Evaluation of oxidative stress in an experimental model of Crohn's disease treated with hyperbaric oxygen therapy

INTRODUCTION

Treatments of Inflammatory Bowel Disease (IBD) are able to control symptoms in most cases, however, a fraction of patients do not improve or have a loss of response to treatments, making it important to explore new therapeutic strategies. Hyperbaric oxygen therapy (HBO) may represent one of them. The aim of this study was to evaluate the effects of HBO therapy in an experimental model of IBD.

METHODS

Sixty male BALBc mice were divided into six groups. Group 1 was colitis-induced with trinitrobenzene sulfonic acid (TNBS) + ethanol, group 2 received TNBS + ethanol plus HBO, group 3 received only ethanol, group 4 received ethanol plus HBO, group 5 received saline solution, and group 6 received saline solution plus HBO. HBO was performed for four days, subsequently, the mice were evaluated daily. At the end of the study, samples from the intestine were collected for histological analysis as well as for measurement of antioxidant enzymes and cytokine levels.

RESULTS

HBO significantly improved the clinical and histological status of the animals. Treatment with HBO increased the activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) in all of the groups; moreover, the difference was only significant between the TNBS and TNBS + HBO groups and treatments promoted a reduction in the proinflammatory cytokines IFN-γ, IL-12, IL-17 and TNF-α and increased the anti-inflammatory cytokines IL-4 and IL-10, with no changes in IL-13.

CONCLUSION

HBO effectively treats TNBS-induced colitis by increasing the activity of antioxidant enzymes and modulating cytokine profiles.

Active tuberculosis in inflammatory bowel disease patients: a case-control study

Background/Aims

Anti-tumor necrosis factor (anti-TNF) drugs have been the mainstay therapy for moderate to severe inflammatory bowel disease (IBD) over the past 25 years. Nevertheless, these drugs are associated with serious opportunistic infections like tuberculosis (TB). Brazil is ranked among the 30 countries with the highest incidence of TB in the world. This study aimed at identifying risk factors for the development of active TB and describing clinical characteristics and outcomes in IBD patients followed at a tertiary referral center in Brazil.

Methods

We conducted a retrospective, case-control study between January 2010 and December 2021. Active TB cases in IBD patients were randomly matched 1:3 to controls (IBD patients with no previous history of active TB) according to gender, age, and type of IBD.

Design

This was a retrospective, case-control study.

Results

A total of 38 (2.2%) cases of TB were identified from 1760 patients under regular follow-up at our outpatient clinics. Of the 152 patients included in the analysis (cases and controls), 96 (63.2%) were male, and 124 (81.6%) had Crohn's disease. Median age at TB diagnosis was 39.5 [interquartile range (IQR) 30.8-56.3]. Half of the active TB cases were disseminated (50%). Overall, 36 patients with TB (94.7%) were being treated with immunosuppressive medications. Of those, 31 (86.1%) were under anti-TNF drugs. Diagnosis of TB occurred at a median of 32 months after the first dose of anti-TNF (IQR 7-84). In multivariate analysis, IBD diagnosis older than 17 years and anti-TNF therapy were significantly associated with the development of TB (p < 0.05). After the TB treatment, 20 (52.7%) patients received anti-TNF therapy, and only one developed 'de novo' TB 10 years after the first infection.

Conclusions

TB remains a significant health problem in IBD patients from endemic regions, especially those treated with anti-TNFs. In addition, age at IBD diagnosis (>17 years old) was also a risk factor for active TB. Most cases occur after long-term therapy, suggesting a new infection. The reintroduction of anti-TNFs agents after the anti-TB treatment seems safe. These data highlight the importance of TB screening and monitoring in IBD patients living in endemic areas.

Efficacy of Early Optimization of Infliximab Guided by Therapeutic Drug Monitoring during Induction-A Prospective Trial

Therapeutic drug monitoring (TDM) during induction therapy with anti-tumor necrosis factor drugs has emerged as a strategy to optimize response to these biologics and avoid undesired outcomes related to inadequate drug exposure. This study aimed to describe clinical, biological, and endoscopic remission rates at six months in Brazilian inflammatory bowel disease (IBD) patients following a proactive TDM algorithm guided by IFX trough levels (ITL) and antibodies to IFX (ATI) levels during induction, at week six. A total of 111 IBD patients were prospectively enrolled, excluding those previously exposed to the drug. ITL ≥ 10 μg/mL was considered optimal. Patients with suboptimal ITL (<10 µg/mL) were guided according to ATI levels. Those who presented ATI ≤ 200 ng/mL underwent dose intensification in the maintenance phase, and patients with ATI > 200 ng/mL discontinued IFX. In our study, proactive TDM was associated with persistence in the IFX rate at six months of 82.9%. At that time, rates of clinical, biological, and endoscopic remission in patients under IFX treatment were 80.2%, 73.9%, and 48.1%, respectively. Applying a simplified TDM-guided algorithm during induction seems feasible and can help improve patients' outcomes in clinical practice.

Nutritional Global Status and Its Impact in Crohn's Disease

Background

Malnutrition among inflammatory bowel disease (IBD) subjects is well documented in literature and may emerge from factors including inadequate dietary intake, malabsorption and disease activity. The aim of this study was to complete a comprehensive nutrition assessment and explore what possibilities may help bring a better quality of life for IBD subjects.

Methods

Nutritional status based on biochemical tests, body composition and body mass index (BMI). Food intake was assessed by an alternate 3-day food record and the adequacy of intake was evaluated according to national and international references. Clinical disease activity was evaluated by the Harvey-Bradshaw index and CRP levels.

Results

The study included 217 patients and 65 controls, where 54.4% of these patients were classified as normal weight with a mean BMI lower than controls (23.8 ± 4.9 versus 26.9 ± 4.8 kg/m², P = 0.02). Patients with disease activity showed more overweight and obesity than patients with controlled disease. Vitamin B12 deficiency was present in 19% of Crohn’s disease (CD), mainly in patients with ileal commitment and small bowel resections. Anemia was present in 21.7% of patients, being more common in patients with active disease (25%) and bowel resection (23%). Regarding calorie intake (EI), CD group ingested more than controls (1986.3 ± 595.9 kcal versus 1701.8 ± 478.9 kcal; P = 0.003).

Conclusions

CD patients presented micronutrient deficiency when compared with controls, explained for other reasons than intake restrictions. Also, fat excess might have contributed to disease burden as continuously reported in the literature.

Eye disorders in patients with celiac disease and inflammatory bowel disease: A study using clinical data warehouse

BACKGROUND AND AIM

To analyze the prevalence of ophthalmic manifestations in patients with celiac disease, Crohn's disease and ulcerative colitis in Munich/Germany.

METHODS

A total of 272,873 patients of Ludwig Maximilians Universitat Ophthalmological Hospital with eye disease were evaluated between 2003 and 2019. The International Classification of Diseases, 10th revision (ICD-10) of celiac disease Crohn's disease, ulcerative colitis, and all medical records which had the diagnosis of these diseases were analyzed.

RESULTS

A total of 272,873 patients were analyzed, with a mean age of 53 years, with approximately 48% female patients, and 51% male patients. We selected 72 patients with celiac disease (68% women and 32% men), with a minimum age of 8 years, maximum of 103 years, and an average of 52 years. The most common diagnoses were dry eye (32%) and cataract (12%). The mean intraocular pressure of patients with celiac disease was 15 mmHg. During the same study period, 103 patients with Crohn's disease were analyzed, with an average intraocular pressure of 14 mmHg.The minimum age of the patients was 12 years and a maximum of 93 years with an average age of 55 years, with 57% of females and 43% of males. The most common diagnoses were cataract (22%) and dry eye (19%). During the same study period, 99 patients with ulcerative colitis were analyzed, with an average intraocular pressure of 14 mmHg.The minimum age of the patients was 6 years and a maximum of 96 years, with an average age of 61 years, with 36% of females and 64% of males. The most common diagnoses were cataract (29.2%) and dry eye (12%).

CONCLUSIONS

The main ophthalmological manifestations of patients requiring eye follow-up were dry eye and cataract for all the diseases analyzed, which can be considered as coincident complications. None of the three diseases had increased intraocular pressure. Thus, celiac disease presented a profile of ophthalmological manifestation similar to the other intestinal inflammatory diseases studied.

Endoscopic activity, tissue factor and Crohn's disease: findings in clinical remission patients

BACKGROUND

As Crohn's disease (CD) is associated with a high risk of thromboembolic events (TE), including patients with subclinical inflammation, we aim to evaluate the correlation between the impact of endoscopic activity (EA) in the coagulation profiling of CD patients while in clinical remission.

METHODS

From 164 consecutive CD patients included in clinical remission [Crohn's disease activity index (CDAI) < 150], 75 were in the EA group [Simplified Endoscopic Score for CD (SES-CD) ⩾ 7], 89 were in the endoscopic remission (ER) group (SES-CD ⩽ 2), and 50 were included as healthy controls in the study. Blood samples were analyzed for tissue factor (TF), factor VIII (FVIII), thrombomodulin (TM), ADAMTS-13, von Willebrand factor (VWF), and endogenous thrombin potential (ETP), as well as collecting data regarding risk factors for TE and CD profile.

RESULTS

Mean plasma TF activity showed significantly higher levels in the EA group when compared with the ER and control groups (127 pM versus 103 pM versus 84 pM; p = 0.001), although the VWF:Ag (160% versus 168% versus 110%; p = 0.001), VWF/ADAMTS-13 (191 versus 219 versus 138; p = 0.003), FVIII (150% versus 144% versus 90%; p = 0.001) and TM (5.13 ng/ml versus 4.91 ng/mL versus 3.81 ng/ml; p < 0.001) were only increased in CD regardless of EA status when compared with controls. Lastly, ETP with and without TM remained the same in all three groups.

CONCLUSIONS

CD patients in clinical remission with EA present endothelial lesion inducing TF exposure and subsequent coagulation cascade activation. Recommended thromboprophylaxis for EA outpatient subgroups will require additional investigation in order to be validated.

Recovery from COVID-19 Pneumonia in a Patient with Acute Severe Colitis

Introduction

The coronavirus disease 2019 (COVID-19) pandemic has increased concern regarding SARS-CoV-2 infection in inflammatory bowel disease (IBD) patients, especially those on immunosuppressive therapies or with active disease. There are limited reports describing the clinical features of COVID-19 in an IBD population, and the impact of immunosuppression on the severity of the infection remains unclear.

Case Report

A 33-year-old female patient with a long history of ulcerative colitis, poorly controlled, was admitted with COVID-19 a few days after being discharged from the hospital for treatment of acute severe ulcerative colitis. High-risk factors for COVID-19 complications, i.e., high-dose steroids (40 mg prednisone) and severe active disease, were present at admission. Despite the development of extensive pulmonary involvement, the patient had a favorable outcome.

Discussion

Management of IBD patients during the COVID-19 pandemic has been challenging. Measures to minimize the potential risk of SARS-CoV-2 infection, including strict social distancing and self-isolation, in the IBD population have been recommended, especially for high-risk patients. Although steroid tapering and persistence of biologics are advised by professional groups, the best treatment strategy for IBD patients presenting a flare during the outbreak has yet to be defined.

Management of inflammatory bowel disease patients in the COVID-19 pandemic era: a Brazilian tertiary referral center guidance

The world is fighting the COVID-19 outbreak and health workers, including inflammatory bowel diseases specialists, have been challenged to address the specific clinical issues of their patients. We hereby summarize the current literature in the management of inflammatory bowel disease (IBD) patients during the COVID-19 pandemic era that support the rearrangement of our IBD unit and the clinical advice provided to our patients.

Pancreatic endosonographic findings and clinical correlation in Crohn's disease

OBJECTIVES

We aimed to evaluate the incidence of pancreatic alterations in Crohn's disease using endoscopic ultrasound (EUS) and to correlate the number of alterations with current clinical data.

METHODS

Patients diagnosed with Crohn's disease (n=51) were examined using EUS, and 11 variables were analyzed. A control group consisted of patients with no history of pancreatic disease or Crohn's disease. Patients presenting with three or more alterations underwent magnetic resonance imaging (MRI). Pancreatic function was determined using a fecal elastase assay.

RESULTS

Two of the 51 patients (3.9%) presented with four EUS alterations, 3 (5.9%) presented with three, 11 (21.5%) presented with two, and 13 (25.5%) presented with one; in the control group, only 16% presented with one EUS alteration (p<0.001). Parenchymal abnormalities accounted for 39 of the EUS findings, and ductal abnormalities accounted for 11. Pancreatic lesions were not detected by MRI. Low fecal elastase levels were observed in 4 patients, none of whom presented with significant pancreatic alterations after undergoing EUS. Ileal involvement was predictive of the number of EUS alterations.

