Lower antibody levels to Staphylococcus aureus exotoxins are associated with sepsis in hospitalized adults with invasive S. aureus infections.
BACKGROUND
Staphylococcus aureus has numerous virulence factors, including exotoxins that may increase the severity of infection. This study was aimed at assessing whether preexisting antibodies to S. aureus toxins are associated with a lower risk of sepsis in adults with S. aureus infection complicated by bacteremia.


METHODS
We prospectively identified adults with S. aureus infection from 4 hospitals in Baltimore, MD, in 2009–2011. We obtained serum samples from prior to or at presentation of S. aureus bacteremia to measure total immunoglobulin G (IgG) and IgG antibody levels to 11 S. aureus exotoxins. Bacterial isolates were tested for the genes encoding S. aureus exotoxins using polymerase chain reaction (PCR).


RESULTS
One hundred eligible subjects were included and 27 of them developed sepsis. When adjusted for total IgG levels and stratified for the presence of toxin in the infecting isolate as appropriate, the risk of sepsis was significantly lower in those patients with higher levels of IgG against α-hemolysin (Hla), δ-hemolysin (Hld), Panton Valentine leukocidin (PVL), staphylococcal enterotoxin C-1 (SEC-1), and phenol-soluble modulin α3 (PSM-α3).


CONCLUSIONS
Our results suggest that higher antibody levels against Hla, Hld, PVL, SEC-1, and PSM-α3 may protect against sepsis in patients with invasive S. aureus infections.
Integrated BioTherapeutics Inc, Gaithersburg, MD, USA.
Rajan P
RP
Adhikari
Adebola O
AO
Ajao
M Javad
MJ
Aman
Hatice
H
Karauzum
Jawad
J
Sarwar
Alison D
AD
Lydecker
J Kristie
JK
Johnson
Chinh
C
Nguyen
Wilbur H
WH
Chen
Mary-Claire
MC
Roghmann
D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D001426:Bacterial Proteins / Q000276:immunology; D015331:Cohort Studies; D005098:Exotoxins / Q000276:immunology*; D005260:Female; D006760:Hospitalization; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D018805:Sepsis / Q000276:immunology / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000276:immunology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000276:immunology* / Q000378:metabolism
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D005098:Exotoxins; D007074:Immunoglobulin G