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

Low flow: Selecting a limited flow cytometry panel where resources are constrained

Diagnosis and treatment of patients with haematological malignancies (HM) is hampered by access to pathology services in resource-limited settings (RLS). Internationally accepted guidelines and diagnostic criteria for HM require access to sophisticated analysis including comprehensive flow cytometry (FCM) for minimum essential diagnosis and treatment, which is technically challenging in RLS. This review will define these shortcomings and examine the use of limited FCM panels in RLS. While a consensus guideline exists for a limited chronic lymphocytic leukaemia (CLL) FCM panel, this has yet to be validated in a large cohort. Currently, there are no consensus-based and resource-stratified diagnostic protocols defining limited FCM panels for the diagnosis of acute leukaemia where resources are limited. There is an unmet need for such guidelines, supported by evidence, for the diagnosis of the most common HM. This systematic review defines consensus-based limited FCM panels from the literature that may be used in the interim.

Evaluation of Grading Estrogen Receptors in Breast Cancer Using Fully Automated Rapid Immunohistochemistry Based on Alternating-Current Electric Field Technology

BACKGROUND

Immunohistochemistry (IHC) is crucial for determining cancer treatments. We previously developed a rapid IHC method and have now developed a fully automated rapid IHC stainer (R-Auto). This study aimed to evaluate the clinical reliability of the R-Auto protocol for staining estrogen receptors (ERs) in breast cancer specimens and evaluate the staining performance.

METHODS

Between January 2015 and June 2020, 188 surgical specimens collected from breast cancer patients treated at our hospital were evaluated via ER staining using R-Auto, conventional manual IHC, and a commercial autostainer. The specimens were scored using Allred scores, after which the staining results were compared between R-Auto and conventional IHC or the commercial autostainer. Weighted kappa coefficients and AC1 statistics were used to assess the agreement between the methods.

RESULTS

The AC1 statistic for comparison between R-Auto and conventional IHC was 0.9490 (0.9139-0.9841), with a 95.7% agreement rate, and that for comparison between R-Auto and the commercial autostainer was 0.9095 (0.8620-0.9570), with a 92.6% agreement. There was, thus, substantial agreement between R-Auto and both conventional IHC and the commercial autostainer. However, R-Auto shortened the time required for IHC from 209 min with conventional IHC to 121 min.

CONCLUSIONS

R-Auto enables a good staining performance in a shorter time with less effort.

Preosteoclast plays a pathogenic role in syndesmophyte formation of ankylosing spondylitis through the secreted PDGFB - GRB2/ERK/RUNX2 pathway

OBJECTIVES

Ankylosing spondylitis (AS) is a chronic inflammatory disease that mainly affects the sacroiliac joint and spine. However, the real mechanisms of immune cells acting on syndesmophyte formation in AS are not well identified. We aimed to find the key AS-associated cytokine and assess its pathogenic role in AS.

METHODS

A protein array with 1000 cytokines was performed in five AS patients with the first diagnosis and five age- and gender-matched healthy controls to discover the differentially expressed cytokines. The candidate differentially expressed cytokines were further quantified by multiplex protein quantitation (3 AS-associated cytokines and 3 PDGF-pathway cytokines) and ELISA (PDGFB) in independent samples (a total of 140 AS patients vs 140 healthy controls). The effects of PDGFB, the candidate cytokine, were examined by using adipose-derived stem cells (ADSCs) and human fetal osteoblast cell line (hFOB1.19) as in vitro mesenchymal cell and preosteoblast models, respectively. Furthermore, whole-transcriptome sequencing and enrichment of phosphorylated peptides were performed by using cell models to explore the underlying mechanisms of PDGFB. The xCELLigence system was applied to examine the proliferation, chemotaxis, and migration abilities of PDGFB-stimulated or PDGFB-unstimulated cells.

RESULTS

The PDGF pathway was observed to have abnormal expression in the protein array, and PDGFB expression was further found to be up-regulated in 140 Chinese AS patients. Importantly, PDGFB expression was significantly correlated with BASFI (Pearson coefficient/p value = 0.62/6.70E - 8) and with the variance of the mSASSS score (mSASSS 2 years - baseline, Pearson coefficient/p value = 0.76/8.75E - 10). In AS patients, preosteoclasts secreted more PDGFB than the healthy controls (p value = 1.16E - 2), which could promote ADSCs osteogenesis and enhance collagen synthesis (COLI and COLIII) of osteoblasts (hFOB 1.19). In addition, PDGFB promoted the proliferation, chemotaxis, and migration of ADSCs. Mechanismly, in ADSCs, PDGFB stimulated ERK phosphorylation by upregulating GRB2 expression and then increased the expression of RUNX2 to promote osteoblastogenesis of ADSCs.

CONCLUSION

PDGFB stimulates the GRB2/ERK/RUNX2 pathway in ADSCs, promotes osteoblastogenesis of ADSCs, and enhances the extracellular matrix of osteoblasts, which may contribute to pathological bone formation in AS.

Developing Digital Photomicroscopy

(1) The need for efficient ways of recording and presenting multicolour immunohistochemistry images in a pioneering laboratory developing new techniques motivated a move away from photography to electronic and ultimately digital photomicroscopy. (2) Initially broadcast quality analogue cameras were used in the absence of practical digital cameras. This allowed the development of digital image processing, storage and presentation. (3) As early adopters of digital cameras, their advantages and limitations were recognised in implementation. (4) The adoption of immunofluorescence for multiprobe detection prompted further developments, particularly a critical approach to probe colocalization. (5) Subsequently, whole-slide scanning was implemented, greatly enhancing histology for diagnosis, research and teaching.

Developing Monoclonal Antibodies for Immunohistochemistry

The experiences of a laboratory which pioneered the application of monoclonal antibodies to diagnostic histochemistry is described. This was achieved in four key steps: (1) Monoclonal antibodies were successfully produced to replace the difficult-to-produce and limited polyclonal antibodies available for immunohistochemistry. (2) Monoclonal antibodies were produced to improve the immunoenzymatic detection of bound antibodies, using immunoperoxidase or alkaline phosphatase, increasing sensitivity and allowing the use of two chromogens when applied together. The availability of a reliable alkaline phosphatase-based detection allowed the detection of antigens in tissues with high endogenous peroxidase. (3) Methodologies were developed to unmask antigens not detected in routinely processed paraffin-embedded tissue. (4) Synthetic peptides were used as immunising antigens for the direct production of specific molecules of diagnostic interest. This was expanded to include recombinant proteins. Many reacted with fixed tissue and recognised homologous molecules in other species. In addition to these developments, the laboratory promoted the collaboration and training of researchers to spread the expertise of monoclonal production for diagnosis.

