Exeley Inc.

Blancher, Antoine

Øyen, Ragnild

Tossas, Edith

Reid, Marion E.

Roubinet, Frances

Letters to the Editors: A macaque monoclonal antibody anti-CD44: a useful reagent for identifying the dominant type Lu(a&ndash;b&ndash;) phenotype

Garratty, George

In vitro reactions with red blood cells that are not due to blood group antibodies: a review

Sutherland, Janet

The immunoglobulin molecule

Sererat, Thom S.

Veidt, Douglas W.

Arndt, Patricia A.

Warm autoimmune hemolytic anemia associated with an IgM autoanti-Ge

Derr, Diane A.

Dickerson, Stacy J.

Steiner, E.Ann

I M M U N O H E M A T O L O G Y ,  V O L U M E  1 4 ,  N U M B E R  2 ,  1 9 9 872
With the intent to increase laboratory efficiency and according to the
Clinical Laboratory Improvement Act of 1988 (CLIA ’88), a parallel
testing program comparing traditional tube technology with the gel
system technology was undertaken. Test tube indirect antiglobulin
tests were performed using polyethylene glycol (PEG) as the anti-
body enhancement medium. Gel (GEL) column technology used the
ID-Micro Typing System™, using predispensed anti-IgG and low-
ionic-strength saline for antibody enhancement. Tests were per-
formed as described in the manufacturer’s guidelines and the current
edition of the Technical Manual of the American Association of
Blood Banks. Testing included antibody detection, antibody identifi-
cation, direct antiglobulin tests (DATs), antigen phenotyping (K, Fya,
Fyb, S, and s), and elution studies. These procedures were evaluated
for sensitivity, specificity, and efficiency. Sixty-six samples that had
been tested for antibody activity by PEG tube techniques were eval-
uated by GEL. These samples included 49 that were nonreactive and
17 with a positive antibody detection test. Within the latter were 19
antibodies, 17 with specificities considered to be clinically significant
and 2 usually considered clinically insignificant for red cell transfu-
sion. GEL was nonreactive with the 49 PEG negative samples as well
as with the 2 samples containing insignificant antibody. All 17 anti-
bodies of probable clinical significance were detected. Antibody
identification studies were performed on these latter samples, with
GEL results consistent with PEG tube results in all cases. Concordant
results were obtained with 10 of 10 DATs (7 negative, 3 positive), all
77 antigen phenotyping tests (37 negative, 40 positive), and the 6
parallel elution studies (4 negative, 2 positive). GEL testing was
found to be comparable or better when compared with PEG tube
testing in all procedures evaluated. Immunohematology
1998;14:72–74.
Key Words: ID-MTS, PEG-IAT, DAT, GEL
Gel technology is a relatively new system for per-
forming direct and indirect antiglobulin testing.1 The gel
test was introduced in Europe in 19881,2 and has been
used in the United States since 1995.
The gel test uses the principle of controlled centrifu-
gation of red blood cells (RBCs) through a dextranacry-
lamide gel and predispensed reagent in a specifically
designed microtube. Precise volumes of serum or plas-
ma, and/or RBCs are dispensed into the reaction cham-
ber of the microtube. If necessary, the gel card, consist-
ing of six microtubes, is incubated, then centrifuged.
Agglutinated RBCs become trapped in or above the gel.
Unagglutinated RBCs move through the gel and form a
pellet in the bottom of the microtube.
With the intent to increase laboratory efficiency and
according to the requirements of the Clinical Laboratory
Improvement Act of 19883 (CLIA ’88), a parallel testing
program comparing traditional tube technology with gel
technology was undertaken. This study compares stan-
dard tube testing using polyethylene glycol4 (PEG) as an
enhancement medium with results obtained with the
gel (GEL) technology of ID-Micro Typing Systems™
(Ortho Diagnostics Systems Inc., Raritan, NJ).The meth-
ods were evaluated for specificity, sensitivity, and effi-
ciency for the following tests: antibody detection, anti-
body identification, direct antiglobulin tests (DATs),
antigen phenotyping (K, Fya, Fyb, S, and s), and elution
studies.Tests were performed as described in the manu-
facturer’s guidelines and the 11th edition of the
Technical Manual of the American Association of
Blood Banks,5 with some minor modification as noted
in the tests for antigen phenotyping and elution studies.
Materials and Methods
Samples
Serum and EDTA plasma specimens submitted to the
blood bank laboratory for routine pretransfusion testing
were evaluated by the indirect antiglobulin test (IAT).
Samples were tested in parallel by standard PEG tube
tests (PeG®, Gamma Biologicals, Houston, TX), and ID-
Micro Typing System™ gel column with predispensed
