Serum YKL-40 in rheumatoid arthritis and its correlation with disease activity

ABSTRACT

To determine the serum level of YKL-40 in rheumatoid arthritis [RA] patients and to find out its correlation with the disease activity. The study was conducted on 20 RA patients recruited from the Rheumatology and Rehabilitation Department of Ain Shams University Hospitals, as well as 10 apparently healthy individuals who served as a control group. Patients with liver disease, myocardial infarction or malignancies were excluded. Also patients taking slow-acting drugs or had intra-articular injections in the previous month before the study were not included. All the patients and the controls were subjected to complete history taking, thorough clinical examination, radiological and laboratory tests. Serum YKL-40 level was measured in the patients and the controls using ELISA test. Serum YKL-40 level was significantly higher in RA patients as compared to the control group. Serum YKL-40 level showed a positive significant correlation with the disease duration, the parameters of disease activity in RA patients and with the disease severity as assessed with Larsen's radiological score. Measurement of serum YKL-40 level in RA patients is a laboratory test that can be used as a new parameter other than the conventional markers of inflammation, which are ESR and serum CRP level. Also, it helps to asses the disease activity as well as the progression and the destructive effect of the disease on the joints