CONCLUSION

A higher incidence of pancreatic abnormalities was found in patients with Crohn's disease than in individuals in the control group. The majority of these abnormalities are related to parenchymal alterations. In this group of patients, future studies should be conducted to determine whether such morphological abnormalities could evolve to induce exocrine or endocrine pancreatic insufficiency and, if so, identify the risk factors and determine which patients should undergo EUS.

Helminths as an alternative therapy for intestinal diseases

Animal models and clinical studies have shown that helminth infections exert immunomodulatory activity, altering intestinal permeability and providing a potential beneficial action on autoimmune and inflammatory disorders in human beings, such as inflammatory bowel disease (IBD) and celiac disease. This is consistent with the theory that intestinal microbiota is responsible for shaping human immunological responses. With the arrival of the immunobiologic era and the use of antibodies, we propose a distinctive pathway for treating patients with IBD and celiac disease. We have some evidence about the safety and tolerability of helminth use, but evidence about their impact on disease activity is lacking. Using worms to treat diseases could be a possible way to lower treatment costs, since the era of immunobiologic agents is responsible for a significant rise in expenses. Some questions remain to be investigated regarding the use of helminths in intestinal disease, such as the importance of the specific species of helminths used, appropriate dosing regimens, optimal timing of treatment, the role of host genetics, diet, environment, and the elucidation of the exact mechanisms of action. One promising approach is the use of helminth-derived anti-inflammatory molecules as drugs. Yet there are still many challenges with this method, especially with regard to safety. Studies on intestinal permeability point to Strongyloides stercoralis as a useful nematode for these purposes.

Inter- and intraobserver agreement in computed tomography enterography in inflammatory bowel disease

AIM

To evaluate intra- and interobserver agreement in imaging features in inflammatory bowel disease and comparison with fecal calprotectin (FC) levels.

METHODS

Our institutional computed tomography enterography (CTE) database was retrospectively queried to identify patients who underwent CTE from January 2014 to June 2015. Patient inclusion criteria were confirmed inflammatory bowel disease (IBD) and FC collected < 4 mo after CTE without any change in clinical treatment or surgical treatment during this interval. The exclusion criterion was poor image quality. Two blinded abdominal radiologists, with 12 and 3 years of experience analyzed the CTE regarding localization (small bowel, colonic, both, or no disease detected); type of IBD (inflammatory, stenosing, fistulizing, > 1 pattern, or normal); and signs of active disease (present or absent). In 42 of 44 patients evaluated, routine CTE reports were made by one of the readers who re-evaluated the CTEs ≥ 6 mo later, to determine the intraobserver agreement. FC was considered a sign of disease activity when it was higher than 250 μg/g.

RESULTS

Forty-four patients with IBD (38 with Crohn’s disease and 6 with ulcerative colitis) were included. There was a moderate interobserver agreement regarding localization of IBD (κ = 0.540), type of disease (κ = 0.410) and the presence of active signs in CTE (κ = 0.419). There was almost perfect intraobserver agreement regarding localization, type and signs of active disease in IBD. The κ values were 0.902, 0.937 and 0.830, respectively. After a consensus between both radiologists regarding inflammatory activity in CTE, we found that 24 (85.7%) of 28 patients who were classified with active disease had elevated FC, and six (37.5%) of 16 patients without inflammatory activity in CTE had elevated FC (P = 0.003). The correlation between elevated FC and the presence of active disease in CTE was significant (κ = 0.495, P = 0.001).

CONCLUSION

We found almost perfect intraobserver and moderate interobserver agreement in the signs of active disease in CTE with concurrence of high FC levels.

Ophthalmologic manifestations of celiac disease

Celiac disease is an autoimmune disorder that affects the small intestine of genetically predisposed individuals. Ophthalmic manifestations are within the extra-intestinal manifestations, and can be divided into those of autoimmune disorders or those due to absorptive disabilities. This article reviewed the ophthalmologic manifestation of celiac disease. Ophthalmic symptoms are rare, but should be investigated in patients with celiac disease and taken into consideration as the first systemic manifestation.

A snapshot of the nutritional status of Crohn's disease among adolescents in Brazil: a prospective cross-sectional study

BACKGROUND

The relationship between nutrition and Crohn's disease (CD) is complex and involves several therapeutic possibilities including: nutrition treatment for malnourished patients, optimization of growth and development, prevention of osteoporosis, first-line therapy for active disease, and maintenance of disease remission. In children and adolescents with CD, malnutrition is a common problem that adversely affects the prognosis. In at-risk adolescent CD patients, it is important to assess body composition, food intake, energy expenditure, nutrient balance and serum levels of nutrients before planning interventions for this population. The aim of this study was to provide a snapshot of the nutritional status of adolescents with CD in Brazil.

METHODS

We prospectively selected 22 patients with mildly to moderately active CD, 29 patients with inactive CD and 35 controls (first-degree relatives of and in the same age bracket as the CD patients). The age range of participants was between 13.2 and 19.4 years old. We collected anthropometric data including weight, height, and body mass index (BMI), which were expressed as Z scores: weight-for-age, height-for-age and BMI-for-age, respectively, as well as using bioimpedance to determine body composition and assessing the Tanner stage. We also assessed macronutrients and micronutrients (serum levels and dietary intake of both). We used the chi-square test to determine whether any of the studied variables were associated with inactive or active CD. The level of significance was set at 5 % (p < 0.05). We have written informed parental consent for participation for any minors and written informed consent for any participants that were adults.

RESULTS

The mean values for lean body mass, Tanner stage, height-for-age Z score and BMI-for-age Z score were lower in the active CD group than in the inactive CD and control groups (p < 0.05 for both). Compared with the controls, the CD patients showed significant differences in terms of the quality of dietary intake (particularly in caloric intake, dietary protein intake, dietary fiber intake, and micronutrient intake), which were reflected in the serum levels of nutrients, mainly vitamins A and E (p < 0.05).

CONCLUSIONS

Adolescents with CD (including those with mildly to moderately active or inactive disease) have a nutritional risk, which makes it important to conduct nutritional assessments in such patients.

Cytomegalovirus infection in inflammatory bowel disease is not associated with worsening of intestinal inflammatory activity

Background

Cytomegalovirus is highly prevalent virus and usually occurs in immunocompromised patients. The pathophysiology and treatment of inflammatory bowel disease often induce a state of immunosuppression. Because this, there are still doubts and controversies about the relationship between inflammatory bowel disease and cytomegalovirus.

