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Critical assessment of four monoclonal antibodies reactive with B-cells in formalin-fixed paraffin-embedded tissues.

Four commercially available monoclonal antibodies, MB1, MB2, LN1 and LN2, were studied to determine their sensitivity and specificity for the diagnosis of B-cell lymphomas when used on formalin-fixed paraffin-embedded tissues. In addition to 125 cases of immunologically characterized non-Hodgkin's lymphoma, a range of normal tissues, reactive lymphoid proliferations, Hodgkin's disease and granulocytic sarcomas were also studied. MB1 was found to give positive results in 53.6% of B-cell lymphomas, but the staining was sometimes weak and patchy; there was also cross-reaction with 1.8% of T-cell lymphomas. MB2 reacted with 88.4% of B-cell lymphomas and the reaction was often strong and diffuse, but it showed cross-reaction with 18.2% of T-cell lymphomas. LN1 and LN2 gave positive staining of 44.9 and 46.4% of B-cell lymphomas respectively, and the results appeared to be inferior to that obtained in B5-fixed tissues; staining was sometimes weak and focal, and they also gave false-positive results in a few cases of T-cell lymphoma. This study shows that MB1, LN1 and LN2 are fairly but not entirely specific for B-cells in the non-Hodgkin's lymphomas, but are not very sensitive when applied to formalin-fixed tissues. MB2 shows a high sensitivity but only moderate specificity. Therefore, when these antibodies are used to determine the immunophenotype of malignant lymphomas, the B-cell nature can be predicted with great confidence only when two, preferably three or more, of the antibodies give positive results. The potential applications of these antibodies are discussed.

Antibodies, Monoclonal↗

The demonstration of plasma cells and other immunoglobulin-containing cells in formalin-fixed, paraffin-embedded tissues using peroxidase-labelled antibody.

A method is described for the demonstration of specific immunoglobulin in plasma cells and other lymphoid cells in sections taken from routine surgical histology specimens which have been formalin fixed and paraffin embedded. An indirect sandwich technique was employed using specific rabbit antihuman immunoglobulin antisera (anti-K, L, G, A, and M) and a swine antirabbit serum Ig G, conjugated with horseradish peroxidase. The presence of plasma cells was revealed by staining the tissue-bound peroxidase-labelled antibody, having previously stained the endogenous peroxidase a contrasting colour. It was possible to demonstrate clearly immunoglobulin in the plasma cells of tissues processed and embedded several years previously. Some of the potential uses of the method are discussed.

Animals↗

Molecular cytogenetic analysis of formalin-fixed, paraffin-embedded solid tumors by comparative genomic hybridization after universal DNA-amplification.

We present a technique which allows the detection and chromosomal localization of DNA sequence copy number changes in solid tumor genomes from frozen sections and paraffin embedded, formalin fixed specimens. Based on comparative genomic hybridization and on universal DNA amplification procedures this technique is possible even if only a few tumor cells are available. We demonstrate the feasibility of this method to visualize complete and partial chromosome gains and losses and gene amplifications in archived solid tumor samples.

Base Sequence↗

Detection of c-Ki-ras oncogene mutation in gastric adenomas with formalin-fixed, paraffin-embedded biopsy materials.

Point mutations at codon 12 of the c-Ki-ras gene were investigated in 103 biopsy tissues from 38 patients with gastric adenoma. DNA from minute specimens of formalin-fixed paraffin-embedded tissue was amplified by nested polymerase chain reaction (PCR) and the restriction fragment length polymorphism (RFLP) method was used to detect mutations of the c-Ki-ras gene. Mutations were detected in 4 of the 38 gastric adenomas (10.5%), but were not detected in intestinal metaplasias and gastric adenocarcinomas. Of the 4 mutation-positive gastric adenomas, the GGT sequence in codon 12 changed to GAT in 2 cases, to GTT in 1 case and to TGT in 1 case. We classified gastric adenomas into three degrees of atypia; mutations were detected only in biopsy tissues with moderate and severe atypia but were not detected in biopsy tissues with mild atypia. When different biopsy tissues from a mutation-positive gastric adenoma were examined, the mutation was not always detected in every tissue sample examined. This suggests that mutations are not homogeneously distributed, even in the same adenoma. It is possible to follow up the mutation of biopsy materials of gastric adenoma by this method.

