Award Articles and Special Reports
Special Report: Quality Control in Immunohistochemistry
Report of a Workshop Sponsored by the Biological Stain Commission
JULES M. ELIAS, PH.D., ALLEN M. GOWN, M.D., ROBERT M. NAKAMURA, M.D., DAVID C. WILBUR, M.D.,
GILBERT E. HERMAN, PH.D., M.D., ELAINE S. JAFFE, M.D., HECTOR BATTIFORA, M.D.,
AND DAVID J. BRIGATI, M.D.
Although immunohistochemical methods are increasingly applied
in diagnostic histopathology, there has been little standardization
or quality control of immunoreagents; and published reports have
not standardized Material and Methods for meaningful comparisons of results among clinicians. The Biological Stain Commission-sponsored workshop was convened to address the following issues: a manufacturers' testing program for probity of
commercial antibodies, development of a manual for performance
criteria and quality control assurance procedures, standardization
of package inserts, standardization of information provided in
the Materials and Methods sections of publications, establishment of a reagent and procedure clearing house, study of the
effects of different fixation regimes on tissue antigens, and investigation of the environmental conditions needed for antigenantibody interaction. The recommendations of the ad hoc committee and their implications for the future are discussed. (Key
words: Antibodies; Diagnostic histopathology; Immunohistochemical methods; Immunoreagents; Standardization) Am J Clin
Pathol 1989;92:836-843
THE NUMBER OF REPORTS describing the application
of immunohistochemical methods in diagnostic histopathology has grown steadily since the original National
Cancer Institute (NCI)-sponsored workshop on immunoperoxidase techniques in diagnostic pathology held in
May 1979.3 The major concerns of the NCI group were
diagnostic applications for lymphoreticular and endocrine
tumors, oncological developmental markers, and method
considerations.
At the June 1986 annual meeting of the Biological Stain
Commission (BSC), there was a discussion of the need
for quality control of immunostaining reagents and their
technical use that would parallel the successful standardization and certification program of biological stains car-
Received December 30, 1988; received revised manuscript and accepted for publication February 14, 1989.
Address reprint requests to: Biological Stain Commission, Box 626,
University of Rochester Medical Center, Rochester, NY 14642.
University of New York at Stony Brook School of Medicine,
Stony Brook, New York; University of Washington School of
Medicine, Seattle, Washington; Scripps Clinic and Research
Foundation, La Jolla and City of Hope National Medical
Center, Duarte, California; The University of Connecticut
Health Center, Farmington, Connecticut; Sinai Hospital of
Detroit, Detroit, Michigan; National Institutes of Health,
Bethesda, Maryland; and The Milton S. Hershey Medical
Center, Hershey, Pennsylvania
ried out by the Commission in the past 50 years.17 The
pressing need for such quality control was affirmed although the issues and administrative procedures needed
more study. In 1987, the trustees of the BSC accepted a
proposal by one of us (J.M.E.) that a panel of experts be
identified and solicited as to how testing might be done
to obtain quality control in immunohistochemistry and
to identify potential problems involved. As a follow-up,
in June 1988 the BSC supported and convened a one-day
workshop in Washington, D.C., on Standardization of
Immunoreagents. This meeting was attended by an ad
hoc committee.
The BSC workshop was a natural outgrowth of the
original NCI group effort and addressed issues not previously considered or those requiring additional review.
The following topics were discussed for quality control
measures:
1. a voluntary manufacturers' testing program to determine probity of any monoclonal or polyclonal antibody
offered for sale;
2. development of a manual to provide guidelines on
performance criteria and quality control assurance procedures;
3. standardization of package inserts;
4. standardization of information provided in the Materials and Methods portion of published results;
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Vol. 92 • No. 6
5. establishment of a clearinghouse to facilitate the flow
of information;
6. the effects of different fixation regimes on tissue antigens; and
7. investigation of the environmental conditions conducive to antigen-antibody interaction.
The recommendations of the workshop panel were
presented at the annual BSC meeting for consideration
by the Board of Trustees. They have been summarized
in the following report.
