Ji Wei Yang, Eric Rich, Claire Saint-Cyr and Josiane Bourré-Tessier Pages 158 - 160 ( 3 )
The causal link between inherited complement deficiencies and systemic lupus erythematosus (SLE) has been well established, although it remains a rare cause of the disease. We present the case of three biological sisters with hereditary heterozygous C2 deficiency, but who differ widely in their clinical and serological manifestations. Patient 1 is 25 years old and was diagnosed with SLE at the age of 12. Further testing revealed positive ANA and anti-dsDNA, antiphospholipid syndrome (APS) and decreased C2, C3 and C4 levels. Patients 2 and 3 are 21-year-old dizygotic twins. Both have positive ANA and antiphospholipid (APL) antibodies, and decreased C2 and C4 levels. We present a case of familial heterozygous C2 deficiency with different disease phenotypes. The presence of positive APL antibodies in all 3 patients is significant, as this association has been rarely described. The variable clinical and serological manifestations among our patients further reflect the complex and multifactorial nature of SLE.
Systemic lupus erythematosus, complement deficiency, autoimmune disorders, antiphospholipid syndrome.
Rheumatology Division, Department of Medicine, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, Quebec, Rheumatology Division, Department of Medicine, Centre Hospitalier de l'Université de Montréal (CHUM), Montreal, Quebec, Rheumatology Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Montreal, Quebec, Centre Hospitalier de l’Université de Montréal, Hôpital Notre-Dame, 1560 Sherbrooke Street East, Montréal, QC H2L 4M1