Discrepancy between serological complete remission and concomitant new bone lytic lesions after infusion of escalating low doses of donor lymphocytes in multiple myeloma: a case report

Donor T-cell responses and disease progression patterns of multiple myeloma

Donor T-cells transferred after allogeneic stem cell transplantation (alloSCT) can result in long-term disease control in myeloma by the graft-versus-myeloma (GvM) effect. However, T-cell therapy may show differential effectiveness against bone marrow (BM) infiltration and focal myeloma lesions resulting in different control and progression patterns. Outcomes of 43 myeloma patients who underwent T-cell-depleted alloSCT with scheduled donor lymphocyte infusion (DLI) were analyzed with respect to diffuse BM infiltration and focal progression. For comparison, 12 patients for whom a donor search was started but no alloSCT was performed, were analyzed. After DLI, complete disappearance of myeloma cells in BM occurred in 86% of evaluable patients. The probabilities of BM progression-free survival (PFS) at 2 years after start of donor search, alloSCT and DLI, were 17% (95% confidence interval 0-38%), 51% (36-66%), and 62% (44-80%) respectively. In contrast, the probabilities of focal PFS at 2 years after start of donor search, alloSCT and DLI, were 17% (0-38%), 30% (17-44%) and 28% (11-44%), respectively. Donor-derived T-cell responses effectively reduce BM infiltration, but not focal progression in myeloma, illustrating potent immunological responses in BM with only limited effect of T-cells on focal lesions.

Efficacy of up-front treatment with a double stem cell transplantation in multiple myeloma

BACKGROUND

We report the outcome of 53 patients with multiple myeloma (MM), who received autologous stem cell transplantation (ASCT) from April 1996 to September 2004 at our institution and who survived for more than 3 months after the transplant.

METHODS

Following the first ASCT, 36 patients underwent an up-front second SCT, which consisted of either an ASCT (n = 24) or a reduced-intensity conditioning allogeneic stem cell transplant (RIST) (n = 12). Seventeen patients were given maintenance treatment.

RESULTS

Seventy-seven percent of the patients (n = 41) showed an objective response to the initial therapy prior to the first ASCT. Overall, 60.4% (32 out of 53) and 32.1% (17 out of 53) of the patients had a complete response (CR) and partial response (PR) after the first ASCT, respectively. At the time of analysis, 34 patients (64.2%) were still alive. With a median follow-up of 32 months (range 9-98), the estimated progression-free survival (PFS) and overall survival (OS) at 5 years were 17.0 and 34.9%, respectively. Multivariate analysis revealed that the second SCT, normal hemoglobin and <50% marrow plasma cells were associated with an improved PFS. A second SCT, CR to the first SCT, female gender and an absence of advanced bone lesions were associated with a better OS.

CONCLUSIONS

A second SCT is the most significant factor for an improved PFS and OS after the first ASCT (P < 0.001, respectively). Up-front double SCT is needed to improve the OS and PFS in patients with MM.

Plasmacytoma relapses in the absence of systemic progression post-high-dose therapy for multiple myeloma

Autologous (ASCT) and allogeneic stem cell transplantations (alloBMT) are well-established therapies for multiple myeloma. However, patients continue to relapse at a constant rate. We present here 15 out of 163 patients who underwent SCT and relapsed with plasmacytomas only without evidence of bone marrow disease progression (14/147 post-ASCT and 1/16 post-alloBMT). The median time from SCT to plasmacytoma relapse was 24 months. The sites of plasmacytoma included bone, skin, rectum, and testicles. Five patients were treated with local radiotherapy, while seven patients received a combination of radiotherapy and chemotherapy or thalidomide, and two patients received chemotherapy alone with or without thalidomide. The recipient of alloBMT was initially treated with VAD-chemotherapy and local radiotherapy followed by a mini-allograft from the original donor. Eleven patients died at a median of 10 months following diagnosis of the plasmacytoma. Four are still alive, 12-20 months post-plasmacytoma diagnosis. These cases of unconventional disease recurrence are likely to be seen due to sub-clinical seeding of tumour cells suggestive of the presence of an extramedullary (EM) clone of plasma cells with a high degree of chemoresistance. We also review all the available data in the literature for the optimal therapy for patients with isolated EM relapse.

