Median Plasma Cell Percentage Research Articles

#6652 ACUTE KIDNEY INJURY IN PATIENTS WITH MULTIPLE MYELOMA SUBMITTED TO AUTOLOGOUS HEMATOPOIETIC CELL TRANSPLANT: A COHORT ANALYSIS

Abstract Background and Aims The incidence of most haematological neoplasms has been increasing and with them hematopoietic cell transplantation (HCT) as it provides better survival rates to several of these malignancies. There is a wide range of acute kidney injury (AKI) reported incidence in HCT patients, mostly due to the heterogeneity of AKI definitions and study populations that include different underlying illnesses. We aimed to evaluate incidence, severity and risk factors of AKI by KDIGO classification considering creatinine and urinary output (UO) criteria in patients with multiple myeloma (MM) submitted to autologous HCT. Method We conducted a retrospective cohort study including patients with MM submitted to autologous HCT admitted in a tertiary hospital between Jan./2005-Dec./2015 with a 3 year follow-up period. To evaluate AKI cumulative incidence, risk factors and impact on relapse, survival analysis methods considering death as competing were used. Multivariate stepwise analysis using logistic regression was used to evaluate risk factors associated with AKI. Results 143 patients were included [median age was 50.5 (59.2-63.6) years, 61.5% male and 90.9% Caucasian]. 37.1% had hypertension, 12.6% diabetes mellitus and 10.5% chronic kidney disease (CKD) [median overall baseline eGFR 100.4 (89.5-110.8) mL/min/1.73 m2]. Median percentage of plasma cells on bone marrow aspirate was 30 (17-67) %, serum M-protein 3.3 (2.2-6.6) g/dL and serum titre of the affected light chain 3560 (890-7800) mg/dL. 49 patients had cytogenetic abnormalities. 49% of patients had R-ISS stage I at diagnosis. Median number of previous lines of therapy was 1 (1-2) and the median number of cycles 4 (3-4). 34.5% were previously submitted to radiotherapy. At admission, mean haemoglobin was 11.7 (10.8-12.4) g/dL, neutrophils 3375 (2330-4765) /mm3, serum urea 33 (28-44) mg/dL, uric acid 5 (4.1-6) mg/dL, phosphate 3.4 (3-2.9) mg/dL, LDH 333 (297-390) U/L, albumin 3.9 (3.7-4.2) mg/dL and alanine transaminase 18 (14-27) U/L. Fever (77.6%), exposure to nephrotoxins (74.1%), low grade mucositis (55.9%) and sepsis (26.6%) were common during hospital admission. Cumulative incidence of AKI at 100 days was 49.7% (71 patients) with median time to event of 8 (5-13) days. 85.9% of patients had stage 1 AKI at diagnosis, although 16.4% of these (10 patients) degraded to worse stages. On univariable analysis, the predictor variables with impact on AKI were higher age (p=0.057), higher body mass index (BMI) (p=0.048), HCT-comorbidity index ≥2 (p=0.005), lower baseline eGFR (p<0.001), previous CKD (p=0.001), presence of amyloidosis (p=0.078), higher R-ISS (p=0.002), presence of cytogenetic abnormalities (p=0.055), development of sepsis (p=0.016), fever (p=0.044) and higher grade mucositis (p<0.001), exposure to nephrotoxins (p=0.007), higher neutrophils count (p=0.021), serum urea (p<0.001) and LDH (p=0.002) and lower phosphate (p=0.049), and alanine transaminase (p=0.077). Multivariable analysis showed an independent association of AKI with BMI [HR 1.08 (1.03-1.14), p=0.004], CKD [HR 3.00 (1.55-5.78), p=0.001], amyloidosis [HR 2.73 (1.40-5.33), p=0.003], high grade mucositis [HR 2.35 (1.37-4.02), p=0.002], exposure to nephrotoxins [HR 2.20 (1.08-4.47), p=0.029], leukocyte count [HR 1.01 (1.01-1.01), p<0.001] and serum phosphate [HR 0.57 (0.39-0.84), p=0.004] maintained an independent association with AKI. Conclusion Our results show that AKI occurs in almost half of the patients with MM submitted to HCT and reinforce the need for prevention, monitoring and early approach to AKI in these patients particularly in those with higher BMI, CKD, secondary amyloidosis, higher leukocyte count and lower serum phosphate at admission, as well as in those that develop mucositis and are exposed to nephrotoxins. We also believe considering both SCr and UO KDIGO criteria for AKI may have increased the reliability of our data, this being the first study to include both criteria in this population of patients.

