Systemic amyloidosis from A (AA) to T (ATTR): a review

Systemic amyloidosis is a rare protein misfolding and deposition disorder leading to progressive organ failure. There are over 15 types of systemic amyloidosis, each caused by a different precursor protein which promotes amyloid formation and tissue deposition. Amyloidosis can be acquired or hereditary and can affect various organs, including the heart, kidneys, liver, nerves, gastrointestinal tract, lungs, muscles, skin and soft tissues. Symptoms are usually insidious and nonspecific resulting in diagnostic delay. The field of amyloidosis has seen significant improvements over the past decade in diagnostic accuracy, prognosis prediction and management. The advent of mass spectrometry-based shotgun proteomics has revolutionized amyloid typing and has led to the discovery of new amyloid types. Accurate typing of the precursor protein is of paramount importance as the type dictates a specific management approach. In this article, we review each type of systemic amyloidosis to provide the practitioner with practical tools to improve diagnosis and management of these rare disorders.

Elevated pre-transplant C-reactive protein identifies a high-risk subgroup in multiple myeloma patients undergoing delayed autologous stem cell transplantation

The significance of elevated C-reactive protein (CRP) prior to autologous stem cell transplantation (ASCT) in multiple myeloma (MM) has not been studied. We analyzed 1111 MM patients who underwent ASCT at Mayo Clinic from 2007 to 2015. A total of 840 patients (76%) received early ASCT (⩽12 months from diagnosis) and 271 patients (24%) received delayed ASCT (>12 months from diagnosis). Elevated CRP (> upper normal limit (8 mg/L)) was seen in 14% and 22% of patients undergoing early and delayed ASCT, respectively (P=0.003). There was no correlation of CRP with pre-transplant response, bone marrow plasma cell percentage or labeling index. Patients with an elevated CRP had a higher likelihood of having circulating plasma cells prior to ASCT (33 vs 19%; P<0.001). In the early ASCT cohort, the median overall survival (OS) in patients with normal and elevated CRP was not reached and 91 months respectively (P=0.011). In the delayed ASCT cohort, the median OS in respective groups were 73 and 30 months respectively (P<0.001), with elevated CRP being an independent prognostic marker on multivariate analysis (hazard ratio 2.0; 95% confidence interval, 1.0-3.8; P=0.045). Elevated pre-transplant CRP identifies a high-risk population especially in patients undergoing delayed ASCT and should be incorporated in the pre-transplant evaluation.

Pomalidomide-dexamethasone in refractory multiple myeloma: long-term follow-up of a multi-cohort phase II clinical trial

Despite therapeutic advances, multiple myeloma remains incurable, with limited options for patients with refractory disease. We conducted a large, multi-cohort clinical trial testing various doses and treatment schedules of pomalidomide and dexamethasone (Pom/dex) in patients with refractory multiple myeloma. Overall, 345 patients were enrolled to six cohorts based on number and type of prior lines of therapy, pomalidomide dose and schedule. Median prior lines of therapy were three with near universal prior exposure to proteasome inhibitors and/or immunomodulatory drugs. A confirmed response rate of 35% was noted for all cohorts (range 23-65%) with higher responses in cohorts with fewer prior lines of therapy. Median time to confirmed response was ⩽2 months and the longest progression-free survival and overall survival seen in any cohort were 13.1 and 47.9 months, respectively. Observed adverse reactions were as expected, with myelosuppression and fatigue being the most common hematologic and non-hematologic adverse events (AEs), respectively. Longer durations of treatment and response, higher response rates and fewer AEs were noted with the 2 mg pomalidomide dose. This is the longest follow-up data for Pom/dex in refractory multiple myeloma and will help shape the real-world utilization of this regimen.

