Terminal Ileal Biopsies Research Articles

Cycling of gut mucosal CD4+ T cells decreases after prolonged anti-retroviral therapy and is associated with plasma LPS levels

The gut mucosa is an important site of HIV immunopathogenesis with severe depletion of CD4+ T cells occurring during acute infection. The effect of prolonged anti-retroviral therapy (ART) on cycling and restoration of T lymphocytes in the gut remains unclear. Colon and terminal ileal biopsies and peripheral blood samples were collected from viremic, untreated, HIV-infected participants, patients treated with prolonged ART (>5 years), and uninfected controls and analyzed by flow cytometry. In the gut, the proportion of cycling T cells decreased and the number of CD4+ T cells normalized in treated patients in parallel with β7 expression on CD4+ T cells in blood. Cycling of gut T cells in viremic patients was associated with increased plasma LPS levels, but not colonic HIV–RNA. These data suggest that gut T-cell activation and microbial translocation may be interconnected whereas prolonged ART may decrease activation and restore gut CD4+ T cells.

Giardiasis: An Under-Diagnosed Cause of Common Gastrointestinal Symptoms

Purpose: 1) To discuss giardiasis as an important but sometimes under-diagnosed etiology of common gastrointestinal symptoms. 2) To highlight the importance of basic diagnostic principles. Case: A 27-year-old male was referred to our center for a second opinion on chronic diarrhea. He complained of a 5-year history of 8 to 10 non-bloody, watery bowel movements, sometimes nocturnal. He also had intermittent, lower crampy abdominal pain. There was no fever, vomiting or weight loss. The patient sometimes consumed well water. Multiple upper endoscopic, colonoscopic and abdominal computed tomographic examinations had previously been negative. Duodenal, terminal ileal and colon biopsies had been read as normal. He was eventually diagnosed with irritable bowel syndrome and was treated with fiber, loperamide, antispasmodic agents and cholestyramine with no relief. Initial work-up in our clinic included blood tests to rule out anemia, hypoalbuminemia, hyperthyroidism and to screen for celiac disease. These were negative. Stool microscopy for ova, cysts and parasites was positive for Giardia lamblia cysts and trophozoites. Stool Giardia antigen was also positive. Review of outside duodenal biopsies from 2 years earlier showed Giardia organisms. No further diagnostic testing was recommended. The patient's symptoms partially responded to a 5-day course of metronidazole. He subsequently had a complete response to treatment with single-dose tinidazole. Discussion:Giardia lamblia is the most common gastrointestinal parasite in the United States. Well water is often implicated in the waterborne transmission of the pathogen. Symptoms can be variable and non-specific but diarrhea is the most frequently reported symptom. Stool microscopy of a single specimen can detect the organism in 50 percent of cases; the detection rate increases with three specimens. Stool antigen testing has a sensitivity and specificity of approximately 90 and 100 percent respectively. Duodenal biopsies can reveal the diagnosis but are usually normal. Oral metronidazole is commonly used as first-line treatment. Single-dose tinidazole is highly effective and Food and Drug Administration (FDA)-approved for the treatment of giardiasis. Conclusions: Giardiasis is the most common gastrointestinal parasitic infection in the United States and an important etiology of gastrointestinal symptoms in adults. It can easily be diagnosed by non-invasive stool tests. This case highlights the importance of awareness and maintaining a high index of suspicion for the disease, particularly in patients with risk factors. This case also demonstrates that a thorough diagnostic work-up does not necessarily translate to invasive, repetitive or costly testing.

Direct photographic documentation of ileal mucosa in routine colonoscopy is not an independent valid or reliable proof of completion: quality assurance issues for the national colorectal cancer‐screening programme

