Clonal Plasma Cells Research Articles

Extending Amyloidosis Diagnosis: A Rare Case of Peritoneal AL Amyloidosis Revealed by 18F-FDG PET/CT and 99mTc-PYP SPECT/CT.

We present a case with systemic amyloidosis secondary to immunoglobulin light-chain amyloidosis (AL amyloidosis), which 18F-FDG PET/CT and 99mTc-PYP scintigraphy revealed amyloid deposition in the peritoneum, omentum, and mesentery. AL amyloidosis is characterized by the proliferation of clonal plasma cells and increased production and extracellular accumulation of immunoglobulin light chains, leading to organ malfunction. Even though AL amyloidosis can affect the gastrointestinal system, peritoneal involvement is rarely observed. PET/CT and SPECT/CT images showed moderate to slightly increased tracer uptake in affected organs.

Comparison of 6 cycles of isatuximab with lenalidomide, bortezomib and dexamethasone (I-VRd) versus 3 cycles of I-VRd followed by one cycle of high-dose melphalan in newly diagnosed low-risk multiple myeloma. Protocol for a multicenter, prospective, randomized, phase II clinical trial (ELIAS-Trial)

Newly diagnosed multiple myeloma patients who are eligible for transplant usually receive several induction cycles of therapy, followed by one or two cycles of high-dose melphalan and autologous stem cell transfusion. In myeloma patients, high-dose melphalan improves overall survival and progression-free survival. However, melphalan exposure increases the risk of secondary malignancies and may lead to the transformation of residual myeloma cells into more aggressive clones, which may accelerate relapse. It remains to be determined whether low-risk patients also derive additional benefit from high-dose melphalan therapy compared with less toxic regimens. Here we publish the study protocol of a multicenter, interventional, controlled, randomized, prospective and open-label phase II trial to investigate whether patients with a low-risk profile (R-ISS stage I, characterized by a low tumor burden and the absence of negative cytogenetic findings or elevated LDH levels) and a standard-risk gene expression profile (using the SKY92 GEP assay) can be sufficiently treated with intensified consolidation regimens without prior high-dose melphalan chemotherapy. The primary objective is to assess whether three cycles of isatuximab, bortezomib, lenalidomide and dexamethasone (I-VRd) followed by stem cell apheresis and three additional cycles of I-VRd will result in a non-inferior rate of complete remission (CR) combined with MRD-negativity at week 40 after the start of induction therapy compared to three cycles of I-VRd followed by standard of care treatment (such as stem cell apheresis, high-dose melphalan, and autologous stem cell transplantation). We hypothesize that this approach could reduce toxicity, cost of treatment and the likelihood of the development of a more malignant plasma cell clone, while improving overall survival (OS) and progression-free survival (PFS) in newly diagnosed low risk myeloma patients.EU Trial Number2022-500453-16-00, https://clinicaltrials.gov/study/NCT05665140, identifier NCT05665140. Registration Date: 21.07.2022.

Guidelines for the diagnosis and management of multiple myeloma in China (2024 revision)

Multiple myeloma (MM), an incurable clonal plasma cell dysplasia, is the second most common hematological malignancy in many countries, mainly developing in the elderly population. With the emergence of novel agents and laboratory methods, the diagnosis and treatment of MM have been significantly improved. In this version of the "Guidelines for the diagnosis and management of multiple myeloma in China (2024 revision)", several examination items have been updated in the diagnostic section; the definition of ultra high-risk MM has been proposed in the risk stratification section; for patients with equal or more than second-line relapse, chimeric antigen receptor T cell therapy and a bispecific T-cell engager have been added; and the treatment recommendations have been listed at different levels based on the best available evidence.

Autologous stem cell transplantation for multiple myeloma patients whose myeloma-defining event was SLiM.

