Clinical Implication of Immunohaematological Tests in ABO haemolytic disease of newborn: Revisiting an old disease

OBJECTIVE

We aimed to assess the frequency distribution of of ABO haemolytic disease of newborn (ABO-HDN) and to know the predictive value of immunohaematological tests in identifying at risk neonates.

BACKGROUND

ABO incompatibility, although a common cause of haemolytic disease of newborn, has several unaddressed issues related to it.

MATERIAL AND METHODS

A prospective study over 20 months was carried out in a tertiary care centre in South India. Blood grouping, Direct Antiglobulin test (DAT) and elution studies were performed on neonatal samples, whereas blood grouping, antibody screening and antibody titration were performed on maternal samples. In suspected cases, ABO-HDN was diagnosed after excluding other possible causes for haemolysis. The laboratory results were correlated with the clinical details to assess the predictive value of the tests.

RESULTS

Of the total 2856 pregnancies, 34% had ABO incompatibility. On testing with columnagglutination test (CAT), the overall DAT positivity and that among ABO-incompatible cases were 3.8% and 11.2%, respectively,) whereas by conventinal tube technique (CTT) it was 0.6% and 2.4% respectively. CAT was found to have higher sensitivity, and the predictive value was higher for CTT. Maternal IgG titre showed a positive linear relationship with the DAT strength and the rise in indirect bilirubin levels. The positive predictive value of combination of tests such as DAT, elution and titation was 94.12%, which was much higher than that of the individual tests.

CONCLUSION

DAT positivity is a predictor of early rise in serum bilirubin level, and a combination of tests has a better predictive value than individual tests towards development of clinically significant hyperbilirubinemia in ABO-HDN.

Odontometric parameters as a forensic tool for stature estimation among three Asian ethnicities

Background

The height of an individual in the upright posture is referred to as stature. The evaluation of the stature of an individual is an essential step in identification. Estimation of stature is commonly performed using the long bones as they positively correlate with the stature. The correlation between the dimensions of the skull, jaw and stature of an individual has been reported among specific populations. To date, only a few studies have correlated odontometric parameters with stature among populations. Teeth and oral structures can be used to estimate the stature of an individual. The objective of our study was to determine and establish a relationship to estimate the stature of individuals among three different Asian ethnicities using four odontometric parameters as a forensic tool. The Asian ethnicities chosen in our study were Malay, Indian and Chinese.

The five parameters were the height of an individual, intercanine width, interpremolar width, arc length and mesiodistal dimension of the six anterior teeth. The height was measured with the individual standing upright and barefooted. The mesiodistal width of the anterior teeth was measured at the contact points; the intercanine and interpremolar widths were measured at the cusp tips from the left to the right quadrant; the arc length was measured at the middle one-third position of the crown from the right to the left canine.

Results

The results showed that out of the four odontometric parameters, only the arc length was significantly associated with the height of the individuals among the ethnicities chosen.

Conclusion

Thus, of the four selected parameters, the arc length may be helpful in the estimation of stature among the selected Asian ethnicities. Dimensions of the teeth can be used as an adjunct to other aids in estimating the stature of an individual and hence is a vital forensic tool.