Pure Red Cell Aplasia Associated with Plasma Cell Myeloma: Does Monoclonal Protein Inhibit Erythropoiesis?

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 642-642
Author(s):  
Neha Korde ◽  
Kelsey Loeliger ◽  
Olga Simakova ◽  
Adriana Zingone ◽  
Richard Childs ◽  
...  

Abstract Abstract 642 Pure red cell aplasia (PRCA) is a rare hematologic disorder characterized by selective inhibition of red cell precursors in the bone marrow. The pathogenesis of PRCA is unclear. Reported secondary causes of PRCA include thymoma, lymphoproliferative disorders (large granular lymphocyte leukemia, chronic lymphocytic leukemia), and viral infection such as human B19 parvovirus; however, in a large portion of patients the cause of PRCA is not able to be elucidated. In this study, we report a series of PRCA patients with unusual histopathological features and associated increase in clonal plasma cells that appear to represent a previously unrecognized PRCA variant associated with MGUS/plasma cell myeloma. We performed a retrospective analysis of bone marrow biopsies and aspirates from 50 patients diagnosed with idiopathic PRCA at the National Institutes of Health between 2001 and 2009. All samples underwent morphological, immunohistochemical and molecular analysis. Serum protein assays were performed on a cohort of patients that demonstrated increased plasma cells and/or light chain restricted plasma cells. In addition to the classical PRCA finding of marked erythroid hypoplasia with maturation arrest, we found 11/50 (22%) PRCA patients with the following atypical bone marrow features: hypercellularity with increased fibrosis and variable degree of plasmacytosis with light chain restriction and frequent aberrant CD56 or cyclin D1 expression, indicating clonality. Based on CD138 staining, 10 of the 11 (91%) patients had 10–20% plasma cells on marrow biopsies, while 1 patient demonstrated 5% plasma cells. Light chain restriction of plasma cells was morphologically demonstrated in 7/11 (64%) patients. 8/11 (72%) patients demonstrated M-proteins on serum protein electrophoresis (SPEP) and/or immunofixation; 6 of the 7 evaluable patients with M-proteins had a skewed serum free light chain (FLC) kappa/lambda (K/L) ratio. There were 7 IgG M-proteins, and the isotype of the M-protein was not defined for one patient. Mean M-protein concentration was 1.18 g/dL (0.6-2.5 gm/dL). Among the 3/11 (27%) patients without M-protein, 2 patients had a skewed FLC K/L-ratio (normal range 0.26–1.65), and 1 patient had a K/L ratio of 1.57. Based on these findings, 9/11 (82%) patients were diagnosed with plasma cell myeloma, 1 patient with MGUS, and clonality of plasma cells could not be demonstrated in 1 patient. In order to better understand underlying mechanisms, we performed an erythroid colony forming assay by co-culturing normal donor hematopoietic stem cells (HSCs) with serum from a PRCA patient containing M-protein versus serum from a normal donor. Compared to normal serum, colony cultures containing M-protein had a 43% reduction in CFU-E and BFU-E suggesting inhibition of erythroid colonies by the monoclonal protein. Clinically, response rates to daclizumab are increased in idiopathic PRCA compared to PRCA variant associated with MGUS/plasma cell myeloma, 10/23 (43%) vs. 0/6 (0%), respectively, (p=0.04). Among 3/11 patients receiving anti-myeloma therapy, 1 patient had resolution of PRCA and later became transfusion independent after bortezomib and 2 patients were lost to follow-up. Over 20% of patients originally diagnosed with idiopathic PRCA were shown to harbor clonal plasma cells and exhibit atypical histopathological marrow features. CFU-E and BFU-E colony growth from normal donor HSCs was inhibited by patient serum containin M-protein. Resolution of PRCA with transfusion independence was achieved in a patient treated with bortezomib based therapy. These findings point to a novel, previously not recognized pathogenetic mechanism of PRCA associated with relatively low plasma cell burden and demonstrate that these patients may benefit from myeloma based treatment strategies rather than standard immunosuppression. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3396-3396 ◽  
Author(s):  
Robert Kyle ◽  
Ellen Remstein ◽  
Terry Therneau ◽  
Angela Dispenzieri ◽  
Paul Kurtin ◽  
...  