In 2014, the International Myeloma Working Group (IMWG) updated the criteria for diagnosing myeloma and added three additional criteria to the traditional Calcium elevation, Renal impairment, Anemia, Bone disease (CRAB) criteria, called the Sixty % marrow plama cells, Light chain ratio >60, Mri demonstates lytic lesions (SLiM) criteria (clonal bone marrow plasma cells ≥60%, involved to uninvolved free light chain ratio (FLCr) ≥100 and >1 focal lesion on magnetic resonance imaging (MRI)). We report on the outcomes of 30 patients who underwent autologous stem cell transplantation (ASCT) where therapy was initiated solely based on SLiM criteria and compared them to a matched cohort of 60 patients whose myeloma-defining event was CRAB. The SLiM cohort had a shorter median time to neutrophil (15 vs. 16 days, p = 0.049) and platelet (15 vs. 17 days, p = 0.0004) engraftment. The 36-month overall survival (OS) was 100% in the SLiM group and 93.27% in the control group (95% CI 83.06%-97.42%), with a trend towards longer OS in the SLiM cohort (p = 0.065). The 36-month progression-free survival (PFS) was 91.61% in the SLiM (95% CI 69.93%-97.87%) and 65.95% in the control group (95% CI 52.31%-76.53%). There was no difference in the PFS between the cohorts (p = 0.414). ASCT is efficacious and safe in MM patients transplanted only due to SLIM criteria. Early intervention in this asymptomatic cohort did not appear to result in deeper responses or better PFS compared to outcomes in symptomatic patients.

Novel CCL3-HMGB1 signaling axis regulating osteocyte RANKL expression in multiple myeloma.

Multiple myeloma (MM) is a clonal plasma cell proliferative malignancy characterized by a debilitating bone disease. Osteolytic destruction, a hallmark of MM, is driven by increased osteoclast number and exacerbated bone resorption, primarily fueled by the excessive production of RANKL, the master regulator of osteoclast formation, within the tumor niche. We previously reported that osteocytes, the most abundant cells in the bone niche, promote tumor progression and support MM bone disease by overproducing RANKL. However, the molecular mechanisms underlying RANKL dysregulation in osteocytes in the context of MM bone disease are not entirely understood. Here, we present evidence that MM-derived CCL3 induces upregulation of RANKL expression in both human and murine osteocytes. Through a combination of in vitro, ex vivo, and in vivo models and clinical data, we demonstrate that genetic or pharmacologic inhibition of CCL3 prevents RANKL upregulation in osteocytes and attenuates the bone loss induced by MM cells. Mechanistic studies revealed that MM-derived CCL3 triggers the secretion of HMGB1 by osteocytes, a process required for osteocytic RANKL upregulation by MM cells. These findings identify a previously unknown CCL3-HMGB1 signaling axis in the MM tumor niche that drives bone resorption by promoting RANKL overproduction in osteocytes.

Neurological manifestations of MGUS.

Monoclonal gammopathy of undetermined significance (MGUS) is a highly prevalent disorder characterized by a small bone marrow plasma cell or lymphoplasmacytic clone (less than 10%) that produces a small amount of monoclonal paraprotein without associated organ damage. Most patients with MGUS display benign behavior indefinitely, but some progress to an overt malignancy, and others develop organ damage despite no increase in monoclonal protein, resulting in the so-called MG of clinical significance (MGCS). This concept includes different disorders depending on the organ involved, and among them, MG of neurological significance (MGNS) constitutes a real challenge from both a diagnostic and therapeutic point of view. Diagnosis is particularly difficult due to MGNS's heterogeneous clinical presentation and common lack of a diagnostic biopsy. On the other hand, the complexity of treatment lies in the lack of standardized regimens and the common irreversibility of neurological damage. Focusing on the neurological manifestations of MGUS affecting the peripheral nervous system, we describe 3 illustrative cases from daily practice and discuss different aspects of diagnosis to treatment, emphasizing the need for multidisciplinary management based on the close collaboration of neurologists and hematologists.

Renal manifestations of MGUS.

Kidney disease is a common complication of monoclonal immunoglobulin (MIg)-secreting B-cell disorders and predominantly occurs in patients who do not meet the criteria for an overt hematological disease. To distinguish this situation from monoclonal gammopathy of undetermined significance, which lacks organ damage, the term monoclonal gammopathy of renal significance (MGRS) was introduced to depict the association of a small, otherwise indolent B-cell clone, with renal disease induced by the secreted MIg. The spectrum of renal disorders in MGRS is wide, encompassing both tubular and glomerular disorders, classified according to the composition of deposits and their ultrastructural pattern of organization. Renal lesions, independent of the tumor burden, are mostly governed by the molecular characteristics of the MIg variable domain and involve either direct (deposition or precipitation) or indirect (autoantibody activity, complement activation) mechanisms. The diagnosis, often suggested by careful analysis of renal and extrarenal symptoms, almost always requires histological confirmation by a kidney biopsy with light, immunofluorescence, and electron microscopy studies. Most patients do not have a known monoclonal gammopathy at presentation. Hematologic investigations should include serum and urine protein electrophoresis and immunofixation, serum-free light chain measurements, and bone marrow studies with flow cytometry and cytogenetics to determine the nature of the pathogenic clone (most commonly plasmocytic). Early diagnosis before the development of severe chronic kidney disease and rapid achievement of deep hematological response through clone-targeted chemotherapy (currently based on proteasome inhibitor and monoclonal anti-CD38 antibody-based combinations for plasma cell clones) are the main factors influencing long-term renal and patient outcomes.

