Background: Weak expression of ABO antigens in newborns has been known
for many years. In the near future reduced availability of polyclonal
sera for ABO testing is to be expected. Therefore, it was the aim of
our study to compare the suitability of monoclonal reagents for ABO te
sting of newborns to that of polyclonal sera. Material and Methods: On
e monoclonal and 1 polyclonal reagent of each of the specificities ant
i-A, anti-B and anti-AB from 7 manufacturers were tested by titration
with blood from 5 newborns of blood group A, 5 of blood group B, and 3
of blood group AB. Results: All monoclonal anti-A reagents showed bet
ter results than the polyclonal sera (for newborns of blood group A on
the average of the 7 pairs of reagents 1.3 geometrical titration step
s). Most of the monoclonal anti-B reagents showed higher titers than t
he polyclonal sera (on the average for newborns of blood group B 0.7 t
itration steps), Also most monoclonal anti-AB reagents were stronger t
han the polyclonal sera in testing newborns of blood group A (on the a
verage 1.0 titration steps), but for newborns of blood group B the mon
oclonal anti-AB-reagents were slightly weaker than the polyclonal sera
(on the average 0.4 titration steps). Conclusion: Use of monoclonal r
eagents for ABO testing of newborns shows some advantages in compariso
n to the use of polyclonal sera.