Adenoma↗

D-14 monoclonal antibody to carcinoembryonic antigen: immunohistochemical analysis of formalin-fixed, paraffin-embedded human colorectal carcinoma, tumors of non-colorectal origin and normal tissues.

The reactivity of D-14 monoclonal antibody (mAb) to a specific epitope of carcinoembryonic antigen (CEA) was evaluated on formalin-fixed, paraffin-embedded tissues. A total of 52 normal tissues, 90 colorectal carcinomas and 127 non-colorectal neoplasms were tested using the peroxidase/antiperoxidase technique. D-14 mAb did not react with normal tissues apart from producing a weak staining of normal colonic glands immediately adjacent to the neoplastic structures. All 61 primary and 29 metastatic colorectal carcinomas expressed the carcinoembryonic antigen. However, there was considerable heterogeneity in cellular antigen expression in both primary and metastatic colorectal carcinomas with 10%-99% of tumor cells staining. Of 22 stomach adenocarcinomas, 14 were also immunoreactive, as were 2 of 5 pancreatic carcinomas. Only 6 of 100 neoplasms of non-gastrointestinal origin expressed weak to moderate immunoreactivity. In 7 cases, colorectal micrometastases not recognized in conventional hematoxylin and eosin slides could be identified with D-14 mAb. The specificity of this antibody could be used in differentiating colorectal carcinomas from other types of tumors, including adenocarcinoma from other sites.

Antibodies, Monoclonal↗

Processing techniques for the demonstration of myelin basic protein in paraffin-embedded optic nerve: an immunoperoxidase study of the developing albino rat.

A comparison was made of the effects of various fixation and processing conditions upon the antigenicity of myelin basic protein (MBP) in sections of paraffin-embedded optic nerve from the developing albino rat as judged by the unlabeled peroxidase-antiperoxidase technique. The fixatives used were: Perfix, 4% and 2% buffered paraformaldehyde (pH 7.4), 10% buffered formalin (pH 7.4); Bouin's, Clark's, and Carnoy's fixatives, and 20% formalin in a solution of HgCl2 that had been saturated at 1 degrees C. Perfix appeared to be the best fixative for the preservation of morphology and MBP antigenicity during the early stages of myelinogenesis but was not satisfactory during the later stages. The buffered aldehydes were slightly more destructive of MBP antigenicity than was Perfix, but they produced satisfactory results following the first postnatal week. Bouin's fixative was similar in effect to the buffered aldehydes, but nonspecific background staining was higher. HgCl2/formalin, Clark's and Carnoy's fixatives were unsuitable. No differences were noted in staining between material processed for embedding using 5, 30, or 60 min schedules.

Acetates↗

Immunohistochemical detection of swine influenza A virus in formalin-fixed and paraffin-embedded tissues.

An avidin-biotin complex (ABC) immunohistochemical method utilizing a commercially-available polyclonal antiserum to human influenza A virus was used to detect antigens of influenza A virus in formalin-fixed, paraffin-embedded tissues of swine. Influenza A antigens were immunohistochemically detected in 28/30 cases in which influenza A virus was demonstrated by virus isolation and in 5/22 cases suspected to be influenza A-infected by clinical and histological criteria, but from which the virus was not isolated. Viral antigen was not demonstrated in 30/30 cases not suspected clinically or histologically to be associated with influenza infection. This method is a convenient, sensitive, and specific means of influenza A virus detection and is applicable to both routine diagnosis of influenza A virus infection and to retrospective and prospective studies of the occurrence and the pathogenesis of this virus in pigs.

Animals↗

Lectin-binding spectra in the hyperplastic human tonsil. Effect of formalin fixation and paraffin embedding on lectin affinity of tissue components.

