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- Author or Editor: Albert E. Jergens x
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Objective—
To evaluate lavage analytes as markers of mucosal inflammation in healthy dogs and dogs with inflammatory bowel disease (IBD).
Design—
Case control study.
Animals—
9 healthy dogs and 10 dogs with IBD.
Procedure—
A polyethylene glycol electrolyte solution was administered into the dogs’colons via a rectal balloon catheter prior to colonoscopy. Lavage solution was allowed to remain intraluminally for 30 minutes and then was withdrawn. Lavage supernatant samples were immediately analyzed for total protein, IgG, and nitrite concentrations and myeloperoxidase activity. Mucosal biopsy specimens were obtained from the descending colon and histologically reviewed.
Results—
All dogs with IBD had mild to severe lymphocytic-plasmacytic colitis, whereas 8 of 9 healthy dogs did not have substantial mucosal inflammation. Myeloperoxidase activity was not detected in lavage samples from healthy dogs or dogs with IBD. Total protein concentration was not significantly different between groups. Mean nitrite and IgG concentrations were significantly higher in samples from dogs with IBD (1.83 nmol/ml and 46 mg/dl, respectively), compared with samples from healthy dogs (0.245 nmol/ml and undetectable concentrations, respectively). Severity of lesions was not correlated with nitrite or IgG concentration.
Clinical Implications—
Assay of nitrite and IgG concentrations in colonic lavage fluid Is a simple, objective means of evaluating mucosal inflammation in dogs with IBD. Potential uses include monitoring response to treatment and evaluation of complex cases of chronic intestinal inflammation. (J Am Vet Med Assoc 1997;211:318–321)
Summary
Idiopathic inflammatory bowel disease was the diagnosis for 58 dogs and 26 cats, with signs of persistent gastroenteritis, failed responses to dietary trials, and histologic evidence of cellular infiltrates unrelated to other causes of gastrointestinal tract inflammation. Clinical signs of large intestinal dysfunction, watery diarrhea, vomiting, and anorexia with weight loss were common. Nonspecific hematologic, biochemical, and radiographic abnormalities frequently were observed. Mucosal biopsy specimens, obtained endoscopically, were histologically evaluated for severity of mucosal epithelial damage. Mucosal erythema, friability, enhanced granularity, and ulceration or erosion were the predominant endoscopic lesions. Inflammatory bowel disease lesions of moderate severity predominated in the stomach, duodenum, and colon. Lymphocytic/plasmacytic infiltrates were limited to the lamina propria in biopsy specimens from all regions of the gastrointestinal tract. Inflammatory bowel disease commonly is associated with chronic gastroenteritis in dogs and cats.
Abstract
Objective
To validate use of canine colonic biopsy specimens obtained via endoscopy as a source of mucosal lymphocytes (ML) for flow cytometric analysis.
Sample Population
Mucosal biopsy specimens from 10 adult dogs.
Procedure
Mucosal lymphocyte subsets obtained from excised colon were compared with ML subsets obtained from biopsy specimens obtained by use of an endoscopic forceps (6 dogs). Endoscopic colonic biopsy specimens from 4 other dogs were used to define whether obtained ML were predominantly of intraepithelial or lamina propria origin. Mucosal lymphocytes were isolated and labeled, using commercially available monoclonal antibodies directed against canine cell surface antigens. Lymphocyte subsets (cytotoxic or helper T cells; B cells) were determined by use of flow cytometric analysis.
Results
A large number of viable ML was obtained after dissociation of the colonic epithelium from excised colon (45.5 ± 21.5 × 106) and endoscopic (7.2 ± 3.4 × 106) biopsy specimens. Lymphocyte subsets obtained with both methods were identical for each dog and consisted predominantly of intraepithelial lymphocytes, with some lymphocytes from the lamina propria. Collagenase digestion of excised colon also yielded a large number of viable lymphocytes from the lamina propria (56.7 ± 20.4 × 106), but collagenase digestion of endoscopic biopsy specimens was less rewarding.
Conclusion and Clinical Relevance
A representative sample of viable intraepithelial ML is obtainable from endoscopic biopsy specimens. Flow cytometric analysis, a minimally invasive technique, can be used to study ML of client-owned animals. (Am J Vet Res 1999;60:346-353).
Abstract
Objective—To measure serum calprotectin concentration in dogs with inflammatory bowel disease (IBD) before and after initiation of treatment and evaluate its correlation with a clinical scoring system (canine IBD activity index), serum canine C-reactive protein concentration, and severity of histopathologic changes.
Animals—34 dogs with idiopathic IBD and 139 healthy control dogs.
