Search

Aims: The cellular response to hypoxia includes the hypoxia inducible factor (HIF)-induced transcription of genes involved in diverse processes such as glycolysis, angiogenesis and the growth of experimental tumours. Regulation of the level of hypoxia inducible factors 1alpha and 2alpha (HIF-1alpha and HIF-2alpha) is a primary determinant of HIF activity. Recent biochemical and candidate gene approach studies have led to the discovery of three HIF-regulatory prolyl hydroxylases, PHD-1, -2 and -3 and an asparaginyl hydroxylase, also known as FIH (factor inhibiting HIF). In this study, we raised and characterized monoclonal antibodies against PHD-1, PHD-2, PHD-3 and FIH., Methods and Results: Immunohistochemistry of normal tissues with these monoclonal antibodies demonstrated a wide distribution in epithelial cells, stromal cells and leucocytes, with cytoplasmic staining predominating over nuclear staining. A preliminary study of tumours showed variable staining in tumour, stromal and inflammatory cells. While all tumour types showed some positive staining with each antibody, the overall pattern suggested a slight decrease in the amount of staining seen with PHD-1, -2 and -3 and an increase in FIH staining in neoplasia compared with corresponding normal tissues., Conclusions: These monoclonal antibodies will allow further larger scale studies to determine the significance of PHD and FIH expression in neoplasia.

Aims: Angiogenesis is an important factor in tumour growth and metastasis. Vascular endothelial growth factor receptor 2 (VEGFR-2) or KDR plays a crucial role in angiogenesis. The aim of this study was to raise and characterize antibodies against phosphorylated KDR which could be used for studies on human tissues to assess KDR activation and novel inhibitors of KDR activation in clinical trials., Methods and Results: Three monoclonal antibodies and one rabbit polyclonal antiserum were produced. The specificity of the antibodies was confirmed by ELISA. One of the mouse antibodies and the rabbit polyclonal antiserum reacted with a 200-kDa band on a Western blot of human umbilical vein endothelial cell (HUVEC) lysates, the molecular weight of KDR. Immunohistochemical staining showed that phosphorylated KDR is present in a wide variety of normal tissues including liver, colon and placenta, and is not restricted to endothelium. It was also present in a number of human tumours including breast carcinomas, colonic carcinomas and non-Hodgkin's lymphomas. The pattern of staining was membranous, cytoplasmic and nuclear., Conclusions: This study has shown that phosphorylated KDR is present in a wide variety of tumour and tissue types and is not confined to endothelium.

LH39, is a monoclonal antibody recognizing an epitope located at the lamina lucida of mature small veins and capillaries but not in newly- formed vessels of several pathological conditions including cancer. We examined the ratio of mature/immature vessels in 50 breast and 81 lung carcinomas and correlated the vascular maturation index (VMI) to different clinicopathological variables including angiogenesis. Mature vessels were defined by staining with antibodies to both LH39 and CD31, using double immunohistochemistry, whereas immature vessels stained only for CD31. VMI was defined as the percentage fraction of mature vessels (LH39 positive)/total number of vessels (CD31 positive). VMI in breast carcinomas ranged from 0-47% (median 8.75%), which was significantly lower than that observed in the normal breast cases (range 54%-70%; median 68%). The median VMI in the non-small cell lung carcinomas was 46% (range 15%-90%). There was a significant inverse correlation between high tumor VMI and absence of nodal involvement in both breast and lung tumors examined (p=0.01). Thymidine phosphorylase (TP) expression, but not vascular endothelial growth factor (VEGF) expression, was related to a low VMI showing an intense vascular remodeling in TP expressing cases. Thus, assessment of vessel maturation might be complementary to microvessel number to aid the identification of patients who might benefit from specific antiangiogenic therapies or vascular targeting treatment.