Outcomes of maintenance therapy with lenalidomide or bortezomib in multiple myeloma in the setting of early autologous stem cell transplantation

Post-transplant maintenance is widely used in multiple myeloma (MM); however, there is a lack of data on real-world outcomes. We have analyzed 577 patients with newly diagnosed MM undergoing early auto-transplantation between 2010 and 2015. A total of 341, 132 and 104 patients received no, lenalidomide (Len) or bortezomib (Bort) maintenance, respectively. Patients receiving Len or Bort maintenance had a higher incidence of high-risk cytogenetics by fluorescence in situ hybridization (31% (Len) vs 58% (Bort) vs 8% (No); P<0.001). Len maintenance led to a superior progression-free survival (PFS) compared with no maintenance (median, 37 vs 28 months, respectively; P=0.002; adjusted hazard ratio 0.48 (95% CI, 0.35-0.66)), including in subgroups with ISS stage III disease (median, 40 vs 24 months; P=0.008) and high-risk cytogenetics (median, 27 vs 16 months; P=0.032). Bort maintenance did not confer PFS benefit for the entire cohort, but improved PFS in the high-risk cytogenetic subgroup (median, 28 vs 16 months; P=0.035). Discontinuation due to toxicity was seen in 17 and 7% of patients receiving Len or Bort maintenance, respectively. Our results indicate that post-transplant maintenance with Len or Bort is well tolerated in clinical practice and improves PFS in high-risk subgroups of MM patients.

Prevalence and predictors of thyroid functional abnormalities in newly diagnosed AL amyloidosis

BACKGROUND

Data on the effect of systemic immunoglobulin light chain amyloidosis (AL amyloidosis) on thyroid function are limited.

OBJECTIVE

To assess the prevalence of hypothyroidism in AL amyloidosis patients and determine its predictors.

METHODS

1142 newly diagnosed AL amyloidosis patients were grouped based on the thyroid-stimulating hormone (TSH) measurement at diagnosis: hypothyroid group (TSH above upper normal reference; >5 mIU L^-1 ; n = 217, 19% of study participants) and euthyroid group (n = 925, 81%). Predictors for hypothyroidism were assessed in a binary multivariate model. Survival between groups was compared using the log-rank test and a multivariate analysis.

RESULTS

Patients with hypothyroidism were older, more likely to present with renal and hepatic involvement and had a higher light chain burden compared to patients in the euthyroid group. Higher proteinuria in patients with renal involvement and lower albumin in patients with hepatic involvement were associated with hypothyroidism. In a binary logistic regression model, age ≥65 years, female sex, renal involvement, hepatic involvement, kappa light chain restriction and amiodarone use were independently associated with hypothyroidism. Ninety-three per cent of patients in the hypothyroid group with free thyroxine measurement had normal values, consistent with subclinical hypothyroidism. Patients in the hypothyroid group had a shorter survival compared to patients in the euthyroid group (4-year survival 36% vs 43%; P = 0.008), a difference that was maintained in a multivariate analysis.

CONCLUSION

A significant proportion of patients with AL amyloidosis present with hypothyroidism, predominantly subclinical, which carries a survival disadvantage. Routine assessment of TSH in these patients is warranted.

Risk stratification in myeloma by detection of circulating plasma cells prior to autologous stem cell transplantation in the novel agent era

The impact of circulating plasma cells (CPCs) prior to autologous stem cell transplantation (ASCT) for multiple myeloma has not been defined in the novel agent era. We evaluated the impact of pre-transplant CPCs, detected by six-color flow cytometry in patients undergoing early ASCT on post-transplant response, progression-free survival (PFS) and overall survival (OS). CPCs were detected in 162 out of 840 (19.3%) patients, with the median number of CPCs being 58 per 150 000 events. Ninety-nine percent of patients had received proteasome inhibitor and/or immunomodulator-based induction. The incidence of post-transplant stringent complete response (sCR) in the subgroups with and without CPCs was 15% and 38%, respectively, (P<0.001). The median PFS in the subgroups with and without CPCs was 15.1 (95% confidence interval (CI), 12.5-17.8) and 29.6 months (95% CI, 26.2-32.8), respectively, and the median OS was 41.0 months (95% CI, 32.6-58.2) and not reached (NR) (95% CI, 99.1-NR), respectively, (P<0.001 for both). On multivariate analysis for OS, factors independently predictive of mortality were the presence of CPCs (hazard ratio (HR) 2.5; 95% CI, 1.8-3.6; P<0.001) and sCR post transplant (HR 0.4; 95% CI, 0.2-0.6; P<0.001). Presence of CPCs prior to transplant has a high prognostic impact and should be prospectively validated in clinical trials.

