Evaluation of laboratory diagnostic tests for light-chain clonality and bone marrow findings in AL amyloidosis

Background@#Light-chain amyloidosis (AL) is the most common form of systemic amyloidosis. This study aimed to evaluate the usefulness of laboratory tests for light-chain clonality and bone marrow (BM) findings in AL amyloidosis. @*Methods@#We retrospectively enrolled patients newly diagnosed with AL amyloidosis on pathological examination who underwent a BM biopsy. Laboratory test data for light-chain clonality were collected and compared. Amyloid deposits were identified with H&E, Congo red, and PAS stains. @*Results@#We reviewed 98 patients with AL amyloidosis. Light chain clonality (λ, 64 cases; κ, 34 cases) was detected by serum immunofixation electrophoresis (IFE) (63.3%), urine IFE (70.8%), serum protein electrophoresis (PEP) (44.9%), urine PEP (44.8%), serum free light chain (SFLC) ratio (79.5%), and BM immunohistochemistry (IHC) (85.7%). Flow cytometric (FCM) assay identified aberrant BM plasma cells in 92.9% of cases. BM amyloid deposits were identified in 35 of the 98 cases (35.7%); 71.4% (25/35) were Congo red-positive, and 100.0% (35/35) were PAS-positive. @*Conclusion@#Laboratory tests for detecting light-chain clonality in AL amyloidosis in order of sensitivity include FCM assay for aberrant plasma cells, IHC for light chains on BM biopsy or clot section, SFLC ratio, and serum and urine IFE. Congo red staining of BM samples remains an important tool for identifying amyloid deposits in BM. Periodic acid-Schiff (PAS) staining can be useful in diagnosing some cases of Congo red-negative amyloidosis.

Effective and Practical Complete Blood Count Delta Check Method and Criteria for the Quality Control of Automated Hematology Analyzers

Background@#Delta checks increase patient safety by identifying automated hematology analyzer errors. International standards and guidelines for the complete blood count (CBC) delta check method have not been established. We established an effective, practical CBC delta check method and criteria. @*Methods@#We assessed five delta check methods for nine CBC items (Hb, mean corpuscular volume, platelet count, white blood cell [WBC] count, and five-part WBC differential counts) using 219,804 blood samples from outpatients and inpatients collected over nine months. We adopted the best method and criteria and evaluated them using 42,652 CBC samples collected over two weeks with a new workflow algorithm for identifying test errors and corrections for Hb and platelet count. @*Results@#The median delta check time interval was 1 and 21 days for inpatients and outpatients (range, 1–20 and 1–222 days), respectively. We used delta values at 99.5% as delta check criteria; the criteria varied among the five methods and between outpatients and inpatients. The delta percent change (DPC)/reference range (RR) rate performed best as the delta check for CBC items. Using the new DPC/RR rate method, 1.7% of total test results exceeded the delta check criteria; the retesting and resampling rates were 0.5% and 0.001%, respectively. @*Conclusions@#We developed an effective, practical delta check method, including RRs and delta check time intervals, and delta check criteria for nine CBC items. The criteria differ between outpatients and inpatients. Using the new workflow algorithm, we can identify the causes of criterion exceedance and report correct test results.

Immune Checkpoint Programmed Cell Death Protein-1 (PD-1) Expression on Bone Marrow T Cell Subsets in Patients With Plasma Cell Myeloma

Background@#Plasma cell myeloma (PCM) is caused by immune dysregulation. We evaluated the expression of immune checkpoint programmed cell death protein-1 (PD-1) on T cell subsets in PCM patients according to disease course and cytogenetic abnormalities.This study aimed to find a target group suitable for therapeutic use of PD-1 blockade in PCM. @*Methods@#A total of 188 bone marrow (BM) samples from 166 PCM patients and 32 controls were prospectively collected between May 2016 and May 2017. PD-1 expression on BM T cell subsets was measured using flow cytometry. @*Results@#At diagnosis, the median PD-1 expression on CD4+ T cells was 24.6%, which did not significantly differ from that in controls. After stem cell transplantation, PD-1 expression on CD4+ T cells was higher than that at diagnosis (P < 0.001), regardless of residual disease. PD-1 expression on CD4+ T cells in patients with residual disease after chemotherapy was significantly higher than that at diagnosis (P = 0.001) and after complete remission following chemotherapy (P = 0.044). PD-1 expression on CD8+ T cells was higher in PCM patients with cytogenetic abnormalities, including monosomy 13, 1q gain, complex karyotype, and hypodiploidy. @*Conclusions@#PD-1 blockade might have therapeutic potential in refractory PCM patients after chemotherapy, especially in those with high- or intermediate-risk cytogenetic abnormalities.

