Rituximab maintenance after autologous stem cell transplantation prolongs response duration in non-naive rituximab follicular lymphoma patients: a single institution experience.

We retrospectively evaluated the role of rituximab (R) in maintenance treatment after autologous stem cell transplantation performed in patients with relapsed follicular lymphoma. We compared the outcome of 67 follicular lymphoma (FL) patients according to the use of rituximab maintenance (RM) or not. All patients received rituximab plus chemotherapy before autologous stem-cell transplantation (ASCT). Patients received median of two lines of prior therapy. The RM schedule was one injection of rituximab every 3 months for 2 years. Median follow-up is 4.6 years. The 3-year progression-free survival (PFS) after ASCT was 86 % with RM vs. 46 % without (p = 0.0045). Median is not reached in the RM arm vs. 31 months in non-RM arm. The 3-year OS was 96 % with RM vs. 78 % without (p = 0.059). The present monocentric study shows that 2 years of RM after ASCT significantly increases response duration for non-naive rituximab relapsed FL patients compared with observation.

Upfront allogeneic stem-cell transplantation for patients with nonlocalized untreated peripheral T-cell lymphoma: an intention-to-treat analysis from a single center.

BACKGROUND: Peripheral T-cell lymphomas (PTCLs) are rare and heterogeneous diseases with dismal outcome when treated with chemotherapy alone. Because allogeneic stem-cell transplantation (allo-SCT) can cure relapse/refractory patients, we hypothesized that upfront allo-SCT may provide a better outcome. Therefore, all patients that presented with advanced PTCL in our institution at diagnosis were scheduled to undergo upfront allo-SCT after induction chemotherapy. PATIENTS AND METHODS: The aim of the present work was to assess the feasibility and toxicity of upfront allo-SCT. From 2004 to 2012, 49 newly diagnosed PTCL patients were scheduled to receive upfront allo-SCT. A human leukocyte antigen-matched donor was found for 42 patients: related to the patient in 15 cases, unrelated in 20 cases, and suitable cord blood units were used in 7 cases. RESULTS: After induction chemotherapy, 17 patients reached complete remission and 29 (60%) proceeded to upfront allo-SCT. For all patients, the 1 and 2-year overall survival (OS) rates were 59% [95% confidence interval (CI) 47-75] and 55% (95% CI 43-71), respectively. The most frequent reason we did not proceed to allo-SCT was disease progression or insufficient response after induction. For transplanted patients, the 1- and 2-year OS were 76% (95% CI 62-93) and 72.5% (95% CI 58-91), respectively. Toxicity-related mortality (TRM) 1 year after allo-SCT was only 8.2% (95% CI 0-18.5). The 2-year progression-free survival (PFS) rate of patients who did not proceed to allo-SCT (n = 20) was below 30%. The disease status at the time of transplantation was a strong predictive marker for both PFS and OS in transplant patients. CONCLUSIONS: Upfront allo-SCT in PTCLs is feasible with low TRM, and it provides long-term disease control. However, one-third of patients remain chemo-refractory and, thus, new therapeutic approaches are warranted. The role of upfront allo-SCT compared with other therapeutic approaches in PTCLs requires investigation in randomized studies.

Efficacy of bendamustine in relapsed/refractory myeloma patients: results from the French compassionate use program.

One hundred and ten patients with multiple myeloma were treated with bendamustine as part of a French compassionate use program. To receive bendamustine, patients had to present with relapsed or refractory disease after prior therapies that had to include alkylators, steroids, IMiDs and bortezomib. The median number of bendamustine cycles administered was 4 (1-13). The overall response rate (≥ partial response) was 30%, including 2% complete responses. The median progression-free and overall survival for the entire cohort were 9.3 and 12.4 months, respectively. In this series of patients with advanced disease, both the response rate and the duration of response are encouraging and indicate that bendamustine presents a feasible option, which should be considered for the treatment of relapsed/refractory patients.