Treatment of Primary Plasma Cell Leukemia with Carfilzomib and Lenalidomide-Based Therapy: Results of the Final Analysis of the Prospective Phase 2 EMN12/HOVON-129 Study for Patients Aged 18-65 Years

Introduction. Primary plasma cell leukemia (pPCL) is a rare and aggressive plasma cell disorder with a very poor prognosis. The median PFS for transplant-eligible patients (pts) is approximately 9 months. The aim of the EMN12/ HOVON-129 study was to improve the outcome of pPCL by incorporating carfilzomib and lenalidomide in induction, consolidation, and maintenance. The trial enrolled 61 pts aged 18 years and older, with different treatment for those aged 18-65 (n=36) and ≥66 years (n=25). Here we report the results of the final analysis for pts aged 18-65 years. Methods. The EMN12/HOVON-129 study is a prospective, non-randomized, phase 2, multicenter study, for previously untreated pPCL pts. Inclusion criteria were newly diagnosed pPCL (defined as >2x109/L circulating monoclonal plasma cells or plasmacytosis >20% of the differential white cell count) and WHO performance status 0-3. Main exclusion criteria were severe cardiac or pulmonary dysfunction; and creatinine clearance of <15 ml/min. There were no restrictions based on blood counts. Pts aged 18-65 years were treated with induction therapy with four 28-day cycles of carfilzomib-lenalidomide-dexamethasone (KRd; carfilzomib 20/36 mg/m2 on days 1,2,8,9,15,16; lenalidomide 25 mg days 1-21; dexamethasone 20 mg on days 1,2,8,9,15,16,22,23). KRd induction was followed by tandem autologous stem cell transplantation (ASCT), 4 cycles of KRd consolidation, and then maintenance with carfilzomib (27 mg/m2 on days 1,2,15,16) and lenalidomide (10 mg on days 1-21/28 days) until progression. Pts who were eligible for allo-SCT, could also receive one ASCT, followed by 2 KRd consolidation cycles, reduced-intensity conditioning allo-SCT, and carfilzomib/lenalidomide maintenance. The primary endpoint was PFS, and secondary endpoints were response rate, OS, and toxicity. Results. From October 2015 till August 2021, we enrolled 36 pts with pPCL aged ≤65 years. Median age was 60 years; 67% had bone disease; and WHO performance status was ≥2 in 33% of pts. Pts had a high tumor burden with a median plasma cell percentage in BM of 80%. The median peripheral blood plasma cell count was 4.1x109/L (range 1.6-60.0); median platelet count was 111x109/L (range 20-517); and median eGFR was 54.0 ml/min (range 15.0-123). Pts had high-risk disease as evidenced by elevated LDH in 58%; and high frequency of high-risk genetic lesions (del(17p) in 47%, t(4;14) in 9%, t(14;16) in 19%, gain/ampl(1q) in 61%). Two or more high-risk cytogenetic abnormalities were present in 38%. The frequency of t(11;14) was 26%. In addition, 17% of pts had extramedullary plasmacytomas. ISS stage 3 was present in 64%, and revised ISS stage 3 in 50%. Response to induction was ≥PR in 72%, ≥VGPR in 64%, and ≥CR in 14%. Twenty-four pts (67%) received high-dose melphalan (HDM)/ASCT; 12 pts (33%) underwent a second course of HDM/ASCT; and 5 (14%) received allo-SCT after first HDM/ASCT. Eighteen pts (50%) received maintenance treatment. Best response on protocol was ≥PR in 83%, ≥VGPR in 81% and ≥CR in 50%; 10 (28%) pts achieved MRD-negative (10-5) CR. With a median follow-up of 40.8 months (range 8-2-74.5), the median PFS was 15.5 months (95% CI 9.4-38.4), which was sufficient to reject our null hypothesis (median PFS=9 months). With 19 pts having died (14 due to disease progression, 4 due to infections, and 1 due to cardiac disorder), median OS was 28.4 months (95% CI 15.1-not reached). In exploratory analyses, the presence of elevated LDH, t(14;16), and del(17p) were associated with both inferior PFS and OS. For patients who underwent first HDM/ASCT, median PFS and OS were 32.9 and 34.1 months from date of ASCT, resp. Adverse events mainly occurred during the first cycle of KRd, and decreased thereafter. Overall, grade ≥3 adverse events were observed in 67% of pts, including infections (25%) and cardiovascular disorders (14%). One patient developed a second primary malignancy (MDS). As of July 24 2022, 25 pts (69%) pts discontinued protocol treatment, mainly because of progression, but none because of treatment-related toxicity. Conclusions. KRd induction provides efficient and rapid disease control, which allows two-thirds of pts to undergo a first course of HDM/ASCT. Toxicity occurred mainly during the first cycle of induction, and was manageable with appropriate interventions. However, median PFS and OS remain low in pPCL, compared to MM. This trial was registered at https://trialsearch.who.int as NTR5350 Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Carfilzomib and Lenalidomide for the Treatment of Primary Plasma Cell Leukemia: Final Results of the Prospective Phase 2 EMN12/HOVON-129 Study for Patients Aged ≥66 Years