The impact of induction regimen on transplant outcome in newly diagnosed multiple myeloma in the era of novel agents

We compared overall survival (OS) of 1017 patients with newly diagnosed multiple myeloma (MM) who were treated with different novel agent-based induction regimens and who underwent early autologous stem cell transplant (ASCT). Subgroups were defined by type of induction therapy: cyclophosphamide-bortezomib-dexamethasone (CyBorD; n=193), bortezomib-dexamethasone (Vd; n=64), lenalidomide-dexamethasone (Rd; n=251), bortezomib-lenalidomide-dexamethasone (VRd; n=126), thalidomide-dexamethasone (Td; n=155) and vincristine-doxorubicin-dexamethasone or dexamethasone alone (VAD/Dex; n=228). The median follow-up of the surviving patients was 66.7 months. The 5-year OS rates with CyBorD, Vd, Rd, VRd, Td and VAD/Dex were 79.2%, 72.3%, 79.2%, 79.0%, 57.4% and 63.4%, respectively (log-rank, P<0.001). In a multivariate analysis, after controlling for important patient and disease variables, VRd had a superior OS compared with CyBorD (hazard ratio (HR), 0.32; 95% confidence interval (CI), 0.10-0.88; P=0.03) and Vd (HR, 0.16; 95% CI, 0.04-0.52; P=0.002). In conclusion, our study demonstrates that among patients completing induction therapy and continuing to early transplant, VRd induction leads to improved OS compared with CyBorD and Vd regimens.

Quantification of circulating clonal plasma cells via multiparametric flow cytometry identifies patients with smoldering multiple myeloma at high risk of progression

The presence of high numbers of circulating clonal plasma cells (cPCs) in patients with smoldering multiple myeloma (SMM), detected by a slide-based immunofluorescence assay, has been associated with a shorter time to progression (TTP) to MM. The significance of quantifying cPCs via multiparameter flow cytometry, a much more readily available diagnostic modality, in patients with SMM has not been evaluated. This study evaluated 100 patients with a known or new diagnosis of SMM who were seen at the Mayo Clinic, Rochester from January 2008 until December 2013. Patients with ⩾150 cPCs (N=9) were considered to have high number of cPCs based on the 97% specificity and 78% PPV of progression to MM within 2 years of cPC assessment. The median TTP of patients with ⩾150 cPCs was 9 months compared with not reached for patients with <150 cPCs (P<0.001). Thus, quantification of cPCs via multiparametric flow cytometry identifies patients with SMM at very high risk of progression to MM within 2 years and warrants confirmation in larger studies. In the future, this may allow reclassification of such patients as having MM requiring therapy prior to them enduring end-organ damage.

Early relapse following initial therapy for multiple myeloma predicts poor outcomes in the era of novel agents

Outcomes for patients with multiple myeloma (MM) have improved in recent years owing to use of novel agents and high-dose therapy followed by autologous stem cell transplant (ASCT). We analyzed the outcomes of 511 consecutive patients treated with novel therapies at our institution between 2006 and 2014 to determine the impact of relapse within 12 months of initiating treatment. A total of 82 patients (16.0%) experienced early relapse, with median time to relapse of 8.0 months (95% confidence interval (CI); 6.3, 8.9). Median overall survival (OS) was significantly worse for this group at 21.0 months (95% CI; 16.3, 27.2) vs not reached (NR) (95% CI; 96.3, NR) for those with late relapse (P<0.001). Survival outcomes remained poor among early relapse patients irrespective of depth of response to initial therapy. In multivariate analysis, low albumin and high-risk cytogenetics predicted early relapse. Outcomes of early relapse from early ASCT were also considered; median OS from ASCT for those relapsing within 12 months was 23.1 months (95% CI; 15.7, 32.4) vs 122.2 months (95% CI; 111.5, 122.2) for the remaining patients (P<0.001). Early relapse remains a marker of poor prognosis in the current era, and such patients should be targeted for clinical trials.