MGCS: where do we stand today?

Monoclonal gammopathies of clinical significance (MGCS) are a heterogeneous group of disorders characterized by the presence of an indolent B-cell or plasma-cell clone producing a toxic monoclonal immunoglobulin resulting in end-organ dysfunction. MGCS is a clinicopathologic diagnosis that requires the demonstration of a monoclonal immunoglobulin in the correct clinical setting. The most common MGCS syndromes are renal, neurologic, and cutaneous, although hematologic and multi-organ MGCS syndromes are also increasingly recognized. Therapy most commonly targets the underlying clonal population; immunoglobulin-targeting therapies as well as complement and cytokine antagonists have emerged for selected MGCS syndromes and may be temporizing in a subset of patients. Other chapters review renal and neurologic MGCS; this chapter focuses on hematologic and multi-organ MGCS syndromes.

Clinical characteristics of monoclonal immunoglobulin-associated renal disease: a retrospective cohort study.

Clinical epidemiological data on monoclonal gammopathy of renal significance (MGRS) are lacking. In this retrospective observational study, MGRS was compared with B-cell or plasma cell malignancies (BCM/PCM) with renal involvement to clarify differences in their clinical features. Among the 1408 renal biopsies performed at our hospital, 25 MGRS and 18 BCM/PCM patients were identified. We investigated baseline characteristics and hematologic parameters of MGRS in reference to BCM/PCM using multivariable analysis. Cox proportional hazards analysis was performed for end-stage kidney disease (ESKD) and all-cause mortality. Comparing the MGRS with the BCM/PCM, meandifferences in creatinine level, estimated glomerular filtration rate, and clonal bone marrow plasma cell percentage were -2.76mg/dL, 27.72mL/min/1.73m2, and -18.86%, respectively (all P < 0.001). MGRS group had a predominance of glomerular lesions such as immunoglobulin-associated amyloidosis, cryoglobulinemic GN, and MIDD, and a lower risk of acute kidney injury/acute renal disease compared to BCM/PCM. During a median observation period of 23.7months, clone-directed therapy was performed in 32.0% of patients in the MGRS group, compared to 83.3% of patients in the BCM/PCM group. Compared with BCM/PCM, MGRS had a hazard ratio of 0.66 (95% confidence interval (CI) 0.23-1.92, P = 0.45) for ESKD and 0.33 (95% CI 0.11-1.03, P = 0.06) for death in multivariate logistic regression analysis. The clinical characteristics of MGRS and BCM/PCM with monoclonal immunoglobulin-associated renal disease are disparate. Understanding these differences is crucial for developing tailored clinical approaches and therapeutic strategies to improve patient outcome.

Differential Detection of Clonal Bone Marrow Plasma Cells in IgA Vs. IgG Monoclonal Gammopathy of Undetermined Significance and Its Association with Disease Progression

Differential Detection of Clonal Bone Marrow Plasma Cells in IgA Vs. IgG Monoclonal Gammopathy of Undetermined Significance and Its Association with Disease Progression

The Association between Rheumatological Diseases and Monoclonal Gammopathy of Undetermined Significance