Manufacturers' Testing Program
Although this program will be a voluntary one, we expect that the privilege of carrying the commission's "seal
of approval" would be a strong positive incentive for voluntary participation.
All vendors of antibodies will be asked to submit to the
BSC a complete standardized Antibody Specificity Performance Test certification and Product Information
Sheet. The information provided in the Product Information Sheet will be incorporated into the manufacturers'
package insert (see Standardization of Package Inserts).
Antibody Specificity Performance Test
Antibody specificity will be documented by vendor's
certification that the antibody had successfully passed a
"performance test" on a sausage-type block, which will
consist of an array of tissues/tumors fixed in common
fixatives.1"'25 Results of this test will be indicated in terms
of tissue/tumor specificity and optimal fixation requirements.
We discussed several ways of implementing this program. In one, the vendor would be required to supply an
immunostained sausage slide along with the antibody. As
an alternative, vendors could contract with satellite laboratories authorized by our committee and approved by
the BSC and/or the College of American Pathologists
(CAP). These satellites would test the vendor-supplied
antibodies on a sausage-type block. It is possible that, in
lieu of the vendor's actually sending out an immunostained slide, only a copy of the satellite laboratory's report
need accompany the Product Information Sheet.
There was some question as to whether a viable program can be safely left in the hands of the vendors. To
assure credibility, some participants preferred that testing
be done by independent laboratories. A consensus view
on this issue has not been obtained.
Manual
A manual similar to an NCCI guideline will be developed to address performance criteria, quality assurance
837
procedures, technical pitfalls of current methods, and interpretation of results.
Standardization of Package Inserts
Although some manufacturers already provide some
or all of the specific information recommended by the
committee on package inserts for primary antibodies, this
is not standard practice for all primary antibodies. Guidelines are proposed for a uniform approach to reporting
information that will be useful to laboratories using these
reagents. The following are recommended for package
inserts provided with all primary antibody reagents:
1. clone designation for monoclonal antibodies;
2. animal species and preparation techniques for polyclonal antibodies;
3. lot number and specific antibody concentrations;
4. immunoglobulin class;
5. total protein and specific antibody concentrations;
6. antibody diluent or medium where applicable;
7. description of the antigen (immunogen) against which
the antibody was raised;
8. operating characteristics of the antibody, including
reactivities in various fixatives, optimal processing techniques, and use of pretreatment regimes (e.g., proteolytic
enzyme treatment);
9. brief statement of the reactivity of the antibody, with
sensitivity and specificity data for specific tissues or antigen. This section also could identify clinical applications
of the reagent, citing references from the science literature;
10. tissue requirements for positive controls;
11. storage requirements for the antibodies; and
12. shelf life of the antibodies based on storage methods.
In addition to providing a uniform approach to comparison of the results of one laboratory to another, the
inclusion of these data with each antibody sold by commercial manufacturers will greatly assist users to optimize
staining reactions in their own laboratories and would
facilitate interlaboratory comparison of results. Similar
information can be easily transferred to scientific articles
concerning the usefulness, sensitivity, and specificity of a
particular reagent.
Standardization of Material and Methods
Sections in Published Reports
All standard laboratory licensing procedures are based
upon standard methodology (procedure manuals) and
standard checks of control material—both external/internal proficiency testing and accurate documentation.
High quality communication to allow reproducibility of
results is necessary for standardization of diagnosis. Immunohistochemistry, a relatively new technology, lacks
a unified national standard. A review of current literature
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ELIAS ET AL.
from representative pathology and oncology journals reveals significant deficiencies in articles incorporating immunohistochemical techniques.
An example of the current state of immunohistochemistry quality control is illustrated in a recent copy of a
leading pathology journal. An article in this journal is
accepted by many pathologists as established fact; and
based upon this communication, diagnosis on patients
will be rendered. Of the ten articles in this issue, nine
relied on immunohistochemistry to help support the diagnosis and one used only immunohistochemistry to establish a diagnosis not available by other techniques. The
quality control process for the immunohistochemistry
methodology was undertaken to determine if the results
could be easily replicated in other laboratories with only
the information given in the articles.
