Keratin (AKA) antibody titer

Category: Rheumatology
Test Code: 009
Disease: Rheumatoid Arthritis
Methodology: Indirect Immunofluorescence
Substrate: Rodent Esophagus
Reference Range: Negative: <1:10
Units: Titer
Note: Positive samples at a 1:10 screening dilution are titered to an endpoint at an additional charge, if requested.
CPT Code: 86255
Schedule / Turnaround Time: Assay performed daily Monday-Friday. Report availability is within 48 hours from the time of specimen receipt.
Specimen Requirements:

Specimen need not be refrigerated or frozen. Collect 2-3 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into white tube provided with Immco Diagnostics’ collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection.

Sample Stability:

Sample is stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8˚C) up to five days and frozen (-20˚C or lower) up to one year.


Keratin antibodies have a high degree of specificity for rheumatoid arthritis and can be used adjunct to rheumatoid factor (RF) and cyclic citrullinated peptides (CCP) antibodies in the diagnosis of rheumatoid arthritis.