Enteropathy-Associated T-Cell Lymphoma Type I, But Not Refractory Celiac Disease, Strongly Expresses CD30 and Might Benefit From Brentuximab Vedotin

Enteropathy-associated T-cell lymphoma (EATL) is an intestinal tumor of intraepithelial T lymphocytes. The 2008 WHO classification distinguishes two types of EATL: the first type of EATL (type I), the most frequent (80-90%) is strongly associated with celiac disease (CD) and the HLA-DQ2/DQ8 haplotypes. The tumor cells are CD3+CD8-/+CD4-CD56- and contain cytotoxic granules. In almost all cases, a varying proportion of the tumor cells express CD30. The second type of EATL (type II), the monomorphic form, has a distinct immunophenotype (CD3+CD4-CD8+CD56+). In two types, TCRgamma genes are often clonally rearranged.

EATL may be preceded by refractory celiac disease (RCD), corresponding to CD refractory to gluten free diet (GFD). RCD is divided in two types based on the absence (type I) or presence (type II) of abnormal intraepithelial lymphocytes (IEL) showing down-regulation of CD8 and often TCRgamma genes rearrangement. RCD II is now considered as a small cell intraepithelial T-cell lymphoma that could be an intermediate stage between CD and EATL.

The aim of the present study was to establish the pattern of CD30 expression in EATL. This could have therapeutic implications with the use of anti-CD30 monoclonal antibody like brentuximab vedotin (BV).

Consecutive adult patients (pts) diagnosed with EATL between 2007 and 2013 in two university hospitals in Paris (Necker University Hospital and Georges Pompidou European Hospital) were eligible for this study. Diagnosis was confirmed after histopathologic and immunohistochemical review. For the purpose of the present study, two expert hematopathologists (V.V. and N.B.) reviewed all EATL and extended the phenotypic analysis to reclassify them according to the 2008 WHO classification. A panel of antibodies directed against CD20, CD3, CD4, CD5, CD8, CD56, granzyme B and ALK1 was used. CD30 staining was performed with Monoclonal Mouse Anti-Human CD30, Clone Ber-H2 (Dako). Consecutive RCDI and RCDII cases with complete phenotype and clonality analyses diagnosed in the same period were used as control. Diagnosis of CD was based on HLA-DQ2/8 typing, detection of celiac specific antibodies and of villous atrophy with increased counts of IEL on normal diet. Pts were further classified in RCDI or II depending on their clinical and histological response to a GFD and the presence of abnormal IEL.

Twenty five adults were diagnosed with EATL on consensus review (median age 53 years [range 34-76], M/F ratio 12/13). Twenty five RCDI pts (median age 51 years [range 16-75], M/F ratio 6/19) and 20 RCDII pts (median age 62 years [range 29-81], M/F ratio 7/13) were used as control. A clinical history of CD was found in 17/20 (85%) evaluable EATL pts. Histological features of CD/RCD were seen in all cases (20/20) of EATL in which the mucosa adjacent to the tumor could be investigated (half of these were RCDII). Primary sites of EATL were small intestine (20/25), mesenteric lymph nodes (3/25), peritoneal nodules (1/25) and spleen (1/25). Phenotypic analysis showed that EATL cases were all WHO type I (25/25). ALK1 was constantly negative.

IEL were CD3+ in all 70 cases. CD8 was normally expressed in all RCDI IEL and downregulated in all RCDII IEL and 35% of EATL.

In all cases of EATL (25/25), CD30 was strongly expressed by all large tumor cells. In RCDI and II, CD30 was negative in most cases (∼90%), and was rarely expressed by dispersed atypical lymphocytes (IEL or in lamina propria) in some cases.

TCRgamma genes were clonally rearranged in 11/14 (79%) EATL, 3/25 (12%) RCDI and 18/20 (90%) RCDII.

Based on these results, we initiated in 2012 a pilot study combining BV with chemotherapy followed by autologous stem-cell transplantation (ASCT) as frontline treatment of EATL. Five pts have currently been treated. The associated chemotherapy regimen was IVE/MTX (Sieniawski M, Blood 2010) for the first two pts. After presentation at ASH 2012 Annual Meeting of preliminary results of a phase 1 study combining BV with CHP regimen as frontline treatment of systemic ALCL and other CD30-positive mature T–cell and NK–cell lymphomas (Fanale MA, Abstract #60), we replaced IVE/MTX by CHP regimen, and treated 3 other pts. The treatment was well tolerated, and the 5 pts reached CR and underwent ASCT.

CD30 is strongly expressed in EATL type I. Promising results of the combination of BV with CHP led us to plan a phase 2 study of BV and CHP followed by ASCT as frontline treatment of EATL.

Off Label Use: Brentuximab vedotin was used in enteropathy-associated T-cell lymphoma (EATL).