- Email: [email protected]
Endoscopic markers in celiac disease: Are they useful?
Letters to the Editor
LETTERS
TO THE
EDITOR
Endoscopic markers in celiac disease: Are they useful? To the Editor: We read with interest the article by Bardella et al.1 on the reevaluation of duodenal endoscopic markers in the diagnosis of celiac disease (CD). In their article, these investigators concluded that a reappraisal of the value of endoscopic markers for CD in all patients undergoing upper endoscopy is needed, basing this assumption on the sensitivity (50%) and positive predictive value (60%) for these markers in a study of patients with dyspeptic symptoms. In our opinion, some conclusions of this report require further discussion. Undoubtedly, as stated by Bardella et al.,1 most data on the sensitivity and specificity of these markers were previously obtained in groups of patients in which there was some degree of suspicion of CD, and this fact could have influenced the statistical analysis. However, a previous study by Dickey et al.,2 in which biopsy specimens were taken in all patients, irrespective of endoscopic findings, reported a sensitivity of endoscopic markers of
VOLUME 54, NO. 2, 2001
87.5%, a specificity of 100%, positive predictive value of 100%, and negative predictive value of 99%. This study dealt with 150 consecutive patients undergoing firsttime endoscopy for upper GI symptoms or for iron deficiency anemia, with exclusion of patients specifically referred for the purpose of obtaining duodenal biopsy specimens. Apart from the high statistical values that differ significantly from those reported by Bardella et al.,1 this study represents the true situation that endoscopists encountered in daily clinical practice, in which unselected patients with upper GI symptoms undergo endoscopic evaluation. The choice of a subset of patients for endoscopic study, such as dyspeptic patients in the study of Bardella et al.,1 makes the statistical values not fully applicable to all patients undergoing upper endoscopy. A further question might arise regarding the number, experience, and above all, the interobserver agreement of the endoscopists involved (two centers participated) in the study of Bardella et al.1 These data were not presented, but nevertheless these factors could have strongly biased the results. Finally, Bardella et al.1 suggest that duodenal biopsy specimens be obtained in all patients with dyspepsia undergoing upper endoscopy. This point requires careful consideration and discussion in view of the low frequency of CD in this group (1.2%) and the question of cost-effectiveness of this approach, including cost-effectiveness by comparison with serologic screening tests.3 In our opinion, further studies are necessary, particularly studies of unselected populations undergoing endoscopy to clarify (1) the true incidence of CD in unselected patients, including differences among countries, and (2) the usefulness of endoscopic markers in selecting unsuspecting patients for obtaining duodenal biopsy specimens. Emilio Brocchi, MD Lucia Mangia, MD Gianfranco Epifanio, MD Bruno Misitano, MD Roberto Corinaldesi, MD Department of Internal Medicine and Gastroenterology University of Bologna Bologna, Italy REFERENCES 1. Bardella MT, Minoli G, Radaelli F, Quatrini M, Bianchi PA, Conte D. Reevaluation of duodenal endoscopic markers in the diagnosis of celiac disease. Gastrointest Endosc 2000;51: 714-6. 2. Dickey W, Hughes D. Prevalence of celiac disease and its endoscopic markers among patients having routine upper gastrointestinal endoscopy. Am J Gastroenterol 1999;94: 2182-6. 3. Volta U, Molinaro N, De Franceschi L, Fratangelo D, Bianchi FB. IgA antiendomysial antibodies on human umbilical cord tissue for celiac disease screening: save both money and monkeys. Dig Dis Sci 1995;40:1902-5. doi:10.1067/mge.2001.116177
GASTROINTESTINAL ENDOSCOPY
281
LETTERS
TO THE
EDITOR
Endoscopic markers in celiac disease: Are they useful? To the Editor: We read with interest the article by Bardella et al.1 on the reevaluation of duodenal endoscopic markers in the diagnosis of celiac disease (CD). In their article, these investigators concluded that a reappraisal of the value of endoscopic markers for CD in all patients undergoing upper endoscopy is needed, basing this assumption on the sensitivity (50%) and positive predictive value (60%) for these markers in a study of patients with dyspeptic symptoms. In our opinion, some conclusions of this report require further discussion. Undoubtedly, as stated by Bardella et al.,1 most data on the sensitivity and specificity of these markers were previously obtained in groups of patients in which there was some degree of suspicion of CD, and this fact could have influenced the statistical analysis. However, a previous study by Dickey et al.,2 in which biopsy specimens were taken in all patients, irrespective of endoscopic findings, reported a sensitivity of endoscopic markers of
VOLUME 54, NO. 2, 2001
87.5%, a specificity of 100%, positive predictive value of 100%, and negative predictive value of 99%. This study dealt with 150 consecutive patients undergoing firsttime endoscopy for upper GI symptoms or for iron deficiency anemia, with exclusion of patients specifically referred for the purpose of obtaining duodenal biopsy specimens. Apart from the high statistical values that differ significantly from those reported by Bardella et al.,1 this study represents the true situation that endoscopists encountered in daily clinical practice, in which unselected patients with upper GI symptoms undergo endoscopic evaluation. The choice of a subset of patients for endoscopic study, such as dyspeptic patients in the study of Bardella et al.,1 makes the statistical values not fully applicable to all patients undergoing upper endoscopy. A further question might arise regarding the number, experience, and above all, the interobserver agreement of the endoscopists involved (two centers participated) in the study of Bardella et al.1 These data were not presented, but nevertheless these factors could have strongly biased the results. Finally, Bardella et al.1 suggest that duodenal biopsy specimens be obtained in all patients with dyspepsia undergoing upper endoscopy. This point requires careful consideration and discussion in view of the low frequency of CD in this group (1.2%) and the question of cost-effectiveness of this approach, including cost-effectiveness by comparison with serologic screening tests.3 In our opinion, further studies are necessary, particularly studies of unselected populations undergoing endoscopy to clarify (1) the true incidence of CD in unselected patients, including differences among countries, and (2) the usefulness of endoscopic markers in selecting unsuspecting patients for obtaining duodenal biopsy specimens. Emilio Brocchi, MD Lucia Mangia, MD Gianfranco Epifanio, MD Bruno Misitano, MD Roberto Corinaldesi, MD Department of Internal Medicine and Gastroenterology University of Bologna Bologna, Italy REFERENCES 1. Bardella MT, Minoli G, Radaelli F, Quatrini M, Bianchi PA, Conte D. Reevaluation of duodenal endoscopic markers in the diagnosis of celiac disease. Gastrointest Endosc 2000;51: 714-6. 2. Dickey W, Hughes D. Prevalence of celiac disease and its endoscopic markers among patients having routine upper gastrointestinal endoscopy. Am J Gastroenterol 1999;94: 2182-6. 3. Volta U, Molinaro N, De Franceschi L, Fratangelo D, Bianchi FB. IgA antiendomysial antibodies on human umbilical cord tissue for celiac disease screening: save both money and monkeys. Dig Dis Sci 1995;40:1902-5. doi:10.1067/mge.2001.116177
GASTROINTESTINAL ENDOSCOPY
281