Abstract Smoldering multiple myeloma (SMM) is characterized by a serum M protein ≥ 3g/dL and/or 10% or more of plasma cells in the bone marrow. However, the definition is not standardized, and it is not known whether both serum M protein levels and bone marrow plasma cell counts are necessary for diagnosis or if one parameter is sufficient. We reviewed the medical records and bone marrows of all patients from Mayo Clinic seen within 30 days of recognition of an IgG or IgA M protein ≥ 3g/dL or a bone marrow containing ≥ 10% plasma cells from 1970 to 1995. This allows for a minimum potential follow-up of 10 years. Patients with end-organ damage at baseline from plasma cell proliferation, including active multiple myeloma (MM) and primary amyloidosis (AL) and those who had received chemotherapy were excluded. A differential of the bone marrow aspirate coupled with the bone marrow biopsy morphology and immunohistochemistry using antibodies directed against CD138, MUM-1 and Cyclin D1 were evaluated in every case in order to estimate the plasma cell content. In all, 301 patients fulfilled either of the criteria for SMM. Their median age was 64 years and only 3% were less than 40 years of age; 60% were male. The median hemoglobin value was 12.9 g/dL; 7% were less than 10 g/dL, but the anemia was unrelated to plasma cell proliferation. IgG accounted for 75%, IgA 22%, and biclonal proteins were found in 3%. The serum light-chain was κ in 67% and λ in 33%. The median serum M spike was 2.9 g/dL; 11% were at least 4.0 g/dL. Uninvolved serum immunoglobulins were reduced in 81%; only 1 immunoglobulin was reduced in 31% and both were decreased in 50%. The urine contained a monoclonal κ protein in 36% and λ in 18% and 46% were negative. The median size of the urine M spike was 0.04 g/24h; only 5 (3%) were > 1 g/24h. The median bone marrow plasma cell content was 15 – 19%; 10% had less than 10% plasma cells, while 10% had at least 50% plasma cells in the bone marrow. Cyclin D-1 was expressed in 17%. Patients were categorized into 3 groups: Group 1, serum M protein ≥ 3g/dL and bone marrow containing ≥ 10% plasma cells (n= 113, 38%); Group 2, bone marrow plasma cells ≥ 10% but serum M protein < 3g/dL (n= 158, 52%); Group 3, serum M protein ≥ 3g/dL but bone marrow plasma cells < 10% (n= 30, 10%). During 2,204 cumulative years of follow-up 85% died (median follow-up of those still living 10.8 years), 155 (51%) developed MM, while 7 (2%) developed AL. The overall rate of progression at 10 years was 62%; median time to progression was 5.5 yrs. The median time to progression was 2.4, 9.2, and 19 years in groups 1, 2, and 3 respectively; correspondingly at 10 years, progression occurred in 76%, 59%, and 32% respectively. Significant risk factors for progression with univariate analysis were serum M spike ≥ 4g/dL (p < 0.001), presence of IgA (p = 0.003), presence of urine light chain (p = 0.006), presence of λ urinary light chain (p = 0.002), bone marrow plasma cells ≥ 20% (p < 0.001) and reduction of uninvolved immunoglobulins (p < 0.001). The hemoglobin value, gender, serum albumin, and expression of cyclin D-1 were not of prognostic importance. On multivariate analysis, the percentage of bone marrow plasma cells was the only significant factor predicting progression to MM or AL.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5067-5067
Author(s):  
Meletios Athanasios Dimopoulos ◽  
Evangelos Terpos ◽  
Maria Gkotzamanidou ◽  
Evangelos Eleutherakis-Papaiakovou ◽  
Magdalini Migkou ◽  
...  

