Differentiation of Pancreatic Cyst Types by Analysis of Rheological Behavior of Pancreatic Cyst Fluid

Khamaysi, Iyad; Ammar, Aiman Abu; Vasilyev, Gleb; Arinstein, Arkadii; Chowers, Yehuda; Zussman, Eyal

doi:10.1038/srep45589

Cited by 10 publications

(5 citation statements)

References 23 publications

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“…This mixture consisted of an artificial mucus matrix product to which pancreatic enzyme extracts were added. The viscosity of this matrix was adjusted to 1.5 cP, based on previous rheology studies of pancreatic cyst fluid [ 37 ]. Recombinant pepsinogen C was diluted with this matrix at varied concentrations and used for gastricsin activity assays.…”

Section: Resultsmentioning

confidence: 99%

Translation of a Protease Turnover Assay for Clinical Discrimination of Mucinous Pancreatic Cysts

Suresh

Byers²,

Rajesh³

et al. 2022

Diagnostics

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The classification of pancreatic cyst fluids can provide a basis for the early detection of pancreatic cancer while eliminating unnecessary procedures. A candidate biomarker, gastricsin (pepsin C), was found to be present in potentially malignant mucinous pancreatic cyst fluids. A gastricsin activity assay using a magnetic bead-based platform has been developed using immobilized peptide substrates selective for gastricsin bearing a dimeric rhodamine dye. The unique dye structure allows quantitation of enzyme-cleaved product by both fluorescence and surface enhanced Raman spectroscopy (SERS). The performance of this assay was compared with ELISA assays of pepsinogen C and the standard of care, carcinoembryonic antigen (CEA), in the same clinical sample cohort. A retrospective cohort of mucinous (n = 40) and non-mucinous (n = 29) classes of pancreatic cyst fluid samples were analyzed using the new protease activity assay. For both assay detection modes, successful differentiation of mucinous and non-mucinous cyst fluid was achieved using 1 µL clinical samples. The activity-based assays in combination with CEA exhibit optimal sensitivity and specificity of 87% and 93%, respectively. The use of this gastricsin activity assay requires a minimal volume of clinical specimen, offers a rapid assay time, and shows improvements in the differentiation of mucinous and non-mucinous cysts using an accurate standardized readout of product formation, all without interfering with the clinical standard of care.

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Section: Resultsmentioning

confidence: 99%

Translation of a Protease Turnover Assay for Clinical Discrimination of Mucinous Pancreatic Cysts

Suresh

Byers²,

Rajesh³

et al. 2022

Diagnostics

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“…[ 14 ] However, the diagnostic accuracy, sensitivity, and specificity of the CEA level in cyst fluid vary according to the CEA cutoff. [ 15 16 ] Brugge et al . showed that with cyst fluid CEA cutoff level of 192 ng/ml has sensitivity of 75%, specificity of 83.6%, and diagnostic accuracy of 79% in differentiating mucinous from non-MPCs.…”

Section: Discussionmentioning

confidence: 99%

An international study of interobserver variability of “string sign” of pancreatic cysts among experienced endosonographers

et al. 2021

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Background and Objectives: No single optimal test reliably determines the pancreatic cyst subtype. Following EUS-FNA, the “string sign” test can differentiate mucinous from nonmucinous cysts. However, the interobserver variability of string sign results has not been studied. Methods: An experienced endosonographer performed EUS-FNA of pancreatic cysts on different patients and was recorded on video performing the string sign test for each. The videos were shared internationally with 14 experienced endosonographers, with a survey for each video: “Is the string sign positive?” and “If the string sign is positive, what is the length of the formed string?” Also asked “What is the cutoff length for string sign to be considered positive?” Interobserver variability was assessed using the kappa statistic (κ). Results: A total of 112 observations were collected from 14 endosonographers. Regarding string sign test positivity, κ was 0.6 among 14 observers indicating good interrater agreement ( P < 0.001) while κ was 0.38 when observers were compared to the index endosonographer demonstrating marginal agreement ( P < 0.001). Among observations of the length of the string in positive samples, 89.8% showed >5 mm of variability ( P < 0.001), indicating marked variability. There was poor agreement on the cutoff length for a string to be considered positive. Conclusion: String sign of pancreatic cysts has a good interobserver agreement regarding its positivity that can help in differentiating mucinous from nonmucinous pancreatic cysts. However, the agreement is poor on the measured length of the string and the cutoff length of the formed string to be considered a positive string sign.

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“…In our study,[ 2 ] we found that the cutoff value of pancreatic cyst fluid viscosity, ηc, can serve as an independent marker to distinguish between mucinous and non-mucinous cysts. It was found that ηc >1.3 cP characterizes mucinous cysts, whereas ηc >1.3 cP is typical for non-mucinous cysts.…”

mentioning

confidence: 86%

String sign

Khamaysi

Taha

Weishahi

et al. 2022

Endoscopic Ultrasound

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Differentiation of Pancreatic Cyst Types by Analysis of Rheological Behavior of Pancreatic Cyst Fluid

Cited by 10 publications

References 23 publications

Translation of a Protease Turnover Assay for Clinical Discrimination of Mucinous Pancreatic Cysts

Translation of a Protease Turnover Assay for Clinical Discrimination of Mucinous Pancreatic Cysts

An international study of interobserver variability of “string sign” of pancreatic cysts among experienced endosonographers

String sign

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