Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Rheumatoid Factors occur in a wide variety of conditions including viral infections, chronic bacterial infections, myeloma, lymphoma and connective tissue disease. Healthy elderly people may also have a positive Rheumatoid Factor. In Rheumatoid Arthritis the Rheumatoid Factor may be positive or negative, high titres are seen in progressive and extra-articular disease.
Specimen container paediatric:
Serum (SST or plain tube)
Specimen container adult:
Serum (SST or plain tube)
Minimum volume paediatric:
1 ml
Minimum volume adult:
1 ml
Sample stability:
Unseparated sample:
Unknown
Separated sample:
24 hours at 15 to 25°C,
8 days at 2 to 8°C,
3 months at -20°C.
Freq analysis:
Daily
Add on test:
All urgent add ons via telephone on 0191 2821890, and must be confirmed via email to the appropriate email address [email protected]
Quality assurance:
UK NEQAS for General Autoimmune Serology
Interpretation:
In Rheumatoid Arthritis the Rheumatoid Factor may be positive or negative, high titres are seen in progressive and extra-articular disease.
Reference ranges:
Normal Range: 0 – 19 IU/ml
Other info:
Plasma- Lithium Heparin also acceptable. Serial monitoring of Rheumatoid Factor is not recommended, as there is not a useful correlation with disease activity.