INTRODUCTION: Systemic lupus erythematosus (SLE) is characterized by periods of clinical flares and remission that are followed by alterations of sera specific autoantibodies such as anti-dsDNA, present in 40% of the cases and strongly associated with renal involvement. Recently, there was a description of two subpopulations of anti-lipoprotein lipase antibodies (anti-LPL) in SLE: with and without anti-dsDNA activity. A possible relationship between these antibodies with inflammatory activity of SLE was not analyzed. OBJECTIVES: To evaluate longitudinally the association between anti-LPL with lupus activity in patients persistently negatives for anti-dsDNA antibodies. PATIENTS AND METHODS: Five SLE patients with persistently negative anti-dsDNA measured by ELISA and indirect immunofluorescence using crithidia luciliae and high titers of anti-LPL by ELISA (> 5 SD) were selected and followed for at least 2 years. RESULTS: Case 1: A 24-year-old male with SLE since 2001, presented with alveolar hemorrhage, proteinuria, systemic hypertension, malar rash, oral ulcers, polyarthritis, positive ANA, SLEDAI=16 and anti-LPL=144U. He was treated with intravenous (IV) methylprednisolone followed by prednisone and had an excellent response. SLEDAI=0, anti-LPL decreased to 109U. New renal flare in April 2002, SLEDAI=10 and a new increment of anti-LPL (150U). IV Cyclophosphamide and methylprednisolone were started and he achieved remission, SLEDAI=0 and a decrease of anti-LPL (77U) until become negative in 2003. Case 2: A 32-year-old female had SLE since 1997. In September 2001 began cutaneous vasculitis, fever and rash, SLEDAI=10, anti-LPL=80U. In January 2002, she had renal involvement and systemic hypertension, SLEDAI=8 and anti-LPL= 25U. She received corticosteroid and cyclophosphamide and improved. In 2003, she was asymptomatic, SLEDAI=2 and anti-LPL=12U. Case 3: A 39-year-old male has SLE since 1997. He was stable, under chloroquine use, without disease activity for 3 years, SLEDAI=0 in all period studied and no fluctuation of anti-LPL titers: 85U (2001),100U (2002) e 86U (2003). Case 4: A 58-year-old female had SLE since 1996. She was in remission since August 2001 with a SLEDAI=0 during all this study. Anti-LPL titers did not significantly change: 71U (2001), 42U (2002) e 61U (2003). Case 5: A 55-year-old female had SLE since 1989. She was stable since 2000 using chloroquine, SLEDAI=0, and anti-LPL titers without variations: 71U (1999), 92U (2001), 71U (2002) e 90U (2003). CONCLUSION: The longitudinal evaluation of the selected patients showed a positive correlation between the fluctuations of the titers of anti-LPL with the SLEDAI score. These findings suggest that this variation may be a new marker for lupus activity in patients without anti-dsDNA antibodies.
systemic lupus erythematosus; anti-lipoprotein lipase; anti-dsDNA; SLEDAI; autoantibodies
