Plasma Cell Morphology Research Articles

Oncolytic Tanapoxvirus Recombinants Expressing Flagellin C or Mouse Interleukin-2 Are Capable of Regressing Human Triple-Negative Breast Cancer Xenografts in Immuno-Competent BALB/c Nude Mice.

Triple-negative breast cancer (TNBC) in humans is the most aggressive and deadly form of BC. Although TNBCs are about 15 percent of the total number of BC cases, they are associated with the highest mortalities. Current treatment options are limited, and most modalities are toxic and have not increased the 5-year survival rates of TNBC. Many oncolytic viruses are emerging as potential therapies for TNBC. In this study, two Tanapoxvirus (TPV) recombinants, one expressing FliC and the other expressing mouse interleukin-2 (mIL-2), were assessed for their efficacy in an immuno-competent xenograft mouse model. MDA-MB-231 tumors were planted in BALB/c nude mice, treated, made immuno-competent via adoptive transfer of splenocytes from healthy BALB/c donors, and then monitored for 40 days. TPV/Δ2L/66R/FliC and TPV/Δ66R/mIL-2 demonstrated significant tumor reduction (p = 0.01602 and p = 0.03890, respectively) compared to the reconstituted control (RC), whereas wtTPV did not. Pathological analyses of treated tumors revealed cells consistent with lymphocyte and plasma cell morphology in reconstituted mice treated with TPV recombinants. Anti-viral plaque reduction assays conducted using harvested serum from treated animals indicated the presence of anti-TPV antibodies in mice reconstituted and treated with TPV that were missing from immune-deficient nude mice, including those exposed to TPV and of statistically equivalent serum concentrations to normal BALB/c mice immunized against TPV. The results suggest immuno-deficient BALB/c nude mice can become immuno-competent via adoptive transfer of splenocytes from genetically identical donors and allow for testing of tumor xenografts in a competent model system. The TPV recombinants tested should be further studied for the potential treatment of human TNBC.

Machine Learning Models Predict Molecular Genetic Subtypes of Multiple Myeloma from Whole-Slide Bone Marrow Aspirate Smears

Multiple myeloma (MM) is a plasma cell neoplasm and the second most common hematologic malignancy. Current guidelines recommend multiple myeloma cases undergo karyotyping and fluorescence in situ hybridization (FISH) analysis on bone marrow biopsy samples to assess for specific recurrent genetic abnormalities. Results of this testing help to predict differences in patient prognosis over time and to guide appropriate selection of therapy. Refinements in risk stratification incorporated additional complex molecular testing which, along with karyotyping and FISH, are costly and not available to all patients. Myeloma cell cytomorphologies have been associated in a subset of cases with more aggressive disease, when plasmablastic, and with a subset of t(11;14) cases, when lymphoplasmacytoid. Nonetheless, cellular features as assessed by manual microscopy have not been shown to identify biologic subtypes of disease reproducibly and broadly, such that these features are not a component of current prognostic systems. Whether accurate risk-stratification information can be extracted from microscopic images of myeloma cells through machine-based approaches is uncertain. Thus, in this study, we tested the feasibility of using machine learning models to predict multiple myeloma molecular genetic subtypes from analysis of neoplastic plasma cell morphology on Wright-stained aspirate smears. We first improved upon a previously developed computational pipeline that identifies and classifies hematopoietic cells from scanned whole-slide images (400x) of bone marrow aspirate smears, including classification of plasma cells with 94% accuracy. Using this pipeline, we obtained images from all plasma cells (up to 68,569 plasma cells per slide) from aspirate smears of 18 patients without plasma cell neoplasms and 96 patients with plasma cell neoplasms (including 20 with t(11;14) and 23 with gain(1q); 44 with standard risk FISH and 22 with high risk FISH (t(4;14), t(14;16), del(17p), or >4 copies 1q+)). We then developed convolutional neural network (CNN)-based multi-instance machine learning models to perform patient-level classifications of disease status and molecular genetic classification from image-level analysis of plasma cell cytomorphology. These models demonstrated strong performance for classifying patients without versus with plasma cell neoplasms (AUROC 0.80), and are capable of making patient-level predictions of multiple myeloma molecular genetic subtypes (t(11;14), AUROC 0.73; gain(1q), AUROC 0.71) as well as prediction of FISH risk level (AUROC 0.68). Finally, by assessing cell attention scores and CNN model weights, this machine learning pipeline can assess which individual plasma cells and which specific morphologic features provided the most utility in the prediction of molecular genetic subtypes for individual patients, hence providing explainability for model output. Importantly, our findings suggest that cytomorphologic features of plasma cells on routine aspirate smear slides contain information, extractable through machine-based approaches, that correlates with molecular genetic subtypes employed for risk stratification. With further refinement these promising computational digital pathology models can potentially yield tools not only for use in low resource settings, but also provide a potential basis for development of multimodal models that incorporate and improve upon results of currently used risk stratification tools.

