Investigators - Clinical/Translational - afkarian

Maryam Afkarian, MD, PhD

Project 1: Identification of early urinary biomarkers of diabetic kidney disease

This project involves a multi-step approach to identify the proteins that are altered in early Diabetic nephropathy (DN). In the first step, a labeled quantitative mass spectrometric platform (iTRAQ: isobaric Tags for Relative and Absolute Quantitation) will be used to compare urine samples from patients with and without DN (cases and controls, respectively). This hypothesis-free and unbiased comparative analysis will generate a preliminary list of candidate biomarkers for early DN. In the second stage, this list will be supplemented with hypothesis-driven candidates, i.e. those with significant evidence of involvement in DN. Examples are proteins which (a) are part of pathways incriminated in DN, (b) have altered mRNA expression in DN or (c) have altered protein level in DN. This step serves to incorporate all currently available information into this biomarker discovery effort. In the third step, a target-specific and quantitative assay, e.g. ELISA or MRM/SID, is used to re-evaluate the expression of putative biomarkers from the first two steps in an independent cohort. This step will help weed out the false positives and identify a subset of markers whose differential expression in DN is confirmed. Finally, the expression of these confirmed markers will be characterized over the course of disease. This proposal is designed to generate a group of candidate biomarkers for early DN which has been validated within the original study population. A future step would be to test these candidates in a broader and more varied population. In long term, we hope that the validated biomarkers would serve as a novel diagnostic tool for early DN and also help shed light on the disease pathophysiology.

Current Funding

K23 DK089017 (Afkarian, PI)
NIH/NIDDK (9/1/10-9/1/15)
Identifying urinary biomarkers for early type 2 diabetic nephropathy
Applying quantitative proteomic technology for identification of urinary biomarkers for early type 2 diabetic nephropathy using urine samples from the longitudinal study of diabetes and its complications in Pima Indians. 

Past Funding

3-2008-86 (Afkarian, Fellow)
Juvenile Diabetes Research Foundation (JDRF) (6/1/08-6/1/10)
Identification of urinary biomarkers of type 1 diabetic nephropathy
Postdoctoral salary support for work towards use of quantitative proteomic technology to identify urinary biomarkers for early type 1 diabetic nephropathy using urine samples from the Diabetes Control and Complications Trial (DCCT).


PubMed provides a list of Dr. Afkarian's research publications