Factors affecting the accuracy of amyloidosis identification and referral to a specialty centre

Abstract

Objective

Diagnostic algorithms for amyloidosis have evolved over the past decade, particularly with the incorporation of imaging-based techniques to detect amyloid cardiomyopathy. We sought to identify the key sources of amyloidosis misidentification in the community, which lead to false positive referrals to a tertiary centre.

Methods

We conducted a retrospective review of all referrals to the Amyloidosis Centre from 2010 to 2021 and identified cases lacking amyloid pathology upon final adjudication after extensive assessment at the centre. Factors for false positive referrals were examined.

Results

Among 2409 referrals of suspected amyloidosis, 147 (6%) demonstrated an absence of amyloid pathology. This percentage increased over time from 4% in 2010 to 13% in 2021. False positive referrals consisted of more people of colour. The most frequent source of inaccuracy was the erroneous staining of tissue specimens with Congo red, followed by suggestive findings on cardiac imaging. In recent years, misinterpretation of ^99mtechnetium- pyrophosphate scintigraphy emerged as a major source of false positive referrals.

Conclusion

Recognising these potential sources of diagnostic error in the workup of amyloidosis can improve patient care. Referral to a centre of excellence for amyloidosis helps confirm an accurate diagnosis and avoid mistreatment.

Keywords:

• Amyloidosis
• diagnosis
• referral
• false positive
• tertiary centre

Acknowledgements

The authors thank the multidisciplinary team for the care of patients and acknowledge the contributions of many staff members. The inception and maintenance of the database was the vision of the founding director, Dr. Martha Skinner.

Authors contributions

AS queried the database, collected and analysed data and wrote the manuscript; LM and TJ collected data and conceptualised the project; FR and VS performed research, edited and revised the final version.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The Amyloidosis Centre database and repository are supported by the Amyloid Research Fund of Boston University Chobanian & Avedisian School of Medicine.