Methods and reagents for diagnosis and treatment of diabetes

1. A method of determining islet cell-specific activity in an individual, the method comprising,

detecting the level of a polypeptide comprising SEQ ID NO:9 in a sample wherein the said sample comprises human blood from the individual, and

determining islet cell-specific activity in the individual by comparing the level of the polypeptide in the sample to a baseline value or range associated with a known islet cell activity wherein said islet cell activity is associated with the ability of the islet cell to produce said polypeptide.

2. The method of claim 1 , wherein the polypeptide comprises an amino acid sequence selected from the group consisting of SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, and SEQ ID NO:14.

3. The method of claim 1 , wherein the polypeptide comprises SEQ ID NO:2.

4. The method of claim 1 , wherein the polypeptide is detected by an antibody.

5. The method of claim 1 , wherein the baseline or range is representative of the level of the polypeptide in a non-diabetic individual.

6. The method of claim 1 , wherein the level of the polypeptide in the individual is altered compared to a level of the polypeptide in a non-diabetic individual.

7. The method of claim 6 , wherein the level of the polypeptide in the individual is lower than a level of the polypeptide in a non-diabetic individual.

8. The method of claim 6 , wherein the altered level of the polypeptide in the individual is higher than a level of the polypeptide in a non-diabetic individual.

9. The method of claim 6 , wherein the level of the polypeptide in the individual is less than 50% of the level from the non-diabetic individual.

10. The method of claim 6 , wherein the level of the polypeptide in the individual is at least 150% of the level from the non-diabetic individual.