Shahrooz Rashtak

Screening for Celiac Disease in a North American Population: Sequential Serology and Gastrointestinal Symptoms

OBJECTIVES:The prevalence of diagnosed celiac disease is <1 in 2,000 in the United States, but screening studies undertaken in European and other populations have revealed a much higher prevalence. The objective of this study was to determine the prevalence of celiac disease and the utility of screening in the general adult population of a geographically isolated area.METHODS:Serum tissue transglutaminase antibodies (tTG-IgA) were measured in volunteer health-care participants aged ≥18 years at the annual Casper, Wyoming, Blue Envelope Health Fair blood draw. Subjects with positive tTG-IgA tests had their endomysial IgA antibodies checked. Double positives were offered endoscopy with small bowel biopsy. All subjects completed a short gastrointestinal (GI) symptom questionnaire.RESULTS:A total of 3,850 residents of the Natrona County had serologic evaluation for celiac disease, 34 of whom tested positive for both tTG and endomysial antibody (EMA) IgA. Excluding three individuals with previous diagnosis of celiac disease, the overall prevalence of positive celiac serology in this community sample was 0.8%. All 31 subjects were offered a small bowel biopsy. Of the 18 biopsied subjects, 17 (94%) had at least partial villous atrophy. Symptoms that were reported by the fair attendees did not predict positivity.CONCLUSIONS:Screening for celiac disease was widely accepted in this preventative health-care setting. Undiagnosed celiac disease affects 1 in 126 individuals in this Wyoming community. Most were asymptomatic or had atypical presentations. Serologic testing can readily detect this disease in a general population.

Review article: coeliac disease, new approaches to therapy

Coeliac disease is managed by life‐long gluten withdrawal from the diet. However, strict adherence to a gluten‐free diet is difficult and is not always effective. Novel therapeutic approaches are needed to supplement or even replace the dietary treatment.

Distinct Role of Kruppel-like Factor 11 in the Regulation of Prostaglandin E2 Biosynthesis

Kruppel-like factor (KLF) proteins are emerging as key regulators of lipid metabolism, diabetes, and the biosynthesis of immunological cytokines. However, their role in the synthesis of prostaglandins, widely known biochemical mediators that act in a myriad of cell biological processes remain poorly understood. Consequently, in this study a comprehensive investigation at the cellular, biochemical, and molecular levels reveal that KLF11 inhibits prostaglandin E2 synthesis via transcriptional silencing of the promoter of its biosynthetic enzyme, cytosolic phospholipase A2α. Mechanistically, KLF11 accomplishes this function by binding to the promoter via specific GC-rich sites and recruiting the Sin3-histone deacetylase chromatin remodeling complex. Further functional characterization reveals that this function of KLF11 can be reversed by epidermal growth factor receptor-AKT-mediated post-translational modification of threonine 56, a residue within its Sin3-binding domain. This is the first evidence supporting a relevant role for any KLF protein in doing both: transcriptionally inhibiting prostaglandin biosynthesis and its reversibility by an epidermal growth factor receptor-AKT signaling-mediated posttranslational mechanisms.

Clinical and molecular features of young-onset colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer related mortality worldwide. Although young-onset CRC raises the possibility of a hereditary component, hereditary CRC syndromes only explain a minority of young-onset CRC cases. There is evidence to suggest that young-onset CRC have a different molecular profile than late-onset CRC. While the pathogenesis of young-onset CRC is well characterized in individuals with an inherited CRC syndrome, knowledge regarding the molecular features of sporadic young-onset CRC is limited. Understanding the molecular mechanisms of young-onset CRC can help us tailor specific screening and management strategies. While the incidence of late-onset CRC has been decreasing, mainly attributed to an increase in CRC screening, the incidence of young-onset CRC is increasing. Differences in the molecular biology of these tumors and low suspicion of CRC in young symptomatic individuals, may be possible explanations. Currently there is no evidence that supports that screening of average risk individuals less than 50 years of age will translate into early detection or increased survival. However, increasing understanding of the underlying molecular mechanisms of young-onset CRC could help us tailor specific screening and management strategies. The purpose of this review is to evaluate the current knowledge about young-onset CRC, its clinicopathologic features, and the newly recognized molecular alterations involved in tumor progression.

