Immunoenzymatic labeling of monoclonal antibodies using immune complexes of alkaline phosphatase and monoclonal anti-alkaline phosphatase (APAAP complexes)

Immunohistochemical demonstration of decreased L-pyruvate kinase in enzyme altered rat liver lesions produced by different carcinogens

Preneoplastic liver lesions were produced in female Wistar rats by application of 25 mg/kg N-nitrosomorpholine (NNM), 14 mg/kg diethylnitrosamine (DENA), 0.075 mg/kg aflatoxin B1 (AFB1) or 160 mg/kg safrole. These carcinogens were administered in two equal doses 12 and 24 h after partial hepatectomy. The animals then received sodium phenobarbital (0.1% in tap water) for up to 410 days. Numerous altered hepatic foci (AHF) and hyperplastic nodules (HN) were detected enzyme histochemically by their negative ATPase reaction after application of AFB1, DENA and NNM; some AHF and HN were also caused by the weak carcinogen safrole. Immunohistochemically these lesions were also L-pyruvate kinase (L-PK)-negative with a high coincidence with regard to their number and area. These results confirm the role of L-PK, an enzyme affecting the pentose phosphate pathway, as a negative marker of preneoplastic liver lesions.

Micrometastatic cancer cells in bone marrow: in vitro detection with anti-cytokeratin and in vivo labeling with anti-17-1A monoclonal antibodies

The detection of early micrometastasis or disseminated single tumor cells poses a problem for conventional diagnosis procedures. Using a panel of monoclonal antibodies against cytokeratin and the 17-1A epithelial antigen we identified immunocytochemically tumor cells in bone marrow of patients with breast cancer (n = 155) and colorectal cancer (n = 57) at the time of surgery of the primary tumor. Monoclonal antibody CK2, recognizing the human cytokeratin component 18 in simple epithelia, appeared to be the most suitable reagent because of its negative reaction with bone marrow samples of the noncarcinoma patients (n = 75). Its specificity was further demonstrated in a double-marker staining procedure using an anti-leukocyte common antigen monoclonal antibody (T200) as counterstain. A comparative analysis showed that immunocytology was clearly superior to conventional cytology (n = 212) and histology (n = 39). In 9.5-20.5% of patients without distant metastasis, tumor cells could be detected in bone marrow. We found a significant correlation between tumor cells in bone marrow and conventional risk factors, such as distant metastasis or lymph node involvement. In a first approach toward immunotherapy we demonstrated in 3 patients that infused monoclonal antibody 17-1A can label single tumor cells in bone marrow in vivo. We then used this approach to follow up 7 patients undergoing 17-1A therapy in an adjuvant clinical trial.

Immunocytological staining reactions of anti-carcinoembryonic antigen, Ca, and anti-human milk fat globule monoclonal antibodies on benign and malignant exfoliated mesothelial cells

A panel of three monoclonal antibodies were used in an immunoalkaline phosphatase staining method on a series of serous effusion samples from cases of mesothelioma, lung carcinoma, and benign disease. The antibodies used were anti-carcinoembryonic (CEA) antigen, Ca, and anti-human milk fat globule membrane antigen. Antibodies to the Ca antigen and human milk fat globule membrane antigen stained 75% and 83% of mesothelioma and 75% of cases of lung carcinoma, respectively. The anti-CEA antibody stained most cases of lung carcinoma strongly but was negative on 11 of 12 cases of mesothelioma and showed weak staining on one case. Benign cases were negative with all three antibodies. These three antibodies may be useful in distinguishing benign and malignant mesothelial cells and lung carcinoma in serous effusions.

AIDS: an overview of the pathology

This article reviews the findings at postmortem examination on AIDS and separately details the surgical pathology of the gastrointestinal tract, liver, lymph nodes, and skin in these patients. Emphasis is placed upon the light microscopic features of the specimens commonly received in surgical pathology so as the promote the ready diagnosis of this important and grave disorder.

Expression of HLA-DR and OKT6 antigens on keratinocytes and dendritic cells in pemphigus

The expression of HLA-DR and OKT6 antigens by epidermal cells in pemphigus was examined by immunohistochemical methods using skin biopsy specimens from human patients with pemphigus vulgaris. Changes in the distribution and subpopulations of Langerhans cells were observed in lesional (involved) skin. HLA-DR-positive, OKT6-negative dendritic cells were numerous and generally confined to the margins of epidermal clefts. OKT6-positive dendritic cells were rare or absent in lesional skin. The HLA-DR-positive, OKT6-negative dendritic cells associated with intraepidermal clefts are most likely functionally active antigen-presenting cells, which may play a role in lesion development. Aberrant expression of HLA-DR molecules by keratinocytes was observed in both involved and uninvolved skin, and may function to facilitate the recognition of surface-bound pemphigus antigen(s) by immunocompetent cells.

Localization of GTP cyclohydrolase I in human peripheral blood smears using a specific monoclonal antibody and an immune-alkaline phosphatase labeling technique

GTP cyclohydrolase I, the enzyme catalyzing the first step in the cofactor biosynthesis for the aromatic amino acid hydroxylases, has been localized in situ. By the use of a monoclonal antibody specific to human GTP cyclohydrolase I, the enzyme has been visualized immuno-enzymatically by alkaline phosphatase monoclonal anti-alkaline phosphatase labeling. In routine blood smears lymphocytes, monocytes/macrophages, and granulocytes show strong intraplasmatic staining. Premature erythrocytes show clear staining of the reticulated cytoplasmatic structure, while mature erythrocytes are completely negative. Neither is there any staining for GTP cyclohydrolase I in the blast cells of a case of T-cell acute lymphoblastic leukemia. These results closely confirm the prior finding that mature erythrocytes as well as most malignant mononuclear cells lack GTP cyclohydrolase I activity, and they indicate that in these cells the enzyme protein may be absent.