Introduction. Primary plasma cell leukemia (pPCL) is a rare and aggressive plasma cell disorder with a very poor prognosis, requiring urgent action to prevent early mortality and to control the disease and complications. The EMN12/HOVON-129 study assessed the efficacy of carfilzomib and lenalidomide as part of first-line therapy in pPCL. The trial enrolled patients (pts) aged 18 years and older, with different treatment for those 18-65 and ≥66 years. Here we report the results for pts in the age-group ≥66 years. Methods. The EMN12/HOVON-129 study is a prospective, non-randomized, phase 2, multicenter study for previously untreated pPCL pts. Inclusion criteria were newly diagnosed pPCL (in this study defined as >2x109/L circulating monoclonal plasma cells and/or plasmacytosis >20% of the differential white cell count) and WHO performance status 0-3. Main exclusion criteria were severe cardiac or pulmonary dysfunction and creatinine clearance <15 ml/min. There were no restrictions based on blood counts. Pts ≥66 years received induction therapy with eight 28-day cycles of carfilzomib-lenalidomide-dexamethasone (KRd; carfilzomib 20/36 mg/m2 on days 1,2,8,9,15,16; lenalidomide 25 mg on days 1-21; dexamethasone 20 mg on days 1,2,8,9,15,16,22,23), followed by maintenance with carfilzomib (27 mg/m2 on days 1,2,15,16 for the first twelve cycles; then 56 mg/m2 on days 1,15) and lenalidomide (10 mg on days 1-21/28 days) until progression. The primary endpoint was progression-free survival (PFS); secondary endpoints were response rate, overall survival (OS), and toxicity. Results. From October 2015 to August 2021, we enrolled 61 pts with pPCL: 36 aged ≤65 years and 25 aged ≥66 years. Among the 25 pts aged ≥66 years, median age was 71 years (range 66-84); 68% had bone disease; and WHO performance status was 2 in 24% and 3 in 16% of pts. Median plasma cell percentage in bone marrow biopsy was 80% (10-100). Median peripheral blood plasma cell count was 3.8x109/L (range 2.0-52); median platelet count was 142x109/L (range 13-384); and median GFR was 56 ml/min (range 24-95). Most of pts had high-risk disease features, as proved by elevated LDH in 52% and high frequency of poor-risk genetic lesions (del(17p) in 20%, t(4;14) in 4%, t(14;16) in 4%, and gain/amp(1q) in 48%). In addition, 12% of pts had extramedullary plasmacytomas. ISS stage III was present in 68% and Revised ISS stage III in 40%. At the data cut-off (July 1, 2022), among the 25 pts, 17 (68%) received the planned 8 cycles of induction treatment, achieving ≥partial response (PR) in 80%, ≥very good (VG)PR in 68%, and ≥complete response (CR) in 32% of pts. Sixteen pts (64%) received maintenance treatment. Best response on protocol was ≥PR in 80%, ≥VGPR in 68% and ≥CR in 36%; 3 out of 4 pts in CR who could be evaluated for minimal residual disease (MRD) achieved MRD negativity (10-5) by flow cytometry. With a median follow-up of 24.6 months (range 7.9-59.6), the median PFS was 13.8 months (95% CI 9.2-35.5), which was sufficient to reject our null hypothesis (median PFS=6.5 months). With 16 pts having died (8 due to disease progression, 2 unknown, 1 pneumonia, 1 sepsis, 1 systemic aspergillus infection, 1 small intestinal SPM, 1 disseminated intravascular coagulation, 1 respiratory failure due to COPD exacerbation), median OS was 24.8 months (95% CI 14-not reached [NR]; Figure). Adverse events mainly occurred during the first two cycles of KRd and decreased thereafter. Overall, 36% of pts had grade (G)3 and another 36% G4 adverse events. G3 and G4 hematologic toxicity rates were 8% and 12%, respectively. Infections (20% and 16%) and respiratory events (16% and 4%) were the most common G3 and G4 non-hematologic toxicities. Twenty-two pts (88%) discontinued protocol treatment, mainly because of progression (13 pts, 59%). Conclusions. KRd is a potent treatment strategy to control disease in pPCL pts over 65 years of age, with not negligible, but generally manageable, treatment-related toxicities. Of note, along with a significant improvement of PFS, median OS substantially doubled compared to what has been reported in recent retrospective studies and, particularly, in the only other prospective trial (with the doublet lenalidomide-dexamethasone) so far conducted in transplant ineligible, elderly pts with pPCL (Musto P et al. Leukemia. 2014;28:222-5). This trial was registered at www.trialregister.nl (until June 2022) and https://trialsearch.who.int/ as NTR5350. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Association between BCL2, BCL2 E17, MCL1 and BAX Protein Expression, Bone Marrow Microenvironment Histological Features, Clinical Presentation, Therapeutic Outcome, and the Overall Survival in Newly Diagnosed Multiple Myeloma

