Haema 2010; 1(1): 21-28
G.A. Pangalis, S. Sahanas and M.Κ. Angelopoulou
Hematology Clinic of Iatriko Center Αthens-Psihiko, Hematology Clinic, University Medical School of Athens, “Laiko” General Hospital
Abstract
Angioimmunoblastic T-cell lymphoma (AITL) is a peripheral T-cell lymphoma predominantly seen in elderly patients. AITL usually presents with advanced stage disease, systemic symptoms, generalized lymphadenopathy, hepatosplenomegaly, pruritus, cutaneous rash, effusions, polyclonal hypergammaglobulinemia, anaemia and eosinophilia. Histologically there is a loss of lymphoid architecture with a polymorphous infiltrate, including small to medium size lymphocytes, plasma cells, eosinophils and immunoblasts. Proliferation of epithelioid post-capillary venules, increased numbers of dendritic cells and presence of large B-cell blasts often infected by the EBV are also distinctive pathological features of AITL. Several recent studies indicate that AITL is a neoplasm derived from a subset of CD4+ T cells normally found in reactive germinal centers (follicular helper T cells). Documentation of Bcl-6 and CD10 expression in the majority of AITL cases support the possible relationship of this lymphoma to the germinal center. Moreover, markers of normal follicular helper T cells (TFH) such as CXCR5, CD154, programmed death-1(PD-1) and slam associated protein (SAP), were demonstrated by immunohistochemistry in AITL. Non neoplastic cells that represent a major component of AITL have an important contribution to pathogenesis of this lymphoma and clinically the manifestations of the disease mostly reflect the results of reactions between neoplastic and non neoplastic cells. The pathogenic role of EBV is uncertain. Clinical course is variable, with occasional spontaneous remissions. Prognosis is dismal, with a median survival <3 years in most studies. The most commonly used treatment is CHOP or its variations. More aggressive regimens including stem cell transplantation and/ or combination of chemotherapy with anti T-cell monoclonal antibody or other novel agents such as anti-VEGF factor, bortezomib, pralatrexate and histone deacetylase inhibitors are currently under investigation.