Evaluation of epidermal growth factor receptors in bladder tumours

Epidermal growth factor (EGF) receptor expression in 31 primary human bladder tumours was quantitated using both structural and functional assays and the EGF receptor gene in the same tumours was analyzed by Southern blot analysis. Immunocytochemical studies using the EGFR1 monoclonal antibody (Mab) showed a significant correlation between EGF receptor levels and the stage and grade of the tumours. Autophosphorylation assays employed to evaluate the receptor's tyrosine kinase activity gave results which in general were consistent with the immunocytochemical data. Using internally controlled immunocytochemical studies with two Mabs and Southern blot analysis of DNA isolated from the tumours, no evidence was obtained for the production of truncated receptors similar to those encoded by the v-erb-B oncogene. Gene amplification was not found in any of the superficial tumours, but one invasive tumour with high EGF receptor expression had an 8-10 fold amplification of the EGF receptor gene. The EGF receptor isolated from this tumour showed a normal pattern of tyrosine phosphorylation at all three major autophosphorylation sites. Our detailed study is consistent with the correlation previously found between EGF receptor expression and stage and grade of bladder tumours, and suggests that at this level of analysis EGF receptors in bladder tumours are not abnormal in structure or size, autophosphorylation activity, or gene structure.

Biological characterization of human bone tumors. X. The proliferation behavior of macrophages as compared to fibroblastic cells in malignant fibrous histiocytoma and giant cell tumor of bone

Seven giant cell tumors of bone and four malignant fibrous histiocytomas were studied immunohistochemically with different monoclonal antibodies to the mononuclear phagocyte system (MPS), to HLA-DR antigens, and to a proliferation-associated nuclear antigen (KI-67), in order to clarify the role of macrophages in these tumors. A part of the mononuclear cells stained positive with antibodies against the MPS. Antibody 25-F-9 against mature tissue macrophages showed the strongest reaction. The osteoclast-like giant cells also stained positive with this antibody. Fibroblast-like stromal cells, however, showed negative reactions to all antibodies against MPS cells. A double-labeling immunohistological technique was used to detect the proliferating cell population in these tumors. The fibroblast-like cells that were negative for MPS markers, were positively labeled with the monoclonal antibody Ki-67 against a proliferation-associated nuclear antigen, whereas a negative reaction to Ki-67 was seen in cells positive with antibodies to the MPS. These results support the concept that macrophages are a reactive population in these tumors, whereas the fibroblast-like mesenchymal cells are the proliferating tumor cells.

Circulating micromegakaryocytes in myelodysplasia

The alkaline phosphatase-antialkaline phosphatase (APAAP) immunocytochemical staining technique was used to look for circulating cells of megakaryocyte lineage in peripheral blood smears from 67 cases of myelodysplasia. Small numbers of micromegakaryocytes positive for platelet glycoprotein IIIa were found in 23 cases. These cells superficially resemble small lymphoid cells and are hence difficult or impossible to recognise in conventional Romanowsky stained smears. Circulating micromegakaryocytes were found most commonly in more aggressive types of myelodysplasia (such as refractory anaemia with excess blasts (RAEB) and refractory anaemia with excess blasts in transformation (RAEB-t], and their presence may therefore indicate a poor prognosis. Because of the simplicity of this immunocytochemical labelling technique, it could be of wide use in the initial assessment of patients with myelodysplasia, and possibly for the early detection of acute leukaemic transformation.

Giant cell myocarditis associated with lymphoma: an immunocytochemical study

A case of giant cell myocarditis in a patient with non-Hodgkin's lymphoma is reported. To our knowledge, this is a previously unrecorded association and supports the hypothesis that the aetiology of giant cell myocarditis is related to a changed immune state. Immunohistochemical investigation of this case with a panel of monoclonal antibodies against a range of leucocyte and muscle antigens supports the view that the giant cells have a histiocytic rather than a myogenic origin.

Histiocytic necrotizing lymphadenitis without granulocytic infiltration (Kikuchi's lymphadenitis). Morphological and immunohistochemical study of eight cases

Eight examples of histiocytic necrotizing lymphadenitis without granulocytic infiltration (Kikuchi's lymphadenitis) are described. They occurred in young or middle-aged women who usually complained of latero-cervical lymphadenopathy. Serology revealed significant titres for Epstein-Barr virus and Yersinia enterocolitica serogroup 9 in one of eight and one of six tested. All patients fully recovered within 2 months. On histological examination of the lymph nodes large foci of infiltration were observed in the cortex and/or paracortex: they consisted of variable numbers of small lymphocytes, immunoblasts, macrophages and so-called plasmacytoid T-cells; granulocytes were absent. Necrotic changes varied from single pyknotic cells to extensive areas of necrosis. Immunohistochemistry showed that within the lesion the number of macrophages was inversely proportional to the number of peripheral T-lymphocytes and 'plasmacytoid T-cells'. The latter displayed a phenotype (CD4+, CD10+, CD45+) which, in the absence of macrophage-associated antigens, seemed in keeping with their supposed lymphoid nature. In seven cases peripheral T-lymphocytes predominantly expressed the cytotoxic/suppressor phenotype, while in one remaining case a mild predominance of the helper/inducer subset was observed. In the areas with less extensive tissue necrosis, numerous T-immunoblasts expressed both markers of activation and the proliferation-associated nuclear antigen Ki-67. The results of the present study expand the spectrum of our knowledge and allow speculation as to the biology of this disease.

