lifetime risks, we utilized age-specific incidence data to calculate the following age-corrected empiric risk estimates for IBD: 8.9% to offspring, 8.8% to siblings, and 3.5% to parents. It is these latter age-corrected estimates that are most appropriate for both genetic counseling and genetic modeling.

The obligate anaerobic faecal flora of patients with Crohn's disease and their first-degree relatives

The obligate anaerobic faecal floras of patients with Crohn's disease, their first-degree relatives, and healthy control subjects were compared. The flora of Crohn's patients contained more anaerobic gram-positive coccoid rods and gram-negative rods than that of healthy subjects; on this basis patients and healthy subjects formed two clusters with minor overlap. Nine of 26 children of Crohn's patients were also included within the Crohn's disease cluster. During 5 to 7 years of follow-up study 3 of them presented with remitting abdominal pain, diarrhoea, or weight loss, and in 1 of them Crohn's disease was diagnosed; none of the 17 children with a normal flora showed symptoms possibly due to Crohn's disease. It is concluded that the abnormal flora may be indigenous to subjects predisposed to Crohn's disease, suggesting a direct or indirect relationship between the abnormal faecal flora and Crohn's disease.

Ulcerative colitis and Crohn's disease in an unselected population of monozygotic and dizygotic twins. A study of heritability and the influence of smoking

By running the Swedish twin registry containing about 25,000 pairs of twins of the same sex together with the central national diagnosis register of hospital inpatients, 80 twin pairs suffering from inflammatory bowel disease were found. In the ulcerative colitis group one of 16 monozygotic pairs was concordant for the disease, but all the other 20 pairs (dizygotic or unknown zygosity) were discordant. In the Crohn's disease group eight of 18 monozygotic pairs and one of 26 dizygotic pairs were concordant. The proband concordance rate among monozygotic twins was 6.3% for ulcerative colitis and 58.3% for Crohn's disease. The calculated heritability of liability based on monozygotic pairs was 0.53 and 1.0 respectively. Thus heredity as an aetiological factor is stronger in Crohn's disease than in ulcerative colitis. Monozygotic twins with Crohn's disease were more likely to be smokers than monozygotic twins with ulcerative colitis. Smoking did not explain the discordance of twin pairs with either ulcerative colitis, or Crohn's disease. The combination of identical heredity and similar smoking habit is not sufficient to cause disease.

Prevalence of inflammatory bowel disease among relatives of patients with ulcerative colitis

The familial occurrence of inflammatory bowel disease (IBD) was investigated among 963 patients with ulcerative colitis (UC) diagnosed in 1955-1979 in Stockholm County. For 76 patients who had a relative with IBD a pedigree was drawn. The diagnoses of the diseased relatives were verified. There was a general prevalence of 7.9% for IBD among relatives. In 80% one relative was affected, in most cases a first-degree relative with UC. Sibship was the commonest relationship. No concordance for UC was found among three pairs of monozygotic twins. The prevalence of UC in first-degree relatives was 15 times higher than in non-relatives. The age of onset was significantly lower among patients with a family history for UC; they also had a higher incidence of total colitis. The prevalence of Crohn's disease in first-degree relatives of patients with UC was almost 3.5 times higher than in non-relatives.

Monozygotic triplets with Crohn's disease of the colon

Female monozygotic triplets all developed Crohn's disease within a period of 11 mo. The monozygosity was demonstrated by analysis of 24 genetic markers of different chromosomal localization. Crohn's disease was diagnosed using clinical, radiologic, and endoscopic findings. Histologic evaluation of bowel tissue was consistent with Crohn's disease. All 3 patients had colon involvement; the terminal ileum appeared normal. The patient in whom Crohn's disease was first diagnosed had the severest course. Our observations support the role of a genetic influence in the manifestation of Crohn's disease. Nevertheless, environmental factors or microorganisms, or both, have to be taken into account, perhaps as factors promoting the outbreak of Crohn's disease.

Prevalence and incidence of inflammatory bowel disease in family members

To determine the risk of having or developing inflammatory bowel disease (IBD) in a family member of an IBD patient, a population of 245 IBD probands was randomly selected from the University of Chicago IBD Registry and their family history was elucidated by questionnaire and follow-up telephone call. One hundred seventy-nine (73%) probands responded to the questionnaire. There were no demographic distinctions between those eligible for the study, those who were complete responders, those who were nonresponders, and those with a positive family history of IBD. Fifty-four family members from 40 proband families (22%) had confirmed IBD. Prevalence of IBD in family members at the time of diagnosis of the proband was highest for parents (4.6%), siblings (2.6%), and children (1.9%). Grandparents, aunts and uncles, and first cousins had prevalence of IBD of less than 1%. Incident case frequency was determined by dividing the number of cases incident after the diagnosis of the proband by all those ever at risk. The incident case frequency was highest for siblings (1.9%), parents (1.0%), and children (1.0%). There was concordance noted for type of disease in the proband and the relative. No association could be discerned between the familial risk of IBD and gender, race, or religion of the proband. Despite a high occurrence rate of proband families with IBD, the specific risk to first, second, or third degree family members is low.