The aim of this study was to raise and characterize a monoclonal antibody reactive with VEGF (vascular endothelial growth factor) in routinely fixed specimens and to use it to investigate its tissue distribution in normal and pathological specimens. Recombinant VEGF 189 protein was used to raise a monoclonal antibody. The specificity of the antibody was confirmed using COS cells transfected with cDNA coding for VEGF 121, 165 and 189 protein and by western blotting studies. The resulting antibody VG1 was shown to react with the 121, 165 and 189 isoforms of VEGF protein in routinely processed material. In normal tissues, there was strong staining of endometrial and salivary glands and of the mucosa of the gastro-intestinal tract. In tumours, a proportion of the neoplastic cells in lung and breast cancer and in melanoma were labelled. In all tissues, whether normal or malignant, striking VEGF positivity was seen in plasma in vessels and stroma. This study has shown that antibody VG1 detects the 121, 165 and 189 VEGF isoforms in routinely fixed specimens. The results of the normal tissue and tumour labelling are in agreement with other studies using alternative methods of detection. This should be a useful and reliable reagent for studies of VEGF and angiogenesis in human pathological material.

Transient transfection of COS-1 cells followed by fixation, embedding in paraffin, and immunohistochemistry has identified anti-vascular endothelial growth factor (anti-VEGF) mouse monoclonal antibodies that efficiently immunostain VEGF in paraffin-embedded tissue sections. Immunohistochemical localization of VEGF in 34 specimens of normal human endometrium that had been collected at different stages of the menstrual cycle was then performed. VEGF was present at all stages of the cycle, but both the pattern and the intensity of staining varied. Thus, VEGF expression occurred predominantly in the endometrial epithelium and while weak in the proliferative phase, was strong in the secretory phase. VEGF expression in the stroma was weaker than in the proliferative phase glands and did not change throughout the cycle. These findings are in agreement with reports of VEGF mRNA expression in the endometrium, but disagree with previous immunohistochemical studies that employed an immunohistochemically unvalidated antiserum. This study has shown that the commercially available anti-VEGF monoclonal antibody M293 is excellent for the immunohistochemical localization of VEGF in paraffin sections.

The reproductive cycle in eukaryotic cells is partly controlled by the p34 protein kinase, the product of the cdc2 gene. We report here the tissue reactivity of four new anti-cdc2 monoclonal antibodies in relation to the known proliferation markers Ki-67 and JC1. In tissues where proliferation occurs, germinal centres in the tonsil, basal layers of tonsular epithelium and skin, cortex of the thymus, seminiferous tubules of the testis and epithelium of the colon, the anti-cdc2 antibodies gave positive nuclear staining as did the proliferation markers. The percentage of positive cells was, however, lower with the cdc2 antibodies. Given the role of the cdc2 gene at specific points of the cell cycle, these antibodies are potentially useful as markers of different phases of the cell cycle and may help to detect abnormalities in cell cycle control in disease.

Aim: To characterise a newly developed mouse monoclonal antibody JC1 which recognises a nuclear antigen present in proliferating cells in normal tissues and neoplastic lesions, and which is absent in resting cells., Methods: The methodology was established using a representative range of frozen sections from normal tissues and from certain tumours which were immunostained with antibodies Ki67 and JC1. The molecular weight of the antigen recognised by JC1 was obtained by western blot analysis and this was compared with that of Ki67. IM-9 cell lysates containing Ki67 derived plasmids were also tested with JC1 antibody., Results: Biochemical investigation indicated that the antigen recognised by JC1 gives two molecular weight bands of 212 and 123 kilodaltons, which is distinct from the well characterised anti-proliferation monoclonal antibody Ki67 (395-345 kilodaltons). In addition recombinant Ki67 protein is not recognised by JC1. Immunohistological reactivity was seen in areas known to contain numerous proliferating cells such as lymphoid germinal centres, splenic white matter, cortical thymocytes and undifferentiated spermatogonia. In tumours many cells from adenocarcinomas, oat cell carcinomas, squamous cell carcinomas of lung, and seminomas were labelled by JC1 with a distribution and proportion similar to that seen with Ki67. In normal tissues the only apparent difference was in testis where JC1 stained a considerably greater number of cells than Ki67. In all cases studied the new antibody showed nuclear reactivity only. JC1 did not show any cytoplasmic crossreactivity with squamous cells as is frequently seen with Ki67., Conclusion: Antibody JC1, which recognises a nuclear antigen present in proliferating cells, should provide a useful adjunct to Ki67 as a marker of proliferation especially in those cases such as squamous cell carcinomas where a Ki67 index cannot be determined.

mAbs have been raised against different epitopes on the protein product of the DMDL gene, which is an autosomal homologue of the X-linked DMD gene for dystrophin. These antibodies provide direct evidence that DMDL protein is localized near acetylcholine receptors at neuromuscular junctions in normal and mdx mouse intercostal muscle. The primary location in tissues other than skeletal muscle is smooth muscle, especially in the vascular system, which may account for the wide tissue distribution previously demonstrated by Western blotting. The DMDL protein was undetectable in the nonjunctional sarcolemma of normal human muscle, but was observed in nonjunctional sarcolemma of Duchenne muscular dystrophy patients, where dystrophin itself is absent or greatly reduced. The expression of DMDL protein is not restricted to smooth and skeletal muscle, however, since relatively large amounts are present in transformed brain cell lines of both glial and Schwann cell origin. This contrasts with the low levels of DMDL protein in adult brain tissue.