Improvement in renal function and its impact on survival in patients with newly diagnosed multiple myeloma

Renal impairment (RI) is seen in over a quarter of patients with newly diagnosed multiple myeloma (NDMM). It is not clear if reversal of RI improves the outcome to that expected for NDMM patients without RI. We evaluated 1135 consecutive patients with NDMM seen at the Mayo Clinic between January 2003 and December 2012. RI was defined as having a creatinine clearance (CrCl) <40ml/min. The median overall survival (OS) for patients with RI at diagnosis receiving and not receiving novel agent induction therapy was not reached vs 46 months (P<0.001). The median OS for patients with CrCl ⩾40 ml/min at diagnosis, CrCl <40 ml/min at diagnosis but improved to ⩾40 ml/min and CrCl <40 ml/min at diagnosis and remained <40 ml/min, were 112, 56 and 33 months, respectively (P<0.001). The complete renal response rate for patients with RI at diagnosis receiving novel agent induction therapy compared to the rest was 40 vs 16% (P<0.001). In conclusion, patients with reversal of RI have improved outcomes, but it remains inferior to patients with normal renal function at diagnosis. These results have implications for identifying early treatment strategies for patients at risk of developing renal insufficiency.

Continued improvement in survival in multiple myeloma: changes in early mortality and outcomes in older patients

Therapy for multiple myeloma (MM) has markedly changed in the past decade with the introduction of new drugs, but it is not clear whether the improvements have been sustained. We studied 1038 patients diagnosed between 2001 and 2010, grouping patients into two 5-year periods by diagnosis, 2001-2005 and 2006-2010. The median estimated follow-up for the cohort was 5.9 years with 47% alive at the last follow-up. The median overall survival (OS) for the entire cohort was 5.2 years: 4.6 years for patients in the 2001-2005 group compared with 6.1 years for the 2006-2010 cohort (P=0.002). The improvement was primarily seen among patients over 65 years, the 6-year OS improving from 31 to 56%, P<0.001. Only 10% of patients died during the first year in the latter group, compared with 16% in the earlier cohort (P<0.01), suggesting improvement in early mortality. The improved outcomes were linked closely to the use of one or more new agents in initial therapy. The current results confirm continued survival improvement in MM and highlight the impact of initial therapy with novel agents. Most importantly, we demonstrate that the improved survival is benefitting older patients and that early mortality in this disease has reduced considerably.

Quantification of clonal circulating plasma cells in newly diagnosed multiple myeloma: implications for redefining high-risk myeloma

The presence of clonal circulating plasma cells (cPCs) is a marker of high-risk disease in all stages of monoclonal gammopathies. However, the prognostic utility of quantitating cPCs using multiparametric flow cytometry in multiple myeloma (MM) patients with current treatments is unknown. There were 157 consecutive patients with newly diagnosed MM seen at the Mayo Clinic, Rochester from 2009 to 2011 that had their peripheral blood evaluated for cPCs by multiparameter flow cytometry. Survival analysis was performed by the Kaplan-Meier method and differences assessed using the log-rank test. Using a receiver operating characteristics (ROC) analysis, ⩾400 cPCs were considered as the optimal cutoff for defining high-risk disease. The presence of ⩾400 cPCs was associated with higher plasma cell (PC) proliferation and adverse cytogenetics. The median time-to-next-treatment and overall survival (OS) in patients with ⩾400 cPCs (N=37, 24%) was 14 months and 32 months compared with 26 months and not reached for the rest (P<0.001). In a multivariable model, the presence of ⩾400 cPCs and older age adversely affected OS. Flow cytometry to quantify cPCs is a valuable test for risk stratifying newly diagnosed MM patients in the era of novel agents. Future studies are needed to determine its role in developing a risk-adapted treatment approach.