Serology of celiac disease in gluten-sensitive ataxia or neuropathy: Role of deamidated gliadin antibody

The role and relevance of deamidated gliadin antibodies specific for celiac disease in gluten-sensitive ataxia/neuropathy is unknown. We investigated the association of celiac-specific serology with gluten-sensitive ataxia/neuropathy, in patients with and without gliadin-induced enteropathy. 51 patients with unexplained ataxia/neuropathy suspected to have gluten sensitivity were included in the study and their serum celiac-specific markers were measured. Deamidated gliadin-IgA (83% vs. 22%), deamidated gliadin-IgG (50% vs. 3%), tissue transglutaminase-IgA (78% vs. 11%), and anti-endomysial-IgA (70% vs. 0%), were significantly more positive in ataxia/neuropathy patients with celiac disease versus those without enteropathy (P<0.001). Our findings suggest that the serological profile of gluten-sensitive ataxia/neuropathy without intestinal involvement lacks the recognition of deamidated gliadin and tissue transglutaminase epitopes.

Iron Deficiency in Long-Term Parenteral Nutrition Therapy

BACKGROUND Iron is not routinely added to parenteral nutrition (PN) formulations in the United States because of the risk of anaphylaxis and concerns about incompatibilities. Studies have shown that iron dextran in non-lipid-containing PN solutions is safe. Data are limited on iron status, prevalence of iron deficiency anemia (IDA), and efficacy of intravenous iron infusion in long-term home PN (HPN). We aimed to determine the incidence of IDA and to examine the effectiveness of parenteral iron replacement in patients receiving HPN. METHODS Medical records of patients receiving HPN at the Mayo Clinic from 1977 to 2010 were reviewed. Diagnoses, time to IDA development, and hemoglobin, ferritin, and mean corpuscular volume (MCV) values were extracted. Response of iron indices to intravenous iron replacement was investigated. RESULTS Of 185 patients (122 women), 60 (32.4%) were iron deficient. Five patients were iron deficient, and 18 had unknown iron status before HPN. Of 93 patients who had sufficient iron storage, 37 had IDA development after a mean of 27.2 months (range, 2-149 months) of therapy. Iron was replaced by adding maintenance iron dextran to PN or by therapeutic iron infusion. Patients with both replacement methods had significant improvement in iron status. With intravenous iron replacement, mean ferritin increased from 10.9 to 107.6 mcg/L (P < .0001); mean hemoglobin increased from 11.0 to 12.5 g/dL (P = .0001); and mean MCV increased from 84.5 to 89.0 fL (P = .007). CONCLUSIONS Patients receiving HPN are susceptible to IDA. Iron supplementation should be addressed for patients who rely on PN.

Colorectal Cancer with Residual Polyp of Origin: A Model of Malignant Transformation

The majority of colorectal cancers (CRCs) arise from adenomatous polyps. In this study, we sought to present the underrecognized CRC with the residual polyp of origin (CRC RPO +) as an entity to be utilized as a model to study colorectal carcinogenesis. We identified all subjects with biopsy-proven CRC RPO + that were evaluated over 10 years at Mayo Clinic, Rochester, MN, and compared their clinical and pathologic characteristics to CRC without remnant polyps (CRC RPO −). Overall survival and disease-free survival overlap with an equivalent hazard ratio between CRC RPO + and RPO − cases when age, stage, and grade are adjusted. The somatic genomic profile obtained by whole genome sequencing and the gene expression profiles by RNA-seq for CRC RPO + tumors were compared with that of age -and gender-matched CRC RPO − evaluated by The Cancer Genome Atlas. CRC RPO + cases were more commonly found with lower-grade, earlier-stage disease than CRC RPO −. However, within the same disease stage and grade, their clinical course is very similar to that of CRC RPO −. The mutation frequencies of commonly mutated genes in CRC are similar between CRC RPO + and RPO − cases. Likewise, gene expression patterns are indistinguishable between the RPO + and RPO − cases. We have confirmed that CRC RPO + is clinically and biologically similar to CRC RPO − and may be utilized as a model of the adenoma to carcinoma transition.

Time Lapse to Colorectal Cancer: Telomere Dynamics Define the Malignant Potential of Polyps