In order to determine the effect of routine fixation on the lectin affinity of tissue structures, we used unconjugated lectins and an indirect immunoalkaline-phosphatase method for frozen sections, and the peroxidase-anti-peroxidase method for paraffin-embedded, formalin-fixed tissue sections. Fourteen hyperplastic human tonsils were used, and the results of the binding spectra of each lectin were compared. In general, the binding spectrum detected in the paraffin sections was part of the broader range of affinity obtained in the frozen sections. The lectin receptors on the cell surface were especially affected by formalin fixation. On the other hand, the paraffin sections, because of their superior morphology, showed a better localization of the cytoplasmic reaction product and discriminated the cell types more accurately. Thus, the two tissue preparations are rather complementary. In the tonsil peanut agglutinin (PNA) and periodic acid/Concanavalin A (PA/Con A) proved to be suitable tools for distinguishing exactly between the crypt and the surface epithelium. Ulex europaeus agglutinin I (UEA) is a reliable endothelial marker with a strong affinity to the crypt epithelium. In the frozen sections, PNA regularly stained follicular-centre cells on their cell surface. PNA, Helix pomatia agglutinin (HPA), soybean agglutinin (SBA) and Con A stained the histiocytic population, especially PNA which additionally stained an "asteroid" histiocyte. This cell probably corresponds to the antigen-presenting histiocyte of the T-system.

Alkaline Phosphatase↗

Studies on immunoglobulin gene rearrangement in formalin-fixed, paraffin-embedded pathology specimens.

Studies on immunoglobulin gene rearrangement in lymphoid lesions are an increasingly important application of molecular biology in diagnostic medicine. The authors have therefore examined the possibility of detecting such rearrangements in formalin-fixed, paraffin-embedded pathology specimens. Southern blots of DNA obtained from optimally fixed tissues were very similar to blots of unfixed material, except that the electrophoretic mobility of the fixed DNA fragments was sometimes slightly reduced. High-molecular-weight DNA was not recovered from suboptimally fixed partially autolysed samples. Increasing the time of exposure to formalin resulted in loss of hybridizable DNA. Monoclonal rearrangements of heavy and light chain immunoglobulin genes could be detected in formalin-fixed specimens provided that these fixation artifacts were taken into consideration. This technique expands the pool of material available for studies on gene rearrangement and should facilitate the use of such studies in clinical medicine.

Breast Neoplasms↗

Human herpesvirus 8 immunostaining: a sensitive and specific method for diagnosing Kaposi sarcoma in paraffin-embedded sections.

Human herpesvirus 8 (HHV-8) is recognized as a major causal agent of Kaposi sarcoma (KS), and it has been detected in all epidemiologic variants of KS. Until now, detection of HHV-8 in paraffin-embedded sections was done mostly by using reverse transcriptase-polymerase chain reaction. To assess the sensitivity and specificity of an anti-HHV-8 antibody and its potential usefulness for separating KS from its mimickers, we immunostained 72 KS samples and 108 samples of potential mimickers of KS with the monoclonal antibody latent nuclear antigen-1 (LNA-1; Advanced Biotechnologies, Columbia, MD). Cases of KS included all epidemiologic variants of the disease. Non-KS lesions included 34 angiosarcomas, 4 kaposiform hemangioendotheliomas, and 70 various benign vascular lesions. Immunostaining for CD31, CD34, and/or von Willebrand factor (factor VIII) also were performed in all cases. All but 1 case of KS (sensitivity, 99%) and none of the non-KS lesions (specificity, 100%) stained with the LNA-1 anti-HHV-8 antibody. The LNA-1 anti-HHV-8 antibody is a reliable marker of all variants of KS. Because KS mimickers are consistently negative for this marker, its use for diagnostic purposes is recommended.

Adult↗

Monoclonal antibodies (MT1, MT2, MB1, MB2, MB3) reactive with leukocyte subsets in paraffin-embedded tissue sections.

The absence of reactivity on routinely prepared tissue sections has hampered the use of monoclonal antileukocyte antibodies in diagnostic histopathology. Here we describe five new antibodies reactive with leukocyte subsets in formaldehyde-fixed, paraffin-embedded tissue sections. Antibody MT1 is reactive with mature and immature T cells and not with mature B cells. MT2 is reactive with mature T cells and B cells, but not with immature T cells, activated T cells, and germinal center B cells. Antibody MB1 is reactive with all B cells, with about 50% of mature T cells, and not with immature T cells. MB2 is reactive with all B cells and not with T cells. However, MB2 also stains endothelial cells and several types of epithelial cells. MB3 is reactive with B cells and histiocytes, but not with T cells. The antibodies were tested on a series of lymphomas that were also immunophenotyped with a panel of well-established reagents on frozen tissue sections. The results indicate that the MB and MT antibodies are useful tools in the study of reactive and neoplastic disorders of the lymphoid system.

Antibodies, Monoclonal↗

Southwestern histochemistry as a molecular histochemical tool for analysis of expression of transcription factors: application to paraffin-embedded tissue sections.

