Systemic Amyloidosis Diagnosed in Formalin-Fixed Tissue

Proteins are solubilized for mass spectrometric analysis of formalin-fixed paraffin-embedded (FFPE) tissue, the standard form of preserved patient tissue used in clinical pathology testing.

Expression Pathology, Inc. (EPI; Rockville, MD, USA) announced that the Mayo Clinic (Rochester, MN, USA) has licensed nonexclusive rights to Expression Pathology's Liquid Tissue methodology, which solubilizes proteins, for use in diagnosis of systemic amyloidosis in formalin-fixed tissue. The new test is being offered to patients worldwide through Mayo Medical Laboratories (Rochester, MN, USA), the Mayo Clinic's reference laboratory.

The Liquid Tissue-based method aids in treatment decisions as it exhibits greater sensitivity and specificity than the traditional immunohistochemistry (IHC)-based classification. In a case study of 56 FFPE cardiac biopsies involving amyloidosis, IHC was diagnostic in 19/52 cases and equivocal in 33/52 cases (4 cases no IHC). The mass spectrometry-based Liquid Tissue method identified the amyloidosis type in 53 of 56 cases studied.

Amyloidosis can be a localized or systemic disease, characterized by organ function impairment, sometimes as severe as cardiac and/or renal failure. Subtyping of cases is critical as management of the disease differs radically, from drug therapies to major organ transplants.

"Detailed mass spectrometry analysis of proteins related to specific disease conditions in FFPE tissue is opening huge opportunities in personalized medicine to relate those measurements to patient treatment decisions,” said Casey Eitner, president and CEO of Expression Pathology. "We are delighted that Mayo Clinic has applied our Liquid Tissue methodology to solve a difficult medical problem.”

The Mayo Clinic offers diagnostic tests to more than 5,000 healthcare institutions around the world through Mayo Medical Laboratories.

Expression Pathology Inc. developed techniques for discovery and quantitative analysis of protein biomarkers in FFPE tissue. The company's Director laser microdissection slides enable precise, rapid, automated collection of specific cellular features from tumor tissue.

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Expression Pathology
Mayo Medical Laboratories