Cold agglutinin-induced haemolysis in association with antinuclear antibody-negative SLE

Abstract

Systemic lupus erythematosus (SLE) is a chronic relapsing autoimmune disease associated with several autoantibodies targeted to nuclear and cytoplasmic antigens. Serum antinuclear antibody (ANA) is considered an important diagnostic marker of SLE. However, 2-3% of patients with typical clinical picture of SLE may have persistently negative ANA tests. Autoimmune haemolytic anaemia (AIHA) in SLE is usually mediated by warm IgG anti-erythrocyte antibodies. Our report describes a female patient who presented with clinical manifestations of SLE including photosensitivity, joint pains and AIHA. Further workup revealed high cold IgM agglutinin titres. A comprehensive workup for infectious aetiologies was negative. Autoimmune studies revealed negative ANA, but positive anti-double-stranded DNA and antiphospholipid antibodies. Lymphoproliferative disorder was excluded by imaging studies. Initial treatment with steroids proved of little benefit; however, rituximab resulted in significant clinical improvement. To the best of our knowledge, this is perhaps the first report of ANA-negative SLE presenting with cold AIHA.