A new monoclonal antibody NB84 recognizing an uncharacterized molecule of 57 kD was produced using human neuroblastoma tumour tissue as a source of antigen. The antibody was selected for its ability to give reliable staining on conventional formalin-fixed, paraffin-embedded material. In the present study, NB84 was assessed for its usefulness in the differential diagnosis of paediatric small cell tumours. It gave reliable staining of 17/19 (90 per cent) neuroblastomas and was negative on all other tumours apart from Ewing's sarcomas, of which 9/14 (64 per cent) showed mainly focal positivity. It is concluded that in association with a panel of markers against leucocyte, muscle, epithelial, and neural markers NB84 provides considerable assistance in the recognition of neuroblastoma and thus is important in enabling the most appropriate therapy to be given.

A new monoclonal antibody, JC70, raised against a membrane preparation from a spleen affected by hairy cell leukaemia, recognises a membrane bound glycoprotein identical with that of the CD31 group of monoclonal antibodies. The antibody stains a fixation resistant epitope on endothelial cells in benign and malignant conditions in a wide variety of paraffin wax embedded tissue. JC70 stained malignant endothelial cells in 10 angiosarcomas with more consistency than monoclonal or polyclonal antibodies to factor VIII related antigen (FVIII-Rag). In four cases of Kaposi's sarcoma the antibody stained malignant endothelial cells but not spindle cells. It is concluded that antibody JC70 is of value for studying benign and malignant human vascular disorders in routinely processed tissue.

A panel of monoclonal antibodies reactive with normal human lymphoid cells and with hairy cells has been applied to the immunocytochemical analysis of hairy cell leukemia. Staining was performed by immunoenzymatic methods on frozen sections of bone marrow trephines and extramedullary tissues and on cell smears. Hairy cells reacted with antibodies against HLA-DR, leukocyte common antigen, B-cell antigens (antibodies To15 and B1) and with three anti-hairy cell monoclonal antibodies (S-HCL3, HC1, and HC2). Neoplastic cells in other B-cell lymphoproliferative disorders also expressed HLA-DR, leukocyte common, and B-cell antigens but were consistently negative for the antigen detected by monoclonal antibody S-HCL3. Furthermore, hairy cells differed from other neoplastic B-cells in that they were unreactive with monoclonal antibodies against C3b receptors, anti-Leu-1, Tü1, Tü33, and lacked a meshwork of dendritic reticulum cells. These findings establish a distinctive antigenic phenotype for hairy cell leukemia and indicate that it may be diagnosed reliably by immunoenzymatic labeling of tissue sections or cell smears.

A new monoclonal antibody, KP1, against the CD68 antigen, which labels macrophages and other members of the mononuclear phagocyte lineage in routinely processed tissue sections, has been used to stain a range of lymphoid, histiocytic, and myelomonocytic proliferations. All 20 neoplasms of myeloid, myelomonocytic, and presumed macrophage derivation reacted with antibody KP1. None of the 22 cases of T cell neoplasia had positive reactions. Although 14 of 41 B lineage lymphomas and leukaemias were stained by antibody KP1, staining was usually confined to small dots of reactivity, in contrast to the strong and extensive cytoplasmic staining seen in the neoplasms of myeloid and macrophage/monocyte origin. Furthermore, positive B cell neoplasms were almost all small cell proliferations, which are unlikely to be confused with myelomonocytic malignancies. It was concluded that antibody KP1 is a valuable addition to a panel of monoclonal antibodies for phenotyping lymphomas, particularly in routinely fixed tissues. It should assist the pathologist in the recognition of extramedullary presentation of leukaemia, aid in the diagnosis of suspected cases of true histiocytic neoplasia, and allow for quantitation of macrophages infiltrating lymphomas and other solid tumors.

