Download Case Study CM

Case Study CM
Case Study CM: Initial Serological Results
Patient Name: CM
Cells vs:
Anti-A
Anti-B
Anti-D
0
0
3+
Serum vs:
A1 cells
B cells
4+
4+
Age: 18 years
Race: African American
Diagnosis: Pregnancy
DAT:
Medications: Vitamins
Transfusion History: None
0
Screen
Cell
I
II
III
Number of Pregnancies: One (current pregnancy)
LISS
37oC
4+
4+
4+
IS
4+
4+
4+
IgG
4+
4+
4+
Questions:
1. What do the patient’s initial serological results
suggest?
2. What would be your next step?
CASE STUDY CM: ANTIBODY IDENTIFICATION
Rh
MNS
D C E c e Cw
1 +
2 +
3 +
4 0
5 0
6 0
Auto
+
0
0
0
+
0
0
+
0
0
0
+
0
+
+
+
+
+
+
0
+
+
+
+
0
0
0
0
0
0
M N
0
+
+
0
+
+
+
0
+
+
0
+
P1
S s
+
0
0
+
+
0
+
+
+
0
+
+
P1
+
+
0
0
+
+
Lewis
Lea
0
0
0
+
0
+
Upon close examination, it was observed that the
reagent red cells were 4+ agglutinated following the
washing phase of the antiglobulin procedure and
prior to the addition of the IgG AHG.
3.
What classification of antibody(ies) would be
suspected in a patient with the given history and
serological results?
4.
What blood group systems should be considered
as potentially involved?
5.
What further testing should be completed?
Would testing another panel be helpful? Why or
why not?
Leb
+
+
0
0
+
0
Kell
K k
+
0
0
0
0
0
6.
+
+
+
+
+
+
Kidd
Jka
+
+
+
0
0
+
Duffy
Jkb
+
0
0
+
+
+
Fya
+
+
0
+
0
0
Serum
Fyb
0
0
0
+
+
+
IS
4+
4+
4+
4+
4+
4+
0
LISS
37oC
4+
4+
4+
4+
4+
4+
0
IgG
4+
4+
4+
4+
4+
4+
0
What recommendations would you make to the
patient’s physician regarding the management of
the pregnancy?
CC

CASE STUDY: CM
1. CM’s initial serological results indicate that her serum contains an antibody reactive at
immediate spin, after the 37oC incubation and at the IgG IAT. At this point an autologous
control has not been tested, although a direct antiglobulin test was negative.
2. The next step would be to test the serum against a panel of reagent red cells including an
autologous control. The phase and pattern of reactivity with the panel cells was consistent
with the initial antibody screening test. The autologous control was negative, suggesting the
presence of an alloantibody rather than an autoantibody.
3. The phases of the patient’s serum reactivity coupled with the fact that she does not have a
history of exposure to foreign red cells antigens suggests the possibility of naturally
occurring antibody(ies) rather than immune antibodies.
4. Blood group systems whose antibodies should be considered include the MNS, P, Lewis, I
and H systems.
5. The single, common antibody specificities directed against M, N, P1, Lea or Leb would not
explain the broad pattern of reactivity obtained with the red cell panel. A combination of the
antibodies or a more broadly reactive single antibody could, however, be present.
Typing the patient’s red cells for the common antigens in these systems may suggest possible
specificities. Additional antigen phenotyping will probably be useful as well.
Case Study: CM
Patient’s Phenotype:
D+C-E-c+e+, M+N+S-s+, P1+, Le(a+b-), K-, Fy(a-b+), Jk(a-b+)
Given the patient’s phenotype, common antibodies in the MNS, P and Lewis systems do not
appear likely. Testing another panel of random reagent red cells would not be helpful at this
point because there does not appear to be a simple antibody specificity.
Two blood group systems, the I and H systems, may contain antibodies with a broad pattern
of reactivity, reactive at the phases observed with this patient’s serum. Many laboratories
would not have anti-I or anti-H on hand to type the patient’s red cells. Testing the patient’s
serum against I negative group O cord or adult cells may be used to determine if the patient’s
serum contains anti-I. Since the patient’s autologous control is negative, an antibody with I
specificity would likely be alloanti-I which may be present in the serum of I negative
individuals.
Case CM: Additional Antibody Identification
Saline Suspended
Selected Red Cells
I negative adult
I negative cord cells
I
II
III
Auto
IS
4+
4+
4+
4+
4+
0
Serum
37oC AHG
4+
4+
4+
4+
4+
4+
4+
4+
4+
4+
0
0
CC
The patient’s serum reacted
equally as strong with I
negative and I positive red
cells.

A Reference Laboratory will be able to perform the testing necessary to evaluate the possibility
of an alloantibody to H or other high-incidence antigens.
Case Study: CM
Patient’s H phenotype: HRed cells which type as group O and are H- are known as Oh or having the “Bombay”
phenotype. These red cells lack normal ABH antigens and the serum contains anti-A, anti-B,
anti-A,B and anti-H. Unlike the anti-H found occasionally in the serum of A1, B and AB
individuals, the Bombay anti-H has a wide thermal range of reactivity and is strongly
incompatible with all red cells except other Oh red cells.
Case Study: CM
Selected Red Cells
Oh
Oh
Oh
Oh
IS
0
0
0
0
Serum
37oC AHG
0
0
0
0
0
0
0
0
CC




In addition to testing the patient’s serum against Oh red cells, the possible presence of additional
antibodies was ruled out by the use of alloadsorptions of the patient’s serum onto red cells of
known antigenic phenotype.
Selected Red
Cells
I
II
III
IS
0
0
0
Case Study CM: Allogeneic Adsorptions
Adsorbed Serum #1
Adsorbed Serum #2
LISS
LISS
37oC
IgG
CC
IS
37oC
IgG
CC
0
0
0
0
0


0
0
0
0
0


0
0
0
0
0


IS
0
0
0
Adsorbed Serum #3
LISS
37oC
IgG
CC
0
0

0
0

0
0

(#1) R1R1 adsorbing cells are s-,Fy(a-), Jk(b-)
(#2) R2R2 adsorbing cells are S-K-Jk(a-)
(#3) rr adsorbing cells are S-K-Fy(b-)
No additional antibodies were detected.
Additional testing which was performed:
 Adsorption onto rabbit erythrocyte stroma reduced the strength of the anti-H but did not
eliminate it.
 DTT (Dithiothreitol) studies showed that although the patient’s anti-H was predominately
IgM in nature, an IgG component was present in CM’s serum. The presence of the IgG
component raised the issue of potential risk to the fetus.
6. In the absence of documented case reports of pregnancies involving Oh individuals with IgG
anti-H, the patient should be evaluated throughout the course of her pregnancy for signs of
possible HDN. The patient should also be evaluated as a candidate for autologous donation
and her siblings tested for the Oh phenotype, in an effort to identify compatible blood donors
should they be needed.