Background: Monoclonal Gammopathy of Undetermined Significance (MGUS) is an asymptomatic clonal plasma cell disorder with the risk of progression to multiple myeloma (MM). Studies have shown that patients with rheumatological diseases (RD) are associated with an increased risk of progression of MGUS to MM. RD also exhibit higher prevalence of MGUS compared to the general population. Immunological dysregulation and chronic antigen stimulation from autoimmune activity are proposed mechanisms. We assessed the association between RD and MGUS development in the nationwide Veteran Health Administration database, thereby contributing to a deeper understanding of this relationship and its clinical implications. Methods: Patients with RD diagnosis (≥2 outpatient ICD 9/10 codes or ≥1 inpatient code) from 1999-2021 were included. Exclusions applied to patients with MGUS diagnosis (identified by a published natural language processing model), MM (ICD-9-CM/ICD-10-CM: C90/203.0/C90), non-Hodgkin lymphoma (202.85/C85), Waldenstrom's macroglobulinemia and other B-cell lymphomas (273.3/C88), or an amyloidosis (277/E85) prior to or &amp;lt;6 month of RD diagnosis. The first RD diagnosis was defined as the index date, with index age as the age at RD diagnosis. Follow-up time was from the index date to MGUS diagnosis/death/censoring (12/31/2021) which ever came first. Patients with RD were 1:2 matched to individuals without RD on their follow-up time (and determined their index date/age), followed by matching on their index age (±1 year). The same exclusion criteria were applied to individuals without RD. To account for potential bias due to more frequent care because of comorbidities, the cohort was further stratified by Charlson Comorbidity Index (CCI) at index date (high vs low based on median CCI). CCI was computed using ICD codes to identify diseases diagnosed &amp;lt;5 years before and 1 year after the index date. RD was categorized into antibody (Ab)-mediated and non-antibody (non-Ab) mediated RD. Stratified by CCI (high and low), multivariable logistic regression was conducted to analyze the association between RD (Ab and non-Ab mediated) and MGUS using multivariable-adjusted odds ratio (aOR). The covariates included sex, race (non-Hispanic White, non-Hispanic Black, Hispanic, Other), index age, body mass index (underweight, normal, overweight, obese), marital status (divorced/separated/widow, married, single), rurality (rural, urban), and CCI. Results: We analyzed data of 118,365 veterans; 39,455 had RD (80% non-ab-mediated, 20% Ab-mediated). Mean age was 54 years in both RD and non-RD groups by matching. Most patients were male (88.5% RD, 85.1% non-RD). Racial composition was similar: 56.5% non-Hispanic White, 26.0% non-Hispanic Black, and 6.9% Hispanic in the RD group, and 56.0%, 21.6%, 6.9% respectively in non-RD group. Median CCI was higher in the RD group (1 vs. 0). Most patients were obese (51.7% RD, 42.5% non-RD) or overweight (31.0% RD, 37.2% non-RD). In patients with high CCI (n=64,343), Ab-mediated RD (n=7,326) was associated with increased MGUS risk (aOR 2.1, 95% Confidence Interval [CI] 1.8-2.4, p&amp;lt;.0001) as was non-Ab mediated RD (n=20,830) (aOR 2.0, 95% CI 1.9-2.2, p&amp;lt;.0001) compared to patients without RD (n=36,187). In the low CCI group (n=54,022), non-Ab mediated RD (n=10,738) was associated with an increased risk of MGUS (aOR 4.4, 95% CI 3.3-5.7, p&amp;lt;0.0001) compared to patients without RD (n=42,723). There was not sufficient evidence to show that Ab-mediated RD (n=561) was associated with higher MGUS risk (aOR 2.6, 95% CI 0.49-13.7, p=0.26). Conclusions: In a retrospective cohort of US veterans, RD was associated with a higher incidence of MGUS. Both Ab-mediated and non-Ab mediated RD were associated with a higher risk of MGUS diagnosis in patients with higher burden of comorbidities. In patients with fewer comorbidities, only non-Ab-mediated RD was associated with MGUS, likely due to a small number of patients with Ab-mediated RD. Bias in MGUS assessment should be considered, as patients with RD may undergo more testing, leading to increased detection of MGUS. Future prospective studies are needed to evaluate this association and if presence of the RD increases risk of progression to MM.

