Serum liver fatty acid binding protein shows good correlation with liver histology in NASH.

BACKGROUND/AIMS: Simple, reproducible and non-invasive tests that can be used to determine the severity of non-alcoholic steatohepatitis (NASH) are needed. Liver-type fatty acid binding protein (L-FABP) plays a key role in the fatty acid metabolism of the liver. We aimed to determine whether serum L-FABP levels in patients with NASH were different from those in healthy controls, and if so, whether this was associated with the degree of fibrosis, steatosis and inflammatory activity. METHODOLOGY: Forty-seven patients with histologically confirmed NASH and 41 healthy controls were included in the study. Serum L-FABP levels were measured in all participants. RESULTS: Mean L-FABP levels were significantly higher in patients with NASH compared to the control group (2703.19±1603.47 vs. 1684.58±860.19, p<0.001). Serum L-FABP levels showed a significant positive correlation with NAS score (p=0.03, r=0.312), the degree of fibrosis (p=0.02, r=0.324) and inflammation (p=0.03, r=0.312), BMI (p=0.05, r=0.303), serum ALT (p=0.01, r=0.28), AST (p=0.04, r=0.315), and triglyceride levels (p=0.03, r=0.328). CONCLUSIONS: Serum L-FABP levels are elevated in NASH and this elevation is positively correlated with the degree of fibrosis and inflammation. L-FABP levels may aid as a non-invasive marker in determining the severity of fibrosis and inflammation in patients with NASH.

MEFV gene mutations and its impact on the clinical course in ulcerative colitis patients.

Ulcerative colitis (UC) is an inflammatory disease of the colonic mucosa. The presence of gene responsible for FMF, MEFV, which frequently causes inflammation, may aggravate the clinical course of UC. We aimed to determine the prevalence of MEFV mutations in UC patients and its impact on the clinical course. Four groups were formed as group 1 UC with distal disease, group 2 UC with pancolonic disease, group 3 UC with total colectomy, and group 4 Rheumatoid Arthritis (RA) patients. Eleven mutations of FMF gene were investigated. The mean age of group 1, 2, 3, and 4 were 46.7 ± 13.9, 43.8 ± 12.9, 44.8 ± 14.2, and 45.8 ± 10.9 years, respectively. The mutations were identified in 19 of the 54 UC patients (35.2%). Homozygous E148Q in 2 patients (3.7%) and heterozygous in 17 patients (31.5%) (E148Q 11.1%, M694V 5.6%, V726A 5.6%, K695R 1.8%, M680I 1.8%, and compound heterozygous 5.6%) were determined. Frequencies of MEFV mutations in group 1, 2, and 3 were 30, 27.3, and 58.3%, respectively. The mutations were identified in 3 of the 20 RA patients (15%). All of them were heterozygous. The rate of MEFV mutations were higher in group 3 than in group 4 (P = 0.018), and the number of attacks that were treated with steroid in all UC patients with mutation positive was higher than in mutation negative (P = 0.016). FMF gene mutations may be identified in UC patients up to 58.3%. It may be suggested that the UC patients with severe form should be identified for MEFV mutations before the judgment of colectomy.

Is there any link between oxidative stress and lung involvement due to inflammatory bowel disease: an experimental study.

BACKGROUND/AIMS: Lung involvement due to inflammatory bowel disease (IBD) is frequent, however the pathogenic mechanism is still debatable. Although the evidence of inflammation in colonic and lung tissue has been documented, the possible effect of oxidative stress in lung tissue has not been evaluated to date. We sought to assess the effects of oxidant/antioxidants on lung tissue in a model of experimental colitis. METHODOLOGY: Colitis was induced with intra-colonic administration of 4% acetic acid. Control group received isotonic saline. Serum and lung tissue markers of oxidative stress were explored. RESULTS: Serum total oxidant status was significantly higher in the colitis group than the controls while total antioxidant status was similar. The determinants of oxidants including lipid peroxidation assay and myeloperoxidase activity were significantly higher in the lung tissue of the colitis group whereas the indicators of antioxidant capacity determined as superoxide dismutase, catalase, glutathione and glutathione peroxidase were decreased (p<0.05). CONCLUSIONS: This study showed that oxidative stress is not restricted to the bowel and the lung is a main target of oxidant overload. Pulmonary injury caused by increased oxidant stress may be the underlying reason of pulmonary involvement due to IBD.

