Monocyte major histocompatibility complex class II expression in term and preterm labor.
OBJECTIVE
To investigate how term and preterm labor (PTL) influence the balance between maternal proinflammatory and antiinflammatory responses as measured by expression of major histocompatibility complex (MHC) Class II on maternal monocytes and tumor necrosis factor-alpha (TNF-alpha) production by in vitro stimulation of whole blood by lipopolysaccharide (LPS).


METHODS
Blood was taken from the following women (n=118): term elective cesarean delivery or in spontaneous labor, in premature labor, or with preterm premature rupture of the membranes (PROM) at less than 32 weeks, and gestation-matched reference group. Monocyte MHC Class II expression was measured by flow cytometry using a dual-staining technique. Plasma cytokine levels were assayed using a cytometric bead array system. In vitro whole blood stimulation with LPS was also performed, and cytokine production was measured.


RESULTS
Term labor was associated with a fall in the percentage of monocytes expressing MHC Class II, compared with third trimester of pregnancy, P<.05 and a reduction in LPS-stimulated TNF-alpha production. This fall in MHC Class II was even more pronounced in PTL and preterm PROM groups compared with the reference group, P<.01.


CONCLUSIONS
There was evidence of reduced expression of monocyte MHC Class II and LPS-stimulated TNF-alpha in term and preterm labor. This pattern of reduced MHC Class II expression and reduced TNF-alpha production is known as monocyte hyporesponsiveness or immune paresis. Detection of this state may provide insights into the maternal inflammatory status and be of use in the management of women with threatened PTL or preterm PROM.


METHODS
II.
Institute for Women's Health, and Infectious Diseases and Microbiology Unit, Institute of Child Health, University College London, London, United Kingdom.
Jillian
J
Lloyd
Meredith
M
Allen
Mallika
M
Azizia
Nigel
N
Klein
Donald
D
Peebles
D016022:Case-Control Studies; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D020869:Gene Expression Profiling; D000949:Histocompatibility Antigens Class II / Q000378:metabolism*; D006801:Humans; D008262:Macrophage Activation / Q000502:physiology; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D007752:Obstetric Labor, Premature / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011446:Prospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D000949:Histocompatibility Antigens Class II; D014409:Tumor Necrosis Factor-alpha