Complement and antibody primary immunodeficiency in juvenile systemic lupus erythematosus patients

• Published in: Lupus Vol. 20; no. 12; pp. 1275 - 1284
• Main Authors: Jesus, AA, Liphaus, BL, Silva, CA, Bando, SY, Andrade, LEC, Coutinho, A, Carneiro-Sampaio, M
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.10.2011; Sage Publications Ltd
• Subjects: Adolescent; Antibodies; Antibodies, Antinuclear - blood; Autoantibodies - blood; Autoimmune diseases; Base Sequence; Binding sites; Child; Child, Preschool; Complement C1q - antagonists & inhibitors; Complement C1q - deficiency; Complement C1q - immunology; Complement C2 - deficiency; Complement C2 - genetics; Complement C4 - deficiency; Complement C4 - genetics; Complement System Proteins - deficiency; Complement System Proteins - genetics; Disease; DNA Primers - genetics; Family medical history; Female; Gene Dosage; Humans; Immune system; Immunoglobulins; Immunoglobulins - blood; Immunoglobulins - classification; Immunologic Deficiency Syndromes - complications; Immunologic Deficiency Syndromes - genetics; Immunologic Deficiency Syndromes - immunology; Infant; Infections; Lupus; Lupus Erythematosus, Systemic - complications; Lupus Erythematosus, Systemic - genetics; Lupus Erythematosus, Systemic - immunology; Male; Medical records; Mutation; Pediatrics; Sepsis; United Kingdom > UK; Brazil; United States > US; complement deficiency; antibody deficiency; primary immunodeficiency; IgA deficiency; C1q deficiency; juvenile systemic lupus erythematosus
• DOI: 10.1177/0961203311411598
• ISSN: 0961-2033

Objective: To evaluate the frequency of primary immunodeficiencies (PID) in juvenile systemic lupus erythematosus (JSLE) patients. Methods: Some 72 JSLE patients were analyzed for levels of immunoglobulin classes and IgG subclasses and early components of the classical complement pathway. Determination of C4 gene copy number (GCN) and detection of type I C2 deficiency (D) were also performed. Results: PID was identified in 16 patients (22%): C2D in three, C4D in three, C1qD in two, IgG2D (<20 mg/dl) in four, IgAD (<7 mg/dl) in three, and IgMD (<35 mg/dl) in three; one of these patients presented IgA, C2 and C4D. Two patients had low C4 GCN and two had type I C2D. Demographic data, family history of autoimmune disease and PID, JSLE clinical findings, occurrence of infections, disease activity and therapies were similar in patients with and without PID (p > 0.05). Remarkably, the median of Systemic Lupus International Collaborating Clinics/ACR-damage index (SLICC/ACR-DI) was significantly higher in JSLE patients with PID compared with patients without these abnormalities (p = 0.0033), likewise the high frequency of SLICC/ACR-DI > 1 (p = 0.023). Conclusions: A high frequency of PID was observed in JSLE patients, suggesting that these defects may contribute to lupus development. Our findings indicate that these two groups of PID should be investigated in severe pediatric lupus.