[Relationship between L-arginine level and immunologic function in pregnant women and newborn in Guangzhou City].

OBJECTIVE

To investigate the relationship between serum L-arginine level and immune function in pregnant women and newborn in Guangzhou.

METHODS

From September 2010 to February 2011, 459 women in the third trimester of pregnancy in Guangzhou City were recruited as follow-up subjects. Demographic information, dietary intake during pregnancy and weight before pregnancy were collected through questionnaires. Serum samples in the third trimester and umbilical cord serum samples at birth were collected. The levels of L-arginine in serum were detected by liquid chromatography-mass spectrometry, the levels of cytokines interferon-γ(INF-γ) and interleukin-6(IL-6) were detected by enzyme-linked immunosorbent assay, the levels of immunoglobulins(Ig)A, IgG and IgM were detected by immunoturbidimetry. The correlation between L-arginine level and some immune indexes was analyzed by univariate analysis and multifactorial analysis.

RESULTS

The serum L-arginine level of pregnant women was(266.74±128.46) μmol/L and the level of L-arginine in umbilical cord serum was 160.00(106.50) μmol/L. The levels of IgA, IgM and IgG in umbilical cord blood were 0.068(0.013), (0.877±0.135) and(10.637±2.407) g/L respectively. The levels of IL-6 and IFN-γ in umbilical cord blood and maternal blood were 3.361(4.686), 52.531(61.387), 3.924(9.154) and 29.492(31.780) pg/mL respectively. L-arginine level in umbilical cord serum was negatively correlated with IL-6(r=-0.219, P=0.04), and positively correlated with IFN-γ(r=0.229, P=0.03) in pregnancy serum. After adjusting for factors such as the energy intake in the pregnant woman's diet, the age of the pregnant woman, the gender of the newborn, the gestational age at birth, and the birth weight and other factors, L-arginine level in umbilical cord serum were positively correlated with IgA(β=0.191, P=0.02) and IgG(β=0.191, P=0.02) levels in umbilical cord serum and IFN-γ(β=0.322, P<0.01) levels in pregnant serum.

CONCLUSION

The level of L-arginine in umbilical cord blood is positively correlated with the levels of IgA and IgG in umbilical cord blood and the level of IFN-γ in maternal blood. L-arginine level has a positive effect on immunologic function.