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Pai, Rish K.

https://orcid.org/0000-0002-2692-221X

Mayo Clinic

Mayo Clinic in Arizona

Citations 118

A study of thymidylate synthase gene expression as a biomarker for the treatment of esophageal adenocarcinoma.
Beamer, Staci E. , Gatalica, Zoran , Xiu, Joanne , Jaroszewski, Dawn E. , Stanton, Melissa, Pai, Rish K. , Krishna, Murli , Thomas, Mathew , Ross, Helen J. , Thomas, Mathew , Thomas, Mathew , Ho, Thai H.

Journal of Clinical Oncology | September 6, 2018 | Volume: 35 | Issue: 15_suppl | Pages: e15563-e15563

10.1200/jco.2017.35.15_suppl.e15563 Get It

e15563 Background: Expression of thymidylate synthase (TS), a target of fluoropyrimidine-based (5-FU) chemotherapy, has prognostic value in colorectal adenocarcinoma. Its value as a biomarker in treatment of esophageal adenocarcinoma (EAC) is unknown. With widespread adoption of CROSS trial protocol for treatment of EAC, 5-FU is frequently omitted from regimens. We retrospectively analyzed the association between TS protein expression and clinical outcomes in EAC. Methods: TS expression levels were measured by immunohistochemistry in formalin-fixed paraffin-embedded specimens from 35 primary EAC patients from 2 institutions (range 5/2006-1/2016); at time of diagnosis and surgical resection (33 neoadjuvant chemoradiation and 2 surgery alone). TS expression higher than 1+, 5% was read as positive. Mean follow up was 1323 days (range 263-3677). TS expression correlated with treatment response and survival in patients treated with and without 5-FU therapy (log-rank test, Kaplan-Meier method). Results: In the cohort of 35 patients, 21 patients (60%) had pretreatment positive TS expression. Overall survival (OS) for TS negative patients was 1216 days versus 974 days for TS positive (p = 0.15). In the 23 patients treated with 5-FU, TS-negative patients had a trend towards longer overall survival compared to TS-positive patients, mean OS (1272 days versus 743 days, p = 0.08). In the group of 12 patients not treated with 5-FU, 2 patients showed negative TS staining. Neoadjuvant chemoradiation was performed in 33/35 patients. Downstaging was observed in 69% (9/13) of patients with negative pre-treatment TS levels versus 55% (11/20) in pre-treatment TS positive patients (p = 0.48). In 23 patients treated with 5FU, 9/12 (75%) were downstaged in the TS-negative cohort versus 6/11 (45%) in the TS-positive cohort (p = 0.21). In the 5FU treatment group, complete response was seen in 2 patients with negative TS staining. Conclusions: Low TS expression in EAC patients trended towards improved survival and tumor downstaging, particularly in patients treated with neoadjuvant 5-FU and platinum based therapy. Prospective data and greater patient numbers may be necessary to demonstrate statistical significance.
Responsiveness of histological disease activity indices in ulcerative colitis: a post hoc analysis using data from the TOUCHSTONE randomised controlled trial
Peyrin‐Biroulet, Laurent , Zou, Guangyong , Casteele, Niels Vande , Pai, Reetesh K. , Marchal-Bressenot, Aude, Stitt, Larry, Shackelton, Lisa M. , Khanna, Reena , D’Haens, Geert , Sandborn, William J. , Olson, Allan, Feagan, Brian G. , Pai, Rish K. , Vande Casteele, N , Peyrin-Biroulet, Laurent , Jairath, Vipul , Mosli, Mahmoud Hisham , Valasek, Mark A. , Zou, Guangyong