Clinical characteristics of inflammatory bowel disease in Turkey: a multicenter epidemiologic survey.

AIM: To investigate the epidemiologic and clinical characteristics of inflammatory bowel disease (IBD) patients in a large multicenter, countrywide, hospital-based study in Turkey. MATERIALS AND METHODS: Twelve centers uniformly distributed throughout Turkey reported through a questionnaire the new IBD cases between 2001 and 2003. The incidence of ulcerative colitis (UC) and Crohn's disease (CD) has been reported per 100,000 people. Epidemiologic features and clinical characteristics of both diseases were analyzed. RESULTS: During the study period, 661 patients of UC and 216 patients of CD were identified. The incidence in the referral population was 4.4/100,000 and 2.2/100,000 for UC and CD, respectively. The age of the patients showed the characteristic biphasic distribution with 2 peaks between 20 and 30 and 50 and 70 years. A male predominance was observed in both diseases. A history of smoking was detected in 15.5% of UC patients and 49.3% of patients with CD. Family history was positive in 4.4% in UC and 8.3% in CD patients. Concomitant amebiasis was observed in 17.3% of patients with UC and 1.3% of patients with CD. A history of appendectomy was reported in 15% of patients with CD and only 3% of patients with UC. Both extraintestinal and local complications were more frequent in CD patients, whereas arthritis was most common in both diseases. CONCLUSIONS: IBDs are frequently encountered in Turkey. IBD incidence is lower than North and West Europe but close to Middle East in our country. The majority of IBD cases are diagnosed in young people (20 to 40 y) with predominance in males. The rate of both intestinal and extraintestinal complications in our population was low when compared with the data reported in the literature. IBD and especially UC, can coexist with amebiasis or become manifest with amebic infestation. The presence of concomitant ameba may create confusion and cause dilemmas in the diagnosis and treatment of UC.

Blastocystis subtypes in irritable bowel syndrome and inflammatory bowel disease in Ankara, Turkey.

Blastocystis infection has been reported to be associated with irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and chronic diarrhoea. The availability of data on the subtypes of Blastocystis found in these patient groups would be of interest in understanding the significance of Blastocystis infection in chronic illness. In this study, we identify Blastocystis subtypes found in patients presenting with IBS, IBD, chronic diarrhoea and asymptomatic patients in Ankara, Turkey. Blastocystis was detected in 11 symptomatic patients by microscopy and 19 by stool culture. Stool culture was more sensitive than microscopy in identifying Blastocystis. Using standard nomenclature adopted in 2007, Blastocystis sp. subtype 3 was the most common in all groups, followed by Blastocystis sp. subtype 2. Identical subtypes of Blastocystis are found in patients with IBS, IBD and chronic diarrhoea. These particular subtypes show low host specificity and are carried by humans and some farm animals. The subtypes of Blastocystis that are commonly found in rodents and certain wild birds were not found in these patients. We suggest a model in which the severity of enteric protozoan infection may be mediated by host factors.

Cerebral sinus thrombosis in a patient with active ulcerative colitis and double heterozygosity for Factor V Leiden and prothrombin gene mutations.

Inflammatory bowel diseases are associated with increased risk for thrombotic complications, In patients with ulcerative colitis (UC) cerebral sinus venous thrombosis (CSVT) is an extremely rare complication. We report a patient with active UC and CSVT. The patient was heterozygous for Factor V Leiden and G20210A prothrombin gene mutations without other identifiable precipitating factors. This patient highlights the need for investigating the patients with UC with thrombotic complications for other thrombophilic states.

Does the urinary excretion of alpha1-microglobulin and albumin predict clinical disease activity in ulcerative colitis?