Comparison Of Histomorphology, Angiogenesis and Proliferation in Kappa and Lambda Restricted Plasma Cell Myelomas with Its Effect on Prognosis

Aims Of the Study: To study the type of light chain restriction and correlate it with the morphological parameters, proliferation index, angiogenesis and clinical parameters. Materials And Methods: The study includes 46 cases of myeloma diagnosed over the period of five years. The histomorphological features like plasma cell morphology, percentage of plasma cells and pattern of infiltration were studied. Immunohistochemistry for kappa and lambda light chains was done. Angiogenesis was assessed by calculating the microvessel density (MVD) using anti CD34 immunohistochemistry. Proliferation was assessed immunohistochemically using Ki67 by comparing with anti CD38 which was used to highlight the plasma cells. Results: The cases with kappa light chain restriction had significantly less of poorly differentiated morphology (7.4% vs 36.8%; p=0.02) and diffuse pattern of infiltration (22% vs 63%; p=0.01) compared to lambda. The kappa group also had lower MVD (9.9 vs 16.5; p=0.02) and proliferation index (4.7 vs 94; p=0.04) compared to the lambda. Conclusion: Therefore, the type of light chain restriction is also a prognostic factor in plasma cell myeloma.

A novel human multiple myeloma cell line with a 1q21 gain genetic abnormality and CKS1B overexpression.

Multiple myeloma (MM) is an incurable hematologic malignancy mainly due to its cytogenetic abnormalities. Therefore, it is important to establish permanent malignant MM cell lines as tools to develop more effective therapies. Pleural effusion cells of a 70-year-old patient was collected to establish the CZ2 cell line. Characterization of CZ2 was determined with nephelometry, flow cytometry, fluorescence in situ hybridization (FISH), and chromosomal microarray analysis (CMA). Western blotting analysis was adopted to determine protein expression. Cell viability was measured by the 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. We established and characterized a new MM cell line, CZ2. Using nephelometry and flow cytometry, cells with typical plasma cell morphology but not classical plasma cell phenotype were found to be non-immunoglobulin-secretary cells. FISH analysis of cells revealed a unique characteristic, namely, that there was only gain of the 1q21 region (1q21+). No other common cytogenetic abnormalities in MM, such as deletion of 17p (17p-), deletion of 13q (13q-), or translocation of immunoglobulin heavy chain (IgH), were observed. In addition, the original cell line maintains its single cytogenetic abnormality. Meanwhile, we observed through western blotting that CDC28 protein kinase regulatory subunit 1B (CKS1B), an adverse prognostic gene located in the 1q21 region, was highly expressed in CZ2. Knockdown of CKS1B reduced cell viability and also increased the levels of cleaved-poly(ADP-ribose) polymerase (cleaved-PARP) and cleaved-caspase3. CZ2 provides a suitable material for cellular and molecular studies of MM with only a 1q21 abnormality. This cell line is characterized by a gain of 1q21, and the high expression of CKS1B is an important model for studies of myeloma cell growth and drug resistance during therapy.