Gut | August 3, 2018 | Volume: 68 | Issue: 7 | Pages: 1162-1168

10.1136/gutjnl-2018-316702 Get It

Objective We evaluated the reliability and responsiveness of available but incompletely validated UC histological disease activity indices using standardised rules for centralised assessment. Design Disease activity was assessed in biopsies collected in a phase II placebo-controlled ozanimod trial by four blinded pathologists using the Geboes (GS) and modified Riley (MRS) scores, the Robarts Histopathology (RHI) and Nancy Histological (NHI) indices and a Visual Analogue Scale. Reliability was assessed with intraclass correlation coefficients (ICCs). Index responsiveness was evaluated by assessing longitudinal validity (Pearson correlations of changes in index scores and other disease measures), and effect size estimates (standardised effect size (SES)) using two criteria for change (treatment assignment and >2 point decrease in total Mayo Clinic score). Area under the receiver operating characteristic (AUROC) curve estimates evaluated the probability of the indices to discriminate between treatment and placebo. Results Inter-rater reliability of the histological indices was substantial to almost perfect (ICC>0.61), and responsiveness was moderate to large (SES estimates>0.5); 0.81 (0.52, 1.10), 0.87 (0.58, 1.17), 0.57 (0.30, 0.84) and 0.81 (0.52, 1.09) when treatment assignment was the criterion for change and 1.05 (0.80, 1.31), 1.13 (0.87, 1.39), 0.88 (0.64, 1.12) and 1.06 (0.80, 1.31) for the change in Mayo score criterion for the GS, MRS, RHI and NHI, respectively. The indices had similar drisciminative ability based on AUROC estimates (range 0.608–0.649). Conclusion All four existing histological indices were similarly reliable and responsive based on this dataset.
Editorial: validating reliability of the eosinophilic oesophagitis histological scoring system (EOE‐HSS)—an important first step. Authors’ reply
Pai, Rish K. , Bredenoord, Albert J. , Feagan, Brian G. , Jairath, Vipul , Jairath, Vipul , Jairath, Vipul , Feagan, B G , Jairath, V , Jairath, V , Jairath, Vipul

Alimentary Pharmacology & Therapeutics | May 31, 2018 | Volume: 47 | Issue: 12 | Pages: 1714-1715

10.1111/apt.14658 Get It

Linked contentThis article is linked to Warners et al and Conner and Kirsch papers. To view these articles https://doi.org/10.1111/apt.14559 and https://doi.org/10.1111/apt.14633.
Systematic review with meta‐analysis: endoscopic and histologic placebo rates in induction and maintenance trials of ulcerative colitis
Ma, Christopher , Guizzetti, Leonardo , Pai, Rish K. , Parker, Claire E. , Nguyen, Tran M , Khanna, Reena , Casteele, Niels Vande , D’Haens, Geert , Sandborn, William J. , Feagan, Brian G. , Ma, C , Guizzetti, L , Fedorak, R N , Pai, R K , Vande Casteele, N , D'Haens, G , Sandborn, W J , Feagan, B G , Jairath, V , Panaccione, Remo , Fedorak, Richard N. , Jairath, Vipul

Alimentary Pharmacology & Therapeutics | April 26, 2018 | Volume: 47 | Issue: 12 | Pages: 1578-1596

10.1111/apt.14672 Get It

Summary Background Regulatory requirements for claims of mucosal healing in ulcerative colitis ( UC ) will require demonstration of both endoscopic and histologic healing. Quantifying these rates is essential for future drug development. Aims To meta‐analyse endoscopic and histologic placebo response and remission rates in UC randomised controlled trials ( RCT s) and identify factors influencing these rates. Methods MEDLINE , EMBASE and the Cochrane Library were searched from inception to March 2017 for placebo‐controlled trials of pharmacological interventions for UC . Endoscopic and histologic placebo rates were pooled by random effects. Mixed effects univariable and multivariable meta‐regression was used to evaluate the influence of patient, intervention and trial‐related study‐level covariates on these rates. Results Fifty‐six induction (placebo n = 4171) and 8 maintenance trials (placebo n = 1011) were included. Pooled placebo endoscopic remission and response rates for induction trials were 23% [95 confidence interval ( CI ) 19‐28%] and 35% [95% CI 27‐42%] respectively, and 20% [95% CI 16‐24%] for maintenance of remission. The pooled histologic placebo remission rate was 14% [95% CI 8‐22%] for induction trials. High heterogeneity was observed for all outcomes ( I 2 56.2%‐88.3%). On multivariable meta‐regression, central endoscopy reading was associated with significantly lower endoscopic placebo remission rates (16% vs 25%; OR = 0.52, [95% CI 0.29‐0.92], P = 0.03). On univariable meta‐regression, higher histologic placebo remission was associated with concomitant corticosteroids ( OR = 1.17 [95% CI 1.08‐1.26], P < 0.0001, per 10% increase in corticosteroid use). Conclusions Placebo endoscopic and histologic rates range from 14% to 35% in UC RCT s but are highly heterogeneous. Outcome standardisation may reduce heterogeneity and is needed in this field.
Gastric pyloric gland adenoma: a multicentre clinicopathological study of 67 cases
Choi, Won‐Tak , Brown, Ian , Ushiku, Tetsuo , Yozu, Masato , Setia, Namrata , Srivastava, Amitabh , Johncilla, Melanie , Pai, Rish K. , Fukayama, Masashi , Misdraji, Joseph , Lauwers, Gregory Y. , Brown, Ian S , Gill, Ryan M. , Srivastava, Amitabh

