enough period. The reaction does not usually occur once the normal protein is diluted
out to more than 1/20. The amount of protein present in RBC eluates does not seem to
be enough to give nonspecific results, so a positive result usually indicates the presence
of antibody to cephalothin or a cross-reacting penicillin antibody.
Section II. HEMOLYTIC DISEASE OF THE NEWBORN
Hemolytic disease (HDN)of the newborn results from the immune destruction of
the RBCs of the fetus and newborn by the coating of these cells with maternal lgG
antibody. Individual cases vary in severity, ranging from intrauterine death to a clinically
unapparent condition that can be detected only by serologic tests in a healthy baby.
Close communication and cooperation between the laboratory staff, the obstetrician,
and the pediatrician will greatly aid in optimal management and prevention of HDN.
It is convenient to classify the disease into three types based on the serologic
specificity of the offending antibody. In order of severity these are:
a. Rh (and Combinations of RhO). Anti-RhO(D) and combinations of RhO with
rh'(CD) or with rh"(DE).
b. "Other". Anti-hr'(c), anti-rh"(E), anti-KelI, and other lgG antibodies.
c. ABO. Anti-A, Anti-B, Anti-A, B.
2-14. MECHANISMS OF MATERNAL IMMUNIZATION
a. In hemolytic disease of the newborn (HDN) resulting from ABO
incompatibility, (ABO-HDN), the lgG anti-A, anti-B, and anti-A, B are present in the
mother's plasma without the requirement for prior immunization by foreign RBCs. Thus,
any pregnancy, including the first, may be involved.
Abbreviations and symbols used throughout this Section are as follows:
ABO-HDN = hemolytic disease of newborn, resulting from AGO incompatibility.
HDN = hemolytic disease of the newborn.
RhlG = Rh (D) immune globulin (human).
RhO-HDN = hemolytic disease of newborn, resulting from anti-RhO(D).
b. Group O mothers, when compared with group A or B mothers, are more likely
to produce lgG anti-A and anti-B. In addition, only plasma from group O persons
contains lgG anti-A, B, which is often involved in ABO-HDN. ABO-HDN is almost, but
not completely, restricted to group A1 or B babies born of group O mothers.