METHODS FOR DETECTING PRE-DIABETES AND DIABETES USING DIFFERENTIAL PROTEIN GLYCOSYLATION

• US 20120208217A1
• Filed: 04/26/2012
• Published: 08/16/2012
• Est. Priority Date: 05/11/2009
• Status: Active Grant

• Current Assignee: DiabetOmics, Inc.
• Original Assignee: Diabetomics, LLC
• Inventors: Nagalla, Srinivasa R., Roberts, Charles T.
• Granted Patent: US 8,497,076 B2
• Time in Patent Office: Days
• US Class Current: 435/7.94
• CPC Class Codes: G01N 2333/42 Lectins, e.g. concanavalin, phytohaemagglutinin
• CPC Class Codes: G01N 2400/00 Assays, e.g. immunoassays or enzyme assays, involving carbohydrates
• CPC Class Codes: G01N 2440/38 addition of carbohydrates, e.g. glycosylation, glycation
• CPC Class Codes: G01N 2500/02 Screening involving studying the effect of compounds C on the interaction between interacting molecules A and B (e.g. A = enzyme and B = substrate for A, or A = receptor and B = ligand for the receptor)
• CPC Class Codes: G01N 2800/042 Disorders of carbohydrate metabolism, e.g. diabetes, glucose metabolism
• CPC Class Codes: G01N 2800/50 Determining the risk of developing a disease
• CPC Class Codes: G01N 2800/52 Predicting or monitoring the response to treatment, e.g. for selection of therapy based on assay results in personalised medicine; Prognosis
• CPC Class Codes: G01N 33/6893 related to diseases not provided for elsewhere

Abstract

Methods for identifying individuals who are not yet diabetic (pre-diabetic), but who are at significant risk of developing diabetes, such as type 2 diabetes, are disclosed herein. Methods are also provided for the identification of diabetic subjects. Also disclosed are methods for identifying individuals with diabetic complications. The methods include the identification of an overall glycosylation profile of proteins in a biological fluid, such as saliva, urine, or serum. In some examples, the methods include determining the amount of one or more protein in a biological fluid or determining the glycosylation pattern of one or more proteins in a biological fluid.

Claims

1. A method for identifying a subject with a metabolic condition, comprising:

determining a first glycosylation profile of a first sample from the subject, wherein the first glycosylation profile comprises one or more parameters relating to glycosylation; and

comparing the first glycosylation profile to a second glycosylation profile of a second sample from a control subject, wherein the second glycosylation profile comprises one or more parameters relating to glycosylation, wherein the control subject does not have a metabolic condition, and wherein an increase in one or more parameters relating to glycosylation in the first sample relative to the one or more parameters relating to glycosylation in the second sample indicates that the subject has a metabolic condition.

2. The method of claim 1, wherein the metabolic condition is pre-diabetes or diabetes.

3. The method of claim 1, wherein both of the first and second samples comprise urine, saliva, or serum.

4. The method of claim 1, wherein determining the glycosylation profile of the first and second samples comprises measuring binding of one or more lectins to the first and second samples, and wherein the increase in one or more parameters relating to glycosylation comprises an increase in binding of one or more lectins to the first sample relative to the second sample.

5. The method of claim 4, wherein the one or more lectins are selected from the group consisting of Aleuria aurantia lectin, Concanavalin A, Datura stramonium lectin, Erythrina cristagalli lectin, Lycopersicon esculentum lectin, Maackia amurensis lectin I, Phaseolus vulgaris agglutinin, and Sambucus nigra lectin.

6. The method of claim 4, wherein the one or more lectins comprise Aleuria aurantia lectin, Datura stramonium lectin, or Phaseolus vulgaris agglutinin, and wherein an increase in Aleuria aurantia lectin, Datura stramonium lectin, or Phaseolus vulgaris agglutinin binding to the first sample relative to the second sample indicates the subject has pre-diabetes.

7. The method of claim 4, wherein the one or more lectins comprise Concanavalin A or Sambucus nigra lectin, and wherein an increase in Concanavalin A or Sambucus nigra lectin binding to the first sample relative to the second sample indicates the subject has pre-diabetes.

8. The method of claim 1, further comprising determining a quantity of at least one protein in the sample from the subject, wherein a difference in the quantity of the at least one protein in the sample from the subject as compared to the sample from the normal control subject indicates that the subject has pre-diabetes or diabetes.

9. The method of claim 8, wherein determining the quantity of at least one protein comprises determining the quantity of alpha-1 acid glycoprotein (A1AG) or alpha-1 antitrypsin (A1AT) protein in the sample.

10. The method of claim 9, wherein an increase in the quantity of A1AG, A1AT, or a combination thereof, as compared to the control sample indicates that the subject has pre-diabetes or diabetes.

11. The method of claim 9, wherein determining the quantity of at least one protein comprises performing an immunoassay.

12. The method of claim 1, further comprising:

determining a glycosylation state of at least one protein in the first sample; and

comparing the glycosylation state of the at least one protein in the first sample to the glycosylation state of the at least one protein in the second sample, wherein a difference in the glycosylation state of the at least one protein in the first sample as compared to the glycosylation state of the at least one protein in the second sample indicates that the subject has pre-diabetes or diabetes.

13. The method of claim 12, wherein the at least one protein alpha-1 acid glycoprotein (A1AG) and/or alpha-1 antitrypsin (A1AT).

14. The method of claim 13, wherein determining the glycosylation state of the at least one protein comprises detecting and/or measuring lectin binding to the at least one protein.

15. The method of claim 14, wherein the lectin comprises one or more lectins that bind alpha-1 acid glycoprotein.

16. The method of claim 15, wherein the lectin comprises Concanavalin A, Aleuria aurantia lectin, and/or Sambucus nigra lectin.

17. The method of claim 16, wherein increased lectin binding by Concanavalin A and/or Sambucus nigra lectin to the at least one protein the first sample as compared to the at least one protein in the second sample indicates the subject has pre-diabetes.

18. The method of claim 12, further comprising determining a quantity of the at least one protein in the first and second samples.

19. The method of claim 18, wherein determining the quantity of the at least one protein comprises determining the quantity of alpha-1 acid glycoprotein (A1AG) and/or alpha-1 antitrypsin (A1AT) protein in the first and second samples, and wherein an increase in the quantity of A1AG and/or A1AT, in the first sample as compared to the second sample indicates that the subject has pre-diabetes or diabetes.

20. The method of claim 18, wherein determining the quantity of the at least one protein comprises performing an immunoassay.

21. The method of claim 1, wherein determining the glycosylation profile of the first sample comprises contacting a the first sample with a lateral flow device comprising one or more lectins.

22. The method of claim 21, wherein the one or more lectins is selected from the group consisting of Aleuria aurantia lectin, Concanavalin A, Datura stramonium lectin, Erythrina cristagalli lectin, Lycopersicon esculentum lectin, Maackia amurensis lectin I, Phaseolus vulgaris agglutinin, and Sambucus nigra lectin.

23. The method of claim 1, wherein the metabolic condition is a diabetic complication.

24. The method of claim 23, wherein the diabetic complication is a microvascular complication or a macrovascular complication.

25. The method of claim 24, wherein the diabetic complication is a microvascular complication comprising one or more of diabetic nephropathy, diabetic retinopathy, and diabetic neuropathy.