V SRINIVASA1, G KAN1, V MANICKAM1, K SRIVASTAVA1, J LY1, SFAYEZ1
1Townsville Hospital, Townsville, Australia
Background: Macrophage activation syndrome (MAS) is a rare and life-threatening disorder described as a autoinflammatory phenomenon. It is a variant of haemophagocytic lymphohistiocytosis (HLH) and is associated with autoimmune disease such as systemic lupus erythematosus (SLE). MAS associated lupus nephritis is a rare entity with few reports documenting the use of mycophenolate.
Case Report: We present a case of an 18-year-old female with MAS caused by a flare of SLE. During her admission she experienced pyrexial episodes and was unwell. Investigations performed revealed proteinuria on urinary studies. Urine protein excretion rate was 1.92 grams per day. Additionally, urinary sediment was bland. Serum complement levels were reduced and autoantibodies were raised supporting a lupus flare. Further blood results revealed elevated ferritin peaking at 11000 IU/L and transaminases; Alanine transaminase and alkaline phosphatase peaked at 116 and 118 U/L respectively. Bone marrow biopsy was done and confirmed MAS. Renal biopsy was also performed but the sample was deemed to be insufficient. Based on the systemic lupus international collaborating clinics criteria (SLICC), lupus nephritis was suspected. She was initially commenced on cyclosporine but was changed to mycophenolate. Subsequently a repeat urine protein study has shown a urine protein excretion rate of 0.542 grams/day on mycophenolate therapy.
Conclusions: Diagnosis of MAS is challenging with the clinical features of active SLE and MAS associated SLE being similar. Hyperferritinaemia is acknowledged to be the most appropriate parameter to distinguish MAS associated SLE and active SLE. In patients with lupus nephritis, mycophenolate is used as a first line agent however, few reports have described its use in MAS or HLH associated SLE. Further studies are required.
Dr. Vinay Srinivasa is a advanced trainee currently working at the Townsville hospital. He is in his final year of advanced training for general medicine and is currently doing his first year of renal advanced training at Townsville hospital. He is aiming to be a dual specialist in both nephrology and general medicine. He has a special interest in Glomerulonephritis and hypertension