Antiphospholipid antibodies inhibit prostaglandin release by decidual cells of early pregnancy: possible involvement of extracellular secretory phospholipase A2.
OBJECTIVE
To investigate the effect of antiphospholipid antibodies on eicosanoid production by human decidual cells and the in vitro interaction between antiphospholipid antibodies and secretory phospholipase A2.


METHODS
Cultures of human decidual cells from early pregnancy.


METHODS
All decidual specimens were obtained from the Obstetrics and Gynecology Department of the Catholic University, Rome, Italy.


METHODS
Patients were undergoing operative laparoscopy for extrauterine pregnancy, with a period of amenorrhea ranging from 6 to 9 weeks.


METHODS
Decidual samples were collected at laparoscopy by routine uterine curettage.


METHODS
Decidual cells were incubated with antiphospholipid antibodies, and eicosanoids (prostaglandin [PG] E2, PGF2alpha, and thromboxane B2) were assayed by RIA after 24 hours of culture. In vitro interactions between antiphospholipid antibodies and secretory phospholipase A2 were investigated with use of a modified ELISA for phospholipase A2.


RESULTS
Antiphospholipid antibodies reduced eicosanoid release from decidual cells in a dose-dependent fashion. In vitro assays showed that antiphospholipid antibodies bound secretory phospholipase A2 and that a competition occurred between antiphospholipid antibodies and secretory phospholipase A2 for the common substrate cardiolipin.


CONCLUSIONS
In light of the critical role played by eicosanoids in decidual function, we suggest that an interaction between antiphospholipid antibodies and secretory phospholipase A2 occurring in vivo might impair important cellular communications at the decidual level in the antiphospholipid antibody syndrome.
Pierro
E
E
Istituto di Ginecologia ed Ostetricia, Università Cattolica S. Cuore, Rome, Italy.
Cirino
G
G
Bucci
M R
MR
Lazzarin
N
N
Andreani
C L
CL
Mancuso
S
S
Lanzone
A
A
Navarra
P
P
D017153:Antibodies, Anticardiolipin / Q000276:immunology; D017152:Antibodies, Antiphospholipid / Q000097:blood*; D001667:Binding, Competitive; D003429:Cross Reactions; D017077:Culture Media, Conditioned; D003656:Decidua / Q000166:cytology*; D005260:Female; D006801:Humans; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D011247:Pregnancy; D011453:Prostaglandins / Q000378:metabolism*