It has been reported that the monoclonal antibody BE2, raised against leukaemic T cells, reacts specifically with malignant lymphoid cells and represents a valuable reagent for the early identification of cutaneous T-cell lymphomas. To test this hypothesis, a comprehensive range of nodal and cutaneous biopsies have been examined immunohistologically using single and double immunoenzymatic and immunofluorescent staining methods. BE2 showed a broad range of reactivity, consistently labelling normal endothelial cells, B-lymphocytes in mantle and marginal zones, T-lymphocytes in the paracortex of lymph nodes and medulla of thymus, as well as a variety of different macrophage types, including Langerhans cells and dermal macrophages. Furthermore, although BE2-positive T-lymphocytes were most frequent in malignant lymphomas, they were also found in four of 19 benign dermatoses. We conclude that BE2 is neither T-cell nor tumour-cell specific, and that use of this reagent on tissue sections is unlikely to improve the diagnosis of cutaneous lymphomas.

An immunoelectron microscopic technique was used to analyse the distribution in term human placentae at the ultrastructural level of three antigens recognized by recently developed monoclonal antibodies. Two of the antigens (recognized by NDOG-1 and NDOG-2) were present only on the outer villous membrane of the syncytiotrophoblast. The other (HLA-A, B, C) was absent from syncytiotrophoblast and present on some capillary endothelial cells and on Hofbauer cells in the villous stroma.

The present paper describes a new monoclonal antibody (KB61) raised against hairy cell leukaemia cells. Antibody KB61 recognizes a molecule of approximately 40,000 molecular weight on human B cells. It reacts with B lymphocytes in the peripheral blood, in primary lymphoid follicles, in the mantle zone of secondary follicles, in interfollicular areas and in splenic marginal zone areas. However, germinal centre lymphoid cells do not express the antigen recognized by antibody KB61. The antibody shows limited reactivity outside the lymphoid system, i.e. polymorphs, tissue macrophages endothelial cells in the hepatic sinusoids. Antibody KB61 discriminates between different types of B-cell malignancies, reacting with the neoplastic cells in hairy cell leukaemia, chronic lymphocytic leukaemia (of B-cell type), prolymphocytic leukaemia and centrocytic lymphoma, but not with acute lymphoblastic leukaemia, germinal centre-derived lymphomas (other than centrocytic), Burkitt's lymphoma and lymphoblastic lymphoma. Antibody KB61 may be of value in the study of B-cell subpopulations and in the differential diagnosis of B-cell neoplasms.

Conventional fixation and paraffin embedding of human tissue destroys most of the antigens detected with currently available antibodies, while cryostat sections give poor morphological detail and require freezer space for storage. However, when tissue was freeze-dried before being embedded in paraffin S then stained for a wide range of antigens recognised by monoclonal antibodies (including T-cell and B-cell antigens), morphological preservation was clearly better, and the labelling reactions were of equal (or greater) intensity, than with cryostat sections. As the number of diagnostically important monoclonal antibodies continues to increase the use of freeze-dried paraffin sections should facilitate the introduction of immunohistological techniques for both routine histopathological diagnostic work and immunological research.

This paper describes the use of a panel of seven monoclonal antibodies (selected so as to include reagents reactive with both epithelial and lymphoid cells) for distinguishing between anaplastic carcinoma and high grade lymphoma. Details are given of the immunohistological reactions of these antibodies against a wide range of both normal and malignant tissues and of a number of practical instances in which use of the antibody panel enabled a diagnosis to be made when routine histological examination had been inconclusive.

