Gunhild L. Vejlsgaard

T‐cell receptor γδ‐positive peripheral T‐cell lymphomas presenting in the skin:

Abstract Examination of biopsy samples from 62 patients with – or with suspected – cutaneous T‐cell lymphoma (CTCL) revealed 2 cases in which the neoplastic cells were positive for the T‐cell receptor (TCR) γδ complex. One patient had mycosis fungoides and 1 patient had a pleomor‐phic lymphoma of medium and large‐cell type. Both cases showed aggressive courses with dissemination to internal organs and short survival times. The phenotypic examination showed that the neoplastic cells were positive with TCRδ1, CD3, CD25, CD29, CD45RO and CD54. No staining was seen with antibodies against framework determinants or variable regions on the TCR αβ heterodimer. Negative reactions were also seen with CD4, CD8, CD5, CD7, CD16, CD30 and CD57. It is concluded that rare CTCL express TCR γδ chains. These malignancies may originate from the TCR γδ‐positive T cells seen in normal skin, and it is possible that their recognition may be important for clinical reasons.Examination of biopsy samples from 62 patients with--or with suspected--cutaneous T-cell lymphoma (CTCL) revealed 2 cases in which the neoplastic cells were positive for the T-cell receptor (TCR) gamma delta complex. One patient had mycosis fungoides and 1 patient had a pleomorphic lymphoma of medium and large-cell type. Both cases showed aggressive courses with dissemination to internal organs and short survival times. The phenotypic examination showed that the neoplastic cells were positive with TCR delta 1, CD3, CD25, CD29, CD45R0 and CD54. No staining was seen with antibodies against framework determinants or variable regions on the TCR alpha beta heterodimer. Negative reactions were also seen with CD4, CD8, CD5, CD7, CD16, CD30 and CD57. It is concluded that rare CTCL express TCR gamma delta chains. These malignancies may originate from the TCR gamma delta-positive T cells seen in normal skin, and it is possible that their recognition may be important for clinical reasons.

Immunophenotypic studies in cutaneous T‐cell lymphomas: clinical implications

Examination of biopsies from 62 patients with, or suspected of having cutaneous T‐cell lymphoma (CTCL) revealed 24 cases in which the neoplastic cells expressed aberrant or suppressor T‐cell phenotypes. The clinical records of these patients were reviewed in an attempt to establish whether recognition of these phenotypes has any clinical implications. Twelve patients had mycosis fungoides (MF) with plaques (n=4) or tumours (n=8), four had Sézary syndrome, and eight had large‐cell lymphomas of pleomorphic (n=6) or anaplastic subtype (n=2). Most of the large‐cell lymphomas behaved aggressively, as might have been expected from their cytological appearance. Aggressive courses were also seen in Sézary syndrome, and in tumour lesions of MF, whereas the behaviour in cases of plaque lesions was indolent. Again, this might have been anticipated from the clinical staging and routine histological examination. It is suggested that the expression of aberrant or suppressor T‐cell phenotypes in CTCL is not of independent prognostic significance, but that the stage and histology are more important. This issue is an important topic for a prospective analysis.

IgE-binding components of staphylococcal enterotoxins in patients with atopic dermatitis.

Background The exacerbation of atopic dermatitis may be associated with infection of the skin with Staphylococcus aureus ( S. aureus ). S. aureus isolated from the skin of patients with atopic dermatitis secretes enterotoxin A, B, and toxic shock syndrome toxin 1. This is of interest because these patients may develop specific IgE antibodies against components from staphylococci. Objective The objective was to demonstrate IgE-sensitization to components of Staphylococcus aureus enterotoxins A and B (purified and partially purified), toxic shock syndrome toxin 1, and the bacterial cell component lipoteichoic acid, in patients with atopic dermatitis. Methods Blood samples from 34 patients with atopic dermatitis and 10 controls were tested by leukocyte histamine release to the enterotoxins and lipoteichoic acid. The toxins were separated by sodium dodecylsulfate polyacrylamide gel electrophoresis and analyzed by IgE-immunoblotting with sera from the same patients. Results The majority of patients (96%) with clinical signs of skin infection produced specific IgE-antibodies to all three toxins. Nearly half of the patients produced IgE to enterotoxin A and B. Only 63% of the patients with atopic dermatitis showed cellular response judged by the release of histamine from patient basophils when challenged in vitro with the toxins. This may indicate clinically unimportant sensitization in a number of patients. The immunoblotting revealed that the major allergens of the toxins were 24 and 28 kD proteins. Partially purified toxins showed a higher frequency of leukocyte histamine release responses than purified toxin. The only obvious difference was a difference in the content of pure toxin of the two preparations. Lipoteichoic acid showed nonspecific activity. Conclusions These findings suggest that staphylococcal enterotoxins may act as specific allergens and induce IgE-antibodies to enterotoxins that may exacerbate the skin inflammation in some patients with atopic dermatitis.