18F-fluorodeoxyglucose-positron emission tomography before, during and after treatment in mature T/NK lymphomas: a study from the GOELAMS group.

BACKGROUND: In non-cutaneous T-cell/natural killer (T/NK) lymphomas, the prognostic value of (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) during or after therapy is unknown. PATIENTS AND METHODS: In this retrospective study, 54 T/NK lymphoma patients were assessed using FDG-PET before (n = 40), during (n = 44) and/or after therapy (n = 31). RESULTS: FDG-PET showed an abnormal FDG uptake in all cases. Interim FDG-PET was negative in 25 of 44 cases. After completion of therapy, 19 of 31 patients reached complete remission with negative FDG-PET. In ALK+ anaplastic large cell lymphomas, the 4-year progression-free survival (PFS) was 80% and the negative predictive value of post-therapy FDG-PET was 83% (n = 9). In ALK- T/NK lymphomas, the 4-year PFS was 59% for patients with a negative interim FDG-PET versus 46% for patients with a positive interim FDG-PET (P = 0.28, n = 35). Similarly, there was no statistical difference in 4-year PFS between negative and positive post-therapy FDG-PET in these lymphomas (51% and 67%, respectively, P = 0.96). The 4-year cumulative incidence of relapse from a negative post-therapy FDG-PET was 53% in ALK- T/NK lymphomas. CONCLUSIONS: Although T/NK lymphomas are FDG-avid at diagnosis, a negative interim or post-therapy FDG-PET does not translate into an improved PFS in ALK- T/NK lymphomas.

Impact of high-dose chemotherapy followed by auto-SCT for positive interim [18F] FDG-PET diffuse large B-cell lymphoma patients.

[(18)F] fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is increasingly used for response assessment in diffuse large B-cell lymphoma (DLBCL). A positive interim FDG-PET was shown to be associated with an unfavorable outcome in high-grade non-Hodgkin's lymphomas. For positive interim FDG-PET patients, the question of increasing the intensity of treatment using high-dose chemotherapy followed by auto-SCT (HDC-ASCT) remains unanswered. We retrospectively analyzed the prognostic value of FDG-PET in 42 DLBCL patients who were systematically evaluated at time of diagnosis, before and after HDC-ASCT. Of note, HDC-ASCT was part of the initial treatment strategy, while FDG-PET results did not influence the treatment approach. Results and outcome were analyzed according to FDG-PET results before and after HDC-ASCT. Patients were classified into three groups according to FDG-PET results before and after HDC-ASCT: those who were negative before and after (-/-; n=25), positive before and negative after (+/-; n=9) or positive before and after (+/+; n=8). The median follow-up was 34.5 (range, 19-74) months. The median EFS was significantly lower for the +/+ group (27.4 months) as compared with other groups (median not reached; P=0.0001). More importantly, there was no difference in term of EFS between the -/- group compared with the +/- group. These results suggest that HDC-ASCT can significantly improve the bad prognosis, otherwise indicated by a positive interim FDG-PET.

PCR detection of residual Bcl-2/IgH-positive cells after high-dose therapy with autologous stem cell transplantation is a prognostic factor for event-free survival in patients with low-grade follicular non-Hodgkin's lymphoma.

