Plasma cells and lymphoid aggregates in sleeve gastrectomy specimens

Abstract

Lymphoid follicles/aggregates in gastric biopsies have been traditionally linked to Helicobacter pylori gastritis, and less commonly to other inflammatory and neoplastic conditions. The frequency of such aggregates in normal stomachs has yet to be adequately evaluated. This is especially relevant when it comes to diagnosing non-specific chronic gastritis in biopsy specimens with chronic inflammation but no evidence of H pylori infection. Sleeve gastrectomies represent an opportunity to study adequately preserved gastric mucosa in patients who are otherwise asymptomatic and lack a history of gastric disease. To study sleeve gastrectomy specimens to quantify the amount of lymphoid follicles/aggregates and lymphocytic infiltration in normal stomachs. Sixty-eight bariatric sleeve gastrectomies and 13 control specimens from Whipple resections were examined for multiple histologic features including type, quantity, and distribution of chronic inflammation and lymphoid follicles/aggregates. Presence of H pylori was documented by both Hematoxylin and eosin-stained (H&E) and immunohistochemistry (IHC). Clinical information including age, sex, medication intake, prior endoscopy, and/or H pylori infection was recorded. The patient population was divided in 2 groups, H pylori negative versus H pylori positive, and statistical analysis was performed by a biostatistician. Two hundred sixty three fundic sections from 68 bariatric patients were examined. Fifty three patients were found to be H pylori-negative, compared with 15 who were positive for H pylori. Among the H pylori-negative group, the average number of lymphoid aggregates was 3.33, compared with an average of 6.26 in the H pylori positive group (the difference was statistically significant with a P-value of .008). The average number of plasma cells per high power field was 2.15 in the H pylori negative group, compared and average of 5.07 in the H pylori positive group (the difference was also statistically significant with a P-value <.001). Clinically, 10 of the 53 H pylori-negative patients had esophagogastroduodenoscopy (EGD) that showed endoscopic mild non-erosive gastric erythema. The remaining had no documentation of symptoms or medication intake, including Non-steroidal anti-inflammatory drugs (NSAIDs) and Proton Pump Inhibitors (PPI). Our results suggest that the presence of lymphoid aggregates and plasma cells infiltration can be a normal finding in otherwise normal gastric mucosa, though more pronounced in H pylori infected patients.

Description of the normal gastric mucosa in anatomy education: How many leukocytes are acceptable?

“…Chen et al (1999) consider the absence of inflammatory cells to be normal. In other studies, the maximal number of plasma cells either alone or combined with lymphocytes per HPF is in the range 2–5 per HPF (Chakhachiro et al, 2020; Dixon et al, 1996; Oberhuber et al, 1996; Pennelli et al, 2020). Small clusters of up to five plasma cells can occur in the normal gastric mucosa (Dayharsh & Burgart, 2001; Figure 2E).…”

“…In the stomach, MALT is always abnormal and configures after an inflammatory process (Zullo et al, 2014) such as H. pylori infection. Lymphoid aggregates with germinal centers suggest active H. pylori infection (Figure 2G) and should therefore always be taken as an abnormal finding (Chakhachiro et al, 2020; Genta et al, 1993; Lash et al, 2015; Odze et al, 2019; Witteman et al, 1995). In children, gastric lymphoid aggregates without germinal centers are not significantly associated with H. pylori infection and can be considered components of the normal gastric lymphoid tissue (Carpentieri et al, 2000), probably related to innate immunity (Yuan & Walker, 2004).…”

“…Some authors also include lymphoid aggregates, predominantly in the antrum (usually located close to the muscularis mucosae at the base of the lamina propria Figure 2C), within their definition of a normal mucosa (Owen, 1986), unless the aggregates represent post‐treatment Helicobacter gastritis. They range from 0.2 to 1.5 mm in longest dimension (Chakhachiro et al, 2020; Genta et al, 1993). As a prime example, lymphocytes and plasma cells in the adjacent aboral intestinal tract are a normal part of “mucosa‐ or gut‐associated lymphoid tissues” (MALT/GALT) forming lymphoid follicles and aggregates (Figure 3).…”

Inflammatory Cell Numbers in the Stomach of Japanese Subjects with Endoscopically Normal Mucosa without Helicobacter pylori Infection

“…Several recent studies have found an association between obesity and gastritis [24, 25]. Chakhachiro et al [26] found markedly few plasma cells (2.15 per high power field [HPF]) in H. pylori -negative stomachs of patients who underwent sleeve gastrectomy for obesity. The present study found no age- or sex-based differences in the number of inflammatory cells, although they are thought to influence the gastric mucosa.…”

Can histopathology of gastric tissue resected in sleeve gastrectomy be informative about serum iron levels?

“…The fact that the presence of lymphoid aggregate detected in all cases and in male cases is associated with low preoperative iron levels in the present study indicates that the role of Helicobacter pylori in this process should be questioned in detail. It is known that lymphoid follicles and / or aggregates are often associated with Helicobacter pylori, but may occasionally be associated with other inflammatory and neoplastic processes (Chakhachiro et al, 2020). Although it is thought that obesity being a low-grade chronic inflammatory condition (Esposito et al, 2003) which may be effective in the formation of lymphoid aggregates, there are also reports that lymphoid clusters that do not contain a germinal center are a normal component of the gastric mucosa without being associated with Helicobacter pylori (Carpentieri et al, 2000).…”