Immunoperoxidase examination of cutaneous infiltrates of mycosis fungoides and large-plaque atrophic parapsoriasis with OKT10

Cutaneous T-cell lymphoma: utility of antibodies to the variable regions of the human T-cell antigen receptor

BACKGROUND

The clonotypic 90 kd Ti heterodimer of the human T-cell antigen receptor is composed of two distinct chains (alpha beta or rarely tau delta) that result from the recombination of variable (V), constant, joining, and, in the case of beta chains, additional diversity regions.

OBJECTIVE

The variable region expression of human cutaneous T-cell lymphoma (CTCL) was studied.

METHODS

Biopsy specimens from 13 patients with CTCL (7 plaque, 3 tumor stage, 3 Sézary syndrome) were examined immunohistochemically by a panel of seven commercially available monoclonal V-region antibodies.

RESULTS

Two patients had significant anti-V-region staining. One patient with Sézary syndrome had two lesions, subjected to biopsy 4 months apart, that reacted with beta V5(a), a specificity previously documented by flow cytometry of leukemic cells. A patient with plaque-stage CTCL, negative for T-cell gene rearrangement by Southern blot, demonstrated reactivity with beta V5(c) largely limited to epidermotropic lymphocytes.

CONCLUSION

Panels of V-region antibodies should be useful reagents for diagnosis and follow-up of CTCL.

Clinical implications of immunologic phenotyping in cutaneous T cell lymphoma

The composition of cutaneous lesions from 158 patients with confirmed cutaneous T cell lymphoma, 91 patients with suspected cutaneous T cell lymphoma, and 145 patients with lymphoid disorders other than cutaneous T cell lymphoma was quantitated in situ with the use of commercially available murine monoclonal antibodies that identify the Pan T, T-helper/inducer (Th), T cytotoxic/suppressor (Ts), and Pan B lymphocyte subsets. On average, cutaneous infiltrates of confirmed cutaneous T cell lymphoma were found to contain significantly more Th and less Ts or Pan B cells compared to benign lymphoid disorders. Moreover, when analyzed in terms of the type of lesion examined by biopsy, the absolute amount of Th cells progressively expands with increasing magnitudes of infiltrate in the dermis while the amount of Ts and Pan B cells remains relatively constant among lesions. A useful diagnostic criterion (anti-Leu 1/4 greater than or equal to 70% and anti-Leu 3a/anti-Leu 2a ratio greater than or equal to 6) correctly discriminated between cutaneous T cell lymphoma and non-cutaneous T cell lymphoma in 87.5% of cases. A positive immunodiagnostic result also may be useful for the prediction of subsequent histopathologic confirmation of cutaneous T cell lymphoma in patients who have suspect lymphoid infiltrates, such as alopecia mucinosis or idiopathic generalized erythroderma, when first seen. With the use of multivariate analysis, stage and possibly the percentage of Th cells within the T cell component in cutaneous infiltrates were covariates with significant relationships to survival in patients with confirmed cutaneous T cell lymphoma. In addition, Ts cells in infiltrates did not correlate significantly with observed responses to topical treatment and subsequent course in pretumorous mycosis fungoides. These results indicate that Ts cells play little biologic role in modifying the natural history of cutaneous T cell lymphoma.

Immunophenotype of lymphoid cells in positive patch tests of allergic contact dermatitis

The immune phenotype of the infiltrating cells in 13 positive patch tests from 8 cases of contact dermatitis and 1 case of poison ivy was studied. An indirect immunoperoxidase technique was used in conjunction with monoclonal antibodies directed against mature T cells (Leu-1, T11), helper T cells (Leu-3A), suppressor/cytotoxic T cells (Leu-2A), killer and natural killer cells (HNK 1), B cells (B1), Langerhans cells (HLA-DR), and the common acute lymphoblastic leukemia antigen (CALLA), (J5). The majority of infiltrating mononuclear cells were Leu-1+, T11+, Leu-3A+, Leu-2A-, HLA-DR+, T9-, T10-, HNK-, B1-, J5-. Occasional T6+ cells were observed in the epidermis (including spongiotic microvesicles) and also isolated in the dermis and within the dermal mononuclear infiltrates. The phenotype was compared with cutaneous T-cell lymphoma, a disease in which contact allergy and antigenic persistence may play a role.

Monoclonal antibodies and cutaneous T cell lymphoma. Theoretical and practical considerations

The T cell nature of mycosis fungoides and Sézary syndrome was established a decade ago. The recent advent of monoclonal antibodies to T cells and other lymphoid subpopulations has resulted in an explosion of knowledge on the biology of this group of disorders. These reagents have increased our knowledge on thymic differentiation status, pathogenesis, the phenotype of premalignant vs malignant lymphocytic infiltrates, the identification of other previously unrecognized cells within lymphomas, and the phenotype of circulating vs skin lymphocytes. Therapeutic applications may result. These new developments are discussed.