Diagnosis of Minimal Amyloid Deposits Using the Congo Red Fluorescence Method: A Review

Abstract

The diagnosis of amyloidosis on tissue sections containing minute amounts of amyloid poses the severe problem of missing the correct diagnosis due to the low sensitivity of the classical Congo red procedure. Therefore, increasing the sensitivity using amyloid antibodies did advance the diagnosis by more than 2 years in a retrospective study. Even more sensitive is the Congo red fluorescence, by which hardly any misses of amyloid occur. However, diagnosing amyloid is not trivial. For arriving at a flawless diagnosis, the awareness of the many pitfalls is mandatory, in particular that of the sampling errors. The goal for the patient is to get the diagnosis of amyloid at the earliest stages concomitant with the clinician’s first suspicion in order to get an early typing of amyloid and a suitable respective therapy before organ damage can occur with the chance of even reverting the course of the otherwise fatal disease.