JL1 Antigen Expression on Bone Marrow Lymphoma Cells from Patients With Non-Hodgkin Lymphoma

BACKGROUND@#JL1, a CD43 epitope and mucin family cell surface glycoprotein, is expressed on leukemic cells. An anti-JL1 antibody combined with a toxic substance can have targeted therapeutic effects against JL1-positive leukemia; however, JL1 expression on bone marrow (BM) lymphoma cells has not been assessed using flow cytometry. We investigated JL1 expression on BM lymphoma cells from patients with non-Hodgkin lymphoma (NHL) to assess the potential of JL1 as a therapeutic target.@*METHODS@#Patients with BM involvement of mature B-cell (N=44) or T- and natural killer (NK)-cell (N=4) lymphomas were enrolled from May 2015 to September 2016. JL1 expression on BM lymphoma cells was investigated using flow cytometry. Clinical, pathological, and cytogenetic characteristics, and treatment responses were compared according to JL1 expression status.@*RESULTS@#Of the patients with NHL and BM involvement, 37.5% (18/48) were JL1-positive. Among mature B-cell lymphomas, 100%, 38.9%, 33.3%, 100%, and 25.0% of Burkitt lymphomas, diffuse large B-cell leukemias, mantle cell leukemias, Waldenstrom macroglobulinemia, and other B-cell lymphomas, respectively, were JL1-positive. Three mature T- and NK-cell NHLs were JL1-positive. JL1 expression was associated with age (P=0.045), complete response (P=0.004), and BM involvement at follow-up (P=0.017), but not with sex, performance status, the B symptoms, packed marrow pattern, cytogenetic abnormalities, or survival.@*CONCLUSIONS@#JL1 positivity was associated with superior complete response and less BM involvement in NHL following chemotherapy.

Clinical, Laboratory, and Bone Marrow Findings of 31 Patients With Waldenström Macroglobulinemia

BACKGROUND@#Waldenström macroglobulinemia (WM) is a subset of lymphoplasmacytic lymphoma (LPL) with bone marrow (BM) involvement and an IgM monoclonal gammopathy of any level. We aimed to identify the clinical, laboratory, and BM findings of patients with WM and to evaluate the usefulness of CD154 for the diagnosis and prognosis of WM.@*METHODS@#We reviewed the medical records and BM studies and/or flow cytometric immunotyping of 31 patients with untreated WM. Semiquantitative immunohistochemistry (CD20, CD138, tryptase, and CD154) of BM was performed.@*RESULTS@#Only six patients presented with symptoms of hyperviscosity syndrome. Eleven patients had solid cancer and/or another hematologic malignancy. Mast cells (MC) increased in all samples, with some in close contact with tumor cells. Tryptase-positive MC (17.1/ high-power fields [HPF], 1.2–72.0/HPF) and CD154-positive MC (8.6/HPF, 0.1–31.1/HPF) were observed. The high CD154-positive MC (≥8.6/HPF) group showed a lower overall five-year survival rate than the low CD154-positive MC (<8.6/HPF) group (71.9% vs. 100.0%; P=0.012). Flow cytometric immunophenotyping of BM aspirates showed increased B lymphocytes and plasma cells with a normal phenotype (CD138⁺/CD38⁺/CD19⁺/CD45⁺/CD56⁻).@*CONCLUSIONS@#Approximately one third of WM patients showed other malignancies and all patients had increased MC. Immunohistochemistry and flow cytometric immunophenotyping are useful for diagnosing WM, and increased CD154-positive MC can indicate poor prognosis.

Minimal Residual Disease Detection in Pediatric Acute Lymphoblastic Leukemia / 임상소아혈액종양

Minimal residual disease (MRD) status is the strongest independent prognostic factor for patients with pediatric acute lymphoblastic leukemia (ALL). Monitoring of the MRD status allows risk-adapted therapy as its absence or presence guides patient therapy and can result in significant treatment reduction or intensification, respectively. MRD assays should be sensitive (exceeding a threshold of 10−4 per current guidelines), specific, widely applicable, rapid, and technically feasible. Classical MRD assays that are widely used in pediatric ALL include multiparameter flow cytometry (MFC), which identifies aberrant immunophenotypes, and real-time quantitative polymerase chain reaction (RQ-PCR), which detects fusion transcripts or clonal immunoglobulin/T-cell receptor (IG/TCR) gene rearrangements. These assays have sensitivities of 10−3 to 10−5 and have been standardized internationally. However, each assay has its own pitfalls such as false negatives caused by immunophenotypic shifts in MFC, relatively limited applicability of the fusion transcript PCR, and the technical complexity associated with designing PCR for quantifying clonal IG/TCR gene rearrangements using allele-specific oligonucleotides. Next-generation flow cytometry, next-generation sequencing, and droplet digital PCR are expected to replace classical MRD assays, given their higher sensitivities (10−5 to 10−6) and accuracies as well as greater technical feasibilities. Before their incorporation into the standard practice for care for children with ALL, these assays require further exploration to ascertain whether their higher sensitivities are clinically relevant. Furthermore, standardization and quality assurance programs should be devised to enhance the clinical adoption of these new assays. Lastly, new targets should be identified to improve the monitoring of MRD; moreover, both the methodology and clinical significance of MRD evaluation should be revisited in the era of immunotherapy.