The implementation of bowel cancer screening in the UK requires the maintenance of high standards in colonoscopy. Part of this quality control requires the reliable documentation of complete colonoscopy that can be externally audited and assessed. It has been suggested that terminal ileal biopsy is the only definitive and reliable method of confirming caecal intubation, but it is not cost-effective and may now be contraindicated because of potential prion infection. To determine how reliable routine terminal ileal images were as an independent predictor of complete colonoscopy and whether their interpretation was aided with water insufflation or indigo-carmine dye-spraying. Method Forty-nine histologically confirmed terminal ileal images were obtained from a single endoscopist's database; 19 were conventional white-light images, 15 were taken with water insufflation and 15 were taken using chromoscopy enhancement. The images were transferred onto CD-ROM and sent as a questionnaire to 42 colonoscopists who were asked to identify the images as terminal ileum or not. Twenty questionnaires were returned resulting in a total of 980 responses. Overall, the accuracy of positive identification was 53.4%. Water insufflation and chromoscopy improved the accuracy to 68.3% and 63% respectively. Experience of (> 1000 colonoscopies) did not increase overall accuracy. Less experienced endoscopists had an increased accuracy rate with dye-spraying (76.7%vs 59.3%, P < 0.05) but experienced endoscopists had an increased accuracy rate with water insufflation (67.4%vs 63.3%, P > .05). Currently, terminal ileal imaging is not a reliable mode of documenting complete colonoscopy. Using water insufflation or dye-spraying coupled with modifications in image acquisition technique may improve its reliability but these methods require further investigation before they can replace the use of caecal landmarks as completion parameters.

Terminal ileal photography or biopsy to verify total colonoscopy: does the endoscope agree with the microscope?

Various modalities exist to document the extent of colonoscopy, including a terminal ileum (TI) biopsy, which is considered the criterion standard by some authorities. A TI biopsy adds to procedure costs, is potentially hazardous, and the detection of pathology in routinely acquired biopsy specimens of a macroscopically normal TI is limited. A safer, less costly alternative for documenting total colonoscopy is desirable. To evaluate the effectiveness of TI photography as a means of documenting total colonoscopy. We also assessed the diagnostic yield of TI biopsies in patients with a macroscopically normal TI. Prospective, observational study. District general hospital in the United Kingdom. A total of 232 unselected patients undergoing colonoscopy, TI intubation, photography, and biopsy. Independent, experienced endoscopists were asked to state whether villi (and, therefore, TI entry) were "definitely," "probably," or "definitely not" depicted in TI photographs. This was compared with TI histology as a means of verifying total colonoscopy. The diagnostic yield of biopsy specimens from a macroscopically normal TI was determined. Reviewers agreed that villi were "definitely present" in 93.8%, "probably present" in 5.9%, and "definitely not" present in 0.3% of cases, with excellent interobserver agreement (kappa value = 0.778, P < .0001). TI photographs "definitely" depicting villi (93.8%) did not differ significantly from histology confirming TI mucosa (96.1%, P = .285). Microscopic evidence of pathology was only detectable in 2.3% of patients with an endoscopically normal TI. TI photography is an effective, safe, and cost-effective means of documenting total colonoscopy. Routine biopsy of a "normal" TI has a low diagnostic yield.

The Diagnostic Value of Endoscopic Terminal Ileum Biopsies. CME

Biopsy of the terminal ileum (TI) is commonly performed during colonoscopy. The primary utility of this is to diagnose or rule out Crohn's disease in patients with symptoms and/or radiographic findings suggesting this diagnosis. We see many such biopsies in our gastrointestinal pathology service and have been impressed by the subjectively low yield of TI biopsies. Therefore, we studied this to obtain objective data. We retrospectively reviewed 414 consecutive patients with terminal ileal biopsies. Histologic parameters evaluated were primarily those changes diagnostic of chronic inflammation or its sequelae. Histologic findings were then compared with the indication(s) and endoscopic findings. The TI was histologically normal in 82% and endoscopically normal in 81% with most endoscopic abnormals having "ileitis" (13%). Known or strongly suspected inflammatory bowel disease was the most common indication (38%) with Crohn's disease accounting for 20% and ulcerative colitis 16% followed by diarrhea (33%), anemia/hematochezia (15%), abdominal pain (6%), and abnormal imaging (5%). Diagnostic yield varied, with indication and endoscopic findings being highest with known suspected Crohn's disease (40%), abnormal imaging (32%), and with endoscopic "ileitis" (84%) or ulcers/erosions (69%). Diagnostic yield of TI biopsy varied with indication and endoscopic findings. Our study indicates that biopsy is of greatest value in patients undergoing endoscopy for known or strongly suspected Crohn's disease, or with an abnormal imaging study of the TI. Biopsy of endoscopically normal mucosa is unlikely to yield diagnostically useful information, and is not encouraged as routine. However, when "ileitis," ulcers, or erosions are identified, biopsies can be very helpful.

