The term amyloid encompasses a large variety of misfolded proteins with varying amino acids unified by the antiparallel beta-pleated sheet configuration and characteristic Congo red staining. The etiology of these proteins is equally varied, ranging from neoplastic plasma cell disorder, hereditary causes to inflammatory disorders. The protean clinical manifestation makes a high index of clinical suspicion the first crucial step in the diagnosis. A battery of investigations needs to be carried out for a complete diagnosis of amyloidosis and its underlying etiology. Biopsy with Congo red staining constitutes the most important modality for confirmation of amyloid. For further testing, varying modalities with increasing complexity, such as immunohistochemistry, electron microscopy, and mass spectrometry, need to be employed. We discuss, in the course of the current chapter, this fascinating protein from a clinical diagnosis perspective. The requisite investigations are also discussed in detail.
Part of the book: Amyloidosis