title: The Fcgamma receptor IIA-R/R131 genotype is associated with severe sepsis in community-acquired pneumonia.
abstract: Community-acquired pneumonia (CAP) can be caused by a variety of microorganisms but is most frequently associated with Streptococcus pneumoniae and gram-negative bacteria like Haemophilus influenzae. Encapsulated bacteria are able to escape phagocytosis, unless they are bound by immunoglobulin G2 subclass antibodies. These antibodies interact with Fcgamma receptor IIa (Fcgamma-RIIa), thereby facilitating opsonophagocytosis of the encapsulated bacteria. We studied the relationship between the Fcgamma-RIIa-R/H131 polymorphism and the clinical course of CAP and pathogen-specific susceptibility. Regarding methodology, the Fcgamma-RIIa genotype R/H131 was determined in 200 patients with CAP and in 313 healthy controls and was correlated with the clinical course, laboratory parameters, and causative microorganism. The Fcgamma-RIIa-R/R131 genotype was found more frequently in patients with severe sepsis (odds ratio [OR], 2.55; 95% confidence interval [CI], 1.30 to 5.00; P < 0.01). The majority of patients in this group suffered from invasive pneumococcal disease. The duration of hospital stay was longer for patients with the Fcgamma-RIIa-R/R131 genotype. Fcgamma-RIIa genotypes were not associated with an increased risk of CAP in general; however, the Fcgamma-RIIa-R/R131 genotype was found more frequently in patients with CAP caused by H. influenzae than in controls (OR, 3.03; CI, 1.04 to 9.09; P < 0.05). In conclusion, the Fcgamma-RIIa-R/R131 genotype is associated with severity of CAP and is more frequent in CAP caused by H. influenzae.
authors.affiliation: Department of Internal Medicine, St Antonius Hospital, Nieuwegein, The Netherlands. henrik.endeman@planet.nl
authors.forename: Henrik
authors.initials: H
authors.lastname: Endeman
authors.forename: Marie Claire A
authors.initials: MC
authors.lastname: Cornips
authors.forename: Jan C
authors.initials: JC
authors.lastname: Grutters
authors.forename: Jules M
authors.initials: JM
authors.lastname: van den Bosch
authors.forename: Hendrik J T
authors.initials: HJ
authors.lastname: Ruven
authors.forename: Heleen
authors.initials: H
authors.lastname: van Velzen-Blad
authors.forename: Ger T
authors.initials: GT
authors.lastname: Rijkers
authors.forename: Douwe H
authors.initials: DH
authors.lastname: Biesma
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019943:Amino Acid Substitution / Q000235:genetics; D017714:Community-Acquired Infections / Q000235:genetics* / Q000276:immunology; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D018410:Pneumonia, Bacterial / Q000235:genetics* / Q000276:immunology; D011110:Polymorphism, Genetic; D017452:Receptors, IgG / Q000235:genetics*; D018805:Sepsis / Q000235:genetics* / Q000276:immunology
chemical_list: C080568:Fc gamma receptor IIA; D017452:Receptors, IgG