Because in eight of nine cases the light microscopic
diagnosis was the starting point for case selection, the
questions asked were: "How sure were the investigators
that the light microscopic diagnosis was correct? What
criteria were used to establish the light microscopic diagnosis? What special nonimmunohistochemical tests
served as the gold standard to establish the diagnosis?"
Neuroendocrine peripheral nerve sheath tumors, myospherulosis, giant cell tumor of tendon sheath, signet-ring
carcinoma of prostate, polymorphous adenocarcinoma
of minor salivary gland, Kaposi's sarcoma, hepatic adenoma in glycogen storage disease, and adenocarcinoma
of rete testis were retrieved by the individual investigators
from archival or current case material for point-by-point
case comparison.
After cases were selected in a retrospective manner,
immunohistochemistry was performed, leading to questions about materials and methods, techniques, and protocol. The type of fixative was listed in four papers, with
one paper using "fresh tissue." Four articles stated only
that "paraffin blocks" were used. The specifics of fixation
were not addressed in any article, so time and temperature
were unknown. Only two of four papers stated that 10%
(v/v) neutral buffered formalin was the fixative used.
Tissue processing was not addressed in any paper; thus,
in all likelihood, tissue placed in a vacuum processor using
heat, vacuum, and pressure was treated the same as an
Autotechnicon or hand-processed tissue. The solutions
used, be they ethanol, toluene, xylene, synthetic xylene,
or chloroform, were not mentioned in any paper.
The published immunohistochemical technique was
then examined. Antibody panels, ranging from 3 to 24,
were used in eight of nine papers. Of these, "private" (i.e.,
noncommercially available) antibodies were used in four
papers, and commercial antibodies used in all papers. The
antibodies' lot numbers were not given in any of the papers, whereas the clone numbers were given in three of
A.J.C.P. • December 1989
five monoclonal studies. The antibody titer was given in
only four of nine papers.
In two of nine papers, the initial handling of the immunohistochemistry slides described a blocking step for
endogenous peroxidase, and only one of nine papers described a serum blocking step for nonspecific protein
staining. The actual immunohistochemical staining technique was described in all papers: ABC (four), PAP (six),
indirect (one). Most papers did not state if the techniques
were performed exactly as published by the original investigators or if modifications had been used.
Enzyme pretreatment was done in three of nine papers,
although many articles were studies of paraffin blocks with
antibodies known to require predigestion for maximal activity. When enzyme was used, only two of three papers
indicated the conditions of pretreatment, such as enzyme
concentration, buffer, temperature, and digestion time.
The chromogen was listed in three of nine papers, with
most articles referring the reader to books on immunohistochemistry for "standard methodology" without
mention of specific page numbers for development of the
color reaction.
Regarding quality control procedures, only four of nine
papers indicated a serum control; three of nine mentioned
a ± tissue control. Internal tissue controls were described
in the published Results sections in two of nine papers.
Of interest, normal liver adjacent to an adenoma was reported as negative for alpha-1-antitrypsin, the liver representing the primary organ in which this protein is manufactured.
None of the papers used adsorption or neutralization
antibodies controls; one used radioimmunoassay for determining the antibodies' specificity.
Grading of immunohistochemical reactions was discussed in three of nine papers, with two semiquantitatively
and one quantitatively.
This critical journal review graphically illustrates some
of the problems we face in immunohistochemistry. A recommendation, therefore, will be made to journal editorial
boards that minimum standards be introduced for reporting immunohistochemical data to permit objective
comparisons of potentially conflicting data from different
laboratories.
The Committee will recommend that Materials and
Methods sections of papers include specifics of: fixation
and tissue processing; antibodies' lot numbers, clone
numbers and titrations; enzyme pretreatments and
blocking steps; whether the specific technique is as published by the original investigators or modified (if modified, how?); chromogens; positive and negative controls;
determination of antibody specificity; and grading systems. It would facilitate matters if the recommendations
of the BSC were accepted by the Committee of Medical
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AWARD ARTICLES AND SPECIAL REPORTS
Journal Editors so that uniform technical requirements
peculiar to immunohistochemistry would be automatically implemented by participating journals. 8
Facilitating the Flow of Information
The results of test performances will be disseminated
to the science community through a variety of formats.