anti-IgG (Ortho).
Parallel DATs by each method were performed on
Implementation of gel column
technology, including comparative
testing of Ortho ID-MTS with stan-
dard polyethylene glycol tube tests
D.A. DERR, S.J. DICKERSON,AND E.A. STEINER
ID-MTS versus PEG study
I M M U N O H E M A T O L O G Y ,  V O L U M E  1 4 ,  N U M B E R  2 ,  1 9 9 8 73
RBCs obtained from either EDTA-anticoagulated samples
or cord whole blood samples using both polyspecific
anti-human globulin (AHG) and anti-IgG (Ortho). RBCs
for selected parallel antigen typings (K, Fya, Fyb, S, and s)
were obtained from pretransfusion samples or from
commercially prepared sources.
RBCs for elution studies were collected in EDTA anti-
coagulant and prepared using ELU-KIT II™ (Gamma)
according to the manufacturer’s guidelines.
Standard tube testing
PEG tube tests for antibody detection and identifica-
tion were performed according to the manufacturer’s
guidelines. Specifically, two drops of serum or plasma
and one drop of reagent RBCs were mixed.These were
centrifuged immediately and observed for agglutina-
tion and hemolysis. Two drops of PEG were then
added. Following incubation for 10 minutes at 37°C,
the tubes were again visually inspected for hemolysis,
followed by the IAT using anti-IgG (Ortho) and both
macroscopic and microscopic readings. Negative tests
were controlled by the use of IgG-sensitized RBCs
(Ortho).
DATs were performed with polyspecific AHG, accord-
ing to the manufacturer’s guidelines. Negative tests by
immediate spin were incubated at room temperature for
5 minutes, followed by recentrifugation. Both macro-
scopic and microscopic readings for agglutination were
performed; negative tests were controlled by the use of
IgG-sensitized RBCs. Positive samples were further test-
ed with anti-IgG to differentiate IgG sensitization from
complement sensitization.
Selected antigen phenotyping was performed using
commercially prepared antisera, according to the manu-
facturer’s directions.
Eluates were tested according to the manufacturer’s
package insert, including recommended modifications
to enhance sensitivity for antibody detection whenever
the DAT of the RBCs was weakly reactive (increased
incubation time up to 30 minutes).The final supernatant
was run as a control to ensure adequate washing.Anti-
IgG was used for the IAT.
Gel column method
All tests were performed using ID-MTS Anti-IgG Cards.
Antibody detection, antibody identification, and DATs
were performed according to manufacturer’s instruc-
tions. Antigen typing and eluates were tested according
to the antibody detection procedure, substituting 25µL
of antisera or eluate in place of serum.
Test protocol
Samples were coded prior to testing.The technologist
performing subsequent testing did not know previous
test results. Two technologists performed all tests and
grading of agglutination was standardized for each
method. All results were compared at the antiglobulin
phase.
Results
Antibody detection
Parallel antibody detection was performed on 66 sam-
ples (Table 1). Forty-nine were found to be negative and
16 were positive by both methods.One sample was pos-
itive with tube testing but negative with GEL.
Antibody identification
Antibody identification was performed on all 17 sam-
ples (1 sample contained 3 antibodies), yielding a posi-
tive antibody screen. Seventeen antibodies (2 D, 3 E, c, 4
K, Fya, Jka, Jk:3, S, s, and 2 M) of a specificity and reactiv-
ity suggestive of clinical relevance with respect to the
selection of homologous donor RBC units for transfusion
were reactive in PEG and GEL.Two antibodies (Lea and
N) that are usually considered clinically insignificant
with regard to RBC transfusion were detected with tube
tests but not with GEL. GEL and tube testing displayed
comparable reactivity with antibodies of specificity sug-
gestive of clinical relevance (Table 2).
Direct antiglobulin tests
All three cord blood samples were negative by both
methods (including room-temperature incubated tube
tests), as were four of the EDTA samples.The three posi-
tive samples yielded comparable results with both
polyspecific AHG and anti-IgG: 3+, 1+, and 2+, respec-
tively.When tested by GEL, these samples were 4+, 2+,
and 2+, respectively.
Selected antigen phenotyping
All five commercial antisera (K,Fya,Fyb,S,and s),were
tested in parallel against a full reagent RBC panel and an
Table 1. Results of parallel antibody detection tests
Results PEG GEL
Negative 49 51
Positive: clinically significant* 17 17
Positive: clinically insignificant† 2 0
* Specificities associated with hemolytic transfusion reactions or  decreased
survival of transfused antigen positive RBCs 5
† Specificities not known to be, or only rarely, associated with hemolytic