Long-term outcome with lenalidomide and dexamethasone therapy for newly diagnosed multiple myeloma

The combination of lenalidomide and dexamethasone (Len-Dex) is a commonly used initial therapy for newly diagnosed multiple myeloma (MM). Although the initial response rates and toxicity are well known, long-term outcome is not well described. We studied 286 consecutive patients with newly diagnosed MM initially treated with Len-Dex. The median (range) age at diagnosis was 63 (28-92) years, 166 (58%) patients ≤ 65 years and 175 (61%) male. The median estimated duration on Len-Dex was 5.3 months with overall response (≥ partial response) of 72%, including 26% with very good partial response or better. The median overall survival (OS) from the diagnosis was not reached (NR) and the estimated 5-year survival was 71%. The median time to first disease progression, irrespective of transplant status, was 30.2 months. Overall, 143 (50%) patients underwent stem cell transplant. The median OS was NR for patients ≤ 70 years and 5.8 years for the older patients (P=0.01). The 5-year OS estimate for patients in International Staging System stage 1, 2 and 3 were 82, 65, and 44% respectively. There were 21 new second malignancies after MM diagnosis (6.6%). The median survival exceeding 7 years reflects the efficacy of novel agents. The risk of second malignancies doesn't appear to be excessive in this population.

SCT without growth factor in multiple myeloma: engraftment kinetics, bacteremia and hospitalization

SCT is important in the management of multiple myeloma. In the United States, the standard of care is administration of growth factors to accelerate neutrophil recovery after SCT. The need for growth factors after transplant has not been investigated recently. We analyzed a cohort of 166 patients at our institution who underwent autologous transplant for multiple myeloma without receiving growth factors after transplant and compared them with 498 patients who received standard filgrastim beginning on posttransplant day 5. A neutrophil count of 500/μL was achieved in a median of 12.5 days in patients receiving growth factor, compared with 13.5 days in those not receiving growth factor (P<0.001). Platelet engraftment was identical (median, 14.5 days; P=0.12) in both groups, despite a lower median number of CD34+ cells infused in patients who did not receive growth factors. Incidence of nonstaphylococcal bacteremia was identical in both groups. The median hospital stay was 3.5 days shorter in the group not receiving growth factor. It is feasible and reasonable to perform autologous SCT for multiple myeloma without administering growth factors.

Low risk of symptomatic venous thromboembolic events during growth factor administration for PBSC mobilization

The use of erythropoietic agents has been associated with an increased risk of venous thromboembolic events (VTEs), especially in patients with underlying malignancies. However, it is not known whether there is an increased risk of VTE associated with granulocyte growth factors. We reviewed 621 patients undergoing PBSC mobilization using granulocyte growth factors, alone or in combination with CY. Patients with a diagnosis of AL amyloidosis (AL: 114; 18%), multiple myeloma (MM: 278; 44%) Hodgkin lymphoma (HL: 20; 3%) or non-Hodgkin lymphoma (NHL: 209; 33%) were included. Symptomatic VTE occurred in six (0.97%) patients: two AL, two MM and two NHL. Of the six patients, two had pulmonary embolism, one developed deep vein thrombosis and three developed symptomatic catheter related thrombosis. Two patients with AL had heparin-induced thrombocytopenia and thrombosis. We found a low incidence of VTE among patients undergoing PBSC mobilization.

Stem cell transplantation in patients with autonomic neuropathy due to primary (AL) amyloidosis

OBJECTIVES

Patients with AL amyloidosis can benefit from high-dose chemotherapy and autologous stem cell transplantation (ASCT). Transplantation can be challenging due to fluid shifts, sepsis, and cardiac dysrhythmias. Amyloidosis may present with autonomic neuropathy (AN) that renders peritransplant care problematic. The purpose of this study was to determine the outcome of patients with AN during and after ASCT.

METHODS

We performed a case-control study of patients with AL amyloidosis with associated AN and compared them to a large matched cohort without AN who also underwent ASCT.

RESULTS

We identified 13 patients with AN who underwent ASCT and a matched control group of 95 patients without AN. Patients with AN had more organs involved (median 2.5 vs 1, p < 0.001) and the conditioning dose of melphalan was often reduced by 30% compared to controls without AN (p = 0.0015). Median duration of hospitalization was similar for both cohorts, as were engraftment kinetics. Atrial fibrillation occurred in all patients with AN but in only 1 control patient (p < 0.0001). Median overall survival (OS) for patients with AN was 29 months but >60 months for controls (p < 0.0001). On univariate analysis, cardiac involvement (p = 0.0132), AN (p = 0.0011), glomerular filtration rate (p = 0.038), number of organs involved (p = 0.0064), and NT-pro-BNP (p = 0.039) all had an impact on OS. On multivariate analysis, AN retained an independent adverse impact on OS.

