Fetal lymphocyte subpopulations in red blood cell iso-immunised pregnancies.

OBJECTIVE

To study the association between fetal anaemia and alterations in lymphocyte subpopulations.

DESIGN

Cross-sectional study.

SETTING

The Harris Birthright Research Centre for Fetal Medicine, King's College Hospital Medical School, London.

SUBJECTS: Forty-three red blood cell iso-immunised pregnancies undergoing cordocentesis at 19 to 38 weeks gestation.

MAIN OUTCOME MEASURES: Fetal blood haemoglobin concentration, erythroblast count and lymphocyte subpopulations.

RESULTS

The mean T (CD3+), B (CD19+), T-helper (CD4+), T-suppressor/cytotoxic (CD8+) and natural killer (NK: CD16+/CD56+) cell counts in the anaemic fetuses were significantly lower than the appropriate normal mean for gestation (CD3+: t = -3.25, P < 0.01; CD19+: t = -2.14, P < 0.05; CD4+: t -4.03, P < 0.001; CD8+: t = -3.39, P < 0.01 and CD16+/CD56+: t = -3.49, P < 0.01). Furthermore, there was a significant association between the decrease in T lymphocyte number and the degree of fetal anaemia (r = 0.342, P < 0.05).

CONCLUSIONS

Fetuses from red blood cell iso-immunised pregnancies exhibit nonselective lymphopenia that is proportional to the degree of anaemia.