Accurate (V9, J144, Vim-13.2), Amersham, Biodesign (V9), Biogenesis (Vim-01, LN6), Biogenex (LN6, V9), Biotest (VIM 3B4), Boehringer Mannheim (3B4, V9), Chemicon, Cymbus Bioscience (VIM3B4), Dako (VIM3B4, V9), Diagnostic Biosystems (V9), Enzo, Immunotech (V9, V3260), Medac, Milab, Novocastra, Oncogene (V9), Pierce (ZSV5), RDI (VIM3B4), Serotec (J144), Sigma (LN9) and Zymed (ZSV5, ZC64).

Most antibody clones currently available are immunoreactive in fixed paraffin-embedded tissues and immunostaining is enhanced by HIER.

Vimentin is a 58 kD protein which has been purified from a variety of sources and has been shown to form homophilic filaments with an average diameter of 10 nm. Its name is derived from the Latin word vimentum, which means arrays of flexible rods. Similar to the other intermediate filaments, vimentin is a protein monomer of highly elongated fibrous molecules with an amino-terminal head, a carboxyl-terminal tail and a central rod domain. The latter consists of an extendeda-helical region containing long tandem repeats of a distinctive amino acid sequence motif called the hepatad repeat. This central rod domain shows a striking sequence homology between intermediate filaments of different species and an even more marked homology of as high as 30% between cytokeratin, desmin, glial fibrillary acidic protein, neurofilaments and vimentin of the same species. Immunohistochemical staining revealed vimentin filaments as part of a wavy network of filaments in the cytoplasm of fibroblasts, associated with both nuclear and plasma membranes. It has been suggested that vimentin, like other intermediate filaments, serves as a modulator between extracellular influences governing calcium flux into the cell and nuclear function at a transcriptional or translational level and may thus have a role in gene expression. Vimentin filaments can be precipitated as juxtanuclear whorls following treatment of cells with colcemid or vinblastine.

Vimentin is the most widely distributed intermediate filament and is expressed in virtually all mesenchymal cells and also by most other cell types in culture (Lane et al, 1983). With the widespread application of intermediate filament analysis to human neoplasms, it soon became apparent that although individual cell types and their corresponding tumors generally express a single intermediate filament class, several neoplasms may express more than one intermediate filament class (Azumi & Battifora, 1987). In many instances, this coexpression of one or more intermediate filament classes occurs in a predictable manner and may be employed as a diagnostic discriminator. Vimentin expression, traditionally accepted to be class specific for cells of the mesenchyme, can be coexpressed with cytokeratin in a number of epithelial cell types and their corresponding tumors. These include the endometrium, thyroid, gonadal epithelial cells, renal tubules, adrenal cortex, lung, salivary gland, hepatocytes and bile duct. Furthermore, there is increasing evidence to suggest that a variety of high-grade epithelial tumors may acquire the expression of vimentin intermediate filaments (Leong, 1991). Vimentin expression has been described in carcinomas of the skin (Iyer &
Leong, 1992), urinary bladder, breast (Raymond & Leong, 1989), prostate (Leong et al, 1988), gastric mucosa (Takemura et al, 1994) and uterine cervix. Several reports have indicated a correlation of vimentin expression with high tumor grades in breast carcinoma (Raymond & Leong, 1989; Heatley et al, 1993; Domogala et al, 1994; Koutselini et al, 1995) and ovarian epithelial malignancy (Nakopoulpou et al, 1995). One report suggested that vimentin expression was a poor prognostic marker in node-negative breast carcinoma (Domogala et al, 1990) although this has not been confirmed (Seshadri et al, 1996). Expression of vimentin in epithelial tumors also corresponds to changes in cell shape and forms from epithelioid to fibroblastoid or spindle forms so that vimentin is regularly expressed in spindle cell carcinomas.
Many tissues in embryos and fetuses, including surface ectoderm, neural groove and brain, gut mucosa and musculature, and renal tubular epithelium, display coexpression of vimentin with another intermediate filament during their developmental stages before being replaced by the intermediate filament protein specific for the mature tissue type (Goel et al, 1997). Vimentin is expressed in epithelial cells in vitro, culture preparations, cell suspensions and in exfoliated and metastatic cells in body fluids, suggesting that altered cell-to-cell contact and changes in cell shape may account for this apparent aberrant expression. Studies of cell cultures of mouse parietal endodermal cells led to the hypothesis that the acquisition of vimentin may be related to reduced cell-to-cell contact and the ability of epithelial cells to survive independently.
Immature muscle fibers contain desmin and vimentin and mature fibers lack vimentin. Regenerating muscle fibers react with anti-vimentin antibodies and more intensely for desmin than mature fibers. The detection of vimentin has therefore been applied to identify muscle regeneration, especially in cases of infantile spinal muscular atrophy and the high incidence of reactive fibers in some congenital and early-onset disorders may indicate developmental arrest (Bornemann & Schmalbruch, 1993).