CONCLUSIONS

Patients with autonomic neuropathy secondary to AL amyloidosis can undergo autologous stem cell transplantation with relative safety. Autonomic neuropathy is an independent, adverse determinant of survival in these patients.

Natural history of multiple myeloma (MM) relapsing after autologous stem cell transplantation (ASCT)

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Background: The outcome of patients with MM relapsing after ASCT used early in the disease course or after failure of initial therapy, is not well defined. We undertook this study to understand treatment approaches for patients relapsing after single ASCT. Methods: Patients relapsing after single ASCT were identified from a prospectively maintained database and relevant clinical data were extracted from medical records. Relapse and treatment responses were according to IMWG Uniform Response Criteria. Patients relapsing between Jan 2000 and 2008 were included in order to capture a recent cohort contemporaneous to availability of novel drugs. Results: We studied 487 patients who had relapsed following a single ASCT, of whom 351 (72%) had an early SCT (≤ 12 mos from diagnosis). The median estimated follow up for all patients was 27 mos, 50 mos and 69 mos from relapse, SCT and diagnosis respectively. The median overall survival (OS) from the time of relapse was 30 mos for the early SCT group and 21 months for the late SCT group. The median time to relapse following transplant was 15 mos (3–119) among early SCT group and 12 mos (3–76) among the late SCT group. Longer time to relapse as well as longer time from relapse to initiation of therapy were independent predictors of better outcome. Among the early group, nearly a third of the patients achieved a PR or better to first salvage therapy (Table), with another third achieving stable disease and 25% of patients did not have response data. The median progression free survival for the first salvage regimen was 8 mos; 18 mos for those with PR or better and 5 mos for those with SD as the best response. Data on the regimen 2, 3, 4, 5, and 6 were available for 211, 133, 84, 53 and 28 patients respectively. As expected, the response rates and the response duration decreased with increasing number of relapses. Conclusions: Patients relapsing after ASCT can obtain prolonged response duration with the currently available treatments. Those with a durable response to transplant and those not requiring initiation of therapy for long periods after disease relapse have favorable disease biology and have prolonged survival after relapse. The natural history of the disease provides a valuable benchmark for evaluation of newer treatment approaches.

No significant financial relationships to disclose.

Prognostic value of stringent complete response (sCR) post-autologous stem cell transplant (SCT) in multiple myeloma (MM)

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Background: The measurement of serum immunoglobulin free light chains (FLC) has diagnostic and prognostic utility in MM. Normalization of the FLC ratio may define a deeper complete response after therapy than by standard criteria of CR. A sCR requires normalization of the FLC ratio and absence of clonal plasma cells in the bone marrow (BM) in addition to the standard criteria for CR. The objective of our study was to evaluate the impact of specific types of CR [sCR, CR or near CR (nCR/ immunofixation positive CR)] post-SCT on time to progression (TTP) and overall survival (OS). Methods: 468 MM patients who had achieved at least a partial response post-SCT were studied. The results of serum and urine protein studies, serum FLC assay, and BM evaluation, including measurement of marrow plasma cell clonality by immunohistochemistry obtained ≥60 days after SCT were used to determine the best response. TTP was defined as the time from SCT to progression, with non-myeloma related deaths censored. Results: 179 patients achieved varying degrees of CR as their best response. 39, 35 and 105 patients achieved nCR, CR and sCR, respectively. The median estimated follow-up for the entire cohort was 52 months from the diagnosis and 41 months from SCT. The median TTP was 15, 29 and 35 months for patients achieving nCR, CR and sCR, respectively (P<0.0001). The median OS for patients achieving nCR was 53 months from the diagnosis, but not reached for those with a CR or sCR (P=0.0009). The 5-year OS was 80% and 79% for patients with CR and sCR, respectively (P=NS). Similarly, OS from SCT was significantly shorter in patients achieving nCR (42 months vs. not reached for patients in CR and sCR; P<0.001). Conclusions: Achievement of a sCR represents a deeper response state compared to conventional CR, translating to a longer response duration post SCT, validating its inclusion in the modified uniform response criteria. While we did not see a significant improvement in OS with sCR compared to CR in this group, this question needs to be addressed in a larger study. The step wise improvement in the response duration across nCR, CR and sCR highlights the contribution of immunofixation studies, marrow assessment of clonality and FLC estimates.