Procedures—From dogs with IBD, blood samples were collected immediately before (baseline) and 3 weeks after initiation of 1 of 2 treatments: prednisone (1 mg/kg, PO, q 12 h; n = 21) or a combination of prednisone and metronidazole (10 mg/kg, PO, q 12 h; 13). Blood samples were collected once from each of the control dogs. For all samples, serum calprotectin concentration was determined via radioimmunoassay.
Results—Mean serum calprotectin concentrations for dogs with IBD at baseline (431.1 μg/L) and 3 weeks after initiation of treatment (676.9 μg/L) were significantly higher, compared with that (219.4 μg/L) for control dogs, and were not significantly correlated with the canine IBD activity index, serum C-reactive protein concentration, or severity of histopathologic changes. The use of a serum calprotectin concentration of ≥ 296.0 μg/L as a cutoff had a sensitivity of 82.4% (95% confidence interval, 65.5% to 93.2%) and specificity of 68.4% (95% confidence interval, 59.9% to 76.0%) for distinguishing dogs with idiopathic IBD from healthy dogs.
Conclusions and Clinical Relevance—Serum calprotectin concentration may be a useful biomarker for the detection of inflammation in dogs, but the use of certain drugs (eg, glucocorticoids) appears to limit its clinical usefulness.
Abstract
Objectives
To quantitate immunoglobulin-containing cells (IgA, IgG, and IgM) and CD3+ T cells in colonic biopsy specimens obtained from dogs with lymphocytic-plasmacytic colitis (LPC), and to compare lymphocyte and plasma cell populations in dogs with LPC with those in healthy dogs.
Animals
10 healthy dogs and 11 dogs with LPC.
Procedure
Colonic mucosal specimens obtained from healthy dogs and dogs with LPC were stained specifically for IgA-, IgG-, and IgM-containing cells and CD3+ T cells by use of immunoperoxidase techniques. Morphometric analyses were done to quantitate lymphocytes and plasma cells in standardized areas of colonic mucosa. Data analyses allowed determination of mean cell numbers in each dog group, and comparison of mean numbers of lymphocytes and plasma cells between dog groups.
Results
CD3+ T cells predominated in healthy dogs, whereas CD3+ T cells and IgA-containing cells were most numerous in dogs with LPC. In both dog groups, the IgG- and IgM-containing cells were considerably less numerous than the other 2 cell types. Comparison of cell populations between dog groups indicated that IgA- and IgG-containing cells and CD3+ T cells were significantly more numerous in the colonic mucosa of dogs with LPC.
Conclusions
Dogs with LPC have significantly increased numbers of IgA- and IgG-containing cells and CD3+ T cells. These lymphocyte and plasma cell distributions indicate similarities to and differences from such distributions in human beings with inflammatory bowel disease. Results provide a basis for future correlation between histologic stage of disease activity and immunologic findings in dogs with LPC. (Am J Vet Res 1999;60:515-520)
Abstract
Objectives
To quantitate numbers of immunoglobulin (Ig)-containing cells (IgA, IgG, and IgM) and T cells (CD3+, CD4+, and CD8+) in the colonic mucosa of healthy dogs, and to determine whether mean cell numbers differ among colonic regions.
Animals
10 clinically normal young adult mixed-breed dogs.
Procedure
Endoscopically obtained specimens of ascending, transverse, and descending colonic mucosa were stained specifically for IgA, IgG, and IgM heavy chains and T-cell antigens, CD3+, CD4+, and CD8+, using immunoperoxidase techniques. Morphometric analysis, performed by light microscopy, was used to quantitate numbers in these standardized areas of colonic mucosa. Data analysis allowed determination of mean cell numbers in each colonic region, as well as comparison of mean cell numbers among colonic regions.
Results
The CD3+ and CD8+ T cells were the predominant immune cell types in all colonic regions. In the mucosa, CD3+ T cells were significantly (P < 0.05) more numerous than CD8+ T cells, and CD8+ T cells were significantly (P < 0.05) more numerous than CD4+ T cells. The IgA-containing cells were significantly (P < 0.05) more numerous than IgG-containing cells, whereas IgM-containing cells were least numerous (P < 0.05). Differences in mean cell counts among colonic regions were not significant for Ig-containing cells or T cells.
Conclusions
Mean numbers of immune cells did not differ significantly among colonic regions in healthy dogs, although differences existed in mean populations of T cells and Ig-containing cells. The CD3+ and CD8+ T cells were the most numerous immune cell types in colonic mucosa.
