Global patterns of amyloid typing: results of a survey by the International Society of Amyloidosis (ISA).

Abstract

Background: Accurate tissue typing in amyloidosis is essential to provide appropriate therapy for individual patients.

Objective: To get a real-life overview of typing strategies worldwide.

Methods: The International Society of Amyloidosis (ISA) performed an online questionnaire survey among ISA members. We prepared questionnaire sheets for referral institutions (Category 1; C1), institutions performing amyloid typing for internal requests only (C2), and institutions outsourcing amyloid typing to referral institutions (C3), respectively.

Results: Seventy-six institutions participated in this survey, including C1 (n = 33), C2 (n = 20) and C3 (n = 23) institutions. Multiple typing methods were available across the responding institutions, including immunohistochemistry (85% of C1/C2 institutions), immunofluorescence microscopy (43%), genetic analysis (77%) and mass spectrometric analysis (42%). Commercial antibodies were used worldwide for immunohistochemistry. C1 institutions in Europe and Asia also used various in-house antibodies. Ninety-three percent of institutions performed genetic analysis of TTR gene, followed by APOA1 (43%), FGA, GSN, LYZ (33%) and APOA2 (31%). Hierarchical referral flows of mass spectrometric analysis, immunohistochemistry and genetic analysis were observed regionally and internationally. Globalization and centralization of referral flows were more prominent for mass spectrometric analysis.

Conclusion: These data provide an assessment of the current state, enabling improvement in capabilities of amyloid typing worldwide and enhancing regional/international networks.