Citations

Abstract Mantle-cell lymphoma (MCL) is a unique subtype of B-cell non-Hodgkin lymphoma (NHL) that behaves aggressively and remains incurable. In order to understand the pathogenesis of MCL and design new therapies, it is important to accurately analyze molecular changes in pathways dysregulated in MCL. We used antibody microarrays to compare patterns of protein expression between CD19+ purified B lymphocytes from normal tonsil and 7 cases of histologically confirmed MCL. Protein overexpression was defined as a higher than 1.3-fold or 2-fold increase in at least 67% of tumor samples compared with normal B-cell control. Of the polypeptides, 77 were overexpressed using the higher than 1.3-fold cutoff, and 13 were overexpressed using the 2-fold cutoff. These included cell cycle regulators (regulator of chromosome condensation 1 [RCC1], murine double minute 2 [MDM2]), a kinase (citron Rho-interacting kinase [CRIK]), chaperone proteins (heat shock 90-kDa protein [Hsp90], Hsp10), and phosphatase regulators (A-kinase anchor protein 1 [AKAP149], protein phosphatase 5 [PP5], and inhibitor 2). The elevated expression of some of these polypeptides was confirmed by immunoblotting and immunohistochemistry, whereas elevated expression of others could not be confirmed, illustrating the importance of confirmatory studies. This study describes a novel technique that identifies proteins dysregulated in MCL.

Abstract BLyS, recently shown to be critical for survival of normal B cells, has been found to be elevated in a number of immune disease models. A role for BLyS in the survival of malignant B cells has also been revealed and we therefore sought to identify a role for BLyS and its receptors in non-Hodgkin lymphoma (NHL). We found that tumor cells from all NHL histologic subtypes expressed one or more of 3 known receptors (BCMA, TACI, and BAFF-R) for BLyS; however, the pattern of expression was variable. We provide evidence that BLyS is expressed in tumors from patients with NHL and that BLyS levels increase as tumors transform to a more aggressive phenotype. Additionally, we provide evidence that serum BLyS levels are elevated in a subgroup of patients with NHL. In patients with de novo large B-cell lymphoma, a high BLyS level correlated with a poorer median overall survival, the presence of constitutional symptoms, and elevated values of lactic dehydrogenase. When BLyS levels were correlated with response to therapy in all patients, responding patients had a significantly lower BLyS level than those with progressive disease. In summary, we found that BLyS and its receptors represent a potentially important therapeutic target in B-cell lymphoma.

AbstractPrimary systemic amyloidosis (AL) is a fatal plasma cell disorder. Pilot data suggest survival is better in patients undergoing peripheral blood stem cell transplantation (PBSCT), but the selection process makes the apparent benefit suspect. We have reported that circulating cardiac biomarkers are the best predictors of survival outside of the transplantation setting. We now test whether cardiac troponins (cTnT and cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are prognostic in transplant recipients. In 98 patients with AL undergoing PBSCT, serum cardiac biomarkers were measured (cTnT, 98 patients; cTnI, 65 patients; and NT-proBNP, 63 patients). Elevated levels of cTnT, cTnI, and NT-proBNP were present in 14%, 43%, and 48% of patients, respectively. At 20 months median follow-up, median survival has not been reached for patients with values below the thresholds; in patients with values above the thresholds, median survival is 26.1 months, 66.1 months, and 66.1 months, respectively. Our previously reported risk systems incorporating these markers were also prognostic, notably the cTnT/NT-proBNP staging. Using this system, 49%, 38%, and 13% of patients were in stage I, stage II, and stage III, respectively. Determining levels of circulating biomarkers may be the most powerful tool for staging patients with AL undergoing PBSCT.

AbstractPrimary systemic amyloidosis (AL) is a plasma cell dyscrasia resulting in multisystem failure and death. High-dose chemotherapy with peripheral blood stem cell transplantation (PBSCT) has been associated with higher response rates and seemingly higher overall survival than standard chemotherapy. Selection bias, however, confounds interpretation of these results. We performed a case-match-control study comparing overall survival of 63 AL patients undergoing transplantation with 63 patients not undergoing transplantation. Matching criteria included age, sex, time to presentation, left ventricular ejection fraction, serum creatinine, septal thickness, nerve involvement, 24-hour urine protein, and serum alkaline phosphatase. According to design, there was no difference between the groups with respect to sex (57% males), age (median, 53 years), left ventricular ejection fraction (65%), number of patients with peripheral nerve involvement (17%), cardiac interventricular septal wall thickness (12 mm), serum creatinine (1.1 mg/dL [97.24 μmol/L]), and bone marrow plasmacytosis (8%). Sixty-six patients have died (16 cases and 50 controls). For PBSCT and control groups, respectively, the 1-, 2-, and 4-year overall survival rates are 89% and 71%; 81% and 55%; and 71% and 41%. Outside a randomized clinical trial, these results present the strongest data supporting the role of PBSCT in selected patients with AL.

