Lymphocytic Disorders of the Gastrointestinal Tract

Abstract

Increased numbers of intraepithelial lymphocytes (lymphocytosis) can be found in the esophagus, stomach, small intestine, and colon in a variety of clinical circumstances. This review, directed at practicing pathologists, portrays the normal resident lymphocyte population in the mucosa of each segment of the digestive tract and discusses the different situations that may result in quantitative or qualitative alterations of intraepithelial lymphocytes. Esophageal lymphocytosis has not been fully characterized and its clinical significance, if any, awaits definition. Thus, this diagnosis is presently discouraged. In the stomach, it is particularly important to exclude Helicobacter pylori infection and celiac sprue before diagnosing lymphocytic gastritis. Duodenal lymphocytic infiltrates, inextricably tied with alterations of the villous architecture of the mucosa, are often caused by gluten sensitivity. However, similar morphologic changes may be caused by a vast array of other conditions that must be carefully considered and excluded. Lymphocytic and collagenous colitis are most often unexplained, but their frequent association with autoimmune conditions or certain medications deserve a thorough investigation in each case. Using a combination of histologic and clinical clues, a cause for the intraepithelial lymphocytic infiltration can be identified in many instances. As some of the associated conditions are amenable to effective treatment, the importance of diligently seeking such associations before resorting to a diagnosis of primary lymphocytosis is emphasized.

Collagenous gastritis: a morphologic and immunohistochemical study of 40 patients

“…To define the lymphocytic gastritis-like pattern, we applied the same criteria which define lymphocytic gastritis, typically cited as at least 25 intraepithelial lymphocytes per high power field. 24 Outside the setting of collagenous gastritis, lymphocytic gastritis has been frequently associated with celiac sprue, H. pylori infection, and more rarely with Crohn's disease, syphilis infection, and Menetrier's disease. 24 Only one patient in our study had concurrent collagenous gastritis and H. pylori infection, and this patient had no significant increase in intraepithelial lymphocytes.…”

“…24 Outside the setting of collagenous gastritis, lymphocytic gastritis has been frequently associated with celiac sprue, H. pylori infection, and more rarely with Crohn's disease, syphilis infection, and Menetrier's disease. 24 Only one patient in our study had concurrent collagenous gastritis and H. pylori infection, and this patient had no significant increase in intraepithelial lymphocytes. Two of the patients with a lymphocytic gastritis-like inflammatory pattern had celiac, one had collagenous sprue in the duodenum, and the remaining two had increased intraepithelial lymphocytes in the duodenum.…”

“…In 5 patients (12%), the intraepithelial lymphocyte density was 425 intraepithelial lymphocytes/100 surface epithelial cells, which is the threshold that is used to define lymphocytic gastritis (eg, Figure 1). 24 Often the intraepithelial lymphocytes were most increased in areas of the gastric biopsy displaying lesser degrees of collagen deposition. Two of these five patients had associated celiac sprue and one had collagenous sprue in the duodenum as well as collagenous colitis but no confirmed celiac.…”

Diarrhoea is not the only symptom that needs to be treated in patients with microscopic colitis

“…Several studies have shown a symptomatic overlap between MC and irritable bowel syndrome (IBS) [7,8], and the combination of these two diseases further impairs gastrointestinal symptoms and psychological well-being [8]. The great overlap between IBS and MC, the fact that 63% of MC patients only have a single attack of diarrhoea, and the wide range of conditions rendering secondary MC, may lead to an inaccurate diagnose-setting [1,3,9]. Regarding inflammatory bowel disease (IBD), a consensus has been stated that requires at least one relapse of the disease before a final diagnosis [10].…”

Lymphocytic Esophagitis

“…A small amount of intraepithelial lymphocytes is normally present in the esophagus [4,5]. A majority of these lymphocytes are CD8 T cells, whereas CD4 are a minority and usually present in the lamina propria.…”