Aim

Evaluate the frequency of cytomegalovirus in patients with inflammatory bowel disease and identify correlations.

Methods

Patients with inflammatory bowel disease underwent an interview, review of records and collection of blood and fecal samples. The search for cytomegalovirus was performed by IgG and IgM blood serology, by real-time PCR in the blood and by qualitative PCR in feces. Results were correlated with red blood cell levels, C-reactive protein levels, erythrocyte sedimentation rates and fecal calprotectin levels for each patient.

Results

Among the 400 eligible patients, 249 had Crohn's disease, and 151 had ulcerative colitis. In the group of Crohn's disease, 67 of the patients had moderate or severe disease, but 126 patients presented with active disease, based on the evaluation of the fecal calprotectin. In patients with ulcerative colitis, only 21 patients had moderate disease, but 76 patients presented with active disease, based on the evaluation of the fecal calprotectin. A large majority of patients had positive CMV IgG. Overall, 10 patients had positive CMV IgM, and 9 patients had a positive qualitative detection of CMV DNA by PCR in the feces. All 400 patients returned negative results after the quantitative detection of CMV DNA in blood by real-time PCR. Analyzing the 19 patients with active infections, we only found that such an association occurred with the use of combined therapy (anti-TNF-alpha + azathioprine)

Conclusion

The findings show that latent cytomegalovirus infections are frequent and active cytomegalovirus infection is rare. We did not find any association between an active infection of CMV and inflammatory bowel disease activity.

Titanium dioxide induced inflammation in the small intestine

AIM: To investigate the effects of titanium dioxide (TiO₂) nanoparticles (NPTiO₂) and microparticles (MPTiO₂) on the inflammatory response in the small intestine of mice.

METHODS: Bl 57/6 male mice received distilled water suspensions containing TiO₂ (100 mg/kg body weight) as NPTiO₂ (66 nm), or MPTiO₂ (260 nm) by gavage for 10 d, once a day; the control group received only distilled water. At the end of the treatment the duodenum, jejunum and ileum were extracted for assessment of cytokines, inflammatory cells and titanium content. The cytokines interleukin (IL)-1b, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, IL-17, IL-23, tumor necrosis factor-α (TNF-α), intracellular interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) were evaluated by enzyme-linked immunosorbent assay in segments of jejunum and ileum (mucosa and underlying muscular tissue). CD4⁺ and CD8⁺ T cells, natural killer cells, and dendritic cells were evaluated in duodenum, jejunum and ileum samples fixed in 10% formalin by immunohistochemistry. The titanium content was determined by inductively coupled plasma atomic emission spectrometry.

RESULTS: We found increased levels of T CD4⁺ cells (cells/mm²) in duodenum: NP 1240 ± 139.4, MP 1070 ± 154.7 vs 458 ± 50.39 (P < 0.01); jejunum: NP 908.4 ± 130.3, MP 813.8 ± 103.8 vs 526.6 ± 61.43 (P < 0.05); and ileum: NP 818.60 ± 123.0, MP 640.1 ± 32.75 vs 466.9 ± 22.4 (P < 0.05). In comparison to the control group, the groups receiving TiO₂ showed a statistically significant increase in the levels of the inflammatory cytokines IL-12, IL-4, IL-23, TNF-α, IFN-γ and TGF-β. The cytokine production was more pronounced in the ileum (mean ± SE): IL-12: NP 33.98 ± 11.76, MP 74.11 ± 25.65 vs 19.06 ± 3.92 (P < 0.05); IL-4: NP 17.36 ± 9.96, MP 22.94 ± 7.47 vs 2.19 ± 0.65 (P < 0.05); IL-23: NP 157.20 ± 75.80, MP 134.50 ± 38.31 vs 22.34 ± 5.81 (P < 0.05); TNFα: NP 3.71 ± 1.33, MP 5.44 ± 1.67 vs 0.99 ± 019 (P < 0.05); IFNγ: NP 15.85 ± 9.99, MP 34.08 ± 11.44 vs 2.81 ± 0.69 (P < 0.05); and TGF-α: NP 780.70 ± 318.50, MP 1409.00 ± 502.20 vs 205.50 ± 63.93 (P < 0.05).

CONCLUSION: Our findings indicate that TiO₂ particles induce a Th1-mediated inflammatory response in the small bowel in mice.

Prevalence of celiac disease among blood donors in São Paulo: the most populated city in Brazil

OBJECTIVE

Celiac disease is a permanent enteropathy caused by the ingestion of gluten, which leads to an immunemediated inflammation of the small intestine mucosa. The prevalence of celiac disease varies among different nations and ethnic backgrounds, and its diversity is determined by genetic and environmental factors. São Paulo city is one of the largest cities in the world, with a vast population and an important history of internal migratory flow from other Brazilian regions, as well as immigration from other, primarily European, countries, resulting in significant miscegenation. The aim of the present study was to estimate the prevalence of adults with undiagnosed celiac disease among blood donors of São Paulo by collecting information on the ancestry of the population studied.

METHODS

The prevalence of celiac disease was assessed by screening for positive IgA transglutaminase and IgA endomysium antibodies in 4,000 donors (volunteers) in the Fundação Pró-Sangue Blood Center of São Paulo, São Paulo, Brazil. The antibody-positive subjects were asked to undergo a small bowel biopsy.

RESULTS

Of the 4,000 subjects, twenty-four had positive tests, although both antibody tests were not always concordant. For example, ten subjects were positive for IgA tissue transglutaminase only. In twenty-one positive patients, duodenal biopsies were performed, and the diagnosis of celiac disease was confirmed in fourteen patients (Marsh criteria modified by Oberhuber). In this group, 67% claimed to have European ancestry, mainly from Italy, Portugal and Spain.

CONCLUSION

The prevalence of celiac disease is at least 1:286 among supposedly healthy blood bank volunteers in São Paulo, Brazil.

Performance of two commercial ELISAs for detecting IgA anti-human and anti-guinea pig tissue transglutaminase antibodies

BACKGROUND

Sensitivity and specificity of anti-human tissue transglutaminase antibodies (anti-htTGA) seem to be superior to those of anti-tissue transglutaminase of guinea pig (anti-gptTGA) for screening patients with celiac disease (CD), but there are still controversies. The aim of this study was to evaluate the performance of two INOVA ELISA kits to detect IgA anti-htTGA and anti-gptTGA in patients with and without CD.

