Systemic lupus erythematosus, a disease associated with low levels of clusterin/ApoJ, an antiinflammatory protein

Objective. To measure the serum levels of clusterin, an antiinflammatory pr otein, which binds and inactivates complement, in patients with systemic lu pus erythematosus (SLE) to determine whether the levels correlate with dise ase. Methods. The levels of serum clusterin were measured by ELISA in 80 patient s with SLE (76 female, 4 male). Clinical and serological information was ga thered on 115 visits. Overall disease activity scores were determined using the Systemic Lupus Activity Measure-Revised. Results, Serum clusterin levels were significantly decreased in patients wi th SLE and correlated inversely with disease activity (p < 0.00001). Low cl usterin levels were significantly associated with skin ulcers (p < 0.0001), loss of hair (p = 0.002), proteinuria (p = 0.018), low platelet count (p = 0.03), and arthritis (p < 0.0001), The clusterin levels did not correlate with either systemic complement consumption, as measured by C3 or C4, or wi th prednisone use. Conclusion. A highly significant correlation was observed between low level s of serum clusterin and a number of SLE disease features. This deficiency of clusterin could directly or indirectly affect the disease process. Indiv iduals lacking sufficient amounts of clusterin systemically likely have poo r control of antibody mediated inflammation at sites of apoptosis where aut oantigens are exposed.