Serum Matrix Metalloproteinase-3 in Adult and Juvenile SLE Patients in Relation to Arthritis and Nephritis

Introduction: Matrix metalloproteinases (MMPs) play an important role in the development and progression of vascular lesions. They are members of endopeptidases that are capable of degrading many extracellular matrix components, basement membrane as well as extracellular matrix surrounding cells. It is known that MMPs have been implicated in the tissue remodeling, which accompanies inflammation, bone resorption, wound healing, thrombosis and atherosclerosis. Matrix met- alloproteinase-3 (MMP-3) levels are elevated in patients with different rheumatic diseases. MMP-3 may not be primarily involved in the initial tissue damage in systemic lupus erythematosus (SLE), but rather participates in a later aspect of inflammation involving tissue repair. Aim of the Study: Was to assess and compare the serum level of MMP-3 of adult and juvenile SLE patients. Correlation of serum level of MMP-3 with clinical and laboratory mani- festations as well as Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology Damage Index (SLICC/ACR DI) were studied. Comparison of the serum MMP-3 level in patients with current arthritis and others without history of arthritis was considered. The association of lupus nephritis with MMP-3 was also well thought-out. Patients and Methods: Thirty two female SLE patients were included in the present study. They were 24 adult and 8 children all fulfilling the updated American College of Rheumatology (ACR) revised criteria for the classification of SLE. All patients were recruited from the Rheumatology and Rehabilitation and Internal Medicine Departments and Out- patient Clinics of Cairo University Hospitals. Patients were recruited into two groups, group 1 including SLE patients with present arthritis with or without past history of arthritis and group 2 including patients with no history of arthritis. Full history taking, thorough examination, laboratory and relevant radiological investigations were performed for all the patients. Twenty age and sex matched subjects (12 adults and 8 children) were considered as a control group for the corresponding patients. Serum MMP-3 was measured by ELISA in all subjects. Anti-nuclear antibody and Anti ds- DNA were carried out by indirect immunofluorescence (IIF) technique and rheumatoid factor by semiquantitative latex agglutination test in all patients. Results: The serum level of MMP-3 in the SLE patients ranged from 30 to 290 ng/ml (mean 82.5±52.58 ng/ml), in adult SLE patients it ranged from 30 to 150 ng/ml (mean 66.46±29.69 ng/ml) and in juvenile SLE it ranged from 40 to 290 ng/ml (mean 130.63±76.27 ng/ml). All the control subjects, serum MMP-3 level ranged from 5.4 to 13 ng/ml with a mean of 9.04±2.41 ng/ml. The serum level in the SLE patients was significantly higher than from the control subjects (p=0.000). On comparing the serum level of MMP-3 between adult and juvenile SLE patients, the difference was significant (p=0.007). The mean serum MMP-3 level in SLE patients with arthritis (119.06±62.24 ng/ml) was significantly higher than in those without any (62.19±35.5 ng/ml) (p=0.004). On considering the patients with lupus nephritis, the mean serum MMP-3 level was significantly higher than in those without any history, clinical or laboratory evidence of nephritis (p=0.041). The serum MMP-3 level significantly correlated with the ESR, WBC and platelet count in the SLE patients. Both indeces, SLE DAI and SLICC/DI, showed a significant positive correlation with the serum MMP-3 level only in adults (p=0.011 and 0.013 respectively).