Southwestern histochemistry is used to localize transcription regulatory factors that bind to specific sequences of DNA and regulate the transcriptional activity of the genes, using a haptenized double-stranded DNA. This method has been developed in fresh frozen sections, but it was difficult to detect a specific signal in paraffin sections. In this review, we focus on the use of Southwestern histochemistry in paraffin sections. To detect a reliable signal in paraffin sections, we autoclaved or microwaved the sample before incubation with probe DNA. As a model system, we assessed estrogen receptor (ER) in paraffin sections of mouse ovary. ER was detected by Southwestern histochemistry in autoclaved or microwaved paraffin sections, and no signal was detected without such pretreatment. The ER staining pattern detected by Southwestern histochemistry was well consistent with that of ER alpha and ER beta detected by immunohistochemistry. Next, we analyzed the expression of cyclic adenosine monophosphate (cAMP)-responsive element binding protein (CREB) in regenerating livers of rats and mice. CREB was detected in hepatocyte nuclei in autoclaved paraffin sections by Southwestern histochemistry. Immunohistochemistry of CREB displayed homogeneous staining in hepatocyte nuclei, while the signal detected by Southwestern histochemistry showed a heterogeneous speckled pattern in the nuclei. CREB expression increased prior to the induction of proliferating cell nuclear antigen (PCNA). Because the PCNA gene has a cAMP-responsive element in its promoter, it can be suggested that CREB may activate the PCNA gene and lead to the induction of hepatocyte DNA synthesis. Our results indicate that autoclave or microwave treatment is very useful for Southwestern histochemistry in paraffin-embedded sections.

Animals↗

Immunocytochemical methods for demonstrating canine distemper virus antigen in aldehyde-fixed paraffin-embedded tissue.

The effects of enzymatic digestion, sodium borohydride reduction, acids used in decalcification procedures and techniques for inactivation of endogenous peroxidase were sequentially evaluated for their effect on the immunoreactivity of canine distemper virus in aldehyde-fixed paraffin-embedded tissue. Enzyme digestion improved immunoreactivity while sodium borohydride reduced background staining. Paraformaldehyde-glutaraldehyde-fixed tissues required thioglycolic acid treatment prior to enzyme digestion and sodium borohydride reduction to obtain results comparable to results obtained in formalin-fixed tissues. Detailed protocols for indirect immunofluorescence and the avidin-biotin-peroxidase complex procedure are provided.

Acids↗

Assessment of mutations of Ha- and Ki-ras oncogenes and the p53 suppressor gene in seven malignant mesothelioma patients exposed to asbestos--PCR-SSCP and sequencing analyses of paraffin-embedded primary tumors.

To examine whether malignant mesothelioma due to asbestos has genetic alterations in the Ha- and Ki-ras oncogenes or in the p53 suppressor gene, we analyzed the point mutations of these genes in paraffin-embedded autopsy samples of the primary tumors of malignant mesothelioma in seven asbestos patients who died from malignant mesothelioma. The genetic analysis was conducted by the polymerase chain reaction-single strand comformation polymorphysms (PCR-SSCP) method in all patients, and through the sequencing of deoxyribonucleic acid (DNA) bases in one patient. No genetic alterations were found in exons 1 or 2 of Ha- and Ki-ras oncogenes, or in exons 5 to 9 of the p53 gene, in any of the patients. Further studies on a larger number of patients are required to reach a definite conclusion concerning the genetic effects of asbestos on malignant mesothelioma.

Aged↗

[Detection of hepatitis C virus RNA in paraffin embedded liver tissues by in situ PCR].

The new technique of in situ polymerase chain reaction (ISPCR) was used to study hepatitis C virus (HCV). ISPCR and in situ hybridization (ISH) were performed to detect HCV in 7 paraffin embedded liver tissues and 8 para-hepatocellular cancer tissues. The positive rates were 6/7 and 4/8 respectively, significantly higher than results obtained by ISH, which were 3/7 and 1/8 respectively. It also demonstrated that the specificity of ISPCR was better than ISH. HCV RNA was not only found in hepatocyte plasma but also in cholangiolar epithelia and monocytes. We conclude that ISPCR is a sensitive and specific method that can improve the accuracy in diagnosis of HCV.