This study was designed to evaluate the results of high-dose therapy followed by purged autologous stem cell transplantation (ASCT) for patients with low-grade follicular non Hodgkin's lymphoma (LGFL), and the prognostic significance of PCR detection of residual Bcl-2/IgH-positive cells after ASCT. Between 1992 and 1998, 49 patients with LGFL received total body irradiation and high-dose cyclophosphamide followed by purged ASCT. PCR amplification of the Bcl-2/IgH rearrangement was performed at diagnosis, on stem cell collections before and after purging and on bone marrow and blood samples after ASCT. With a median follow-up of 76 months (37-103) 34 patients remain alive and event-free. A total of 20 patients had disease recurrence, three patients developed secondary myelodysplastic syndrome (MDS). In all, 11 patients died; 10 deaths were because of recurrent disease, one because of MDS. Kaplan-Meier estimates of event-free survival (EFS) and overall survival (OS) at 5 years were 65% (+/-7%) and 77% (+/-6%), respectively. Patients who achieved a sustained molecular complete response (CR) had a lower risk of disease recurrence and experienced significantly longer EFS (93% (+/-6%) vs 11% (+/-7%) P=0.0008) and OS (100 vs 55% (+/-12%) P=0.0057). In conclusion, myeloablative therapy followed by purged ASCT may induce long EFS in patients with LGFL. The achievement of sustained molecular CR after ASCT improves EFS and OS.

Anti-cancer therapy using dendritic cells and apoptotic tumour cells: pre-clinical data in human mesothelioma and acute myeloid leukaemia.

We have recently reported in an experimental model, that treatments based on the injections of dendritic cells which had phagocytosed apoptotic bodies derived from tumour cells were particularly effective in the cure of tumour-bearing animals. We proposed that systems using processing and presentation of antigenic molecules from antigen-presenting cells primed with apoptotic bodies can offer new opportunities in anti-cancer treatment. We first established the technical conditions for purification, characterisation and production of tumour cells isolated from fresh pleural liquid or blood. Then we compared efficacy of different apoptotic inducers agents on the cancer cells in culture. The apoptotic tumour cells were purified, characterised and maintained in coculture with monocytes-derived immature dendritic cells. We subsequently investigated the effect of the maturation process on phagocytosis of apoptotic bodies. We have shown that whatever the nature of the apoptotic cells they are phagocytosed by the dendritic cells which were efficiently matured using the combination of TNFalpha+Poly I:C. Furthermore, we demonstrated that the generation of the mature dendritic cells pulsed with apoptotic tumour cells, successfully generated CD4(+) (Th1) and CD8(+) (CTL) cells. All the experimental procedures that we have used were developed with clinical use in mind, using Good Manufacturing Products. We are presently investigating the feasibility of such a "vaccine" for the treatment of asbestos mesothelioma or acute myeloid leukaemia.

Long-term results (12 years) of high-dose therapy in 127 patients with de novo multiple myeloma.

This report describes the long-term outcome of a cohort of 127 de novo multiple myeloma patients treated with at least one course of high-dose therapy (HDT) in a single institution between June 1985 and December 1995, for whom the minimum follow-up duration for survivors is 6 years. The 12-year overall survival (OS) and event-free survival (EFS) rates are 24.9% and 3.1%, respectively, and the median survival and EFS are 49 and 17 months, respectively. Only four patients are alive and disease-free 79, 90, 132 and 153 after the first HDT, respectively. Three of them received a subsequent allogeneic bone marrow transplantation. Three factors significantly influence OS in this series: B2M at diagnosis, age, and the completion of a second HDT. The 10-year survival is 18.9% for the group of patients with B2M level >3 mg/l at diagnosis as compared with 41% for patients with B2M < or =3, with a median survival of 31 months vs 73 (P = 0.01). The 10-year survival is 23.4% for the group of patients aged >55 years as compared with 36.5% for patients aged <55 years, with a median survival of 34.5 months vs 70.5 (P = 0.04). The 10-year survival is 20.4% for the group of patients who did not receive a second HDT as compared with 35.2% for patients who completed a second HDT, with a median survival of 29 months vs 70 (P = 0.02). In this study we show that some patients treated with HDT experience durable remission and prolonged survival. This survival is significantly influenced by age (< or =55 years), B2M at diagnosis (< or =3 mg/l) and by the completion of two cycles of HDT.

Front-line high-dose therapy with autologous stem cell transplantation for high risk Hodgkin's disease: comparison with combined-modality therapy.

