Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Described here is a patient with severe watery diarrhea associated with common variable immunodeficiency. Malabsorption for fat, bile acids, vitamin B12 and xylose was demonstrated, but the patient failed to respond to all the usual therapeutic maneuvers. The diarrhea responded only to high dose steroid therapy. Intestinal perfusion studies showed a hitherto undescribed, presumably acquired, glucose-stimulated water, sodium and chloride secretion in the jejunum and ileum, whereas normal fluid and electrolyte transport occurred from bicarbonate and mannitol solutions. Glucose absorption itself was normal and no hormonal, morphologic or biochemical defect was demonstrated to account for the phenomenon. The patient was also interesting when compared with other patients with common variable immunodeficiency in having normal plasma cells in the intestinal mucosa and an extensive family involvement.
 ...
PMID:Immunodeficiency, malabsorption and secretory diarrhea. A new syndrome. 47 4

49 gay men confirmed to be infected with the human immunodeficiency virus (HIV) and 9 HIV seronegative gay men participated in a pilot study comparing clinical status and enteric parasite load with gastrointestinal structure, function and symptomatology. Cases included 16/49 (33%) men who were CDC stage II, 7/49 (14%) who were CDC stage III, and 26/49 (53%) who were CDC stage IV. The mean CD4-lymphocyte count was 476 +/- 199 (SD)/microliter. The prevalence of enteric parasitic flora was similar in HIV seropositive patients and controls. Seven cases had enteric infection with pathogenic agents including 3 patients with Entamoeba histolytica, and 4 patients with Giardia lamblia, one of whom also had cryptosporidiosis. Other cases were most frequently colonized with Blastocystis hominis (44%) and Endolimax nana (41%) regardless of the HIV clinical status. HIV seropositive patients with enteric parasitic colonization tended to have lower mean levels of serum IgA than cases without parasites. Duodenal morphometric mucosal changes demonstrated a significant decrease in the mean villous height (p < 0.01) with no elongation of the crypt depth in HIV-infected patients with and without diarrhea compared to controls. Despite gastrointestinal symptoms including diarrhea and weight loss being more prevalent in HIV infected individuals than controls, no correlations were found between the presence of particular enteric parasites, gastrointestinal symptomatology, the clinical HIV status of the CD4-lymphocyte count, the malabsorption of D-xylose or morphometric changes in the duodenum.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Absence of an association between enteric parasites in the manifestations and pathogenesis of HIV enteropathy in gay men. The GI/HIV Study Group. 136 Dec 41

A 1.3-kb segment of Escherichia coli DNA containing the regulatory gene, araC, and the promoter of the araBAD operon was amplified by the polymerase chain reaction (PCR) and cloned into pUC18, resulting in plasmid pKB130 that produced the alpha fragment of beta-galactosidase upon addition of L-arabinose (L-ara). A synthetic gene for human immunodeficiency virus (HIV)-1 preprotease was placed downstream of the ara-BAD promoter in pKB130 to create a translational fusion inducible by addition of L-ara. The fusion protein correctly autoprocessed in vivo to yield a mature 99-amino-acid HIV-1 protease, which was found predominantly in inclusion bodies. This material could be refolded to an active form, which was purified to homogeneity. A small fraction of the protease was expressed in vivo as a soluble active form, which allowed the monitoring of expression during fermentation by a rapid and simple whole cell assay employing an HIV-1 protease-specific fluorogenic substrate.
 ...
PMID:High-level expression and purification of mature HIV-1 protease in Escherichia coli under control of the araBAD promoter. 136 41

The AIDS wasting syndrome (AWS) is characterized by > 10% loss of baseline body weight during 6 months and may occur in patients with or without associated chronic diarrhea. To determine whether the presence of small-intestinal malabsorption is associated with the development of AWS in human immunodeficiency virus (HIV)-infected patients with chronic diarrhea, we retrospectively reviewed the results of D-xylose testing performed in the clinical evaluation of 21 consecutive HIV-infected patients with chronic diarrhea. A thorough search for small-intestinal pathogens was performed including upper endoscopy, duodenal biopsy, and aspirate for culture and ova and parasite examination. These studies were negative in all patients except two who were excluded from the study. In the 19 patients with no identifiable pathogens, the 1-h serum D-xylose concentration was significantly lower in patients with AWS than in those without, 8.3 +/- 0.8 versus 23.7 +/- 3.4 mg/dl, respectively, p < 0.001. Urine D-xylose excretion during 5 h was also significantly lower in the group with AWS, although creatinine clearance was similar in the two groups. Patients with AWS were more often refractory to standard antidiarrheal therapy with loperamide or diphenoxylate and carried a poor prognosis (90% mortality at 1 year versus 22% mortality in the group without AWS). These data indicate that small intestinal malabsorption is a major component in the severe wasting seen in some HIV-infected patients with chronic diarrhea. Patients with markedly abnormal D-xylose tests may require more potent antidiarrheal therapy and are expected to have a high mortality as a possible consequence of intestinal dysfunction.
 ...
PMID:D-xylose malabsorption: characteristic finding in patients with the AIDS wasting syndrome and chronic diarrhea. 145 20