INTRODUCTION: There remains some difficulty in determining disease activity during the development of inflammatory bowel disease (IBD). The excretion levels of some inflammatory response molecules increase as a result of the onset of this disease. We studied urinary alfa-1-microglobulin (alpha1-MG) and albumin levels in patients with active and inactive ulcerative colitis (UC) and investigated whether we could use these parameters as an activity index. METHODS: The study was carried out at Gazi University Faculty of Medicine, Nephrology and Gastroenterology Departments, between December 2003 and March 2006. In total, 35 patients (male/female: 16/19, mean age: 38.3+/-2.4 years) and 13 healthy controls (male/female: 6/7, mean age: 35.8+/-2.8 years) were enrolled in the study. Nineteen patients had symptoms of active disease and the remaining 16 patients had inactive disease. RESULTS: There was a significant difference in serum C-reactive protein (CRP), urinary albumin excretion, and alpha1-MG excretion levels between patients and controls. Patients with active disease had significantly higher serum CRP and alpha1-MG levels than those with inactive disease and controls. Patients with active disease had higher microalbuminuria levels than inactive patients, but this difference was not statistically significant. Urinary albumin and alpha1-MG excretion did not correlate with serum CRP levels. CONCLUSION: The present study suggests that, as with CRP, urinary levels of albumin and alpha1-MG increase during the active period of UC. During the inactive period, concentrations of these parameters are comparable to controls. The measurement of alpha1-MG and/or microalbuminuria could provide information on disease severity and response to treatment.

Lymphocytic colitis associated with lansoprazole treatment.

INTRODUCTION: There have been several reported cases of lansoprazole-associated collagenous colitis (CC) reported in the literature but only 1 reported case of lansoprazole-associated lymphocytic colitis (LC) in the literature. Both CC and LC are considered inflammatory bowel diseases, but they are distinctly classified based on the condition of the colon, which is typically confirmed through biopsy. CASE SUMMARIES: A 52-year-old white male (Patient 1), with a height of 178 cm and weight of 75 kg, presented to Gazi University Hospital, Ankara, Turkey, with a 3-month history of abdominal pain and nonbloody, watery diarrhea. The patient reported receiving PO lansoprazole 30 mg/d to treat heartburn ~1 week prior to the onset of diarrhea. The patient's medical history revealed that he did not have any preexisting conditions, other than gastroesophageal reflux disease (GERD) for which lansoprazole was prescribed. The medical history report also revealed that the patient was not receiving any concomitant medications or treatments at the time. A colon biopsy confirmed LC. Additionally, a 43-year-old white female (Patient 2), with a height of 168 cm and weight of 61 kg, presented to the same facility with a 6-month history of nonbloody, watery diarrhea and mild lower abdominal cramping. The patient reported that initial onset began ~2 months after receiving a 10-day Helicobacter pylori eradication combination treatment regimen that included lansoprazole, amoxicillin, and clarithromycin, followed by lansoprazole monotherapy to treat GERD. The patient's medical history revealed no other concomitant medications were being adminstered at the time. A colon biopsy confirmed LC. DISCUSSION: A search of the literature using the MEDLINE database and all relevant English-language articles with key words lansoprazole and lymphocytic colitis, found that there were several cases of lansoprazole-associated CC reported and 1 reported case of lansoprazole-associated LC. Histologic findings from laboratory tests and colon biopsies confirmed diagnoses of LC in both patients in this case report. Patient 1 presented with diarrhea and cramping, which the patient reported had been ongoing for ~3 months, following lansoprazole administration. However, after lansoprazole was discontinued, the symptoms completely resolved within 7 days. Patient 2 presented with diarrhea and cramping, which had been occurring for ~6 months. That patient reported that initial onset commenced ~2 months after a 10-day H pylori eradication combination treatment regimen that included lansoprazole, amoxicillin, and clarithromycin, followed by lansoprazole monotherapy to treat GERD. However, after sulfasalazine (3 g/d) was prescribed for 2 months immediately upon diagnosis of LC, there was little improvement in the effort to control the diarrhea in this patient. After omeprazole 20 mg/d was substituted for lansoprazole, the patient's diarrhea ceased. Follow-up sigmoidoscopy 2 months later revealed normal mucosa and complete normalization of histologic findings. The patient remains diarrhea-free while on omeprazole. A causality assessment using the Naranjo adverse reaction algorithm produced scores of 6 for both patients, suggesting that LC was probably associated with lansoprazole treatment. CONCLUSIONS: Here we report 2 cases of LC in patients probably associated with the administration of lansoprazole treatment. Complete remission occurred after lansoprazole was discontinued.

Crohn's colitis with extraintestinal manifestations: a case report.

