Abstract
BackgroundCorrect identification of the amyloidosis-causing protein is crucial for clinical management. Recently the Mayo Clinic reported laser-capture microdissection (LCM) with liquid chromatography-coupled tandem mass spectrometry (MS/MS) as a new diagnostic tool for amyloid diagnosis. Here, we report an independent implementation of this proteomic diagnostics method at the Princess Alexandra Hospital Amyloidosis Centre in Brisbane, Australia.ResultsFrom 2010 to 2014, 138 biopsies received from 35 different organ sites were analysed by LCM-MS/MS using Congo Red staining to visualise amyloid deposits. There was insufficient tissue in the block for LCM for 7 cases. An amyloid forming protein was ultimately identified in 121 out of 131 attempted cases (94 %). Of the 121 successful cases, the Mayo Clinic amyloid proteomic signature (at least two of Serum Amyloid P, ApoE and ApoA4) was detected in 92 (76 %). Low levels of additional amyloid forming proteins were frequently identified with the main amyloid forming protein, which may reflect co-deposition of fibrils. Furthermore, vitronectin and clusterin were frequently identified in our samples. Adding vitronectin to the amyloid signature increases the number of positive cases, suggesting a potential 4th protein for the signature. In terms of clinical impact, amyloid typing by immunohistochemistry was attempted in 88 cases, reported as diagnostic in 39, however, 5 were subsequently revealed by proteomic analysis to be incorrect. Overall, the referring clinician’s diagnosis of amyloid subtype was altered by proteomic analysis in 24 % of cases. While LCM-MS/MS was highly robust in protein identification, clinical information was still required for subtyping, particularly for systemic versus localized amyloidosis.ConclusionsThis study reports the independent implementation and evaluation of a proteomics-based diagnostic for amyloidosis subtyping. Our results support LCM-MS/MS as a powerful new diagnostic technique for amyloidosis, but also identified some challenges and further development opportunities.Electronic supplementary materialThe online version of this article (doi:10.1186/s12014-016-9133-x) contains supplementary material, which is available to authorized users.
Highlights
Correct identification of the amyloidosis-causing protein is crucial for clinical management
In clinical diagnostic laboratories the diagnosis of amyloidosis is made by histological examination of tissue biopsy samples with the presence of amyloidosis demonstrated by the Congo red immunohistochemical stain which results in a pale ‘salmon-pink’ staining that shows typical birefringence and dichroism effects when examined under polarised light microscopy [5]
laser-capture microdissection (LCM)‐mass spectrometry (MS)/MS identification of amyloid forming proteins LCM-MS/MS was attempted on 131 clinical biopsy samples referred to the Princess Alexandra Hospital Amyloidosis Centre between April 2010 and December 2014 (Fig. 1)
Summary
Correct identification of the amyloidosis-causing protein is crucial for clinical management. The Mayo Clinic reported laser-capture microdissection (LCM) with liquid chromatography-coupled tandem mass spectrometry (MS/MS) as a new diagnostic tool for amyloid diagnosis. Amyloidosis is a rare but devastating condition caused by deposition of misfolded proteins as aggregates in the Mollee et al Clin Proteom (2016) 13:30 to kill the clonal bone marrow plasma cells that produce the pathologic immunoglobulin light chain. Such therapies are inappropriate and harmful for other types of amyloidosis. In this study we report the implementation and evaluation of this novel diagnostic technique at a tertiary referral hospital in Brisbane Australia over 5 years
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