Detection of chlamydial inclusions in cell culture or biopsy tissue by alkaline phosphatase-anti-alkaline phosphatase staining

An immunological technique for detecting Chlamydia trachomatis and Chlamydia psittaci inclusions in infected McCoy cell cultures was developed by using a genus-specific monoclonal antibody to Chlamydia spp., rabbit anti-mouse immunoglobulin G bridging antibody, alkaline phosphatase-anti-alkaline phosphatase (APAAP) monoclonal antibody conjugate, and naphthol AS-phosphate/fast red substrate. Chlamydial inclusions stained red and were easily detected against a background of blue hematoxylin-stained nuclei. After 18 h, inclusions of C. trachomatis serovar L2 LGV434/Bu and C. psittaci strain 6BC were stained by APAAP but not by iodine or Giemsa. At 48 h inclusion counts were significantly higher in the APAAP cultures. Both the APAAP procedure and conventional staining detected 35 of 239 (15%) cultures 48 h after inoculation with urethral or endocervical specimens. However, at 24 h after inoculation 22 of 35 (63%) were positive by APAAP staining while negative by iodine. This immunostain also allowed identification of chlamydial inclusions in endometrial biopsies from patients with tubal factor infertility or pelvic inflammatory disease.

Influence of processing by erythrocyte C3b/C4b receptors (CR1) on binding of immune complexes to Raji cells and polymorphonuclear granulocytes

The binding of 125I-labelled bovine serum albumin (BSA)-anti-BSA immune complexes (IC) to Raji cells and polymorphonuclear (PMN) cells in vitro was studied. The IC were reacted for 1 h at 37 degrees C with normal human serum (NHS) diluted 1:2 in the presence or absence of human erythrocytes (E) before presentation for Raji cells or PMN cells. The IC showed a two to three fold increased binding to C3d, g receptors (CR2) on Raji cells, when E-CR1 had been present during the reaction with NHS, compared to IC similarly reacted with NHS only. Blocking of the E-CR1 by a polyclonal anti-CR1 antibody reduced the subsequent binding of IC to Raji cells to the same level as that obtained with IC reacted with serum only. Binding to PMN granulocytes of IC reacted with NHS in the presence of E-CR1 showed a 60% reduction compared to the binding of IC reacted with NHS only. It is concluded that interaction of complement-reacted IC with CR1 on erythrocytes leads to a more efficient generation of CR2-binding C3d, g-containing IC with reduced reactivity to PMN cells.

Generation of large granular lymphocytes and lymphocyte subset changes linked with cyclophosphamide-induced eosinophilia in rats--and the effects of ciclosporin

Administration of cyclophosphamide (Cy: 150 mg/kg i.p.) to rats 48 h before immunization with a T-dependent antigen (ovalbumin) resulted in a striking absolute eosinophilia in blood, bone marrow, and secondary lymphoid organs after 10 to 14 days. This eosinophilia was preceded by a significant increase in the W3/25+/OX-8+ (T helper/inducer to T cytotoxic/suppressor) ratio in lymph nodes and spleen and accompanied by a pronounced rise in splenic OX-12+ (B cell) numbers. There was also a concomitant increase in cells with the morphology and immunophenotype (OX-8+, OX-19-) of large granular lymphocytes (LGL). It is suggested that the eosinophilia linked with the B lymphocytosis may be due to cell-derived soluble factors, including a possible equivalent of eosinophil differentiation factor (EDF = interleukin 5), which also has B-cell growth factor activity (BCGF II) in mice. Ciclosporin (CsA; 25 mg/kg/day per os) from the time of immunization, did not affect the incidence of W3/25+ cells in spleen or lymph nodes, but abrogated Cy-induced eosinophilia and reduced the extent of B-cell proliferation. In addition, CsA caused a further, marked increase in the incidence of OX-8+, OX-19-LGL within the spleen. The functional role(s) of these latter cells remains to be defined.

Immunophenotyping of acute myeloid leukemia by immuno-alkaline phosphatase (APAAP) labeling with a panel of antibodies

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.

An in vitro model for the study of acute release of von Willebrand factor from human endothelial cells

An in vitro model is described which utilizes human umbilical vein endothelial cells cultured on plastic microcarrier spheres and perfused with serum-free medium. This model was used to study the acute release of von Willebrand factor following stimulation of the cells with putative agonists. Thrombin, plasmin and interleukin-1 were found to release von Willebrand factor. Adrenaline and bradykinin also stimulated release but only at high dosage. 1-desamino-8-D-arginine vasopressin (DDAVP) was inactive.

In situ hybridization: alkaline phosphatase visualization of biotinylated probes in cryostat and paraffin sections

Alkaline phosphatase immunochemical systems were evaluated for use in the demonstration of in situ hybridized biotin-labelled probes in frozen and fixed sections of tonsil. Three probes were used: total genomic DNA, pHY2.1, a human repetitive sequence which hybridizes to a 2.12 KB sequence on the Y chromosome (2000 repeats) and a 2.0 KB sequence on the autosomes (100-200 repeats), and human papilloma virus type II. Indirect, three- and five-stage detection methods were compared on cryostat sections. The indirect method involved the application of a streptavidin, biotinylated alkaline phosphatase sequence. The three-stage procedure comprised a mouse monoclonal anti-biotin, rabbit anti-(mouse immunoglobulin), mouse APAAP system. In the five-stage method the indirect and three-stage reagents were sequentially applied. Alkaline phosphatase was demonstrated using a Fast Red naphthol-capture method. The total genomic DNA probe was used initially to investigate hybridization conditions including the optimum temperature of denaturation, which was found to be higher than previously reported. The five-stage detection method gave the most sensitive results for the Y sequence probe, with intense demonstration of the Y body in male nuclei and autosomal sequences in female nuclei. This method was then applied to fixed tissue sections and gave Y body signals on Bouin's and Carnoy's fixed tissue. On the other hand tissue fixed using formalin-based solutions required proteolytic digestion as a pretreatment to hybridization for a Y body signal. The application of this methodology to viral diagnosis in routine fixed anogenital tissue and cytological preparations was also demonstrated.