Allogeneic stem cell transplantation for multiple myeloma

The sensitivity of myeloma cells to high dose chemotherapy has led to the use of allogeneic hematopoietic stem cell transplantation (HSCT) as a therapeutic modality in this disease. In addition to providing more effective chemotherapy, the transplantation of allogeneic stem cells also initiates the development of an allogeneic immune response directed against residual myeloma cells. Direct evidence for a graft vs. myeloma (GVM) effect is provided by the ability of donor lymphocyte infusion (DLI) to induce significant responses in 30-50% of patients with myeloma who have relapsed after allogeneic HSCT. Nevertheless, allogeneic stem cell transplantation is also associated with a high incidence of transplant related toxicities, including regimen-related toxicities, graft vs. host disease (GVHD) and opportunistic infections. DLI has been shown to enhance immune reconstitution after allogeneic HSCT in addition to inducing a GVM response. Current efforts are directed at reducing the toxicities associated with allogeneic HSCT, identification of the target antigens of GVM and the development of new strategies to selectively enhance the immune response to myeloma cells.

Donor lymphocyte infusions to treat hematologic malignancies in relapse after allogeneic blood or marrow transplantation

BACKGROUND

Patients with hematologic malignancies in relapse after allogeneic bone marrow transplantation can be treated by infusing leukocytes from the original stem cell donor.

METHODS

The published literature on donor lymphocyte infusion (DLI) was reviewed.

RESULTS

DLI induces complete remissions in the majority of patients with chronic myeloid leukemia (CML) in early-stage relapse and in less than 30% of patients with relapsed acute leukemia, myelodysplasia, and multiple myeloma. DLI-induced remissions of chronic phase CML are durable, but as many as half of patients with other diseases ultimately relapse. Complications of DLI include acute and chronic graft-vs-host disease (GVHD) and aplasia, which induce profound immunosuppression and susceptibility to opportunistic infections. There is a strong correlation of GVHD and disease response.

CONCLUSIONS

Novel methods of augmenting the antitumor efficacy of DLI and of dissociating the graft-vs-leukemia effect from GVHD are needed. These studies will require an improved understanding of the cellular and molecular mechanisms of alloreactivity and the development of novel agents to control the nature and intensity of the alloimmune response.

Extramedullary progression despite a good response in the bone marrow in patients treated with thalidomide for multiple myeloma

We report two patients who were treated with thalidomide for resistant multiple myeloma (MM) and developed extramedullary plasmacytomas despite a good response in the bone marrow. The first patient had progressive disease 18 months post autologous peripheral stem cell transplant. Two and a half months after the initiation of thalidomide therapy extensive new plasmacytomas of the skin and nasal mucosa appeared while the medullary response continued. The second patient was treated with thalidomide for resistant MM. Despite a medullary response he developed neurological signs compatible with cranial nerve involvement and an MRI study was suggestive of a plasmacytoma involving the sellar region. We assume that a change in the expression of some adhesion molecules on the myeloma and/or the stromal cells is responsible for this phenomenon. Treating Physicians should be aware of this phenomenon in MM patients receiving thalidomide.

Different immune reconstitution in multiple myeloma, chronic myeloid leukemia and acute myeloid leukemia patients after allogeneic transplantation of peripheral blood stem cells

In this study we compared the lymphocyte reconstitution in 13 multiple myeloma (MM), nine acute myeloid leukemia (AML) and 10 chronic myeloid leukemia (CML) patients after allogeneic G-CSF-mobilized PBSC transplantation from HLA-identical siblings. Conditioning regimens included standard total body irradiation + cyclophosphamide (CY), or busulphan + CY, whereas VP-16 was added in patients with advanced disease. Overall comparable numbers of mononuclear cells, CD34+ cells and CD3+ T cells were infused in each group. A significantly higher CD3+ T cell number was observed in MM and AML than in CML patients 1 month after transplant. However, MM patients showed a faster and better recovery of CD4+ T cells than both AML and CML patients at 3 months (P = 0.01 and P = 0.01, respectively) and 12 months (P = 0.01 vs AML, while P = NS vs CML) after transplant, and had a CD4:CD8 ratio > 1 with a median CD4+ T cell value > 400/microl 1 year after transplant. Development of acute graft-versus-host disease (GVHD) did not affect CD4:CD8 ratios but patients who experienced acute GVHD > grade I had lower CD4+ and CD8+ T cell numbers at all time points. However, after excluding patients with GVHD > grade I, MM patients still showed a significantly higher CD4+ T cell value than patients with myeloproliferative diseases 1 year after transplant. These findings suggest that although allogeneic PBSC transplantation induces rapid immune reconstitution, different kinetics may occur among patients with hematological malignancies. In particular, the rapid reconstitution of CD4+ T cells in MM patients may contribute to the low transplant-related mortality achieved in this disease.