The First Korean Case of Epstein-Barr Virus-positive Natural Killer/T-cell Lymphoma That Progressed From Severe Mosquito Bite Allergy, With Coexistence of Hemophagocytic Lymphohistiocytosis

No abstract available.

First Case of Double T-Cell Receptor Alpha/Delta Rearrangements of t(11;14) and inv(14) and Subsequent JAK2 Rearrangement in a Patient With T-cell Acute Lymphoblastic Leukemia

No abstract available.

Reconstructed Three-Dimensional Images and Parameters of Individual Erythrocytes Using Optical Diffraction Tomography Microscopy

No abstract available.

Cluster Containing More Than 20 CD3-Positive Cells in Bone Marrow Biopsy Is a Candidate Prognostic Indicator in Peripheral T-Cell Lymphoma, Not Otherwise Specified

Assessment of bone marrow (BM) involvement in peripheral T-cell lymphoma, not otherwise specified (PTCL) is straightforward in cases of extensive involvement but difficult in cases of minimal to partial involvement. We evaluated the usefulness of CD3 as an immunohistochemical marker for assessing BM involvement in PTCL patients. BM biopsies of 92 PTCL patients were immunohistochemically stained for CD3, CD4, CD8, CD20, and CD56, and evaluated by two hematopathologists. CD3 positivity was graded according to the proportion of CD3-positive cells and the number of CD3-positive cells in a cluster. These criteria were used to determine the cut-offs at which significant differences in progression-free survival (PFS) and overall survival (OS) were observed. Multivariate analysis controlling the International Prognostic Index (IPI) score and its individual factors revealed that >20 CD3-positive cells in a cluster adversely affected PFS (relative risk [RR], 2.1; 95% confidence interval [CI], 1.0–4.3; P=0.047) and OS (RR, 2.4; 95% CI, 1.1–5.1; P=0.028) independent of IPI score. A cluster with >20 CD3-positive cells is a candidate indicator for BM involvement in PTCL.

Two Rare Cases of Therapy-Related Acute Lymphoblastic Leukemia in Patients With Plasma Cell Myeloma

No abstract available.

Unique Red Blood Cell Morphology Detected in a Patient with Myelodysplastic Syndrome by Three-dimensional Refractive Index Tomography

The three-dimensional (3-D) shape of erythrocytes is strongly associated with various diseases. However, conventional optical imaging approaches with Wright's staining only provide information on two-dimensional morphology. Here, we employed optical diffraction tomography (ODT), a label-free 3-D quantitative phase imaging technique, and observed uniquely shaped red blood cells (RBCs) in the peripheral blood of a patient diagnosed with myelodysplastic syndrome. Peripheral blood samples were collected when the patient visited our hospital for his two out-patient follow-ups in May 2018. The 3-D tomograms of randomly chosen RBCs were reconstructed using a commercial ODT setup. From the reconstructed 3-D RBCs, 37.5% and 32.8% of RBCs demonstrated cup-like shapes at the first and the second out-patient follow-up, respectively. Even though this is a single case report, the finding is novel and can be a potential dyserythropoietic feature found in peripheral blood.

POEMS Syndrome: Bone Marrow, Laboratory, and Clinical Findings in 24 Korean Patients

POEMS syndrome is a rare paraneoplastic syndrome, which includes polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes due to plasma cell (PC) neoplasm. Diagnosis of this disease is challenging because of its rarity and complex clinical manifestations. We attempted to identify the key clinical features and characteristic bone marrow (BM) findings of POEMS syndrome, by reviewing the medical records and BM analyses of 24 Korean patients. Frequent clinical manifestations included polyneuropathy (100%), monoclonal gammopathy (100%), organomegaly (92%), extravascular volume overload (79%), and endocrinopathy (63%). The BM analyses revealed mild PC hyperplasia (median PCs: 5.5%) and frequent megakaryocytic hyperplasia (88%), megakaryocyte clusters (88%), and hyperlobation (100%). Flow cytometry of BM aspirates using CD138/CD38/CD45/CD19/CD56 showed normal (67%, 4/6) or neoplastic PC immunophenotypes (33%, 2/6). A diagnosis of POEMS syndrome must be considered when a patient suspected of having PC dyscrasia shows the above clinical presentation and BM findings.