Association between BCL2, BCL2 E17, MCL1 and BAX Protein Expression, Bone Marrow Microenvironment Histological Features, Clinical Presentation, Therapeutic Outcome, and the Overall Survival in Newly Diagnosed Multiple Myeloma

Impact of Autologous Hematopoietic Cell Transplant (HCT) Followed By Dendritic Cell/Myeloma Fusion Vaccine with Lenalidomide Maintenance in Increasing Multiple Myeloma (MM) Immunity (BMT CTN 1401)

Impact of Autologous Hematopoietic Cell Transplant (HCT) Followed By Dendritic Cell/Myeloma Fusion Vaccine with Lenalidomide Maintenance in Increasing Multiple Myeloma (MM) Immunity (BMT CTN 1401)

Clinical Significance and Biomarkers to Predict Unsustained Complete Remission in Transplant-Eligible Multiple Myeloma

Clinical Significance and Biomarkers to Predict Unsustained Complete Remission in Transplant-Eligible Multiple Myeloma

Treatment of Primary Plasma Cell Leukemia with Carfilzomib and Lenalidomide-Based Therapy: Results of the First Interim Analysis of the Phase 2 EMN12/HOVON129 Study

Treatment of Primary Plasma Cell Leukemia with Carfilzomib and Lenalidomide-Based Therapy: Results of the First Interim Analysis of the Phase 2 EMN12/HOVON129 Study

Clinical Outcomes and Cytogenetic Features of Primary Plasma Cell Leukemia (pPCL) in the Era of Novel Agent Induction Therapy

Clinical Outcomes and Cytogenetic Features of Primary Plasma Cell Leukemia (pPCL) in the Era of Novel Agent Induction Therapy

Addition of Bortezomib to Melphalan Plus Dexamethasone Provides Rapid Response in AL Amyloidosis

