Serum IgA level, monocyte count, and international prognostic index are independently associated with overall survival in patients with HTLV-I-negative nodal peripheral T cell lymphoma.

Peripheral T cell lymphomas (PTCL) account for 10-15 % of non-Hodgkin's lymphomas and are associated with poor prognosis. Although many prognostic factors for PTCL have been proposed, the heterogeneity of PTCL seems to be an obstacle in the establishment of clinically useful prognostic system, such as the International Prognostic Index (IPI) in diffuse large B cell lymphoma. PTCL with nodal manifestation include the HTLV-I-negative histologic subtypes of PTCL not otherwise specified (PTCL-NOS), angioimmunoblastic T cell lymphoma (AITL), and anaplastic large cell lymphoma (ALCL). As PTCL-NOS encompasses a group of similar tumors and mostly shares their clinical pictures, we retrospectively analyzed clinical data from 77 patients diagnosed with ALCL, AITL, and PTCL-NOS at Kobe City Medical Center General Hospital from May 1994 to February 2012 to identify the prognostic factor for nodal PTCL. The median age of patients was 64 years, ranging from 23 to 83 years. With a median follow-up of 50 months, 5-year overall survival (OS) was 43 %. Multivariate analysis identified high-risk IPI (hazard ratio (HR), 4.04; P = 0.015), absolute monocyte count > 0.8 × 10(9)/L (HR, 3.44; P = 0.001), and serum concentration of IgA > 410 mg/dL (HR, 2.31; P = 0.013) as poor prognostic factors for OS. Thus, we have identified novel prognostic factors of monocyte count and serum IgA level for nodal PTCL. Although conventional prognostic models mainly reflect both tumor characteristics and host factors, the present model indicates the importance of host immune response as the unfavorable prognosis.