Is Terminal Ileal Biopsy Worthwhile in Confirming Complete Colonoscopy?

Is Terminal Ileal Biopsy Worthwhile in Confirming Complete Colonoscopy?

Wegener Granulomatosis Mimicking Inflammatory Bowel Disease in a Pediatric Patient

Wegener Granulomatosis Mimicking Inflammatory Bowel Disease in a Pediatric Patient

The occurrence of terminal ileal histological abnormalities in patients with coeliac disease

Introduction Coeliac disease causes histological changes throughout the small bowel, but is often a proximal lesion. We wanted to assess whether terminal ileal histological abnormalities occurred more commonly in patients with coeliac disease and if specific assessment of intraepithelial lymphocytes increases the recognition of undiagnosed coeliac disease. Methods Terminal ileal biopsies were prospectively examined over a 3-year period (April 2001–May 2004). Patients were included if they were found to have a synchronous duodenal biopsy that gave a new diagnosis of coeliac disease ( n = 20). Terminal ileal biopsies taken at colonoscopy during the same period were also examined from four groups of patients: coeliac disease established on a gluten-free diet but with persisting symptoms ( n = 25), inflammatory bowel disease ( n = 47), chronic diarrhoea ( n = 44) and polyp surveillance ( n = 47). All biopsies were graded according to the Marsh criteria and an intraepithelial lymphocytes count per 100 enterocytes was obtained. Results There was only one patient from all five groups who had villous atrophy of the terminal ileal. This patient had a new diagnosis of coeliac disease. The mean intraepithelial lymphocytes count in the coeliac disease group was 23.7 intraepithelial lymphocytes/100 enterocytes. This was significantly higher than the control groups: coeliac disease on a gluten-free diet = 17.5 ( p < 0.012), inflammatory bowel disease = 12.3 ( p < 0.0001), diarrhoea = 12.6 ( p < 0.0001) and polyp = 13.7 ( p < 0.0002). Validating terminal ileal villous intraepithelial lymphocytes counts as a test for coeliac disease using an intraepithelial lymphocytes/100 enterocytes of >25 gives a sensitivity of 45% and a specificity of 97.8%. Conclusion Routinely quantifying terminal ileal intraepithelial lymphocytes may be of limited clinical value. However, subjective recognition of raised intraepithelial lymphocytes on a terminal ileal biopsy should alert the clinician to the possibility of coeliac disease.

It is not worthwhile to perform ileoscopy on all patients

It remains controversial whether ileoscopy should be attempted in all patients. Although the ease of ileoscopy and the diagnostic yield have been well described, there have been no studies describing the value of the diagnostic yield in altering clinical management. We carried out a study to ascertain whether it is worthwhile to perform ileoscopy in all patients having a colonoscopy. We carried out a retrospective study of all patients who had a colonoscopy between January 1, 2002, and December 31, 2003. The patient details, indications, findings, and complications of the procedure were recorded, together with the histopathology reports of colonic and terminal ileal biopsies. Clinical case note of patients with a positive diagnosis was reviewed to ascertain whether there was a change to the patient's management following an abnormal biopsy result. A total of 2,149 colonoscopies were performed. In 346 patients (16.1%), the terminal ileum was intubated. There were 16 abnormal findings on histology, which gave a diagnostic yield of 4.6% of all ileoscopies. A change to management occurred in only half of these patients. Ileoscopy should only be attempted in situations in which the indication is warranted and that would alter management. It is not cost-effective to carry out ileoscopy on all patients.

Butyrate metabolism in the terminal ileal mucosa of patients with ulcerative colitis.

The rate of oxidation of butyrate, glutamine and glucose was investigated in terminal ileal mucosal biopsy samples from nine patients with ulcerative colitis undergoing restorative proctocolectomy and from 12 patients undergoing laparotomy for reasons other than ulcerative colitis. Substrate oxidation was assayed using a radiolabelled isotope technique. Butyrate was the preferred fuel substrate, followed by glutamine and then glucose (median (95 per cent confidence interval) 567 (262-894), 63 (35-123) and 8.1 (5.1-18) pmol micrograms-1 h-1 respectively; P < 0.01, Mann-Whitney U test) in normal terminal ileal mucosa. The patients with ulcerative colitis had a significantly reduced rate of butyrate oxidation compared with the control group (194 (81-321) versus 567 (262-894) pmol micrograms-1 h-1, P < 0.05). Normal terminal ileal mucosa oxidized butyrate in greater quantities than glucose and glutamine. Ulcerative colitic terminal ileal mucosa exhibited an impaired rate of butyrate oxidation.