Background and ObjectivesSystemic immunoglobulin light chain (AL) amyloidosis is characterized by the deposition of misfolding proteins produced by monoclonal plasma cells. The process of amyloid deposition produces tissue damage and eventually organ failure leading to death. Although various organs including heart, kidneys, gastrointestinal tract, and liver are involved, cardiac damage mainly affects prognosis. Median survival time of patients with cardiac amyloidosis has reported to be four to six months. The ideal goal of treatment is the elimination of amyloid protein from involved organs, which is not available so far. We instead try to inhibit the growth of the monoclonal plasma cells to reduce the supply of amyloidogenic light chains. For this purpose, a treatment with high dose melphalan supported by autologous stem cell transplantation (ASCT) was introduced and achieved some positive results. However, treatment-related mortality of ASCT is as high as 10% even if using risk-adapted approach to adjust the dose of melphalan. Moreover, indication of ASCT is limited to "fit" patient. For "unfit" patients, melphalan plus dexamethasone (MD) treatment is the standard of care, which shows similar response rate and better survival to ASCT in a randomized study. One of the concerns in MD treatment is a long time to response. According to a report, median time to response in MD treatment is 4.5 months, which is almost same as median survival in patients with cardiac amyloidosis. In this study, we evaluated the feasibility and activity of MD in combination with bortezomib for patients with AL amyloidosis.MethodsPatients with histologically proven, newly diagnosed systemic AL amyloidosis received MDB regimen including oral melphalan (10 mg/m2 of body surface area (BSA) on days 1 to 4), oral dexamethasone (40 mg/day on days 1 to 4), and bortezomib (1.3 mg/m2 of BSA on days 8, 15, 22) for up to 12 courses if no severe adverse events occurred. Hematologic response was assessed at the beginning of each cycle according to new consensus criteria of the International Society of Amyloidosis.ResultsEight patients were retrospectively analyzed in this study, six were men. The median age at diagnosis was 60 years (range, 52 - 69 years). Involvement of one organ was present in two patient, two organs were involved in four, and three or more organs in the remaining two. Seven patients had a lambda monoclonal protein, and the median percentage of plasma cells in the bone marrow was 4.1% (range, 1.0% - 29.8%). No patient has received treatment before MDB regimen. The median number of treatment cycles was four (range, 1 to 12). In seven evaluable patients, the hematologic CR achieved in three patients, VGPR in three, and PR in one. In six cases evaluable by using FLC, the median time to PR (dFLC decrease >50%) was 55 days and median time to VGPR (dFLC <40 mg/L) was 51 days. Involved FLC at baseline and after each cycle of MDB in these cases was shown in figure. Adverse events which required discontinuation include sudden cardiac arrest in one case, deterioration of cardiac function in one case, and fatigue in two cases.ConclusionsAddition of bortezomib once a week for three weeks to standard melphalan and dexamethasone treatment provides rapid hematologic response (median time to PR: 55 days). With caution of deterioration of cardiac function, the MDB regimen may be a useful option for cardiac amyloidosis patients needing the prompt reduction of pathogenic light chain. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

B Type Natriuretic Peptide (BNP) Less Than 200 Pg/Ml Represents Good Candidate For High Dose Melphalan and Predicts Longer Survival In Systemic Light Chain Amyloidosis

BackgroundHigh dose melphalan with autologous stem cell transplantation (ASCT) is a standard treatment for eligible patients with systemic light chain (AL) amyloidosis. Treatment-related mortality (TRM) of ASCT for AL amyloidosis was previously reported being as high as 40%; however, risk-adapted melphalan dosing reduced TRM to about 10% or less in experienced institutes. Several ways to determine the dose of melphalan have been proposed. They were focusing on organ failures especially cardiac dysfunction shown by ejection fraction (EF). EF represents contractile function of the heart; however, in AL amyloidosis, EF is known to be maintained until late stage whereas diastolic function is damaged earlier. We here present the outcomes of AL patients who received ASCT following risk-adapted melphalan with our criteria including B type natriuretic peptide (BNP) which is a practical marker for diastolic function of the heart and less affected by the renal function than NT-proBNP. Patients and MethodsA total of 12 patients with primary systemic AL amyloidosis treated with HD-Mel with ASCT at Sapporo Medical University Hospital between 2004 and 2012 were evaluated. Patients with age older than 65 years, poor performance status or severe organ dysfunction were determined not to eligible for ASCT. The dose of melphalan for conditioning regimen was modified due to patients' condition. A dose of 200 mg/m2 was administered to patients in performance status (ECOG) 0 or 1, number of organ involvement 2 or less, serum creatinine <1.5 mg/dl, EF >50%, and BNP <200 pg/ml; otherwise 140 mg/m2. Hematological response (HR) and organ response (OR) were evaluated according to the Consensus Opinion from the 10th International Symposium on Amyloid and Amyloidosis. The Kaplan-Meier method was used to estimate event-free survival (EFS) and overall survival (OS); both of them were measured from the day of ASCT. ResultsTwelve patients were included in this study, 4 were women. The median age at transplantation was 54 years (range, 32 - 65 years). Involvement of 1 organ was present in 1 patient (8.3%), 2 organs were involved in 8, and 3 or more organs in the remaining 3. Ten patients had a lambda monoclonal protein, and the median percentage of plasma cells in the bone marrow was 2.5% (range, 0.2% - 9.6%). No patients received treatment before HDM/ASCT, except 2 patients treated high-dose dexamethasone or 1 course of VAD regimen before referring to our hospital. Six patients received 200 mg/m2 of melphalan and remaining six received reduced dose based on the criteria in Patient and Methods. Notably, it was possible to screen patients with only the value of BNP; i.e., all the patients who received 140 mg/m2 of melphalan by the criteria had a high level (more than 200 pg/ml) of BNP. The median time from diagnosis of AL to ASCT was 95 days (range, 47 to 195 days). The median number of CD34-positive cells infused was 3.55 x106/kg, and all patients were engrafted. The hematologic CR was achieved in 5 patients and PR in 2. The organ response was observed in 2 patients who achieved hematologic CR. The median EFS of all patients was 21.1 months (range, 3.4 to 70.8 months), and median OS was 21.1 months (range, 3.4 to 112.5 months). EFS and OS were significantly longer for patients who received 200 mg/m2 of melphalan that are same with patients who had BNP less than 200 pg/ml, compared with a lower dose of melphalan and higher level of BNP (EFS: 15.0 months vs not reached, p=0.0166; OS: 15.0 months vs not reached, p=0.0166). No TRM was observed. ConclusionsAL patients with less than 200 pg/ml of BNP can be safely performed HD-Mel with ASCT and expected longer survival. Disclosures:No relevant conflicts of interest to declare.