Bone Marrow Involvement of Epstein-Barr Virus-Positive Large B-Cell Lymphoma in a Patient with Angioimmunoblastic T-Cell Lymphoma

No abstract available.

Clinical and Cytogenetic Profiles of Rhabdomyosarcoma with Bone Marrow Involvement in Korean Children: A 15-Year Single-Institution Experience

BACKGROUND: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Alveolar RMS (ARMS) is characterized by FOXO1-related chromosomal translocations that result in a poorer clinical outcome compared with embryonal RMS (ERMS). Because the chromosomal features of RMS have not been comprehensively defined, we analyzed the clinical and laboratory data of childhood RMS patients and determined the clinical significance of chromosomal abnormalities in the bone marrow. METHODS: Fifty-one Korean patients with RMS < 18 years of age treated between 2001 and 2015 were enrolled in this study. Clinical factors, bone marrow and cytogenetic results, and overall survival (OS) were analyzed. RESULTS: In total, 36 patients (70.6%) had ERMS and 15 (29.4%) had ARMS; 80% of the ARMS patients had stage IV disease. The incidences of bone and bone marrow metastases were 21.6% and 19.6%, respectively, and these results were higher than previously reported results. Of the 40 patients who underwent bone marrow cytogenetic investigation, five patients had chromosomal abnormalities associated with the 13q14 rearrangement. Patients with a chromosomal abnormality (15 vs 61 months, P=0.037) and bone marrow involvement (17 vs 61 months, P=0.033) had a significantly shorter median OS than those without such characteristics. Two novel rearrangements associated with the 13q14 locus were detected. One patient with concomitant MYCN amplification and PAX3/FOXO1 fusion showed an aggressive clinical course. CONCLUSIONS: A comprehensive approach involving conventional cytogenetics and FOXO1 FISH of the bone marrow is needed to assess high-risk ARMS patients and identify novel cytogenetic findings.

Familial Hemophagocytic Lymphohistiocytosis Type 2 in a Korean Infant With Compound Heterozygous PRF1 Defects Involving a PRF1 Mutation, c.1091T>G

No abstract available.

A Case of Primary Bone Marrow Diffuse Large B-cell Lymphoma Presenting With Fibrillar Projections and Hemophagocytic Lymphohistiocytosis

No abstract available.

Granulomatous bone marrow involvement of Hodgkin lymphoma, nodular sclerosis type

No abstract available.

Frequency and Distinct Characteristics of Acute Myeloid Leukemia Lacking HLA-DR and CD34 Expression: Features Intermediate between Typical Acute Myeloid Leukemia and Acute Promyelocytic Leukemia

BACKGROUND: The objective of this study was to investigate the frequency and characteristics of HLA-DR⁻/CD34⁻ acute myeloid leukemia (AML) also known as acute promyelocytic leukemia (APL)-like AML. METHODS: This study included 683 newly diagnosed patients with AML. After exclusion of 211 patients with recurrent genetic abnormalities, one with acute panmyelosis with myelofibrosis, two with myeloid leukemia associated with Down syndrome, and two devoid of metaphase cells, we classified the remaining 467 patients as follows: group 1, HLA-DR⁺/CD34⁺ (typical AML); group 2, HLA-DR⁺/CD34⁻ or HLA-DR⁻/CD34⁺; group 3, APL-like AML. RESULTS: Group 1 comprised 294 patients, group 2 comprised 133, and group 3 comprised 40. Therefore, the frequency of APL-like AML among 683 unselected patients with AML was 5.9%. Group 3 patients had significantly higher leukocyte counts and bone marrow (BM) blast percentages, higher frequencies of normal karyotypes and NPM1 mutation, higher fractions of CD33-positive cells, higher concentrations of fibrin degradation products and D-dimers, lower frequencies of complex karyotypes, monosomal karyotypes and poor cytogenetic risk, lower fractions of CD13-positive cells, and lower fibrinogen concentrations, compared with group 1 patients. The values of the BM blast percentage, number of CD33-positive cells, and DIC score of the patients with APL-like AML were intermediate between those of the patients with typical AML and APL. CONCLUSIONS: This study demonstrates that APL-like AML is not uncommon, and it has characteristics distinguishable from those of typical AML. APL-like AML may have some pathophysiological relationships with APL, which need further investigation.

A Case of Acute Myeloid Leukemia Concurrent With Untreated Chronic Lymphocytic Leukemia

No abstract available.