Immunocytochemical Labelling of Haematological Samples Using Monoclonal Antibodies

I reflect on my experience working with David Y. Mason in the Leukaemia Research Laboratories in the Nuffield Department of Pathology at the University of Oxford in the early 1980s. This was soon after the first monoclonal antibodies had been produced, which led to an exciting and productive time in biological discovery and pathology diagnostics. A specific focus in the laboratory was the development of immunoenzymatic staining methods that would enable monoclonal antibodies to be applied in diagnostic practice. This paper describes the work that led to the performance of immuno-alkaline phosphatase staining on blood and bone marrow smears, the success of which changed leukaemia diagnosis.

Clinical Characteristics and Histopathological Patterns of Hodgkin Lymphoma and Treatment Outcomes at a Tertiary Cancer Center in Ethiopia

PURPOSE

In developing countries, Hodgkin lymphoma (HL) affects the young population. In Ethiopia, nearly 70% of the population are < 35 years of age. Therefore, this study aimed to elucidate the age distribution, histopathologic patterns, clinical characteristics and treatment outcomes of HL in Ethiopia.

MATERIALS AND METHODS

Data from clinical records of 133 consecutive patients with HL between 2014 and 2019 were reviewed and collected. Formalin-fixed paraffin-embedded tissue blocks of HL cases were collected and used for subtype classification.

RESULTS

A total of 68.4% (91) of the patients were male; male-to-female ratio was 2.2:1. The median age was 22 years. The age distribution was 57.1% (76), 30.8% (41), and 2.3% (3) for the age groups (10-29), (30-59), and (60-69) years, respectively. Thirteen percent (12) were associated with HIV. The majority of the cases, 50.4% (67), were of the mixed-cellularity (MCCHL) subtypes and 30% (40) nodular-sclerosis (NSCCHL). Most HIV-associated cases (60%, 6) were of the MCHL subtype. The 4-year overall survival (OS) was 83.1%. The 4-year OS of early-stage patients was 100% and advanced-stage patients with low-risk (International Prognostic Score [IPS] ≤ 2) and high-risk (IPS ≥ 3) were 94.1% and 62.9%, respectively. All patients who received combined-therapy survived, whereas those who received doxorubicin, bleomycin, vinblastine, and dacarbazine only showed a 4-year OS rate of 77.9%.

CONCLUSION

HL affects the youngest and most productive population in Ethiopia. The treatment outcome is favorable in both HIV-associated and non-HIV-associated HL. However, the study population was likely a highly selected group as the majority of the Ethiopian population do not have access to specialized care.

Cytokeratin-positive cells in the bone marrow from patients with pancreatic, periampullary malignancy and benign pancreatic disease show no prognostic information

Background

Pancreatic and periampullary carcinoma are aggressive tumours where preoperative assessment is challenging. Disseminated tumour cells (DTC) in the bone marrow (BM) are associated with impaired prognosis in a variety of epithelial cancers. In a cohort of patients with presumed resectable pancreatic and periampullary carcinoma, we evaluated the frequency and the potential prognostic impact of the preoperative presence of DTC, defined as cytokeratin-positive cells detected by immunocytochemistry (ICC).

Methods

Preoperative BM samples from 242 patients selected for surgical resection of presumed resectable pancreatic and periampullary carcinoma from 09/2009 to 12/2014, were analysed for presence of CK-positive cells by ICC. The median observation time was 21.5 months. Overall survival (OS) and disease-free survival (DFS) were calculated by Kaplan-Meier and Cox regression analysis.

Results

Successful resections of malignant tumours were performed in 179 of the cases, 30 patients resected had benign pancreatic disease based on postoperative histology, and 33 were deemed inoperable intraoperatively due to advanced disease. Overall survival for patients with resected carcinoma was 21.1 months (95% CI: 18.0–24.1), for those with benign disease OS was 101 months (95% CI: 69.4–132) and for those with advanced disease OS was 8.8 months (95% CI: 4.3–13.3). The proportion of patients with detected CK-positive cells was 6/168 (3.6%) in resected malignant cases, 2/31 (6.5%) in advanced disease and 4/29 (13.8%) in benign disease. The presence of CK-positive cells was not correlated to OS or DFS, neither in the entire cohort nor in the subgroup negative for circulating tumour cells (CTC).

Conclusions

The results indicate that CK-positive cells may be present in both patients with malignant and benign diseases of the pancreas. Detection of CK-positive cells was not associated with differences in prognosis for the entire cohort or any of the subgroups analysed.

Trial registration

clinicaltrials.gov (NCT01919151).

Critical assessment of staining properties of a new visualization technology: a novel, rapid and powerful immunohistochemical detection approach

Immunohistochemical staining of tissue sections is a vital technique in pathological diagnostics and theranostics. Several kinds of detection systems are available—each of them with their advantages and disadvantages. Here we present the results of a study assessing a prototype immunohistochemical detection technology (PIDT) for visualization of antigens in tissue sections. Different tumor tissues (n = 11) were stained with selected antibodies (n = 30) and a subset of these under different fixation conditions. The staining properties were assessed according to six staining quality parameters (signal distribution, intensity, tissue and slide background, acutance, clarity of details, and subcellular morphological details), and the results were compared with those of a well-established detection system (EnVision FLEX). Overall, both detection methods revealed good to optimal results regarding the evaluated parameters even under unfavorable fixation conditions. However, with the prototype detection technology a quicker turnaround time was reached primarily due to shorter primary antibody incubation times. Moreover, PIDT-stained tissues showed higher signal intensity and a uniform signal distribution over the tissue slide, still, with well-preserved tissue morphology and without impairing the gradation of staining intensity of different cell types. In particular, the prototype detection technology performed better in poorly or delayed fixed tissue. In situations where rapid and profound results are in demand, and particularly in the context of a small laboratory setting, this prototype detection technology could be a useful addition to the established detection systems.

