Impact pregnancy-induced hypertension on neonatal
thrombopoiesis
Yang J, Fok T-F, Lee
C-H, Yang M, Li K-H, Ng P-C, Yuen M-P
Department of
Paediatrics, Prince of Wales Hospital,
Chinese University of
Hong Kong, Hong Kong
Objective: To
investigate the impact of pregnancy-induced hypertension (PIH) on the
mechanism of neonatal thrombocytopenia.
Methods: Eight
infants born to mothers with PIH and 7 infants born to normal mothers were
studied within 3 days of birth. Circulating megakaryocyte (MK) count and
circulating MK progenitor were quantified by whole blood infiltration
method and plasma clot culture system respectively. Immunosorbent assays (ELISA) were employed to estimate
plasma levels of thrombocytopoietin (Tpo) and Interlukin-6 (IL-6). Platelet
activation markers -CD62P, CD63 were also estimated by flowcytometry. The
two groups had similar gestation age, birth weight, postnatal age, clinical
diagnosis and therapeutic intervention.
Results: When
compared to the controls, infants born to mother with PIH had significantly
lower peripheral platelet count (131.3¡À20.8´109/L vs
227.9¡À22.5´109/L,
p=0.005), circulating MK count (5.5¡À0.8/ml vs 10.0¡À1.9/ml, p=0.045) and
circulating MK progenitors (15.5¡À2.5/1´105 cell vs
24.3¡À3.35/1´105 cell,
p=0.047); increased plasma Tpo (146.3¡À32.3 pg/ml vs 64.7¡À16.6 pg/ml, p=0.05),
IL-6 levels (108.3¡À64.1 pg/ml vs
18.7¡À5.9 pg/ml,
p=0.26), greater expressions of CD62P (16.1¡À2.4% vs 10.2¡À1.8%, p=0.045) and CD63
(15.1¡À2.3% vs 8.1¡À1.2%, p=0.027).
Conclusions: The finding
showed that maternal PIH was associated with decreased peripheral platelet
count, resulting most likely from the combine effect of impaired
megakaryocyte formation and increased platelet activation. There was
activation of a feedback mechanism mediated through cytokines such as Tpo
and IL-6.