Therapeutic effect of 15-deoxyspergualin on the progression of lupus nephritis in MRL mice. I. Immunopathological analyses.

The effect of 15-deoxyspergualin (DSP), a newly developed immunosuppressive agent, on the development of spontaneously occurring lupus glomerulonephritis in MRL-lpr mice was examined. Administration of the drug was initiated at the age of 13 or 17 weeks, when polyclonal B cell activation and lupus nephropathy were apparent or became prominent. Treatment with DSP for up to 19 weeks of age at a dose of 2 mg/kg twice a day or 5 mg/kg daily strongly suppressed the increment of IgG-producing cell numbers in the spleen and serum levels of immune complexes and anti-DNA antibodies. Glomerular histological score estimated by light microscopy and IgG and C3 deposition in renal glomeruli were improved, compared with untreated control mice. Thus, DSP was shown to suppress the progression of polyclonal B cell activation and lupus nephropathy in MRL/lpr mice. These results suggest that DSP may be used as a therapeutic agent for systemic lupus erythematosus.