The Amyloidosis Intersection: Dual Amyloid Types in a Single Host.

Background: Advances in fibril typing by mass spectrometry have improved the accuracy of amyloidosis diagnosis. Dual amyloidogenic proteins have been reported in deposits in sole and multiple different organs.

Methods: Five patients with dual amyloidoses were diagnosed between 1995 and 2022 by Congo red staining and fibril typing using the best available methods at the time of evaluation. Sequencing of TTR and GSN genes was performed. Literature search identified 46 additional cases.

Results: Three patients exhibited Waldenström macroglobulinemia-associated AL (n = 3) amyloidoses in conjunction with ATTRwt or AGel amyloidosis; two patients featured AL/ATTRwt and AA/ATTRwt amyloidoses. One patient demonstrated dual amyloidoses within one anatomical site; three patients featured two amyloidosis types at different anatomical sites; and one patient had dual amyloid deposits in a single anatomical site along with different sites. The time interval between diagnoses was 0-288 months, with the heart and kidneys being the most affected organs.

Conclusions: Our findings underscore the complexity of clinical presentation in amyloidosis, as multiple amyloid types can co-exist in a single individual and affect various anatomical sites. Accurate assessment of the clinical phenotype and thorough amyloid fibril typing from the target organs are essential for precise diagnosis and tailored treatment.

Trial Registration: ClinicalTrials.gov Identifier: NCT00898235.