[Synthetic glucocorticoid in the treatment of connective tissue diseases].
Synthetic glucocorticoids are the most potent anti-inflammatory and immunosuppressive drugs, which have been used for almost 50 years as a core drug for the treatment of connective tissue diseases. The mechanism of action of glucocorticoids as anti-inflammatory or immunosuppressive drug is considered as the repression of inflammatory cytokines, receptors of cytokines, and adhesion molecules. When 60 mg of prednisolone is administered in 3 divided doses, the plasma concentrations are around 20-30 micrograms/dl during the day time, in which condition around 90% of GC receptors are occupied. However, the concentration will decrease almost to 0 microgram/dl in the next early morning. In case of methyl prednisolone pulse therapy, about 40 micrograms/dl of the steroid is present in the next morning. These kinetics are important when we consider the glucocorticoid therapy. In the treatment of connective tissue diseases, the combination of the steroid therapy with the immunosuppressive therapy should always be considered. In diffuse proliferative lupus nephritis, glucocorticoid dosage, started at high level to suppress the clinical activity of SLE, decrease rather rapidly while cytotoxic drugs are administered at least for 2 years. In the treatment of systemic sclerosis, normotensive scleroderma kidney is treated with moderate dose of glucocorticoid and cytotoxic drugs. It is our clinical impression that low dose glucocorticoid is quite effective in the treatment of rheumatoid arthritis. However, low dose glucocorticoid therapy is effective for the patient's sense of well-being, but is scarsely effective for the articular symptoms itself and shows intense rebound phenomenon when glucocorticoid is withdrawn.