Molecular monitoring of minimal residual disease in patients in long-term complete remission after allogeneic stem cell transplantation for multiple myeloma

In the present study, we used a polymerase chain reaction–based (PCR-based) strategy to retrospectively analyze the presence of residual myeloma cells in serial posttransplant bone marrow samples obtained from 13 patients in remission after allogeneic hemopoietic stem cell transplantation (allo SCT). For this purpose, patient-specific primers were generated from complementarity determining regions 2 and 3 of the rearranged IgH gene. The level of sensitivity of the PCR-based assay ranged from 1 in 105 to 1 in 106 normal marrow cells. Following transplantation, 9 of 12 patients who attained stringently defined complete remission (CR) remained persistently PCR− for a median of 36 months, and 4 of the patients remained PCR− up to the latest analysis, which was performed at 48, 72, 72, and 120 months, respectively, after allo SCT. None of the patients in the PCR− subgroup experienced a disease relapse, and only 1 of 4 PCR+ patients experienced a relapse. It is concluded that allo SCT has the potential ability to induce sustained serological and molecular CR in selected patients with multiple myeloma.

Molecular monitoring of minimal residual disease in patients in long-term complete remission after allogeneic stem cell transplantation for multiple myeloma

In the present study, we used a polymerase chain reaction–based (PCR-based) strategy to retrospectively analyze the presence of residual myeloma cells in serial posttransplant bone marrow samples obtained from 13 patients in remission after allogeneic hemopoietic stem cell transplantation (allo SCT). For this purpose, patient-specific primers were generated from complementarity determining regions 2 and 3 of the rearranged IgH gene. The level of sensitivity of the PCR-based assay ranged from 1 in 105 to 1 in 106 normal marrow cells. Following transplantation, 9 of 12 patients who attained stringently defined complete remission (CR) remained persistently PCR− for a median of 36 months, and 4 of the patients remained PCR− up to the latest analysis, which was performed at 48, 72, 72, and 120 months, respectively, after allo SCT. None of the patients in the PCR− subgroup experienced a disease relapse, and only 1 of 4 PCR+ patients experienced a relapse. It is concluded that allo SCT has the potential ability to induce sustained serological and molecular CR in selected patients with multiple myeloma.

Molecular remission after allogeneic or autologous transplantation of hematopoietic stem cells for multiple myeloma

PURPOSE

To assess the clinical relevance of minimal residual disease (MRD) in patients with multiple myeloma (MM), 50 patients were monitored while they were in complete clinical remission (CCR) after autologous or allogeneic stem-cell transplantation.

PATIENTS AND METHODS

Stringent molecular monitoring using clonal markers based on rearranged immunoglobulin heavy-chain genes was performed in 44 of 50 MM patients in CCR. Molecular clinical remission (MCR) was defined as more than one consecutive negative polymerase chain reaction (PCR) test result.

RESULTS

Twelve (27%) of 44 molecularly monitored patients achieved MCR; four of the 12 became PCR-positive, and one of these four relapsed. In comparison with patients who did not achieve MCR, patients who achieved MCR had a significantly lower relapse rate (41% v 16%; P <.05) and longer relapse-free survival (35 v 110 months; P <.005). Fourteen of 26 patients in CCR who had received allografts were evaluated on a molecular basis: seven (50%) of the 14 achieved MCR and did not relapse; one of the seven remaining patients relapsed. Thirty of 47 patients in CCR who received autografts were evaluated on a molecular basis: five (16%) of the 30 achieved MCR; two of these five became PCR-negative, and one of these two relapsed. Ten of the 25 remaining patients later relapsed. For these nonrandomized groups, the higher MCR rate after allograft procedures was statistically significant (P <.01; Fisher's exact test).

CONCLUSION

MCR can be obtained in a relatively high proportion of MM patients who have achieved CCR after undergoing allograft procedures and in a smaller fraction of patients after undergoing autograft procedures. In approximately one fourth of MM patients who achieve CCR after transplantation, it may be possible to keep the disease burden constantly below the PCR threshold. Because MCR was associated with prolonged relapse-free survival, these patients could have a relatively favorable clinical outcome.