Association between SLE nephritis and polymorphic variants of the CRP and Fc gamma RIIIa genes

• Objectives. To study the relationship between clinical manifestations in systemic lupus erythematosus (SLE) with polymorphisms in suggested susceptibility genes encoding Fc gamma RIIa, Fc gamma RIIIa, Fc gamma RIIIb, CRP and IL-1Ra. Methods. Genetic polymorphisms were analysed in 323 unrelated SLE patients and 200 healthy blood donors. The genotype frequencies were compared between clinical subsets of SLE patients, as well as with healthy controls. Clinical manifestations included the ACR classification criteria. Nephritis was further classified according to WHO class on renal biopsy. Results. Presence of a CRP4 A-allele was associated with SLE nephritis (P< 0.01) and inversely correlated with arthritis (P < 0.01), when comparing within the SLE group. The Fc gamma RIIIa F/F genotype was also associated with nephritis (WHO class III and IV, P=0.04 for the SLE group) and in combination with the CRP4 A-allele a stronger association was noted (P<0.001). Furthermore, the Fc gamma RIIIb NA2/NA2 genotype was associated with butterfly rash (P< 0.01). An association was found between seizures and the presence of both the Fc gamma RIIa R/R and the Fc gamma RIIIa F/F genotypes (P< 0.01) and an inverse correlation between serositis and the CRP4 A-allele when present together with the IL-1Ra 2-allele (P=0.01). Furthermore, a combination of the Fc gamma RIIa R/R genotype and CRP4 A-allele was associated with lymphopenia (P= 0.02) and a similar result was found for the combination of Fc gamma RIIIa F/F and Fc gamma RIIIb NA2/NA2 (P= 0.04). Conclusions. Polymorphic variants of the CRP and Fc gamma-receptor genes are associated with the clinical phenotype in SLE. Our findings suggest an immune complex-mediated pathogenesis in nephritis and seizures, while development of arthritis may depend on other pathogenetic pathways.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Reumatologi och inflammation (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Rheumatology and Autoimmunity (hsv//eng)

Nyckelord

polymorphism

genetic

Fc receptor

systemic lupus erythematosus

C-reactive protein

glomerulonephritis

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)