LRPAP1 autoantibodies in mantle cell lymphoma are associated with superior outcome.

Low-density lipoprotein (LDL) receptor-related protein-associated protein 1 (LRPAP1) had been identified by B-cell receptor (BCR) expression cloning and subsequent protein array screening as a frequent and proliferation-inducing autoantigen of mantle cell lymphoma (MCL). Of interest, high-titered and light chain-restricted LRPAP1 autoantibodies were detected in 8 of 28 patients with MCL. In the present study, LRPAP1 autoantibodies in sera of patients treated within the Younger and Elderly trials of the European MCL Network were analyzed regarding frequency, association with disease characteristics, and prognostic impact. LRPAP1 autoantibodies were detected in 41 (13%) of 312 evaluable patients with MCL. These LRPAP1 autoantibodies belonged predominantly to the immunoglobulin G (IgG) class and were clonally light chain restricted (27 with κ light chains, 14 patients with λ light chains). Titers ranged between 1:400 and 1:3200. The presence of LRPAP1 autoantibodies was not significantly associated with any baseline clinical characteristic, however, it was associated with a superior 5-year probability for failure-free survival (FFS) of 70% (95% confidence interval [CI], 57% to 87%) vs 51% (95% CI, 44% to 58%), P = .0052; and for overall survival (OS) of 93% (95% CI, 85% to 100%) vs 68% (95% CI, 62% to 74%), P = .0142. LRPAP1-seropositive patients had a Mantle Cell Lymphoma International Prognostic Index-adjusted hazard ratio for FFS of 0.48 (95% CI 0.27-0.83, P = .0083) and for OS of 0.47 (95% CI 0.24-0.94, P = .032). LRPAP1 autoantibodies were frequently detected in a large cohort of MCL patients treated within prospective multicenter clinical trials. Our results suggest better outcomes for LRPAP1-autoantibody seropositive patients.

Unmutated immunoglobulin variable heavy-chain gene status remains an adverse prognostic factor after autologous stem cell transplantation for chronic lymphocytic leukemia.

An unmutated germ line configuration of the immunoglobulin variable heavy-chain gene (VH) has emerged to be a crucial adverse prognostic factor in chronic lymphocytic leukemia (CLL) under conventional treatment. The purpose of the present study was to investigate whether the VH mutational status retains its prognostic value in CLL also in the setting of autologous stem cell transplantation (SCT). Therefore, we investigated the mutational status in 58 patients with CLL who underwent myeloablative radiochemotherapy with SCT. Rearranged VH genes were analyzed by multiplex polymerase chain reaction (PCR) and direct sequencing using FR1 family-specific primers and JH consensus primers. Twenty patients (34%) showed less than 98% homology compared with germ line VH sequences and were considered as mutated, whereas 38 patients (66%) had an unmutated VH status (median mutational rate of 0%; range, 0%-1.7%). An unmutated VH configuration was strongly correlated with the presence of short lymphocyte doubling time (P =.003) and high lymphocyte count (P =.005). Time to clinical relapse and time to recurrence of monoclonal B cells as assessed by consensus IgH CDR3 PCR was significantly shorter in the group with unmutated VH genes (2-year probability 19% versus 0%, P =.0008, and 34% versus 9%, P =.0006, respectively). These results show that in CLL, an unmutated VH gene status of the tumor clone remains an adverse prognostic factor after SCT. Nevertheless, the hitherto only 3 deaths and the median treatment-free interval of 49 months in the unmutated cohort suggest a beneficial effect of SCT for this high-risk population in comparison to conventional treatment.