The significance of the human immunodeficiency virus (HIV) in the small intestinal lamina propria in patients with the acquired immune deficiency syndrome or conditions related to that syndrome who have chronic diarrhea and malabsorption is unclear. To investigate this issue, upper endoscopy (after a 12- to 16-hour fast) with duodenal biopsy and aspirate was performed in 20 HIV-infected seropositive homosexual men referred for diarrhea of more than 8 weeks duration (Group 2) and in 9 HIV-infected homosexual men referred for dysphagia or dyspepsia with no symptoms of malabsorption (Group 1). All biopsy specimens were examined by light microscopy and immunochemical staining with monoclonal antibody against HIV glycoprotein gp41. Electron microscopy was performed in 18 patients in Group 2 and in all patients in Group 1. Immunogold electron microscopy was used as a confirmatory test for identified HIV particles. In addition, D-xylose absorption was measured in all patients after a 25-g dose of D-xylose with measurement of serum D-xylose concentration 1 hour after the dose and measurement of 5-hour urinary D-xylose excretion. Mean serum D-xylose was 35.4 +/- 4.5 mg/dL in Group 1 and 15.8 +/- 2.3 mg/dL in Group 2 (P less than 0.001), whereas mean urine D-xylose was 5.5 +/- 0.6 g in Group 1 and 2.0 +/- 0.4 g in Group 2 (P less than 0.001). Immunoperoxidase for gp41 was positive in 5 (56%) patients in Group 1 and in 12 (60%) patients in Group 2. Lamina propria HIV viral particles were identified by electron microscopy in both patient groups. Viral particles were seen within and adjacent to the cytoplasm of mononuclear cells and were not present in enterocytes or neuroendocrine cells. There were no significant differences in serum or urine D-xylose tests between patients with and without lamina propria HIV. In addition, lipid accumulation in intercellular spaces near the basolateral membrane of adjacent enterocytes was seen in 33% of patients with chronic diarrhea. These findings suggest that lamina propria HIV is not a direct cause of enteropathy in HIV-infected patients and that lymphatic obstruction may be one pathophysiologic mechanism producing this malabsorptive state.
 ...
PMID:Histopathologic findings of duodenal biopsy specimens in HIV-infected patients with and without diarrhea and malabsorption. 141 28

A longitudinal (10-22 month) evaluation of intestinal symptoms and function was performed in five children with symptomatic human immunodeficiency virus (HIV) infection. All received cotrimoxazole, ketoconazole, and immunoglobulins. A search for enteric pathogens and intestinal function tests were repeatedly performed in all patients. Mild episodes of diarrhea were observed in two children. One had cow's milk protein intolerance. Giardia lamblia was found in an asymptomatic carrier. Evidence for impaired intestinal function was found in all patients. These consisted of positive D-xylose and iron oral loads, increased steatorrhea, increased fecal excretion of alpha 1-antitrypsin, abnormal intestinal permeability, and increased food antibody levels. Our results suggest that severe diarrhea may be uncommon in children with HIV infection receiving antimicrobial prophylaxis, but that the intestinal function is frequently, and often markedly, impaired.
 ...
PMID:Impaired intestinal function in symptomatic HIV infection. 186 78

The nutritional needs of children with human immunodeficiency virus infection are poorly understood. Twenty-eight children with vertically transmitted human immunodeficiency virus infection were evaluated for carbohydrate malabsorption using lactose hydrogen breath tests and d-xylose absorption studies. Lactose malabsorption was a common finding in human immunodeficiency virus-infected children and occurred in 8 of 20 patients who had no identifiable enteric pathogen. Lactose malabsorption occurred at an earlier age in human immunodeficiency virus-infected children than in an age-matched group of 45 symptomatic control children (P = 0.02). However, lactose malabsorption was not associated with higher rates of diarrhea or growth failure. Abnormalities in d-xylose absorption were not significantly associated with either diarrhea or growth failure. However, 39% of d-xylose studies (9 of 23) showed abnormal results and were significantly associated with enteric infections (P = 0.004). Abnormalities in small-bowel morphology were found in 4 of 9 children with growth failure, 3 of whom had an enteric infection and low d-xylose absorption. Lactose hydrogen breath testing and d-xylose testing showed carbohydrate malabsorption in 61% of children (17 of 28). This study demonstrates that human immunodeficiency virus-infected children are at risk for malabsorptive disorders, which are not always related to clinical symptoms. We speculate that human immunodeficiency virus may be directly involved in the development of lactose malabsorption. Carbohydrate malabsorption in human immunodeficiency virus-infected children may not be the only factor responsible for growth failure.
 ...
PMID:Malnutrition and carbohydrate malabsorption in children with vertically transmitted human immunodeficiency virus 1 infection. 201 74