In a phase 2 study, 23 patients with myelofibrosis with myeloid metaplasia were treated with imatinib mesylate at a constant dose of 400 mg/d. Treatment was held in 16 patients (70%), after 1 to 12 weeks, because of side effects (neutropenia, 6 patients; musculoskeletal pain, 5 patients; thrombocytosis, 4 patients; edema, 3 patients; diarrhea and hyperbilirubinemia, 1 patient). Including patients in whom retreatment at a reduced dose was possible, 11 patients (48%) were able to continue treatment beyond 3 months. None of the patients experienced a response in anemia, and only 2 had partial responses in splenomegaly. A greater than 50% increase in platelet count was documented in 11 (48%) patients, but not in those with baseline platelet counts of less than 100 × 109/L. In vitro, imatinib mesylate caused variable degrees of growth suppression of myeloid and erythroid progenitors that unfortunately did not translate into clinical benefit.

PURPOSE: Yttrium-90 (90Y) ibritumomab tiuxetan (Zevalin; IDEC Pharmaceutical, San Diego, CA) is an effective therapy for patients with relapsed B-cell non-Hodgkin’s lymphoma. The predominant toxicity of90Y ibritumomab tiuxetan has been myelosuppression, and concern has been expressed about the tolerability of further treatment after this therapy. The goal of this analysis was to evaluate the therapy given to patients who relapsed after90Y ibritumomab tiuxetan.PATIENTS AND METHODS: A retrospective analysis was performed on 58 patients treated at a single institution on five separate protocols that used90Y ibritumomab tiuxetan 0.4 mCi/kg. All patients had experienced disease progression after90Y ibritumomab tiuxetan treatment and received subsequent therapy. The toxicity seen in this cohort of patients with subsequent treatment regimens was analyzed and compared with that of control groups who did not receive90Y ibritumomab tiuxetan.RESULTS: The median number of subsequent therapies was two (range, one to seven). Sixteen (28%) of the 58 patients received growth factor support with subsequent chemotherapy, and two patients were treated with reduced doses because of persistent pancytopenia. Eight patients subsequently had an autologous stem-cell transplantation with stem cells collected after90Y ibritumomab tiuxetan therapy. Excluding patients hospitalized at the time of transplantation, 13 patients were hospitalized for neutropenic fever, thrombocytopenia, or both. When compared to patients who did not receive90Y ibritumomab tiuxetan, there was no significant difference in toxicity.CONCLUSION: We conclude that chemotherapy or autologous stem-cell transplantation after prior therapy with90Y ibritumomab tiuxetan is feasible and reasonably well tolerated. The toxicity with subsequent therapy seems similar to that in patients not treated with90Y ibritumomab tiuxetan.

Rituximab is a chimeric murine/human monoclonal antibody that binds to CD20 on B lymphocytes. Although binding of the Fab domain may induce apoptosis, the Fc domain recruits immune effector functions to mediate cell lysis. Interleukin-12 (IL-12) facilitates cytolytic T-cell responses, enhances the lytic activity of natural killer (NK) cells, and induces the secretion of interferon γ (IFN-γ) by both T and NK cells. Therefore, the hypothesis was considered that combining IL-12 with rituximab would augment the immune-mediated cell lysis induced by rituximab. A phase 1 study of IL-12 in combination with rituximab was conducted in 43 adults with B-cell lymphoma to determine the optimal immunologic dose of this combination. Rituximab was administered at a dose of 375 mg/m2 by intravenous infusion weekly for 4 weeks, and IL-12 was given subcutaneously twice weekly. The starting dose of IL-12 was 30 ng/kg and this was escalated to 500 ng/kg. Constitutional symptoms and liver enzyme elevations at 500 ng/kg of IL-12 were dose limiting. A greater than 20-fold increase in the serum levels of IFN-γ and a 2.5- to 5-fold increase in inducible protein 10 (IP-10) levels was seen at IL-12 doses of 100 ng/kg or greater. Objective responses occurred in 29 of the 43 patients (69%), with 8 of 11 complete responses seen at IL-12 doses of 300 ng/kg or greater. The optimal immunologic dose of IL-12 in combination with rituximab was determined to be 300 ng/kg subcutaneously twice weekly starting on day 2. These data suggest that IL-12 and rituximab is an active combination and further studies of this combination in B-cell non-Hodgkin lymphoma are warranted.

AbstractAutologous stem cell transplantation (ASCT) improves survival in patients with previously untreated multiple myeloma (MM) and relapsed, chemotherapy-sensitive, aggressive non-Hodgkin lymphoma (NHL). Lower relapse rates seen in allogeneic stem cell transplantation have been related to early absolute lymphocyte count (ALC) recovery as a manifestation of early graft-verus-tumor effect. In ASCT, the relation between ALC recovery and clinical outcomes in MM and NHL was not previously described. This is a retrospective study of patients with MM and NHL who underwent ASCT at the Mayo Clinic between 1987 and 1999. The ALC threshold was determined at 500 cells/μL on day 15 after ASCT. The study identified 126 patients with MM and 104 patients with NHL. The median overall survival (OS) and progression-free survival (PFS) times for patients with MM were significantly longer in patients with an ALC of 500 cells/μL or more than patients with an ALC of fewer than 500 cells/μL (33 vs 12 months,P < .0001; 16 vs 8 months, P < .0003, respectively). For patients with NHL, the median OS and PFS times were significantly longer in patients with an ALC of 500 cells/μL or more versus those with fewer than 500 cells/μL (not reached vs 6 months, P < .0001; not reached vs 4 months,P < .0001, respectively). Multivariate analysis demonstrated day 15 ALC to be an independent prognostic indicator for OS and PFS rates for both groups of patients. In conclusion, ALC is correlated with clinical outcome and requires further study.