Waldenstrom Macroglobulinaemia with Signet Ring Cells: A Case Report

Waldenstrom Macroglobulinemia (WM) is an indolent lymphoproliferative disorder characterised by Immunoglobulin M (IgM) production and neoplastic lymphoid infiltrate. The morphology of the neoplastic cells show spectrum of maturation characterised by small lymphocytes, lymphoplasmacytoid cells and plasma cells. The infiltrate is predominantly lymphoid with relatively small population of plasma cells. The plasma cell morphology is commonly of mature type with basophilic cytoplasm, eccentric nucleus with clumped chromatin and perinuclear halo (hof). But incidence of signet ring cells in WM is very rare and only one case has been reported till date. Here, authors report an interesting case of a 61-year-old man who presented with on and off chest pain and later diagnosed as WM with signet ring cells. On examination, the patient was found to have anaemia and lymphadenopathy. Bone marrow aspirate cytology showed hypercellular particles and scattered signet ring like plasma cells with large globular cytoplasmic inclusions. Flow Cytometry (FCM) established the diagnosis by demonstrating the clonal nature of plasma cells and B-lymphoid cells. Immunofixation confirmed the presence of monoclonal protein of IgM lambda type. The cytoplasmic content in these signet ring plasma cells is probably the accumulated IgM due to the defect in releasing. Clustering of these signet ring cells in marrow may raise a suspicion of metastatic adenocarcinoma and should not be misinterpreted.

Multiple Myeloma: Modification and Adaptation of Plasma Cell Morphology Algorithm for the Prognosis of Congolese Patient

Objectives: To determine the multiple myeloma (MM) prognostic formulas applicable in Congolese with many aberrant and/or immature plasma cells according to GOASGUEN’s plasma cell morphology algorithm (PMA). Methods: The prospective, observational and descriptive study was carried out at the Ngaliema Clinic in Kinshasa from July 2016 to December 2019. The variables studied were the plasma cell types and the prognosis groups according to GOASGUEN and ZANDECKI. The nucleolus, the chromatin and the N/C ratio of 2 for each plasma cell encountered in multiple myeloma are examined in order by asking three successive questions as follows: 1) Is the nucleolus present? If yes, we denote 1; if not, note 0; 2) Is the chromatin thin? If yes, we score 1; if not we score 0; 3) The N/C ratio is greater than 6, if so, 1 is noted; if not, we note 0. We obtain a number with 3 successive digits preceded by the letter P for each plasma cell. Results: The overall rate of immature plasma cells and aberrant plasma cells in MM among Congolese was high at 26.6%. Their integration in the prognostic formulas showed for group A" = 22 patients, group B" = 5 patients and group C" = 32 patients. Examination of plasma cell types in the deceased showed that 14/17 had a P001 plasma cell count ≥ 15%. Conclusion: The high rate of aberrant and/or immature plasma cells, the P001 plasma cell type at a rate ≥ 15%, found mostly in group C" with poor prognosis, are responsible for the aggressive nature of MM in Congolese Blacks.

Plasma cell morphology as a trigger for the diagnosis of adult Fanconi syndrome.

Plasma cell morphology as a trigger for the diagnosis of adult Fanconi syndrome.

The Role of Plasmacytoid Dendritic Cells in Cancers.

Plasmacytoid dendritic cells (pDCs) are a special subtype of dendritic cells with the morphology of plasma cells. pDCs produce massive amounts of type I interferon (IFN-I), which was originally found to play an extremely pivotal role in antiviral immunity. Interestingly, accumulated evidence indicates that pDCs can also play an important role in tumorigenesis. In the human body, most of the IFN-α is secreted by activated pDCs mediated by toll-like receptor (TLR) stimulation. In many types of cancer, tumors are infiltrated by a large number of pDCs, however, these pDCs exhibit no response to TLR stimulation, and reduced or absent IFN-α production. In addition, tumor-infiltrating pDCs promote recruitment of regulatory T cells (Tregs) into the tumor microenvironment, leading to immunosuppression and promoting tumor growth. In this review, we discuss recent insights into the development of pDCs and their roles in a variety of malignancies, with special emphasis on the basic mechanisms.

Comment on ‘Vitiligo in a COVID‐19‐vaccinated patient with ulcerative colitis: coincidence?’: Type I interferons as possible link between COVID‐19 vaccine and vitiligo

We read with interest the article entitled "Vitiligo in a COVID-19-vaccinated patient with ulcerative colitis: coincidence?" by Aktas et al.1 The authors describe a 58-year-old man with ulcerative colitis who developed symmetrically distributed vitiligo facial patches around one week after receiving first dose of mRNA vaccine.1 the authors then ponder on the possible underlying immunological mechanism.