[Table: see text]

Comparison of high-dose CY and growth factor with growth factor alone for mobilization of stem cells for transplantation in patients with multiple myeloma

We retrospectively analyzed outcomes of 716 patients with multiple myeloma who were mobilized using CY and growth factor (n=370) or growth factor alone (n=346) before SCT. Patients receiving CY had higher stem cell yields than the growth factor only group (median number of apheresis sessions needed to achieve stem cell collection goals, two vs four sessions, respectively (P=0.001)). However, patients treated with CY required more time for engraftment of platelets and neutrophils (P<0.001 for both). For patients receiving CY, 75% achieved engraftment (defined as a platelet count of 50 x 10(9)/l) by day 39, whereas 75% of patients not receiving CY achieved engraftment by day 18. Similar results were observed for neutrophil engraftment. These differences did not affect the duration of hospitalization, but patients treated with CY had a higher incidence of post transplant nonstaphylococcal bacteremia. For CY-mobilized patients, considerably faster platelet engraftment (5 fewer days) resulted if stem cell reinfusion occurred more than 30 days after the first apheresis session. Our data suggested that CY damaged the microenvironment and slowed engraftment. By lengthening the period between the completion of apheresis and stem cell reinfusion, the microenvironment may recover and result in faster engraftment.

Impact of lenalidomide therapy on stem cell mobilization and engraftment post-peripheral blood stem cell transplantation in patients with newly diagnosed myeloma

While initial therapies have become highly effective with introduction of lenalidomide and bortezomib and patients may opt for delayed stem cell transplantation, it is important to collect stem cells for future transplant. Given its increasing use as initial therapy, we examined if lenalidomide had any impact on the ability to collect peripheral blood stem cells (PBSC). We studied the entire cohort of patients with myeloma undergoing PBSC mobilization at our institution during a 5-year period, comparing the results between patients receiving different initial therapies. Among those mobilized with granulocyte-colony stimulating factor (G-CSF) alone, there was a significant decrease in total CD34(+) cells collected (P<0.001), average daily collection (P<0.001), day 1 collection (P<0.001) and increased number of aphereses (P=0.004) in patients treated with lenalidomide compared to those receiving dexamethasone, thalidomide-dexamethasone or VAD. A similar trend was seen in those mobilized with chemotherapy and G-CSF. A trend was seen towards decreased PBSC yield with increasing duration of lenalidomide therapy as well as increasing age (P=0.002). There was no effect on quality of PBSC collected based on similar engraftment across all groups. We recommend collection of PBSC within 6 months of initiation of therapy with lenalidomide containing regimens to minimize the risk of mobilization failures.

Autologous hematopoietic stem cell transplantation for older patients with relapsed non-Hodgkin's lymphoma

To evaluate autologous stem cell transplant (ASCT) in older patients with intermediate grade non-Hodgkin's lymphoma (NHL), the Mayo Clinic Rochester BMT database was reviewed for all patients 60 years of age and older who received ASCT for NHL between September 1995 and February 2003. Factors evaluated included treatment-related mortality (TRM), event-free survival (EFS) and overall survival (OS). Ninety-three patients were identified, including twenty-four (26%) over the age of 70 years. Treatment-related mortality (5.4%) was not significantly different when compared to a younger cohort (2.2%). At a median follow-up of 14 months (0.6-87.6 months), the estimated median survival is 25 months (95% confidence interval (CI) 12-38) in the older group compared to 56 months (95% CI 37-75) (P=0.037) in the younger group. The estimated 4-year EFS was 38% for the older group compared to 42% in the younger cohort (P=0.1). By multivariate analysis, the only factor found to influence survival in the older group was age-adjusted International Prognostic Index at relapse, 0-1 better than 2-3 (P=0.03). Autologous stem-cell transplant can be safely performed in patients 60 years or older with chemotherapy sensitive relapsed or first partial remission NHL. The outcome may not be different from that of younger patients in terms of TRM and EFS.