Base Sequence↗

Immunohistochemical evaluation of neoplasms in bone marrow biopsies using monoclonal antibodies reactive in paraffin-embedded tissue.

A panel of commercially available monoclonal antibodies (MoAbs) including LN1, LN2, MB2, L26, Leu M1, UCHL1, MT1 and L60 was used to evaluate a diverse group of neoplastic processes in 256 Zenker's-fixed, decalcified, paraffin-embedded bone marrow biopsies using the ABC immunoperoxidase technique. LN2 and MB2 were useful in delineating the extent of B-cell lymphoproliferative processes and in identifying interstitial patterns of involvement. The combined application of LN2, MB2 and UCHL1 had utility in differentiating B-cell from T-cell lymphoproliferative processes; in no instance was reactivity with LN2 observed in T-cell processes. The combined application of these three MoAbs was also used in differentiating benign reactive lymphoid aggregates from focal malignant B-cell proliferations. LN2 exhibited positivity with the Reed-Sternberg cells (RSC) of Hodgkin's Disease (HD) and significantly aided in the identification of these cells. Staining of RSC with Leu M1 was inconsistent and was observed in only 50% of cases of HD. Use of the entire panel of MoAbs together with more recently available reagents such as Cathepsin G, MAC 387 and neutrophil elastase was essential in optimally evaluating a particular lesion; none of these MoAbs used singly reliably differentiated myeloid from lymphoid, hematopoietic from metastatic, or reactive from malignant processes.

Antibodies, Monoclonal↗

CD30 distribution. Immunohistochemical study on formaldehyde-fixed, paraffin-embedded Hodgkin's and non-Hodgkin's lymphomas.

Two hundred Hodgkin's and non-Hodgkin's lymphomas were immunohistochemically studied for the presence of the CD30 (Ki-1) activation antigen using a monoclonal antibody BerH2 on paraffin-embedded, formaldehyde-fixed tissue. Immunohistochemistry was performed by using the avidin-biotin complex technique and was preceded by enzymatic digestion with pepsin (0.05% for 20 minutes). Ninety percent (56/64) of cases of Hodgkin's disease, other than lymphocyte predominance type, showed positive tumor cells, although the positivity was often focal. In contrast, lymphocyte predominance type showed CD30 in only two of nine cases. CD30 was commonly seen in non-Hodgkin's lymphomas. Five of 37 large-cell lymphomas showed extensive CD30 positivity and morphologically represented large-cell anaplastic lymphomas ("Ki-1 lymphomas"). Apart from this, occasional CD30-positive cells were seen in nine of 32 large-cell non-Hodgkin's lymphomas. About half of the nodular small cleaved-cell lymphomas contained CD30-positive cells, two of them showing large numbers of positive cells both within and outside the nodules. Lymphocytic lymphoma sometimes (6/17) showed a few CD30-positive cells. Peripheral T-cell lymphomas showed positive cells in three of eight cases. The positive cases were one lymphoma with small groups of epithelioid cells (Lennert's lymphoma) and two immunoblastic lymphadenopathylike peripheral T-cell lymphomas. The results show that CD30 is more widespread than originally thought in non-Hodgkin's lymphomas and that especially nodular small cleaved-cell lymphomas often contain positive cells. These findings have to be considered in the immunohistochemical differential diagnosis of lymphomas. Obviously, CD30 alone cannot be used to differentiate between Hodgkin's and non-Hodgkin's lymphomas. The CD30-positive cells in non-Hodgkin's lymphoma may represent a link between Hodgkin's and non-Hodgkin's lymphomas.

Antibodies, Monoclonal↗

Coxsackie B antigen in the central nervous system of a patient with fatal acute encephalitis: immunohistochemical studies of formalin-fixed paraffin-embedded tissue.

A case of fatal acute encephalitis due to Coxsackie B1 virus is described. Confirmation of Coxsackie B virus as the etiological agent of encephalitis was based on identification of the virus antigen in formalin-fixed paraffin-embedded tissue sections. In the past, the diagnosis was obtained by serological studies of peripheral blood and viral isolation. This is the first report in which indirect immunofluorescent and immunoperoxidase methods using rabbit antiserum raised against Coxsackie B types 1-6 was utilized in determining the etiology of encephalitis. It must be emphasized that these methods can be used both on biopsy or autopsy specimens, even retrospectively.

Antigens, Viral↗