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CD44 variant expression in cutaneous T‐cell lymphoma
Author(s) -
Orteu C. H.,
Li W.,
Allen M. H.,
Smith N. P.,
Barker J. N. W. N.,
Whittaker S. J.
Publication year - 1997
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/j.1600-0560.1997.tb00802.x
Subject(s) - mycosis fungoides , cd44 , lymphoma , pathology , medicine , lymph node , immunohistochemistry , lymph , biology , cell , genetics
Expression of the lymphocyte homing receptor CD44 and its splice variants have been linked to tumour dissemination and poor prognosis in non‐Hodgkin's lymphoma. Specifically, the in vitro expression of variant exon V6 confers metastatic potential in rat pancreatic carcinoma cell lines. In this study, we investigated the expression of CD44 splice variants in cutaneous T‐cell lymphomas, including patients with mycosis fungoides (MF), Sezary syndrome (SS), large‐cell anaplastic lymphoma (LCAL) and HTLV1‐associated cutaneous lymphoma. In addition, 4 involved lymph nodes from 2 patients with MF and 1 patient with SS were examined. Inflammatory dermatoses, lichen planus and psoriasis, and normal skin were also studied. Immunohistochemistry was performed using a panel of monoclonal antibodies, including those with specificity for CD44H (standard isoform) and variant exons V3, V6 and V8‐9. Normal epidermal keratinocytes were consistently CD44H and CD44 V3, V6 and V8‐9 positive. In all the different clinicopathological subtypes and stages of cutaneous T‐cell lymphomas, including involved lymph nodes, tumour cells consistently expressed CD44H, but were CD44 V3 and V6 negative. CD44 V8‐9 was expressed on a majority of tumour cells in 2/5 LCAL and on occasional tumour cells in 2/5 LCAL. Occasional V8‐9 positive tumour cells were also identified in 6/13 MF, 1/4 SS and 3/4 HTLV1. In 2/3 lymph node samples from 2 patients with tumour‐stage MF, CD44 V8‐9 expression was found on a small percentage of atypical mono‐nuclear cells. Scattered V8‐9 positive dermal mononuclear cells were present in sections of lichen planus and psoriasis. We have found no evidence to suggest that the metastasis‐associated CD44 variant exon (V6) is expressed in cutaneous T‐cell lymphoma, or that CD44H expression is associated with an adverse prognostic group. It is not clear whether the strong expression of CD44 V8‐9 in 2 patients with CD30 positive LCAL reflects activation status or metastatic potential.