Volume 12 Supplement 1
CD8 malignant proliferation in association with human T cell lymphotropic Virus 1 infection: a case report
© Kagdi et al. 2015
Published: 28 August 2015
Adult T cell leukaemia/lymphoma (ATL) is a predominantly CD4+ T cell neoplasia caused by human T cell lymphotropic Virus 1 (HTLV-1) infection. A few cases of CD8+ ATL have been reported but its existence has been debated. An Afrocaribbean female presented to the dermatology clinic with widespread papulo-nodular rash. HTLV-1 infection was detected by serology. Skin biopsy showed dense dermal infiltration by mainly CD8+ T cells which also expressed CD2, CD3, CD5, CD7 and occasionally CD25. Further investigations showed a mild lymphocytosis (4.4 x 106/L), circulating flower cells, absolute CD4+ count 1247 x 106/L (28.3% of lymphocytes), absolute CD8+ count x 2617 x 106/L (59.8% of lymphocytes), LDH 241 U/L (NR 135 – 214), Calcium 2.7 mmol/L (NR 2.2 – 2.6) but with increased serum PTH level. HTLV-1 proviral load (PVL) in peripheral blood mononuclear cells was 46%. PET/CT scan demonstrated FDG avid lymph nodes above and below the diaphragm. Axillary lymph node core biopsy showed CD20+ B cells nodules admixed with mainly small-to-medium sized T cells and a small population of large T cells. The small lymphocytes were mainly CD8+ T cells (also expressed CD2, CD3, CD5, and CD7 whereas the large cells expressed CD8, CD25 and CD30. Fewer than 5% expressed Ki67 (MIB-1). TCR clonality studies by PCR revealed expansion of an identical clone in all three compartments (skin, lymph node and blood). Detailed immunophenotyping on peripheral blood demonstrated a single dominant TCR vβ1+ clone (>90% of total CD8 T cells) which was CD3+, CD7+, CCR4+, CD25 low and, TSCL-1-. In summary we report a malignant CD8+ clone with atypical immunophenotype in a patient with high PVL. To confirm a working diagnosis of CD8+ ATL high throughput sequencing of each proviral integration sites is underway.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.