Colonic Eosinophilia: Clinicopathologic Study of Paired Right and Left Colon Biopsies from 276 Patients.

OBJECTIVE: This study evaluated differences in eosinophil (Eos) count in the right colon (RC) and left colon (LC) relative to known clinical and pathologic features. METHODS: H&E slides from 276 subjects with biopsies taken from both RC and LC were reviewed. Eos/mm2 were counted in the area with highest concentration then correlated with clinical and pathologic findings for RC and LC. RESULTS: There were higher numbers of Eos/mm2 in RC than in LC (mean 177 vs 122, respectively p<0.0001), and there was significant positive correlation between Eos numbers in the two locations (r=0.57, p<0.001). In RC, the mean Eos/mm2 was 242 with active chronic colitis, 195 with inactive chronic colitis, 160 in microscopic colitis, 144 in quiescent IBD, and 142 with normal histology (p<0.001), and was higher in males (204 vs 164, p=0.022). In LC, mean Eos/mm2 was 186 with active chronic colitis, 168 with inactive chronic colitis, 154 in microscopic colitis, 82 in quiescent IBD, and 84 with normal histology (p<0.001), and was higher in males (154 vs 107, p<0.001). In biopsies with normal histology, RC showed higher mean Eos/mm2 in Asian patients (228 vs 139, p=0.019), and patients with history of UC (205 vs 136, p=0.004), but was not significantly different in patients with or without irritable bowel syndrome with diarrhea (IBS-D) or history of Crohn's disease (CD). In LC the mean Eos/mm2 was higher in males (102 vs 77, p=0.036), and history of CD (117 vs 78, p=0.007), but was not significantly different in patients with or without IBS-D or history of UC. The number of Eos/mm2 was greater in biopsies performed in the summer than during other seasons of the year. CONCLUSION: The mean number of Eos/mm2 in colorectal biopsies varies significantly by location, histopathologic changes, clinical diagnosis, season, gender and ethnicity. Of particular interest is the association between high Eos/mm2 in RC biopsies with otherwise normal histology and clinical history of UC, and in LC biopsies with clinical history of CD. Additional larger and prospective studies that include normal healthy volunteers are needed to establish a reliable cutoff for the histopathologic diagnosis of eosinophilic colitis, taking into consideration the biopsy site within the colon and rectum, as well as patient gender and ethnicity.Presented in part at the annual American College of Gastroenterology meeting, San Antonio, TX October 2019.

The Significance of So-Called Equivocal Immunohistochemical Staining for Cytomegalovirus in Colorectal Biopsies.

CONTEXT.­: Recent studies examining immunohistochemical staining of colorectal biopsies for cytomegalovirus (CMV) reported that some cases showed only occasional small positive nuclei that were called equivocal for CMV. OBJECTIVES.­: To determine the extent and clinical significance of equivocal CMV staining in colorectal biopsies. DESIGN.­: Two-hundred twenty-one consecutive cases of colon and rectal biopsies that were stained for CMV by immunohistochemistry were retrieved from our files and reviewed. Staining results were recorded as negative, unequivocal, or equivocal. Results were correlated with clinicopathologic data, results of polymerase chain reaction studies for CMV, and treatment history. RESULTS.­: Fifty-two cases (24% of all tested, 63% of positive cases) showed equivocal staining for CMV, and of these, 41 had follow-up information. Polymerase chain reaction for CMV was performed largely on blood samples and was not found to be sensitive for the detections of CMV proctocolitis. Of 25 patients who received antiviral treatment, 21 (84%) had complete resolution of symptoms, compared with 8 of 16 (50%) who did not receive antivirals (P = .02). There was no statistically significant difference in response to antiviral drugs in patients with equivocal and unequivocal CMV staining (P = .17). CONCLUSIONS.­: Equivocal CMV staining likely represents true CMV proctocolitis. Prospective studies are needed to confirm these findings.

Pancreatic Acinar Metaplasia in Distal Esophageal Biopsies Is Associated With Chronic Nonsteroidal Anti-inflammatory Drug Use.

CONTEXT.­: The cause of pancreatic acinar metaplasia (PAM) at the distal esophagus/esophagogastric junction is still controversial. Whereas some authors believe it is congenital, others believe it is acquired because of inflammation of the gastric cardia, and more recently it was proposed to be due to chronic proton pump inhibitor use based on a study in rats. OBJECTIVE.­: To determine whether there is correlation between chronic proton pump inhibitor use and PAM in humans. We also investigated the correlation between several clinical and pathologic factors and PAM. DESIGN.­: Four hundred forty-four consecutive biopsies from the distal esophagus/esophagogastric junction were reviewed for the presence of PAM, which was then correlated with several clinical and pathologic findings. RESULTS.­: Pancreatic acinar metaplasia was found in 71 patients (16%). Pancreatic acinar metaplasia was significantly associated with patient age younger than 51 years ( P < .001), chronic carditis ( P = .01), and chronic proton pump inhibitor use ( P = .008). Surprisingly, we also found significant association between PAM and chronic nonsteroidal anti-inflammatory drug use ( P < .001). These associations, including that with chronic nonsteroidal anti-inflammatory drug use, remained significant in multivariate analysis. CONCLUSIONS.­: Our findings confirm the previous reports of significant association between PAM and chronic carditis and the findings from animal studies of association with chronic proton pump inhibitor use. The strong association with chronic nonsteroidal anti-inflammatory drug use has not been previously reported and warrants further studies.

CRM1/XPO1 expression in pancreatic adenocarcinoma correlates with survivin expression and the proliferative activity.

CRM1/XPO1 (CRM1) is a nuclear export chaperone that mediates the export of proteins essential to growth regulation and tumor suppression. Its overexpression in tumors was found to be associated with poor prognosis. Selective inhibitors of nuclear export are in phase I and II clinical trials for several tumor types. Our aim was to investigate CRM1 expression in pancreatic adenocarcinoma (PAC) and its relationship to survivin expression and the proliferative activity. Sections of tissue microarray containing 76 formalin fixed and paraffin embedded PAC were stained by immunohistochemistry (IHC) for CRM1, survivin, and Cyclin A. Expression levels of CRM1 and survivin and the proliferative activity, the S-phase fraction (SPF) in tumor cells, were determined using a quantitative digital image analysis solution (OTMIAS). Sixty-six of the 76 (86%) PAC showed positive staining for CRM1, and 10 (14%) were completely negative. The mean CRM1 expression levels ranged from 0.3 to 53 units and the median from 0.3 to 45 units. There was significant positive correlation between the mean and median expression levels of CRM1 in tumor cells and the mean and median levels of survivin (p<0.001). Moreover, there was positive correlation between the mean and median CRM1 levels in tumor cells and the SPF (p=0.013). Our results show that CRM1 is expressed in a significant proportion of PAC, and increased CRM1 levels correlates with increased survivin levels and increased proliferative activity.