[Retrospective analysis of a patient cohort with suspicion of systemic amyloidosis, finally not confirmed].

Systemic amyloidoses present with non-specific symptoms which lead to a wide spectrum of possible differential diagnoses. In this retrospective study we analyzed a patient cohort that was referred to the amyloidosis center Heidelberg under the suspicion of amyloidosis but ultimately did not receive the diagnosis of amyloidosis after diagnostic work-up. The usefulness of differential diagnosis (DDX) generators in the diagnostic process of amyloidosis is unclear.Included in this retrospective analysis were the data of patients who were referred to the amyloidosis center between 2014 and 2020 and who did not receive the diagnosis of amyloidosis.In order to test the usefulness of the DDX-Generator, 90 patients without amyloidosis were selected from this cohort and compared to another cohort of 30 random patients with confirmed amyloidosis.The diagnosis of amyloidosis was ruled out in 351/2829 (12,4%) patients. The most frequent diagnoses were polyneuropathies (n=129/351, 36,7%) and cardiomyopathies (n=76/351, 21,7%). Plasma cell dyscrasia associated diseases were only present in 17/351 (4,8%) of patients. The cause of the disease remained unknown in 160/186 (86,0%) patients with a mean follow-up time of 34,5 months.In the non-amyloidosis cohort, the DDX generator listed amyloidosis as a possible differential diagnosis in the top 10 differential diagnoses in 25/90 (27,8%) cases.In the amyloidosis-cohort, amyloidosis was significantly more often present in the top 10 differential diagnoses (n=28/30, 93,3%,).Point of contact for patients with unknown or rare diseases are the centers for rare diseases. DDX-Generators could aid physicians to consider amyloidosis as a possible differential diagnosis.