Newly produced virgin B cells migrate to secondary lymphoid organs but their capacity to enter follicles is restricted

The migration of recirculating B cells was compared with that of newly produced virgin B cells following passive cell transfer between congenic strains of rats differing in their kappa immunoglobulin light chain (kappa) allotype. The number and location of donor B cells in the secondary lymphoid organs was determined at intervals following transfer by immunohistology using monoclonal antibodies specific for rat kappa allotypes. Recirculating B cells were obtained from thoracic duct lymph while bone marrow from rats depleted of recirculating cells was used as a source of newly produced virgin B cells. B cells from both sources gained immediate access to extrafollicular areas of secondary lymphoid organs rich in interdigitating cells and T cells. However, in lymph nodes extrafollicular B cells were found adjacent to lymphatics and not in the central paracortex. By 8 h after transfer most B cells from thoracic duct lymph were found in follicles. However, the capacity of the bone marrow B cells to enter follicles was very limited. These results are interpreted in relation to previous observations concerning (a) the timing of virgin B cell recruitment into T cell-dependent antibody responses, and (b) the role of B cells in antigen presentation.

The immunohistology of Hodgkin's disease--Reed-Sternberg cells and their variants

Thirty-three cases of Hodgkin's disease were analysed by immunoalkaline phosphatase and immunoperoxidase techniques, using a monoclonal antibody panel, including markers of B-cells, T-cells, macrophages, granulocytes, and the antibody Ki-1. Hodgkin's cells were found to express markers generally regarded as T-cell, B-cell, myeloid, or monocyte associated. Furthermore, heterogeneity of marker expression was also seen within the Hodgkin's cell population in any single case. Morphological and immunohistological analogies between cells involved in antigen presentation and Hodgkin's cells are described, suggesting possible relationships between these cell types. Anti-Leu M1 was not found to be a particularly sensitive marker of Hodgkin's disease under the conditions used in this study.

Phenotype versus immunoglobulin and T-cell receptor genotype of Hodgkin-derived cell lines: activation of immature lymphoid cells in Hodgkin's disease

Three Hodgkin-derived cell lines (L428, L540, and CO) were studied for rearrangements and expression of immunoglobulin and T-cell receptor genes, and their genotype was compared to the phenotype. As far as the genotype is concerned, all 3 cell lines have characteristics of lymphoid cells; L428 of B, and L540 and CO of T-cell origin. L428 cells have one Ig heavy chain allele rearranged to C gamma and transcribed into RNA, while the second is deleted. Furthermore, L428 cells show an unusual immunoglobulin kappa light chain gene rearrangement involving deletion of the kappa constant gene in one allele, while the remaining kappa and lambda loci are in germline configuration. L540 and CO have, in contrast to L428 cells, the immunoglobulin genes in germline and T-cell receptor genes rearranged. The T-cell receptor beta and gamma genes are rearranged in both L540 and CO, whereas a rearrangement in the alpha locus was detected in L540 cells only. RNA of the size of functional beta chain transcripts was found in CO cells and of the size of functional alpha chain transcripts in L540 cells. All 3 cell lines are classified as immature lymphoid cells with respect to the limited expression of B- and T-cell antigens, respectively, and to the incomplete expression of their antigen receptor. The immaturity of lymphoid differentiation contrasts with the expression of activation antigens, i.e. Ki-1, Ki-24, HLA-DR, and IL-2 receptor. The immaturity of the cells excludes the possibility that the cells were activated along the physiological pathway, i.e. by interaction of the cell with antigen. The results obtained on the cell lines are in accordance with in vivo studies and suggest that Hodgkin and Sternberg-Reed cells are immature lymphoid cells which are activated by a still unknown mechanism.

Production of monoclonal antibodies against glucose oxidase, alkaline phosphatase and peroxidase. Their application in a highly sensitive antigen spot microassay

The production of monoclonal antibodies against peroxidase, alkaline phosphatase and glucose oxidase and the use of the respective enzyme monoclonal anti-enzyme complexes in immunoassays are described. A micromethod using nitrocellulose membranes as solid phase was developed. This microassay has the advantage of being a rapid and simple test procedure, using only 0.2 microliter of antigen solution and 25 microliter of test reagents. A high sensitivity was achieved by repeated incubation of monoclonal enzyme anti-enzyme complexes bridged by anti-mouse immunoglobulin. As little as 200 pg human IgG and 400 pg human IgM could be detected. The glucose oxidase assay together with the alkaline phosphatase assay displays the highest sensitivity and has significant advantages including easy evaluation due to high color contrast of the enzymatic reaction, availability of non-toxic substrate reactions, and no interference with endogenous enzyme activity in mammalian antigen preparations.

Immunohistochemical evaluation of bone marrow involvement in hairy cell leukemia during interferon therapy

Bone marrow biopsies from 7 patients afflicted with hairy cell leukemia were studied with a panel of monoclonal antibodies at different intervals during alpha recombinant interferon therapy. Monoclonal antibodies Dako-LC and F 8.11.13 were used because they are highly reactive with hairy cells, and 82H3 and LeuM 1 were also utilized to identify respectively the residual hemopoietic and myeloid tissue. All antibodies are reactive on sections of formalin-fixed, paraffin-embedded biopsy material. Before therapy a uniform hairy cell infiltrate was present and very little tissue was visible even after immunohistochemical staining. During therapy, identification of hairy cells in routine biopsies was difficult, since they were mixed with normal cells and the bone marrow was generally hypoplastic. Immunohistochemical stains seem to allow better identification of hairy cells and a more precise estimate of the degree of repopulation by normal bone marrow cells. It was evident, especially after immunocytochemical analysis, that interferon drastically reduced the extent of the infiltrate and allowed recovery of normal hemopoiesis, but did not produce complete remissions.

ins(6;11) in a case of peripheral T-cell lymphoma

Cytogenetic investigation of lymph node-derived cells taken from a peripheral T-cell lymphoma patient revealed an insertion of the segment 11q21q25 into the band p22 of chromosome #6 as the only anomaly. The probable role of the three rearranged chromosomal regions on the development of this neoplasia is discussed.

