Kaline M C Pereira1, Atila G A Faria1, Bernadete L Liphaus2, Adriana A Jesus2, Clovis A Silva3, Magda Carneiro-Sampaio2, Luis E C Andrade4. 1. Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de São Paulo. 2. Children's Hospital and. 3. Children's Hospital and Department of Pediatrics, Disciplina de Reumatologia, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil. 4. Rheumatology Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, luis.andrade@unifesp.br.
Abstract
OBJECTIVE: Complete deficiency of Complement C4 component is a strong genetic risk factor for SLE. C4 is encoded by two different genes, C4A and C4B, which show considerable gene copy number (GCN) variation. This study investigates the association of total C4, C4A and C4B GCN with JSLE. METHODS: Ninety JSLE patients, 170 adult-onset SLE (aSLE) patients and 200 healthy individuals were evaluated for C4A and C4B GCN by quantitative real-time PCR. RESULTS: JSLE patients had lower GCN for C4A (mean = 1.7; 95% CI: 1.5, 1.9) and C4B (mean = 1.5; 95% CI: 1.3, 1.6) compared with healthy individuals (mean C4A = 2.3; 95% CI: 2.2, 2.5, P < 0.001; C4B = 2.0; 95% CI: 1.8, 2.1; P < 0.001) or with aSLE patients (mean C4A = 1.9; 95% CI: 1.8, 2.1, P = 0.006; mean C4B = 1.8; 95% CI: 1.7, 1.9, P < 0.001). Low total C4 GCN (<4 copies) was more frequent in JSLE than in healthy individuals (59% vs 28%; P < 0.001). The same was observed for low C4A (⩽1 copy) (52% vs 18%; P < 0.001) and for low C4B (60% vs 31%; P < 0.001). JSLE had a stronger association with low total C4 (OR = 3.68, 95% CI: 2.19, 6.20), C4A (OR = 4.98, 95% CI: 2.88, 8.62) and C4B (OR = 3.26; 95% CI: 1.95, 5.47) than aSLE (C4 OR = 2.03; 95% CI: 1.32, 3.13; C4A OR = 2.36; 95% CI: 1.46, 3.81; C4B OR = 1.13; 95% CI: 0.73, 1.74). In addition, pericarditis in JSLE patients was associated with low C4 (OR = 4.13; 95% CI: 1.02, 16.68; P = 0.047) and low C4A (OR = 5.54; 95% CI: 1.37, 22.32; P = 0.016). CONCLUSION: Low total C4, C4A and C4B GCN were associated with a stronger risk for developing JSLE than aSLE. Additionally, low total C4 and C4A GCN are risk factors for pericarditis in JSLE.
OBJECTIVE: Complete deficiency of Complement C4 component is a strong genetic risk factor for SLE. C4 is encoded by two different genes, C4A and C4B, which show considerable gene copy number (GCN) variation. This study investigates the association of total C4, C4A and C4B GCN with JSLE. METHODS: Ninety JSLE patients, 170 adult-onset SLE (aSLE) patients and 200 healthy individuals were evaluated for C4A and C4B GCN by quantitative real-time PCR. RESULTS: JSLE patients had lower GCN for C4A (mean = 1.7; 95% CI: 1.5, 1.9) and C4B (mean = 1.5; 95% CI: 1.3, 1.6) compared with healthy individuals (mean C4A = 2.3; 95% CI: 2.2, 2.5, P < 0.001; C4B = 2.0; 95% CI: 1.8, 2.1; P < 0.001) or with aSLE patients (mean C4A = 1.9; 95% CI: 1.8, 2.1, P = 0.006; mean C4B = 1.8; 95% CI: 1.7, 1.9, P < 0.001). Low total C4 GCN (<4 copies) was more frequent in JSLE than in healthy individuals (59% vs 28%; P < 0.001). The same was observed for low C4A (⩽1 copy) (52% vs 18%; P < 0.001) and for low C4B (60% vs 31%; P < 0.001). JSLE had a stronger association with low total C4 (OR = 3.68, 95% CI: 2.19, 6.20), C4A (OR = 4.98, 95% CI: 2.88, 8.62) and C4B (OR = 3.26; 95% CI: 1.95, 5.47) than aSLE (C4 OR = 2.03; 95% CI: 1.32, 3.13; C4A OR = 2.36; 95% CI: 1.46, 3.81; C4B OR = 1.13; 95% CI: 0.73, 1.74). In addition, pericarditis in JSLE patients was associated with low C4 (OR = 4.13; 95% CI: 1.02, 16.68; P = 0.047) and low C4A (OR = 5.54; 95% CI: 1.37, 22.32; P = 0.016). CONCLUSION: Low total C4, C4A and C4B GCN were associated with a stronger risk for developing JSLE than aSLE. Additionally, low total C4 and C4A GCN are risk factors for pericarditis in JSLE.
Authors: Evan Mulvihill; Stacy Ardoin; Susan D Thompson; Bi Zhou; Gakit Richard Yu; Emily King; Nora Singer; D M Levy; Hermine Brunner; Yee Ling Wu; Haikady N Nagaraja; Laura Eve Schanberg; Chack-Yung Yu Journal: Lupus Sci Med Date: 2019-07-31