OBJECTIVE: To investigate the relationship between umbilical cord blood erythrocyte index and thalasse-mia, and reveal its clinical value in the screening of thalassemia in neonates. METHODS: 2 919 cases of umbilical cord blood from neonatal who were born in Boai Hospital of Zhongshan Affiliated with Southern Medical University from July 2017 to December 2018 were collected, the routine blood tests were preformed to detect the umbilical cord blood. Thalassemia gene in peripheral blood of neonates was collected. The cut-off values of cord blood indexes were determined, and the sensitivity, specificity and other evaluation indexs were calculated. RESULTS: Among the cord blood in 2 919 neonates, 314 cases were detected out as thalassemia(positive rate: 10.76%). The average level of RBC and RDW in 2 605 children with non-thalassemia was lower than those with 314 children with thalassemia. The levels of Hb, MCV, MCH, MCHC, HCT, Hb/RBC and MCV/RBC in children with non-thalassemia were higher than those with thalassemia, and there were significant differences in the neonates between the two groups. The RBC and RDW levels of neonates in the α-thalassemia group were higher than those in the non-thalassemia group, while the levels of Hb, MCV, MCH, MCHC, HCT, Hb/RBC and MCV/RBC of neonates were lower than those in the non-thalassemia group. The levels of MCV, MCH and Hb/RBC of neonates in the β-thalassaemia group were lower than those in the non-thalassaemia group. The levels of MCV, MCH, Hb/RBC, and MCV/RBC of neonates in the complex thalassemia group were lower than those in the non-thalassemia group. When the cut-off value of MCV was set to 106.05 fl, the sensitivity was 0.548, and the specificity was 0.907, the specificity was the highest among all indexes. The area under the ROC curve of the combined diagnosis of MCH+MCV/RBC was the largest(0.807), the sensitivity was 0.710, the specificity was 0.841, the positive predictive value was 0.348, and the negative predictive value was 0.960. CONCLUSION The single indicator of umbilical cord blood red blood cells has advantages and disadvantages for the screening of thalassemia, but the combination of MCH+MCV/RBC can improve the accuracy of the screening or diagnosis of thalassemia, it also has a positive effect to the reduction of the birth rate of children with thalassemia major, which showed a high popularization value in primary hospitals.
Child ; Erythrocyte Indices ; Fetal Blood ; Humans ; Infant, Newborn ; Mass Screening ; alpha-Thalassemia/diagnosis* ; beta-Thalassemia