White blood cell count as a predictor of the severity of sickle cell disease during pregnancy.
OBJECTIVE
Increasing epidemiological evidence implicates leukocytosis as a major risk factor for poor outcome in non-pregnant sickle cell disease (SCD) patients. The aim of this study was to investigate whether steady-state white blood cell (WBC) count can predict SCD-related problems in pregnancy.


METHODS
Retrospective observational study of 40 SCD pregnant women who had their antenatal care at Guy's & St Thomas' NHS Trust, London. Twenty-six women developed clinical complications related to SCD during their pregnancy (painful crisis, chest symptoms, infections, severe anaemia requiring blood transfusion, pre-eclampsia, and/or thromboembolism) and 14 remained asymptomatic. The steady-state leukocyte counts early in pregnancy were compared between the two groups and receiver operator characteristics (ROC) curve was plotted for different values of WBC.


RESULTS
Compared to asymptomatic patients, women who developed SCD-related complications had significantly higher total WBC count [11.2 x 10(9)L(-1) (SD 3.22) versus 8 x 10(9)L(-1) (2.8), p<0.01], higher lymphocyte count [3 x 10(9)L(-1) (1.62) versus 1.6 x 10(9)L(-1) (0.65), p<0.01] and higher monocyte count [0.8 x 10(9)L(-1) (0.47) versus 0.4 x 10(9)L(-1) (0.21), p<0.01]. The neutrophil count showed a similar trend but the difference did not reach statistical significance [6.6 x 10(9)L(-1) (2.29) versus 5.7 x 10(9)L(-1) (2.15), p=0.22]. The area under the ROC curve was 74% (95% CI: 56-92).


CONCLUSIONS
WBC count early in pregnancy was significantly higher in women who subsequently developed clinical problems related to SCD. The WBC may be used as a predictor of the severity of SCD in pregnancy.
Litos
Michail
M
Department of Obstetrics and Gynaecology, Guy's & St Thomas' NHS Trust, London SE1 7EH, UK.
Sarris
Ippokratis
I
Bewley
Susan
S
Seed
Paul
P
Okpala
Iheanyi
I
Oteng-Ntim
Eugene
E
D000328:Adult; D000755:Anemia, Sickle Cell / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D007962:Leukocytes; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis*; D012720:Severity of Illness Index