Two monoclonal antibodies (To15 and 4KB128) specific for the B cell-associated CD22 antigen (135,000 mol wt) are described. On immunoenzymatic analysis of cryostat tissue sections, these antibodies strongly label both mantle zone and germinal center B lymphoid cells in secondary lymphoid follicles (and also scattered extrafollicular lymphoid cells) but are unreactive with other cell types (with the exception of weak reactivity with some epithelioid histiocytes). These reactions differ from those of monoclonal antibodies B1 and B2 (anti-CD20 and CD21) but are similar to those of the pan-B antibody B4 (anti-CD19). One of the anti-CD22 antibodies (To15) has been tested extensively by immunoenzymatic labeling on greater than 350 neoplastic lymphoid and hematological samples. The CD22 antigen was found in tissue sections in most B cell-derived neoplasms, the major exceptions being myeloma (all cases negative) and a small proportion of high-grade lymphoma (6% of cases negative). In cell smears, the antigen could be found on neoplastic cells in most B cell lymphoproliferative disorders, including common acute lymphoblastic leukemia (ALL) (90% positive) and B cell chronic lymphocytic leukemia (CLL) (89% positive). We conclude that anti-CD22 antibodies are of value for identification of human B cell lymphoproliferative disorders (especially when used in conjunction with anti-CD19 antibodies). Previous reports that the CD22 antigen is absent from many B cell neoplasms are probably due to its being expressed within the cytoplasm of immature B cells rather than on their surface.

The prognostic value of immunophenotyping lymphomas was assessed by studying 51 cases of high-grade non-Hodgkin's lymphoma for which long term clinical follow-up (14-28 years) was available. Using antibodies which identify T- and B-cell-related antigens in formalin-fixed, paraffin-embedded material, 43 were shown to be of B-cell and eight of T-cell phenotype. In terms of survival, cases of high-grade T-cell lymphoma fared significantly worse (P less than 0.05) than cases of high-grade B-cell subtype. These findings support the belief that T-cell lymphomas have a more aggressive clinical course than their B-cell counterparts.

A newly developed monoclonal antibody (Y1/82A), which binds a cytoplasmic antigen in peripheral blood monocytes and tissue macrophages, was tested for its ability to detect monocytic differentiation in acute myeloid leukemia, i.e., to distinguish French-American-British (FAB) groups M4 and M5 from FAB groups M1, M2, M3, M6 and M7. Staining was performed by the alkaline phosphatase-antialkaline phosphatase (APAAP) immunocytochemical technic on bone marrow smears from 29 cases of acute myeloid leukemia, on 17 normal peripheral blood and/or bone marrow smears, on bone marrows from 10 cases of lymphoid leukemia, and on lymph nodes of 13 patients with lymphoma. Neoplastic cells from 11 of 11 patients with either M4 or M5 leukemia had positive results, whereas only 2 out of 18 cases of M1, M2, M3, M6, and M7 leukemia had positive results. In normal samples, only peripheral blood monocytes, bone marrow macrophages, and megakaryocytes stained. Lymphoid neoplasms were unreactive. These results suggest that monoclonal antibody Y1/82A may be a useful reagent in detecting cases of M4 and M5 acute myeloid leukemia and that it offers a valuable alternative to nonspecific esterase cytochemistry.

A new monoclonal antibody, Y1/82A, was raised against phytohaemagglutinin activated peripheral blood mononuclear cells. Using an immunohistochemical technique it was shown that Y1/82A reacts against peripheral blood and bone marrow monocytes and resident macrophages from essentially all human tissues. Y1/82A bound to determinants present in leukaemic cells from patients with acute myelomonocytic leukaemia and acute monocytic leukaemia, but not to neoplastic cells from patients with malignant lymphoproliferative disorders or malignant epithelial tumours. Y1/82A failed to react with other cell types, with the exception of osteoclasts and megakaryocytes. Analysis by Western blotting showed that the antigen detected by antibody Y1/82A was associated with intracellular granules in macrophages. Monoclonal antibody Y1/82A may be useful in the diagnosis of monocytic leukaemias and histiocytic neoplasms and in the identification of macrophages in tissues from various inflammatory and neoplastic conditions.

The production and characterization of a new monoclonal antibody, Y2/51, against platelet glycoprotein IIIa is described. A useful feature of this antibody is its ability to recognize platelets and megakaryocytes in formalin-fixed routinely processed material. It could also be used to reveal platelets both in thrombi in large vessels and in microthrombi too small to be readily apparent on conventional microscopic examination. For this purpose it was helpful to use the antibody in conjunction with a new monoclonal reagent (Ret40f) against red cell sialoglycoprotein beta which detects red cells and their precursors in routinely processed tissue. The use of these antibodies should be valuable for the detection of thrombi in a variety of situations such as renal transplant rejection, coronary artery disease and vasculitis.

