Angioimmunoblastic T-Cell Lymphoma: A Clinicopathologic Study of 158 Patients Treated in GELA (Groupe d’ Etude des Lymphomes de l’ Adulte) Trials.

Background: Angioimmunoblastic T-cell lymphoma (AITL), the second most frequent peripheral T-cell lymphoma, is characterized by a distinct clinical presentation and a spectrum of biological and morphologic features with little available data on prognostic factors in the literature.

Objective: to evaluate the prognostic significance of clinical, biological and pathological features in AITL.

Methods: between 1987 and 1998, 158 AITL patients were retrieved from the GELA LNH87 and LNH93 trials. Most patients received an anthracycline based polychemotherapy. Histologically, cases were reviewed by a panel of expert hematopathologists. For each case, at least 2 hematoxylin eosin slides were available for review together with an appropriate immunohistochemical staining including CD3, CD20 and CD21/CNA42. Cases were classified as “transformed” (>10% large B and/or T cells) and “classic” (including cases rich in clear cells, rich in epithelioid cells and with hyperplastic germinal centers). 62 cases were evaluated for CD10 and CXCL13 expression and scored according to the number of positive lymphoid cells.

Results: there was a slight male predominance (M/F=1.53). Median age was 62 years. 81%, 50%, 67% and 39% of patients had respectively an advanced stage, a non ambulatory PS, an IPI>2 and a PIT>2 (age>60y, PS>=2, LDH>=normal and bone marrow involvement). Anemia, positive coombs test and bone marrow involvement were observed in 65%, 33% and 47% of cases respectively. Hypergammaglobulinemia, elevated LDH levels and skin rash were observed in 15%, 66% and 44% of patients respectively. 41 cases were classified as transformed and 117 as classic including 20 epithelioid-cell rich, 14 clear-cell rich and 4 with hyperplastic germinal centers. CD10 and CXCL13 were clearly positive, in a fraction of the lymphoid infiltrate, in 71% and 73% of cases respectively. CR/CRu remission was observed in 46% of patients after induction therapy. With a median follow-up of 69 months, the 5y overall survival rate was 33%, reaching a plateau level around 6 years. Concerning PIT, patients with 0–1 factors and 3–4 factors had a 5y OS of 37% and 38% respectively. In univariate analysis, absence of CR/CRu (p<0.0001), hepatomegaly (p=0.0004), male gender (p=0.004), and anemia (p=0.05) were poor prognostic indicators for overall survival. Classic and transformed AITL were not different regarding clinical presentation, biological findings, and outcome except for a higher frequency of elevated serum LDH (p=0.0266) and b2 microglobulin levels (p=0.0456) within the transformed group. IPI and PIT were not predictive of survival.

Conclusion: despite of various intensive regimens with an anthracycline based chemotherapy, AITL pursues an aggressive clinical course and carries a poor prognosis. Our large series emphasizes the morphologic heterogeneity of AITL, without any clinical impact, and further confirms the common expression of CD10 and CXCL13.