Study Of Gilbert Syndrome Associated UGT1A1 Polymorphism In Jaundiced Neonates Of ABO Incompatibility Hemolysis Disease

Part1 The clinical and laboratory characteristics of ABO incompatibility hemolysis diseaseBackground:Neonatal jaundice,one of the most common manifestations to occur in neonatal period,affects about 60%of near tern or tern newborn babies.The peak serum level of total bilirubin appears about 3-5 days of age,and lasts for about 2 weeks of age.Although most cases are mild with jaundice,about 10%of cases are requiring effective phototherapy or even exchange transfusion.Because of its free serum bilirubin,which can cause complications such as kernicterus,which need to be recognized in time and treated effectively.ABO hemolytic disease of the newborn(ABO HDN)is currently the most common cause of neonatal jaundice attributed to maternal-infant blood incompatibility.Although most cases of ABO HDN are mild with jaundice as the only clinical manifestation,significant hyperbilirubinemia requiring effective phototherapy,severe hyperbilirubinemia requiring exchange transfusion.Not all of the babies whoⅦhave maternal-infant blood incompatibility have ABO HDN,and the incidence of high total serum bilirubin centration and also incidence of kernicterus are high among Asian neonates.These findings suggest that a genetic factor might be involved.Materials and Methods:A prospective analysis was conducted of 65 cases of neonatal ABO incompatibility hemolysis of tern babies admitted to our hospital from Jan,to April.2016,65 cases of ABO compatibility jaundice cases of tern babies with same age and same seru bilirubin levels as control.We compared with two groups of gestational age,age,birth weight,mode of delivery,serum bilirubin,hemoglobin,reticulocyte,COHb,r-GT,et al.Serum album levels,GPT,GOT,r-GT,TSH,COHb,Hb,reticulocyte count were compared between the two groups.The receiver operating characteristic(ROC)would be established and do statistic analysis.SPSS 13.0 were used to analysis those two groups’ datas.And independent sample t-test and the chi-square test were used as applicable.Results:There are 65 babies in the study group and 65 babies in the compare group.Neonatal details were recorded for all cases:gender,birthweight,age,gestational age,mode of delivery,discharge time of the initial meconium,times of meconium discharge,initial feeding time,physical weight loss,feeding pattern.The serum bilirubin levels and characteristics of the infants in the two groups were compared,and no statistical differences between the two groups(p>0.05).Serum album levels,GPT,GOT,r-GT,TSH,COHb,Hb,reticulocyte count were obtained whenever indicated.Among the two groups,only COHb in the ABO incompatibility group are significantly lower from the compared group.Others are no statistically significant difference between the two groups.The AUC for COHb were 0.708.When the cut-off value of COHb for optimun prediction of HDN was>1.75%(sensitivity was 80%).When the cut-off value of COHb for optimun prediction of HDN was>2.05%(specificity was 74.5%).Phototherapy and exchange transfusions were undertaken according to AAP’s chart.The incidence of exchange transfusion,phototherapy,BEAP abnormal and encephalopathy between the two groups were statistically significant difference(p<0.05).And the incidence of brain MRI abnormal were no statistically significant difference between the two groups(p<0.05).Conclusions:Excluding other factors that cause hemolysis,COHb is an early adjunctive marker for detecting neonatal ABO incompatibility hemolysis disease.Part 2 Study of Gilbert syndrome associated UGT1A1 polymorphism in jaundiced neonates of ABO incompatibility hemolysis diseaseBackground:Gilbert syndrome,a benign form of unconjugated hyperbilirubinemia,is a hereditary dysmetabolism disease and common in clinic.The oversea incidence rate is about 5-10%.The clinical manifestation is intermittent unconjugated non hemolytic hyperbilirubinemia without hepatic organic disease.Its prognosis is good,requires neither treatment nor long-term medical attention.Clinicians have not known enough about this disease;therefore,the mild hyperbilirubinemia may be mistaken for hepatic jaundice,obstructive jaundice and hemolytic jaundice and received long-term treatment,and causes patient’s unwarranted anxiety.So,it is important to make the right diagnosis in time.Hemolytic disease of the newborn is the most common disease that