A monoclonal antibody, NP57, was produced and used against the neutrophil granule protein elastase, which selectively stain neutrophils in cryostat and paraffin wax sections. The antibody stains neutrophils and a subpopulation of monocytes in blood smears and neutrophil precursors in bone marrow smears, and gives positive reactions with the cell lines HL60 and U-937. It labelled the blast cells in 68% of cases of acute myeloid leukaemia (M1-M5) but was unreactive with all cases of lymphoid leukaemias. Most of the elastase negative myeloid leukaemias were labelled by monoclonal anti-myeloperoxidase (antibody MPO-7) as were cells from the promyelocytic line HL60. No cases of myeloid leukaemia showed the opposite pattern--that is elastase positive, myeloperoxidase negative, suggesting that the production of myeloperoxidase precedes the onset of elastase synthesis during myeloid maturation. The anti-elastase antibody NP57 is a useful addition to the range of monoclonal antibodies available for the differential diagnosis of acute leukaemia by alkaline phosphatase-antialkaline phosphatase (APAAP) labelling of cell smears; it may also be of value for the histopathological diagnosis of tumour deposits in myeloid leukaemia and for the detection of neutrophils in paraffin sections.

Two monoclonal murine antibodies have been raised against a delipidated extract of human cream. These antibodies were detected by immunohistological screening of hybridoma culture supernatants on sections of human breast tissue. One of those antibodies (E29) was subsequently screened against a range of normal and neoplastic human tissues and shown to react with a wide variety of human epithelia and with mesothelial cells. Antibody E29 was unreactive with other cell types, with the exception of occasional plasma cells. Antibody E29 is suitable for use on paraffin embedded tissue and represents a valuable reagent for the identification of tumours of epithelial origin.

This paper describes the use of a recently developed immuno-alkaline phosphatase method (the 'APAAP' technique) for labelling frozen sections of undecalcified bone marrow biopsies with monoclonal antibodies, including reagents reactive with T cells and their subsets, B cells, glycophorin, HLA-DR antigen, common ALL antigen, epithelial cells and megakaryocytes. Use of an immuno-alkaline phosphatase technique avoids problems due to endogenous enzyme activity encountered when staining bone marrow by immunoperoxidase procedures. Immunohistological labelling of frozen trephine biopsies is of particular value when it is impossible to aspirate marrow particles and for identifying cells which do not readily enter suspension (e.g. dendritic reticulum cells or stromal cells). Details are given of cases in which immunohistological analysis was used for the phenotyping of acute leukaemias, for the differential diagnosis of intramedullary T and B cell proliferations, and for identifying bone marrow metastases.

The immunoreactivity of six different monoclonal antigranulocyte antibodies (Leu M1, TG1, 3C4, BY/87a, BY/37a, and 3CD1) has been evaluated in 23 cases of Hodgkin's disease (7 lymphocyte predominant, 12 nodular sclerosing, and 5 mixed cellularity); in a variety of non-Hodgkin's lymphomas and in a series of reactive and benign lesions of lymph nodes. Applying a monoclonal antibody (PD7/26) to leukocyte common antigen (T200), we have also investigated reports that the L&H variants in nodular lymphocyte predominant Hodgkin's disease are strongly immunoreactive for leukocyte common antigen in contrast to the lack of reactivity of Reed-Sternberg (RS) cells and variants thereof in other forms of Hodgkin's disease. All six monoclonal anti-granulocyte antibodies reacted against RS cells and "Hodgkin's cells" in the nodular sclerosing (NSHD) and mixed cellularity (MCHD) types, with strong cell membrane and juxtanuclear (Golgi) staining. In contrast an anti-leukocyte antibody PD7/26 was unreactive with RS cells and variants thereof in NSHD and MCHD. On the other hand, RS cells and L&H variants thereof in the nodular L&H form of Hodgkin's disease (nodular lymphocyte predominant type) showed reactivity with PD7/26 but not with the anti-granulocyte markers. Rare L&H cells in 2 cases of diffuse lymphocyte predominant type showed reactivity with some, but not all, of the anti-granulocyte antibodies. These findings provide further support for the concept that the nodular L&H type of Hodgkin's disease represents an entity distinct from other forms of this disorder. Our studies also demonstrate the usefulness of these immunoperoxidase techniques when applied to formalinfixed, paraffin-embedded tissues.

