Frequency and clonality of peripheral gamma delta T cells in psoriasis patients receiving anti-tumour necrosis factor- alpha therapy

• Published in: Clinical and experimental immunology Vol. 177; no. 1; pp. 142 - 148
• Main Authors: Kelsen, J, Dige, A, Christensen, M, D'Amore, F, Iversen, L
• Format: Journal Article
• Language: English
• Published: 01.07.2014
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/cei.12331

Hepatosplenic gamma delta T cell lymphoma (HSTCL) has been observed in patients with Crohn's disease (CD) who received anti-tumour necrosis factor (TNF)- alpha agents and thiopurines, but only one case was reported in a psoriasis patient worldwide. This difference could be due to differences in either the nature of the inflammatory diseases or in the use of immunomodulators. We investigated the impact of anti-TNF- alpha agents on the level and repertoire of gamma delta T cells in peripheral blood from psoriasis patients. Forty-five men and 10 women who were treated with anti-TNF- alpha agents for psoriasis were monitored for a median 11 months for the level and clonality of gamma delta T cells via flow cytometry and polymerase chain reaction (PCR) analysis of T cell receptor gamma (TCR- gamma ) gene rearrangements. Seventeen men had a repeated analysis within 48 h of the infliximab infusion to reveal a possible expansion of gamma delta T cells, as observed previously in CD patients. Ten psoriasis patients who were never exposed to biologicals and 20 healthy individuals served as controls. In the majority of psoriasis patients, the level and clonal pattern of gamma delta T cells was remarkably stable during infliximab treatment. A single male patient repeatedly experienced a significant increase in the level of gamma delta T cells after infliximab infusions. A monoclonal gamma delta T cell repertoire in a polyclonal background tended to be more frequent in anti-TNF- alpha -treated patients than naive patients, suggesting that anti-TNF- alpha therapy may promote the clonal selection of gamma delta T cells in psoriasis patients.