Clinical Relevance
These quantitative data provide a basis for study of alterations in populations of mucosal immune cells and their possible contribution to the pathogenesis of gastrointestinal tract disease. (Am J Vet Res 1998;59:552–556)
Abstract
Objective
To investigate the distribution of IgA- and IgG-containing cells and T cells in the villi of duodenal mucosa from healthy dogs and from dogs with inflammatory bowel disease (IBD) or gastroenteritis.
Design
Case-control study.
Animals
28 dogs, grouped according to clinical and histologic criteria: 11 dogs with IBD, 8 dogs with nonspecific gastroenteritis, and 9 healthy dogs.
Procedure
Endoscopic biopsy specimens of duodenal mucosa from each dog were stained specifically for IgA and IgG heavy chains and pan T-cell (CD3) antigen, using immunoperoxidase techniques. Morphometric analysis, performed via an image-analysis system, was used to count IgA- and IgG-containing cells and T cells within paired contiguous villi from each dog.
Results
T cells were the predominant immune cell type in all groups of dogs. Significant differences in the villus distribution of IgA- and IgG-containing cells and T cells were not observed. Healthy dogs had significantly higher T-cell counts than had dogs with IBD or gastroenteritis. Dogs with nonspecific gastroenteritis had a significantly higher concentration of IgA-containing cells than the other groups of dogs had. Significant group differences for IgG-containing cells also were evident, with dogs with IBD having the lowest cell counts.
Conclusions and Clinical Relevance
High concentrations of IgA- and IgG-containing cells and T cells in the villus lamina propria cannot be reliably used to distinguish IBD from other intestinal disorders in dogs. Evaluation of T cells may be the most discriminatory method for differentiating dogs with IBD from clinically normal dogs via examination of intestinal biopsy specimens. (Am J Vet Res 1996; 57:697–704)
SUMMARY
Cardiopulmonary responses were evaluated in 12 dogs undergoing endoscopy (gastroscopy and enteroscopy). Constant endoscopic insufflation was used to distend the stomach and small intestine for 30 minutes in groups of small (< 10 kg; n = 4), medium (10 to 20 kg; n = 4), and large (> 20 kg; n = 4) dogs. Cardiopulmonary measurements within groups prior to gastric distention (preendoscopy) were compared with postendoscopy measurements and with those made during endoscopy. After distending the stomach and small intestine, increased luminal pressure within the body of the stomach and in the descending duodenum (P < 0.05) and increased abdominal girth (P < 0.05) were observed, with the greatest changes in small dogs. Caudal vena cava pressures and mean arterial and pulmonary artery pressures increased (P < 0.05) during endoscopy. Cardiac index varied, with small dogs having greater cardiac index (P < 0.05) during endoscopy, compared with that in medium and large dogs. Minute volume remained unchanged during insufflation, despite a decrease in tidal volume (P < 0.05), because of an increase in respiratory rate (P < 0.05). Arterial blood gas analysis revealed a mild, mixed metabolic/respiratory acidosis in all groups. Although cardiopulmonary changes associated with gastrointestinal tract endoscopy were common, the changes were often small and of little clinical significance.
Objective
To determine whether cytologic examination of exfoliative specimens obtained during endoscopy was as useful as histologic examination of mucosal biopsy specimens for the diagnosis of gastrointestinal tract disease in dogs and cats and to compare the diagnostic accuracy of 2 techniques (brush or touch) in preparing specimens for cytologic examination.
Design
Prospective case series.
Animals
85 dogs and 23 cats.
Procedure
Specimens for cytologic and histologic examination were obtained during routine endoscopic examination of the stomach, small intestine, and colon. A diagnosis was made on the basis of cytologic findings (graded objectively) and compared with the diagnosis on the basis of histologic findings.
Results
The diagnostic accuracy of cytologic examination was high for all 3 organs. Sensitivities, specificities, and predictive values of positive and negative results were > 90% in most instances. The diagnostic accuracy of the brush technique was equal or superior to that of the touch technique for 84% of specimens. The brush technique was most useful in detecting cellular infiltrates in the lamina propria, whereas the touch technique was more likely to detect acute mucosal inflammation. Percentages of false-positive (3.2%) and false-negative (6.9%) cytologic interpretations were low.
Clinical Implications
Endoscopy is safe and requires little time to procure specimens for cytologic examination, which can be obtained concurrently with mucosal biopsy specimens. Cytologic examination of exfoliative specimens obtained during endoscopy is a useful and reliable adjunct to histologic examination of biopsy specimens in the diagnosis of gastrointestinal tract disease in dogs and cats. (J Am Vet Med Assoc 1998;213:1755–1759)