Transforming growth factor-α expression in benign and malignant human prostatic disease

Investigation of biological variables in prostatic disease may not only prevent patients with a good prognosis being overtreated, but allow better selection of appropriate therapy, and may identify potential targets for novel therapies. This study investigates the growth factor transforming growth factor-α (TGFα) expression in benign and malignant prostatic biopsies using both radioimmunoassay and immunohistochemistry, considering its role in malignant epithelial transformation and as a prognostic indicator. Biochemical methods were less satisfactory than the more selective immunohistochemical methods, due to the heterogeneity of prostatic tissue. Seventy-one percent of benign biopsies (range 0-18.62ng/mg DNA) and 69% of malignant biopsies (range 0-11.1ng/mg DNA) had detectable levels of TGFα using radioimmunoassay. Immunohistochemical staining for TGFaL identified expression in 15% of benign (4 out of 27) and 53% malignant biopsies (18 out of 34). Positive staining was also identified in premalignant lesions and within stromal elements, thus implying the factor's role in autocrine/paracrine growth and/or malignant transformation. Immunostaining for TGFα may enhance detection of premalignant lesions and small foci of malignant glands which are otherwise difficult to identify using standard histopathological techniques.

Effects of copper-impregnated collagen implants on local pro- and anti-inflammatory and regenerative tissue reactions following implantation in rats

Combining collagen, an established regenerative biomaterial, and copper (Cu) with its known antibacterial and angiogenic effects could improve wound healing. However, Cu is also cytotoxic. Thus, this study aimed at examining the tissue reactions after simultaneous intramuscular implantation of collagen discs either without Cu (controls) or impregnated in 2, 20, or 200 mmol/L Cu acetate in 24 rats. After 7, 14, and 56 days, implants with peri-implant tissue were retrieved from 8 rats/day for immunohistochemical detection of CD68⁺ monocytes/macrophages and CD163⁺ macrophages, MHC-II⁺ cells, T lymphocytes and nestin as tissue regeneration marker. CD68⁺ monocytes/macrophages around implants increased with Cu amount but decreased over time except for the highest Cu amount, while CD163⁺ macrophages increased over time around and within implants. MHC-II⁺ cells were similar to CD68⁺ monocytes/macrophages. T lymphocyte numbers around implants were higher for Cu-impregnated samples vs. controls on day 7 and highest on day 14, but declined afterwards. Nestin expression around and within implants was largely unaffected by Cu. In conclusion, pro-inflammatory reactions around implants were dose-dependently influenced by Cu but mostly decreased over time, while Cu did not negatively affect anti-inflammatory and regenerative reactions. These results suggest that Cu-impregnated collagen could be beneficial in wound treatment.

PTEN Expression in Prostate Cancer: Relationship With Clinicopathologic Features and Multiparametric MRI Findings

OBJECTIVE. The objective of our study was to investigate whether phosphatase and tensin homolog (PTEN) expression is associated with clinicopathologic features and multiparametric MRI findings in prostate cancer. MATERIALS AND METHODS. Forty-three patients with prostate cancer who underwent radical prostatectomy were included. Index tumor was identified on pretreatment MRI and delineated in the area that correlated best with histopathology results. The apparent diffusion coefficient (ADC) from DWI and pharmacokinetic parameters derived from dynamic contrast-enhanced MRI (DCE-MRI) using the extended Tofts model (K^trans, k_ep, v_e, and v_p) within the tumor were estimated. The following clinicopathologic parameters were assessed: pretreatment serum levels of prostate-specific antigen, disseminated tumor cell status, age, Gleason score, tumor size, extraprostatic extension (EPE), tumor location, and lymph node metastases. Gene expression profiles were acquired in biopsies from the tumor using bead arrays, and validated using reverse transcription quantitative polymerase chain reaction (RT-qPCR) on a different part of the biopsy. RESULTS. Based on bead arrays (p = 0.006) and RT-qPCR (p = 0.03) data, a significantly lower ADC was found in tumors with low PTEN expression. Moreover, PTEN expression was negatively associated with lymph node metastases (bead arrays, p = 0.008; RT-qPCR, p < 0.001). A weak but significant association between PTEN expression, EPE (p = 0.048), and Gleason score (p = 0.028) was revealed on bead arrays. ADC was negatively correlated with Gleason score (p = 0.001) and tumor size (p = 0.023). No association among DCE parameters, PTEN expression, and clinicopathologic features was found. CONCLUSION. ADC derived from DWI may be useful in selecting patients with potentially aggressive tumor caused by PTEN deficiency.

Gains and Losses of HLA Class II (DR) and CD4 in Atypical Hyperplasia, Carcinoma in situ and Infiltrating Ductal Carcinoma of the Breast

Aim: Breast cancer is a frequent cause of death among women with gynaecologic malignancies despite the introduction of combination chemotherapy. There is therefore a need for new therapeutic strategies for patients with breast cancer, such as cellular immunotherapy. In this immunohistochemical study we analyzed the epithelial expression of major histocompatibility complex (MHC) class II (HLA-DR) on atypical and malignant primary mammary epithelial cells, as well as the magnitude of the stromal T lymphocytes (T4 subset) at the tumor site. Experimental design: The study was carried out retrospectively in tumor tissue from 82 patients with mammary lesions (31 cases of atypical ductal hyperplasia -ADH-, 12 cases of ductal carcinoma in situ –DCIS- and 39 cases of infiltrating ductal carcinoma not otherwise specified -IDC-NOS). Medullary carcinomas were not included in our investigation. Material used had been formalin fixed and paraffin embedded. Results: HLA class II (DR) was expressed in 20 of 31 ADHs (64.5%), in 4 of 12 DCISs (33.3%), and in 10 of 39 IDC-NOSs (25.6%). CD4 was expressed in 9 of 31 ADHs (29%), in 5 of 12 DCISs (42%), and in 26 of 39 IDCNOSs (67%). Conclusions: The results showed decreased epithelial expression of HLA class II (DR) and increased stromal expression of CD4, as the lesion progressed to malignancy. Gradual loss of epithelial HLA class II expression might be a manifestation of cellular differentiation from the atypical form versus the malignant one, signaling simultaneously a selective effect on the response capacity of the immune system.

Immunohistochemical expression and prognostic role of CD10, CD271 and Nestin in primary and recurrent cutaneous melanoma

BACKGROUND

CD10, CD271 and Nestin, which are proteins associated with tumor-initiating properties and/or progression potential, have not been specifically studied on malignant melanoma (MM) with cutaneous recurrences.

METHODS

We evaluated the expression of CD10, CD271 and Nestin in 27 tumor samples from 16 patients. These tumor samples corresponded to 6 primary melanomas which developed 11 ITM and 10 primary melanomas without recurrences at 10-year follow-up from specimens obtained from surgical excisions of patients referred to the Unit of Dermatology, Department of Medical-Surgical and Transplant Physiopathology, University of Milan, between 2006 and 2016.

RESULTS

We demonstrated a higher expression of CD271 and Nestin in primary tumors which recurred than control population, Nestin was expressed with significantly higher percentages in primary tumors than recurrences, and CD10 expression was statistically significant correlated with disease-free survival: cases with a lower score recurred lately than cases with higher scores.

