Author : Saad Al-Attabi, Alaa
Sensitivity and specificity of Rheumatoid factor and anti-cyclic citrullinated protein antibody positivity in patients with rheumatoid arthritis in karbala city
karbala journal of pharmaceutical sciences,
Volume 7, Issue 11, Pages 110-115
Rheumatoid arthritis (RA) is systemic autoimmune disease of unknown etiology
which characterize by joint and systemic involvement can lead to sever disability. The
rheumatoid factor is one of the main serological test for diagnosis but is of low
specificity since it is found in healthy people and other diseases . Anti- citrullinated
protein antibody (anti-CCP) which is more specific and less sensitive is considered as
another serological marker for diagnosis of RA. So that this was done to measure the
sensitivity and specificity of RF and anti-CCP in patients with rheumatoid arthritis.
The study included 260 patient with RA and 130 healthy subjects their sera were
used for measuring RF by latex agglutination technique and measuring anti-CCP by
ELISA technique. This study was found the sensitivity ,specificity , positive
predictive value and negative predictive value for RF were (86.9%) , (96%)
,(97%)and (78%) respectively , while those for AntiCCP were 73% ,100% ,
(100%)and (65%) respectively. The p value for RF anti-CCP antibodies test was <
0.01 which indicate significant difference between patients and control group .So
anti-CCP more specific and less sensitive than RF ,although it can be depended on RF
for initial diagnosis , treatment and prevention of joint disabling .Seronegative
patients did not exclude RA so must seek for another investigation such as anti-CCP.
Measuring RFand anti-CCP at the same time increase sensitivity for diagnosis.