The etiopathogenesis of inflammatory bowel disease remains unclear, with various extraintestinal features often found with the disease. Sometimes more than one extraintestinal finding is found in the same patient. In this case report, a patient with more than one extraintestinal manifestation of Crohn's disease is presented. Extensive thrombi in the venous system and pyoderma gangrenosum in the left lower extremity was observed but there was complete recovery following treatment with both systemic and topical agents.

Increased plasma levels of advanced oxidation protein products (AOPP) as a marker for oxidative stress in patients with active ulcerative colitis.

BACKGROUND AND AIMS: After NADPH oxidase mediated radical formation, hypochloric acid (HOCl) is formed when Cl is used as a substrate by the myeloperoxidase enzyme. Myeloperoxidase is secreted from H2O2 activated leukocytes with polymorphic nuclei. The generation of HOCl also causes the formation of advanced oxidation protein products (AOPP) through damage to normal tissue and protein oxidation. AOPP has been identified as a marker of inflammation in many diseases. However, AOPP has not been investigated in ulcerative colitis. As a result of mucosal inflammation in ulcerative colitis, oxidative stress can occur. We aimed to determine whether plasma AOPP and oxidative stress markers are detectable in active ulcerative colitis. METHODS: The patient group consisted of 59 patients who were diagnosed with ulcerative colitis in the clinic by histology and endoscopy. The patients were hospitalised and treated in the Gastroenterology Department of Gazi University Medical Facility. The 59 patients were separated into active and inactive groups according to the endoscopic activation index (EAI). Group I consisted of 33 active ulcerative colitis patients, Group II consisted of 26 inactive ulcerative colitis patients and Group III consisted of healthy control subjects. The disease activity of these patients were measured using the Rachmilewitz EAI based on rectosigmoidoscopic or colonoscopic findings. Patients with EAI scores greater than 4 were scored as having active disease (Group I). Patients with EAI<4 were scored as being in disease remission (Group II). The control subjects (Group III) were 51 healthy individuals. The plasma AOPP levels were measured using a spectrophotometric method. RESULTS: There were no statistically significant differences in gender (P<0.22) and age (P<0.11) between the groups examined. The plasma AOPP level in Group I was 148.72±9.08µmol/L. The plasma AOPP level in Group II was 74.48±7.06µmol/L, and the plasma AOPP level in Group III was 64.93±2.55µmol/L. The AOPP levels in Group I were statistically different than in Group II and III (P<0.05). The AOPP levels were similar between Group II and Group III (P>0.05). The EAI value was 8.84±0.31 in Group I and 2.76±0.08 in Group II. There were statistically significant differences for EAI between groups (P<0.05). The correlation between AOPP and EAI in all patients with ulcerative colitis were statistically significant (P<0.05, r=0.61). The regression model in this correlation was statistically significant (y=49.68+10.75x, P<0.05). DISCUSSION: Based on our results, we suggest that AOPP could be used as a non invasive activation marker for ulcerative colitis patients.

A Case of Biliary Pancreatitis Which Subsided after Endoscopic Sphincterotomy during Pregnancy.

A 24-year-old pregnant patient was referred to us because of pain and tenderness in the right upper quadrant. Her liver enzymes and bilirubin levels were elevated; an abdominal ultrasound examination revealed gallstones within the gallbladder. Diagnosis of biliary pancreatitis was established based on elevated amylase levels. Oral intake was withheld; intravenous antibiotic therapy and total parenteral nutrition were administered. An endoscopic sphincterotomy without the use of fluoroscopy was performed. Abdominal pain and elevated serum amylase levels subsided after this procedure. In our case, biliary pancreatitis, which developed during pregnancy, responded well to the endoscopic sphincterotomy, and this procedure obviated the need for surgical intervention and prevented the recurrence of pancreatitis.

Value of fractional exhaled nitric oxide (FE NO) for the diagnosis of pulmonary involvement due to inflammatory bowel disease.