Objective:Whereas few adenomas become cancer, most colorectal cancers arise from adenomas. Telomere length is a recognized biomarker in multiple cancers, and telomere maintenance mechanisms (TMM) are exploited by malignant cells. We sought to determine whether telomere length and TMM distinguish cancer-associated adenomas from those that are cancer-free.Methods:Tissues were identified as cancer-adjacent polyp (CAP)—residual adenoma contiguous with cancer—and cancer-free polyp (CFP)—adenomas without malignancy. Telomere length, TMM, and expression were measured in 102 tissues including peripheral blood leukocytes (PBLs), normal colon epithelium, adenoma, and cancer (in CAP cases) from 31 patients. Telomere length was measured in a separate cohort of 342 PBL from CAP and CFP patients.Results:The mean differences in telomere length between normal and adenoma were greater in CAP than in CFP cases, P=0.001; telomere length in PBL was 91.7 bp greater in CAP than in CFP, P=0.007. Each 100 bp telomere increase was associated with a 1.14 (1.04–1.26) increased odds of being a CAP, P=0.0063. The polyp tissue from CAP patients had shorter telomeres and higher Telomerase reverse transcriptase (hTERT) expression compared with polyps from CFP patients, P=0.05. There was a greater degree of alternative lengthening of telomere (ALT) level difference in CFP polyps than in CAP polyps. The polyp telomere lengths of aggressive CAPs were significantly different from the polyps of non-aggressive CAPs, P=0.01.Conclusions:Adenomas that progress to cancer exhibit distinct telomere length and TMM profiles. We report for the first time that PBL telomeres differ in patients with polyps that become malignant, and therefore may have clinical value in adenoma risk assessment and management.

Sessile Serrated Polyps and Colon Cancer Prevention

Evidence suggests that up to one fifth of colorectal carcinomas develop from serrated polyps, named for their pattern of colonic crypts, and include the sessile serrated adenoma/polyp (SSA/P) that has malignant potential. SSA/Ps are typically located in the proximal colon and have molecular features of hypermethylation of CpG islands in gene promoters and activating point mutations (V600E) in the BRAF oncogene. Both of these features are seen in sporadic colorectal carcinomas with microsatellite instability (MSI) which is potentially consistent with an origin of these cancers from precursor SSA/Ps. Dysplasia is detected in a subset of SSA/Ps with a high risk of progression to carcinoma. An uncommon serrated polyp is the traditional serrated adenoma that is typically found in the left colon, has a tubulovillous architecture, and frequently harbors mutant KRAS. To date, the epidemiology of these serrated lesions is poorly understood, and limited observational data suggest a potential chemopreventive benefit of nonsteroidal anti-inflammatory drugs. The current primary strategy to reduce the risk of colorectal carcinoma from serrated polyps is to enhance their detection at colonoscopy and to ensure their complete removal. This review provides insight into the epidemiologic, clinical, histopathologic, and molecular features of serrated polyps and includes data on their endoscopic detection and chemoprevention. Cancer Prev Res; 10(5); 270–8. ©2017 AACR.

Peripheral Neutrophil to Lymphocyte Ratio Improves Prognostication in Colon Cancer

Micro‐Abstract Distinction of patients at a higher mortality risk beyond stage‐only prognostication is an active area of cancer research. Preoperative neutrophil to lymphocyte ratio (NLR) correlates with survival outcomes in colorectal cancer. In this study, the predictive value of NLR in 2536 patients with respectable tumors was compared with the American Joint Committee on Cancer and Memorial Sloan Kettering Cancer Center models. NLR improved the prognostication of these staging systems. Background: We studied the role of peripheral neutrophil to lymphocyte ratio (NLR) on survival outcomes in colon and rectal cancer to determine if its inclusion improved prognostication within existing staging systems. Patients and Methods: Disease‐free (DFS) and overall survival (OS) hazard ratios (HRs) of pretreatment NLR were calculated for 2536 patients with stage I to III colon or rectal cancer and adjusted for age, positive/total number of nodes, T stage, and grade. The association of NLR with clinicopathologic features and survival was evaluated and compared with the American Joint Committee on cancer (AJCC) TNM staging and Memorial Sloan Kettering Cancer Center (MSKCC) models. Results: High NLR was significantly associated with worse DFS (HR, 1.36; 95% confidence interval [CI], 1.08‐1.70; P = .009) and OS (HR, 1.65; 95% CI, 1.29‐2.10; P < .0005) in all stages for patients with colon, but not rectal, cancer. High NLR was significantly associated with site‐specific worse prognosis, which was stronger in the left versus right colon; an inverse relationship with grade was found. The impact of high NLR on DFS and OS occurred early, with the majority of deaths within 2 years following surgery. Adjusted HRs for 5‐year and 2‐year outcomes in colon cancer per each additional 2‐unit increase in NLR were 1.15 (95% CI, 1.08‐1.23) and 1.20 (95% CI, 1.10‐1.30), respectively. The addition of NLR enhanced the prognostic utility of TNM (TNM alone vs. TNM + NLR: concordance index, 0.60 vs. 0.68), and MSKCC (MSKCC alone vs. MSKCC + NLR: concordance index, 0.71 vs. 0.73) models for colon cancer patients. Conclusion: NLR is an independent prognostic variable for nonmetastatic colon cancer that enhances existing clinical staging systems.