Nuclear Protein Dysregulation in Lymphoplasmacytic Lymphoma/Waldenström Macroglobulinemia

Waldenström macroglobulinemia (WM) is characterized by monoclonal gammopathy, usually IgM, in association with lymphoplasmacytic lymphoma (LPL). Little is known of the expression of nuclear proteins involved in B-cell development in LPL/WM. In this study, the expression patterns of PAX5/BSAP, MUM1/IRF4, and PRDM1/BLIMP1 were analyzed in plasma cells and lymphocytes in 29 cases of newly diagnosed LPL/WM by double immunohistochemical staining with CD138 and CD22. These patterns were compared with the expression profiles seen in normal bone marrow samples, reactive tonsils, and cases of plasma cell myeloma and marginal zone lymphoma. The median percentage of plasma cells coexpressing CD138 and PAX5 was significantly higher in LPL/WM compared with benign tissues (P = .001), marginal zone lymphoma (P = .002), and plasma cell myeloma (P < .0001), whereas the median percentage of plasma cells coexpressing CD138 and MUM1 was lower in LPL/WM than plasma cells in benign tissues (P = .02), marginal zone lymphoma (P = .001), and plasma cell myeloma (P = .0002). These findings show that a subset of plasma cells in LPL/WM demonstrates a nuclear protein expression pattern characteristic of the B-cell developmental program. Thus, the results better define the immunophenotypic profile of the neoplastic cells in LPL/WM.

High Incidence of Peripheral Blood Plasmacytosis In Patients with Dengue Virus Infection: a Prospective Study

