Classification of distinct subtypes of peripheral T-cell lymphoma unspecified, identified by chemokine and chemokine receptor expression: Analysis of prognosis.

WHO classification for malignant lymphoma was recently proposed. However, PTCL is heterogeneous. Chemokines and its receptors are closely associated with the T-cell subtypes. To clarify the T-cell subtype in PTCL, we conducted DNA chips of chemokine, its receptor (R) and cytokines. Angioimmunoblastic T-cell lymphoma (AILD, n=4), anaplastic large cell lymphoma (ALCL, n=4), adult T-cell leukemia lymphoma (ATLL, n=7), NK-cell lymphoma (NKL, n=2) and PTCL, unspecified (PTCL-U, n=6) were analyzed using DNA chips. In addition, immunological stainings were performed in 280 cases. In DNA chip, AILD, ALCL, NKL and ATLL showed a tendency for respective clusters, otherwise, PTCL-U clustered with AILD, ALCL and ATLL. From the gene expression profiling, CCR4, CCR3, MIG, CXCR3 and BLC were selected for immunohistochemistry. ATLL (n=48) expressed CCR4. ALCL (n=26) expressed CCR3, NKL (n=20) expressed MIG, and AILD (n=29) expressed CXCR3 and/or BLC. From the expression patterns, PTCL-U (n=134) were classified into three groups; CCR4 type (CCR4(+), n=42), CCR3 type (CCR3(+), n=31) and CXCR3 type (CXCR3(+) BLC(+/-), n=54). The prognosis was poor for ATLL, intermediate for AILD and favorable for ALCL (P=0.0014). Among PTCL-U, CCR4 type, CXCR3 type and CCR3 type had prognoses equivalent to ATLL, AILD and ALCL, respectively (P<0.0001).