Development of Novel Peripheral Blood Count-Based Prognostic Index for Multiple Myeloma

In multiple myeloma (MM), clonal plasma cells evade immune surveillance and proliferate within an inflammatory bone marrow microenvironment. During pathogenesis, monocyte-derived tumor-associated macrophages help myeloma cells to avoid apoptosis; effector T cell lymphocytes undergo senescence to enable preferential upregulation of their immunosuppressive regulatory T cell counterparts; and myeloma cells interact with hematopoietic stem cells to inhibit downstream megakaryocyte differentiation into platelets.1 Our prior research has suggested a prognostic role for the absolute monocyte count (AMC), absolute lymphocyte count (ALC), and platelet count as biomarkers. We have shown that abnormal AMC and decreased ALC and platelet count are associated with decreased overall survival (OS) among patients with MM at diagnosis and follow-up. Based on the easy accessibility of these peripheral blood markers and need for dynamic prognostication among patients with MM undergoing novel therapies, we created a categorical peripheral blood-based prognostic index for MM incorporating AMC, ALC and platelet count. We retrospectively evaluated this index in 10790 patients diagnosed with MM between 2000 and 2019 at Veterans Administration hospitals using cell counts obtained closest to diagnosis and up to 2.5 years thereafter. Patients were stratified into 3 levels based on a logarithmic risk score, where those with the lowest counts across all cell lines (AMC, ALC, and platelet count) were in level III and those with counts approaching normalcy were in level I. At diagnosis, 8% of patients were in level III and had the highest risk of death (hazard ratio [HR] 2.04; 95% confidence interval [CI] 1.85-2.24; P &amp;lt; .01) compared to those in levels I (HR 1.15; 95% CI, 1.08-1.23; P &amp;lt; .01) and II (HR 1.37; 95% CI, 1.28-1.46; P &amp;lt; .01). Moreover, the risk of inferior OS associated with level III status persisted during treatment and follow-up and existed independently of other known risk stratification tools (including Charlson comorbidity index, lactate dehydrogenase, International Staging System classification). With further validation, our findings support the use of our novel prognostic index, which potentially reflects the underlying tumor microenvironment, as an available tool for risk stratification during the MM disease course.

The Prevalence of Blastocystis Hominis and Gastrointestinal System Parasites in Patients With Newly Diagnosed Multiple Myeloma Diagnosis

Introduction: Multiple myeloma (MM) is a hematological malignancy characterized by the presence of abnormal clonal plasma cells in the bone marrow. Immunodeficiency seen in patients with multiple myeloma (MM) is a serious problem. Blastocystis sp. is found in the gastrointestinal tract and can infect humans. Background/ Aims: In our study, we compared the prevalence of B.hominis and other parasites with the control group and patients who had recently been diagnosed with multiple myeloma. Material-Methods: Ninety-five multiple myeloma patients from our center and 95 volunteers as a control group were included in our study. The patients did not have any symptoms when stool samples were taken. For B.hominis, three consecutive stool samples were examined by saline-lugol trichrome staining and formalin-ethyl acetate concentration. Data were recorded and analyzed using SPSS 25.0. Results: Patients with newly diagnosed multiple myeloma and any of the patients in the control group did not have any parasites other than B.hominis. A significant difference was found between the newly diagnosed MM patients and the control group in terms of the number of B.hominis occurrences in the stool (p &amp;lt;0.001). Conclusions: According to this result, parasite load in stool increased in patients with MM. This result may reflect the suppression of the immune system of patients with MM. Accordingly, B.hominis should be considered as a causative agent in the presence of gastrointestinal symptoms that may occur during treatment in patients with MM.

Chimeric Antigen Receptor T Cells for the Treatment of Multiple Myeloma.

Multiple myeloma (MM), characterized by abnormal proliferation of clonal plasma cells, is an incurable hematological malignancy. Various immunotherapy strategies have emerged as an efficacious approach for the treatment of MM, including monoclonal antibodies, antibody-drug conjugates, bispecific antibodies, and chimeric antigen receptor T (CAR-T) cells. Anti-B-cell maturation antigen (BCMA) CAR-T cells have revolutionized the treatment of MM patients with relapsed/refractory disease and their clinical use was approved for the treatment of these patients. Despite this progress, the efficacy of CAR-T cells in MM is limited by the responsiveness of only a part of the treated patients, the relapse of other patients, the cost of the treatment and the diminished response in patients with prior exposure to anti-BCMA targeting agents. Ongoing clinical trials are evaluating the use of CAR-T cells at an earlier stage of MM disease and the use of CAR-T cells targeting other membrane antigens expressed on malignant plasma cells.

