A Normalized Spot-Sample Estimation of α-1 Antitrypsin Clearance - The Search for a Simpler Test in Protein Losing Enteropathy

Sep 29, 2026

Upload by dawugda

Protein losing enteropathy (PLE) is typically diagnosed after excluding other causes and confirming with cumbersome testing. This study evaluated whether a spot-stool sample estimation of α-1 antitrypsin can diagnose PLE by controlling for serum α-1 antitrypsin concentration and stool dilution. Consecutive, consented patients referred for scintigraphy were assessed with serum α-1 antitrypsin, spot stool α-1 antitrypsin, and stool elastase. Results showed high sensitivity for ruling out PLE but limited specificity, and normalization ratios added no diagnostic value.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages6

Reading Time15 min

AccessFree to download

Introduction

Materials and Methods

Technetium-99m-Labeled Human Serum Albumin Scintigraphy

Results

Conclusion

Article published online: 2025-11-23 346 Original Article THIEME A Normalized Spot-Sample Estimation of α-1 Antitrypsin Clearance: The Search for a Simpler Test in Protein Losing Enteropathy Anjilivelil J. Joseph 1 Anoop John 1 Junita Rachel John2 Julie Hephzibah2 Ebby George Simon 1 Amit K. Dutta 1 Sudipta Dhar Chowdhury 1 Reuben Thomas Kurien 1 Dilip Abraham3 1 Department of Gastroenterology, Christian Medical College and Hospital, Vellore, Tamil Nadu, India 2 Department of Nuclear Medicine, Christian Medical College and Hospital, Vellore, Tamil Nadu, India 3 Department of Wellcome Trust Research Laboratory, Christian Medical College and Hospital, Vellore, Tamil Nadu, India World J Nuclear Med 2025;24:346–351. Address for correspondence Anjilivelil J. Joseph, MD, DM, Department of Gastroenterology, Christian Medical College and Hospital, Vellore, Tamil Nadu 632004, India (e-mail: [ajjoseph@cmcvellore.ac.in](ajjoseph@cmcvellore.ac.in)). Abstract Keywords ► protein losing enteropathy ► antitrypsin ► elastase ► scintigraphy ► hypoalbuminemia Introduction Protein losing enteropathy (PLE) is usually a diagnosis of exclusion, which requires cumbersome tests to conﬁrm. In the quest for a simpler diagnostic test, we hypothesized that a spot stool sample estimation of α-1 antitrypsin will be sufﬁcient to make a diagnosis of PLE, if we control for serum α-1 antitrypsin concentration and degree of stool dilution. Materials and Methods Consecutive patients with a clinical suspicion of PLE and who had been advised a scintigraphy study were recruited after getting informed consent. The study excluded patients less than 1 year of age, pregnant women, and those with a clinical suspicion of chronic pancreatitis. Serum α-1 antitrypsin, spot stool α-1 antitrypsin, and stool elastase was assessed in all the patients. The diagnostic value of the index test was estimated from the patients with positive scintigraphy scan compared with a negative scan, expressed as sensitivity and speciﬁcity and the area under the receiver operating characteristic curve (AUROC) . Result A total of33patients underwent scintigraphy with a clinical suspicion of PLE. Twenty patients (60%) showed tracer activity in the gut suggestive of PLE. Spot stool α-1 antitrypsin below 0.26mg/g had a sensitivity of 100% to rule out PLE; however, the speciﬁcity was only 46%. Spot stool α-1 antitrypsin/(serum α-1 antitrypsin 􀀁 elastase) ratio performed similar to spotstool α-1antitrypsinasa diagnostic test(AUROC:0.814[0.61–1.0]vs.0.796[0.54–1.0]). Conclusion Random stool antitrypsin is a sensitive test for diagnosing PLE; however, it lacks speciﬁcity. Spot stool α-1 antitrypsin/(serum α-1 antitrypsin 􀀁 stool elastase) does not provide any additional value in the diagnosis of this syndrome. Introduction Protein losing enteropathy (PLE) is a syndrome where thereis excessive loss of protein from the gastrointestinal (GI) article published online November 23, 2025 DOI [https://doi.org/](https://doi.org/)[ ](https://doi.org/)10.1055/s-0045-1813661 . ISSN 1450-1147. tract. It can be caused by various disorders and include erosive and nonerosive GI disease and those due to lymphatic obstruction.1 In a patient with hypoalbuminemia, PLE is usually a diagnosis of exclusion once proteinuria, decreased © 2025 . The Author(s) . This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited.([https://creativecommons.org/licenses/by/4.0/](https://creativecommons.org/licenses/by/4.0/)) Thieme Medical and Scientiﬁc Publishers Pvt. Ltd. , A-12, 2nd Floor, Sector 2, Noida-201301 UP, India Normalized Spot Stool Elastase in Protein Losing Enteropathy Joseph et al. 347 protein synthesis (i.e., liver cirrhosis), and malnutrition are ruled out. Conﬁrmation of PLE is cumbersome and is established

FAQs

Why is diagnosing protein losing enteropathy (PLE) considered difficult?

PLE is usually diagnosed as a diagnosis of exclusion, requiring cumbersome confirmatory tests. The study emphasizes that confirmation typically involves 24-hour α-1 antitrypsin clearance and/or radiotracer scintigraphy.

What was the main hypothesis of the study?

The researchers hypothesized that a spot stool sample estimation of α-1 antitrypsin could be sufficient to diagnose PLE if serum α-1 antitrypsin levels and stool dilution are controlled.

How did the spot stool α-1 antitrypsin test perform for ruling out PLE?

A spot stool α-1 antitrypsin below 0.26 mg/g showed sensitivity of 100% to rule out PLE, but specificity was only 46%.

Sep 29, 2026

Upload by dawugda