Relationship of Bone Marrow Plasma Cell Morphology with Cytogenetic Abnormalities in Patients with Multiple Myeloma

Introduction: Cytogenetics has become an integral part of Multiple Myeloma (MM) diagnosis and prognostication. A combination of conventional cytogenetics and interphase Fluorescence In Situ Hybridization (FISH) is currently used to stratify tumours into high, intermediate and standard risk disease. Aim: To compare the morphological details of plasma cells with cytogenetic abnormalities. Materials and Methods: The present retrospective cross sectional study was conducted at Department of Pathology Dayanand Medical College and Hospital, Ludhiana in three and a half year duration (1st January 2014 to 30th June 2017). All the diagnosed MM patients in whom cytogenetic was available were included and descriptive analysis was done using Chi-Square test and relevant statistical analysis using SPSS 21 version. Correlation was done with various morphological pattern (plasmacytic, plasma blastic). Results: Cytogenetic studies were performed on 42 cases using FISH technique (n=31, 81.6%) and GTG (Giemsa) banding (n=4, 10.5%). Three (7.9%) patients were tested with both methods. In the present study, all the patients (n=2,100%) with plasmablastic morphology who got tested with cytogenetics had del13q14.3 and none of the patients with normal genome (n=22) had plasmablastic morphology. Conclusion: Morphologic patterns of plasma cells and cytogenetic studies correlate well and can together help in better prognostication of MM patients.

Cytogenetic abnormalities and morphological changes of bone marrow in multiple myeloma: a pathological analysis of 151 cases

Objective: To investigate the relationship between six common cytogenetic abnormalities and bone marrow pathomorphology in multiple myeloma (MM). Methods: Bone marrow biopsy was performed on 151 newly-diagnosed MM patients. Meanwhile, myeloma cells were enriched by CD138 immunomagnetic beads, and then lq+, 13q-, 17p-, t(4;14), t (11;14), t (14;16) and other common genetic abnormalities were detected using interphase fluorescence in situ hybridization (FISH). The relationship between different genetic abnormalities and biopsy morphology was compared. Results: Of the 151 patients, 15 had extramedullary infiltration (9.9%). The rate of cytogenetic abnormalities was 76.2% (115/151), of which 1q+ accounted for 49.7% (75/151), 13q-39.1% (59/151), 17p-8.6% (13/151), t(4;14) 21.2% (32/151), t(11;14) 19.2% (29/151), and t(14;16) 2.0% (3/151). The proliferation patterns of MM plasma cells were nodular (48.3%, 73/151), interstitial (33.8%, 51/151) and diffuse (17.9%, 27/151). The morphology of plasma cells was mainly mature type (58.3%, 88/151), followed by juvenile type (20.5%, 31/151), intermediate type (15.9%, 24/151) and plasmacyte type (5.3%, 8/151). According to the mSMART risk stratification system, the proliferation pattern of myeloma cells in the high-risk group was mainly diffuse type, and the morphology was mainly immature and plasmacyte type. In the middle-risk group, mature type myeloma cells were mainly nodular proliferating. In the low-risk and negative group, mature type myeloma cells were mainly interstitial proliferating. There was no difference in the probability of different proliferation modes of intermediate type plasma cells in each group. Conclusions: The proliferation pattern and morphology of plasma cells in bone marrow biopsy combined with cytogenetic markers can more accurately predict the severity and prognosis of MM.

A proposed index of diffuse bone marrow [18F]-FDG uptake and PET skeletal patterns correlate with myeloma prognostic markers, plasma cell morphology, and response to therapy.