Diagnosis of canine B-cell chronic lymphoid leukemia with a CD21 negative phenotype using the LT21 clone CD21 antibody in flow cytometry: a case report

BackgroundChronic lymphoid leukemia (CLL) is a hematological disorder characterized by the clonal expansion of small mature lymphocytes that accumulate in the blood and bone marrow. CLL can arise from B-, T-, or natural killer cell clones. The cytological evaluation of blood smears is often the simplest and least invasive method for diagnosing lymphoid leukemia. Immunophenotyping is used to further subclassify the type of lymphoid leukemia.Case presentationA 15-year-old, 4.4-kg spayed female Shih Tzu was presented to the veterinary medical teaching hospital of Kangwon National University. Despite having a normal appetite and activity level, cervical and inguinal lymph node enlargement was noted on physical examination. Complete blood count revealed severe leukocytosis, severe lymphocytosis, and monocytosis. Splenomegaly, hepatomegaly, and lymph node enlargement were detected on radiographic and ultrasonographic examination. Immunophenotyping was performed using peripheral blood mononuclear cells (PBMCs). The majority of lymphocytes exhibited the following profiles: CD3−CD79a− (97.5%), CD4−CD8− (98.6%), CD21−CD79a− (98.4%), CD34− (0.1%), CD45+ (99.6%), major histocompatibility complex class II+ (99.5%), and CD14− (0.5%). Based on the immunophenotyping results, possible differentials considered included the following: the majority of lymphocytes may be natural killer (NK) cell clones, plasma cell clones, or show aberrant expression or loss of CD21 marker due to the neoplastic nature of the cells. Further flow cytometry was performed using antibodies against CD3, CD5, CD94, and granzyme B. The combined results indicated that the predominant lymphocyte subset in the PBMCs was CD3−CD5−CD21−CD94−granzyme B−. To confirm monoclonality and exclude the aberrant loss of CD markers, a polymerase chain reaction for antigen receptor rearrangement (PARR) assay was conducted. The PARR assay, using DNA from blood and lymph node samples, showed B-cell monoclonality. Immunocytochemistry using PBMCs showed that the plasma cell marker Multiple Myeloma Oncogene 1 (MUM1) was not expressed. Therefore, the diagnosis was confirmed to be B-cell CLL.ConclusionImmunophenotyping can help subclassify the type of lymphoid leukemia; however, as tumor cells can show aberrant expression or loss of the CD21 marker, combining immunophenotyping with the PARR assay could yield a more accurate diagnosis.

Genomic instability and genetic heterogeneity in aging: insights from clonal hematopoiesis (CHIP), monoclonal gammopathy (MGUS), and monoclonal B-cell lymphocytosis (MBL).

Aging is a multifaceted process characterized by a gradual decline in physiological function and increased susceptibility to a range of chronic diseases. Among the molecular and cellular mechanisms driving aging, genomic instability is a fundamental hallmark, contributing to increased mutation load and genetic heterogeneity within cellular populations. This review explores the role of genomic instability and genetic heterogeneity in aging in the hematopoietic system, with a particular focus on clonal hematopoiesis of indeterminate potential (CHIP), monoclonal gammopathy of undetermined significance (MGUS), and monoclonal B-cell lymphocytosis (MBL) as biomarkers. CHIP involves the clonal expansion of hematopoietic stem cells with somatic mutations. In contrast, MGUS is characterized by the presence of clonal plasma cells producing monoclonal immunoglobulins, while MBL is characterized by clonal proliferation of B cells. These conditions are prevalent in the aging population and serve as measurable indicators of underlying genomic instability. Studying these entities offers valuable insights into the mechanisms by which somatic mutations accumulate and drive clonal evolution in the hematopoietic system, providing a deeper understanding of how aging impacts cellular and tissue homeostasis. In summary, the hematopoietic system serves as a powerful model for investigating the interplay between genomic instability and aging. Incorporating age-related hematological conditions into aging research, alongside other biomarkers such as epigenetic clocks, can enhance the precision and predictive power of biological age assessments. These biomarkers provide a comprehensive view of the aging process, facilitating the early detection of age-related diseases and hopefully enabling personalized healthcare strategies.

Light Chain (AL) Amyloidosis for Nephrologists - Treatment Standard.