AbstractAbstract 2772 Introduction:One of the characteristic features of dengue virus (DENV) infection is the occurrence of leukopenia and thrombocytopenia, probably resulting from virus induced bone marrow suppression. Despite the general bone marrow suppression, polyclonal peripheral blood plasmacytosis has occasionally been described in DENV infected patients. The frequency of peripheral blood (PB) plasmacytosis in patients with dengue infection, the origin of these plasma cells (PCs) and the mechanisms by which they appear in the blood are not known. We initiated this prospective observational study to quantify and describe the kinetics and phenotype of PB plasmacells (PCs) in these patients. Methods:Morphological examination of the peripheral blood smear was performed in 35 sequential returned travelers suspected of DENV infection, with a history of less than 14 days of fever. Flow cytometric (FC) analysis for the characterization and immunophenotyping of lymphocyte subsets and PCs was performed in 31 patients. Follow-up samples were available for 8 patients. Results:Our results show that PB plasmacytosis is a very common hematological finding in DENV infection, with extreme values of up to 36% of total white blood cells in some patients. Depending on the number of days since the onset of fever at presentation, PB plasmacytosis was observed in 64% to 73% of 28 patients with confirmed DENV infection, and in none of 7 patients with other febrile illnesses. PB plasmacytosis was the most pronounced before 7 days after onset of illness and declined rapidly thereafter, to completely disappear after 14 days of illness. The median percentage of PCs at day 7 was 2.5% (range 0–36%; 25–75 interquartile range: 0–8%). The median percentage of PCs was significantly higher in patients with secondary DENV infection than in patients with primary infection (4.5% versus 1.0%; p=0.05). Viral RNA was detectable in 18 of 28 DENV infected patients with a highly variable viral load, but there was no correlation between viral load and percentage of PCs. We found an excellent correlation between percentage of PCs as assessed by morphology and by flow cytometry (r2= 0.85). The majority of CD138+ PCs (89%) had a shared immunophenotype (CD45+/CD19−/CD56−), which differed from normal plasmacells which are generally CD19+. In all cases the PCs were polyclonal. Conclusion:PB plasmacytosis, characterized by a transient presence of polyclonal PCs in the circulation, is a common event in DENV infection and is probably the result of a vigorous humoral immune response to dengue. With an increasing number of travelers to areas where dengue virus is endemic, it is important also for hematologists to recognize this benign cause of sometimes extreme plasmacytosis, for which no invasive procedures such as bone marrow examinations are needed. Disclosures:No relevant conflicts of interest to declare.

Utility of CD81 Flow Cytometry (FC) Assessment In Diagnostic Evaluation of Plasma Cell (PC) Disorders

AbstractAbstract 3011 Background:CD81 is a tetraspanin cell surface protein that regulates CD19 expression in B lymphocytes and enables hepatitis C virus infection of human cells. Immunohistochemistry and FC have showed that CD81 expression is downregulated in multiple myeloma and PC lines (Luo, 2010). It appears also that normal PCs are CD81+ at a high percentage (Rawstron, 2008). However, information about CD81 utility in phenotypic diagnosis of PC disorders is scanty. We assessed the frequency and the diagnostic value of the FC detection of CD81 surface expression in multiple myeloma (MM), monoclonal gammopathy of undetermined significance (MGUS) and non-hematological malignancy subjects. Patients-Methods:A total of 84 bone marrow aspirates were analyzed in this study. These included 52 diagnosis/disease progression MM samples, 8 samples from MGUS patients and 24 samples from reactive plasmacytosis and ITP patients. A 4-color FC technique was used for PC analysis. Based on the European Myeloma Network guidelines (Rawstron, 2008), we evaluated expression of CD19, CD27, CD56 and CD81 on PCs identified by the CD38/CD45/CD138 combination. At least 100,000 events/tube were acquired, leading to a sensitivity limit of 0.1%. FC positivity threshold for studied antigens was set at 20%. Any deviation from the normal PC phenotype (CD19+CD27+CD56-) was considered as abnormal. Diagnostic tests also included FBC, biochemistry, beta-2 microglobulin, IgA, IgG, IgM, kappa and lambda light chain serum levels, serum protein electrophoresis and immunofixation, bone marrow aspirate and skeletal survey where required. Results:Median PC percentage was significantly higher in the bone marrow aspirate when compared to FC as expected [15.5(3-96)% vs. 2(0.11-53)%, p<0.001]. CD81 positivity was identified in 19% (10/52) of MM samples and 50% of MGUS (4/8) and normal PC samples (12/24). CD81 plasma cell expression was significantly different between normal and MM samples (median: 16.8(1.9-52.4)% vs. 2.5(0-90.4)%, p<0.001) and between MGUS and MM patients (median: 14.4(1.5-53)% vs. 2.5(0-90.4)%, p=0.001). Mean fluorescence intensity of CD81 was similar in the 3 groups. A positive correlation was found between CD81 and CD19 expression (rho=+0.596, p<0.0001) and between CD81 and CD27 (rho=+0.358, p=0.001) while CD56 expression was negatively correlated with CD81 (rho=-0.291, p=0.007). Flow cytometry provided correct diagnosis in 87% (73/84) of cases; 8 samples were identified as false positive and 3 as false negative. Subsequently, a Receiver Operating Characteristic (ROC) curve analysis was performed in order to assess CD19, CD27, CD56 and CD81 antigens' sensitivity and specificity in discriminating normal from malignant PCs (Figure); although CD81 shared similar sensitivity and specificity with CD27, CD19 was shown to have the highest sensitivity and specificity in detecting correctly PC identity. Conclusions:This study provides laboratory evidence that CD81 expression in PCs is strongly correlated with CD19, CD27 and CD56 expression. CD81 surface detection seems to characterize normal PCs in reactive plasmacytosis, ITP and MGUS. However, it has an inferior sensitivity and specificity, in discriminating normal from malignant PCs, when compared to CD19. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Extent of Hematologic Response Is Important in Determining Outcome in Transplanted Patients with Primary Amyloidosis AL. Importance of Achieving CR.

