Efficacy of Belimumab for active lupus nephritis in a young Hispanic woman intolerant to standard treatment: a case report.

Background: Lupus nephritis (LN) is a frequent severe complication of Systemic Lupus Erythematosus (SLE), especially in patients of non-Caucasian ethnicity. Induction treatment for LN consists in the combination of steroids plus a second agent (cyclophosphamide or mycophenolate mofetil) or, as a second-line, calcineurin inhibitors or Rituximab. Induction treatment for LN can be complicated by a series of side effects, the most severe being serious infections. Belimumab is a fully humanized monoclonal antibody that targets soluble B lymphocyte stimulator (BLyS), approved for treatment of serologically active SLE in addition to standard of care.

Case Presentation: A young Hispanic woman was diagnosed with SLE at the age of 15. After several immunosuppressive treatments for arthritic symptoms (high-dose steroids, mycophenolate mofetil, Rituximab, cyclophosphamide) leading to serious complications and scarce clinical improvement, she developed severe LN. Induction treatment with a combination of intravenous high-dose methylprednisolone and cyclophosphamide was started but, after few days, the patient developed cryptococcal meningitis. After institution of appropriate antifungal therapy, treatment with Tacrolimus was attempted but poorly tolerated by the patient and withdrawn. Eventually, Belimumab was initiated off-label as a last resource to treat LN. Belimumab was well tolerated by the patient and resulted in a rapid and marked improvement in clinical symptoms and reduction in proteinuria, serum complement levels and anti-dsDNA titer; of note, the patient developed no infectious complications.

Conclusions: We report the case of a severe LN in a young Hispanic woman who did not respond to conventional and second-line induction therapies, due both to intolerance and to the development of serious infectious complications. Eventually, Belimumab was successfully added to steroids and was well tolerated by the patient, resulting in a marked improvement in clinical and biochemical parameters. We suggest that Belimumab should be considered as a potentially efficacious treatment in patients with LN who cannot tolerate conventional therapies.