C4A and systemic lupus erythematosus: The patient met the criteria for systemic lupus erythematosus (SLE) according to The Systemic Lupus International Collaborating Clinics (SLICC), satisfying a minimum of four criteria, including at least one of the clinical criteria (chronic cutaneous lesions) and at least one of the immunologic criteria (ANA level above the reference range, reduced C4 complement level, positive Coombs’ test in the absence of haemolytic anaemia) [4].