Abstract Abstract 5067 The incidental finding of a monoclonal gammopathy during workup for various conditions or in the context of a routine check-up is increasingly common. Several “patients” are then referred for diagnostic evaluation of their monoclonal gammopathy and additional workup is needed. It has been proposed that a bone marrow (BM) aspirate and biopsy is indicated when the monoclonal protein (M-protein) is ≥1.5 g/dL, when abnormalities are noted in the complete blood cell count, serum creatinine level, serum calcium level, or radiographic bone survey, in individuals with non-IgG monoclonal gammopathy and in those with an abnormal serum free light chain (FLC) ratio. The aim of this study was to identify factors that could aid in the evaluation of individuals presenting with asymptomatic monoclonal gammopathy and in whom invasive diagnostic testing with a bone marrow biopsy is considered. Thus, we analyzed our database and identified patients who were referred to the Department of Clinical Therapeutics of the University of Athens, Greece, for evaluation of asymptomatic monoclonal gammopathy and in whom a BM trephine biopsy, a serum and urine protein electrophoresis (SPEP) with immunofixation and quantitative immunoglobulins were performed. SPEPs were scanned and M-protein was measured using imaging analysis software. Patients with a monoclonal M-protein ≥ 3 g/dl (30 g/L), i.e. those diagnosed with asymptomatic/smoldering myeloma (SMM) or Waldenstrom's macorglobulinemia based on the standard criteria, were not included in the analysis. Clonality of BM plasma cells or lymphoplasmacytes was assessed by immunohistochemistry. Patients who eventually were diagnosed with plasma cell related conditions (i.e. amyloidosis, peripheral neuropathy, dermatoses, etc.) were also excluded from the analysis. Our analysis included 161 patients: 53% were females, median age was 64 year (range 33–89 years), 53% had a monoclonal IgG protein, 15.5% had a monoclonal IgA protein, 24% a monoclonal IgM protein and 2.5% had only a monoclonal light chain, while 4% had a biclonal protein. In 64% of patients the monoclonal light chain was kappa and in 37% was lambda. The median serum M-protein was 0.948 g/dl (range 0.1–2.99 g/dl); 52% of patients had an M-protein of <1 g/dl and 79% of <2 g/dl. Immunoparesis of at least one of the uninvolved immunoglobulins was present in 38% of cases and of both of the uninvolved immunoglobulins in 6%. Median BM infiltration by monoclonal plasma cells or lymphoplasmacytes was 15%. In 66.5% of individuals there was a BM infiltration of ≥10% by monoclonal plasma cells or lymphoplasmacytes, while in 10% of the studied cases the BM infiltration was ≥50%. A significant correlation of the size of M-protein and of the infiltration of the BM was found (R=0.592, p<0.001). However, 27% of patients with M-protein <0.5 g/dl had ≥10% clonal plasma cells or lymphoplasmacytes in their BM biopsies. The respective rates were 46% for those with M-protein <1 g/dl, 54% for those with M-protein 1.5 g/dl and 58% for those with M-protein <2 g/dl. Ninety per cent of those who had immunoparesis of at least one of the uninvolved immunoglobulins had ≥10% clonal plasma cells or lymphoplasmacytes. A BM infiltration of ≥10% was more frequent in individuals with a monoclonal IgG or IgA protein (72% and 80%, respectively) vs. 45% of those with a monoclonal IgM protein (p=0.015). Light chain isotype, age and gender were not predictive of the degree of BM plasma cell infiltration. In multivariate analysis, immunoparesis of at least one of the uninvolved immunoglobulins (OR: 6.45, 95% CI: 2.32–18, p<0.001), an IgG or IgA monoclonal protein (OR: 2.67, 95% CI: 1.1–6.4, p=0.028) and an M-protein of ≥1 g/dl (OR: 5.4, 95% CI: 2.23–13) were independently associated with the presence of ≥10% of clonal infiltration in BM biopsy. By combining the above risk factors we found that in those who had all three, 97% had ≥10% clonal cells in the BM biopsy, while in those with 0–1 of the above factors the probability to find ≥10% clonal cells was 43%. These findings indicate that even patients with low risk for BM infiltration by clonal plasma cells, may be diagnosed as SMM when a BM biopsy is performed. In conclusion, our data on a large number of individuals with asymptomatic monoclonal gammopathy who underwent a BM biopsy may indicate that the latter exam may provide useful information and could be included in the standard initial workup of these individuals. Disclosures: No relevant conflicts of interest to declare.


2020 ◽  
pp. 5310-5324
Author(s):  
S. Vincent Rajkumar ◽  
Robert A. Kyle

The monoclonal gammopathies, also referred to as paraproteinaemias, are a group of neoplastic (or potentially neoplastic) diseases associated with the proliferation of a single clone of immunoglobulin-secreting plasma cells. Monoclonal gammopathy of undetermined significance (MGUS) is an asymptomatic clonal plasma cell disorder characterized by a serum monoclonal (M)-protein level less than 30 g/litre, less than 10% of monoclonal bone marrow plasma cells, and no evidence of hypercalcaemia, renal insufficiency, anaemia, or bone lesions related to the plasma cell proliferative process, and no evidence of any other myeloma-defining events. Observation is the standard of care. Plasma cell myeloma is a clonal plasma cell malignancy that accounts for about 10% of haematological cancers. The cause is unknown. Fluorescence in situ hybridization of bone marrow plasma cells reveals specific primary translocations or trisomies in more than 90% of patients. The presence of del 17p, t(4;14), t(14;16), and t(14;20) occur in 20 to 25% of patients, and indicate higher-risk disease. Waldenström’s macroglobulinaemia (WM) is characterized by the presence of an IgM M-protein, 10% or more lymphoplasmacytic infiltration of the bone marrow, and symptoms such as anaemia, lymphadenopathy, and hyperviscosity. Rituximab, a monoclonal antibody directed against CD20, is used as initial therapy in conjunction with other active drugs. Ibrutinib is a new agent that is highly active against WM. The median survival is longer than 5 years. Immunoglobulin light-chain amyloidosis is a clonal plasma cell disorder characterized by tissue deposition of fibrils consisting of monoclonal κ‎ or λ‎ light chains. Standard treatment is with bortezomib, cyclophosphamide, dexamethasone, and autologous stem cell transplantation in selected patients.


Blood ◽  
1989 ◽  
Vol 74 (1) ◽  
pp. 380-387 ◽  
Author(s):  
F Cozzolino ◽  
M Torcia ◽  
D Aldinucci ◽  
A Rubartelli ◽  
A Miliani ◽  
...  

Plasma cells isolated from bone marrow (BM) aspirates of 12 patients with multiple myeloma (MM) and nine patients with monoclonal gammopathy of undetermined significance (MGUS) were analyzed for production of cytokines with bone-resorbing activity, such as interleukin-1 (IL-1), tumor necrosis factor (TNF), and lymphotoxin (LT). Culture supernatants of plasma cells from MM, but not from MGUS or normal donor, invariably contained high amounts of IL-1-beta and lower amounts of IL-1-alpha. With a single exception, TNF/LT biologic activity was not detected in the same supernatants. IL-6 was present in two of five supernatants tested. Normal B lymphocytes released both IL-1 and TNF/LT activities for four days after activation in vitro; however, production of these cytokines ceased at the final stage of plasma cell. Unexpectedly, the mRNA extracted from MM plasma cell hybridized with TNF- and LT- specific, as well as IL-1-specific probes, although the culture supernatants did not contain detectable TNF/LT biologic activity. When tested in the fetal rat long bone assay, MM plasma cell supernatants displayed a strong osteoclast-activating factor (OAF) activity, which was greatly reduced but not completely abolished by neutralizing anti- IL-1 antibodies. Anti-TNF or anti-LT antibodies were ineffective in the same test. We conclude that the IL-1 released in vivo by malignant plasma cells has a major role in pathogenesis of lytic bone lesions of human MM.


2019 ◽  
Vol 5 (4) ◽  
pp. 20190025
Author(s):  
Margaret Mwania ◽  
Naushad Karim ◽  
Sarah Wambui ◽  
Shamshudin Mohammedali ◽  
Allan Njau

Plasma cell myeloma is a bone marrow disorder characterized by neoplastic proliferation of plasma cells within the bone marrow replacing normal cells. We present a case report of a 25-year-old female with bilateral lower and upper limb pains. She had been seen in various health facilities for the past 2 years with progressively worsening disability. Skeletal survey revealed multiple osteolytic lesions in the appendicular skeleton resembling vanishing bone syndrome. Ultrasound-guided biopsy was done with histological diagnosis of plasma cell myeloma. This case is unique because of the young age at presentation, HIV seropositive status and atypical appearance of the lesions.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5495-5495
Author(s):  
Fatima Khan ◽  
Michael A. Linden ◽  
Nicole D. Zantek ◽  
Gregory M Vercellotti

Introduction Pure red cell aplasia (PRCA) is an uncommon complication of ABO-incompatible hematopoietic stem cell transplantation. It is characterized by anemia, reticulocytopenia and absence of erythroid precursors in a morphologically normal-appearing bone marrow. Most cases of PRCA resolve spontaneously within weeks to months. A small subset of patients has a protracted disease course requiring continued red blood cell (RBC) transfusions. There is no approved standard of care for PRCA. Tapering of immunosuppressives such as steroids and calcineurin inhibitors, plasma exchange, rituximab, and anti-thymocyte globulin have all been employed with varying success rates. We report a case of PRCA after ABO-incompatible transplant that responded remarkably to treatment with bortezomib. Case Presentation A 60 year old female received a non-myeloablative HLA-matched ABO-mismatched sibling donor transplant for lenalidomide-refractory myelodysplastic syndrome (5q-). She received fludarabine/busulfan conditioning and tacrolimus/methotrexate for GVHD prophylaxis. The donor was blood type A Rh-positive and the recipient was O Rh-positive. The patient's post-transplant course was complicated by delayed engraftment, thrombocytopenia and autoimmune hemolytic anemia. When seen at our institution 22 months post-transplant, she had transfusion-dependent anemia requiring RBC transfusions every 2-3 weeks and reticulocytopenia. Bone marrow biopsy showed erythroid aplasia and preserved hematopoiesis in other cell lines, dysplasia was absent and parvovirus testing was negative. The patient had evidence of complete engraftment based on short tandem repeat analysis. Blood typing reflected transfused type O Rh-negative RBCs. Neither A cells from the donor nor Rh-positive cells from the patient were detected. High titers of anti-A and anti-B isohemagglutinins were detected despite transfusion with washed RBCs to reduce passive transfer. She was treated with prednisone 60mg/day, rituximab 375 mg/m2 weekly x4 and methylprednisolone 1g weekly x6 without response. Eventually, all immunosuppressive medications were discontinued to induce a graft versus recipient response. Two subsequent bone marrow biopsies continued to show nearly absent erythropoiesis, and the rare erythroid cells present lacked the blood group A antigen. Since PRCA was thought to be due to the recipient's plasma cells making anti-A antibodies, bortezomib, a potent inducer of apoptosis in plasma cells, was initiated. Subcutaneous bortezomib 1.3 mg/m2 was administered weekly x4. The patient responded well to therapy. A month after completion of bortezomib, the patient's hemoglobin measured 12.1 g/dL, reticulocyte count was 174 x109/L and IgM and IgG anti-A titers were both < 1. Bone marrow biopsy showed relative erythroid hyperplasia, and the majority of the erythroid precursors expressed blood group A. The patient continues to do well and at the time of her most recent evaluation, her hemoglobin was 13.9 g/dL. She has also remained transfusion-independent. Discussion PRCA after major ABO-incompatible transplant is thought to be caused by persistence of recipient plasma cells that continue to secrete anti-donor isohemagglutinins. Antibody titers may remain elevated for a longer duration in patients receiving non-myeloablative preparatory regimens. Bortezomib is a proteasome inhibitor that selectively induces apoptosis in plasma cells. Bortezomib has been used successfully to treat anti-body mediated rejection in both renal and liver transplant patients. A case of PRCA following ABO-mismatched hematopoietic transplant that was successfully treated with IV bortezomib has also been reported. To our knowledge, this is the first reported case of isohemagglutinin-mediated PRCA after ABO-mismatched transplant that responded favorably to subcutaneous bortezomib. Limitation The lack of long-term follow-up data precludes any assessment about the durability and persistence of response to bortezomib. Conclusion Bortezomib is an effective treatment for patients with PRCA mediated by residual host isohemeagglutinins after ABO-incompatible hematopoietic transplantation. Disclosures: Off Label Use: Our presentation describes the use of bortezomib for treatment of pure red cell aplasia after ABO-incompatible hematopoeitic stem cell transplantation. Vercellotti:Sangart Inc.: Research Funding; Seattle Genetics, Inc.: Research Funding.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Zhongchuan W. Chen ◽  
Ioanna Kotsikogianni ◽  
Jay S. Raval ◽  
Christine G. Roth ◽  
Marian A. Rollins-Raval

Biclonal plasma cell myelomas producing two different isotypes of immunoglobulins are extremely rare entities; to date, the combination of IgD and IgM secretion by a biclonal plasma cell myeloma has not been reported. Bone marrow biopsy immunohistochemical studies in two cases revealed neoplastic plasma cells coexpressing IgD and IgM, but serum protein electrophoresis identified only the IgM monoclonal paraprotein in both cases. Biclonal plasma cell myelomas, while currently not well characterized in terms of their clinical behavior, should be distinguished from B-cell lymphoma with plasmacytic differentiation, given the different therapeutic implications. Both cases reported herein demonstrated chemotherapy-resistant clinical courses.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4854-4854
Author(s):  
James R. Cook ◽  
Eric D. Hsi ◽  
Raymond R. Tubbs ◽  
Sarah Worley ◽  
Mohamad A. Hussein

Abstract The expression of Cyclin D1 is dysregulated in approximately half of cases of plasma cell myeloma due to translocations, aneusomy, or other abnormalities. Recent studies using quantitative mRNA analysis have suggested that increased Cyclin D1 mRNA expression is associated with a favorable prognosis. Previous attempts to examine the significance of cyclin D1 protein expression by immunohistochemistry have been hampered by the use of antibodies with weak staining and high background. In this study, we employ a newly available, commercial antibody that gives superior staining in B5 fixed tissues. We performed immunohistochemistry for Cyclin D1 on bone marrow core biopsies from a series of 44 newly diagnosed plasma cell myeloma patients who were uniformly treated on a Phase II study of rituxan, melphalan and prednisone. 22 patients (50%) were positive for Cyclin D1, defined as any plasma cells with positive nuclear staining. Cyclin D1 positive and negative cases displayed no significant differences in the initial levels of β2m (3.6±0.5 mg/L vs. 3.5±0.5 mg/L, p=0.860), number of bone marrow plasma cells (63±5.5% vs. 47±6.2%, p=0.063), or proportion of cases classified as SWOG stage 3-4 (2 of 22 (9%) vs. 5 of 22 (23%), p=0.412). The cyclin D1 positive cases displayed a superior overall survival with an estimated 3-year survival of 95% for Cyclin D1 positive cases versus 56% for Cyclin D1 negative cases (p=0.032). The cyclin D1 positive cases also displayed a trend towards better progression-free survival (median progression free survival of 15.7 months for Cyclin D1 positive versus 12.8 months for Cyclin D1 negative, p=0.13). In a Cox proportional hazards regression model, used to compare the effect of Cyclin D1 protein expression on overall survival time while adjusting for stage, the Cyclin D1 positive patients continued to show a strong trend to better overall survival (p=0.062). This study demonstrates that cyclin D1 immunohistochemistry, which could be readily performed in most pathology laboratories, is capable of identifying a subset of plasma cell myeloma with a favorable survival. Additional studies are ongoing to determine if these results can be generalized to other forms of therapy. If confirmed, routine cyclin D1 immunohistochemistry at the time of diagnosis may offer important prognostic information that could identify lower risk patients for whom less intensive therapies might be appropriate.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5036-5036
Author(s):  
Tove Isaacson ◽  
Andrzej Jakubowiak ◽  
Lloyd Stoolman ◽  
Usha Kota ◽  
William Finn ◽  
...  

Abstract Multiparameter flow cytometry is a useful tool for comprehensive immunophenotyping of plasma cell myeloma, and has been proposed as a sensitive method for the evaluation of minimal residual disease in patients following treatment. This study aimed to assess the value of flow cytometry in quantitation of residual disease, in comparison to routine morphologic examination of first-pull bone marrow aspirate smears, in myeloma patients post-therapy. Heparinized bone marrow aspirates were obtained from 27 treated patients with plasma cell myeloma. Cells were prepared for 5-color flow cytometric analysis within 24-hours of specimen draw. Surface membrane staining with anti-CD19, CD20, CD38, CD45, CD56, and CD138 was followed by ammonium chloride lysis of red cells. Fixed and permeabilized cells were analyzed for cytoplasmic light chains to confirm clonality. Data were acquired using an FC500 flow cytometer (Beckman-Coulter), analyzed with CXP software with plasma cells isolated based on bright CD38+ or CD138+ expression. A median of 97,639 cellular events (range 14,279 to 262,508) were collected per analysis. Flow cytometric enumeration of plasma cells was compared to 500-cell differential counts of Wright-Giemsa-stained first-pull aspirate smears from the same cases. The median plasma cell count as determined by flow cytometry was 0.5% (range 0–7.9%). The median plasma cell count estimated by morphologic review was 8.0% (range 0–84.4%). Flow cytometry underestimated the plasma cell content in all but one case. Clonal plasma cells expressed CD38 and CD138 in all cases; 87.5% (21/24) coexpressed CD56, 25% (6/24) coexpressed CD45, and 4.2% (1/24) coexpressed CD19. None was positive for CD20. Although detection of minimal residual disease after therapy for acute leukemia is routinely achieved by flow cytometric analysis, successful quantitation of minimal residual disease in treated myeloma patients using flow cytometry remains limited as it usually underestimates the plasma cell content of bone marrow samples compared to routine morphology of first-pull aspirates. We have observed that this holds true for both pre-treatment and post-treatment specimens. Causes for the discrepancy may include hemodilution of second-pull aspirates used for flow cytometry, fragility and loss of plasma cells during preparation for flow cytometry, and incomplete disaggregation of plasma cells from bone marrow spicules. With improved outcome of treatments, better and more reliable methods of detection of minimal residual disease are needed for optimal prognostic stratification. We are currently validating alternative methods, which may offer more sensitivity while at the same time allow more objectivity, for assessing the amount of minimal residual disease in myeloma patients.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5319-5319
Author(s):  
Daniela Lakomy ◽  
Stephanie Lemaire-Ewing ◽  
Cedric Rossi ◽  
Jessica Borgeot ◽  
Jean-Noël Bastie ◽  
...  

Abstract Introduction The evaluation of multiple myeloma response to treatment as defined by international guidelines is currently based on morphologic examination of bone marrow plasma cells, serum protein electrophoresis (SPEP), immunofixation electrophoresis (IFE) and serum free light chain assay. For several years new tools are available as bone marrow plasma cell immunophenotyping and the HevyliteTM assay. HevyliteTM IgA assay provides an automated evaluation of serum heavy/light chain ratio (HLC) of the involved and uninvolved immunoglobulin (Ig) (i.e. IgAΚ/IgAλ). This is particularly interesting in IgA myeloma where the use of SPEP is limited due to a frequent comigration of monoclonal IgA with other proteins. We therefore compared the IgA quantification by Hevylite™ assay and the bone marrow plasma cell immunophenotyping for response evaluation and residual disease characterisation in IgA myeloma. Methods Hevylite™ assay, SPEP, IFE were performed in eleven IgA myeloma patients at different times: after induction chemotherapy, after the consolidation phase and after autologous stem-cell transplantation (ASCT). In the same time, minimal residual disease (MRD) assessment was performed on bone marrrow by multiparameter flow cytometry (MFC). Hevylite™ assay was performed on a Binding Site SPAplus analyser (Hevylite, Binding Site, Birmingham, UK) following the manufacturer recommendations. SPE and IFE were realized on Sebia Hydrasys analyser (Sebia, Evry, France) and results were read by two experienced biologists. Results 1. We found a perfect agreement between the IFE and immunophenotyping results at each time of evaluation, for positive results as for negative results. 2. The SPEP was contributive only in two patients and in these cases it was less sensitive than IFE. In the other patients, the monoclonal IgA migrated in beta region and/or as multiple bands, making the quantitative estimation difficult. 3. In all patients, when MRD by MFC was undetectable and IFE was negative, the HLC ratio was normal. 4. In 3 patients, HLC ratio was consistent with the IFE and MRD by MFC at each time of evaluation. Nevertheless, in 8 patients out of 11, while HLC ratio became normal, MRD by MFC and IFE were still positive. In all cases, the normalization of HLC ratio was followed, at the next step of evaluation, by the normalization of MFC and IFE. 5. In 5 patients, the normalization of HLC ratio occurred before ASCT, while IFE and MRD by MFC were still positive. Nevertheless, after ASCT, IFE and MRD by MFC became also negative, in accordance with the HLC ratio (Table 1). Conclusions During the evaluation of response to treatment of IgA myeloma, we observed a normalization of HLC ratio (Hevylite™ IgA assay) preceding the normalization of MRD by MFC and IFE. This could be explained by the fact that IFE and immunophenotyping provide very sensitive information but only on the monoclonal component. HLC ratio reflects the balance between the monoclonal and polyclonal Igs of involved and uninvolved isotype. A normalization of HLC ratio can be interpreted as an increasing polyclonal Ig proportion parallel with a decreasing monoclonal Ig proportion and may reflect the reconstitution of polyclonal plasma cells. If confirmed by other studies and long term follow-up, HLC ratio could be a non-invasive predictive marker of a good response in IgA myeloma. Disclosures: No relevant conflicts of interest to declare.


Sign in / Sign up

Export Citation Format

Share Document