CONCLUSIONS

Our preliminary results suggested that CD271 and Nestin can be considered early biomarkers for the development of ITM, Nesting can be useful in differentiating primary MM from cutaneous recurrences and CD10 is associated with a rapid disease progression and may be considered a potential prognostic marker.

The congenital clubfoot - immunohistological analysis of the extracellular matrix

Purpose

Congenital clubfoot is one of the most common limb disorders in humans and its etiology is still unclear. In order to better understand the pathogenesis of patients with primary clubfoot, we examined whether there are quantitative changes in the extracellular matrix (ECM; based on common interstitial collagens [C] like CI and CIII, microfilamentous collagens like CVI, noncollagenous proteins like undulin, and enzymes like matrixmetalloproteinase [MMP]-2 and tissue inhibitor of matrixmetalloproteinase [TIMP]-2 that are known to play a role in fibrogenesis and fibrolysis) of muscles involved in the foot deformity of patients with primary clubfoot corresponding to fibrosis.

Patients and methods

Thirty patients (age ranging from 4 months to 5 years and 7 months) with primary clubfoot were examined (23 male and 7 female patients), among whom 18 patients were affected on one side and 12 affected on both sides. Twenty-five biopsies were taken during the first operative foot correction (Crawford-McKay) and 5 in the context of relapses. Muscle biopsies were taken from the muscles involved in the defect (Musculus [M.] gastrocnemius and M. tibialis anterior) and from the M. vastus lateralis of the M. quadriceps femoris, which were treated as healthy comparison muscles. Quantitative analysis of the components of the ECM was performed using a computer-assisted fibrosis measurement of the immunohistochemically processed tissue samples.

Results

We found higher values for M. gastrocnemius for CI, CIII, CVI and undulin in comparison with M. vastus lateralis. However, values for TIMP-2 were reduced. We found no significant differences for the components of M. tibialis anterior and M. vastus lateralis. There were no quantitative differences between male and female or between patients affected on one side and both sides. In patients who underwent relapse surgery, CI, CIII, CVI, and undulin of the gastrocnemius were significantly higher, while TIMP-2 was significantly lower.

Conclusion

In the present study, we found manifest fibrosis in gastrocnemius due to quantitative changes in the ECM. In contrast to other studies, we found increasing fibrosis not just in contracted tissues but also in the muscle itself. Further studies are needed to clarify whether these changes are primarily responsible for the malfunction or whether they occur secondarily in the consequence of the dysfunction.

Immunohistochemistry in Investigative and Toxicologic Pathology

Immunohistochemistry (IHC) is a valuable tool in pathology. This review provides a brief description of the technical aspects of IHC and a detailed discussion on the variables that affect the results, interpretation, and reproducibility of IHC results. Lists of antibodies that have and have not worked in IHC on various mouse and rat tissues in our laboratory are provided as a guidance for selection of antibodies. An approach to IHC method optimization is presented. Finally, the critical information that should be included as a part of peer-reviewed manuscript is also discussed.

Granulocytic Sarcoma with Myxoid Stroma. Report of a Case

A granulocytic sarcoma with myxoid features simulating a chondrosarcoma was detected in the left arm of a 59 years old man. It is suggested that extramedullary hematopoietic neoplasms such as granulocytic sarcoma may display, similarly to malignant lymphomas, non-specific sarcoma-like features that obscure the usual diagnostic characteristics.

Establishment of a Human Medulloblastoma Cell Line (Bo-101) Demonstrating Skeletal Muscle Differentiation

A permanent cell line, BO-101, was derived from a classic vermian medulloblastoma in a 9-year-old child. This line grew in vitro in adherent cultures and grew in athymic mice as serially transplantable intracranial and subcutaneous xenografts. Intracranial neoplasms grew as masses of small cells, which focally showed large cells with intense immunoreactivity for desmin, myoglobin and α-striated actin. The rhabdomyoblastic nature of these cells was confirmed ultrastructurally. The primary neoplasm showed immunoreactivity for synaptophysin, neuron-specific enolase and vimentin. A large panel of monoclonal antibodies and antisera against neuronal and glial antigens failed to show glial and neuronal immunoreactivity in the cell culture and xenografts. Despite the marked genotypic and phenotypic differences, the original neoplasm and the cell line share a common chromosomal marker del (12) (p 13.1). The BO-101 line differs phenotypically and genotypically from previously established medulloblastoma cell lines and further supports the heterogeneous biologic proprieties of the cell populations that constitute these neoplasms.

Central Neurocytoma. A Clinico-Pathologic study of Five Cases

Five cases of central neurocytomas are described. The tumors occurred in relatively young patients (range 14 to 43 years; mean age, 27) with no predilection for sex. All the lesions were located in the anterior portion of the lateral ventricles or in the third ventricle, involving the septum pellucidum or the fornix. Histologically, they were composed of uniform cells with round nuclei and clear cytoplasm resembling oligodendrogliomas or, to a lesser extent, ependymomas. In 4 tumors, protein cell nuclear antigen immunostaining showed a low cell proliferation rate. All cases were positive for neuron-specific enolase. Four of the 5 cases were strongly immunoreactive for synaptophysin. The immunohistochemical data were consistent with neuronal differentiation. Resection was subtotal in 4 cases and total in one. Postoperative radiotherapy was given in only one case. The follow-up revealed a good prognosis: 4 patients were alive and had a long survival (from 2 to 8 years). Only one patient died after 14 months for causes unrelated to the neoplasm. The authors emphasize the importance of immunohistochemistry to recognize this benign intraventricular tumor.

Granular Cell Tumor: An Immunohistochemical Study

Aims and background

Granular cell tumor, usually a benign neoplasm, has been the object of many studies because of its uncertain histogenesis and based on many immunohistochemical and ultrastructural studies it has been suggested that it originates from the Schwann cell. Our recent observation that granular cell tumor is positive with PG-M1, a new anti-macrophage monoclonal antibody, led us to further investigate the immunophenotypic profile of the tumor.

Study design

We studied 11 granular cell tumors using a panel of 20 antibodies, 13 monoclonal and 7 polyclonal.

Results

The immunohistochemical study showed in all cases a constant diffuse positivity for S-100 protein, neuron-specific enolase, vimentin, KP1 and PG-M1, as well as occasional and focal positivity for alpha-1-antitrypsin, alpha-1-antichymotrypsin and lysozyme.