Package inserts will include performance standards for an
antibody, and companies also will identify their products
as certified by the BSC through labeling of package containers and commercial advertising.
The Commission or other agency will maintain a list
of tested and approved antibodies, available upon request.
This listing will state performance standards for each antibody evaluated: titrations, diluents, staining protocol
used, tissues tested, and recommended fixatives. All tested
and approved lot numbers also will be listed.
A number of other possibilities exist. A newsletter published by the BSC has been proposed, perhaps in collaboration with a cooperating organization such as CAP, or
inclusion of the same information in the CAP newsletter.
The newsletter also could serve an educational purpose
by publishing brief invited articles on the use of antibodies
in differential diagnosis and by disseminating information
on specific antibodies tested or used in experimental protocols, new techniques, fixation procedures, technique
pitfalls, and other tips of relevance to the clinical pathologist or investigator.
The BSC might maintain a bibliography of publications
relevant to tested antibodies, which could then be distributed to investigators upon request or periodically printed
in appropriate BSC publications such as Stain Technology.
The BSC could distribute, at a reasonable cost, a paraffin sausage-type block containing normal tissues with
appropriate fixation.'"-25 A slide stained in a BSC laboratory would be distributed with the paraffin block. This
slide, stained with a commonly used reagent like antikeratin or antivimentin, would provide a representative
example of well-stained tissue section to serve as a comparison with normal controls prepared for pathologists in
their own laboratories.
Testing laboratories sponsored by the BSC also could
serve as technical advice centers for advice about fixation,
staining procedures, or other methodology questions.
They also could be used as sites for BSC-sponsored continuing medical education programs or workshops for
hands-on instruction in immunohistochemical techniques.
Effects of Tissue Fixation on Immunohistochemistry
The availability of monoclonal antibodies and reliable
kits for immunohistochemistry could theoretically lead
839
to better reproducibility of immunoresults among various
laboratories. It is evident, however, that such is not yet
the case; the literature reveals many examples of discrepancies, even when the same antibodies are used. Variation
in tissue processing is one of the most important factors
of this problem.
Unfortunately, there is no perfect fixative for immunohistochemistry. Some antigens are well preserved with
one but not with another fixative; some are destroyed by
any type of fixation and are available for immunohistochemistry only in frozen tissue. Thus, the safest—although
not the most practical—approach would be to use a variety
of fixatives for every biopsy specimen. The ideal treatment,
covering all bases, would be to snap-freeze an aliquot of
each biopsy sample, fix portions in absolute ethanol or
an alcohol-based fixative such as methacarn, and fix in
buffered formalin. 111 ' 25 Because this is somewhat impractical, and often impossible, in the daily practice of
pathology, it is imperative that a search for a universal
fixative be undertaken.
An ideal fixative should penetrate the tissues rapidly,
preserve most of the antigens, be nontoxic, and result in
conventional histologic preparations that are not much
different from those obtained with formalin fixed tissues.
Formalin
Formalin, the most popular fixative, is unfortunately
not the best suited for immunohistochemical techniques.
It has been hypothesized that formalin and other aldehydes cross-link proteins around antigenic sites, resulting
in a masking effect that interferes with binding of the antibody. This masking can at times be removed by proteolytic enzymes, providing that the antigen itself (or the
epitope, in the case of monoclonal antibodies) is resistant
to the enzyme. To complicate matters further, this crosslinking and the resulting masking effect are gradual and
progressive. Tissues fixed for brief periods (12-24 hours)
may show relatively well-preserved antigenicity. The same
tissues immersed in fixative for longer periods may no
longer be immunoreactive. Because pathologists either do
not pay much attention to the duration of fixation in formalin or have no control over it, this is one of the most
serious drawbacks of formalin fixation and accounts for
much of the lack of reproducibility of immunohistochemistry among laboratories and within the same laboratory.
