Immunocytochemical differentiation of neoplastic and hyperplastic canine epithelial lesions in cytologic imprint preparations

Antigens under cover-The preservation and demasking of selected antigens for successful poststaining immunocytochemistry of effusion, brain smears, and lymph node aspirates

Background

In clinical cytology, the applicability of an ancillary test such as immunocytochemistry is too often limited by low sample volume, poor cell representation, and sample preservation. Diagnosticians often read Romanowsky‐stained cytology, although specific techniques such as immunocytochemistry are often essential for a definitive diagnosis.

Objectives

The goal of the present study aimed to investigate if immunocytochemistry on previously‐stained cytologic specimens was possible. Different pretreatments were examined to determine which treatment preserved antigenicity best.

Methods

One hundred and twenty‐two impression smears and 64 fine‐needle aspirate preparations of brain and lymph nodes were processed and evaluated microscopically. The impact of staining cytologic preparations with a modified Wright's stain, using a destaining method, performing a coverslipping and decoverslipping process, and subjecting smears to a microwave treatment (MWT) were examined for the immunolabeling of selected nuclear, cytoplasmic, and plasmalemmal antigens, as well as intracellular feline coronavirus (FCoV). Biotinylated secondary antibodies were used, and the bound primary antibody was visualized using an ABC amplification kit.

Results

Cellular antigens were reliably detected with immunocytochemistry after smears were stained with a Romansky stain and were coverslipped early after staining and stayed coverslipped until immediately before immunolabeling. The staining intensity reached the same levels as that of the controls if the films underwent MWT in citrate buffer. In contrast, FCoV antigen detection was abolished after any physicochemical interference.

Conclusions

Poststaining immunocytochemistry represents a practical tool for additional investigations on prestained cytologic specimens when searching for cellular antigens. Paired untreated samples should be kept in case the workup requires testing for more vulnerable viral antigens.

Cytological and immunocytological detection and differentiation of Marek's disease and lymphoid leucosis in poultry

Marek's disease (MD) and lymphoid leucosis (LL) are the major diseases causing lymphoid tumors in chickens accounting for high economical losses. Gross examination could not yield definite diagnosis owing to their similar presentation of lesions. Thus present work was aimed for diagnosis and differentiation of MD and LL by utilizing simple cytology and novel immunocytology techniques. Cytological examination was carried out on slides with tumor touch imprints stained by simple Giemsa staining. The diagnosis was mainly achieved based on morphology of cell population. In the present study, out of a total of 595 cases examined, 502 cases had pleomorphic lymphocytic cell population suggestive of MD and 53 cases had uniform lymphocytic/lymphoblast cell population suggestive of LL, while the rest 40 cases remained inconclusive. A definitive diagnosis was achieved after performing immunocytology using specific antibodies that revealed 518 cases had reactivity for Meq oncoprotein specific for MD and 77 cases showed immunoreactivity for IgM in transformed B-cells confirming LL. The technique of immunocytology which has been useful for detecting human viral pathogens and MD in poultry has been applied for the first time as a novel, simple, rapid and inexpensive technique that could be used as an alternate test to effectively detect and differentiate MD and LL in poultry.

Rapid multiple immunofluorescent staining for the simultaneous detection of cytokeratin and vimentin in the cytology of canine tumors

BACKGROUND

Immunocytochemistry (ICC) is utilized as an advanced technique in veterinary cytology. In tumor diagnosis, cytokeratin and vimentin are markers used to distinguish the origin of tumor cells. Standard enzyme-based ICC has limitations in clinical use; and therefore, more convenient and reliable methods are needed.

OBJECTIVES

The purpose of this study was to develop a rapid multiple immunofluorescent (RMIF) detection method for dual cytokeratin and vimentin staining on cytology slides in dogs.

METHODS

Air-dried smear samples from solid tumors and sediments of pleural effusions were prepared from dogs (n = 14) that were admitted to the Veterinary Teaching Hospital, Kagoshima University, Japan. Mouse monoclonal anti-human cytokeratin (AE1/AE3) and rabbit monoclonal anti-human vimentin (SP20) antibodies were used as primary antibodies, followed by staining with Alexa Fluor-conjugated secondary antibodies. Staining using the RMIF method was compared with enzyme-based ICC staining.

RESULTS

Rapid multiple immunofluorescent immunostaining was clear and specific in the evaluated smears, whereas the enzyme-based ICC showed nonspecific signals. By using the RMIF staining method, epithelial cells, mesenchymal cells, and mesothelial cells could be classified on a single smear of a pleural effusion. In smears of lymph nodes with epithelial tumor metastases, the RMIF method successfully detected metastatic epithelial tumor cells.

CONCLUSIONS

The RMIF method might be a useful tool for diagnostic cytology in veterinary medicine.

