Leaders in Pharmaceutical Business Intelligence (LPBI) Group

Curated by: Dr. Venkat S. Karra, Ph.D.

In our recent article we mentioned about the amyloidosis, most importantly the most common form of amlyodosis – Primary Amyloidosis (AL).

Primary amyloidosis (AL) is an acquired plasma cell disorder in which a monoclonal immunoglobulin light chain is produced in the bone marrow and usually found in the blood or urine. AL amyloidosis occasionally occurs with multiple myeloma. The amyloid fibrils in this type of amyloidosis are made up of immunoglobulin light chain proteins (kappa or lambda).

Amyloidosis can only be diagnosed by a positive biopsy (i.e., an identification of the amyloid deposits in a piece of tissue). Initial biopsies are most commonly obtained from the abdominal fat.

If amyloid is suspected in other organs, however, a biopsy may be needed from these specific areas. If amyloid is present in a tissue biopsy, further tests can be done to determine the type of the amyloid.

The Amyloid Treatment & Research Program (ATRP) at Boston Medical Center (BMC) is an international referral center that treats amyloidosis with stem cell transplantation.

Last week researchers at Mayo Clinic have used urinary exosomes as a non-invasive diagnostic tool that will offer a snapshot of what is occurring in kidney tissue.

Urinary exosomes are rapidly becoming a powerful tool in the study of renal disease.

Already proteomics studies are looking into ways of using urinary exosome to diagnose genetic diseases and characterize disease biomarkers.

The urinary exosomes are excreted from every renal epithelial cells (from the glomerular podocytes to the urinary epithelial cells lining the urinary drainage system) provides us with an opportunity to study proteins once were either difficult or impossible to reach.

With this understanding the researchers undertook this study to evaluate the possible differences among urinary exosomes from patients with different plasma cells dyscrasias. This study suggests that urinary exosomes may be an excellent non-invasive tool for identifying patients with AL amyloidosis because high molecular weight light chain oligomers were found only in patients with AL.

The oligomeric light chain species captured in the urinary exosomes may represent the initial steps of amyloidogenesis. The potential of urinary exosomes in AL is tremendous and deserves further studies. When combined with mass spectrometry and other proteomics techniques, urinary exosomes represent tremendous potential to increase our understanding of amyloidogenesis.

Authors believe that this is the first report of the use of urinary exosome in the study of patients with plasma cell dyscrasias, specifically patients with AL amyloidosis.

References:

1. Amyloidosis: http://pharmaceuticalintelligence.com/2012/06/04/amyloidosis/

2. Alzheimers Disease: http://pharmaceuticalintelligence.com/category/alzheimers-disease-2/

3. Prospects for urinary proteomics: exosomes as a source of urinary biomarkers

4. Source article: Differences in Immunoglobulin Light Chain Species Found in Urinary Exosomes in Light Chain Amyloidosis (AL)

5.  Exosomal Fetuin-A identified by proteomics: a novel urinary biomarker for detecting acute kidney injury.

 6. Characterization of PKD protein-positive exosome-like vesicles.

7. Large-scale proteomics and phosphoproteomics of urinary exosomes.

8. Proteomic analysis of urinary exosomes from patients of early IgA nephropathy and thin basement membrane nephropathy.