If formalin fixation is too short (3-6 hours), the tissues
are fixed partially in formalin and partially in alcohol, as
fixation is completed in the automatic processor by the
alcohol baths used in dehydrating the samples. Thus, the
periphery of the specimen may be relatively well fixed
(and cross-linked) in formalin, whereas the core is fixed
840
ELIAS ET AL.
by coagulation by the alcohol. Such tissues are prone to
show a peripheral effect, a phenomenon in which the periphery of the section does not stain or, conversely, is the
only part of the specimen that does stain, depending on
which antigen is sought and by what method.
Although much useful information can be obtained
from formalin-fixed tissues by immunohistochemical
methods, false negative results are commonplace when it
is used. As a minimum recommendation, pathologists
should be urged to fix tissues in buffered formalin and
not to exceed 12, or at most 24, hours of fixation.
B5 and Bouin Fixatives
B5 and Bouin's fixatives often provide better preservation of antigenic molecules than buffered formalin. This
is not always the case, however, because some antigens
can be better demonstrated with formalin fixation. Moreover, they have the disadvantage that prolonged fixation
must be avoided because it often renders the tissue difficult
or impossible to cut. It is conceivable that their apparent
superiority over formalin may be attributable, in great
part, to the fact that their fixation times usually are kept
short.
Alcohol-Based Fixatives
Alcohol-based fixatives include ethanol (95% [v/v] or
absolute), Carnoy's, or methacarn. There is ample evidence from the literature and our own experience that
these coagulating fixatives are superior to formalin and
most other popular fixatives in preserving antigenicity of
tissues. Their distinct advantage over formalin is that a
protease digestion step usually is not needed when immunohistochemistry is performed in tissues fixed in these
noncross-linking reagents.
Ethanol. Tissues may be fixed directly in absolute alcohol, preferably reagent grade. If the sample is kept thin
(3 mm or less), penetration and fixation are relatively fast.
Tissues are then processed directly to clearing agents (xylenes) and embedded in paraffin. Excellent antigen preservation is possible regardless of duration of fixation, and
the tissues are not difficult to section. Its major drawback
is that it introduces shrinkage artifact in excess of that
usually seen with other fixatives.
Carnoy's and Methacarn. These fixatives give similar
results to each other and are comparable to plain ethanol
in antigen survival. They have the advantage over ethanol
in affording faster penetration, so thicker sections can be
used. Also, they do not cause tissues to become brittle as
plain ethanol does.
There are indications that alcohol based proprietary
formulas preserve antigens as well as or better than ab-
A.J.C.P. • December 1989
solute ethanol. 1 '"' 25 Although some tissue shrinkage occurs, it is less than that seen in ethanol-fixed tissues. Morphologic detail approaches that of formalin-fixed tissues.
Its drawback is that tissue enzymes do not appear to be
destroyed by fixation. Prolonged incubation, therefore,
could result in focal tissue autolysis. However, this is not
a problem with the usual shorter incubation periods used
in immunohistochemistry.
In summary, it will evidently be necessary to pay more
attention to tissue handling if reproducibility of immunohistochemical results is to be improved. We must search
for a fixative that can be used instead of formalin for both
routine histologic work and immunohistochemistry. In
view of formalin's known toxicity, such a fixative would
provide additional health benefits.
Microenvironment of the Antigen-Antibody Interaction
The moment of creation in any immunohistochemical
assay is the precise instant that a primary antibody contacts, recognizes, and subsequently unites with the epitopes of its tissue antigen to form the initial immune
complex. All detection systems are simply visualization
tools for this event, the magnitude of which depends entirely on the physicochemical microenvironment in which
the antibody is placed and the state of the antigen at the
tissue surface. In the properly performed immunohistochemical assay, it is the microenvironment of the primary
immune complex that governs the ultimate signal-to-noise
ratio of the immunoassay. Ideally, when the correct
chemical microenvironment is achieved, only specific
unions of the primary antibody and its tissue antigen rapidly form without the occurrence of lower affinity, nonspecific interactions. If the antigen is correctly oriented,
the strength of the reaction should depend on the number
of available epitopes and the corresponding quantity, type,
and variability of immune molecules in the medium.
