Introduction
Rheumatoid arthritis has widely been known as a highly heterogeneous
disorder of Immune dys-regulation (1,
2), Rheumatoid factor (RF) is an
autoantibody, and is been used in the diagnosis of rheumatoid arthritis
for years, recently, Anti-cyclic citrullinated peptide antibody (ACPA)
has gained more attention, as a valuable and significant marker in
predicting and diagnosing of RA (3). Both
RF and ACPA have the same sensitivity, however, ACPA much more specific
in the diagnosis of RA (4).
Nowadays, seronegative RA has become a moving target, reflecting both
new modification in RA categorization (5),
and an evolving understanding of diseases-antibodies association
(5). The proportion of the RA patients
which is reportedly sero-negative for both ACPA and RF ranges between
0.1-0.48 (6).
ACPA and RF have been recognized as poor prognostic markers of RA, and
both are used evidence to justify the use of intensive therapy in
seropositive RA patients (SPRA) (7). The
report aims to draw attention to unusual presentation of RA in a young
sero-negative patient.