Histology of the terminal ileum in coeliac disease

Background: The histological lesion of gluten sensitivity primarily affects the proximal small bowel. The purpose of this study was to assess whether there were features of gluten‐sensitive enteropathy in biopsies taken from the terminal ileum during colonoscopy/ileoscopy. Specific and sensitive abnormalities might facilitate diagnosis of coeliac disease in patients undergoing colonoscopy as their initial procedure or help select those who should proceed to upper gastrointestinal endoscopy and duodenal biopsy. Methods: Terminal ileal biopsies, taken from 30 patients with duodenal villous atrophy consistent with coeliac disease and from 60 control patients with no evidence of coeliac or inflammatory bowel disease, were reviewed blindly and compared. Biopsies were assessed for the presence or absence of villous atrophy and crypt hyperplasia, and counts were made of intraepithelial lymphocytes (IELs). Results: One patient only, in the coeliac group, had partial villous atrophy with crypt hyperplasia in the terminal ileum. IEL counts were significantly higher (P < 0.005) in the coeliac group than among controls (mean per 100 enterocytes 26 versus 10). An ileal IEL count ≥25 had a sensitivity for duodenal villous atrophy (VA) of 60% and specificity of 100%. Conclusions: Coeliac disease may affect the entire small bowel. Increased IEL density in the terminal ileum is associated with duodenal VA and should prompt a search for coeliac disease by serology and duodenal biopsy. Conversely, a normal IEL count does not allow the exclusion of coeliac disease with confidence.

Small-bowel barium follow-through is rarely required in patients with a normal ileoscopy and terminal ileal biopsy and a normal or unremarkable colonoscopy

Background: There is an increase of reliance on ileoscopy in preference to small-bowel barium follow-through in the diagnosis of terminal ileal Crohn disease. In this study the role of small-bowel barium follow-through after a normal or unremarkable ileocolonoscopy was investigated. Methods: A retrospective analysis of all patients who had a colonoscopy followed by a small-bowel barium follow-through over a 7-year period was performed. Patients with a previously established diagnosis of inflammatory bowel disease and those who had colonoscopic evidence of inflammatory bowel disease were excluded. Results: Of the 96 patients who had a normal ileoscopy and normal or unremarkable colonoscopy, 3 had abnormalities detected at small-bowel barium follow-through. Two patients had abnormal terminal ileal biopsies, although the terminal ileum appeared macroscopically normal. The small-bowel barium follow-through helped to establish the diagnosis of Crohn disease. The other patient presented changes consistent with a previously established diagnosis. Of the 47 patients who had a normal or unremarkable total colonoscopy without ileoscopy, 1 had abnormalities detected at small-bowel barium follow-through consistent with a previously established diagnosis. Conclusions: Small-bowel barium follow-through is rarely required in patients who have had a normal ileoscopy and terminal ileum biopsy and a normal or unremarkable colonoscopy. It should only be performed if there is a very high index of suspicion of small-bowel pathology. In patients with suspected Crohn disease, it is important to take terminal ileum biopsies even if the ileum appears macroscopically normal at ileoscopy.

Combined terminal ileoscopy and biopsy is superior to small bowel follow-through in detecting terminal ileal pathology

