Systemic Lupus Erythematosus and Myasthenia Gravis: A Rare Association

Systemic lupus erythematosus (SLE) and myasthenia gravis (MG) are two autoimmune diseases that have a higher incidence in young females, relapsing–remitting course, and positive antinuclear antibodies. SLE and MG are two different clinical syndromes, which can coexist or precede each other; however, their occurrence in the same patient is rare. We report a 38-year-old female with biopsy-proven lupus nephritis on steroids and cyclophosphamide, later developed MG. Nerve conduction studies showed the decremental response of 15%–25% over facial muscles with no decremental response over limb muscles. Although antianticholinesterase receptor (AchR) antibodies were negative, she was treated with oral pyridostigmine 60 mg twice daily and clinical improvement of ocular symptoms was seen within 48 h. At present, she is on oral prednisolone and mycophenolate mofetil with follow-up creatinine of 1.4 mg/dl and no neurological symptoms.