Lymphocyte sensitivity assay as a marker for glucocorticoid resistance in lupus: report of two sisters with systemic lupus erythematosus

Abstract

Glucocorticoid sensitivity can be measured in vitro using the lymphocyte sensitivity assay (LSA). In this test, dexamethasone is used to inhibit the proliferation of peripheral blood mononuclear cells (PBMC) in response to mitogens. If the proliferation of PBMC is suppressed the subjects are considered to be GC sensitive; if not, they are considered to be resistant. The LSA has been used to test GC sensitivity in some inflammatory diseases but its clinical value in systemic lupus erythematosus (SLE) has not been determined. Herein, we present the results of the LSA from two sisters with SLE who had different disease outcomes. Patient 1 presented with higher disease activity and damage accrual, and poorer response to corticosteroids than patient 2. In the LSA, patient 1 had a lower dexamethasone suppression of mitogen-stimulated PBMC than patient 2 and one control subject. The LSA could be helpful in identifying patients with GC resistance, thus allowing the consideration of alternative immunosuppressive drugs.