title: Tag SNP polymorphism of CCL2 and its role in clinical tuberculosis in Han Chinese pediatric population.
abstract: BACKGROUND
  Chemokine (C-C motif) ligand 2 CCL2/MCP-1 is among the key signaling molecules of innate immunity; in particular, it is involved in recruitment of mononuclear and other cells in response to infection, including tuberculosis (TB) and is essential for granuloma formation.
  
  
  RESULTS
  We identified a tag SNP for the CCL2/MCP-1 gene (rs4586 C/T). In order to understand whether this SNP may serve to evaluate the contribution of the CCL2 gene to the expression of TB disease, we further analysed distribution of its alleles and genotypes in 301 TB cases versus 338 non-infected controls (all BCG vaccinated) representing a high-risk pediatric population of North China. In the male TB subgroup, the C allele was identified in a higher rate (P = 0.045), and, acting dominantly, was found to be a risk factor for clinical TB (P = 0.029). Homozygous TT genotype was significantly associated with lower CSF mononuclear leukocyte (ML) counts in patients with tuberculous meningitis (TBM) (P = 0.001).
  
  
  CONCLUSIONS
  The present study found an association of the CCL2 tag SNP rs4586 C allele and pediatric TB disease in males, suggesting that gender may affect the susceptibility to TB even in children. The association of homozygous TT genotype with decreased CSF mononuclear leukocyte (ML) count not only suggests a clinical significance of this SNP, but indicates its potential to assist in the clinical assessment of suspected TBM, where delay is critical and diagnosis is difficult.
authors.affiliation: Beijing Pediatric Research Institute, Beijing Children's Hospital affiliated to Capital Medical University, Beijing, China.
authors.forename: Wei-Xing
authors.initials: WX
authors.lastname: Feng
authors.forename: Igor
authors.initials: I
authors.lastname: Mokrousov
authors.forename: Bin-Bin
authors.initials: BB
authors.lastname: Wang
authors.forename: Hugh
authors.initials: H
authors.lastname: Nelson
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Jiao
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Sun
authors.forename: Si-Rui
authors.initials: SR
authors.lastname: Zhou
authors.forename: Jing
authors.initials: J
authors.lastname: Xiao
authors.forename: Yi
authors.initials: Y
authors.lastname: Gu
authors.forename: Xi-Rong
authors.initials: XR
authors.lastname: Wu
authors.forename: Xu
authors.initials: X
authors.lastname: Ma
authors.forename: Adong
authors.initials: A
authors.lastname: Shen
mesh_terms: D000293:Adolescent; D044466:Asian People / Q000208:ethnology* / Q000235:genetics*; D016022:Case-Control Studies; D018932:Chemokine CCL2 / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D002681:China / Q000208:ethnology; D005006:Ethnicity / Q000235:genetics*; D005260:Female; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics; D008297:Male; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012727:Sex Characteristics; D014390:Tuberculosis, Meningeal / Q000235:genetics; D014397:Tuberculosis, Pulmonary / Q000134:cerebrospinal fluid / Q000150:complications / Q000235:genetics*
chemical_list: D018932:Chemokine CCL2