a. It may be possible to get some idea of antibody specificity early in an
investigation, thus saving time when the need for blood is urgent.
b. A request for five units of blood is made in an emergency. The blood
specimen from the patient is tested for ABO, Rh, and antibodies. The antibody-
detection test shows two plus agglutination at RT, no agglutination at 37C, and is
negative by AGT. While this test is incubating, five units of the appropriate ABO and Rh
group are cross matched. Of the five units selected; four are agglutinated after
centrifugation at room temperature (RT) and one is not. The unagglutinated specimen
is continued through the cross match technique. At the same time, the patient's serum
is tested with the RBC panel.
c. Table 1-6 includes three antibodies that react at RT with a frequency of 75 to
90 percent: anti-P, anti-M, and anti-N. The RBCs of the patient are tested with reagent
antiserums of the three specificities. Within a short time, the information is available
that the patient is P1, NN. The RBCs that are MM or MN are agglutinated while those
that are NN are not.
d. The four incompatible units are MM or MN and the one compatible is NN.
The antibody is probably anti-M. Additional units can be tested with anti-M, and those
that are negative can be crossmatched. Meanwhile, one unit is available.
1-35. INTERPRETATION OF COMMON PANEL RESULTS
a. Some cells are positive, some negative; autocontrol negative.
(1) One or more specific antibodies are present. With single antibodies, the
pattern of reaction is often evident; however, the possibility of additional antibodies
should not be ignored. This is the reason for the crossing out of antigens described in
paragraph 1-32d, step 2.
(2) When several antibodies coexist, the reaction temperatures and reaction
strengths usually offer clues as to specificities.
(a) At RT, 18C or 4C. The antibodies most often identified by a cold
panel are Lewis, I, M, N, and P1.
(b) At 37C. Antibodies most often identified after incubation at 37C,
in saline or albumin, are the Rh antibodies, anti-KelI, -S and -s.
(c) After AGT. After addition of antiglobulin serum, almost all warm
antibodies can be detected: anti-Kell, -Duffy, -Kidd, and so forth