This retrospective study compares high-dose therapy (HDT) with autologous stem cell transplantation and combined-modality treatment (CT) as a first-line therapy for Hodgkin's disease (HD) for patients with both a clinical stage (CS) IV and/or a mediastinal mass > or =0.45 of the thoracic diameter (MM > or =0.45) at diagnosis, and an incomplete response after the first-line chemotherapy. Data on 42 grafted patients (GP) in Nantes Hospital, France and on 108 combined-modality treated patients (CTP) from two protocols of the GOELAMS group, France (POF 81 and H90) was analyzed. Both groups were comparable except for pulmonary disease in excess in the grafted group (P = 0.01). Among GP, 95% were in complete response at the end of first-line treatment and 77% among CTP. Median follow-up was 53 months (range, 7 to 128 months) for GP and 88 months (range, 25 to 181 months) for CTP. The 5-year freedom from progression (FFP) and event-free survival (EFS) rates were better for GP (87% vs 55% for FFP: P = 0.0004 and 81% vs 51% for EFS: P = 0.0004) whereas the overall survival (OS) rates did not differ significantly (85% for GP vs 71% for CTP: P = 0.06). Similar results were obtained for the groups with a response > or =50% after initial chemotherapy: 91% vs 65% for FFP, P = 0.01; 87% vs 61% for EFS, P = 0.02; and 92% vs 77% for OS, P = 0.2; and for the groups with a response <50%: 80% vs 22% for FFP, P = 0.0003; 72% vs 13% for EFS, P = 0.0001; and 76% vs 46% for OS, P = 0.04. This study shows a better control of the disease with HDT.

Longitudinal study of bacterial, viral, and fungal infections in adult recipients of bone marrow transplants.

The epidemiology of infections was studied in a retrospective cohort of 446 recipients of bone marrow transplants (BMTs; 92 of which were allogeneic and 354 of which were autologous) during 1993--1996. Infections that were microbiologically documented in 274 recipients included bacteremia, urinary tract infections, cytomegalovirus viremia, fungemia, invasive aspergillosis, and catheter-related infections. During the period of neutropenia, no differences were found between recipients of allogeneic BMTs and recipients of autologous BMTs with regard to the incidence and the nature of infection. After patients underwent engraftment, bacteremia, cytomegalovirus viremia, and invasive aspergillosis were significantly more common in recipients of allogeneic BMTs than in recipients of autologous BMTs. Deaths caused by infection were uncommon and were mainly the result of invasive aspergillosis. Therefore, empirical antimicrobial therapy should be the same for recipients of both allogeneic and autologous BMTs during the period of neutropenia; after engraftment, more attention should be paid to the risk of infection in allogeneic BMT recipients, particularly with regard to detection and prevention of invasive aspergillosis.

[Autologous peripheral blood selected CD34+ cell transplantation in the treatment of multiple myeloma].

OBJECTIVE: To investigate the clinical impact of CD(34)(+) cell selected autologous peripheral blood stem cell transplantation (APBSCT) in multiple myeloma (MM). METHODS: The hematopoietic recovery time, treatment efficacy, survival rate, transplantation related morbidity and the cost were compared between 21 MM patients receiving CD(34)(+) APBSCT and 21 MM patients receiving unselected APBSCT. The age and beta(2) microglobulin level at diagnosis and disease status at the time of transplantation were similar in the two groups. The induction treatment and conditioning regimen were the same. RESULTS: Significantly lower CD(34)(+) cells were infused in the selected group as compared with the control group: 2.2 (0.5 - 14.3) x 10(6)/kg vs 9.4 (1.1 - 15.0) x 10(6)/kg, (P < 0.001). The median times to neutrophil >or= 0.5 x 10(9)/L and platelet >or= 20 x 10(9)/L were 10 and 9 days for the selected group, and 9.5 (P = 0.357) and 4.5 days (P = 0.005) for the control group, respectively. Response rates were similar in both groups (85.7% for the selected group vs 90.4% for the control group). Three year disease-free survival (32% for the selected group vs 39% for the control group) and overall survival rates (85% for the selected group vs 79% for the control group) were not significantly different. Furthermore, unselected APBSCT could reduce the cost for the transplantation. CONCLUSION: It shows that CD(34)(+) cell selected autologous transplantation is more expensive and does not improve the clinical outcome of patients with MM.

