Anaemia of chronic disease (ACD) is a frequent complication of rheumatoid arthritis (RA). A diagnostic difficulty in RA is the distinction between iron deficiency anaemia (IDA) and ACD. The aim of our study was to evaluate the usefulness of serum soluble transferrin receptor (sTfR) and sTfR/log ferritin (TfR-F) index to diagnose iron deficiency in RA patients with anaemia. Routine laboratory indices of anaemia and sTfR were measured in 20 healthy persons to form the control group, 30 patients with iron deficiency anaemia and 28 RA patients with anaemia. Serum sTfR levels were significantly elevated above the cut-off value in patients with IDA and those in the iron depleted RA subgroup (ferritin < 60 microg/L) compared with those in the control and iron repleted RA subgroup (ferritin > 60 microg/L). The same was observed for TfR-F index. However, five patients in the iron repleted RA sub group had an elevated sTfR level, of which two had increased TfR-F index. Serum sTfR correlated well with the markers of anaemia and not with ESR. Ferritin had no correlation with markers of anaemia but correlated well with ESR. Measurement of sTfR and TfR-F index are good indicators of iron deficiency in RA patients with anaemia. To be cost effective, sTfR can be estimated in RA patients with anaemia when the ferritin level is more than 60 microg/L.
Aim: Autoantibodies against cyclic citrullinated peptide (anti-CCP) are considered to be a sensitive and specific marker for rheumatoid arthritis (RA). This study evaluated the diagnostic and analytical performances of the automated anti-CCP assay.
Materials and Method: Sera from 80 patients with established RA, 65 from other rheumatic diseases (non-RA) and 55 from healthy controls were studied using second generation anti-CCP. Rheumatoid factor (RF) was also assayed in each sample, and the results were compared to the anti-CCP fi ndings. Serum pools were used to determine the precision and linearity.
Results: At a cut-off of 7.4 U/ml for anti-CCP, the sensitivity and specificity for RA were 65% and 98% respectively. RF had a sensitivity of 58% and a lower specifi city of 93 % than anti-CCP. Conclusion: The high specificity of the assay suggests that anti-CCP is useful in the diagnosis of rheumatoid arthritis and in our cohort of study population anti-CCP exhibits a better diagnostic value than RF. A considerable proportion (28%) of RF-negative RA patients were anti-CCP positive. Based on analytical performance of the assay, we conclude that full automation and high throughput features of AxSYM makes it an ideal platform for routine testing of anti-CCP.
Study site: Rheumatology clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
Chronic low back pain, defined as back pain lasting for more than three months, can be divided into mechanical or inflammatory back pain (IBP). IBP typically starts in patients below the age of 40, is improved with activity and worsens with rest. IBP is strongly associated with axial spondyloarthritis. Early recognition of IBP among primary care physicians is essential for timely diagnosis and intervention to ensure the best outcomes for patients with axial spondyloarthritis. This paper describes the Malaysian Society of Rheumatology's recently developed Inflammatory Back Pain Referral Algorithm for primary care physicians, which aims to facilitate the early identification and referral of IBP patients to rheumatologists.