The use of monoclonal and polyclonal antibodies for the immunophenotyping of non-Hodgkin's lymphomas in paraffin-embedded tissue has been limited by the fact that most antigens on lymphoid cells are denatured by histologic fixation, dehydration, and embedment. In this article the authors have analyzed a small panel of antibodies which represent exceptions to this rule, in that they identify denaturation-resistant determinants on leukocyte antigens in paraffin-embedded tissue. Monoclonal antibodies L26 [corrected] and 4KB5 label preferentially B cells, monoclonal antibody UCHL1 stains predominantly T cells, and monoclonal antibody MAC 387 reacts with granulocytes and some macrophages. A polyclonal antiserum raised against purified CD3 (T3) antigen, a T-cell-specific molecule, was also employed. This antibody panel was used to immunophenotype routinely processed tissue biopsy specimens from 61 non-Hodgkin's lymphomas (all of which had been previously phenotyped in cryostat sections). The lineage of the neoplastic cells was correctly identified in 32 of 34 (94%) cases of B-cell lymphoma, in 19 of 19 (100%) cases of T-cell neoplasm, and in 2 of 4 (50%) cases of histiocytic malignancy. It is concluded that this combination of antibodies is helpful in immunophenotyping non-Hodgkin's lymphomas when only paraffin-embedded tissue sections are available, although additional reagents of higher specificity are required to improve the identification of lymphomas.

Cryostat sections of skin biopsies from 83 patients with benign or malignant cutaneous lymphoid infiltrates were examined immunohistologically for reactivity with Ki-67 (a monoclonal antibody recognizing a nuclear antigen expressed by cycling cells) using the APAAP immunoalkaline phosphatase labeling method and a double immunoperoxidase/alkaline phosphatase staining technique. Ki-67-positive neoplastic lymphocytes were plentiful in all large-cell lymphoma cases and in one-third of the small-cell lymphomas. Some benign disorders (patch test biopsies, cutaneous lymphocytoma, lichen planus) also contained many Ki-67-positive lymphocytes. These data indicate the value of using Ki-67 to assess the proliferative capacities of the lymphoid cells in cutaneous infiltrates. Use of this technique in the future may have important prognostic and therapeutic implications in the management of cutaneous lymphoid malignancies.

Three monoclonal antibodies MT1, L60 (Leu-22), and DF-T1, were reported independently as recognising human T cells in routinely processed, paraffin wax embedded tissue. The present study was performed to compare these three reagents in terms of their immunocytochemical reactions and target molecule(s). On Western blotting of white cell extracts the three antibodies reacted with antigens of the same molecular weight (range 110-160 kilodaltons). Furthermore, their immunocytochemical reactivity with normal human cells, as analysed by two-colour flow cytometry, was essentially identical (labelling of monocytes, most T lymphocytes, and weak reactions with some B cells), and the antibodies gave closely similar reactions on 54 white cell derived neoplasms. To identify the target antigen for these three reagents, antibodies from the Third International Workshop on Leucocyte Antigens were reviewed and it was shown that the Western blotting and immunocytochemical reactions of MT1, L60 (Leu-22), and DF-T1 were identical with those of the reagents which defined the CD43 antigen (also known as leucosialin or sialophorin). Furthermore, all these antibodies reacted with cells transfected with a cDNA clone encoding CD43. It is concluded that antibodies MT1, L60 (Leu-22), and DF-T1 all recognise the heavily glycosylated myeloid/lymphoid associated CD43 antigen.

A panel of eight antibodies was used by the alkaline-phosphatase/anti-alkaline phosphatase (APAAP) method to stain peripheral blood films, bone marrow smears, and cytocentrifuge preparations from 29 cases of acute myeloid leukemia. These findings were correlated with the French-American-British (FAB) classification. Leukemic cells from six cases of myeloblastic leukemia (FAB;M1) were predominantly labeled by the antimyeloperoxidase monoclonal antibody (MPO-7). Leukemic cells from the majority of eight cases of myeloblastic leukemia with maturation (FAB;M2) and progranulocytic leukemia (FAB;M3) stained with monoclonal antibodies MPO-7, NP57 (anti-elastase), and EBM11 (antimonocyte/macrophage). Leukemic cells from six cases of myelomonocytic (FAB;M4) and five cases of monocytic (FAB;M5) leukemia were most often labeled with antibodies MPO-7, NP57, and EBM11 as well as monoclonal antibodies Y1/82A (anti-monocyte) and KB90 (against the p150, 95 molecule, CD11c; a monocyte/granulocyte marker), but not with monoclonal antibody C17 (antiglycoprotein IIb/IIIa) and/or monoclonal antibody Y2/51 (antiglycoprotein IIIa). Erythroblasts from a single case of erythroleukemia (FAB;M6) were not labeled with any of the antibodies from this panel. Leukemic cells from two cases of acute megakaryocytic leukemia (FAB;M7) stained strongly with the monoclonal antiglycoprotein IIIa/IIb antibody (C17) and antiglycoprotein IIIa antibody (Y2/51). Staining by the APAAP method with this panel of antibodies was easy to perform, required no expensive instrumentation, and provided useful information in the classification of acute myeloid leukemia.

