title: Mannose-binding lectin gene polymorphisms and mycobacterial lymphadenitis in young patients.
abstract: BACKGROUND
  Tuberculosis (TB) has recently re-emerged as a major public health threat worldwide. There is strong evidence that host genetic factors influence individual susceptibility to TB and that, once infected, young children and immunocompromised patients are at increased risk for mycobacterial disease and progression to extrapulmonary lymphadenitis.
  
  
  METHODS
  The association between polymorphisms of mannose-binding lectin and the susceptibility of 139 children with cervical mycobacterial lymphadenitis and infected with Mycobacterium tuberculosis was investigated.
  
  
  RESULTS
  The frequencies of genotypes A/B and B/B, based on codon 54 polymorphisms, were significantly different in TB-infected versus healthy control subjects. The frequency of the A/B genotype was significantly lower in TB-infected children (odds ratio = 0.56; 95% confidence interval: 0.36-0.87; P = 0.01), and the B/B genotype was significantly higher in TB-infected children (odds ratio = 4.68; 95% confidence interval: 1.35-16.3; P = 0.01) compared with healthy controls. The HYB haplotype appeared significantly more often to be protective in the healthy control population (odds ratio = 0.23; 95% confidence interval: 0.05-0.96; P = 0.046). Ex vitro phagocytosis assays indicated that high-expression mannose-binding lectin genotypes are associated with an increased risk of infection with M. tuberculosis.
  
  
  CONCLUSIONS
  The present study suggests that mannose-binding lectin can protect against TB or predispose the host to the disease depending on the haplotype pair of the host. The low-expression genotype A/B and the HYB haplotype may be associated with protection against intracellular mycobacterial infections, whereas the high-expression genotype A/A may confer susceptibility to disease.
authors.affiliation: From the *Department of Laboratory Medicine, E-DA Hospital/I-Shou University; Departments of †Pathology and ‡Laboratory Medicine, Kaosiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine; and §Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Huey-Ling
authors.initials: HL
authors.lastname: You
authors.forename: Tsun-Mei
authors.initials: TM
authors.lastname: Lin
authors.forename: Jui-Chu
authors.initials: JC
authors.lastname: Wang
authors.forename: Chia-Chin
authors.initials: CC
authors.lastname: Li
authors.forename: Tsai-Ling
authors.initials: TL
authors.lastname: Chao
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Liao
authors.forename: Hock-Liew
authors.initials: HL
authors.lastname: Eng
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D060467:Disease Resistance; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D037601:Mannose-Binding Lectin / Q000235:genetics*; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011110:Polymorphism, Genetic; D014388:Tuberculosis, Lymph Node / Q000235:genetics* / Q000276:immunology*
chemical_list: D037601:Mannose-Binding Lectin