Epidermal growth factor receptors in lung tumours

Immunocytochemical analysis of epidermal growth factor (EGF) receptor expression was carried out on frozen sections of 109 primary lung tumours resected at the Brompton Hospital from February 1984 to May 1985. Tumours with detectable levels of this proto-oncogene protein were significantly more frequent among squamous cell carcinomas than among other types of lung tumour. No truncated EGF receptors were detected in the tumours using two monoclonal antibodies (Mabs) directed against different portions of the receptor (EGFR1 and F4). Mab F4 is the first antibody to the EGF receptor to show reactivity in paraffin sections. Southern blot analysis of a subset of the tumours detected amplification of the EGF receptor gene in squamous cell carcinomas but not in adenocarcinomas. The one carcinosarcoma examined had a re-arranged and amplified EGF receptor gene. Measurement of EGF receptor expression in lung tumours can be of diagnostic value and may prove to be useful in the development of antibody-directed therapy.

Intermediate filaments cytokeratin and vimentin in ovarian sex cord-stromal tumours with correlative studies in adult and fetal ovaries

The expression of the intermediate filaments cytokeratin and vimentin were studied immunohistochemically in a series of ovarian sex cord-stromal tumours (26 adult and juvenile granulosa cell tumours, 11 thecomas, six fibromas, three Sertoli-Leydig cell tumours and 1 sex cord tumour with annular tubules). Contrary to previous reports, granulosa cell tumours expressed cytokeratins as well as vimentin. Thecomas and fibromas expressed vimentin only. In Sertoli-Leydig cell tumours and the sex cord tumour with annular tubules, both cytokeratins and vimentin were detected. Correlative studies in adult ovaries showed that patterns of expression in non-neoplastic granulosa, thecal and stromal cells correspond to their neoplastic counterparts. Investigation of fetal ovaries demonstrated that these patterns of intermediate filament expression exist from relatively early stages of development. Ovarian surface epithelium and rete ovarii, like granulosa cells, co-expressed cytokeratin and vimentin. The demonstration of cytokeratins in granulosa cells and the reported presence of desmosomes and tonofilaments, suggests the epithelial nature of these cells although not clarifying their histogenesis. The presence of both these intermediate filaments in granulosa and Sertoli-Leydig cell tumours as well as in some ovarian carcinomas which may mimic them, limits their value in differential diagnosis between these tumour groups.

Immunoenzymatic staining methods for simultaneous demonstration of chromosomes and cell surface markers

We have developed immunocytochemical staining methods for the simultaneous phenotypic and karyotypic characterization of individual cells. Following a mild hypotonic pretreatment, isolated cells are cytocentrifuged on poly-L-lysine coated slides, fixed in formol buffered acetone, and subsequently labeled with monoclonal antibodies utilizing indirect immunoenzymatic staining procedures with horseradish peroxidase (HRP) or alkaline phosphatase monoclonal anti-alkaline phosphatase (APAAP) as second antibodies. Preparations are refixed consecutively in methanol and 45% acetic acid and counterstained with either "Stains-all" (HRP labeled preparations) or Giemsa (APAAP labeled preparations). C-banding or weak G-banding, which allows the identification of individual chromosomes, can be induced in labeled as well as unlabeled mitotic cells by Ba(OH)2 and/or 2 X SSC treatment after refixation, respectively. Our method has been successfully tested with a variety of monoclonal antibodies against lymphoid, myeloid, erythropoietic, and thrombopoietic cell surface antigens. It is fast, allows the adjustment of the intensity of cell surface staining, and results in permanent preparations suitable for light microscopic analysis.

Human lung tumours: does intermediate filament co-expression correlate with other morphological or immunocytochemical features?

Co-expression of intermediate filaments is being increasingly reported for many human tumours including carcinoma of the lung. However, it is unclear whether such findings are unusual or restricted to a group of highly atypical tumours. In the present study the pattern of co-expression of intermediate filaments in 94 human lung tumours has been correlated with light and electron microscopical features which are thought to be atypical for particular tumour types. These same aberrant patterns of intermediate filament co-expression have also been compared with the proliferative rate of these tumours as determined by labelling with the monoclonal antibody Ki67. The results of this study have shown that the aberrant expression of intermediate filaments is not a feature unique to a group of highly unusual tumours but is found throughout the spectrum of lung cancer. The implications of these findings for the use of anti-intermediate filament antibodies in pulmonary pathology are discussed with suggestions for future directions which might be taken in this field.

Immunophenotyping of the cutaneous infiltrate and of the mononuclear cells in the peripheral blood in patients with atopic dermatitis

Fourteen adult patients with chronic atopic dermatitis and active skin lesions had a skin biopsy and venous blood sample taken on the same day. Absolute numbers of circulating lymphocytes were normal in all patients. Fluorescence-activated cell sorter (FACS) analysis revealed normal numbers of total T lymphocytes and T-helper and T-suppressor subsets (helper:suppressor ratio, 2:1) in the atopic patients' peripheral blood, but an increase in circulating B lymphocytes and in HLA-D-related antigen-bearing cells. The skin biopsy showed a dermal infiltrate of predominantly T-helper lymphocytes (helper:suppressor ratio, 7:1). These cells showed strong HLA-DR plasma membrane staining. There was no HLA-DR staining in the membranes of epidermal keratinocytes. Using a monoclonal antihuman IgE, positive staining was observed in the dermis, though none was identified in the epidermis. The dermal anti-IgE staining was concentrated around clusters of T lymphocytes.

Nonlymphoblastic T-cell lymphoma in children

Three children with nonlymphoblastic, non-Hodgkin's lymphomas, showed morphologic features that suggested nonlymphoblastic T-cell origin. Tissue for immunologic study was available from two of the three patients; both showed immunophenotypes of T-cells. Although nearly all T-cell lymphomas in children are lymphoblastic based on morphology, nonlymphoblastic T-cell lymphomas do occur in pediatric patients.