METHODS

The study groups were comprised of 49 anti-endomysial antibody (EMA)-positive untreated-CD, and 123 controls (EMA-negative treated CD, EMA-negative chronic diarrhea, autoimmune hepatitis, inflammatory bowel disease and healthy people).

RESULTS

The agreement between the two ELISAs was statistically significant in all study groups and there was no significant difference between them (92.7% agreement; kappa = 0.70; kappa p = 0.001; McNemar p = 1). All patients with serum reactivity of more than 100 units had histologic diagnosis of CD. In seven of 10 patients with treated-CD who had control biopsies, villous atrophy was still present in four who tested positive by both kits. Two of three celiacs with histologic remission tested positive for both anti-tTGA.

CONCLUSIONS

the anti-gptTGA and anti-htTGA determination were equally efficient in identifying patients with untreated-CD with high titers of EMA. Whatever the anti-tTGA ELISA used, the reactivity above 100 units was always related to active CD diagnosed by histologic alterations in intestinal biopsies. The anti-tTGA reactivity by both kits was not only similar in determining histologic activity in the follow-up of CD after a gluten free diet, but also in identifying positive sera from the control groups, regardless if CD has been confirmed by duodenal biopsies.

Oral manifestations of inflammatory bowel disease: a review based on the observation of six cases

Inflammatory bowel disease (IBD) comprises two chronic, tissue-destructive, clinical entities: Crohn's disease (CD) and ulcerative colitis (UC), both immunologically based. Bowel symptoms are predominant, but extra-intestinal complications may occur, including involvement of the oral cavity. Oral involvement during IBD includes several types of lesions: the most common are aphthae; uncommon lesions include, among others, pyostomatitis vegetans and granulomatous lesions of CD. Starting with a presentation of six patients with oral manifestations, which were crucial for the final diagnosis of IBD, a review on the subject is presented. Oral involvement in IBD may be previous or simultaneous to the gastrointestinal symptoms. However, in the majority of cases, bowel disease precedes the onset of oral lesions by months or years. In many patients, the intestinal symptoms may be minimal and can go undetected; thus, most authors believe that the bowel must be thoroughly examined in all patients with suspected IBD even in the absence of specific symptoms. Usually, the clinical course of oral lesions is parallel to the activity of IBD; therefore, oral manifestations are a good cutaneous marker of IBD.

Oral manifestations of inflammatory bowel disease: a review based on the observation of six cases

Inflammatory bowel disease (IBD) comprises two chronic, tissue-destructive, clinical entities: Crohn's disease (CD) and ulcerative colitis (UC), both immunologically based. Bowel symptoms are predominant, but extra-intestinal complications may occur, including involvement of the oral cavity. Oral involvement during IBD includes several types of lesions: the most common are aphthae; uncommon lesions include, among others, pyostomatitis vegetans and granulomatous lesions of CD. Starting with a presentation of six patients with oral manifestations, which were crucial for the final diagnosis of IBD, a review on the subject is presented. Oral involvement in IBD may be previous or simultaneous to the gastrointestinal symptoms. However, in the majority of cases, bowel disease precedes the onset of oral lesions by months or years. In many patients, the intestinal symptoms may be minimal and can go undetected; thus, most authors believe that the bowel must be thoroughly examined in all patients with suspected IBD even in the absence of specific symptoms. Usually, the clinical course of oral lesions is parallel to the activity of IBD; therefore, oral manifestations are a good cutaneous marker of IBD.

Intestinal damage in strongyloidiasis: the imbalance between cell death and proliferation

Strongyloidiasis is an endemic tropical parasitosis caused by Strongyloides stercoralis that also affects immigrants in nontropical countries. The nematode colonizes the duodenum and upper jejunum, inducing mucosal alterations. Because integrity is essential for a functional barrier, we aimed to study apoptosis and proliferation in the small bowel epithelium infected with S. stercoralis. We evaluated 23 patients and 17 controls. Apoptotic cells were detected by TUNEL and M30 immunolabelling, whereas proliferation was scored by Ki67 immunostaining and mitotic counting. Infection increased apoptotic indices in duodenum and jejunum (P < 0.001). Conversely, it decreased cell proliferation in both segments (P < 0.001). Our results showed that intestinal strongyloidiasis promotes an imbalance between cell death and proliferation. This is the first evidence of disruption of the epithelial kinetics with S. stercoralis infection, though the mechanisms remain unclear. Furthermore, our results support the idea that strongyloidiasis disturbs the mucosal integrity and can compromise the intestinal barrier.

Histologic study of colonic mucosa in patients with chronic diarrhea and normal colonoscopic findings

BACKGROUND

There are controversies about the importance of biopsies of normal colon mucosa in the investigation of patients with chronic diarrhea.

STUDY

Colonic and terminal ileum biopsies of 167 patients were reviewed. In 5 patients, used as controls, colonoscopy was done due to family history of colon cancer.

RESULTS

The 5 patients without symptoms had no histologic abnormalities. The histologic findings in 162 patients with chronic diarrhea were as follows: 110 patients (67.9%) with normal histology, microscopic colitis not otherwise specified, and isolated small granulomas; 17 (10.5%) patients had findings of borderline diagnostic significance, including possible collagenous colitis, some features of lymphocytic colitis and melanosis coli; and 35 (21.6%) patients, with diagnostic significant histologic findings as collagenous colitis, lymphocytic colitis, minimal change microscopic colitis, eosinophilic colitis, pericrypt eosinophilic enterocolitis, intestinal spirochetosis, schistosomiasis, and Crohn's disease. Of the 52 patients with either borderline or significant diagnostic abnormalities, in 8 (15.4%) the diagnosis was done only with a proximal study (ascending, transverse, or descending colons).

CONCLUSIONS

Histologic lesions of possible diagnostic value could exist in 32.1% of chronic diarrhea patients with normal colonoscopy, which can justify, in certain cases, mucosa biopsies, which might contribute for a more precise etiologic diagnosis; also, the distribution of these histologic changes has pointed out the importance of having all colon segments biopsied.