However, the ingredients in any medium can affect its
performance.
Available evidence indicates that immunoreactivity is
not only affected by the physical effects of heat but also
by the detergent properties, protein concentration, buffer
capacity, trace metals, and animal sera sources of the medium in which a primary immune reaction takes place.
Many immunohistochemistry laboratories use only one
buffer to dilute all their primary antibodies. This buffer
may contain a single carrier protein, but some of these
proteins can block the effect of the primary antibody instead of optimizing its effect. The primary antibody may
contain preservatives to retard bacterial growth that can
also weaken immunoreactivity in storage.
One of the challenges of the future will be to develop
a set of universal standard media that contain the best
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AWARD ARTICLES AND SPECIAL REPORTS
combination of reagents needed by the broadest spectrum
of antibodies for optimal reactivity. The production of
standardized media for primary antibody reactions will
require a systematic study both in the physicochemical
state of the antibody and its antigen to determine if the
immunoreactivity of monoclonal antibodies can be improved by optimizing the availability of their more restricted epitope sites through changes in the type, strength,
and range of the medium used and the mixture of monoclones selected to form an immune cocktail. We will have
to know which media improve the presentation of the
antigen to the microenvironment of the primary antibody,
which systems of enzyme predigestion truly reverse formalin fixation, and which cause the loss of more target
than they are worth. The data should result in a set of
consensus media that generally optimize immunostaining
in an identifiable subset of antigen targets. A comprehensive study to determine the effects of the most widely used
fixatives on tissue antigens could be supported by revenues
generated from charges for evaluating commercial immunoreagents.
Researchers will need a vehicle through which to share
data on the media they have found most effective in improving titer, strength, and specificity of a particular antibody. The formulas for these media can then be universally tested and distributed to industrial production
sites and clinical laboratories to help ensure the uniformity
of an immune reaction. We foresee that the standardization of immunohistochemistry will eventually require international cooperation.
Conclusions
Although immunohistochemistry is a relatively young
science, it already has proved a useful adjunct to conventional morphologic diagnosis.23 However, even its strongest advocates would not hesitate to express concern about
the very real risks associated with interpretation of immunostaining if poorly characterized primary antibody
is used. The proliferation of commercial kits that provide
prediluted antibodies for antigen localization in formaldehyde-fixed, paraffin-embedded human tissue specimens
has fostered a false sense ofsecurity within the community
of users unfamiliar with ramifications of immunologic
reagents that lack defined specificity. Even experienced
immunopathologists can have difficulty with interpretations when they encounter unexpected or anomalous
staining with these reagents.
Anecdotal reports about specificity problems of polyclonal and monoclonal antibodies continue to appear in
the literature.4'6-71012-15'18'21'24 Two of the major contributing factors to this problem are contaminating antibodies
in polyclonal sera and intrinsic cross-reactivity of mono-
841
clonal antibodies. Contaminating antibodies in polyclonal
antiserum may result from impurities in the antigen or
may be present prior to immunization (e.g., autoantibodies or natural antibodies). The disappearance of immunohistochemical staining after preadsorption of the antibody with the antigen does not necessarily validate specificity because the contaminating antibodies may be
adsorbed as well as the specific antibody.22 Only antigens
with proven purity should be used for immunization and
adsorption, but this is not always practical. Preimmune
sera should be tested for the presence of autoantibodies
or natural antibodies.7
The intrinsic cross-reactivity of monoclonal antibodies
due to either shared or common epitopes in either normal
or tumor tissue can not always be anticipated.2 An excellent example is the unexpected cross-reactivity of
monoclonal antibodies due to shared antigenic determinants between hematopoietic cells and components of the
nervous system.5 Although this shared antigenicity is not
generally a disadvantage, it is often not determined until
the antibodies are in use, causing interpretive difficulties.
