[Expression of CD21 in peripheral blood B lymphocytes of neonates].
OBJECTIVE
To study the cause of low immunologic function and insufficiency of immunoglobulin synthesis in neonates by detecting CD21 expression in B lymphocytes in different age group children.


METHODS
This study consisted of three age group children: 2-26 days (n=18), 6 months-2 years (n=12) and 3-12 years (n=17). CD21 expression in B lymphocytes was detected with flow cytometry. Serum levels of immunoglobulins were measured by immunoturbidimetry.


RESULTS
The percentage and the number of B lymphocytes expressing CD21 in the neonate group were significantly lower than in the other two age groups. The neonate group also showed lower mean fluorescence intension (MFI) of CD21. The percentage and the number of B lymphocytes expressing CD21 as well as the MFI of CD21 increased significantly with the age. The serum levels of IgA and IgM in the neonate group were noticeably lower than those in the other two age groups. The serum levels of IgA and IgM also increased significantly with the age.


CONCLUSIONS
Low CD21 expression in B lymphocytes may be related to low function of humoral immunity in neonates.
Zhang
Rong
R
Department of Pediatrics, Yangzhou First People's Hospital, Yangzhou, Jiangsu, China. meltzhang@yahoo.com.cn
Wang
Qiong-Jin
QJ
Xu
Jin-Mei
JM
Jiang
Li
L
Shou
Wei-Zhang
WZ
Yin
Yan
Y
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001402:B-Lymphocytes / Q000737:chemistry*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D017464:Receptors, Complement 3d / Q000097:blood*
D017464:Receptors, Complement 3d