Conclusions

The immunophenotypic profile constantly observed could be the expression, on one hand, of the neuroectodermic nature of the neoplasm, proven by positivity for S-100 protein, neuron specific enolase and vimentin, and on the other could be the expression of the phagocytic activity of the tumor cell, proven by positivity for KP1 and PG-M1 antibodies and also by the presence of numerous phagolysosomes.

An Efficient Method for Culturing Human Breast Epithelium: Analysis of Results

We have examined the possibility of obtaining primary cultures from breast tissue utilizing a method especially developed for breast epithelium. The number of specimens able to grow in culture was very high: 82.8%, 64.3 %, 75.0 % and 77.8 %, respectively, for primary breast cancer, skin recurrences, inflammatory breast cancer and normal breast tissue. In our experience, growth was not related to menopausal status or histopathologic type, whereas for skin recurrences, a prior pharmacologic treatment (chemotherapy) of the patient enhanced the growth capacity of the tissue. This culture method could help to study the basic biology of breast epithelia and to improve the chemotherapy approach of breast cancer patients.

Giant Cell Tumor of Bone: A Model for the in Vitro Human Osteoclast Characterization

The in vitro growth pattern of cells obtained from bioptic material of ten patients with giant cell tumor of bone (GCT) was investigated. Cytochemical reactions and monoclonal antibodies raised against macrophage markers were tested on the two histologically identifiable GCT cell populations. Only monoclonal antibody EBM/11 stained both mononuclear and giant cells. EBM/11 positivity and resistance of acid phosphatase to high doses of tartrate strongly suggest that both mononuclear and giant cells belong to the same lineage.

Conjunctival Fibrosis after Application of Mitomycin C: An Animal Experimental Study

Mitomycin C (MMC) is widely used as an antimetabolite to minimize scarring of filtering blebs. Its effectiveness has been demonstrated in several clinical studies. The drug's mechanism of action is attributed to its antiproliferative effect on the subconjunctival cells, reducing the wound healing response. We placed sponges soaked with various concentrations of MMC, from 0.05 to 1.0 mg/ml, under the conjunctiva of 18 rabbits. Four weeks later, there was marked concentration-dependent scarring of the substantia proppria of the conjunctiva. Macrophages were more numerous in treated eyes, as determined by immunohistochemistry. The reason for MMC-related fibrosis in this animal model is not clear but may be related to the substances toxic effects. Whether it is only present in rabbits remains to be clarified.

Burkitt-Like Lymphoid Malignancy Presenting as a Breast Tumor

The authors describe a case of a female patient, who presented with a rapidly expanding mass of the right breast as the first clinical sign of a Burkitt-like lymphoproliferative disorder. Massive bone marrow infiltration with leukemic spillover and limited lymph node involvement were subsequently detected. The difficulties encountered in classifying, according to current schemes, the observed lymphoid neoplasm are emphasized. Moreover, an evaluation of the true rarity of mammary localizations at the onset of lymphoid malignancies, based on a review of the literature, suggests, especially for the most malignant varieties, a higher frequency than supposed.

Progenitor Cells Purging: Negative Selection

Disease relapse after autologous bone marrow transplantation (ABMT) may arise from residual tumor in the recipient and/or from cancer cells that are reinfused. The aim of purging by negative selection is to remove tumor cells from the marrow without adversely affecting the engraftment potential of the normal cell. We report the results of a study on fifty-six patients (pts) with non Hodgkin's lymphoma or acute leukemia submitted to ABMT after immunomagnetobead (1MB) purging (11 pts), Maphosphamide purging (31 pts) and no purging (14 pts). The 1MB procedure involved one incubation of 3 monoclonal antibodies (CD10, CD19 and CD22) and two incubations with magnetic beads (Dynabeads M-450). The median recovery of mononuclear cells and CFU-GM was 40% and 45% after IMB purging and 84% and 5% after Maphosphamide purging respectively. The rate of leukocyte, neutrophils and platelets recovery following ABMT was similar in the three groups of pts, although platelet recovery was slow in patients received graft purged with Maphosphamide. Our study confirms the clinical feasibility of the IMB procedure, but only randomized studies will be able to definitibely address the question of the clinical utility of purging.

Experimental Vitreous Replacement with Perfluorophenanthrene

PURPOSE

We studied the toxicity of perfluorophenanthrene (PFP), used as short-, medium-, or long-term internal tamponading substance, on the rabbit choroid and retina. The aim was the check whether PFP is tolerated as a tamponade in the eye or damages the retina, and if any such damage is due to toxicity or to emulsification which may stimulate phagocytosis.

METHODS

Twenty-four right eyes of rabbits operated by vitrectomy were filled with 0.8-1 ml of PFP as retinal tamponading substance. Twelve eyes were operated by vitrectomy and filled with 0.8-1 ml of balanced salt solution as the control group. Direct and indirect ophthalmoscopy was done on the third and seventh day after surgery, then once a week. Enucleation, with histological and immunohistochemical examination, was done on the second day, then in the first, second, fourth and eighth weeks after surgery.

RESULTS AND CONCLUSIONS

Histological examination showed progressive damage of the chorioretinal tissues right from the second week: the chorioretinal structure was completely altered from the eighth week. Immunohistochemical examinations showed that glia cells were involved in the inflammation consequent to internal tamponade with PFP.

Detection of a Soluble form of the Receptor for Interleukin 2 in the Serum of Patients with Hairy Cell Leukaemia

The sera of patients with hairy cell leukaemia (HCL) contain a factor which inhibits the binding of anti-IL-2R antibody to its target (activated T lymphocytes). The presence of this factor, which probably corresponds to the soluble form of IL-2R (sIL-2R), can be easily detected using a simple immunocytochemical inhibition assay. In a series of patients with chronic lymphoproliferative diseases the presence of sIL-2R appeared to be specific for HCL, using the sensitivity of our test, since it could not be detected in sera from normal subjects and patients with B-cell lymphocytic leukaemia or Hodgkin's disease. Thus it might be used as an additional tool for characterizing HCL patients.

Methods of Simultaneous Visualization of Cytoplasmic Enzyme Reactivity and Cell Surface Antigens (by Cytochemistry Combined with Immunocytochemistry) in Individual Hematopoietic and Lymphoid Cells

Enzyme cytochemistry alone, and more recently, immunocytohistochemistry have been satisfactorily used by hematologists and hematopathologists for the study, diagnosis and classification of human hematological and lymphoproliferative disorders. To enhance the potential of these techniques, the possibility of combining immunocytohistochemical techniques with enzyme cytohistochemistry with simultaneous visualization of both reaction products has been examined by some investigators. This approach has been applied to normal, reactive and neoplastic material using mainly cell suspensions and frozen sections, with the aim of improving cell identification in specimens containing different cell types, of determining the cytochemical profiles of well-defined lymphocyte subpopulations and of establishing the cell surface phe-notypes of cells that are positive for certain enzymes. In this paper, published reports on this subject are reviewed and compared with the experience of our study group.

