Rheumatoid Factor

Interpretation

Method

Turbidimetric

Reference Ranges

(individual methods listed below)

Default Method

Units: IU/mL

Female		Male		Unknown
Age	Range	Age	Range	Age	Range
0-	0-14	0-	0-14	0-	0-14

Effective date: 09/14/2026

UWMC Chemistry Remisol [UAUTO]

Units: IU/mL

Female		Male		Unknown
Age	Range	Age	Range	Age	Range
0-	<15	0-	<15	0-	<15

Effective date: 08/31/2026

Guidelines

• Specialty Testing in Immunology

Ordering & Collection

Specimen Type

Blood

Collection

Preferred: 4 mL blood in GOLD SST or LIME GREEN PST tube
Also Acceptable: 4 mL blood in RED TOP, ORANGE TOP, GREEN TOP, or LAVENDER TOP tube

Handling Instructions

The laboratory must process the specimen within 2 hours of collection.

Quantity

requested: 1 mL serum/plasma
minimum: 0.5 mL serum/plasma

Processing

Separate plasma/serum within 2 hours of collection and refrigerate. Avoid repeated freezing and thawing Stability: Room Temperature: up to 1 day; Refrigerated: 8 days; Frozen at -20°C: 3 months

Performance

LIS Dept Code

Chemistry, Automated Panels (CHA)

Performing Location(s)

CL	Renton Core Lab 206-520-4600 Clinical Lab, Room 170 1601 Lind Ave SW Renton, WA 98057
UW-MT	Chemistry, Automated 206-520-4600 Clinical Lab, Room NW220, University of Washington Medical Center, 1959 NE Pacific street, Seattle, WA 98195

Frequency

Daily

Available STAT?

No

Billing & Coding

CPT codes

86431

LOINC

11572-5

Interfaced Order Code

UOW2568

Interfaced Result Code

UOW2568