Background. Several studies have compared small bowel barium examination with ileoscopy in assessment of terminal ileal disease. Some suggest that ileoscopy is superior in detection of terminal ileal disease whereas others suggest similar disease detection rates for both techniques. Aims. The aim of this retrospective study was to determine if small bowel follow-through and ileoscopy with terminal ileum biopsy compare favourably at detecting pathology in the terminal ileum. Patients and Methods. All colonoscopies with terminal ileoscopy performed over a 16-month period were reviewed. We determined which of these patients had also had small bowel follow-through studies within 2 weeks of colonoscopy. We compared the diagnoses of terminal ileum pathology using ileoscopy with terminal ileal biopsy versus small bowel follow-through. Results. Forty-six patients had both terminal ileoscopy with biopsy and small bowel follow-through. In 19 patients, the terminal ileum was abnormal at ileoscopy and/or biopsy but normal at small bowel follow-through. In 27 patients, terminal ileum findings at small bowel follow-through and at ileoscopy and/or biopsy were compatible. Conclusions. This study suggests that examination of the terminal ileum by combined ileoscopy and biopsy may be superior to small bowel follow-through at detecting terminal ileal pathology. In our series, many patients received effective treatment that otherwise would not have been offered based on the small bowel follow-through results alone. Using combined ileoscopy and biopsy, microscopic inflammatory changes, otherwise missed without biopsy, can be detected. Retrograde ileoscopy is recommended in patients with a clinical history of organic diarrhoea and/or abdominal pain even in the presence of a normal small bowel follow-through.

The terminal ileum is affected in patients with lymphocytic or collagenous colitis.

Lymphocytic colitis (LC) and collagenous colitis (CC) are diseases characterized by the presence of marked intraepithelial lymphocytosis. Both of these disorders affect primarily the colon. However, involvement of the distal small intestine has not been systematically studied. The purpose of this study was to evaluate the type and degree of intraepithelial lymphocytosis in the terminal ileum of patients with LC or CC. Terminal ileal mucosal biopsies from 22 patients with LC (male/female ratio 0.22, mean age 47 years) and 23 with CC (male/female ratio 0.43, mean age 54 years) were evaluated for the number of intraepithelial lymphocytes (IEL) per 100 epithelial cells (EC) both in the villi and crypts. The results were compared with 30 patients with inflammatory bowel disease (16 with Crohn's disease [CD], 14 with ulcerative colitis [UC]) and 24 patients (male/female ratio 0.33, mean age 44 years) without colonic pathology as normal controls. None of the patients had celiac sprue. Paired terminal ileum and colonic mucosal biopsies from 6 patients with LC, 4 with CC, 5 with CD, 5 with UC, and 10 normal controls were also immunohistochemically stained with monoclonal antibodies to CD3, CD8, CD20, and a class II MHC antigen (LN3-HLA-DR). In the villi the IEL count/100 EC was 11.8 +/- 1.8 in LC and 10.3 +/- 1.9 in CC (p = 0.3). These values were both significantly higher than in CD (2.8 +/- 0.4, p <0.001), UC (3.1 +/- 0.4, p <0.001), or normal controls (2.2 +/- 0.2, p <0.001). In the crypts the IEL count was 3.8 +/- 0.5 in LC and 3.2 +/- 0.5 in CC (p = 0.3). These values were also significantly higher than in CD (2.3 +/- 0.4, p = 0.02), UC (2.1 +/- 0.3, p = 0.02), or normal controls (1.5 +/- 0.2, p <0.001). The presence of >5 IELs/100 EC in terminal ileum biopsies was highly specific for LC and CC (specificity 98%, sensitivity 73% and 56% for LC and CC, respectively). The IEL phenotype was similar in all groups of patients and in the ileum and colon of individual patients. Intraepithelial lymphocytes were CD3+, CD8+, CD20-, and LN3-HLA-DR-, indicative of a suppressor T-cell phenotype. Intraepithelial lymphocytosis occurs in the terminal ileum in patients with LC or CC and may be helpful in diagnosing these conditions and distinguishing LC or CC from CD or UC in diagnostically difficult cases. The results suggest that the terminal ileum may be involved by a similar pathogenic process as the colon in LC and CC.

Terminal Ileum Intubation in Pediatric Colonoscopy and Diagnostic Value of Conventional Small Bowel Contrast Radiography in Pediatric Inflammatory Bowel Disease