Local Impairment of Immunoreactivity in Hiv-infected Women with Hpv-related Squamous Intraepithelial Lesions of the Cervix

Aims and background

The aim of this study was to compare the local immune response in two groups of patients with high-grade cervical intraepithelial squamous lesions (SIL): one with HIV infection and the other with HPV infection alone.

Materials and methods

16 conization specimens (8 from HIV-infected and 8 from non-HIV-infected patients) of HPV-related, high-grade SIL were selected. The specimens from non-HIV patients were considered as controls. The total number of Langerhans cells, CD4 and CD8 cells present in 10 field areas (3.120 mm2) was recorded in each case. In HIV patients CD4 and CD8 peripheral counts were performed immediately before surgery.

Results

The CD4/CD8 ratio never exceeded 0.71, whereas the lowest ratio in controls was 0.81: this difference was statistically significant (P=0.0009). The mean number of Langerhans cells was markedly reduced in the high-grade SILs in the HIV patients in comparison with controls (P=0.001). The number of CD4 cells and the CD4/CD8 ratio correlated with the peripheral CD4 count (P=0.001 and 0.02).

Conclusions

In our study a marked local impairment of cervical immunoreactivity was observed, which may play a major role in the progression of these lesions in HIV-infected women.

Giant Cell Tumor of Tendon Sheath: Immunohistochemical Study of 20 Cases

Aims and background

Giant cell tumor of tendon sheath (GCTTS) is a common tumor occurring on the tendon sheaths of the fingers. The nature of this lesion is still controversial: some researchers consider it a reactive process arising from chronic inflammation while others regard it as a tumor of presumed synovial cell or monocytic macrophage system origin. In an effort to clarify the histogenesis we decided to further investigate the immunophenotypic profile of this tumor.

Study design

We studied 20 GCTTS of the fingers using a panel of 18 antibodies, 13 monoclonal and 5 polyclonal.

Results

The immunohistochemical investigation revealed that the mononuclear cells of this lesion can be divided into two groups. The cells of the first and more numerous group were positive for vimentin, PG-M1 and KP1 but also for muscle actin (HHF35 monoclonal antibody) and neuron-specific enolase. A second population of mononuclear cells, usually arranged around the giant cells, were positive for PG-M1, KP1, LCA and occasionally for alpha-1-antitrypsin and alpha-1-antichymotrypsin. Multinucleated giant cells were also positive for KP1, PG-M1 and LCA monoclonal antibodies. A variable but usually weak positivity for al-pha-1-antitrypsin, alpha-1-antichymotrypsin and lysozyme was also observed.

Conclusions

Our results suggest a synovial cell origin for GCTTS and do not support the hypothesis that it could be a neoplasm with a true histiocytic origin. The positivity of some cells for the HHF35 antibody, together with electron microscopic evidence of filament bundles with focal dense bodies, suggests that at least part of the mononuclear cells may have a myofibroblastic differentiation.

Expression of the Tumor-Associated Glycoproteins Mca, Ca 125 and Bw 495/36-P in Epithelial Tumors of the Kidney and the Urinary Bladder

The differential expression of the tumor-associated glycoproteins MCA, CA 125 and BW 495/36-P was investigated in 11 renal cell carcinomas and 11 urinary bladder carcinomas and compared with their expression in non-neoplastic tissue preparations from the kidney (n = 9) and urinary bladder (n = 12). The glycoproteins were demonstrated immunohistologically in frozen sections and additionally, in some cases, in paraffin sections. MCA and BW 495/36-P positive cells were present in all preparations except for a grade I transitional cell carcinoma of the bladder, in which no MCA-expression could be detected. In the non-neoplastic renal tissue mainly the cells of the distal tubuli were stained by the antibodies against these two glycoproteins. Carcinoma cells of the kidney and of the urinary bladder showed an increased expression of both epitopes.

CA 125, in comparison, was strongly expressed in 3 of the 11 urinary bladder carcinomas investigated but could only be shown in a few cells of a single renal cell carcinoma. Normal renal tissue showed no and the urinary bladder only very isolated CA 125 positive epithelial cells. Apart from this distribution, strong staining of the connective tissue fibers with CA 125 antibody was seen in all paraffin sections, but not in the frozen sections. This leads to the supposition that in these structures there is a CA 125 cryptantigen. The consistent expression of MCA as well as the virtual lack of CA 125 in the renal cell carcinomas are in contrast with our previous serological results, in which patients with metastatic renal cell carcinomas showed increased CA 125 in approx. 50% of cases whereas only approx. 20% had increased MCA serum levels.

Ki-67 Antibody Immunostaining in Benign and Malignant Human Prostatic Disease

Indices of mitotic potential may improve prognostic discrimination in patients with malignant disease. Ki-67 is a monoclonal antibody directed against an unknown proliferation antigen which has been shown to be a measure of mitotic potential. Sixty-four benign and eighty malignant prostatic biopsies were stained with the Ki-67 antibody. Nuclear and cytoplasmic staining was identified in benign and malignant biopsies using immunoalkaline phosphatase and immunoperoxidase staining reactions. Nuclear staining was identified in 14 benign and 44 malignant biopsies. Nuclear staining for Ki-67 was seen in 36% of biopsies with Gleason histological score (GHS) 2-4, 71% with GHS 5-7 and 62%> with GHS 8-10. Nuclear staining was associated with advanced local disease stage, but not with metastatic disease stage. Clinical follow-up is required to establish the value of Ki-67 immunostaining as a prognostic determinant in prostatic cancer.

Immunocytochemical determination of the tumor-associated glycoproteins MCA, CA 125 and BW 495/36-P in urine of patients with epithelial tumors of the kidney and urinary bladder

Pre-operative and, in some cases, post-operative urine samples from 29 patients with renal cell or urinary bladder carcinoma were compared to samples from 24 healthy persons and 10 patients with nephrolithiasis and 9 patients with other benign disorders of the efferent urinary tract. The specimens were examined for the presence of MCA, CA 125 and BW 495/36-P expressing epithelial cells. The urine concentrations of the soluble antigens MCA and CA 125 were determined simultaneously in urine samples from 35 patients with renal cell or urinary bladder carcinoma, 10 patients with cystitis and 30 healthy individuals.

