The development of the complement system after 28 weeks' gestation.
OBJECTIVE
To assess the levels and development of the various complement components in preterm infants, particularly among those born before 34 weeks' gestation.


METHODS
We measured the complement system's activities (CH50 and AP50) as well as its various components (C1q,r,s, C2-C9, Factor B, and properdin) in 25 preterm infants [gestational age (GA) 28-33 weeks], 35 preterm infants (GA 34-36 weeks), 50 full-term newborn infants (GA 37-42 weeks), and 49 healthy adults as control subjects.


CONCLUSIONS
The results of these studies are: (i) complement levels and activity were significantly reduced in preterm and full-term neonates when compared with adult levels, with the exception of C7 which was within the normal range in most infants. C8 and C9 were the most markedly reduced at all gestational ages. (ii) Complement levels correlated significantly with gestational age, but not with birth-weight, type of delivery, or gender. (iii) Between 28 and 33 weeks' gestation, there appeared to be almost no development of the complement system.
Wolach
B
B
Department of Paediatrics, Meir General Hospital, Sapir Medical Center, Kfar Saba, Israel.
Dolfin
T
T
Regev
R
R
Gilboa
S
S
Schlesinger
M
M
D000328:Adult; D016022:Case-Control Studies; D011415:Complement Factor B / Q000378:metabolism; D003165:Complement System Proteins / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn / Q000097:blood / Q000254:growth & development / Q000276:immunology*; D007234:Infant, Premature / Q000097:blood / Q000254:growth & development / Q000276:immunology*; D008297:Male; D011414:Properdin / Q000378:metabolism
D011414:Properdin; D003165:Complement System Proteins; D011415:Complement Factor B