Insight into the Protein Composition of Immunoglobulin Light Chain Deposits of Eyelid, Orbital and Conjunctival Amyloidosis
- *Corresponding Author:
- Jan J Enghild
Department of Molecular Biology and Genetics
Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark
Tel: +45-8715 5449
E-mail: [email protected]
Received date: February 18, 2014; Accepted date: April 17, 2014; Published date: April 21, 2014
Citation: Nielsen NS, Poulsen ET, Klintworth GK, Enghild JJ (2014) Insight into the Protein Composition of Immunoglobulin Light Chain Deposits of Eyelid, Orbital and Conjunctival Amyloidosis. J Proteomics Bioinform S8:002. doi: 10.4172/jpb.S8-002
Copyright: © 2014 Nielsen NS, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Amyloidosis is a disease characterized by the formation of extracellular amyloid deposits. Immunoglobulin lightchain amyloidosis can appear as a local disorder presenting with mild symptoms or as a life threatening systemic disease. The systemic form of immunoglobulin light-chain amyloidosis is the most common type of amyloidosis in western countries although it is a rare disease. Identification of the proteins forming amyloid fibrils is essential for the diagnosis of the disease and knowledge about the overall protein composition of the deposits may lead to a larger understanding of the deposition events thereby facilitating a more detailed picture of the molecular pathology. In this pilot study, we investigated the protein composition of amyloid deposits isolated from human specimens of the eyelid, conjunctiva, and orbit. Deposits and internal control tissue (patient tissue without apparent deposits) were procured by laser capture microdissection. Proteins in the captured amyloid and control samples were quantified by liquid chromatography tandem mass spectrometry using the label-free exponential modified Protein Abundance Index (emPAI) method.
Immunoglobulin light chain kappa or lambda was found to be the most predominant protein in the amyloid deposits from the eyelid, conjunctiva, and orbit. Five proteins, apolipoprotein A-I, carboxypeptidase B2 (TAFI), complement component C9, fibulin-1 and plasminogen were found solely across all amyloid but not in the control tissue. In addition, the protein profiles identified apolipoprotein E and serum amyloid P component to be associated with the immunoglobulin light chain deposits across all three tissues analyzed. The method used in this study provided high sensitivity and specificity for the type of amyloid and may provide additional information on the pathology of the amyloid deposits in the ocular tissues studied.