causes neonatal jaundice,ABO incompatibility disease is the most common disease of hemolytic disease of the newborn.It is very important to diagnose and understand the difference with other jaundice.Objective:Some studies have revealed that the combination of the Gilbert genotype with other ictergenic factors such as breast feeding,G-6-PD deficiency,ABO incompatibility and pyloric stenosis dramatically increases a newborn risk of hyperbilirubinemia and also complications such as bilirubin encephalopathy.We test the UGT1A1 gene mutation of two group neonatal babies,one group of ABO incompatibility and one group of ABO compatibility babies,and compare the rate of the mutation of the UGT1A1 gene to assess the probable relationship between icter in neonates with ABO incompatibility and Gilbert syndrome associated UGT1A1 gene polymorphism.Materials and Methods:Peripheral blood samples were collected from the study group and compared group patients,and the genomic DNA was extracted.The Phenobarbital-responsive enhancer module,TATA box and 5 exons of the UGT1A1 gene were amplified by polymerase chain reaction(PCR),and assessed the PCR product by Sepharose Electrophoresis,and analyzed the mutation of the UGT1A1 gene screened by direct DNA sequencing assays.Furthermore,flesh blood samples were collected from all the members to detect the serum biochemical test.Then we compare the rate of the mutation of the UGT1A1 gene of the two groups of babies to assess the probable relationship between icter in neonates with ABO incompatibility and Gilbert syndrome associated UGT1A1 gene polymorphism.We also compare the incidence of high bilirubinemia between babies with and without UGT1A1 mutation in the ABO incompatibility group,to determing the relationship between icter in neonates with ABO incompatibility and Gilbert syndrome associated UGT1A1 gene polymorphism.SPSS 13.0 were used to analysis those two groups’ datas.And independent sample t-test and the chi-square test were used as applicable.Results:There are 65 babies in the study group and 82 babies in the compare group.Neonatal details were recorded for all cases:gender,birthweight,age,gestational age.The characteristic of the infants in the two groups were compared,and no statistically significant difference between the two groups(p>0.05).Twenty six of the 65 infants(40%)had an identical transition allele,and 26 of the 82 infants in the compare group(32%)had an identical transition allele(p>0.05).There are no statistically significant difference of the incidence of Gly71 Arg TATA,and Tyr486Asp between the two groups of ABO HDN and non ABO HDN(p>0.05).There is statistically significant difference of the serubilirubin level between the Gly71Arg Homozygous group and no mutation group in the ABO HDN patients(p<0.05).There are no statistically significant difference o of the serubilirubin level between the TATA,and Gly71Arg Heterozygous group and no mutation group in the ABO HDN patients(p>0.05).When hyperbilirubinemia was defined as serum biliribin concentration>256μmol/L,the incidence of hyperbilirubinemia between patients of UGT1A1 and non UGT1A1 mutation in the ABO HDN group is not significantly different(p>0.05).When defined as serum biliribin concentration>342μmol/L,the incidence of hyperbilirubinemia between patients of UGT1A1 and non UGT1A1 mutation in the ABO HDN group is significantly different(p<0.05).When hyperbilirubinemia was defined as serum biliribin concentration>427μmol/L,the incidence is significantly different(p<0.05).But in the ABO HDN group,there are no signifigant difference.The incidence of UGT1A1 mutation between male and female in our study is 31:21(p>0.05),there is no statistically significant difference.Conclusions:Our study suggested that there are no statistically significant difference of the incidence of Gly71Arg,TATA,and Tyr486Asp between the two groups of ABO HDN and non ABO HDN.There is statistically significant difference of the serubilirubin level between the Gly71Arg Homozygous group and no mutation group in the ABO HDN patients.There are no statistically significant difference o of the serubilirubin level between the TATA,and Gly71Arg Heterozygous group and no mutation group in the ABO HDN patients.When hyperbilirubinemia was defined as serum biliribin concentration>342μmol/L,the incidence of hyperbilirubinemia between patients of UGT1A1 and non UGT1A1 mutation in the ABO HDN group is significantly different.