THE CELLULAR IMMUNE RESPONSE TO HUMAN PAPILLOMAVIRUS INFECTION

This review will concentrate on the human cellular immune response associated with the HPV infection

Evaluation of the wound healing potential in human beings from the subcutaneous insertion of expanded polytetrafluoroethylene tubes

Subcutaneous insertion of expanded polytetrafluoroethylene tubes with local anesthesia constitutes a minimally invasive model permitting quantitative and qualitative studies of the wound healing potential in human beings. Light and electron microscopic examination of these implants in rats showed a normally appearing granulation tissue. The amount of hydroxyproline accumulated in the expanded polytetrafluoroethylene tubes may be assayed and converted to collagen content. In 28 surgical patients, the collagen content increased from 6.6 µg/cm (interquartile range: 5.1 to 9.9) after 5 days to 12.4 µg/cm (7.1 to 16.8) after 10 days (p < 0.05). The median ratio between the higher and lower collagen amount measured in two expanded polytetrafluoroethylene tubes inserted for an identical period within the same patient was 1.25 (1.10 to 1.81). This variability ratio was not related to the amount of collagen accumulated or the duration of implantation. There was a tendency for higher collagen amounts in the middle section than in the ends of the expanded polytetrafluoroethylene tubes, with a median ratio between the two sections equaling 1.12 (0.96 to 1.58); (p > 0.05). No infectious or hemorrhagic complications from the insertion occurred in any of the patients. Increments of collagen deposition with time may be easily assessed by this expanded polytetrafluoroethylene tube model, which is inexpensive and has high patient acceptance. Measurement variability was encountered, which has to be taken into account when designing clinical trials.

Use of antibodies against the variable regions of the T‐cell receptor α/β heterodimer for the study of cutaneous T‐cell lymphomas

Summary Recent studies have suggested that antibodies against the variable (V) regions of the T‐cell antigen receptor (TCR) may be used as markers for clonality and malignancy in T‐cell infiltrates. We have investigated this by examining biopsy samples from 45 patients with cutaneous T‐cell lymphomas (CTCL) for reactivity with seven antibodies against different V‐gene families on the TCR α/β heterodimer, i.e. ICI (VβSa), W112 (Vβ5b), OT145 (Vβ6a), 16G8 (Vβ8a), S511 (Vβ12a), Fl (Vα2a) and LC4 (αβVa). Serial biopsies were available in 13 patients and a total of 62 samples were studied. The neoplastic cells in five cases were positive for either Vβ5 (one case), Vβ6 (one case), Vβ8 (two cases) or Vβ12 (one case). In the remaining 40 cases, no staining was seen of the neoplastic cells. These findings indicate that while antibodies against the TCR V‐regions may be used as clonotypic markers for certain T‐cell neoplasms, there is as yet not a sufficient number of anti‐TCR V‐region antibodies available for the routine diagnosis of these conditions.