Lack of benefit of CD34+ cell selected over non-selected peripheral blood stem cell transplantation in multiple myeloma: results of a single center study.

In order to determine the clinical impact of CD34+ cell selected autologous transplantation in multiple myeloma (MM), we have performed a retrospective case-controlled analysis comparing 21 MM patients receiving high-dose melphalan and autologous transplantation with CD34+ peripheral blood stem cells (PBSC) as front-line therapy to 21 control patients receiving unselected products. Case matching was performed using the following criteria: age and beta2-microglobulin at diagnosis and disease status at the time of transplantation. Both cohorts were homogeneous in term of induction treatment and conditioning regimen. Patients were collected for CD34+ selection after priming with G-CSF alone. Significantly fewer CD34+ cells/kg were infused to patients in the selected group as compared to patients in the control group: 2.2 (range 0.5-14.3) vs 9.4 (range 1.1-15) (P < 0.001). The median time to neutrophil recovery > or =0.05 x 10(9)/l was 10 days for the CD34+ group and 9.5 days for the control group (P = 0.357). The median time to platelet recovery > or = 20 x 10(9)/l was 9 days for the CD34+ group and 4.5 days for the control group (P = 0.005). Response rates were comparable in both groups (85.7% in the CD34+ group vs 90.4% in the control group). At 3 years, event-free survival (32% in the CD34+ group vs 39% in the control group) and overall survival (85% in the CD34+ group vs 79% in the control group) were not significantly different. Finally, use of unselected products dramatically reduced the cost of the transplantation procedure. This study shows that CD34+ cell selected autologous transplantation is more expensive than transplantation with unselected products and does not improve the clinical outcome of patients with MM.

A combination of anti-interleukin 6 murine monoclonal antibody with dexamethasone and high-dose melphalan induces high complete response rates in advanced multiple myeloma.

To improve the complete response (CR) rate in advanced multiple myeloma (MM) without increasing the toxicity of high-dose therapy, we have used a new conditioning regimen. A combination of BE-8 [an anti-interleukin 6 (IL-6) murine monoclonal antibody] and dexamethasone followed by high-dose melphalan (220 mg/m2) and autologous stem cell transplantation was used to treat a series of 16 patients with advanced multiple myeloma. A strong inhibition of IL-6 activity evaluated by quantification of C-reactive protein was observed in all patients and was correlated with the high CR rate achieved with this combination therapy.

Monosomy 13 is associated with the transition of monoclonal gammopathy of undetermined significance to multiple myeloma. Intergroupe Francophone du Myélome.

Chromosomal abnormalities are present in most (if not all) patients with multiple myeloma (MM) and primary plasma cell leukemia (PCL). Furthermore, recent data have shown that numerical chromosomal changes are present in most individuals with monoclonal gammopathy of undetermined significance (MGUS). Epidemiological studies have shown that up to one third of MM may emerge from pre-existing MGUS. To clarify further possible stepwise chromosomal aberrations on a pathway between MGUS and MM, we have analyzed 158 patients with either MM or primary PCL and 19 individuals with MGUS using fluorescence in situ hybridization (FISH). Our FISH analyses were designed to detect illegitimate IGH rearrangements at 14q32 or monosomy 13. Whereas translocations involving the 14q32 region were observed with a similar incidence (60%) in both conditions, a significant difference was found in the incidence of monosomy 13 in MGUS versus MM or primary PCL. It was present in 40% of MM/PCL patients, but in only 4 of 19 MGUS individuals. Moreover, whereas monosomy 13 was found in the majority of plasma cells in MM, it was observed only in cell subpopulations in MGUS. It is noteworthy that, in a group of 20 patients with MM and a previous MGUS history, incidence of monosomy 13 was 70% versus 31% in MM patients without a known history of MGUS (P =.002). Thus, this study highlights monosomy 13 as correlated with the transformation of MGUS to overt MM and may define 2 groups of MM with possible different natural history and outcome, ie, post-MGUS MM with a very high incidence of monosomy 13 and de novo MM in which other genetic events might be involved. Serial analyses of individuals with MGUS will be needed to validate this model.

