The Clinical Study Of Eosinophilia In Preterm Infants During The Early Postnatal Period

1.Background and Objection1.1 BackgroundEosinophil(EOS)is a kind of multifunctional cell,it can produce a variety of pro-inflammatory mediators,cytokines and immune regulatory molecules after activated,which can play a role in a variety of physiological and pathological processes and participate in the occurrence and development of a variety of diseases.Neonatal eosinophilia was defined when the absolute value of eosinophils in peripheral blood after≥0.700×109/L,it could be further divided into mild increase:0.700×109/1-0.999×109/L;Moderate increase:1.000×109/1-2.999×109/L;Increased severity:≥3.000x109/L.And it is a common phenomenon in the neonatal period with an incidence ranging from 14%to 76%,Eosinophil in premature infants is more likely to occur due to many factors,and its clinical manifestations are varied,without specificity,and prone to missed diagnosis and misdiagnosis,severe eosinophilia in premature infants can cause tissue and organ damage.On the other hand,eosinophilia has been studied in adults and children,however,there are relatively few studies of eosinophilia in neonates in China,especially about premature infants.At present,the exact incidence,causes,pathogenesis and clinical significance of premature eosinophilia are still unknown,the cause and role of eosinophilia remains a common diagnostic challenge in neonatal intensive care unit.Therefore,we should pay more attention to the cause of premature eosinophilia and its possible relationship with later disease.1.2 ObjectionThis study was intended to assess the eosinophil count of hospitalized premature infants in the early postnatal period(7 weeks),to assess the pattern of eosinophil changes in this population and the correlation between related clinical manifestations and disease during hospitalization,in order to investigate the incidence of eosinophilia in premature infants,the causes and the clinical characteristics of related diseases,so as to provide clinicians with some clinical treatment ideas and open up clinical thinking.2.MethodsSelect 242 premature infants who were born in our hospital from March 2019 to July 2019 and were hospitalized in the NICU to the research.They were divided into the group with eosinophilia and the group without eosinophilia.Gather relevant clinical data of hospitalized preterm infants,including preterm and the pregnant mother’s general information,clinical intervention and clinical symptoms and discharge diagnosis,collect pretrem born after 1 day,3 day and record once a week for seven weeks after peripheral blood eosinophilia absolute value,eosinophil percentage,white blood cell count and CRP.The data were collated and analyzed,and the factors related to eosinophilia in premature infants were screened out by relevant statistical methods.According to the increase degree of EOS,it was divided into the mildly increased group(n=47),the moderately increased group(n=109)and the severely increased group(n=10).And then divided into four groups according to their gestational age(GA):extremely preterm(GA<28 weeks,n=28),very preterm(28weeks≤GA<32 weeks,n=77),moderate preterm(32weeks≤GA<34weeks,n=69),and late preterm(34weeks≤GA<37weeks,n=68).According to birth weight,the preterm infants were divided into the ultra-low birth weight(weight<1000g,n=25),the extremely low birth weight group(1000g≤weight<1500g,n=59)and the low-birth weight(1500g≤weight<2500g,n=158).And then the correlation analysis was carried out for different groups.3.Results3.1 During the observation period of this study,EOS count increased with the increase of postnatal age,peaked at week 4,and began to decline at week 5.The incidence of eosinophilia in premature infants was 68.6%.3.2 ①Increasing degree of eosinophils:EOS increased in 166 cases,of which mild increase accounted for 28%,moderate increase accounted for 66%,and severe increase accounted for 6%.There were differences in gestational age,birth weight and head circumference between the groups which varying degrees of increase(P<0.05).The increase of EOS was negatively correlated with gestational age and birth weight.②Gestational age and eosinophils:In the different gestational age groups,the incidence of eosinophilia were differents(P<0.05).The average EOS count of the four gestational age groups increased from the second week,and reached its peak at the fourth week after birth in the late and mid-term premature infant groups,the peak at the fifth week after birth in the early premature infant group,and the peak at the sixth week after birth in the ultra-premature infant group,with the longest increase duration.③ Birth weight and eosinophils:In the different birth weight groups,the incidence of eosinophilia were differents(P<0.05).The average EOS count of the three birth weight groups began to increase after the second week.The very low birth weight and low birth weight groups reached the peak at the fourth week after birth,while the ultra-low birth weight group reached the peak at the fifth week after birth,with the longest increase duration.3.3 The use of EPO and human milk fortifier.UU infection or colonization,and abnormal gastrointestinal symptoms were significantly associated with increased eosinophilia in premature infants,the P values are 0.039、0.033、0.022 and 0.000 respectively.In addition,the eosinophil count in the early postnatal period was used to assist the diagnosis of UU positive results:the initial eosinophil count sensitivity was the highest(76%),and the corresponding area under the curve was also the largest(0.786).The specificity of eosinophil count on the third day after birth as an auxiliary diagnostic indicator was the highest(80%).4.Conclusions4.1 The incidence of eosinophilia in premature infants was as high as 68.6%,leading to a peak in the 4th week after birth.4.2 The degree of eosinophilia were negatively correlated with the gestational age and birth weight.4.3 Eosinophila may be associated with EPO use,UU infection or colonization,and gastrointestinal disease.