Rapamycin reduces disease activity and normalizes T cell activation-induced calcium fluxing in patients with systemic lupus erythematosus

Arthritis Rheum. 2006 Sep;54(9):2983-8. doi: 10.1002/art.22085.


Objective: Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown origin. Current treatment options are often ineffective or poorly tolerated. Recent observations have revealed mitochondrial hyperpolarization and enhanced Ca2+ fluxing in T cells from SLE patients. Rapamycin, a lipophilic macrolide antibiotic that regulates mitochondrial transmembrane potential and Ca2+ fluxing, has been used safely and effectively to treat renal transplant rejection since 1999. In addition, rapamycin has been shown to ameliorate T cell function and to prolong survival in lupus-prone MRL/lpr mice. We therefore undertook the present study to investigate whether rapamycin is beneficial in patients with SLE.

Methods: Nine patients with clinically active SLE that had been treated unsuccessfully with other immunosuppressive medications began therapy with rapamycin, 2 mg/day orally. Disease activity was assessed with the British Isles Lupus Assessment Group (BILAG) score, SLE Disease Activity Index (SLEDAI), and requirement for prednisone therapy. Mitochondrial transmembrane potential and Ca2+ fluxing were assessed by flow cytometry.

Results: In patients treated with rapamycin, the BILAG score was reduced by a mean +/- SEM of 1.93 +/- 0.9 (P = 0.0218), the SLEDAI by 5.3 +/- 0.8 (P = 0.00002), and concurrent prednisone use by 26.4 +/- 6.7 mg/day (P = 0.0062) compared with pre-rapamycin treatment. While mitochondrial hyperpolarization persisted, pretreatment cytosolic and mitochondrial Ca2+ levels and T cell activation-induced rapid Ca2+ fluxing were normalized in rapamycin-treated patients.

Conclusion: Rapamycin appears to be a safe and effective therapy for SLE that has been refractory to traditional medications. Mitochondrial dysfunction and Ca2+ fluxing could serve as biomarkers to guide decisions regarding future therapeutic interventions in SLE.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Anti-Bacterial Agents / therapeutic use
  • Calcium Signaling / drug effects
  • Calcium Signaling / physiology*
  • Cell Culture Techniques
  • Flow Cytometry
  • Humans
  • Immunosuppressive Agents / therapeutic use
  • Lupus Erythematosus, Systemic / drug therapy*
  • Lupus Erythematosus, Systemic / immunology
  • Lupus Erythematosus, Systemic / physiopathology
  • Lymphocyte Activation / drug effects
  • Male
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Middle Aged
  • Mitochondrial Membranes / drug effects
  • Mitochondrial Membranes / physiology
  • Sirolimus / therapeutic use*
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / immunology*


  • Anti-Bacterial Agents
  • Immunosuppressive Agents
  • Sirolimus