A new monoclonal antibody, KP1, raised against a lysosomal fraction of human lung macrophages, recognises a fixation-resistant epitope in a wide variety of tissue macrophages (such as Kupffer cells germinal centre, splenic, and lamina propria macrophages), and in granulocyte precursors. Its broad reactivity with cells of the mononuclear phagocytic lineage was established by testing on routinely processed samples of normal and reactive lymphoid tissues. Interdigitating reticulum cells were unstained or showed limited cytoplasmic staining while Langerhans' cells and follicular dendritic reticulum cells were unreactive. KP1 recognises a molecule of about 110 kilodaltons in macrophage-rich human tissue when tested by either immunoprecipitation or Western blotting (although the latter procedure also shows two additional components with molecular weights of 70 and 40 kilodaltons). KP1 should be of considerable value for studying disorders of the monocyte/macrophage system, including both reactive and neoplastic states (such as true histiocytic proliferations).

Two monoclonal antibodies have been produced that react with antigens present on human white cells. These reagents differ from other monoclonal antibodies of similar specificity in that the antigens they recognize are resistant to conventional tissue-fixation and embedding procedures. These reagents can therefore be used in immunocytochemical staining of paraffin-embedded tissue sections. We assessed the practical usefulness of this technique in the histopathological diagnosis of human lymphoid neoplasms by staining a wide range of routine surgical biopsy specimens of normal and neoplastic tissue (gathered from five institutions), using an indirect immunoperoxidase technique. In all 40 cases of non-Hodgkin's lymphoma, positive labeling of neoplastic cells was obtained with one or both antibodies. In contrast, no staining of neoplastic cells was observed in 60 samples of nonlymphoid neoplasms. We conclude that many of the difficulties encountered by histopathologists in distinguishing between lymphoid and nonlymphoid neoplasms may be overcome by immunohistologic labeling with monoclonal antibodies such as the ones we have studied.

The present paper describes the production and characterization of two monoclonal antibodies, K20 and K92. Immunohistological staining showed these two antibodies to be specific for keratinizing epithelium. However, whereas K20 stained all layers of the epidermis K92 reacted with only the suprabasal epidermal layers. Immunoblotting studies with preparations of keratins from both the non-cornified (i.e. the basal, spinous and granular layers) and cornified (stratum corneum) layers of epidermis showed that K20 recognized the 46, 48, 50, 55, 56, 56.5, 59, 61, 62, 64, 65, 66 and 67 kd bands, of which the 50 and 46 kd bands appeared to be masked in tissue sections. In contrast, antibody K92 was more restricted in its activity, recognizing only the 55 and 56 kd bands strongly. These antibodies were used in the study of various epithelial disorders and revealed alterations in the epithelial intermediate filament expression in both benign and malignant disease processes.

The value of immunohistological labeling with a panel of monoclonal antibodies in the diagnosis of routinely processed surgical biopsies has been assessed. The cases examined consisted of an unselected series of tumor biopsies referred during a 12-month period because of doubt as to the nature of the neoplasm and are representative of the type of diagnostic problem regularly encountered in routine surgical pathology. In 30 of the 38 cases studied, reactivity with monoclonal antileukocyte antibody (and nonreactivity with monoclonal antiepithelial antibodies) indicated that the tumor was a lymphoma. Seven of the remaining eight cases gave the reverse reaction pattern and therefore were classified as carcinomas, while one biopsy was unreactive with all antibodies. Review of the clinical details in each case showed that the clinical management in several instances was influenced by establishing the correct diagnosis and it therefore is suggested that immunohistologic examination should be used more widely in the study of tumors that give rise to diagnostic difficulty.