Expression of a Hodgkin and Reed-Sternberg cell associated antigen (Ki-1) in cutaneous lymphoid infiltrates

Skin biopsy specimens from normal skin and from 115 patients with benign dermatoses, pre- or pseudo-malignant disorders or malignant cutaneous lymphomas have been examined immunohistologically for expression of the Reed-Sternberg cell associated antigen CD30 detected by monoclonal antibodies Ki-1 and Ber-H2. The antibodies stained the atypical cells in lymphomatoid papulosis, a proportion of the neoplastic cells in some cases of mycosis fungoides and most of the neoplastic cells in six large cell anaplastic/pleomorphic non-Hodgkin's lymphomas. The lymphoid cells in all other specimens were Ki-1- and Ber-H2-negative. In all cases, expression of the Ki-1/Ber-H2 antigen was accompanied by expression of activation and proliferation associated markers (i.e., HLA-DR, IL-2 receptor, transferrin receptor and the Ki-67 nuclear antigen). These data indicate the value of antibodies Ki-1 and Ber-H2 in distinguishing between lymphomatoid papulosis and other types of pre- or pseudo-malignant disorders and support the view that lymphomatoid papulosis, Hodgkin's disease and some types of non-Hodgkin's lymphoma constitute a spectrum of related disorders, originated from activated lymphoid cells.

Immunoscintigraphy with 99mTc labelled F(ab')2 fragments of an anti melanoma monoclonal antibody (225.28S) in patients with metastatic malignant melanoma

Immunoscintigraphy was performed in 25 patients with malignant melanoma using a 99mTc labelled monoclonal antibody (225.28S). In four cases, imaging was repeated following treatment with recombinant gamma interferon. In 11 cases, tissue samples of metastatic lesions were investigated for the expression of melanoma associated antigens by immunohistochemical techniques. Overall, 59% of known lesions were detected by imaging. The highest rates of detection were in bone, liver and lymph nodes and the lowest in lung, stomach and bowel. Six lesions were detected which had not shown up on routine clinical and radiological examination. There was no evidence of enhanced or induced HMW-MAA expression following interferon treatment. This technique has been found to be useful in staging patients and has been free from side effects.

Genotypic analysis of cutaneous T-cell lymphomas

The gene encoding the beta-chain of the T-cell antigen receptor (TCR) has been analyzed for evidence of rearrangement in skin, blood, and lymph node specimens from 23 cases of known or suspected cutaneous T-cell lymphoma (CTCL). Two cutaneous large cell lymphomas, 4 cases of Sézary syndrome, and 5 cases of advanced (tumor) stages of mycosis fungoides showed clonal rearrangement of the TCR beta-chain gene in all samples, including lymph nodes in which histologic examination revealed only dermatopathic lymphadenitis. These results indicate that DNA analysis provides a valuable means for improving the diagnosis of extracutaneous disease in advanced stages of CTCL. In contrast, the gene was in a germline configuration in all samples from 12 patients with plaque stages of mycosis fungoides or suspected early CTCL, suggesting that in these 2 conditions the T-cell proliferation is either polyclonal or contains very few monoclonal (i.e., neoplastic) cells.

Sequential immunophenotypic study of lymphoid infiltrate in allergic and irritant reactions

Sequential biopsies (4-72 h) of early allergic and irritant patch test reactions have been examined immunohistologically for reactivity with 19 monoclonal antibodies against antigens on lymphoid cells in order to investigate the nature/origin of the infiltrating lymphoid cells and assess their state of activation/proliferation. The composition of the infiltrates was similar in allergic and irritant reactions and consisted of T-lymphocytes of helper/inducer types in association with T-cell accessory cells, i.e., Langerhans cells and HLA-DR-positive macrophages. No differences in expression of T-cell or macrophage associated antigens were seen in early as opposed to late biopsies. In contrast, the proportion of cells positive for markers associated with activation (interleukin-2 receptor) or proliferation (transferrin receptor, the Ki-67 nuclear antigen) of lymphoid cells was found to increase with time in both types of reaction. These data substantiate the view that T-cell immune reactions are implicated in both allergic and toxic patch test lesions, and indicate that the lymphocytes in the infiltrates are activated and proliferate.

Cytokeratin expression in smooth muscle and smooth muscle tumours

The expression of cytokeratin intermediate filaments by a tumour has been accepted as evidence of an epithelial origin. Although there have been anecdotal reports of cytokeratin expression within tissues and neoplasms of non-epithelial origin, particularly muscle, there have been no comprehensive studies of its frequency and distribution. In order to investigate this we have studied 51 cases of normal smooth muscle and benign and malignant smooth muscle tumours using a panel of monoclonal antibodies against a range of intermediate filaments (cytokeratins, desmin and vimentin). Cytokeratin expression was noted overall in 50% of normal, benign and malignant smooth muscle tissues. Such expression tended to have a focal or patchy distribution. No case expressed cytokeratins in the absence of both desmin and vimentin. The implication of these findings for diagnostic immunocytochemistry is that intermediate filaments alone are not completely reliable markers of tumour histogenesis and should be used as part of a larger panel of monoclonal antibodies.

The ontogeny of the interleukin 2 receptor expression and of the interleukin 2 responsiveness in the rat thymus

The ontogeny of the interleukin 2 receptor (IL 2 R) expression and of the IL 2 responsiveness has been investigated in the rat thymus. In tissue sections, IL 2 R-bearing cells were first detected at day 16 of gestation using the anti-IL 2 R mAb ART-18. In contrast to mice, IL 2 R-bearing cells of the rat are localized mainly in the thymic medulla from the first day of the corticomedullary compartimentalization, and not in the cortex. They are found in regions with a high expression of MHC class II antigens. The proportion of IL 2 R-bearing cells increases during gestation, reaches a peak at the first day after birth and declines to the adult level in the following weeks. The appearance of medullary localized IL 2 R-bearing cells is paralleled with the capacity of the thymocytes to proliferate in response to IL 2 without any additional stimuli.

