Immunohistochemical Expression of TCRβ Predicts Achievment of Complete Remission in Enteropathy-Associated T-Cell Lymphoma

Enteropathy associated T-cell Lymphoma(EATL) is a distinctive clinicopathological entity but knowledge about potential prognostic factors in this disease is very limited.

Clinicopathological and immunohistochemical analysis of single center EATL cohort focusing especially on stromal components, activation molecules and potential loss of TCR receptors.

Detailed clinical analysis of a cohort of 21 patients from the southern-west Germany was performed. Additionally broad panel of immunohistochemical staining including MUM1IRF4, Blimp-1, FoxP3, TCR γ, TCRβ, CD11c was done. Univariate statistical analysis of survival was performed.

The study group comprised of 12 males and 9 females, aged 37–86, with the median survival time of 5 months after the initial diagnosis. Following clinical factors turned out to be connected with longer overall survival (OS): age ≤ 60years (p=0, 007), Ann Arbor Stadium I+II (p =0, 048), good general condition (p = 0, 0068), IPI 1–3 (p=0, 004), usage of anthracycline in the chemotherapy regimen (p=0, 0504).

Longer event free survival(EFS) was connected with good general condition (p=0, 023) usage of anthracycline (p=0, 047).

There was 17 Type I cases (81%) and 4 Type II (19%). EATL type, histological variants of neoplastic cells, perivascular and angiocentric growth pattern as well as tissue eosinophilia did not influence survival. There was a strikingly strong infiltration of the neoplastic infiltrate by CD11c+ dendritic cells in 9/21 cases, but it was prognostically irrelevant. MUM1/IRF4 expression was observed in 8/19(42, 1%), Blimp-1 in 5/14 (35, 7%) and FoxP3 in 7/20 (35%), but only FoxP3 positivity was connected with longer EFS. There was a trend toward worse OS (p=0, 18) and EFS (p=0, 12) in Blimp-1 positive cases.

Expression of TCRβ was observed in 4/21(19%), of TCRγ in 3/21(14, 3%) while the majority of cases (14/21), showed loss of expression of both proteins. There was a trend toward longer OS (p=0, 19) and EFS (p=0, 16) in TCR β+ than in TCRγ+ and TCR γ-β- cases.

TCRβ expression was statistically significant more frequent in patients that achieved complete remission (3/7) than in group that did not achieve CR (1/14, p=0, 049).

In EATL several clinical factors can provide relevant prognostic information. Immunohistochemical expression of FoxP3, Blimp-1 and TCRβ seems also to be prognostically usefull. TCRβ is the only marker that can predict response to the chemotherapy in this very aggressive neoplasm.

Finke:Fresenius Biotech GmbH: Honoraria, Research Funding.