Early Prediction of ABO HDN Using Immuno-Hematological and Biochemical Tests

Abstract

Objective: ABO hemolytic disease of the newborn (ABO HDN) is the most common cause of neonatal jaundice due to feto-maternal incompatibility. The objective of this study is to evaluate early predictors of ABO HDN using immuno-hematological and biochemical tests.

Materials and methods: Newborns with blood group A/B born to group O mothers were prospectively enrolled in the present study. Direct antiglobulin test (DAT) and cord blood bilirubin (CBB) were performed. Total serum bilirubin (TSB) was measured at 72 hours of life. Serum anti-A/B IgG titers of maternal samples were measured. For the statistical analysis, Microsoft Excel 2013 (Microsoft Corporation, NY, USA) and SPSS statistical computer software (version 22) were used. To find the efficacy and cut-off values for various predictors of neonatal jaundice, receiver operating characteristic (ROC) curve analysis was performed. To evaluate the relative importance of predictors for phototherapy (PT), logistic regression was used.

Results: A total of 200 ABO incompatible mother-neonate pairs were included in the present study. The incidence of ABO HDN was 10% (n=20). The number of DAT positive cases was 38 (19%). Regression analysis showed a significant influence of antibody titre, CBB and DAT on probability of phototherapy. Antibody titers ≥512 predicted severe hyperbilirubinemia with 80% sensitivity and 83% specificity; CBB ≥2.75 mg/dL had 85% sensitivity and 83% specificity.

Conclusion: High risk ABO-incompatible neonates could be identified at birth using maternal antibody titers, DAT and CBB. Early diagnosis with enhanced surveillance will help in optimum utilization of healthcare.

TABLE 1.

Baseline characteristics of study population

FIGURE 1.

Inclusion and exclusion algorithm

TABLE 2.

Clinical characteristics of neonate in relation to direct antiglobulin test and phototherapy

TABLE 3.

Relationship between antibody titer, direct antiglobulin test and phototherapy

TABLE 4.

Results of logistic regression analysis

FIGURE 2.

Predicting the risk of ABO HDN requiring phototherapy (PT). Maternal antibody titer (log), CBB and DAT as test variables and PT group as state variable (Reference no PT group); ROC=receiver operating characteristic curve; AUC=area under curve.