Anaphylactic Induction of Lupus Nephritis and Posterior Reversible Encephalopathy Syndrome Following Administration of Depo-Provera.

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease in which environmental and medication-related exposures may precipitate disease onset or flares in susceptible individuals, which can result in lupus nephritis (LN) and, in rare cases, posterior reversible encephalopathy syndrome (PRES). Immediate hypersensitivity reactions preceding the initial presentation of SLE have rarely been described. We report that a 21-year-old Hispanic woman developed airway-compromising angioedema, encephalopathy, and generalized tonic-clonic seizures, requiring intubation after her first depot medroxyprogesterone acetate (DMPA) injection. Brain magnetic resonance imaging (MRI) demonstrated PRES with extensive posterior vasogenic edema consistent with PRES with hemorrhagic transformation and bilateral posterior cerebral artery vasoconstriction. Laboratory evaluation revealed acute kidney injury with proteinuria, hypocomplementemia, positive antinuclear and antidouble-stranded DNA antibodies, and positive SSA antibodies. Kidney biopsy confirmed class IV diffuse LN. Treatment included pulse corticosteroids, seizure prophylaxis, immunosuppressants, and antihypertensive therapy, resulting in neurological and renal recovery. Although causality cannot be inferred, the temporal sequence raises the hypothesis that immune activation associated with DMPA exposure, or hypersensitivity to one of its excipients, may have contributed to the clinical unmasking of autoimmune disease.