P53 deletion is not a frequent event in multiple myeloma.

Recently a high incidence of interstitial deletion of the P53 locus has been reported in multiple myeloma (MM) patients. Considering the importance of such an event, we analysed 79 patients with advanced-stage disease using fluorescence in situ hybridization (FISH). Strikingly, we found only 7/79 patients with a P53 deletion. In order to rule out any differences in probe selection, we reanalysed all the patients with the same probe as that used in a previous study, and confirmed the low incidence of P53 deletion (7/79, 9%). The only explanation is a difference in hybridization efficiency. Since hybridization is far less efficient on malignant plasma cells than on other bone marrow cells we suggest that this poor hybridization efficiency may lead to a false P53 deletion.

V(H) gene analysis of IgM-secreting myeloma indicates an origin from a memory cell undergoing isotype switch events.

IgM-secreting plasma cell tumors are rare variants of typical isotype-switched multiple myeloma with a similar disease outcome. To probe the origin and clonal history of these tumors, we have analyzed V(H) gene sequences in 6 cases. Potentially functional tumor-derived V(H) genes were all derived from V(H)3, with the V(3-7) gene segment being used by 4 of 6. All were somatically mutated, with a mean deviation from germline sequence of 5.2% (range, 3.1% to 7.1%). The distribution of replacement mutations was consistent with antigen selection in 4 of 6 cases, and no intraclonal heterogeneity was observed. Clonally related switched isotype transcripts were sought in 4 cases, and Cgamma transcripts with tumor-derived CDR3 sequence were identified in 2 of 4. These findings indicate that IgM-secreting myelomas are arrested at a postfollicular stage at which somatic mutation has been silenced. Isotype switch variants show the cell of origin to be at the IgM to IgG switch point. These features indicate that the final neoplastic event has occurred at a stage immediately before that of typical isotype-switched myeloma. One possibility is that IgM myeloma involves the previously identified precursor cell of typical myeloma.

[Pseudallescheria boydii osteoarthritis in a patient with acute lymphoblastic leukemia: a case report]. / Ostéoarthrite à Pseudallescheria boydii chez un patient porteur de leucémie aiguë lymphoblastique: à propos d'un cas.

INTRODUCTION: The outcome of neutropenic patients with Pseudallescheria boydii infection is poor. EXEGESIS: We report the first case of Pseudallescheria boydii hip arthritis in a patient treated for acute lymphoblastic leukemia. In vitro susceptibility testing showed that the strain was resistant to amphotericin B, fluorocytosine and nystatin, but susceptible to itraconazole. The patient received oral itraconazole (600 mg/day) and clinical symptoms initially resolved. Two months later, after a course of chemotherapy and high-dose steroids while receiving oral itraconazole treatment, the patient developed fever, skin lesions and disseminated lung infiltrates due to Pseudallescheria boydii and finally died. CONCLUSION: This case illustrates the severity of fungal infections due to Pseudallescheria boydii despite a presumably well-conducted antifungal therapy.

Melphalan 220 mg/m2 followed by peripheral blood stem cell transplantation in 27 patients with advanced multiple myeloma.