The use of radioimmunoassay (RIA) to characterize
the specificity of a monoclonal antibody will not reveal
the intrinsic cross-reactivity. Some investigators actually
maintain that RIA specificity testing may not hold any
predictive value for specificity in immunohistochemistry.20'22 The immunohistochemical technique used to examine the distribution of antigens in normal and pathologic human tissues will, in most cases, reveal any peculiar
reactivity of primary antibody regardless of the cause.19
The level of quality control achieved is directly related
to the size and diversity of the sample of normal and
pathologic tissues tested and the experience of the investigator. Users generally have derived specificity information of various markers from studies of nonneoplastic
tissues and of classical and unambiguous tumors, not anaplastic or ambiguous tumors; and the latter were the basis
for many of the published reports that conflict with the
original specificity data. Adequate testing is essential for
learning more about the antigenic phenotype of various
tumors. 14
Because there are no industry-wide standards for assessing antibody specificity, each supplier decides what
constitutes an adequate quality control program for guaranteeing antibody specificity. The kind of extensive testing
required to detect cross-reactivity is beyond the scope of
most manufacturers.9'26 The user is forced either to perform internal quality control or to seek expert assistance.
It is essential that commercial antibodies be subjected to
a rigorous trial under controlled conditions to determine
if they are as reliable as their noncommercial equivalents.
Although the BSC stamp of approval will do much to
alleviate the anxieties of both the consumer and the ven-
842
ELIAS ET AL.
dor, there still will be some unexpected but specific staining in tissues that did not previously express a particular
antigen.1319
A central clearinghouse to oversee the performance
characteristics of a primary antibody will provide all users
with access to the information required to make intelligent
interpretations. The formation of an independent agency,
an "Antibody Staining Committee" of the BSC, supported
by funds from the professional organizations representing
pathologists (e.g., CAP, American Society of Clinical Pathologists, International Academy of Pathologists) is
needed to guarantee that quality control standards are
adequate and uniform so that the purchase of a reliable
commercial antibody is not a problem.16 A trial period is
needed to determine the feasibility and adequacy of the
tactics and logistics for a limited number of selected target
antigens; recall that the testing protocols for additions of
new dyes to the BSC certification list has taken years.
The trend toward commercial kits that provide the disclosing reagents and not the primary antibody is very desirable because the user then has a wider choice of immunologic reagents. However, with this change, the user
assumes more responsibility for the quality (ergo, the
specificity) by choosing one antibody over so many others
with purported similar specificity. Because there are more
than 200 vendors of immunologic reagents, this can be a
formidable, if not impossible, task. Although there are
some suppliers who derive their product from the same
source, that information is presently not available. Clearly,
the BSC committee will not only service the user but afford
the provider with the opportunity for quality control
measures not routinely obtainable in the marketplace. In
particular, the assortment of human tumors and normal
tissue needed for adequate testing coupled with the different fixation regimes needed to determine the optimal
fixative is not achievable by most vendors. Immunologic
reagents whose high quality is.assured by an independent
agency will place the vendor in partnership with the BSC
and afford the buyer the opportunity to select only those
reagents that have been properly evaluated.
In summary, although we tend to assume that tissue
antigen detection with ready-to-use reagents in commercial kits poses no serious problems, the increasing number
of reports describing aberrant or unexpected staining with
these reagents would argue the contrary. It is somewhat
paradoxical that, although manufacturers make bold disclaimers about the use of their reagents for diagnosis because they lack FDA approval, the most prestigious pathology journals publish reports by equally prestigious investigators attesting to the value of immunohistochemistry
in diagnosing human tumors. The development of an
Antibody Staining Committee with all of its ramifications,
A.J.C.P. • December 1989
through its acceptance by suppliers as well as users, can
only hasten the process of FDA approval so desperately
needed in this burgeoning discipline.
Acknowledgments. Other contributors, not in attendance, were: Henry
A. Azar, M.D., Veterans Administration Hospital, Tampa, Florida;
Richard Cartun, Ph.D., Hartford Hospital, Hartford, Connecticut; Robert
A. Erlandson, Ph.D., Sloan Kettering Cancer Center, New York, New
York; Frederick H. Kasten, Ph.D., Louisiana State University Medical
Center, New Orleans, Louisiana; Francis P. Kuhajda, M.D., The Johns
Hopkins Hospital, Baltimore, Maryland; Paul D. Millikin, M.D., Proctor
Community Hospital, Peoria, Illinois; Azordes R. Morales, M.D., University of Miami School of Medicine, Miami, Florida; Juan Rosai, M.D.
and Lawrence D. True, M.D., Yale University, New Haven, Connecticut;
Roger A. Warnke, M.D., Stanford University Medical Center, Stanford,
California; and Theresa L. Whiteside, Ph.D., Pittsburgh Cancer Institute,
Pittsburgh, Pennsylvania.