The investigation of a semi-quantitative index in the pelvis to assess for diffuse bone marrow (BM) [18F]-FDG uptake and the investigation of PET skeletal patterns in multiple myeloma (MM) patients, in accordance with prognostic markers, clonal plasma cell (cPC) morphology, and response to therapy. We prospectively analyzed [18F]-FDG PET/CT in 90 MM patients (newly diagnosed, 60; relapsed/refractory, 30). Among other PET/CT parameters, we calculated the ratio SUVmax pelvis/liver and examined for correlations with known MM prognostic parameters, cPC morphology (good vs. low/intermediate differentiation), and response to therapy. SUVmax pelvis/liver ratio was significantly lower for the group of good differentiation vs. intermediate/low differentiation cPCs (p < 0.001) and showed a positive correlation with BM infiltration rate, β2 microglobulin, serum ferritin, international staging system (ISS), and revised ISS; no significant correlation was found with hemoglobin. A cutoff value of 1.1 showed an excellent specificity (99%) and high sensitivity (76%) for diffuse BM involvement (AUC 0.94; p < 0.001). Mixed pattern and appendicular involvement correlated with poor prognostic features while normal pattern, found in 30% of patients, correlated with good prognostic features. Presence of ≥ 10 focal lesions negatively predicted for overall response (p < 0.05; OR 4.8). The CT component improved the diagnostic performance of PET. This study showed, for the first time, that cPC morphology and markers related with MM biology, correlate with SUVmax pelvis/liver index, which could be used as a surrogate marker for BM assessment and disease prognosis; PET patterns correlate with MM prognostic features and response rates.

The cut-offs for kappa/lambda ratio in bone marrow immunohistochemistry for the diagnosis of multiple myeloma

ABSTRACT Objective: The previously reported kappa/lambda ratio cut-offs for plasma cell clonality by immunohistochemistry were in different values. This study aimed to identify the cut-offs with the highest accuracy for the diagnosis of multiple myeloma. Methods: Bone marrow specimens consecutively recruited between January 2011 and March 2019. The patients were at least 18 years old with clinical suspicion of multiple myeloma and had bone marrow plasma cell ≥10% by CD138 immunohistochemistry. The index test was immunohistochemical stains for plasma cell kappa/lambda ratio. The reference standard to classify as multiple myeloma required meeting any of the following (1) kappa/lambda ratio ≤1/16 or ≥16, (2) abnormal plasma cell morphology, and (3) monoclonal immunoglobulin. Results: From 147 specimens (70 multiple myelomas and 77 reactive plasmacytosis), our cut-offs kappa/lambda ratio for light chain restriction at ≤1/7 or ≥9 yielded an area under the receiver operating characteristic curve of 1.0000 while ≤1/16 or ≥16 yielded 0.9643 (p-value 0.0212). Conclusion: The cut-offs for kappa/lambda ratio at ≤1/7 or ≥9 for diagnosis of multiple myeloma yielded the highest diagnostic accuracy. The suggested cut-offs could be of potential value in resource-limited laboratories.

Bone Marrow Morphology of Multiple Myeloma with Non-bone-related Extramedullary Disease

To explore the morphological characteristics of bone marrow cells of multiple myeloma with non-bone-related extramedullary disease and thier clinical significance. Bone marrow smears, peripheral blood smears and bone marrow biopsy sections as well as thier examination results of 20 cases of multiple myloma with non-bone-related extramedullary disease were collected at initial diagnosis in First Affiliated Hospital of Xi'an Jiaotong University from March 2013 to March 2016, and morphological characterisistes of bone marrow cells were analysed in combination with clinical data. The morphology of plasma cells in 20 patients showed 2 cytologic subtypes: primitive cell type (16 cases) and pleomorphic type (4 cases). Immature plasma cells were found in the 5 patients' peripheral blood smear, accounting for about 1%-4% of the number of peripheral blood cells. In bone marrow tissue, plasma cells hyperproliferated with nodular and packed type, and secondary myelofibrosis counted for 12 cases (60%). 13 MM patients whose non-bone-related extramedullary disease occurred during therapy were divided into 2 groups according to the marrow fibrosis density. The median time from diagnosis of MM to extramedullary lesions resulting from fibrosis 0-1 grade and 2-3 grade was 23.7±3.7 months and 10.5±3.2 months ahead of the former(P=0.025). Bone marrow plasma cell morphology of multiple myeloma with non-bone-related extramedullary disease at the initial diagnosis is mostly immature type, and plasma cells proliferate with nodular and packed type and accompanied by different degree of fibrosis. The degree of myelofibrosis indirectly reflects the degree of proliferation and malignancy of the bone marrow plasma cells, which maybe possess some value in predicting extramedullary disease in the early stages of the MM.

