RAJKUMAR T1, VILAYUR E1,2, NANRA R1,2
1Department of Nephrology, John Hunter Hospital, Newcastle, New South Wales; 2The University of Newcastle, Newcastle, New South Wales
Background: Thrombotic microangiopathy (TMA) is clinically characterised by thrombocytopenia and microangiopathic haemolytic anaemia. Systemic lupus erythematosus (SLE) may present with TMA. Differentiating a primary TMA syndrome from SLE can be difficult due to overlapping clinical features.
Case Report: A 17-year-old previously well female presented with one-week history of fevers and headache. Investigations revealed renal impairment, thrombocytopenia and anaemia with schistocytes on blood film. Urinalysis showed 11.46g/day of proteinuria with dysmorphic erythrocytes. Anti-nuclear antibody titre was 1:320 with negative anti-neutrophil cytoplasmic antibody, extractable nuclear antigens, anti-double stranded DNA and antiphospholipid antibodies. C3 was low.
With malignant hypertension, seizures, renal failure and bicytopenia, plasmapheresis was commenced for suspected thrombotic thrombocytopenic purpura/haemolytic uremic syndrome (TTP-HUS). Management was escalated to twice-daily plasmapheresis, haemodialysis, rituximab and corticosteroids with further clinical deterioration. Renal biopsy demonstrated TMA with positive IgA, IgM, C3, C1q and trace IgG staining, raising suspicion for SLE. ADAMTS-13 activity was normal and she remained dialysis-dependent at 6 weeks. Repeat biopsy demonstrated late-stage TMA with negative immunofluorescence staining. Renal function improved with ongoing plasmapheresis, and dialysis was stopped at 16 weeks.
Mycophenolate was added to therapy in the setting of persistent hypocomplementemia and new development of anti-cardiolipin antibody at 4 months. A third renal biopsy confirmed Class IV lupus nephritis and hydroxychloroquine was added. Thrombocytopenia resolved at 12 months and plasmapheresis was stopped. At 3 years, renal function normalised with resolution of proteinuria.
Conclusion: This case of TMA displayed features consistent with both TTP-HUS and SLE. Strong clinical suspicion and consecutive renal biopsies allowed a diagnosis of SLE to eventuate. Early recognition of evolving lupus as a clinical entity and timely institution of therapy can yield excellent outcomes.