Renal Thrombotic Microangiopathy in a Patient With Systemic Lupus Erythematous
American Journal of Kidney Diseases
Lupus nephritis-combined thrombotic microangiopathy is a rare complication of Systemic Lupus erythematosus (SLE), associated with poor renal outcomes. The incidence of renal thrombotic microangiopathy (TMA), in patients with lupus nephritis is reported between 1% to 24%.(1) A 33-year-old female presented with suprapubic pain for the past two weeks. She did not have fever or urinary complaints. Past medical history was significant for SLE, diagnosed oneyear back when she developed arthralgia, and photosensitive malar rash. Workup revealed microcytic anemia with a hemoglobin of 8.6 mg/dL and Acute Kidney injury (AKI) with a creatinine of 2.35 mg/dL. Urine analysis showed dipstick proteinuria, hematuria, and granular casts. Hemolytic markers including Lactate dehydrogenase, peripheral smear for schistocytes and haptoglobin were unremarkable. Autoimmune work-up showed positive anti-nuclear antibodies (ANA) titers, positive anticardiolipin antibody Ig G, Ig M and B2 Glycoprotein 1 IgM. Her renal function worsened despite a trial of volume resuscitation. A presumptive diagnosis of proliferative lupus nephritis was made. However, renal biopsy showed findings consistent with thrombotic microangiopathy and moderate acute tubular injury. There was no evidence of crescent formation, diffuse proliferation or necrosis in glomeruli. Immunofluorescence was negative for immune complexes. Pulse steroid therapy and anticoagulation with warfarin was started. Plasmapheresis was considered but eventually held as TMA was limited to the kidney with no systemic involvement. Her creatinine was stabilized at 3.5 mg/dL and she was discharged on prednisone with taper and warfarin. TMA is used to describe syndromes that cause microvascular injury leading to microangiopathic hemolytic anemia, thrombocytopenia and acute renal injury. Treatment of AKI in SLE patients with TMA on renal biopsy, in the absence of TTP or HUS is difficult, in the absence of clear guidelines. The role of plasmapheresis in Lupus nephritis with kidney-limited TMA is controversial. Some recent retrospective studies suggest that plasmapheresis may have improved renal outcomes in patients with Lupus nephritis combined TMA.(2) Further studies are warranted to help in formulating the guidelines and standardizing the care to improve outcomes.
4 Suppl. 1
Alam A, Swami A, Hasan A. Renal thrombotic microangiopathy in a patient with systemic lupus erythematous. Am J Kidney Dis. 2023 Apr;81(4 Suppl. 1):S12. doi:10.1053/j.ajkd.2023.01.042