Histopathology | December 26, 2017 | Volume: 72 | Issue: 6 | Pages: 1007-1014

10.1111/his.13460 Get It

AimsThere is limited information regarding the clinicopathological and immunohistochemical characteristics of gastric pyloric gland adenomas (PGAs).Methods and resultsSixty‐seven cases of gastric PGA from 57 patients were analysed. PGAs occurred with similar frequency in men and women (47.4 and 52.6%, respectively), with a mean age of 66 years. Most presented in the gastric body/fundus (67.2%). Fifteen cases (22.4%) developed against a background of autoimmune gastritis (AIG), whereas normal mucosa was seen in 35.8%. Only 16.4% (11 cases) developed in patients with a genetic predisposition, most commonly familial adenomatous polyposis. Low‐grade lesions had a mean size of 1.5 cm, while PGAs with high‐grade dysplasia (HGD) or adenocarcinoma had a mean size of 3.5 cm (P < 0.001) and more commonly showed tubulovillous architecture (50.0 versus 25.6% in low‐grade dysplasia; P = 0.040). Most PGAs (61.2%) co‐expressed mucin (MUC)5AC and MUC6 (mixed type), which was associated significantly with HGD or adenocarcinoma (P = 0.013). AIG was also associated with HGD (P = 0.027), but genetic predisposition did not correlate with the grade of dysplasia (P = 0.793). The recurrence rate of PGA was similar for high‐ (11.8%) and low‐grade lesions (7.4%) (P = 0.624).ConclusionsThe risk of HGD increases with the size of PGA, tubulovillous architecture and the presence of AIG as well as mixed immunophenotype. As the overall local recurrence rate is less than 10%, PGAs may be treated conservatively, but they should be excised completely if possible, particularly if they are large or show high‐grade features.
Histologic scoring indices for evaluation of disease activity in Crohn’s disease
Novak, Gregor , Parker, Claire E. , Pai, Rish K. , MacDonald, John K, Feagan, Brian G. , Sandborn, William J. , D’Haens, Geert , Khanna, Reena , Jairath, Vipul

Cochrane Database of Systematic Reviews | July 21, 2017 | Volume: 2017 | Issue: 7 | Pages: No page available

10.1002/14651858.cd012351.pub2 Get It

Randomised clinical trial: a phase 1, dose‐ranging study of the anti‐matrix metalloproteinase‐9 monoclonal antibody GS‐5745 versus placebo for ulcerative colitis
Sandborn, William J. , Bhandari, Bal Raj, Fogel, Ronald, Onken, Jane E., Yen, Eugene F. , Zhao, Xin , Jiang, Zhaoshi , Ge, Dongliang , Xin, Y., Ye, Z., French, Dorothy, Silverman, Jeffrey A., Kanwar, Bittoo, Subramanian, G. Mani , McHutchison, John G., Lee, S. D., Shackelton, Lisa M. , Pai, Rish K. , Levesque, Barrett G., Feagan, Brian G. , Xin, Y.