MCA and BW 495/36-P expressing epithelial cells were significantly increased in all pre-operative urine samples of the tumor patients compared to the group of healthy persons. This increase was also seen with CA 125-positive cells in patients with bladder carcinoma, not however in patients with renal cell carcinoma. BW 495/36-P positive cells were also found in both groups of tumor patients in greater numbers than in the patients with nephrolithiasis or other benign urinary tract disorders. Based on a specificity of 97% when compared to the control urine samples, the cytological determination of the antigens MCA, CA 125 and BW 495/36-P in urinary tract cells of all tumor patients revealed a sensitivity of 48%, 33% and 79% as well as a positive predictive value of 92%, 89% and 95%, respectively. The sensitivity of CA 125 increased to 67% upon isolated analysis of patients with bladder carcinoma.

The majority of labelled cells were not identifiable as tumor cells morphologically and appeared as normal transitional epithelial cells.

The urinary concentration of soluble MCA was greatest in healthy patients whereas the concentration of CA 125 was increased in patients with bladder carcinoma.

Our results indicate that especially the determination of BW 495/36-P expressing epithelial cells could be a helpful supplement to the cytological examination of urinary epithelium with regard to renal cell and bladder carcinoma. Determination of CA 125-positive cells appears to be of diagnostic relevance only in cases of suspected bladder carcinoma.

Effect of Glycine, Pyruvate, and Resveratrol on the Regeneration Process of Postischemic Intestinal Mucosa

Background

Intestinal ischemia is often caused by a malperfusion of the upper mesenteric artery. Since the intestinal mucosa is one of the most rapidly proliferating organs in human body, this tissue can partly regenerate itself after the onset of ischemia and reperfusion (I/R). Therefore, we investigated whether glycine, sodium pyruvate, and resveratrol can either support or potentially harm regeneration when applied therapeutically after reperfusion injury.

Methods

I/R of the small intestine was initiated by occluding and reopening the upper mesenteric artery in rats. After 60 min of ischemia and 300 min of reperfusion, glycine, sodium pyruvate, or resveratrol was administered intravenously. Small intestine regeneration was analyzed regarding tissue damage, activity of saccharase, and Ki-67 positive cells. Additionally, systemic parameters and metabolic ones were obtained at selected periods.

Results

Resveratrol failed in improving the outcome after I/R, while glycine showed a partial beneficial effect. Sodium pyruvate ameliorated metabolic acidosis, diminished histopathologic tissue injury, and increased cell proliferation in the small intestine.

Conclusion

While glycine could improve in part regeneration but not proliferation, sodium pyruvate seems to be a possible therapeutic agent to facilitate proliferation and to support mucosal regeneration after I/R injury to the small intestine.

Human monocytes downregulate innate response receptors following exposure to the microbial metabolite n-butyrate

Introduction

Hyporesponsiveness of human lamina propria immune cells to microbial and nutritional antigens represents one important feature of intestinal homeostasis. It is at least partially mediated by low expression of the innate response receptors CD11b, CD14, CD16 as well as the cystine‐glutamate transporter xCT on these cells. Milieu‐specific mechanisms leading to the down‐regulation of these receptors on circulating monocytes, the precursor cells of resident macrophages, are mostly unknown.

Methods

Here, we addressed the question whether the short chain fatty acid n‐butyrate, a fermentation product of the mammalian gut microbiota exhibiting histone deacetylase inhibitory activity, is able to modulate expression of these receptors in human circulating monocytes.

Results

Exposure to n‐butyrate resulted in the downregulation of CD11b, CD14, as well as CD16 surface expression on circulating monocytes. XCT transcript levels in circulating monocytes were also reduced following exposure to n‐butyrate. Importantly, treatment resulted in the downregulation of protein and gene expression of the transcription factor PU.1, which was shown to be at least partially required for the expression of CD16 in circulating monocytes. PU.1 expression in resident macrophages in situ was observed to be substantially lower in healthy when compared to inflamed colonic mucosa.

Conclusions

In summary, the intestinal microbiota may support symbiosis with the human host organism by n‐butyrate mediated downregulation of protein and gene expression of innate response receptors as well as xCT on circulating monocytes following recruitment to the lamina propria. Downregulation of CD16 gene expression may at least partially be caused at the transcriptional level by the n‐butyrate mediated decrease in expression of the transcription factor PU.1 in circulating monocytes.

Allogeneic Hepatocyte Transplantation Using FK 506

Hepatocyte transplantation is an intriguing alternative to orthotopic liver transplantation. While engraftment of syngeneic hepatocytes can be achieved with relative ease, engraftment of allogeneic hepatocytes has been far more complicated. We used FK 506 (Tacrolimus), a novel and highly efficient immunosuppressant, which has been reported to augment liver regeneration in rats. Recipients of isolated syngeneic (LEW) and allogeneic (Wistar F.) rat hepatocytes (major histocompatibility barrier) recieved different immunosuppressive regiments with FK 506 or Cyclosporine A (CsA). Mature syngeneic hepatocytes could be retrieved up to post op day 300 with the lowest number of hepatocytes on post op day 20. Following allogeneic transplantation, no mature hepatocytes could be identified after post op day 10, though ductular like structures within the spleen were found in FK 506 but not CsA-treated animals. The epithelial cells of ductular like structures exhibit cytological features of CK-19 positive cells. Our results suggest that under CsA or FK 506 immunosuppression long-term survival of mature allogeneic hepatocytes within the spleen cannot be achieved across a major histocompatibility barrier though FK 506 allows engraftment of allogeneic donor type ductular cells. Copyright © 1997 Elsevier Science Inc.

NG2 proteoglycan as a pericyte target for anticancer therapy by tumor vessel infarction with retargeted tissue factor

tTF-TAA and tTF-LTL are fusion proteins consisting of the extracellular domain of tissue factor (TF) and the peptides TAASGVRSMH and LTLRWVGLMS, respectively. These peptides represent ligands of NG2, a surface proteoglycan expressed on angiogenic pericytes and some tumor cells. Here we have expressed the model compound tTF-NGR, tTF-TAA, and tTF-LTL with different lengths in the TF domain in E. coli and used these fusion proteins for functional studies in anticancer therapy. We aimed to retarget TF to tumor vessels leading to tumor vessel infarction with two barriers of selectivity, a) the leaky endothelial lining in tumor vessels with the target NG2 being expressed on pericytes on the abluminal side of the endothelial cell barrier and b) the preferential expression of NG2 on angiogenic vessels such as in tumors. Chromatography-purified tTF-TAA showed identical Factor X (FX)-activating procoagulatory activity as the model compound tTF-NGR with Km values of approx. 0.15 nM in Michaelis-Menten kinetics. The procoagulatory activity of tTF-LTL varied with the chosen length of the TF part of the fusion protein. Flow cytometry revealed specific binding of tTF-TAA to NG2-expressing pericytes and tumor cells with low affinity and dissociation KD in the high nM range. In vivo and ex vivo fluorescence imaging of tumor xenograft-carrying animals and of the explanted tumors showed reduction of tumor blood flow upon tTF-TAA application. Therapeutic experiments showed a reproducible antitumor activity of tTF-TAA against NG2-expressing A549-tumor xenografts, however, with a rather small therapeutic window (active/toxic dose in mg/kg body weight).

