Neuropsychiatric lupus erythematosus with neurogenic pulmonary edema and anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor limbic encephalitis: a case report

BACKGROUND: Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune inflammatory disease predominantly found in women of child-bearing age. Neurogenic pulmonary edema (NPE) is a recalcitrant complication that occurs after injury to the central nervous system and has an acute onset and rapid progression. Limbic encephalitis is an inflammatory encephalopathy caused by viruses, immune responses, or other factors involving the limbic system. NPE caused by SLE is rare. CASE PRESENTATION: Here, we report a case of a 21-year-old woman with SLE who experienced five episodes of generalized tonic–clonic seizure after headache and dyspnea. Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) 2 antibody was tested positive in the serum and cerebrospinal fluid. Electrocardiography (EEG) indicated paroxysmal or sporadic medium amplitude theta activity. In addition, chest computed tomography (CT) showed multiple diffuse consolidations and ground-glass opacities. We finally considered a diagnosis of NPE and AMPAR limbic encephalitis. The patient's symptoms improved obviously after methylprednisolone pulse therapy and antiepileptic treatment. CONCLUSIONS: NPE can be a complication of neuropsychiatric lupus erythematosus (NPSLE). AMPAR2 antibodies may be produced in NPSLE patients, especially in those with high polyclonal IgG antibody titers. More basic and clinical studies are required to confirm these observations and elucidate the pathogenicity of encephalitis-related autoantibodies in SLE patients.