Effect of a selective nonsteroidal anti-inflammatory inhibitor of cyclooxygenase-2 on the small bowel of rats

The pathogenesis of nonsteroidal anti-inflammatory drug (NSAID) enteropathy is a complex process involving the uncoupling of mitochondrial oxidative phosphorylation and inhibition of cyclooxygenase (COX). Rofecoxib, a selective inhibitor of COX-2, has shown less gastric damage, but the same beneficial effect is not clear in the case of the small bowel. Fifty-seven male Wistar rats (250-350 g) were divided into three groups (N=19 each) to evaluate the effect of this NSAID on the rat intestine. The groups received 2.5 mg/kg rofecoxib, 7.5 mg/kg indomethacin or water with 5% DMSO (control) given as a single dose by gavage 24 h before the beginning of the experiment. A macroscopic score was used to quantify intestinal lesions and intestinal permeability was measured using [51Cr]-ethylenediaminetetraacetic acid ([51Cr]-EDTA). The extent of intestinal lesion, indicated by a macroscopic score, was significantly lower when rofecoxib was administered compared to indomethacin (rofecoxib=0.0 vs indomethacin=63.6 +/- 25.9; P<0.05) and did not differ from control. The intestinal permeability to [51Cr]-EDTA was significantly increased after indomethacin (control=1.82 +/- 0.4 vs indomethacin=9.12 +/- 0.8%; P<0.0001), but not after rofecoxib, whose effect did not differ significantly from control (control=1.82 +/- 0.4 vs rofecoxib=2.17 +/- 0.4%; ns), but was significantly different from indomethacin (indomethacin=9.12 +/- 0.8 vs rofecoxib=2.17 +/- 0.4%; P<0.001). In conclusion, the present data show that rofecoxib is safer than indomethacin in rats because it does not induce macroscopic intestinal damage or increased intestinal permeability.

Lack of evidence for the pathogenic role of iron and HFE gene mutations in Brazilian patients with nonalcoholic steatohepatitis

The hypothesis of the role of iron overload associated with HFE gene mutations in the pathogenesis of nonalcoholic steatohepatitis (NASH) has been raised in recent years. In the present study, biochemical and histopathological evidence of iron overload and HFE mutations was investigated in NASH patients. Thirty-two NASH patients, 19 females (59%), average 49.2 years, 72% Caucasians, 12% Mulattoes and 12% Asians, were submitted to serum aminotransferase and iron profile determinations. Liver biopsies were analyzed for necroinflammatory activity, architectural damage and iron deposition. In 31 of the patients, C282Y and H63D mutations were tested by PCR-RFLP. Alanine aminotransferase levels were increased in 30 patients, 2.42 1.12 times the upper normal limit on average. Serum iron concentration, transferrin saturation and ferritin averages were 99.4 31.3 g/dl, 33.1 12.7% and 219.8 163.8 g/dl, respectively, corresponding to normal values in 93.5, 68.7 and 78.1% of the patients. Hepatic siderosis was observed in three patients and was not associated with architectural damage (P = 0.53) or with necroinflammatory activity (P = 0.27). The allelic frequencies (N = 31) found were 1.6 and 14.1% for C282Y and H63D, respectively, which were compatible with those described for the local population. In conclusion, no evidence of an association of hepatic iron overload and HFE mutations with NASH was found. Brazilian NASH patients comprise a heterogeneous group with many associated conditions such as hyperinsulinism, environmental hepatotoxin exposure and drugs, but not hepatic iron overload, and their disease susceptibility could be related to genetic and environmental features other than HFE mutations.

Celiac disease in Brazilian adults

Forty-eight adult patients with celiac disease between 15 and 68 years of age (mean, 41 years) were studied. Sixty-seven percent were female and 33% were male patients. Most of the patients were white (98%). The main clinical features were diarrhea (90%), weight loss (70%), and abdominal pain (56%). On physical examination, the main findings were pallor (40%), aphthous stomatitis (31%), and arthralgia (23%). Associated disorders included diabetes mellitus type I, osteoporosis, and atopy (6% each); dermatitis herpetiformis and depression (4% each); and hypothyroidism, hyperthyroidism, duodenal carcinoma, and Gilbert syndrome (2% each). The histologic results according to Marsh criteria (modified by Rostami) are as follows: type I, 10%; type II, 21%; type IIIa, 19%; type IIIb, 17%; and type IIIc, 33%. The sensitivity and specificity for the antiendomysium antibody-immunoglobulin A test were 92% and 100%, respectively, when considering the whole group of patients; however, the sensitivity (but not the specificity) decreased to 86% when taking into account only the group of patients with mild histologic alterations (Marsh type I, II, and IIIa).

CONCLUSION

In general, the authors' results are similar to those described in developing countries, indicating that celiac disease might have the same spectrum of presentation regardless of the region studied.

Intestinal permeability in strongyloidiasis

The objective of the present study was to assess intestinal permeability in patients with infection caused by Strongyloides stercoralis. Twenty-six patients (16 women and 10 men), mean age 45.9, with a diagnosis of strongyloidiasis were evaluated. For comparison, 25 healthy volunteers (18 women and 7 men), mean age 44.9, without digestive disorders or intestinal parasites served as normal controls. Intestinal permeability was measured on the basis of urinary radioactivity levels during the 24 h following oral administration of chromium-labeled ethylenediaminetetraacetic acid ((51)Cr-EDTA) expressed as percentage of the ingested dose. The urinary excretion of (51)Cr-EDTA was significantly reduced in patients with strongyloidiasis compared to controls (1.60 +/- 0.74 and 3.10 +/- 1.40, respectively, P = 0.0001). Intestinal permeability is diminished in strongyloidiasis. Abnormalities in mucus secretion and intestinal motility and loss of macromolecules could explain the impaired intestinal permeability.

Protective effect of metronidazole on uncoupling mitochondrial oxidative phosphorylation induced by NSAID: a new mechanism

BACKGROUND

The pathogenesis of non-steroidal anti-inflammatory drug (NSAID) enteropathy is complex. It involves uncoupling of mitochondrial oxidative phosphorylation which alters the intercellular junction and increases intestinal permeability with consequent intestinal damage. Metronidazole diminishes the inflammation induced by indomethacin but the mechanisms remain speculative. A direct effect on luminal bacteria has traditionally been thought to account for the protective effect of metronidazole. However, a protective effect of metronidazole on mitochondrial oxidative phosphorylation has never been tested.

AIMS

To assess the protective effect of metronidazole on mitochondrial uncoupling induced by indomethacin and also on the increased intestinal permeability and macroscopic damage.

MATERIAL AND METHODS

The protective effect of metronidazole was evaluated in rats given indomethacin; a macroscopic score was devised to quantify intestinal lesions, and intestinal permeability was measured by means of (51)Cr-ethylenediaminetetraacetic acid. The protective effect of metronidazole against mitochondrial uncoupling induced by indomethacin was assessed using isolated coupled rat liver mitochondria obtained from rats pretreated with metronidazole or saline.