Stimulation of proliferation, differentiation, and function of human cells by primate interleukin 3

Cloned gibbon interleukin 3 (gIL-3) was found to stimulate the proliferation and differentiation of human bone marrow cells to produce day-14 granulocyte, macrophage, granulocyte-macrophage, and eosinophil colonies in semisolid agar. In the presence of normal human plasma, gIL-3 stimulated megakaryocytes. In methylcellulose cultures, it stimulated erythroid colonies in the presence, but not in the absence, of erythropoietin. When mature human leukocytes were used, gIL-3 stimulated the function of purified mature eosinophils as measured by the capacity to kill antibody-coated target cells, to produce superoxide anions, and to phagocytize opsonized yeast particles in a manner similar to recombinant human granulocyte-macrophage colony-stimulating factor. In contrast, gIL-3 did not significantly stimulate any of the neutrophil functions tested, whereas human recombinant granulocyte-macrophage colony-stimulating factor was active in these assays. Among cytokines that are active on human hematopoietic cells, gIL-3 thus has a distinct set of functions and may predict the range of actions of the human molecule.

Occupational dermatitis in bakers: a clue for atopic contact dermatitis

6 patients are described who developed contact dermatitis after cereal contact on atopic skin for periods of 2 to 20 years. 2 patients were wheat flour patch-test-positive. They had punch biopsies taken for standard histological and immunohistochemical investigation by labeling with monoclonal antibodies, anti-DR and anti-IgE. Sections showed features of contact dermatitis. There were many dendritic cells located perivascularly in the papilla and in the epidermidis, intensely positive for monoclonal anti-IgE antibody. In control atopic subjects, there were a few perivascular IgE positive cells, probably mastocytes. This study shows that there may be a relationship between some allergens and atopic eczema in patients exposed to them in the course of their work. In some cases, there was a true allergic contact dermatitis, seen through the clinical and histological characteristics, and the results of immunohistochemical study.

An improved method for recovery of secretory immunoglobulins and lymphocytes from the nasal mucosa

The difficulty of obtaining adequate specimens for assay has severely restricted in vivo investigations of local immune responses in humans. Washing the posterior nasopharynx for an extended period using chilled saline to stimulate serous secretions has improved yields of both secretory immunoglobulins and functionally competent immunocytes. The proportions of T- and B-cells found in such washings appear to differ from those found in blood.

An immunohistochemical study of differentiation in malignant fibrous histiocytoma

Immunohistochemistry was used to examine 10 cases of malignant fibrous histiocytoma. Malignant cells in all cases expressed vimentin and in eight there was co-expression of either desmin or neurofilament, both of these being present in four cases. In addition, cytokeratin was found in one case. In each tumour, a population of small cells was identified which had the staining characteristics of benign macrophages, and this was distinct from the tumour cells. This study supports the concept that malignant fibrous histiocytoma is a tumour of mesenchymal cells rather than of histiocytes and emphasizes the diversity of its cytostructure.

Complement membrane attack (MAC) in idiopathic IgA-glomerulonephritis

Antigens of the membrane attack complex of complement (MAC), such as C5, C6, C9 and MAC-related neoantigen(s), were demonstrated in the mesangium of 23 cases with IgA-glomerulonephritis (IgA-GN) and two cases with Henoch-Schönlein purpura nephritis (HSP). High specificity of the polyclonal antibodies was verified by dot-blot analysis. Control specimens lacking immunoglobulin deposits were negative for MAC-related antigens. Markers of classical pathway activation (Clq and C4) were observed only in two of 24 and one of 23 cases of IgA-GN and HSP, respectively. Glomerular distribution patterns (mesangial vs. mesangio-peripheral) of immunoglobulin or complement deposits were correlated for IgA and C3b/iC3b (P less than 0.002), for IgA and properdin (P less than 0.002) and for IgA and MAC neoantigens (P less than 0.01). Double immunostaining experiments revealed co-localization of IgA and MAC neoantigens at identical mesangial and capillary sites. Glomerular distribution of the less pronounced IgG or IgM deposits did not correlate with that of any complement-derived antigen. The pattern of MAC-related antigens was found to be uniformly either mesangial or mesangio-peripheral. Staining for MAC-related antigens was less intense in IgA-GN cases with minimal glomerular lesions than in cases with more advanced non-sclerosing lesions. IgA, C3d, and MAC localized in corresponding glomerular sites. This is consistent with complete local activation of complement by glomerular IgA deposits via the alternative pathway. The possibility exists that MAC plays a pathogenetic role, such as by irritation of bystander cells, in IGA-GN and HSP.

Immunohistochemical determination of growth fractions in human permanent cell lines and lymphoid tumours: a critical comparison of the monoclonal antibodies OKT9 and Ki-67

OKT9 and Ki-67 monoclonal antibodies have recently been proposed as useful tools for evaluating the growth fraction in malignant tumours, with special reference to non-Hodgkin's lymphomas. In particular, while the former is commonly thought to detect a transferrin receptor present on the cytoplasmic membrane of proliferating cells, the latter recognizes a nuclear antigen, which is expressed in G1, S, G2 and M phase of continuously cycling elements. To further verify their reliability, OKT9 and Ki-67 were applied to seven permanent cell lines (four myeloid and three B-lymphoblastoid) and 100 lymphoid tumours (70 non-Hodgkin's and 30 Hodgkin's lymphomas) phenotypically characterized on frozen sections. The results obtained showed that OKT9 and Ki-67 cannot be employed as equivalent means in assessing the growth fraction. In fact, OKT9 is directed to a transferrin receptor which is not only expressed by proliferating cells, but also by some resting elements. On the other hand, Ki-67 provides a nuclear, easily detectable positivity which is restricted to proliferating cells only. Therefore, it seems to represent the only monoclonal which can confidently be employed in the assessment of the growth fraction. Furthermore, the present study underlines that the immunocytochemical analysis of the proliferation rate in tumours gives similar information to the radionucleide uptake assay, while it represents a more sensitive method than the cytofluorimetric evaluation of the DNA content.

