Toll-like Receptor Polymorphisms and Tuberculosis Susceptibility:A Comprehensive Meta-analysis

The polymorphisms of toll-like receptor（TLR） have been hypothesized to affect the tuberculosis susceptibility. However, the direct evidence remains controversial. Here we performed a comprehensive meta-analysis to summarize the associations between TLR polymorphisms and tuberculosis susceptibility. We systematically searched the Pub Med, Embase, Cochrane library, and Chinese National Knowledge Infrastructure up to April 25, 2014. Case-control studies investigating TLR polymorphisms and tuberculosis susceptibility were included in the meta-analysis. Pooled odds ratios and corresponding 95% confidence intervals were calculated for cases and controls. Stata 11.0 and Review Manager 5.1 were adopted to conduct statistical analysis. We included 29 studies, involving 17 804 individuals. The results revealed an obvious increase of tuberculosis risk in TLR2 2258 AA, and decreased risk in TLR6 745 TT and TLR8 rs3761624 GA genotypes. Meanwhile, different genetic models were performed. TLR8 rs3764879 C, TLR8 rs3761624 A and TLR8 rs3764880 A alleles were associated with high susceptibility, while TLR6 745 T and TLR8 rs3788935 C alleles were protective. Other polymorphisms, including TLR9 1486C/T, did not show significant associations with tuberculosis infection. Finally, subgroup analysis in TLR8 rs3764880 according to gender found a slight elevated effect of A allele in males. The meta-analysis suggests significant associations between several TLR polymorphisms and tuberculosis, including TLR2 2258G/A, TLR6 745C/T, TLR8 rs3761624, TLR8 rs3764879, TLR8 rs3761624 and TLR8 rs3764880. This study serves as the framework for additional studies to determine further the role of TLRs in tuberculosis infection.

Molecular epidemiology of respiratory syncytial virus

Objective To determine the epidemiologic pattern of subgroups A and B and genotypes of respiratory syncytial virus (RSV) during two noncontinuous epidemics during 1990-1991 and 1997-1998 in Beijing Methods Nasopharyngeal secretion (NPS) samples of RSV positive or RSV isolates tested by indirect immunofluorescence (IIF) assay were classified into subgroups A and B Isolates of RSV were divided into at least six different lineages, designated NP1 NP6, by restriction mapping of the N gene Np1, 3 and 6 were given by subgroup B isolates, while NP2, 4 and 5 were given by subgroup A isolates Strains of subgroup A were further subdivided into six lineages SHL1 SHL6 on the basis of the SH gene sequence SH lineages were closely related to each other and to NP1 NP6 Strains of SHL1, 3 and 4 were closely related and belonged to NP2, SHL2 and 6 to NP4, and SHL5 to NP5 Results Of 145 RSV NPS samples from the 1997-1998 epidemic, 83 (57 2%) were of subgroup B RSV positive, 62 (42 8%) of subgroup A RSV positive The rate of occurrence of subgroup A to B strains was about 1∶1 3 Two of 10 isolates during the epidemic were subgroup A strains, whereas 8 were subgroup B strains The rate of occurrence of subgroup A to B strains was 1∶4 Eight subgroup A strains of 10 isolates from the 1990-1991 epidemic were dominant; the proportion of subgroup A to B strains was 4∶1 With 10 RSV isolates in 1997-1998, all 2 subgroup A strains gave N gene fragment restriction pattern NP4, and fell into SH lineage SHL2, whereas 8 subgroup B strains all belonged to NP3 All 8 subgroup A isolates from the 1990-1991 epidemic gave pattern NP4, and fell into SHL2, while 2 subgroup B strains all belonged to NP3 The classification of subgroups A and B deduced from NP patterns corresponded to the definition of these subgroups by monoclonal antibodies Conclusions These observations confirm that subgroups A and B or multiple lineages of RSV co circulated in Beijing, but different genome types predominated each year Moreover, very similar viruses were isolated up to more than 5 years ago, indicating that despite apparent diversity of the subgroup A strains, the separate lineages might be relatively stable