New prospects for treatment of lupus nephritis.

Systemic lupus erythematosus (SLE) is envisioned to arise from hyperactivate helper T-cells that cause polyclonal B-cell secretion of pathogenic autoantibodies and formation of immune complexes which deposit in sites such as the kidney. The most widely used immunosuppressive drugs, notably corticosteroids and cyclophosphamide, are often criticized as being nonspecific. In fact, these agents may be effective in SLE and lupus nephritis because broad, rather than highly selective, effects are required to control the aberrant immune system. Nonetheless, these agents are not uniformly effective and are associated with substantial toxicities. The lack of universal efficacy raises the specter that lupus is a heterogeneous disorder with different etiopathogenesis in different subsets of patients (as in lupus-prone mice). Therapeutic prospects for the upcoming millennium include new forms and combinations of chemotherapeutic agents (mycophenolate and adenosine analogues), attempts to achieve immunological reconstitution using near-ablative chemotherapy (with or without bone marrow or stem cell rescue), monoclonal antibodies, and other inhibitors of T-cell costimulatory pathways (e.g., anti-CD154 and/or CTLA4-Ig). The prospect for gene therapy has already been realized in some animal models of SLE. In human SLE, the feasibility of gene therapy will depend on further definition of lupus-promoting genes and availability of methods to establish stable expression of potentially corrective genes.