Ulcerative colitis and Crohn's disease on the Faroe Islands 1964-83. A retrospective epidemiological survey

The frequency of inflammatory bowel disease in the Faroe Islands was estimated retrospectively for the years 1964 to 1983. A pronounced increase in the incidence of ulcerative colitis from 2.1 to 12.8 per 100,000 was found. The mean incidence in the period was 7.5/100,000; the prevalence was 157.3/100,000 on 31 December 1983. The change in frequency of Crohn's disease was insignificant, and the incidence of the disease was low compared with in other countries (1.75/100,000); the prevalence was 31.8/100,000 on 31 December 1983. The increase in incidence rate of ulcerative colitis was distributed equally between the two sexes, and a pronounced increment was found among young women.

[Genetics of Crohn disease: study of the HLA association in 169 patients]

Histocompatibility (HLA) antigen phenotypes have been studied in 169 patients with Crohn's disease. The following results could bei shown: HLA-Aw33, -B45 and -Cw3 showed a positive association and HLA-A26, -DR3 and -DRw8 a negative association with Crohn's disease compared to healthy controls. However, when the p-values were corrected by multiplying them by the number of determined antigens per gen-locus, the differences were not significant. Patients with a late onset of the disease (greater than 25 years) showed a statistical significant negative association with HLA-DR3. Numerous studies revealed no significant association between Crohn's disease and HLA-antigens except Smolen et al. (HLA-B12). The significant association of Crohn's disease and HLA-B12 reported by Smolen et al. could be caused by an increased frequency of HLA-B45 as we found in our patients.

Regional enteritis and HLA concordance in multiple siblings

A familial predisposition to ulcerative colitis and Crohn's disease is well established, and linkage of a susceptibility gene to the HLA gene locus has been postulated. We report here a family of five children, at least four and probably all five of whom have Crohn's disease. HLA studies of four of the five showed three with the same paternal haplotypes (A2, B44), all four with the same maternal haplotypes (A30, B17), and three of the four to be HLA identical. combination of this data with four studies in the literature shows an excess of shared haplotypes among sibling pairs with disease, but the excess does not reach statistical significance. Thus, although the data shows a trend, Crohn's disease susceptibility linkage to the HLA gene locus is still unsettled. Lymphocytotoxic antibody was present in two of the four children but in neither parent.

The incidence and prevalence of inflammatory bowel disease in North Tees Health District

The experience with inflammatory bowel disease in a stable, defined population in northeast England is described. In this population, the incidence of inflammatory bowel disease was higher than expected. In particular, a high incidence of colorectal and anal Crohn's disease was found. The literature is reviewed in order to identify some of the factors responsible for this unusual prevalence of inflammatory bowel disease in the study population. No explanation for our unexpected findings can be advanced.

Crohn's disease in a husband and wife

The case-histories of a husband and wife in whom Crohn's disease developed after more than 30 years of marriage are described.

Significance of anergy to dinitrochlorobenzene (DNCB) in inflammatory bowel disease: family and postoperative studies

To evaluate the pathogenetic significance of impaired cellular immunity in inflammatory bowel disease (IBD), we have measured the cutaneous responsiveness to dinitrochlorobenzene (DNCB) among 58 patients with IBD, 33 with Crohn's disease and 25 with ulcerative colitis, 63 of their clinically normal relatives, 24 additional ileitis and colitis patients who had undergone resection of all visibly diseased bowel, and 23 control subjects. Cutaneous anergy to DNCB was demonstrated among 70% of the patients with CD and 48% of those with UC, as against only 9% of the controls (p less than 0.001). There was no increased incidence of anergy among either 44 first-degree relatives (7%) or 19 spouses (3%), nor was there any special proclivity toward anergy among six pairs of patients with familial inflammatory bowel disease. In Crohn's disease, anergy was still present after bowel resection in six of 10 patients (60%), while in ulcerative colitis anergy was found after colectomy in only two of 14 patients (14%). Our data suggest that the immune defect in patients with inflammatory bowel disease may be a secondary phenomenon. In ulcerative colitis, the defect appears to reverse after colectomy, but in Crohn's disease it persists despite resection. This finding is consistent with the observed tendency of Crohn's disease, but not ulcerative colitis, to inexorable postoperative recurrence.