Citations

Autologous stem cell transplantation as a platform for multiple myeloma treatment is the standard of care for patients who can safely withstand the procedure. Before novel agents were introduced, one-third to one-half of patients did not achieve partial response at transplantation. Previous medical literature has shown that in this past era, absence of initial response to induction therapy had no impact on progression-free survival and overall survival after high-dose therapy. Lack of response to initial induction did not preclude a good response after stem cell transplantation. With the introduction of novel agents—immunomodulatory drugs and proteasome inhibitors—response rates with initial therapy are now between 70% and 100%. This retrospective study analyzes progression-free survival and overall survival in patients who do not have a partial response (never responded or progressed during continuous therapy) after induction therapy with a regimen that contains thalidomide or lenalidomide. Unlike patients in reports published previously—before immunomodulatory drugs—patients who do not achieve partial remission have a significantly shorter overall survival from transplantation (73.5 vs 30.4 months) and a shorter progression-free survival (22.1 vs 13.1 months; P < .001). Absence of a response to induction therapy with thalidomide or lenalidomide predicts a poorer outcome after high-dose therapy.

OBJECTIVE—Type 1 and type 2 diabetes are characterized by an ∼98 and ∼65% loss of pancreatic β-cells, respectively. Efforts to reverse either form of diabetes increasingly focus on the possibility of promoting β-cell replacement and/or regeneration. Islet transplantation has been explored, but it does not provide long-term insulin independence. One possible source of β-cell regeneration is hematopoietic stem cells. In mice, there are conflicting data as to whether hematopoietic stem cells contribute to pancreatic β-cells. We sought to establish whether hematopoietic stem cells (derived from adult donors) transdifferentiate into pancreatic β-cells in adult humans. RESEARCH DESIGN AND METHODS—We addressed this in 31 human pancreata obtained at autopsy from hematopoietic stem cell transplant recipients who had received their transplant from a donor of the opposite sex. RESULTS—Whereas some donor-derived cells were observed in the nonendocrine pancreata, no pancreatic β-cells were identified that were derived from donor hematopoietic stem cells, including two cases with type 2 diabetes. CONCLUSIONS—We conclude that hematopoietic stem cells derived from adult donors contribute minimally to pancreatic β-cells in nondiabetic adult humans. These data do not rule out the possibility that hematopoietic stem cells contribute to pancreatic β-cells in childhood or in individuals with type 1 diabetes.

Abstract JAK2V617F and MPLW515L/K are myeloproliferative disorder (MPD)-associated mutations. We genotyped 552 individual hematopoietic colonies obtained by CD34+ cell culture from 16 affected patients (13 JAK2V617F and 3 MPLW515L/K) to determine (a) the proportion of colonies harboring a particular mutation in the presence or absence of cytokines, (b) the lineage distribution of endogenous colonies for each mutation, and (c) the differences (if any) in the pattern of mutation among the various MPDs, as established by genotyping of individual colonies. Genotyping analysis revealed cohabitation of mutation-negative and mutation-positive endogenous colonies in polycythemia vera as well as other MPDs. Culture of progenitor cells harboring MPLW515L/K yielded virtually no endogenous erythroid colonies in contrast to JAK2V617F-harboring progenitor cells. The mutation pattern (i.e., relative distribution of homozygous, heterozygous, or wild-type colonies) was not a distinguishing feature among the MPDs, and MPLW515 mutations were detected in B and/or T lymphocytes in all three patients tested. These observations suggest that clonal myelopoiesis antedates acquisition of JAK2V617F or MPLW515L/K mutations and that the latter is acquired in a lympho-myeloid progenitor cell. Disclosure of potential conflicts of interest is found at the end of this article.

Abstract Recently, a gain-of-function MPL mutation, MPLW515L, was described in patients with JAK2V617F-negative myelofibrosis with myeloid metaplasia (MMM). To gain more information on mutational frequency, disease specificity, and clinical correlates, genomic DNA from 1182 patients with myeloproliferative and other myeloid disorders and 64 healthy controls was screened for MPL515 mutations, regardless of JAK2V617F mutational status: 290 with MMM, 242 with polycythemia vera, 318 with essential thrombocythemia (ET), 88 with myelodysplastic syndrome, 118 with chronic myelomonocytic leukemia, and 126 with acute myeloid leukemia (AML). MPL515 mutations, either MPLW515L (n = 17) or a previously undescribed MPLW515K (n = 5), were detected in 20 patients. The diagnosis of patients with mutant MPL alleles at the time of molecular testing was de novo MMM in 12 patients, ET in 4, post-ET MMM in 1, and MMM in blast crisis in 3. Six patients carried the MPLW515L and JAK2V617F alleles concurrently. We conclude that MPLW515L or MPLW515K mutations are present in patients with MMM or ET at a frequency of approximately 5% and 1%, respectively, but are not observed in patients with polycythemia vera (PV) or other myeloid disorders. Furthermore, MPL mutations may occur concurrently with the JAK2V617F mutation, suggesting that these alleles may have functional complementation in myeloproliferative disease.

AbstractWe present results of 2 similarly designed but separate phase 2 studies involving single-agent lenalidomide (CC-5013, Revlimid) in a total of 68 patients with symptomatic myelofibrosis with myeloid metaplasia (MMM). Protocol treatment consisted of oral lenalidomide at 10 mg/d (5 mg/d if baseline platelet count < 100 × 109/L) for 3 to 4 months with a plan to continue treatment for either 3 or 24 additional months, in case of response. Overall response rates were 22% for anemia, 33% for splenomegaly, and 50% for thrombocytopenia. Response in anemia was deemed impressive in 8 patients whose hemoglobin level normalized from a baseline of either transfusion dependency or hemoglobin level lower than 100 g/L. Additional treatment effects in these patients included resolution of leukoerythroblastosis (4 patients), a decrease in medullary fibrosis and angiogenesis (2 patients), and del(5)(q13q33) cytogenetic remission accompanied by a reduction in JAK2V617F mutation burden (1 patient). Grade 3 or 4 adverse events included neutropenia (31%) and thrombocytopenia (19%). We conclude that lenalidomide engenders an intriguing treatment activity in a subset of patients with MMM that includes an unprecedented effect on peripheral blood and bone marrow abnormalities.

Abstract POEMS syndrome is characterized by peripheral neuropathy (PN), a clonal plasma cell disorder (PCD), organomegaly, endocrinopathy, skin changes, edema, sclerotic bone lesions, and thrombocytosis. Based on the improved response rates observed with peripheral blood stem cell transplantation (PBSCT) in patients with other PCDs, autologous PBSCT may be an attractive treatment option for this syndrome. Sixteen patients with POEMS syndrome have undergone PBSCT at Mayo. Of these patients, 15 had a severe rapidly progressive sensorimotor PN (9 were wheelchair dependent) and 14 were male. Median age was 51 years (range, 19-62 years). The median number of prior therapies was 3 (range, 0-7). From first symptoms and from diagnosis of POEMS the times to transplantation were 42 months and 5 months (ranges, 8-185 months and 2-149 months), respectively. There were 15 patients who had significantly abnormal pretransplant pulmonary function tests. There was one transplant-related death. During the peritransplant period, 5 patients required intubation for respiratory compromise, including one who required intubation during his stem cell mobilization period. Another patient required noninvasive biphasic positive airway pressure throughout his course. Of the 14 evaluable patients, all have had neurologic improvement or stabilization. Other features have improved substantially. PBSCT for POEMS syndrome is effective therapy but may also be associated with significant morbidity. (Blood. 2004;104:3400-3407)

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.