Correlation Between White Blood Cells At Birth And During Bacterial Infections In Preterm Neonates With Gestational Age<32 Weeks

Objective:The aim of our study was to prospectively observe the normal level of white blood cells(WBC)count at birth in preterm neonates with gestational age(GA)<32 weeks,and to correlate the changes of WBC count during infection and recovery periods along with other laboratory parameters,such as neutrophil to lymphocyte ratio(NLR),platelet to lymphocyte ratio(PLR),monocyte to lymphocyte ratio(MLR),C-reactive protein(CRP)and platelets.Methods:This was a prospective observational study.In this study,preterm neonates with GA<32 weeks who were admitted after birth in NICU of The First Affiliated Hospital of Kunming Medical University from January 2017 to December 2018 were eligible.The WBC count of the preterm neonates was recorded on admission.Furthermore,the enrolled preterm neonates were followed and the WBC counts during infection and during recovery period along with the routine laboratory investigations were recorded.Results:A total of 149 preterm neonates with GA<32 weeks were included:59 preterm neonates with GA<30 weeks(Group 1)and 90 preterm neonates with GA 30-31+6(Group 2).1.The WBC count at birth in Group 1(preterm neonates with GA<30 weeks)was 10.03±6.795×109/L and in Group 2(preterm neonates with GA 30-31+6 weeks)was 8.971±4.736×109/L.2.The WBC count of preterm neonates with GA<32 weeks was found to be 13.840±7.577×109/L(p=0.00)during bacterial infection and 11.331±4.546×109/L(p=0.007)during recovery period.3.In preterm neonates with GA<32 weeks,NLR was 3.549±3.377(p=0.00)during infection and 1.433±1.180(p=0.00)during recovery period.It was 4.326±4.160 for culture positive infection,2.834±2.282 for clinical sepsis,3.497±2.616 for Gram positive infection and 5.243±5.511 for Gram negative infection.PLR was 75.117±59.041(p=0.00)during infection and 77.702±41.850(p=0.737)during recovery period.It was 58.202±51.770 for culture positive infection,90.661±61.667 for clinical sepsis,89.003±54.714 for Gram positive infection and 55.615±61.296 for Gram negative infection.MLR was 6.382±11.130(p=0.35)during infection and 4.637±3.471(p=0.215)during recovery period.It was 9.093±15.164 for culture positive infection,3.891±4.096 for clinical sepsis,14.110±26.408 for Gram positive infection and 11.446±16.225 for Gram negative infection.Conclusion:1.The WBC count was found to be higher in Group 1 in comparison to Group 2 in preterm neonates with GA<32.2.The WBC count of preterm neonates with GA<32 weeks increased during bacterial infection and decreased during recovery period.3.NLR can be considered as a good predictor for the bacterial infection in preterm neonates with GA<32 weeks.NLR increased during bacterial infection and decreased during recovery period but did not differentiate among culture positive infection,clinical sepsis,Gram positive and Gram negative infections.However,PLR and MLR were not significantly related during bacterial infection and recovery period.Relatively higher MLR indicated culture positive/Gram positive infection and relatively low level of PLR indicated culture positive/Gram negative infection.