Coordinate expression of cytokeratins 7 and 14, vimentin, and Bcl-2 in canine cutaneous epithelial tumors and cysts

Forty-seven canine cutaneous epithelial tumors and cysts were examined to determine coordinate expression of cytokeratins 7 (CK7) and 14 (CK14), vimentin, and Bcl-2 using commercially available antibodies. Within non-affected normal skin adjacent to tumors or cysts, CK7 expression was observed in luminal cells in apocrine glands; CK14 expression was observed in the stratum basale, stratum spinosum, stratum granulosum, basal layer of outer root sheath, sebaceous glands, and myoepithelial cells of apocrine glands; vimentin expression was observed in dermal papilla and scattered non-epithelial cells within the epidermis; and Bcl-2 expression was observed in scattered non-epithelial cells in the epidermis and some apocrine glands. The pattern of expression of CK7 and CK14 in cases of adenocarcinoma of the apocrine gland of the anal sac (CK7+/CK14-) and hepatoid gland tumors (CK7-/CK14+) may prove useful for diagnostic purposes. Loss of expression of CK14 and vimentin, identifying myoepithelial cells, was observed in apocrine and ceruminous adenocarcinomas. Differences in patterns of expression of Bcl-2 were observed between infundibular keratinizing acanthomas compared to trichoepitheliomas.

Visfatin: an adipokine activator of rat hepatic stellate cells

The present study was conducted to investigate the effects of visfatin on the activation of hepatic stellate cells (HSC) and the possible underlying mechanism. HSC were isolated from the livers of Sprague‑Dawley rats by in situ perfusion of collagenase and pronase and a single‑step density Nycodenz gradient. The culture‑activated cells were serum‑starved and incubated with different concentrations of recombinant visfatin (0, 25, 50, 100 or 200 ng/ml) for 24 h. The expression of α‑smooth muscle actin (α‑SMA), collagen types I and III and connective tissue growth factor (CTGF) were then measured by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. The results demonstrated that 100 and 200 ng/ml concentrations of visfatin induced the expression of α‑SMA in culture‑activated rat HSC, which was accompanied by a significant increase in collagen types I and III, as confirmed by western blot and RT‑qPCR analyses. In addition, treatment of the HSC with certain concentrations of visfatin upregulated the expression of CTGF. These findings suggested that visfatin activated HSC and induced the production of collagen types I and III.

Histologic and immunohistochemical characterization of thymic epithelial tumours in the dog

Thymic epithelial tumour (TET) histologic subclassification has not been well described in the veterinary literature as it has in humans. The objective of this study was to identify and describe TET subtypes in dogs and to determine the utility of immunohistochemistry (IHC) in differentiating these subtypes. Samples were reviewed and classified according to a modified World Health Organization (WHO) criteria for human tumours of thymic origin. Signallment, presenting signs, treatment and survival data was collected from medical records. Histologic review confirmed the same subtypes as described in humans. Presence of high stage disease, pleomorphism, mitotic figures and capsular invasion was more common in atypical thymomas and thymic carcinomas than in thymomas. IHC was performed for GLUT-1, CD5, CD117 and CK8/18; however, this was not useful in classifying the tumours.

Mammary gland carcinoma in a dog with peripheral blood and bone marrow involvement associated with disseminated intravascular coagulation

A 7-year-old female Leonberger dog was referred to the National Veterinary School of Lyon Teaching Hospital with a 2-day history of anorexia and bleeding. A mammary mass had been removed 7 months earlier, but histologic examination was not performed. On physical examination, the dog was depressed and had pale mucous membranes and numerous petechiae and hematomas. Significant laboratory findings were moderate thrombocytopenia, prolonged prothrombin, activated partial thromboplastin, and thrombin times, hypofibrinogenemia, and increased concentration of fibrin(ogen) degradation products. A peripheral blood smear, buffy coat preparation, and bone marrow aspirate contained low numbers of large atypical cells that had moderate nuclear:cytoplasmic ratios, oval nuclei with multiple prominent nuclei, and basophilic cytoplasm with villous projections. A small nodule was found in the left inguinal mammary gland, and a fine-needle aspirate contained cells similar to those in blood and bone marrow. In samples of blood, bone marrow, and the mammary mass, the neoplastic cells were immunoreactive for cytokeratin. The diagnosis was mammary carcinoma with secondary disseminated intravascular coagulation (DIC) and disseminated tumor cells in bone marrow and circulating tumor cells in blood; this diagnosis was not confirmed by histopathologic examination. Owing to clinical deterioration and the poor prognosis, the dog was euthanized and a necropsy was not performed. This is the first report of a canine mammary carcinoma with circulating tumor cells and secondary DIC.