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2. Dardenne M, Savino W, Bach J-F. Thymomatous epithelial cells
and skeletal muscle share a common epitope denned by a monoclonal antibody. Am J Pathol 1987;126:194-198.
3. De Lellis RA, Sternberger LA, Mann RB, et al. Immunoperoxidase
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10. Kobayashi M, Yanagihana E, Hayashi T. Specificity problem of
polyclonal rabbit antibody. J Clin Pathol 1988;41:705.
11. Kraaz W, Risberg B, Hussein A. Multibock: an aid in diagnostic
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12. Leader M, Collins M, Patel J, et al. Desmin: its value as a marker
of muscle derived tumors using a commercial antibody. Virchow's
Arch [A] 1987;411:345-349.
13. Leader M, Patel J, Collins M, et al. Anti-alpha- 1-antichymotrypsin
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AWARD ARTICLES AND SPECIAL REPORTS
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NEWS AND NOTICES
American Society of Clinical Pathologists/
College ofAmerican Pathologists
Joint Annual Spring Meeting (San Francisco,
CA)
October 20-26, 1990
Joint Annual Fall Meeting (Dallas, TX)
For further information contact: Membership Services, American Society of Clinical Pathologists, 2100 Harrison Street, Chicago, Illinois
60612, or call (312) 738-1336.
For further information contact: Henry A. Wilkinson, M.D., at (704)
355-2251.
March 24-29, 1990
9th Annual Pathology Snowmass Ski Retreat
(Snowmass Conference Center, Snowmass,
CO)
For further information contact: John R. Craig, M.D., St. Jude Hospital, 100 East Valencia Mesa Drive, Fullerton, California 92623, or call
American Registry of Pathology/Armed Forces Institute of Pathology (714)992-3907.
January 22-26, 1990
February 14-15, 1990
February 16-21, 1990
February 24-25, 1990
February 26-March 2,
1990
March 17-18, 1990
Orthopedic Pathology (Bethesda, MD)
Uroradiology (Bethesda, MD)
Genitourinary Pathology (Bethesda, MD)
Neuroradiology Review (Bethesda, MD)
Neuropathology Review (Bethesda, MD)
Hyperbaric Chamber Awareness (Silver
Springs, MD)
March 19-23, 1990
Forensic Dentistry (Bethesda, MD)
Gastrointestinal Pathology Review (Silver
March 18-30, 1990
Springs, MD)
March 31-April 1, 1990 Gastrointestinal Radiology Review (Bethesda,
MD)
For further information contact: American Registry of Pathology,
Room 1062, Armed Forces Institute of Pathology, Washington, DC
20306-6000, or call (202) 576-2980.
February 12-16, 1990
University of Texas Southwestern Medical Center at Dallas
February 9, 1990
Research Advances in Alzheimer's Disease
(National Teleconference)
For satellite down-linking and technical information contact: Julia
Laudenberg, UT Southwestern Medical Center at Dallas, Department
of Gerontology and Geriatric Services, P.O. Box 45567, Dallas, Texas
75245, or call (214) 688-7125.
Hans Popper Hepatopathology Society
March 4, 1990
North Carolina/South Carolina Societies of Pathologists
February 3, 1990
16th Annual William M. Shelley Memorial
Lectureship (Charlotte Memorial Hospital,
Charlotte, NC)
First Scientific Session of the Hans Popper
Hepatopathology Society: Liver Development, Growth and Transformation (Boston
Sheraton, Boston, MA)
For further information contact: Michael A. Gerber, M.D., Department
of Pathology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, Louisiana 70112.