A comparison of three methods for the determination of the growth fraction in non-Hodgkin's lymphoma

The proliferation rate of non-Hodgkin's lymphomas (NHL) was estimated by using 3 different methods. In cell suspension we determined the proportion of cells in cycle with the monoclonal antibody (Mab) Ki-67 and also in S-phase after the incorporation of bromo-deoxyuridine (BrdU) utilizing Mab anti-BrdU. In low grade lymphomas 3.5 +/- 1.6% of the cells were in cycle and 1.2 +/- 0.9% in S-phase, the corresponding values for high grade lymphomas were 22.5 +/- 18.7% and 8.9 +/- 7.8% respectively. Frozen sections of NHL were reacted with an antibody to the transferrin receptor (TR) and Ki67 as markers for proliferative activity. A high number of TR positive cells was found in low grade lymphomas of all histological types, whereas Ki67 positivity correlated closely with grading. With a few exceptions, low grade lymphomas contained less than 25% Ki67 positive cells within the tumour cell population. This observation is relevant to treatment strategies for low grade NHL.

The alkaline phosphatase anti-alkaline phosphatase technique in dermatopathology

The APAAP technique is an unlabelled antibody bridge technique which can be used on either frozen or paraffinembedded sections. One applies first a monoclonal antibody, then a polyclonal bridge antibody, and finally a soluble complex of alkaline phosphatase and monoclonal mouse anti-alkaline phosphatase. Subsequently, the enzyme label is developed with a naphthol salt and new fuchsin as a dye. This technique was used in our laboratory on frozen and/or paraffin embedded sections by using 15 different monoclonal antibodies, which are commercially available. The reaction product was bright red and could easily be distinguished from the brown color of melanin, which makes the APAAP technique particularly suitable for dermatopathology.

Expression of intermediate filament proteins in normal and diseased thyroid glands

A total of 67 samples from normal and pathological thyroid glands were stained (as formalin fixed paraffin sections) with a panel of monoclonal antibodies directed against intermediate filament proteins. The study confirmed previous reports of cytokeratin and vimentin coexpression in primary thyroid carcinomas, but coexpression was also detected in normal thyroid and in a range of benign conditions including follicular adenomas, Hashimoto's thyroiditis, and diffuse hyperplasia (thyrotoxicosis). Prekeratin expression was found (using antibodies recognising higher molecular weight cytokeratins) predominantly in areas of squamous change, independent of the underlying thyroid pathology. This study does not therefore support previous findings that prekeratin expression provides a reliable means of distinguishing follicular pattern papillary carcinoma from follicular carcinoma with its poorer prognosis or that it helps distinguish benign from malignant papillary lesions. No evidence of desmin or neurofilament expression was seen, and in particular, neurofilaments could not be detected in any of the cases of medullary carcinoma studied.

Immunohistological staining of reactive mesothelium, mesothelioma, and lung carcinoma with a panel of monoclonal antibodies

A panel of seven monoclonal antiepithelial antibodies of different specificities, including anticytokeratin, human milk fat globule membrane, C, and carcinoembryonic antigen (CEA) were used with the alkaline phosphatase-antialkaline phosphatase (APAAP) immunostaining technique to determine their value in the differentiation between benign and malignant mesothelial cells and lung carcinoma in histological preparations. The anticytokeratin antibody reacted strongly with all cases of reactive mesothelium, mesothelioma, and lung carcinoma. Antibodies to human milk fat globule membrane and the Ca antigen stained mesothelioma and carcinoma and 43% of cases of reactive mesothelium. Staining for carcinoembryonic antigen was not detected in reactive mesothelium or mesothelioma, but was present in most of the lung carcinomas. CEA seemed to be the single most useful marker in distinguishing carcinoma from mesothelioma in that a positive reaction for CEA would indicate carcinoma rather than mesothelioma.

Spongiform encephalopathy in a patient with acquired immune deficiency syndrome (AIDS)

The histological and ultrastructural findings of subacute spongiform encephalopathy (SSE) are described in the cerebral cortex and basal ganglia of a homosexual patient who died with acquired immune deficiency syndrome (AIDS). It is suggested that SSE, beside the diffuse AIDS leukoencephalopathy, might be another morphological substrate of the AIDS dementia complex.

Immunohistochemical demonstration of vitronectin in association with elastin and amyloid deposits in human kidney

The multifunctional glycoprotein vitronectin, also called serum spreading factor and S-protein of complement, is a potent inducer of cell adhesion and spreading in vitro, and also has a regulatory function in the complement and coagulation pathways. It is present both in plasma and tissue. Recently, vitronectin immunoreactivity was demonstrated in the elastic fibres of normal human skin. Normal and amyloid kidney tissue was investigated for vitronectin immunoreactivity using polyclonal and monoclonal antibodies in an avidin-biotin-peroxidase complex technique and in an alkaline phosphatase anti-alkaline phosphatase complex technique. Vitronectin was found in the elastic layers of normal vessel walls, and in glomerular sclerotic lesions in cases of benign nephrosclerosis, but not in normal glomeruli. Strong specific vitronectin immunoreactivity was found in the amyloid deposits in kidneys from cases with amyloid A type amyloidosis, and in cases with amyloid light chain type amyloidosis. Structures immunostainable with anti-amyloid A antiserum were invariably immunostainable with anti-vitronectin. An antiserum against serum amyloid P component stained the same structures as did the anti-vitronectin antibodies, and in addition stained normal glomerular basement membranes. In conclusion, vitronectin immunoreactivity was demonstrated in elastic tissue, in amyloid deposits and in sclerotic lesions in human kidney.