ABSTRACTBackgroundSmall bowel contrast radiography is often suggested as the first diagnostic tool in evaluating pediatric inflammatory bowel disease. The purpose of this study was to determine the sensitivity and specificity of small bowel radiography compared with terminal ileal biopsies in diagnosing pediatric inflammatory bowel disease, and to determine the success rate and safety of terminal ileum intubation during pediatric colonoscopy.MethodsWe retrospectively reviewed the records of 164 subjects who had colonoscopies with terminal ileal biopsies between 1994 and 1996. Small bowel contrast radiography was performed in 84 subjects within two weeks of the colonoscopy. We also reviewed all the colonoscopy reports from the years 1994 to 1996 and 1999 to 2000 to determine the percentage of terminal ileal intubation.ResultsEighty‐four subjects with small bowel contrast radiography and terminal ileal biopsies were reviewed. Using small bowel radiography as a screening test for the diagnosis of terminal ileum inflammatory bowel disease resulted in a sensitivity of 45% (17/37) and a specificity of 96% (17/19). Between the years 1994 and 1996 the percentage of pediatric colonoscopies that resulted in terminal ileal intubation was 21.5%; between the years 1999 and 2000 the percentage increased to 65.6%.ConclusionsA normal small bowel radiography alone should not be used to rule out pediatric inflammatory bowel disease when the symptoms suggest it. Colonoscopy with terminal ileal intubation is feasible and safe; it should be attempted in all children with symptoms consistent with inflammatory bowel disease.

Terminal ileum intubation in pediatric colonoscopy and diagnostic value of conventional small bowel contrast radiography in pediatric inflammatory bowel disease.

Small bowel contrast radiography is often suggested as the first diagnostic tool in evaluating pediatric inflammatory bowel disease. The purpose of this study was to determine the sensitivity and specificity of small bowel radiography compared with terminal ileal biopsies in diagnosing pediatric inflammatory bowel disease, and to determine the success rate and safety of terminal ileum intubation during pediatric colonoscopy. We retrospectively reviewed the records of 164 subjects who had colonoscopies with terminal ileal biopsies between 1994 and 1996. Small bowel contrast radiography was performed in 84 subjects within two weeks of the colonoscopy. We also reviewed all the colonoscopy reports from the years 1994 to 1996 and 1999 to 2000 to determine the percentage of terminal ileal intubation. Eighty-four subjects with small bowel contrast radiography and terminal ileal biopsies were reviewed. Using small bowel radiography as a screening test for the diagnosis of terminal ileum inflammatory bowel disease resulted in a sensitivity of 45% (17/37) and a specificity of 96% (17/19). Between the years 1994 and 1996 the percentage of pediatric colonoscopies that resulted in terminal ileal intubation was 21.5%; between the years 1999 and 2000 the percentage increased to 65.6%. A normal small bowel radiography alone should not be used to rule out pediatric inflammatory bowel disease when the symptoms suggest it. Colonoscopy with terminal ileal intubation is feasible and safe; it should be attempted in all children with symptoms consistent with inflammatory bowel disease.

Confirmation of complete colonoscopy without intubation of the ileum

To establish whether biopsy of the ileocaecal valve from the caecum provides an alternative to the more technically demanding procedure of terminal ileal intubation and biopsy to document completion of colonoscopy. Fifty-three patients underwent colonoscopy at which the terminal ileum was intubated and biopsied and, after withdrawal of the endoscope tip into the caecum, the ileocaecal valve was then biopsied. To replicate the situation in which the ileum is not intubated, another group of 30 patients had ileocaecal valve biopsies taken from the caecum before ileal intubation was attempted. All of the terminal ileal biopsies obtained before ileocaecal valve biopsy showed small bowel mucosa, as did 51 (96%) of the ileocaecal valve specimens from this group. When ileocaecal valve biopsy was obtained first, 16 (53%) specimens contained small bowel mucosa. Ileocaecal valve biopsies were significantly more likely to yield small bowel mucosa if taken after ileal intubation (P < 0.001, Fisher's exact test). Nevertheless, about half of ileocaecal valve biopsies taken without ileal intubation contained small bowel mucosa, providing evidence of complete colonoscopy in these cases. Terminal ileal intubation and biopsy, however, remains the only reliable way to document complete colonoscopy.