D-Xylose absorption was studied in 12 patients with acquired immunodeficiency syndrome (AIDS) or advanced AIDS-related complex who had had diarrhea for more than 8 weeks, averaged an 11% (range, 3% to 21%) body weight loss during the previous 6 months, and had had negative stool examinations for enteric pathogens. Patients were evaluated by duodenal aspiration and biopsy and received both 25 gm oral and 10 gm intravenous doses of D-xylose. Kinetic analysis of D-xylose absorption was characterized by an absorption rate constant (ka) and a rate constant (ko) reflecting nonabsorptive loss. Extent of D-xylose absorption averaged 18.4% +/- 9.3% (+/- SD) in the 12 patients (normal greater than 60%). Percentage of weight loss during the previous 6 months was negatively correlated with ka (r = -0.69; p = 0.018) in the 11 patients in whom this parameter was reduced but was not correlated with either ko or extent of D-xylose absorption. In these patients with human immunodeficiency virus enteropathy, ka was reduced out of proportion to the minor histologic changes present in the duodenal biopsy specimens.
 ...
PMID:Kinetics of D-xylose absorption in patients with human immunodeficiency virus enteropathy. 206 Feb 52

We examined 19 patients (17 men) with human immunodeficiency virus (HIV) infection and gastrointestinal symptoms to determine whether those symptoms were due to either a gastrointestinal tract infection or a defect in mucosal absorption because of an enteropathy. The erythrocyte folate and serum vitamin B12 levels were within normal limits in all of the patients. The serum ferritin level was elevated in 12. The xylose absorption test results were abnormal in 8 of the 13 patients able to complete the study. None of the duodenal aspirates yielded a pathogen. Light microscopy revealed nonspecific lymphocytic inflammation without infection in the stomach (in seven patients), the esophagus (in five), the duodenum (in two) and the rectum (in two). However, biopsy specimens were positive for Candida albicans in the esophagus (four patients), cytomegalovirus in the esophagus (one) and the rectum (two), Helicobacter pylori in the antrum (two), Treponema infection in the rectum (two) and Mycobacterium avium-intracellulare in the small intestine (one). Only three patients had a normal series of biopsy specimens. All of the patients had similar ultrastructural changes at the epithelial-stromal junction of the antral glands and in the intestinal crypts. We conclude that abnormal biochemical and endoscopic findings are common in HIV-positive patients with gastrointestinal symptoms. Defects in carbohydrate absorption and ultrastructural changes may be responsible for some aspects of HIV enteropathy.
 ...
PMID:Gastrointestinal function and structure in HIV-positive patients. 220 20

Thirty three consecutive patients infected by human immunodeficiency virus type 1 (HIV1) with persistent diarrhoea which remained undiagnosed after microbiological examination of six stool samples and rectal histology were investigated for malabsorption. All had xylose and Schilling tests, distal duodenal biopsy, comprehensive barium studies, microbiological examination of six further stool samples, and repeat rectal histology. A microbiological or histological diagnosis of infection was made in 12 patients (multiple organisms in three). Cryptosporidia were identified on five occasions, cytomegalovirus on four, Giardia lamblia on two, and herpes simplex, Campylobacter jejuni, Salmonella enteritidis, and Entamoeba histolytica once each. No organism was found when weight loss was less than 5 kg or stool volume less than 400 ml/day (n = 9). Pathogens were identified in nine of 13 patients (69%) with weight loss greater than 10 kg and stool volume more than 800 ml/day. Barium studies were normal except for ileal flocculation in two patients with cryptosporidiosis. Evidence for malabsorption existed in 24 patients--impaired xylose absorption (n = 19) and abnormal Schilling test (n = 21). Of the patients with a severely abnormal Schilling test, a pathogen was identified in 11 (79%) (including all five with cryptosporidia, and two of the patients with only moderate diarrhoea and weight loss). A simple scoring system based on degree of weight loss and Schilling test result may help to identify the HIV positive patient with seemingly pathogen-negative diarrhoea in whom further investigations are likely to show a specific cause.
 ...
PMID:Investigation of seemingly pathogen-negative diarrhoea in patients infected with HIV1. 238 12


1 2 3 4 Next >>