Expression of a cell adhesion protein (VLA β) in normal and diseased skin

Biopsies from normal skin (n= 17) and various cutaneous disorders (n= 83) were examined immunohistologically for reactivity with an antibody (CD29) against the common β chain of the VLA integrin family. In normal skin. CD29 recognized a number of cell types, i. e. endothelial cells, fibroblasts. T lymphocytes and basal keratinocytes. Similar cells were positive in diseased skin, but the expression of VLA β was upregulated on keratinocytes. The phenotype of the VLA β‐positive T cells was examined in more detail by staining with anti‐T‐cell antibodies. i. e. CD3, CD4, CD8, CD45RO (UCHLI) and CD45R (2H4). These studies showed that most of the T cells in normal skin, benign cutaneous conditions and early cutaneous T‐cell lymphomas (CTCL) expressed a similar phenotype and resembled antigen committed ‘memory’ (helper/inducer) cells (CD4+, CD29+, CD45RO+, CD45R−). In advanced CTCL, expression of these antigens was more variable, and many of these infiltrates showed aberrant (or unusual) expression of CD29, CD45RO, CD45R and other T‐cell antigens. It is concluded that several cells involved in cutaneous immune reactions express a molecule (VLA β) which acts as a receptor for extracellular matrix components. This molecule is important for the attachment of cell to connective tissue constituents and may act to facilitate the migration of lymphocytes (and other cells) during immune reactions in normal and diseased cutaneous conditions. Advanced CTCL differ from the early lesions and it is possible that there is a progressive accumulation of increasingly malignant (or transformed) cells in these conditions.

Activation of Reactive Versus Malignant T Cells in Cutaneous T Cell Lymphoma: Role of Abnormal Antigen Presenting Cells and T Cell Activating Molecules

We review our data suggesting that interactions between reactive and malignant T cells in lesions of cutaneous T cell lymphoma (CTCL) may play a role in the biology of CTCL. T cell receptor gene rearrangement (TCRGR) analysis allows the identification of the malignant clone on the basis of the unique size of the TCR gene fragments after enzyme digestion. We identified the malignant clone by TCRGR analysis of DNA extracts from lesionai skin of patients with CTCL, mycosis fungoides type, and compared the TCRGR pattern to that of T cell clones established from lesionai skin of the same patients. We found that each clone demonstrated a TCRGR pattern unique from the others and different from that of the malignant clone identified in the lesion. These data established that a polyclonal population of tumor infiltrating lymphocytes (TEL) are present in the lesion (and potentially regulating the malignant clone), and also suggest that the malignant clone and the TIL’s may have different activation requirements. Intralesional activation of malignant or TIL clones may be induced by abnormal antigen presenting cells (APC’s) in the lesion. We showed that lesionai CDla+ cells (Langerhans cells;LC), purified on immunomagnetic beads, demonstrated ultrastructural abnormalities such as hyperconvoluted nuclei and significant melanophagocytosis. In addition, these LC demonstrated strong expression of CD36, CD11c and CD1c, markers normally more highly expressed on dermal perivascular dendritic cells, in addition to expression of molecules present on normal LC, such as HLA-DR and CDla. Although these modulated LC are hyperstimulatory for autologous T cells, it is not yet clear whether they are stimulating the malignant clone or the TIL’s in the lesion. The balance between progression versus indolence may be related to complex interactions between the cells of the malignant clone, TIL’s, and APC’s.

In cutaneous T-cell lymphoma, class II MHC molecules on CD1+ antigen-presenting cells are upregulated in involved compared with uninvolved epidermis

CD1+ antigen‐presenting cells in involved epidermis of patients with cutaneous T‐cell lymphoma exhibit an enhanced functional capacity to activate autologous CD4+ T cells compared with CD1+ antigen‐presenting cells from uninvolved and normal epidermis. Class II major histocompatibility complex molecules are involved in antigen presentation, and their expression on CD1+ Langerhans cells is known to vary. The expression of all three class II (HLA‐DR, ‐DQ, ‐DP) molecules was therefore determined on CD1+ epidermal cells from both involved and uninvolved epidermis, using flow cytometry. The involved CD1+ epidermal cells exhibited a 1.5–1.6‐fold, statistically significant increase in fluorescence intensity after staining of the class II molecules (HLA‐DR, ‐DQ, ‐DP) compared with CD1+ epidermal cells from uninvolved epidermis. The autologous CD4+ T‐cell activation was almost completely blocked by anti‐HLA‐DR, and partly by anti‐HLA‐DQ and anti‐HLA‐DP.