Amyloidosis is a group of complex diseases caused by the misfolding and aggregation of proteins into amyloid fibrils. AL amyloidosis is one of the most prevalent forms of amyloidosis, characterized by the gradual proliferation of light chains from plasma cell clones. A growing body of evidence has contributed to our understanding of its pathogenesis, presentation, and clinical course. Increased recognition of its clinical sequelae has increased the prevalence of AL amyloidosis. Renal involvement, seen in up to 70% of cases, is particularly challenging due to its impact on quality of life and access to treatment options. Thus, early recognition of its unique sequelae, appropriate staging, and a comprehensive understanding of treatment options balanced by their organ toxicities are crucial to managing this disease. We review the current treatment standards and discuss novel developments in the pathophysiology, diagnosis, outcome prediction, and management of AL amyloidosis for the Nephrologist.

The role of therapeutic plasma exchange in plasma cell disorders.

Therapeutic plasma exchange (TPE) is an extracorporeal technique where patient's plasma containing pathogenic substances is separated and removed from the whole blood, while the cellular component is returned to the patient mixed with replacement solution via an apheresis machine. Due to its ability to remove pathogenic substances from plasma including immunoglobulins, TPE has proven efficacious in the management of various disorders across different medical disciplines, including plasma cell dyscrasias, which are characterized by the abundant secretion of non-functional immunoglobulins produced by an abnormally proliferating plasma cell clone. This review summarizes the current indications of TPE in plasma cell-related disorders and discusses its application, safety, and therapeutic effects.

Characterising how a single bout of exercise in people with myeloma affects clonal plasma cell and immune effector cell frequency in blood, and daratumumab efficacy in vitro

Multiple myeloma is a haematological cancer characterised by the accumulation of clonal plasma cells in the bone marrow and is commonly treated with daratumumab, an anti-CD38 monoclonal antibody immunotherapy. Daratumumab often fails to induce stringent complete responses, due in part to resistance to antibody-dependent cellular cytotoxicity (ADCC) exerted by natural killer (NK)-cells and monocytes. Exercise bouts undertaken by healthy people induce lymphocytosis in blood, including to NK-cells and B-cells, but the effects of exercise are unknown in myeloma patients. In addition, whether exercise mobilises plasma cells has not been adequately investigated, and as such the potential impact of exercise on daratumumab treatment is unclear. In this exploratory pilot study, n = 16 smouldering multiple myeloma participants enrolled and n = 9 completed the study which comprised a bout of cycling 15% above anaerobic threshold for ∼30-min, with blood samples collected pre-, immediately post-, and 30-min post-exercise. Peripheral blood mononuclear cells were isolated from blood samples and incubated with the RPMI-8226 plasmacytoma cell line, with or without the presence of daratumumab to determine specific lysis using a calcein-release assay. Daratumumab-mediated cell lysis increased from 18.8% to 23.2% pre- to post-exercise, respectively (p < 0.001), owing to an increased frequency of CD3−CD56+CD16+ NK-cells (+348%), HLA-DR+CD14dimCD16+ monocytes (+125%), and HLA-DR+CD14+CD32+ monocytes (+41%) in blood (p < 0.01). However, overall, total plasma cells (CD38+CD138+) nor clonal plasma cells (CD38brightCD138+CD45−/dimCD19− with light-chain restriction) increased in blood (p > 0.05). Notably, we observed a 305% increase in NK-cells expressing CD38, the daratumumab target antigen, which might render NK-cells more susceptible to daratumumab-mediated fratricide – whereby NK-cells initiate ADCC against daratumumab-bound NK-cells. In conclusion, exercise modestly improved the efficacy of daratumumab-mediated ADCC in vitro. However, plasma cells were largely unchanged, and NK-cells expressing CD38 – the daratumumab target antigen – increased in blood. Future research should consider the optimal timings of exercise during daratumumab treatment in myeloma to avert exacerbation of daratumumab-mediated NK-cell lysis.

Cytogenetic abnormality in non-systemic light chain amyloidosis monoclonal gammopathy of renal significance: A field needs to be explored.

The role of cytogenetic abnormalities in non-systemic light chain amyloidosis monoclonal gammopathy of renal significance diseases still needs to be clarified. Bhutani etal. present the results of a study investigating the underlying plasma cell cytogenetic abnormalities in monoclonal immunoglobulin deposition disease (MIDD). The results show that translocation (11;14) is a common abnormality in MIDD and affects the presentation and outcomes. Commentary on: Bhutani etal. Translocation (11;14) is a common cytogenetic abnormality in clonal plasma cells in monoclonal immunoglobulin deposition disease. Br J Haematol 2024; 205:1860-1865.