transfusion reactions or decreased survival of transfused antigen positive
RBCs 5
D.A. DERR ET AL.
I M M U N O H E M A T O L O G Y ,  V O L U M E  1 4 ,  N U M B E R  2 ,  1 9 9 874
antibody detection set. Identical results were obtained
(Table 3).The RBCs of 7 patients, known to be alloim-
munized, were tested by both methods for correspond-
ing antigens (4 K,Fya, S, and s) and found to be negative.
Eluate testing
Eluates were prepared and tested from six positive
DAT samples. Parallel testing was comparable in all stud-
ies. Four samples were nonreactive by each method.
One sample contained antibody of indeterminate speci-
ficity that reacted 3+ with 14 of 14 reagent RBC samples
in GEL and routine tube IAT testing. The final sample,
obtained from a recently transfused patient, yielded anti-
E, reactive 2+ by tube and 4+ in GEL.
Efficiency evaluation
During performance of the parallel testing by two
technologists, other personnel were asked to make a
subjective appraisal of gel technology with respect to
simplicity of testing and increase in productivity.
Although no formal data were determined, all training
participants reported that, in their opinion,gel technolo-
gy yielded a more simplified and efficient test system.
Discussion
When compared with standard tube testing, using
PEG as the antibody enhancement reagent, ID-MTS gel
system technology yielded several benefits:
• Comparable or enhanced sensitivity
• Increased specificity
• Increased efficiency
• Simplified testing procedures
These advantages were noted in all testing situations
evaluated: antibody detection, antibody identification,
DATs, antigen phenotyping, and elution studies.
References
1. Malyska H, Weiland D. The gel test. Lab Med
1994;25:81–5.
2. Lapierre Y, Rigal D,Adam J, et al.The gel test: a new
way to detect red cell antigen-antibody reactions.
Transfusion 1990;30:109–13.
3. Code of Federal Regulations, 42 CFR 493.1213.
Federal Register. 1992;57(40):7164.
4. Nance SJ, Garratty G.A new potentiator of red blood
cell antigen-antibody reactions. Am J Clin Pathol
1987;87:633–5.
5. Walker RH, ed.Technical manual. 11th ed. Bethesda,
MD:American Association of Blood Banks, 1994.
Diane A.Derr, BS, MT(ASCP), Senior Medical
Technologist, Blood Bank Laboratory, St. Francis
Hospital and Health Centers, 1600 Albany Street, Beech
Grove, IN 46107; Stacy J.Dickerson, BS, MT(ASCP),
Blood Bank Laboratory, St. Francis Hospital and
Health Centers, Beech Grove, IN; and E.Ann Steiner, BS,
MT(ASCP)SBB, Field Technical Consultant, Ortho
Diagnostic Systems Inc., Raritan, NJ.
Table 2. Results of parallel antibody identification studies
Specificity PEG GEL
Fya pos* 2–3+†
Jka pos* 1–2+
K 1+‡ 1+
S pos* 2–3+
M 2+ ±-3+
s pos* 3+
D 2+ 2–3+
K 2+ 2–3+
E§ 2+ 2+
c§ 1+ ±–1+
N§ 2+ 0
M 2–3+ 4+
K 2+ 2–3+
E 3+ 3–4+
K 2+ 3+
E 3+ 4+
D mi+¶ ±–2+
Lea 2+ 0
Jk:3 mi+¶ 2+
* Frozen stored samples, graded strength not available
† Reaction strengths graded according to manufacturer’s guidelines
‡ Reaction strengths graded according to previously published guidelines5
§ One sample contained three antibodies
¶ Microscopically positive only
Table 3. Results of parallel selected antigen phenotypings
Antisera RBC antigen status Tube test GEL
K Positive 3* 3
Negative 15 15
Fya Positive 7 7
Negative 8 8
Fyb Positive 10 10
Negative 4 4
S Positive 6 6
Negative 9 9
s Positive 11 11
Negative 4 4
*Number of samples tested for each result
NOTICE TO READERS:
All articles published, including communications and book reviews, reflect the opinions of the authors and do not
necessarily reflect the official policy of the American Red Cross.


Implementation of gel column technology, including comparative testing of Ortho ID-MTS with standard polyethylene glycol tube tests

Beal, Robert

Letters to the Editors: &quot;Those Were the Days&quot;

Ewing, Clinton A.

Rumsey, Dawn H.

Langeberg, Albert F.

Sandler, S. Gerald

Immunoprophylaxis using intravenous Rh immune globulin should be standard practice when selected D-negative patients are transfused with D-positive random donor platelets

Procter, Jo L.

Vique, Faye E.

Alegre, Ed

Honda, Junichi

Matsuo, Kazuhiko

Reid, Diane

Rapid screening of platelet donors for PlA1 (HPA-1a) alloantigen using a solid-phase microplate immunoassay

Issitt, Linda A.

Review and update: blood group terminology

Wise, Scott C.

Larison, Patricia J.

Cook, Lloyd O.

Antibodies to low-incidence antigens and elimination of the antihuman globulin phase of the crossmatch - case report: anti-Wra

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Letters to the Editors: A macaque monoclonal antibody anti-CD44: a useful reagent for identifying the dominant type Lu(a–b–) phenotype