BACKGROUND: Pulmonary involvement due to inflammatory bowel disease (IBD) is frequent when evaluating a patient with IBD and pulmonary involvement remains complicated. Most of the patients are asymptomatic and the methods used are mostly invasive or expensive procedures. The aim of this prospective study is to evaluate the value of the fractional exhaled nitric oxide (FE(NO)) level for the diagnosis of pulmonary involvement due to IBD and to investigate any correlation between FE(NO) level and disease activity. METHODS: Thirty-three nonsmoker patients with IBD (25 ulcerative colitis [UC] and 8 Crohn's Disease [CD]) who were free of corticosteroid treatment and 25 healthy subjects as a control group were enrolled in this study. All patients with IBD were investigated for pulmonary involvement with medical history, physical examination, chest roentgenogram, oxygen saturation, blood eosinophil levels, pulmonary function tests (PFTs), high-resolution computed tomography (HRCT), and FE(NO) level. RESULTS: Pulmonary involvement was established in 15 patients (45.5%) with IBD. The FE(NO) level was higher in patients with pulmonary involvement than without pulmonary involvement and healthy controls independent from the pulmonary symptoms, eosinophil count, duration of disease, activity of disease, and surgery history (FE(NO): 32 +/- 20; 24 +/- 8; 14 +/- 8 ppb, respectively) (P < 0.05). In addition, diffusion capacity (DLCO) was found to be significantly lower in patients with CD compared with UC (P < 0.05). CONCLUSIONS: This study showed that an increased FE(NO) level may be used for identifying patients with IBD who need further pulmonary evaluation.

Comparison of methods for detection of Blastocystis infection in routinely submitted stool samples, and also in IBS/IBD Patients in Ankara, Turkey.

BACKGROUND: This study compared diagnostic methods for identifying Blastocystis in stool samples, and evaluated the frequency of detection of Blastocystis in patients with irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). RESULTS AND DISCUSSION: From a set of 105 stool specimens submitted for routine parasitological analysis, 30 were identified as positive for Blastocystis by the culture method. From that group of 30 positives, Lugol's stain, trichrome staining, and an immunofluorescence assay identified 11, 15, and 26 samples as positive respectively. Using culture as a standard, the sensitivity of Lugol's stain was 36.7%, trichrome staining was 50%, and the IFA stain was 86.7%. The specificity of Lugol's stain was 91%, trichrome staining was 100%, and the IFA stain was 97.3%. In the group of 27 IBS and IBD patients, using all methods combined, we detected Blastocystis in 67% (18/27) of the patients. Blastocystis was detected in 33% (2/6) of IBD patients and 76% (16/21) of IBS patients. For comparison, trichrome staining alone, the method most frequently used in many countries, would have only identified Blastocystis infection in 29% (6/21) of the IBS patients. No parasitic co-infections were identified in the IBS/IBD patients. Most Blastocystis-positive IBS/IBD patients were over 36 with an average length of illness of 4.9 years. CONCLUSIONS: Most IBS patients in this study were infected with Blastocystis. IFA staining may be a useful alternative to stool culture, especially if stool specimens have been chemically preserved.

Rapidly growing giant solitary cavernous hemangioma in a patient with ulcerative colitis.

Cavernous hemangiomas are rare lesions of the colon that usually present with painless, recurrent bleeding. Hemangiomas can be capillary or cavernous type, and 80% of rectal hemangiomas are cavernous type. Ulcerative colitis is an inflammatory disorder that affects the rectum and, occasionally, the whole colon. Diarrhea, rectal bleeding and mucous discharge characterize ulcerative colitis. We present a 61-year-old man with painless rectal bleeding due to a solitary cavernous hemangioma of the rectum. He had been diagnosed with distal type ulcerative colitis in 2003. He was asymptomatic under mesalazine treatment until May 2005, when he presented with new onset bright red rectal bleeding and mucous discharge, despite still defecating normal stools once a day. Rectosigmoidoscopic examination revealed mucosal hyperemia, edema, granularity, and a hyperemic, friable mass lesion 5x4 cm in diameter in the rectum. Following excision, histopathologic examination of the mass was consistent with cavernous hemangioma. There was a six-month period between the rectosigmoidoscopy in which the cavernous hemangioma (5x4 cm in diameter) was detected and the former rectosigmoidoscopy with no reported hemangioma. Thus, this was considered a rapidly growing cavernous hemangioma. Intralesional microhemorrhages may cause rapid enlargement of the hemangiomas. Ulcerative colitis is characterized by inflammation, which may interfere with vascular integrity and augment intralesional microhemorrhage. We postulate that the inflammatory background of ulcerative colitis may have accelerated intralesional hemorrhage and growth of this coincidental rectal cavernous hemangioma. To the best of our knowledge, this is the only case of this sort in the literature.