Primary Choriocarcinoma of the Rectum in a Man Case Report and Literature Review

A case of pure extragonadal choriocarcinoma in the rectum of an 84-year-old man is described. The patient complained of rectal bleeding and lower abdominal pain. The trophoblastic origin of the tumor was documented by immunoperoxidase staining for human chorionic gonadotropin. The DNA histogram showed a diploid pattern. The patient died 106 days after diagnosis. Only eight cases of choriocarcinoma of the large intestine have been reported, three of which were located in the rectum. The age of patients affected range widely, from 28 to 84 years with a mean of 54 years: 79 for males and 46 for females. Women are affected three times as often as men. The pathologic study showed adenocarcinoma with germ cell elements in seven cases: six choriocarcinoma and one mixed (choriocarcinoma and endodermal sinus tumor). Germ cell differentiation may be difficult to identify in small biopsy samples, which may not be representative of the tumor as a whole. The prognosis of patients with choriocarcinoma of the large bowel is very poor; survival is less than 5 months. Although choriocarcinoma in the rectum is very rare, it should be included in the differential diagnosis of rectal neoplasms.

Basaloid Squamous Cell Carcinoma of the Esophagus Immunohistochemistry and Flow Cytometric DNA Analysis in Two Cases

Basaloid squamous cell carcinoma is a well-established anatomopathologic entity of the upper aerodigestive tract and is more aggressive than the conventional squamous cell carcinoma. Only seven cases of this variant have been reported in the esophagus. Two cases of basaloid squamous carcinoma in the middle and lower third of the esophagus in two men aged 59 and 60 years are presented. Tumor stages were IIA and IV at the time of total esophagectomy, and survival times were 34 and 4 months, respectively. Histologically, the two tumors were composed of nests of cells with a basaloid appearance, the first with a predominantly cribriform pattern and the second with a solid lobular pattern and intense comedonecrosis; in the adjacent squamous epithelium of both tumors, carcinoma in situ was observed focally. Immunoreactivity was poor for high-molecular-weight cytokeratins and absent for those of low molecular weight. Staining for epithelial membrane antigen was weakly positive, enolase was moderately positive, and no reactivity for carcinoembryonic antigen, S100 protein, and chromogranin was observed. The flow cytometric analysis showed both tumors to be hyperdiploid with an index of cell proliferation of over 50%.

CFTR Localization in Native Airway Cells and Cell Lines Expressing Wild-type or F508del-CFTR by a Panel of Different Antibodies

The intracellular localization of cystic fibrosis transmembrane conductance regulator (CFTR) in native tissues is a major issue in the study of mutation, processing, and trafficking effects in CFTR and in the evaluation of therapeutic strategies in cystic fibrosis (CF). This work evaluated the applicability of ten different antibodies (Abs) under various fixation techniques for CFTR localization in fresh-brushed nasal epithelial cells collected from CF patients homozygous for F508del and control individuals. In parallel, the same Ab panel was also tested on BHK cell lines overexpressing wild-type or F508del CFTR. The Abs MATG1061, 169, Lis1, MP-CT1, CC24-R, MAB25031, and MAB1660 gave the best detection of CFTR in the apical region (AR) of nasal tall columnar epithelial (TCE) cells. The labeling pattern of these Abs was consistent with the postulated processing defect of F508del CFTR because only a minority of CF TCE cells present CFTR in the AR. In contrast, M3A7, MM13–4, and L12B4 weakly react with the AR and stain almost exclusively a cis-Golgi-like structure in the majority of CF and non-CF airway cells. In BHK cells, all the Abs enabled distinction between wild-type CFTR localization in cell membrane from F508del CFTR, which in these cells is exclusively located in the endoplasmic reticulum.

Immunohistochemical Expression of Apoptotic Markers in Drug-Induced Erythema Multiforme, Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are considered to be severity variants of the same disease, which is almost always associated with drug intake. In contrast, erythema multiforme (EM) is a disorder regarded as only rarely caused by drugs. Keratinocyte apoptosis has been shown to play an important part in the pathogenesis of SJS and TEN, whilst its role in EM remains controversial. To determine the expression of apoptosis-associated molecules Fas, Fas ligand (FasL), Bcl-2 and Bax in the above disorders, an immunohistochemical analysis was performed. We studied both lesional skin from thirty patients having drug-induced EM and 5 cases classified within the SJS/TEN spectrum and normal skin samples. We found a keratinocyte overexpression of Fas antigen, an important molecule mediating apoptosis, not only in SJS and TEN but also in EM. Another noteworthy finding was the strong expression of Bcl-2, a protein known as blocking apoptosis, along the basal layer and in the dermal infiltrate both in SJS/TEN and in EM. Taken together, these findings suggest that Fas-dependent keratinocyte apoptosis may play a part in the pathogenesis of both SJS/TEN and EM. Fas-mediated cell death may be partially suppressed by the Bcl-2 protein.

IL-17, IL-23, and p73 expression in cutaneous melanoma: a pilot study

The incidence of cutaneous malignant melanoma is increasing worldwide, resulting in the demand for clinically useful prognostic biomarkers, especially for invasive and metastatic disease. We studied the immunohistochemical expression of interleukin-17 (IL-17), IL-23, and p73 in 35 malignant melanomas and compared them with benign melanocytic nevi and Spitz nevi, correlating them with clinical-pathological variables. A higher and statistically significant difference (P<0.05) in the intensity and percentage of stained cells of IL-17 and IL-23 was found in the melanoma group than in ordinary benign nevi that did not correlate with Breslow thickness nor Clark level. Moreover, p73 staining and percentage of stained cells was significantly higher (P<0.05) in all the melanomas studied, with a peculiar cytoplasmatic distribution. Our findings could suggest a possible IL-17, IL-23, and p73 involvement in cutaneous melanomas with a hypothetical impact on melanoma invasiveness.