Overlap Syndrome: Systemic Lupus Erythematosus and ANCA Vasculitis in a Case Report

Introduction: Microscopic polyangiitis is a systemic necrotising vasculitis that predominantly affects small-calibre vessels. It may be associated with systemic lupus erythematosus (SLE) as part of an overlap syndrome, but there are very few reports of this in the literature.     Case Report: We report the case of a 19-year-old patient admitted with moderate haemoptysis, epistaxis and petechial purpura revealing intra-alveolar haemorrhage with a strongly positive P-ANCA. In addition, blood tests for antinuclear antibodies and rheumatoid factor were positive, with renal involvement suggesting associated lupus as part of an overlap syndrome. Progression was good with corticoide and immunosuppressant treatment. Conclusion: The clinical presentation of overlap syndrome is rare and severe, with a dual immunological profile of antinuclear antibodies and neutrophil cytoplasm.