Methods for measuring carcinoembryonic antigen
Disclosed herein are methods of accurately measuring carcinoembryonic antigen in a biological sample and methods of identifying and treating a mucinous cyst in a subject.
1. A method of measuring carcinoembryonic antigen in a biological sample, the method comprising:
diluting the biological sample with a diluent at a ratio of biological sample to diluent of about 1:10 to about 1:50 to form a diluted biological sample;
measuring the amylase level of the diluted biological sample;
measuring carcinoembryonic antigen level in the diluted biological sample; and multiplying the carcinoembryonic antigen level by a correction factor to obtain a corrected carcinoembryonic antigen level when the amylase level in the diluted samples is above about 10,000 units.
2. The method of claim 1 , wherein the diluent is saline, Diluent Universal, or a combination thereof.
3. The method of claim 1 , wherein the biological sample is undiluted prior to the diluting step.
4. The method of claim 1 , wherein diluting the biological sample with a diluent comprises diluting the biological sample with a diluent in a ratio of about 1:10.
5. The method of claim 1 , wherein diluting the biological sample with a diluent comprises diluting the biological sample with a diluent in a ratio of about 1:40.
6. The method of claim 1 , wherein the correction factor is about 0.7.
7. The method of claim 1 , wherein the biological sample is not present in sufficient volume to accurately measure carcinoembryonic antigen level.
8. The method of claim 1 , wherein the biological sample has a high viscosity.
9. The method of claim 8 , wherein the high viscosity is due to the presence of mucin in the biological sample.
10. The method of claim 1 , wherein the carcinoembryonic antigen levels in the biological sample exceed the measurement capabilities of an instrument being used to measure carcinoembryonic antigen level.
11. The method of claim 1 , wherein the biological sample is selected from pancreatic fluid, pancreatic cyst fluid and combinations thereof.
12. The method of claim 1 , wherein a corrected carcinoembryonic antigen level above a predetermined carcinoembryonic antigen threshold is indicative of a pathological condition.
13. The method of claim 12 , wherein the carcinoembryonic antigen level threshold is about 192 ng/ml or about 400 ng/ml.
14. The method of claim 12 , wherein the pathological condition is a neoplastic condition or a non-neoplastic condition.
15. The method of claim 14 , wherein the neoplastic condition is selected from colorectal carcinoma, gastric carcinoma, cholangiocarcinoma, pancreatic carcinoma, intraductal papillary mucinous neoplasm (IPMN), lung carcinoma, breast carcinoma, medullary thyroid carcinoma, and combinations thereof.
16. The method of claim 14 , wherein the non-neoplastic condition is selected from ulcerative colitis, pancreatitis, pancreatic cysts, pancreatic masses, biliary strictures, cirrhosis, chronic obstructive pulmonary disease, Crohn's disease, intraductal papillary mucinous neoplasm (IPMN), and combinations thereof.
17. The method of claim 1 , wherein the carcinoembryonic antigen level is multiplied by a correction factor to obtain a corrected carcinoembryonic antigen level when the amylase level in the diluted sample is above about 20,000 units.