THE URINE OF SLE PATIENTS CONTAINS ANTIBODIES THAT BIND TO THE LAMININ COMPONENT OF THE EXTRACELLULAR-MATRIX

Direct immunofluorescence of tissues derived from patients affected wi th SLE demonstrates antibodies bound to the extracellular matrix (ECM) . In the present work we have tested whether such antibodies are found in the serum and urine of lupus patients and mice. We found that the urine of patients with active SLE and of MRL/lpr/lpr mice contains ant ibodies that bind ECM and that a major target for these antibodies is the 200 kDa light chain of laminin which is one of the matrix componen ts. The level of the anti-ECM, anti-laminin antibodies correlates with disease activity.