Esophageal candidiasis and Candida colonization in asthma patients on inhaled steroids.

The aim of this study was to evaluate the risk of esophageal candidiasis in asthma patients who are on inhaled steroids without any other risk factors for esophageal candidiasis by comparing the treatment group with the control group. Moreover, the oropharyngeal and esophageal Candida colonizations were evaluated in the subgroups of both control and treatment groups. Upper gastrointestinal system endoscopic evaluation was performed in 40 asthma patients who were on inhaled steroids for at least 1 month. The control group consisted of 40 steroid naïve patients without asthma. Oral and esophageal samples were obtained for performing quantitative culture. Candida growth in cultures without any clinical signs and symptoms was described as colonization. Candida growth accompanied by clinical signs and symptoms was described as infection. None of the patients in the control group had either esophageal or oropharyngeal candidiasis; however, one (2.5%) asthma patient had esophageal candidiasis and two (5%) asthma patients had oropharyngeal candidiasis. Esophageal and oropharyngeal Candida colonization was determined in 5 (22.7%) and 11 (50%) of the asthma patients and 7 (31%) and 9 (41%) of the control group, respectively. Although the mean numbers of Candida colonies were higher in the asthma group in both localizations, there were no statistically significant differences between the two groups regarding esophageal or oropharyngeal Candida colonization. The risk of esophageal candidiasis due to inhaled steroids is low and inhaled steroids may be used safely in terms of esophageal candidiasis. Future prospective studies are needed to draw more definitive conclusions.

Increased colonic intraepithelial lymphocytes in patients with Hashimoto's thyroiditis.

BACKGROUND: Hashimoto's thyroiditis is an autoimmune thyroid disorder. Lymphocytic colitis and collagenous colitis are characterized by diarrhea with normal endoscopic findings. Autoimmune disorders are common in Hashimoto's thyroiditis and lymphocytic colitis. The aim of this study was to investigate the incidence of lymphocytic colitis in patients with Hashimoto's thyroiditis. STUDY: Fifty patients with well-documented Hashimoto's thyroiditis were included. Twenty patients with nonulcer dyspepsia served as a control group. Five of 50 patients with Hashimoto's thyroiditis reported intermittent diarrhea, whereas no patients had diarrhea in the control group. All patients and the control group underwent total colonoscopy, and multiple colonoscopic biopsies were performed. RESULTS: We found that 40% (20 of 50) of Patients with Hashimoto's thyroiditis had histologic findings consistent with lymphocytic colitis, and one patient in the control group had lymphocytic colitis (p < 0.01). The mean number of intraepithelial lymphocytes was 34.4/100 epithelial cells in these 20 patients, whereas the mean number of intraepithelial lymphocytes was 12.3/100 epithelial cells in the other 30 patients with Hashimoto's thyroiditis (p < 0.05). CONCLUSIONS: There was a higher incidence of histologic findings of lymphocytic colitis in patients with Hashimoto's thyroiditis, although most of the patients were clinically asymptomatic. This finding suggests that lymphocytic colitis may have an asymptomatic clinical course and should encourage further clinical investigations to better anticipate the relationship between autoimmune disorders.

Blastocystis subtypes in irritable bowel syndrome and inflammatory bowel disease in Ankara, Turkey

Blastocystis infection has been reported to be associated with irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and chronic diarrhoea. The availability of data on the subtypes of Blastocystis found in these patient groups would be of interest in understanding the significance of Blastocystis infection in chronic illness. In this study, we identify Blastocystis subtypes found in patients presenting with IBS, IBD, chronic diarrhoea and asymptomatic patients in Ankara, Turkey. Blastocystis was detected in 11 symptomatic patients by microscopy and 19 by stool culture. Stool culture was more sensitive than microscopy in identifying Blastocystis. Using standard nomenclature adopted in 2007, Blastocystis sp. subtype 3 was the most common in all groups, followed by Blastocystis sp. subtype 2. Identical subtypes of Blastocystis are found in patients with IBS, IBD and chronic diarrhoea. These particular subtypes show low host specificity and are carried by humans and some farm animals. The subtypes of Blastocystis that are commonly found in rodents and certain wild birds were not found in these patients. We suggest a model in which the severity of enteric protozoan infection may be mediated by host factors.