A prospective study of endoscopy in HIV-associated diarrhea

OBJECTIVE: Diarrhea commonly occurs in persons with human immunodeficiency virus (HIV) infection. The optimal use of endoscopic procedures remains poorly studied for patients with HIV-related diarrhea. The purpose of this study is to compare the diagnostic yield of a complete endoscopic work-up including an esophagogastroduodenoscopy and colonoscopy to a more limited approach of biopsies obtainable by flexible sigmoidoscopy. METHODS: A prospective study of 79 patients with HIV-related diarrhea. Upper endoscopy and colonoscopy were performed with tissue biopsies labelled according to location within the colon or small intestine. RESULTS: A new infection was diagnosed in 22 of 79 patients (28%). Biopsy of the left colon yielded an enteric pathogen in 17 of 22 patients (sensitivity: 77%) and in 15 of 15 patients with cytomegalovirus colitis (sensitivity: 100%). Combined left and right colonic biopsies had a sensitivity of 82%. Combined colonic and terminal ileum biopsies missed no pathogens. Duodenal biopsies yielded no additional pathogens beyond those identified by colonoscopy and terminal ileal biopsy. Patients with a new pathogen diagnosed had significantly lower CD4 lymphocyte counts as compared to patients without a new pathogen ( p = 0.001). CONCLUSIONS: For patients with CD4 counts < 100/mm 3 and unexplained AIDS-related diarrhea, flexible sigmoidoscopy with biopsy is a sufficiently thorough endoscopic evaluation.

A prospective study of endoscopy in HIV-associated diarrhea.

Diarrhea commonly occurs in persons with human immunodeficiency virus (HIV) infection. The optimal use of endoscopic procedures remains poorly studied for patients with HIV-related diarrhea. The purpose of this study is to compare the diagnostic yield of a complete endoscopic work-up including an esophagogastroduodenoscopy and colonoscopy to a more limited approach of biopsies obtainable by flexible sigmoidoscopy. A prospective study of 79 patients with HIV-related diarrhea. Upper endoscopy and colonoscopy were performed with tissue biopsies labelled according to location within the colon or small intestine. A new infection was diagnosed in 22 of 79 patients (28%). Biopsy of the left colon yielded an enteric pathogen in 17 of 22 patients (sensitivity: 77%) and in 15 of 15 patients with cytomegalovirus colitis (sensitivity: 100%). Combined left and right colonic biopsies had a sensitivity of 82%. Combined colonic and terminal ileum biopsies missed no pathogens. Duodenal biopsies yielded no additional pathogens beyond those identified by colonoscopy and terminal ileal biopsy. Patients with a new pathogen diagnosed had significantly lower CD4 lymphocyte counts as compared to patients without a new pathogen (p = 0.001). For patients with CD4 counts < 100/mm3 and unexplained AIDS-related diarrhea, flexible sigmoidoscopy with biopsy is a sufficiently thorough endoscopic evaluation.

Intestinal inflammation, ileal structure and function in HIV.

This study examines small intestinal absorption-permeability, intestinal inflammation and ileal structure and function in HIV-positive male homosexuals. Thirty HIV-seropositive male homosexuals at various stages of disease underwent intestinal absorption permeability and 111indium leukocyte studies (for quantification of intestinal inflammation). Twenty-six men with AIDS had a dual radioisotopic ileal function test (whole body retention of tauro 23-[75Se]-selena 25-homocholic acid and 58cobalt-labelled cyanocobalamine), and 17 underwent ileocolonoscopy with terminal ileal biopsy. Well, HIV-infected, subjects had normal intestinal absorption-permeability, but both functions were impaired upon the development of AIDS. The median faecal excretion of 111indium in well patients (0.66%) did not differ significantly (P > 0.5) from controls (0.46%), but subjects with AIDS who were well or who had diarrhoea had significant (P < 0.005) intestinal inflammation (1.33% and 2.18%, respectively). The median 7-day retention of tauro 23-[75Se]-selena 25-homocholic acid in well patients with AIDS (38.9%) did not differ significantly (P > 0.2) from controls (39.3%), whereas the absorption of 58cobalt-labelled cyanocobalamine was significantly (P < 0.05) lower than controls (32.1% and 59.4%). Patients with AIDS-diarrhoea had significant (P < 0.001) malabsorption of both the bile acid (7.7%) and vitamin B12 (8.9%) which was more severe than in Crohn's ileitis (14.2% and 30.3%, respectively). Morphometric analyses of ileal biopsies were unremarkable in AIDS. These studies demonstrate a low-grade enteropathy in patients with AIDS, severe ileal malabsorption in patients with AIDS diarrhoea and relatively minor ileal morphologic changes. Malabsorption of bile acids may play a pathogenic role in patients with AIDS and diarrhoea.