Twenty-seven patients with advanced multiple myeloma received high-dose therapy with 220 mg/m2 i.v. melphalan (HDM220) followed by autologous stem cell transplantation. At the time of HDM220, nine patients had primary refractory disease and 18 were in relapse after having responded to prior high-dose therapy. No toxic deaths were observed. The major adverse side-effect was grade 4 mucositis in 63% of patients. Two patients experienced reversible paroxysmal atrial fibrillation after HDM220. For the whole group of patients, the actuarial 3-year overall survival (OS) and event-free survival (EFS) are 36.1 and 16.9%, respectively. The probability of OS and EFS was significantly lower in patients treated for refractory relapse (22.9 and 0% at 2 years, respectively) as compared to primary refractory patients (66.7 and 64.3% at 2 years, respectively) or patients treated for chemosensitive relapse (42.9% at 2 years) (P = 0.0001). Low beta2-microglobulin and CRP levels at the time of HDM220 were associated with a better OS and EFS. Our data suggest that HDM220 followed by ASCT should be considered in patients with primary refractory disease or chemosensitive disease relapsing after prior intensive therapy.

Differential expression of Bcl-2 in human plasma cell disorders according to proliferation status and malignancy.

Multiple myeloma (MM) is a malignancy characterized by a very slow proliferation of malignant plasma cells leading to their accumulation within the bone marrow. This suggests that resistance to apoptosis may play a critical role both in the pathogenesis and resistance to treatment of MM. Bcl-2 is a key protein for the regulation of apoptosis. However, it has been shown that this protein also regulates the state of proliferation. In the current study, we show that malignant plasma cells from both the bone marrow and peripheral blood express high levels of Bcl-2 and are slowly proliferating cells. In contrast, myeloma cells from extramedullary sites (ie pleural effusion, ascitis, mammary and gastric plasmacytoma) express Bcl-2 weakly while being highly proliferative. Normal non-dividing bone marrow plasma cells express high levels of Bcl-2 protein. In contrast, four highly proliferative reactive plasmacytosis express weak levels of Bcl-2. We conclude that there is an inverse correlation between Bcl-2 expression and the proliferation rate of both normal and malignant plasma cells. These data may be explained by the double function of Bcl-2, ie its well known function as an anti-apoptotic molecule and its intriguing function as an inhibitory molecule of cell proliferation.

High incidence of cryptic translocations involving the Ig heavy chain gene in multiple myeloma, as shown by fluorescence in situ hybridization.

Cytogenetic studies have shown rearrangements of the Ig heavy chain (IGH) gene at 14q32 in 10-60% of patients with multiple myeloma (MM) or primary plasma cell leukemia (PCL). Analysis of MM patients and human myeloma cell lines (HMCL) using interphase fluorescence in situ hybridization (FISH) and molecular techniques has shown IGH rearrangements in 75% of MM cases and in up to 100% of HMCL. A review of the literature revealed at least 18 different partner chromosomal regions. To investigate whether some of these translocations were recurrent and possibly to identify new partner regions, we developed a set of FISH probes to detect every IGH recombination. We analyzed 28 MM and 4 primary PCL patients with abnormal karyotypes and 12 HMCL. Whereas conventional cytogenetics detected a 14q32 abnormality in only 15% of the patients, FISH detected it in 47% of patients and in 75% of HMCL. The partner chromosome was identified in 10 of 15 patients with a 14q32 rearrangement. Interestingly, the same t(4; 14)(p16;q32) was detected in five patients and three HMCL, i.e., 33% of patients and HMCL with an IGH rearrangement. New partner chromosomal regions have also been identified, i.e., 9p13, 12p11, 12p13, and Xq28, besides the previously reported 8q24, 11q13, 12q24, and 16q24 rearrangements. The genes involved in these new translocations are not known, except for 9p13, where PAX5 was shown to be the partner gene. We conclude that: I) IGH recombinations are frequent but not constant in MM, 2) these rearrangements often occur through cryptic translocations, and 3) the t(4;14)(p16;q32) is one of the most frequent translocations, but many other chromosomal regions may be involved.