RESULTS

Metronidazole significantly reduced the macroscopic intestinal damage and increase in intestinal permeability induced by indomethacin; furthermore, at the mitochondrial level, it significantly reduced the increase in oxygen consumption in state 4 induced by indomethacin and caused less reduction of the respiratory control rate.

CONCLUSION

Our study confirmed the beneficial effects of metronidazole on intestinal damage and intestinal permeability, and demonstrated, for the first time, a direct protective effect of metronidazole on uncoupling of mitochondrial oxidative phosphorylation caused by NSAIDs.

Ursodeoxycholic acid does not interfere with in vivo Helicobacter pylori colonization

A low frequency of Helicobacter pylori in the gastric mucosa of patients with alkaline gastritis has been reported. At the same time, it can be noted that the growth of bacteria can be inhibited by bile acids. We studied 40 patients with chronic gastritis related to Helicobacter pylori in order to determine the effect of ursodeoxycholic acid on this infection. Diagnoses of the infection and the inflammatory process were obtained by histologic study of gastric biopsies collected during endoscopy. Two groups were studied: group I received ursodeoxycholic acid - 300 mg/day, and group II received the placebo, twice a day, both for 28 days. The colonization by Helicobacter pylori and the intensity of the mononuclear and polymorphonuclear inflammatory infiltrate were determined before (time 1) and after (time 2) treatment. Ursodeoxycholic acid had no effect on the Helicobacter pylori infection. A significant reduction in the intensity of the mononuclear inflammatory infiltrate of the gastric antrum mucosa was observed in patients from group I, when we compared not only times 1 and 2 but also groups I and II. However, this was not the case with the body mucosa. We concluded that ursodeoxycholic acid had no action on the colonization by Helicobacter pylori or on the polymorphonuclear inflammatory infiltrate, but it caused a significant reduction in the intensity of the mononuclear inflammatory infiltrate of the gastric antrum.

Gallbladder hypokinesia in Crohn's disease

For the purpose of shedding some light upon the possible mechanisms involved in gallstone formation in patients with Crohn's disease, we have investigated gallbladder emptying by means of ultrasonography in two groups of subjects: controls (n = 40) and Crohn's disease (n = 30). Diminished gallbladder emptying after a liquid fatty-meal stimulus was observed in patients with Crohn's disease when compared with controls (p < 0.001). Also, the values for the residual gallbladder volume (RGV) and maximal decrease in gallbladder volume (MDGV), both in milliliters and percentage were, respectively, increased (RGV = 9.6 ml) and diminished (MDGV = 14.8 ml; MDGV = 60.9%) in patients with Crohn's disease when compared with controls (RGV = 5.9 ml, p < 0.001; MDGV = 19.9 ml, p = 0.003; MDGV = 77.8%, p < 0.001). Hence, reduced gallbladder emptying with consequent stasis might be a contributory factor to the increased prevalence of gallstones in Crohn's disease.

Effects of colectomy on gallbladder motility in patients with ulcerative colitis

In order to gain insight into the possible mechanisms involved in gallstone formation in colectomized ulcerative colitis patients, we studied gallbladder motility by means of ultrasonography in three groups of subjects: controls (N = 40) and ulcerative colitis patients without (N = 30) and with (N = 20) colectomy. Impaired gallbladder emptying after a liquid fatty meal stimulus was observed in ulcerative colitis patients with colectomy compared with those obtained in ulcerative colitis patients without colectomy and controls (P = 0.001). The maximum percentage of gallbladder emptying also, was significantly lower (59.8%) than those seen in ulcerative colitis patients without colectomy (74.5%) and controls (77.8%) (P = 0.001). Diminished gallbladder emptying with ensuing stasis might be a contributory factor to the increased prevalence of gallstones in colectomized patients.

Reproducibility of the ultrasound method for measurement of gallbladder volume

Gallbladder motility has largely been studied in recent years. Since the ultrasonographic method can be used in gallbladder emptying studies, we investigated the reproducibility of the ultrasound method for measurement of gallbladder volume. The ultrasonographic method was highly reproducible (r = 0.97) and, due to its safeness and lack of use of radioactive agents, it is attractive option for gallbladder motility studies in conditions associated with increased frequency of cholelithiasis.

Measurement of gastric emptying time by real-time ultrasonography in patients with Crohn's disease

In order to gain some insight into the possible influence of gastric emptying on gallbladder hypomotility in patients with Crohn's disease, the gastric emptying time (GET) was measured by means of ultrasonography in 10 healthy controls and 10 patients with Crohn's disease. No significant difference was observed between both mean values for GET studies (GET: controls, 165.0 min +/- 12.8; Crohn, 142.0 min +/- 11.5; p = 0.208) after ingestion of a liquid meal. Thus, the gallbladder hypomotility described in patients with Crohn's disease, after a liquid fatty-meal stimulus, can not be explained by prolonged gastric emptying time.

Experimental evaluation of a model for predicting micellar composition and concentration of monomeric species in bile salt binary mixtures

The critical micellar concentration (cmc) values of some mixed systems containing two bile salts were determined by a maximum pressure bubble method and compared with those derived from a theoretical model developed for nonionic surfactants to assess the applicability of this model to such systems. Some assumptions on which the presumed validity of this model was based are discussed. The following binary mixtures were investigated: sodium chenodeoxycholate with cholate, ursocholate and ursodeoxycholate, either unconjugated or conjugated with taurine and glycine at different mole fractions (0, 0.25, 0.5, 0.75, 1) in 0.15 M NaCl. For these mixtures, experimentally determined data were in good agreement with values predicted by the theoretical model: both the cmc and the surface tension at this concentration of the mixtures were intermediate between those of the two pure bile salts; also, as the total bile salt concentration increased, the mixed micelles became enriched with the bile salt having the highest cmc, whereas the total monomer activity, determined by a potentiometric method employing a bile salt-selective electrode, increased only slightly. To test this model in an in vitro system, surface tension was also measured in ox bile samples that were enriched by 50% with sodium ursodeoxycholate, chenodeoxycholate, or their taurine amidates. The cmc and the surface tension at this concentration of the artificial bile increased when enriched with a bile salt with a cmc higher than that of endogenous salts (e.g. ursodeoxycholate versus taurocholate), whereas the reverse occurred for mixtures enriched with a bile salt with a lower cmc, such as chenodeoxycholate.(ABSTRACT TRUNCATED AT 250 WORDS)

