Category
SEROLOGY/ IMMUNOLOGY
Sub Category
AUTOIMMUNE.
Synonyms/Aliases
RHEUMATOID ARTHRITIS FACTOR, RA LATEX, RF TITER.
Abbreviations
RF.
Type
INDIVIDUAL TEST.
2-3 HRS
2-3 HOURS
Method
LATEX AGGLUTINATION.
Temp
AMBIENT (48 HOURS), REFRIGERATED (7-14 DAYS), FROZEN (>30 DAYS).
Setup
ALL WORKING DAYS.
Components Parameters
N/A.
PRE-ANALYTIC CONSIDERATIONS
Test Ordering Instructions
FILL OUT TEST REQUEST FORM FULLY & LEGIBLY.
Patient preparation
N/A.
Sample type
SERUM.
Container/ preservative
SERUM SEPARATOR TUBE (SST/ GEL) OR PLAIN (RED TOP) VACUTAINER.
Sample volume
2 ML
Rejection criteria
LABELING ISSUE (UNLABELED/ MISLABELED); MISSING REQUEST FORM; MISMATCH BETWEEN REQUEST FORM & SAMPLE DETAILS; MISSING AGE/ GENDER; WRONG SAMPLE TYPE; INSUFFICIENT SAMPLE; HEMOLYZED, LIPEMIC SAMPLES.
Other Instructions
CENTRIFUGE SST (SERUM GEL TUBES) WITHIN 1-2 HOURS OF COLLECTION. CENTRIFUGE RED TOP VACUTAINERS AND ALIQUOT SERUM WITHIN 1-2 HOURS OF COLLECTION. THE SEPARATION VIAL MUST BE LABELED WITH AT LEAST 2 PATIENT IDENTIFIERS AND THE SAMPLE TYPE.
Reference intervals
NEGATIVE; TITRES ARE PROVIDED FOR POSITIVE CASES.
Clinical Utility
EVALUATE RHEUMATOID ARTHRITIS (RA) AS ONE COMPONENT OF A MULTI-CRITERIA DIAGNOSTIC PROCESS THAT CO-OPTS CLINICAL & OTHER LAB CRITERIA (REFER TO CURRENT ACR/ EULAR CRITERIA FOR DIAGNOSIS OF RHEUMATOID ARTHRITIS). IT IS LESS SPECIFIC FOR RA THAN ANTI-CCP.
Test Limitations/ Confounders
FALSE POSITIVES MAY OCCUR IN CHRONIC INFLAMMATORY STATES, OTHER AUTOIMMUNE DISEASES, IN SOME NORMAL INDIVIDUALS ETC.