Expression of the CD1a molecule in B- and T-lymphoproliferative skin conditions

Abstract

The skin immune system is characterized by the presence of two types of CD1a expressing cells: Langerhans cells and dermal dendritic cells, which are professional antigen processing and presenting cells. It is well established that several dermatoses are associated with T-cell mediated immune responses. In these pathological skin conditions, T-cells are activated by professional antigen presenting cells and dendritic cells are the most potent antigen presenting cells for both Thelper cells and T-cytotoxic cells. Therefore, it is plausible that dendritic cells are crucially involved in the pathogenesis of lymphoproliferative skin conditions characterized by the presence of a T-cell infiltrate. In this study, we examined the frequency and distribution of CD1a expressing cells and CD3 + cells in both the dermal and epidermal compartment in a wide range of lymphoproliferative dermatoses with a T-lymphoid infiltrate. In the skin conditions investigated, the CD1a molecule was highly expressed in mycosis fungoides, T-cutaneous lymphoid hyperplasia, lymphomatoid papulosis and parapsoriasis, whereas few CD1a-positive cells were observed in cutaneous B-cell lymphomas. Our study demonstrates a distinct pattern of CD1a staining in the infiltrates of cutaneous lymphoproliferative disorders which may reflect different immunoregulatory events involving T-lymphocytes and CD1a-positive dermal and epidermal dendritic cells.

Origin Use of CD4, CD8, and CD1a Immunostains in Distinguishing Mycosis Fungoides from its Inflammatory Mimics: A Pilot Study

“…This increase is also seen in other T-cell proliferations, like lymphomatoid papulosis, but not in B-cell lymphomas. [15] Goteri et al . showed that an increased dermal (but not epidermal) CD1a+ cells correlated with the density of the neoplastic infiltrate.…”

Head and neck lesions of Kimura's disease: Exclusion of human herpesvirus-8 and Epstein-Barr virus by in situ hybridisation and polymerase chain reaction. An immunohistochemical study

“…This fact also helps to rule out that H&N-KD (or any antigenic stimulation in the lesions) originates from Langerhans cells. It is possible that the B-cell proliferation hampers the recruitment of CD1a+ cells in T-cell-rich areas via certain inhibitory cytokines (Pigozzi et al, 2006).…”

Actualización en diagnóstico y manejo de micosis fungoide y síndrome de Sézary

“…Dentro de las teorías propuestas se encuentran una predisposición genética (por la relación con determinados alelos de HLA clase II en población judía), 5 una estimulación antigénica crónica que llevaría a una proliferación clonal descontrolada de linfocitos T (dado el aumento en el número de células dendríticas y la mayor expresión de B7/CD28 y CD40/CD40L en lesiones tempranas, [7][8][9] así como la mayor expresión de receptores tipo Toll 2, 4 y 9 en queratinocitos), 10 infecciones (particularmente por estafilococo aureus, ya que se ha demostrado su colonización en MF eritrodérmica y en síndrome de Sézary; 11 a diferencia de algunos linfomas cutáneos agresivos, no se ha logrado demostrar una asociación entre MF y virus de Epstein Barr o HTLV-1 12,13 e inmunosupresión (por la asociación infrecuente con trasplantados de órganos sólidos 14 y pacientes portadores de VIH).…”