Chylomicron metabolism in experimental cirrhosis and cholestasis

Recently it has been demonstrated that artificial emulsions made of lecithin, cholesterol, cholesteryl-oleate and triolein simulate the metabolism of the natural chylomicra. Artificial-chylomicron delipidation and remnant disappearance from plasma were investigated in rats with carbon tetrachloride-induced hepatic cirrhosis or with cholestasis due to bile-duct ligation. Artificial chylomicra were labelled simultaneously with glyceryl tri [9, 10 (N)-3H] oleate and cholesteryl [1-14C] oleate and injected intra-arterially. Simultaneous chylomicron delipidation and remnant removal by the liver were calculated from the plasma radioactivity decay curves: that of glyceryl tri [9, 10 (N)-3H] oleate signifying the combined delipidation and particle-removal processes, whereas that of cholesteryl [1-14C] oleate representing the particle disappearance rate from plasma. Particle delipidation was increased in cirrhosis and decreased in cholestasis, implying faster and slower lipolysis rates respectively. On the other hand, the remnant removal rate by the liver slowed down in both experimental pathologies.

Protein-losing enteropathy in systemic lupus erythematosus

We describe a 23-year old Brazilian woman with systemic lupus erythematosus and protein-losing enteropathy. Small intestinal biopsy revealed lymphangiectasia. Protein-losing enteropathy responded to corticosteroid therapy and should be suspected in cases of systemic lupus erythematosus with hypoalbuminemia without proteinuria and liver failure. A review of the English literature is presented with comments on pathogenesis.

Small bowel bacterial overgrowth in strongyloidiasis

Small bowel bacterial growth was studied in patients with strongyloidiasis, and the results were compared to controls. We concluded that in strongyloidiasis there is small bowel bacterial overgrowth, and so it should be considered in the pathogenesis of some of the gastrointestinal manifestations and complications of strongyloidiasis.

Bile acids do not regulate the intestinal mucosal cholesterol synthesis: studies in the chronic bile duct-ureter fistula rat model

Control male Wistar rats with intact bile circulation, animals with a bile duct-right ureter fistula, and bile duct-right ureter fistula rats fed taurocholic acid (5.5 mg/day) were maintained on a cholesterol-free pellet diet and pulse labeled subcutaneously with radioactive cholesterol. Bile acid feeding did not interfere with the synthesis of cholesterol by the intestinal mucosa or by the whole body in spite of markedly lowering the production of bile acids. Of the total fecal cholesterol mass in bile fistula animals roughly 25% originated from plasma filtration and 75% was ascribed to local mucosal cholesterol synthesis.

[Salicylic derivatives in the clinical treatment of inflammatory bowel disease: new perspectives]

Sulfasalazine is one of the most used drugs in the clinical management of inflammatory bowel disease. Nevertheless up to 30% of the patients experiment side effects related to the drug and end up having the drug diminished or withdrawn. The new salicylic-derivate compounds emerge as a reliable alternative for these patients. The authors review the new preparations and discuss their characteristics, indications and side effects.

[Chylomicron metabolism in experimental cholestasis]

Cholesterol and triglyceride plasma levels are usually increased in cholestasis. The excess of cholesterol and that of triglyceride are carried in abnormal low-density lipoproteins (LP) named LP-X and beta 2-LP respectively. It has been assumed that chylomicron metabolism is involved in these alterations. To gain insight into the LP disturbances in this pathology, artificial chylomicrons (AC) were prepared in protein-free aqueous solutions containing lecithin, cholesteryl-oleate, cholesterol and triolein. AC were labelled simultaneously with cholesteryl--14C-oleate (14C-CO) and 3H-triolein (3H-TO) and pulse injected intra-arterially in rats subjected to total obstruction of the bile duct for 48 hours and sham-operated rats. Blood was collected at 2-minute intervals during 10 minutes for radioactivity determination. Fractional clearance rates of 3H-TO and 14C-CO were diminished. Since plasma decay of 3H-TO reflects predominantly the rate of lipolysis (L) whereas chylomicron remnant removal (CRR) by the liver is represented by the 14C-CO decay, our data suggest that in cholestasis both L and CRR are defective.

Contribution of plasma protein and lipoproteins to intestinal lymph: comparison of long-chain with medium-chain triglyceride duodenal infusion

In rats with intestinal lymph-fistula and electrolyte and protein losses continuously replaced by I.V. infusion, the plasma to lymph filtration of total protein, albumin, and cholesterol was similar after duodenal infusion of either long-chain (LCT) or medium-chain (MCT) triglyceride. Filtration of cholesterol into intestinal lacteals was also measured after pulsed I.V. administration of 14C-beta-sitosterol as an indirect marker for passage of lipoproteins into the lymph system. During intraduodenal administration of LCT and constant I.V. infusion of 125I-apo high density lipoprotein (HDL), intact plasma HDL appeared in lymph and contributed apo-LP to chylomicron formation. Nevertheless, most lymph apo-LP originated from local mucosal synthesis.

Origin of intestinal lymph cholesterol in rats: contribution from luminal absorption, mucosal synthesis and filtration from plasma

Measurement of cholesterol transport from plasma to intestinal lymph based on i.v. labeling with radioactive beta-sitosterol was validated by the simultaneous i.v. administration of 4-14C-beta-sitosterol and of 1,2-3H-cholesterol to two rats with bile duct, intestinal lymph, duodenum and jugular vein cannulations. In 11 other rats undergoing intestinal lymph duct cannulation, each potential source of lymph cholesterol was determined 2-3 weeks after i.v. pulse administration of 1,2-3H-beta-sitosterol and 4-14C-cholesterol. For this purpose, lymph fat, after an intragastric infusion of cottonseed oil (1900mg), was used as a marker for total cholesterol mass transported into intestinal lymph. In these two experimental groups of rats, namely, in the absence and in the presence of supplemental dietary cholesterol, filtration of cholesterol from plasma to lymph and absorption of cholesterol derived from bile did not change in the presence of exogenous cholesterol. In other words, absorption of cholesterol based on the amount of cholesterol in intestinal lymph by direct measurement was comparable to the level obtained by the isotopic procedure based upon lowering of the lymph/plasma ratio of 4-14C-cholesterol specific activity (d.p.m./mg of cholesterol). Plasma cholesterol appearing in intestinal lymph was transported mainly in lymph lipoproteins at a density below 1.006 (i.e., chylomicrons). Esterification was not necessary for luminal cholesterol absorption under these experimental conditions.