Levels of pro-inflammatory cytokines produced from cord blood in-vitro are pathogen dependent and increased in comparison to adult controls.
BACKGROUND
Overproduction of pro-inflammatory cytokines may play a role in increased morbidity and mortality from neonatal sepsis. Objective of this study was to compare secretion of pro-inflammatory cytokines by the cord blood cells of healthy term neonates to the venous blood cells of healthy adults in vitro after stimulation with common neonatal pathogens.


METHODS
Blood samples were cultured in the presence of heat-killed group B beta-hemolytic streptococci (GBS), Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epi). Concentrations of secreted cytokines (interleukine-6, IL-6, tumor necrosis factor-alpha, TNF-alpha, interleukine-1 beta, IL-1beta and interleukine-8, IL-8) were measured after 0, 1, 2 and 4 h of incubation using chemiluminescent immunometric automated assay.


RESULTS
Blood samples from 22 neonates and 16 adults were compared. After stimulation by GBS and E. coli, cord blood cells secreted significantly higher levels of IL-6 and IL-8 than blood cells of healthy adults. In cord blood, E. coli induced secretion of higher concentration of IL-6, TNF-alpha, IL-1beta and IL-8 than S. epi, and more IL-6 than GBS; GBS induced more IL-1beta than S.epi.


CONCLUSIONS
Response of cord blood to microbial activators is different from that of adult controls. Each isolate of heat-killed bacteria induced different amount of pro-inflammatory cytokines in vitro. This may represent a useful in vitro virulence test.
Mohamed
Mohamed A
MA
Newborn Services Department, The George Washington University Hospital, Washington, DC 20037-2342, USA. mmohamed@mfa.gwu.edu
Cunningham-Rundles
Susanne
S
Dean
Charles R
CR
Hammad
Tarek A
TA
Nesin
Mirjana
M
D000328:Adult; D016207:Cytokines / Q000096:biosynthesis* / Q000097:blood / Q000378:metabolism; D004926:Escherichia coli / Q000276:immunology; D005260:Female; D005312:Fetal Blood / Q000276:immunology* / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000276:immunology*; D006094:Gram-Positive Bacteria / Q000276:immunology*; D006801:Humans; D007231:Infant, Newborn; D018836:Inflammation Mediators / Q000097:blood*; D053583:Interleukin-1beta / Q000096:biosynthesis / Q000097:blood; D015850:Interleukin-6 / Q000096:biosynthesis / Q000097:blood; D016209:Interleukin-8 / Q000096:biosynthesis / Q000097:blood; D008297:Male; D013212:Staphylococcus epidermidis / Q000276:immunology; D013292:Streptococcus agalactiae / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000097:blood; D015854:Up-Regulation / Q000276:immunology*
D016207:Cytokines; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha