Pitfalls in Assessing Measurable Residual Disease in Plasma Cell Myeloma: a Comparison between Common Laboratory Tests

Background: Morphological examination of the marrow requires a combination of a properly prepared bone marrow aspirate smear, a trephine biopsy section and an imprint of core biopsy. Some conditions often result in a dry tap and are best studied by marrow biopsy.The major drawbacks of biopsy sections are their thickness, precludingfine morphologic detail.The objective of this study was to compare the diagnostic accuracy, cellularity and cytomorphology from bone marrow biopsy core imprint smears with bone marrow aspiration smears.Materials and Methods: Imprint smears were prepared from 138 cases subjected to bone marrow examination. The bone marrow aspiration, imprint smears andbone marrow biopsy sections were examined and were categorized into five different groups on cytomorphological basis: Non-malignant alterations and normal marrow, Myeloid neoplasms, Plasma cell myeloma, myelo-infiltrative disease and absence of residual disease and further delineated into specific entities wherever necessary.Results: Out of 138 cases, non-malignant alterations and normal marrow was the largest subgroup (N=87, 63%), followed by myeloid neoplasms (N=26, 18.5%), Plasma cell myeloma (N=13, 9.4%), myelo-infiltrative disease (N=9, 6.5%) and absence of residual disease (N=3, 2.2%). The diagnostic accuracy of imprint smears was highest (92%) followed by biopsy sections (89.9%) and aspiration smears (87%). Kappa analysis showed strong agreement (>0.8) and p-value was statistically significant (<0.001) while correlating the final diagnosis.Conclusion: Imprint smear technique is a simple, rapid, inexpensive and reliable procedure. The routine use of imprint smear in the bone marrow examination will serve as an invaluable adjunct to bone marrow aspiration and biopsy.Journal of Pathology of Nepal (2015) Vol. 5, 739-746

Download Full-text

Marked Variability in Reported Minimal Residual Disease Lower Level of Detection of 4 Hematolymphoid Neoplasms: A Survey of Participants in the College of American Pathologists Flow Cytometry Proficiency Testing Program

Archives of Pathology & Laboratory Medicine ◽

10.5858/arpa.2014-0543-cp ◽

2015 ◽

Vol 139 (10) ◽

pp. 1276-1280 ◽

Cited By ~ 17

Author(s):

Michael Keeney ◽

Jaimie G. Halley ◽

Daniel D. Rhoads ◽

M. Qasim Ansari ◽

Steven J. Kussick ◽

...

Keyword(s):

Flow Cytometry ◽

Chronic Lymphocytic Leukemia ◽

Minimal Residual Disease ◽

Plasma Cell ◽

Myeloid Leukemia ◽

Residual Disease ◽

Lymphoblastic Leukemia ◽

Lymphocytic Leukemia ◽

Plasma Cell Myeloma ◽

Minimal Residual

Context Flow cytometry is often applied to minimal residual disease (MRD) testing in hematolymphoid neoplasia. Because flow-based MRD tests are developed in the laboratory, testing methodologies and lower levels of detection (LODs) are laboratory dependent. Objectives To broadly survey flow cytometry laboratories about MRD testing in laboratories, if performed, including indications and reported LODs. Design Voluntary supplemental questions were sent to the 549 laboratories participating in the College of American Pathologists (CAP) FL3-A Survey (Flow Cytometry—Immunophenotypic Characterization of Leukemia/Lymphoma) in the spring of 2014. Results A total of 500 laboratories (91%) responded to the supplemental questions as part of the FL3-A Survey by April 2014; of those 500 laboratories, 167 (33%) currently perform MRD for lymphoblastic leukemia, 118 (24%) for myeloid leukemia, 99 (20%) for chronic lymphocytic leukemia, and 91 (18%) for plasma cell myeloma. Other indications include non-Hodgkin lymphoma, hairy cell leukemia, neuroblastoma, and myelodysplastic syndrome. Most responding laboratories that perform MRD for lymphoblastic leukemia reported an LOD of 0.01%. For myeloid leukemia, chronic lymphocytic leukemia, and plasma cell myeloma, most laboratories indicated an LOD of 0.1%. Less than 3% (15 of 500) of laboratories reported LODs of 0.001% for one or more MRD assays performed. Conclusions There is major heterogeneity in the reported LODs of MRD testing performed by laboratories subscribing to the CAP FL3-A Survey. To address that heterogeneity, changes to the Flow Cytometry Checklist for the CAP Laboratory Accreditation Program are suggested that will include new requirements that each laboratory (1) document how an MRD assay's LOD is measured, and (2) include the LOD or lower limit of enumeration for flow-based MRD assays in the final diagnostic report.

Download Full-text

Performance of Diagnostic Tests for Plasma Cell Myeloma

Blood ◽

10.1182/blood-2018-99-110315 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 5570-5570

Author(s):

Gilda Zagoya ◽

Alejandro Ruiz-Argüelles ◽

Guillermo J. Ruiz-Arguelles

Keyword(s):

Plasma Cell ◽

Diagnostic Tests ◽

Laboratory Tests ◽

Light Chains ◽

Plasma Cell Myeloma ◽

Immunoglobulin Light Chains ◽

Predictive Values ◽

Sensitivity Specificity ◽

Total Immunoglobulin

Abstract Introduction. In vitro laboratory tests to diagnose of plasma cell myeloma vary considerably in sensitivity, specificity and positive and negative predictive values. We compared the performance of quantification of free immunoglobulin light chains with other methods used to detect a monoclonal protein in serum and/or urine. Objective. Compare sensitivity, specificity and positive and negative predictive values of several in vitro laboratory tests to detect monoclonal proteins in serum and urine in persons with plasma cell myeloma. Methods. 70 subjects with plasma cell myeloma and 50 controls were studied. Diagnostic tests included: (1) quantification of free and total immunoglobulin light-chains by immune assays; (2) immune fixation of heavy-and light-chains in serum and urine after gel electrophoresis; and (3) serum protein capillary electrophoresis. Diagnosis of plasma cell myeloma was based on clinical and radiological criteria, bone marrow examination and flow cytometric immune phenotyping with monoclonal antibodies to CD56, CD19, CD138 (CD38) and CD45. Sensitivity, specificity and positive and negative predictive values for each tests were estimated from contingency tables. Results. Quantification of free immmunoglobulin light-chains had the highest sensitivity and specificity and best positive and negative predictive values. Immune fixation of serum immunoglobulins was next best. Quantification of total immunoglobulin light-chains was the least sensitive and specific with the worst positive and negative predictive values. Quantitation of free light-chains had the additional advantage of objectivity (independence from observer bias). The immune fixation test was the most subject to observer bias. Conclusion. Quantification of free immunoglobulin light-chains had the best sensitivity, specificity and positive and negative predictive values for diagnosing plasma cell myeloma. (Table 1) Disclosures No relevant conflicts of interest to declare.

Download Full-text

Evaluation of a 5-Color Flow Cytometric Technique for Immunophenotyping and Quantitation of Plasma Cell Myeloma in Post-Therapy Bone Marrows.

Blood ◽

10.1182/blood.v108.11.5036.5036 ◽

2006 ◽

Vol 108 (11) ◽

pp. 5036-5036

Author(s):

Tove Isaacson ◽

Andrzej Jakubowiak ◽

Lloyd Stoolman ◽

Usha Kota ◽

William Finn ◽

...

Keyword(s):

Bone Marrow ◽

Flow Cytometry ◽

Minimal Residual Disease ◽

Plasma Cell ◽

Plasma Cells ◽

Residual Disease ◽

Plasma Cell Myeloma ◽

Color Flow ◽

Flow Cytometric ◽

Minimal Residual

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.

Download Full-text