CD14 (C-159T) polymorphism is associated with increased susceptibility to SLE, and plasma levels of soluble CD14 is a novel biomarker of disease activity: a hospital-based case-control study

Abstract

ABSTRACTBackgroundCluster of differentiation 14 (CD14) plays a crucial role in the innate immune response of the host in protection against various pathogens. The importance of soluble CD14 in autoimmune disorders has been described in different populations. However, the role of sCD14 in systemic lupus erythematosus (SLE) is poorly understood. Further, the association of functional variants at the promoter region of the CD14 gene (−159 C>T) with susceptibility to SLE or disease severity needs to be defined.MethodsTwo hundred female SLE patients diagnosed on SLICC classification criteria and age, sex, matched healthy controls were enrolled in the present study. PCR-RFLP method was used to genotype CD14 (C-159 T) polymorphism. Plasma levels of IFN-α, TNF-α, and sCD14 were quantified by ELISA.ResultsPrevalence of mutant genotypes (CT and TT) and minor allele of CD14 (C-159T) polymorphism was significantly higher in SLE cases compared to healthy controls (CT:P<0.0001; OR=3.26, TT:P<0.0001; OR=3.39; T:P=0.0009, OR=1.62). Further, lupus nephritis patients had a higher prevalence of homozygous mutants (TT) and mutant allele (T)(TT: P=0.0002, OR=8.07; T: P=0.001, OR=1.32). SLE patients displayed significantly increased plasma sCD14, TNF-α, and IFN-α levels in comparison to healthy controls. These cytokines were significantly elevated in patients of lupus nephritis compared to those without kidney involvement. Interestingly, sCD14 levels correlated positively with SLEDAI-2K scores and 24 hours proteinuria.ConclusionCD14 (C-159T) polymorphism is associated with an increased predisposition to the development of SLE and lupus nephritis: sCD14 is a promising novel biomarker for assessing disease activity and lupus nephritis.