The present invention provides a therapeutic or prophylactic agent as a substitute for conventional steroids or immunosuppressive agents to treat or prevent systemic erythematosus, glomerulonephritis, lupus nephritis, idiopathic thrombocytopenic purpura or autoimmune anemia. The agent comprises a retinoic acid receptor agonist, specifically a retinoic acid receptor subtype .alpha. (RAR.alpha.) agonist, including for example: (1) carboxylic acid compounds having condensed rings represented by the following formula: ##STR1## (wherein the rings L and M are condensed, are the same as or different from each other, and represent an aromatic hydrocarbon which may have a substituent group or a heterocycle which may have a substituent group; the rings A and B are independent of each other and represent an aromatic hydrocarbon ring or heterocycle which may have a substituent group; and D represents a carboxyl group which may have a protective group), (2) 4-{[(3,5-bistrimethylsilylphenyl)carbonyl]amino}benzoic acid, 4-{2-[5-(3-methoxymethyl-5,6,7,8-tetrahydro-5,5,8,8-tetramethylnaphthalene -2-yl)pyrrolyl]}benzoic acid, etc.