The search for novel biomarkers has taken centre stage in the past decades of research in Rheumatoid Arthritis (RA). The purpose of the present study was to determine the correlation of serum matrix metalloproteinase-3 (MMP-3) with disease activity, joint damage and functional disability in patients with RA. We consecutively recruited RA patients who were under follow-up at the Universiti Kebangsaan Malaysia Medical Centre (UKMMC). Information on the RA disease characteristics were obtained from the medical records and all RA patients were
assessed for DAS28 (disease activity score based on 28 joints) and Stanford Health Assessment Questionnaire (HAQ) 8-item Disability Index (HAQ-DI). The hand radiographs of the RA patients were assessed for joint damage using the Modified Sharp Score (MSS). Serum MMP-3 levels from RA patients and healthy controls were measured using the ELISA method. We recruited a total of 77 RA patients and 18 healthy controls. The serum MMP-3 levels were significantly higher among the RA patients (p<0.05). There were significant correlations between the serum MMP3 levels and MSS (r =0.327) and HAQ-DI (r=0.256), both p<0.05. The mean serum MMP levels in RA patients with radiographic joint erosions was significantly higher than in patients without erosions (p<0.05). Likewise, the subjects with significant functional impairment i.e HAQ-DI ≥1; had significantly higher mean MMP-3 levels compared to RA patients without significant disability (p<0.05). Using multivariate analysis, HAQ-DI remained the independent predictor of serum MMP-3 in RA patients. Serum MMP-3 is a potential biomarker and predictor of radiographic joint damage and functional disability in RA.
Keywords: acquired joint deformity, matrix metalloproteinases, rheumatoid arthritis
Fine scale population structure of Malays - the major population in Malaysia, has not been well studied. This may have important implications for both evolutionary and medical studies. Here, we investigated the population sub-structure of Malay involving 431 samples collected from all states from peninsular Malaysia and Singapore. We identified two major clusters of individuals corresponding to the north and south peninsular Malaysia. On an even finer scale, the genetic coordinates of the geographical Malay populations are in correlation with the latitudes (R(2) = 0.3925; P = 0.029). This finding is further supported by the pairwise FST of Malay sub-populations, of which the north and south regions showed the highest differentiation (FST [North-south] = 0.0011). The collective findings therefore suggest that population sub-structure of Malays are more heterogenous than previously expected even within a small geographical region, possibly due to factors like different genetic origins, geographical isolation, could result in spurious association as demonstrated in our analysis. We suggest that cautions should be taken during the stage of study design or interpreting the association signals in disease mapping studies which are expected to be conducted in Malay population in the near future.