The behaviour of the peripheral natural killer cells in the foetal growth restriction

To study the behaviour of the peripheral lymphocyte subsets in foetuses affected by growth restriction.

Thirty consecutive pregnant women with an ultrasound diagnosis of foetal growth restriction were included in this study (group A) while 30 women with a physiologic pregnancy were recruited as control group (group B). The diagnosis was performed during the ultrasound of the third trimester and confirmed at birth. Blood samples were drawn after the ultrasound of the third trimester for all patients. The analyzed populations were: WBC, total lymphocytes, CD2+, CD3+, CD4+, CD5+, CD8+, CD19+, CD56+, HLA-DR+, CD45+, CD3+HLA-DR+, CD4+CD3+, CD3+CD8+, CD2+CD56+, CD19+CD5+, ratio (CD4+CD3+)/(CD3+CD8+).

The percentage and absolute value of the NK cells was higher in the group A [(20.90 vs. 15.09)%, p = 0.0005; (419.55 vs. 341.40) UI/μl, p = 0.0005]. This trend was confirmed by the CD2+CD56+ natural killer (NK) subset [(18.84 vs. 13.42) UI/μl, p = 0.0005]. Instead, the CD4+ percentage value was lower in the group A [(41.15 vs. 44.84)%, p = 0.03] through the CD4+CD3+/CD3+CD8+ ratio was not significantly different.

Our findings reinforce the concept of pregnancy as a controlled systemic inflammatory state that if altered can have adverse consequences for the mother and the foetus.