leukotriene-a4 and Tuberculosis--Meningeal

Adjunctive dexamethasone saves lives in the treatment of tuberculous meningitis but this response is influenced by the patient's LTA4H genotype. Despite less certain benefit, adjunctive dexamethasone is also frequently used in the treatment of pyogenic bacterial meningitis, but the influence of LTA4H genotype on outcomes has not been previously investigated. We genotyped the LTA4H promoter region SNP (rs17525495) in 390 bacterial meningitis patients and 751 population controls. rs17525495 was associated with susceptibility to bacteriologically confirmed bacterial meningitis (P = 0.01, OR 1.27 95% confidence interval [CI] 1.05-1.54) but did not influence clinical presentation, disease severity or survival following dexamethasone treatment.

Topics: Adult; Dexamethasone; Disease Progression; Epoxide Hydrolases; Female; Genetic Association Studies; Genetic Predisposition to Disease; Humans; Infant, Newborn; Inflammation; Leukotriene A4; Male; Middle Aged; Polymorphism, Single Nucleotide; Tuberculosis, Meningeal

Susceptibility to tuberculosis is historically ascribed to an inadequate immune response that fails to control infecting mycobacteria. In zebrafish, we find that susceptibility to Mycobacterium marinum can result from either inadequate or excessive acute inflammation. Modulation of the leukotriene A(4) hydrolase (LTA4H) locus, which controls the balance of pro- and anti-inflammatory eicosanoids, reveals two distinct molecular routes to mycobacterial susceptibility converging on dysregulated TNF levels: inadequate inflammation caused by excess lipoxins and hyperinflammation driven by excess leukotriene B(4). We identify therapies that specifically target each of these extremes. In humans, we identify a single nucleotide polymorphism in the LTA4H promoter that regulates its transcriptional activity. In tuberculous meningitis, the polymorphism is associated with inflammatory cell recruitment, patient survival and response to adjunctive anti-inflammatory therapy. Together, our findings suggest that host-directed therapies tailored to patient LTA4H genotypes may counter detrimental effects of either extreme of inflammation.

Topics: Animals; Disease Models, Animal; Humans; Inflammation; Leukotriene A4; Leukotriene B4; Lipoxins; Mitochondria; Mycobacterium Infections; Mycobacterium marinum; Polymorphism, Genetic; Polymorphism, Single Nucleotide; Promoter Regions, Genetic; Signal Transduction; Transcription, Genetic; Tuberculosis, Meningeal; Tumor Necrosis Factor-alpha; Zebrafish