INTRODUCTIONStem cell transplant has been increasingly used in the initial therapy of newly diagnosed systemic AL. Introduction of the free light chain assay has made it easier to quantify responses in patients with AL. It is unclear whether the goal of therapy should be a hematologic response or, as in multiple myeloma, a complete response. This paper addresses the impact of the degree of response on outcome.PATIENTS AND METHODS282 consecutively transplanted patients are included in this analysis. None of the patients were excluded. There were 169 men (59%). 28% of the cohort have died. 69% had renal involvement, 51% cardiac involvement, 11% peripheral nerve involvement, 16% hepatic involvement. The median percentage of plasma cells at the time of transplant was 7. Echocardiographic analysis revealed a median septal thickness of 12 and a median ejection fraction of 65%. Patients ranged in age from 31 to 71 with a median of 57 years and were transplanted at a median of 4.2 months following histologic diagnosis of amyloidosis. 27% of patients received reduced intensity conditioning usually due to moderate cardiomyopathy or renal insufficiency. 201 patients achieved a hematologic response and 93 of these achieved a complete response. The criteria for response were reported in accord with the consensus definition for response established at The Xth International Symposium on Amyloid and Amyloidosis. A complete response required immunofixation negativity of serum and urine with a normal free light chain ratio. A hematologic objective response required a 50% reduction of serum and urine monoclonal protein with a 50% reduction in the free light chain value. Figure 1 shows the Kaplan Meier curves demonstrating the survival of all patients based on whether they achieved a complete response, partial response, or failed to achieve response. There were 93 CR, 108 PR, and 81 nonresponders. The differences in all three curves are significant at P<.001. Figure 2 demonstrates the same cohort of patients using a six month landmark analysis to exclude the effect of treatment related mortality on outcome. There were 86 CR, 91 PR, and 36 NR for a total of 213 patients. There was a difference in response rate based on conditioning intensity (p<0.01) and age (p=0.046). The median survival was only reached in the NR at 40.1 months and, in the landmark analysis the differences between all three survival curves were statistically significant.CONCLUSIONPatients who achieve a hematologic complete response following sct for AL do better than other patients. Patients who achieve an objective response have a superior outcome than patients who fail to achieve a hematologic response, in a landmark analysis at six months. It is unclear if consolidation chemotherapy should be offered to partial responders in an attempt to convert them into CR's. [Display omitted] [Display omitted]

Non-secretory multiple myeloma: a report of 13 cases with a review of the literature.

The clinical features of 13 patients with non-secretory myeloma from a series of 172 consecutive multiple myelomas are presented. The non-secretors survived significantly longer that the secretors, median 46 months versus 21 months (p less than 0.01). Non-secretory myeloma was associated with a higher incidence of neurological presentation, minimal lytic bone disease, a lower median percentage of plasma cells in the marrow and a lower incidence of hypogammaglobulinaemia. The median survival of the non-secretors with minimal lytic bone lesions was 74 months compared to 21 months for those with extensive bone disease. The superior survival of non-secretors is thus thought to be due to earlier presentation possibly as a result of a tendency to form symptomatic local tumours. Retrospective immunoperoxidase staining of stored tissue was performed in nine cases. In only one of these was a monoclonal immunoglobulin not detected indicating that true 'non-production' is rare. In four patients who produced a biochemically detectable paraprotein during the course of their disease and in whom immunoperoxidase data was available the immunoglobulin was of the same type. Immunoperoxidase staining may help in the initial diagnosis of non-secretory myeloma but did not contribute any prognostic information.