Case report: lupus nephritis with autoantibodies to complement alternative pathway proteins and C3 gene mutation.

Background: Glomerulonephritis is one of the most severe complications of lupus, a systemic disease with multi-organ involvement, with tissue damage produced mainly by complement activation. As a result of this activation, patients with active lupus present hypocomplementemia during disease flares, but C3 and C4 levels are recovered between episodes.

Case Presentation: We present a patient who suffered two lupus nephritis episodes in 5 years, achieving complete remission with treatment after both of them, but with C3 levels persistently below normal range.

Thrombotic microangiopathy associated with use of interferon-beta.

Interferon-beta is widely used for the treatment of relapsing multiple sclerosis. The drug is usually well tolerated, but autoimmune adverse effects, including kidney disease, have been reported. Only a few cases of hemolytic uremic syndrome-thrombotic microangiopathy associated interferon-alpha have been described so far, and even fewer with beta-interferon.