Comparing five diagnostic criteria for multiple myeloma: a retrospective study of 227 cases.

Several diagnostic criteria for multiple myeloma are used in clinical practice, and it can be difficult to reach a diagnosis when a patient's clinical presentation is consistent with one criterion but not with another. However, no study to date has compared the superiority of the different diagnostic criteria. The aim of this research is to compare the efficacy of five diagnostic criteria for multiple myeloma and to find the reasons for misdiagnosis of atypical multiple myeloma cases. A total of 227 multiple myeloma cases were retrospectively studied. The clinical data (including plasma cell morphology, flow cytometry, immunofixation electrophoresis, imaging information and clinical manifestations) were scrutinized and the reasons underlying the misdiagnoses analyzed. The Traditional Domestic criteria had the highest misdiagnosis rate due to the high fixed bone marrow plasma cell percentage and serum M-protein thresholds. The WHO criteria and the International Myeloma Working Group 2009 criteria exhibited relatively low misdiagnosis rates due to their lower bone marrow plasma cell percentage thresholds, flexible criteria and detailed end-organ damage descriptions. The 2003 International Myeloma Working Group criteria and the 2011 Chinese Myeloma Working Group criteria exhibited perfect performance, as each focused on monoclonal plasma cell proliferation and not on fixed bone marrow plasma cell percentage and serum M-protein thresholds. The 2003 International Myeloma Working Group criteria and the 2011 Chinese Myeloma Working Group criteria have advantages in diagnosing early or atypical multiple myeloma cases. To avoid misdiagnosing some atypical cases of multiple myeloma, attention should be paid to evidence of monoclonal plasma cell proliferation, and flow cytometry may be a useful tool for discovering monoclonal plasma cell proliferation. Advanced imaging techniques should be used to confirm any suspected or atypical findings on metastatic bone survey.

Plasma cell survival in the absence of B cell memory

Pre-existing serum antibodies play an important role in vaccine-mediated protection against infection but the underlying mechanisms of immune memory are unclear. Clinical studies indicate that antigen-specific antibody responses can be maintained for many years, leading to theories that reactivation/differentiation of memory B cells into plasma cells is required to sustain long-term antibody production. Here, we present a decade-long study in which we demonstrate site-specific survival of bone marrow-derived plasma cells and durable antibody responses to multiple virus and vaccine antigens in rhesus macaques for years after sustained memory B cell depletion. Moreover, BrdU+ cells with plasma cell morphology can be detected for 10 years after vaccination/BrdU administration, indicating that plasma cells may persist for a prolonged period of time in the absence of cell division. On the basis of these results, long-lived plasma cells represent a key cell population responsible for long-term antibody production and serological memory.

Dynamic Reorganization of the Cytoskeleton during Apoptosis: The Two Coffins Hypothesis.

During apoptosis, cells undergo characteristic morphological changes in which the cytoskeleton plays an active role. The cytoskeleton rearrangements have been mainly attributed to actinomyosin ring contraction, while microtubule and intermediate filaments are depolymerized at early stages of apoptosis. However, recent results have shown that microtubules are reorganized during the execution phase of apoptosis forming an apoptotic microtubule network (AMN). Evidence suggests that AMN is required to maintain plasma membrane integrity and cell morphology during the execution phase of apoptosis. The new “two coffins” hypothesis proposes that both AMN and apoptotic cells can adopt two morphological patterns, round or irregular, which result from different cytoskeleton kinetic reorganization during the execution phase of apoptosis induced by genotoxic agents. In addition, round and irregular-shaped apoptosis showed different biological properties with respect to AMN maintenance, plasma membrane integrity and phagocyte responses. These findings suggest that knowing the type of apoptosis may be important to predict how fast apoptotic cells undergo secondary necrosis and the subsequent immune response. From a pathological point of view, round-shaped apoptosis can be seen as a physiological and controlled type of apoptosis, while irregular-shaped apoptosis can be considered as a pathological type of cell death closer to necrosis.