Due to variability of fixation and HIER, vimentin has been used as an internal control or reporter molecule to assess the quality of antigen preservation and the uniformity of tissue fixation in fixed paraffin-embedded tissue sections (Battifora, 1991).

•Azumi N, Battifora H 1987. The distribution of vimentin and keratin in epithelial and non-epithelial neoplasms. American Journal of Clinical Pathology 88: 286-297.

•Battifora H 1991. Assessment of antigen damage in immunohistochemistry. The vimentin internal control. American Journal of Clinical Pathology 96: 669-671.

•Bornemann A, Schmalbruch H 1993. Anti-vimentin staining in muscle pathology. Neuropathology and Applied Neurobiology 19: 414-419.

•Domogala W, Lasota J, Dukowitz A 1990. Vimentin expression appears to be associated with poor prognosis in node-negative ductal NOS breast carcinomas. American Journal of Pathology 137: 1299-1305.

•Domagala W, Striker G, Szadowska A, et al 1994. P53 protein and vimentin in invasive ductal NOS breast carcinoma relationship with survival and sites of metastases. European Journal of Cancer 30A: 1527-1534.

•Goel A, Gupta I, Joshi K 1997. Immunohistochemical analysis of human embryos and fetuses. An insight into the mechanism of subversion of antigenic differentiation in neoplasia. Archives of Pathology and Laboratory Medicine 121: 719-723.

•Heatley M, Whiteside C, Maxwell P, Toner P 1993. Vimentin expression in benign and malignant breast epithelium. Journal of Clinical Pathology 46: 441-445. epithelium. Journal of Clinical Pathology 46: 441-445.

•Iyer PV, Leong AS-Y 1992. Vimentin expression in poorly differentiated squamous cell carcinomas of the skin. Journal of Cutaneous Pathology 19: 34-39.

•Koutselini H, Markopoulos C, Lambropoulou S, et al 1995. Relationship of epidermal growth factor receptor (EGFR), proliferating cell nuclear antigen (PCNA) and vimentin expression and various prognostic factors in breast cancer patients. Cytopathology 6: 14-21.

•Lane EB, Hogan BLM, Kurkinen M, Garrels JI 1983. Coexpression of vimentin and cytokeratins in parietal endodermal cells of early mouse embryo. Nature 303: 701-704.

•Leong AS-Y 1991. The expression of vimentin in epithelial neoplasms. Progress in Surgical Pathology 12: 31-48.

•Leong AS-Y, Gilham P, Milios J 1988. Cytokeratin and vimentin intermediate filament proteins in benign and malignant prostatic epithelium. Histopathology 13: 435-442.

•Nakopoulpou L, Stefanaki K, Janinis J, Mastrominas M 1995. Immunohistochemical expression of placental alkaline phosphatase and vimentin in epithelial ovarian neoplasms. Acta Oncologica 34: 511-515.

•Raymond WA, Leong AS-Y 1989. Vimentin a new prognostic parameter in breast carcinoma. Journal of Pathology 158: 107-114.

•Seshadri R, Raymond WA, Leong AS-Y, et al 1996. Vimentin expression is not associated with poor prognosis in breast cancer. Journal of Clinical Oncology 67: 353-356.

•Takemura K, Hirayama R, Hirokawa K, et al 1994. Expression of vimentin in gastric carcinoma: a possible indicator for prognosis. Pathobiology 62: 149-154.

Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.