Open Access
CC BY 4.0 · World J Nucl Med 2025; 24(04): 346-351
DOI: 10.1055/s-0045-1813661
Original Article

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

Autor*innen

  • Anjilivelil J. Joseph

    1   Department of Gastroenterology, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
  • Anoop John

    1   Department of Gastroenterology, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
  • Junita Rachel John

    2   Department of Nuclear Medicine, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
  • Julie Hephzibah

    2   Department of Nuclear Medicine, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
  • Ebby George Simon

    1   Department of Gastroenterology, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
  • Amit K. Dutta

    1   Department of Gastroenterology, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
  • Sudipta Dhar Chowdhury

    1   Department of Gastroenterology, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
  • Reuben Thomas Kurien

    1   Department of Gastroenterology, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
  • Dilip Abraham

    3   Department of Wellcome Trust Research Laboratory, Christian Medical College and Hospital, Vellore, Tamil Nadu, India

Abstract

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 of 33 patients 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 0.26 mg/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 spot stool α-1 antitrypsin as a 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.

Authors' Contributions

A.J.—Concept and design, data collection, literature search, interpretation of data, manuscript writing.

A.J.J.—Conception and design, interpretation of data, guide, and review of manuscript.

J.R.J.—Technical support, data collection, review of manuscript, and critical revision

J.H.—Review of manuscript and critical revision.

E.S.—Technical support, review of manuscript, guide, and critical revision.

A.K.D.—Technical support, review of manuscript, guide, and critical revision.

S.D.C.—Technical support, review of manuscript, guide, and critical revision.

R.T.K.—Technical support, review of manuscript, guide, and critical revision.

D.A.—Technical support, review of manuscript, guide, and critical revision.




Publikationsverlauf

Artikel online veröffentlicht:
23. November 2025

© 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/)

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