Prediction of the Severity of Haemolytic Disease of the Newborn

Abstract

Sera containing anti-D, taken from 44 RhD-negative women with RhD-positive infants, were tested in antibody-dependent cellular cytotoxicity (ADCC) and monocyte monolayer assays (MMA) which used similar target and effector cell populations. In addition, the anti-D concentration was measured in the Auto Analyzer and the number of IgGl and IgG3 anti-D molecules bound to the target red cells was measured by flow cytometry. The results of the functional assays and AutoAnalyzer quantitation were examined for correlation with IgG subclass quantitation and all results were compared for their ability to predict the severity of haemolytic disease of the newborn (HDN). ADCC correctly predicted HDN in 39/44 (88.6%) cases, AutoAnalyzer quantitation in 35/44 (79.5%) and the MMA in 32/44 (72.7%). For all three assays, the number of correct predictions was highest when the maternal serum contained both IgGl and IgG3 anti-D. ADCC activity and HDN were correlated with the number of cell-bound IgGl molecules (r>0.58), but MMA activity was most closely correlated with the number of cellbound IgG3 molecules (r = 0.68). Hence the superior predictive value of ADCC is due to its ability to reflect the IgGl component of maternal anti-D, which has a better correlation than IgG3 anti-D with the severity of HDN.

Use of the DAF Assay to Assess the Functional Properties of Polyclonal and Monoclonal Rh D Antibodies

“…The severity of hemolytic disease of the newborn could also be predicted by such a technique, as already done by some laboratories with ADCC [33,34] and chemiluminescence [32]. The DAF technique is mainly useful to quantify the anti-D-induced phagocytosis which seems to be an impor tant mechanism involved in the clearance of sensitized RBCs during the prevention of the hemolytic disease of the newborn.…”

Assessment of the clinical usefulness of the ‘Queenan’ chart versus the ‘Liley’ chart in predicting severity of rhesus iso-immunization

“…A cut-off value of 4 iu/ml is a commonly used level above which a pregnancy may be affected (Bowell et al, 1982;Garner et al, 1995). We found that 35·1 per cent of unaffected and 46·3 per cent of mildly affected pregnancies had an anti-D level greater than 4 iu/ml, with the highest value amongst this group being 107 iu/ml.…”

Use of the DAF Assay to Assess the Functional Properties of Polyclonal and Monoclonal Rh D Antibodies

“…During the first experiments, high backgrounds were always obtained which were due to the presence o{FCS. Toprevent ADCC and Phagocytosis Assessment ofAnti-D Antibodies Vox Sang 1996;71: [30][31][32][33][34][35][36] Table1. Natural RBCs lysis in different conditions…”

“…Vox Sang 1996;71: [30][31][32][33][34][35][36] Ducrot/Beliard/Glacet/KleiniHarbonnier/ Benmostefa/Bourel expression of these Fc receptors between different donors have already been described [13]. Accordingly, a pool of 3 donations was generally used as effector cells to limit the variations between the tests.…”

“…This described technique could be performed to control the functional activity of anti-D plasma collected from hyperimmunized donors and for the control of the different preparations of polyclonal anti-D immunoglobulins used for the prevention of feto-maternal RhD alloimmunization. The severity ofhemolytic disease ofthe newborn could also be predicted by such a technique, as already done by some laboratories with ADCC [33,34] and chemiluminescence [32]. The DAF technique is mainly useful to quantify the anti-D-induced phagocytosis which seems to be an important mechanism involved in the clearance of sensitized RBCs during the prevention ofthe hemolytic disease of the newborn.…”