Biomarkers Differentiate Types of Uveitis

Stanford researchers in Dr. Mahajan's laboratory have discovered biomarkers to differentiate between infectious (endophthalmitis) and non-infectious uveitis; and, to accurately categorize the types of infectious uveitis. With these biomarkers, a more efficient and reliable approach compared to conventional methods (mainly clinical findings and gram stains/cultures) can be used to treat uveitis caused by bacteria, viruses, fungi, helminths, or parasites. Instead of waiting days or weeks for laboratory results to determine microbial content, use of biomarkers to identify the etiology of uveitis is faster, more accurate, and more reliable. Particularly in ocular inflammatory cases, waiting for the correct diagnosis and treatment (50% of cases are idiopathic) can cause visual impairment, and ultimately blindness due to the recurrent and chronic nature of the disease process. Proteomic analysis was used to characterize the molecular profiles of the inflamed vitreous by taking biopsies from patients with various vitreoretinal diseases. This technique allowed researchers to identify characteristic protein signatures relating to infectious endophthalmitis and non-infectious uveitis in a mass spectrometry-based screen.

Figure

Figure Description: Proteomic profiles differ between classes of infectious endophthalmitis: (A) Hierarchal clustering of proteins differentially expressed in our infectious endophthalmitis samples (all classes) compared to normal controls (ERM). Results are represented as a heatmap and display protein expression levels on a logarithmic scale. Orange = high expression. Dark green/black = low or no expression. A total of 89 proteins were upregulated and a total of 88 proteins were downregulated (p 0.05). (B) Protein signatures were categorized by infection class (bacterial, viral, and fungal) and further analyzed by comparative Venn diagram analysis.

Stage of Development

Protein biomarkers are now being validated in a custom multiplex ELISA array