Alimentary Pharmacology & Therapeutics | May 25, 2016 | Volume: 44 | Issue: 2 | Pages: 157-169

10.1111/apt.13653 Get It

SummaryBackgroundMatrix metalloproteinase‐9 is a proteolytic enzyme whose expression is increased in ulcerative colitis.AimTo evaluate the safety and efficacy of GS‐5745, a fully humanised anti‐matrix metalloproteinase‐9 monoclonal antibody, in moderately‐to‐severely active ulcerative colitis.MethodsWe randomised 74 patients with ulcerative colitis to treatment with single or multiple ascending intravenous or subcutaneous doses of GS‐5745 or placebo. Multiple‐dose cohorts received either IV infusions (0.3, 1.0, 2.5 or 5.0 mg/kg GS‐5745 or placebo) every 2 weeks (three total IV infusions) or five weekly SC injections (150 mg GS‐5745 or placebo). The primary outcomes were the safety, tolerability and pharmacokinetics of escalating single and multiple doses of GS‐5745. Exploratory analyses in the multiple‐dose cohorts included clinical response (≥3 points or 30% decrease from baseline in Mayo Clinic score and ≥1 point decrease in the rectal bleeding subscore or a rectal bleeding subscore ≤1) and clinical remission (a complete Mayo Clinic score ≤2 with no subscore >1) at Day 36. Biological effects associated with a clinical response to GS‐5745 were explored using histological and molecular approaches.ResultsTwenty‐three of the 42 patients (55%) receiving multiple doses of GS‐5745 had adverse events, compared with 5/8 patients (63%) receiving placebo. GS‐5745 showed target‐mediated drug disposition, approximately dose‐proportional increases in maximum plasma concentration and more than dose‐proportional increases in the area under the plasma drug concentration‐time curve. Clinical response occurred in 18/42 patients (43%) receiving GS‐5745 compared with 1/8 patients (13%) receiving placebo. Clinical remission occurred in 6/42 patients (14%) receiving GS‐5745 and 0/8 (0%) receiving placebo. Patients with a clinical response to GS‐5745 had reductions in matrix metalloproteinase‐9 tissue levels (mean 48.9% decrease from baseline compared with a mean 18.5% increase in nonresponders, P = 0.008) significant improvements in histopathology scores (confirmed with three separate histological disease activity indices), as well as changes in colonic gene expression that were consistent with reduced inflammation.ConclusionThis phase 1 trial provides preliminary evidence for the safety and therapeutic potential of GS‐5745 in the treatment of ulcerative colitis.
Prevalence of Helicobacter pylori in Gastric Hyperplastic Polyps
Horváth, Béla, Pai, Rish K.

International Journal of Surgical Pathology | May 9, 2016 | Volume: 24 | Issue: 8 | Pages: 704-708

10.1177/1066896916648380 Get It

Hyperplastic polyps of the stomach are routinely encountered during upper endoscopy and often arise in the setting of abnormal surrounding mucosa, particularly Helicobacter pylori, autoimmune gastritis, and reactive gastropathy. Not infrequently gastroenterologists fail to biopsy the surrounding mucosa, thus determining the underlying etiology of the gastric hyperplastic polyp can be difficult. Recently, the Rodger C. Haggitt Gastrointestinal Pathology Society published guidelines on the use of special stains. The society guidelines indicate that H pylori are not usually present in hyperplastic polyps and special stains in this setting may have limited utility. We analyzed the histologic features of 32 gastric hyperplastic polyps in which the nonpolypoid mucosa demonstrated H pylori gastritis. A consecutive series of 50 hyperplastic polyps in which no surrounding mucosa was sampled was also analyzed. When H pylori are identified in biopsies of the nonpolypoid mucosa, it is also commonly present within the polyp tissue (22/32, 69%). The majority of H pylori organisms were identified on routine hematoxylin and eosin stain (16/22, 72%). In contrast, H pylori were only seen in 2/50 consecutive hyperplastic polyps in which the surrounding mucosa was not sampled. Compared with the hyperplastic polyps that lack the organisms, H pylori associated hyperplastic polyps more commonly had dense lymphoplasmacytic inflammation ( P = .0001) and neutrophils within gastric epithelium ( P = .036). Polyp location, number, size, and presence of intestinal metaplasia was not associated with H pylori. These results provide empirical data to guide evaluation of hyperplastic polyps for H pylori.