In Vitro and In Vivo Activity of Fomitopsis Pinicola (Sw. Ex Fr.) Karst Chloroform (Fpkc) Extract Against S180 Tumor Cells

Background/Aims: Non-toxic fomitopsis is has been traditionally used in folk medicine in many countries for its anti-inflammatory and anti-vascular disease activities. The present study investigates the antitumor effect of Fomitopsis pinicola (Sw. Ex Fr.) Karst chloroform extract (FPKc) on S180 tumor cells in vitro and in vivo and we determined the underlying mechanisms. Methods: HPLC was employed to analyze the constituents of FPKc. In-vitro 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to quantify the growth inhibition of FPKc; Propidium iodide (PI) exclusion assay and scanning electron microscopy (SEM) were used to observe the damage on the cell membrane and the changes of the cell morphology; Staining with Hoechst 33342/propidium iodide (HO/PI) and the application of the Annexin V-FITC/PI analysis permitted to observe the cell death triggered by FPKc; DNA damage and cell cycle arrest were detected by flow cytometry; Rhodamine 123 (RH123) and Cytochrome C were used as dyes to investigate the alterations of the mitochondria. In-vivo tumor inhibition and mice survival time were determined. Results: The results of the HPLC assay indicated that FPKc might contain DA (dehydroeburiconic acid), PA (pachymic acid), and ES (ergosterol), at percentages of 0.25%, 17.8%, and 10.5%, respectively. Concerning the study of the biological function, the results showed that FPKc exhibited preferential and significant suppression of proliferation on specific cell lines including S180, HL-60, U937, K562, SMMC-7721, and Eca-109 cells, which induced plasma membrane and cell morphology damages, triggering S180 tumor-cells late apoptosis and leading to DNA damage and S phase arrest. Mitochondria were suspected to play a vital role in these changes. In vivo data indicated that FPKc inhibited the solid tumor growth and prolonged the survival time of tumor-bearing mice. Moreover, FPKc provoked only little damage on normal cells in vitro and also on normal tissues in vivo. Conclusion: FPKc inhibited S180 tumor cells growth and prolonged the lifespan of mice. In vitro, we found that FPKc induced S180 tumor cells apoptosis and cell cycle arrest, possibly via the mitochondrial pathway.

Intriguing Morphology of IgG/Lambda Secreting Myeloma Cells

Myeloma cells are known to show varied morphology and various types of nuclear or cytoplasmic inclusions. There are a few reports of myeloma with presence of pseudo-Gaucher type histiocytes; however myeloma cells itself resembling storage histiocytes is distinctly uncommon. We report images of plasma cells resembling storage cells from a case of IgG/lambda plasma cell myeloma. Hematopathologist must be aware of such varied morphology of plasma cells especially while dealing with extra medullary plasmacytomas.

Polychromatic flow cytometry is more sensitive than microscopy in detecting small monoclonal plasma cell populations.

There is an emerging role for flow cytometry (FC) in the assessment of small populations of plasma cells (PC). However, FC's utility has been questioned due to consistent underestimation of the percentage of PC compared to microscopy. A retrospective study was performed on bone marrow samples analysed by 8-colour FC. Plasma cell populations were classified as polyclonal or monoclonal based on FC analysis. FC findings were compared with microscopy of aspirates, histology and immunohistochemistry of trephine biopsies, and immunofixation (IFX) of serum and/or urine. FC underestimated PC compared to aspirate and trephine microscopy. The 10% diagnostic cutoff for MM on aspirate microscopy corresponded to a 3.5% cutoff on FC. Abnormal plasma cell morphology by aspirate microscopy and clonality by FC correlated in 229 of 294 cases (78%). However, in 50 cases, FC demonstrated a monoclonal population but microscopy reported no abnormality. In 15 cases, abnormalities were reported by microscopy but not by FC. Clonality assessment by trephine microscopy and FC agreed in 251/280 cases (90%), but all 29 discordant cases were monoclonal by FC and not monoclonal by microscopy. These cases had fewer PC and proportionally more polyclonal PC, and when IFX detected a paraprotein, it had the same light chain as in the PC determined by FC. FC was more sensitive in detecting monoclonal populations that were small or accompanied by polyclonal PC. This study supports the inclusion of FC in the evaluation of PC, especially in the assessment of small populations. © 2016 International Clinical Cytometry Society.