Serum Immunofixation Electrophoresis Research Articles

Serum monoclonal immunoglobulin light-chain detection differs between immunofixation electrophoresis methods in patients with AL amyloidosis.

Serum immunofixation electrophoresis (IFE) is often performed for screening monoclonal proteins (M proteins) in immunoglobulin light-chain amyloidosis (AL amyloidosis). However, the performance of serum IFE for detecting M protein in AL amyloidosis patients is often insufficient. In this study, we examined the detection rate of serum M protein in newly diagnosed AL amyloidosis patients and analyzed differences in M protein detection between IFE methods. Among 60 patients newly diagnosed with AL amyloidosis, 22 had undetectable serum M protein by IFE with the Epalyzer2 system. Samples with undetectable M protein had significantly lower involved serum-free light-chain (iFLC) and a smaller difference between involved and uninvolved serum-free light-chain (dFLC) values than samples with IFE-detectable monoclonal light chains. When samples that tested negative for M protein by the Epalyzer2 system were retested by IFE with the HYDRASYS 2 system, 50% had IFE-detectable monoclonal light chains. The IFE system and reagents used may affect serum monoclonal immunoglobulin light-chain detection in AL amyloidosis patients, especially those with low iFLC or low dFLC samples. More attention should be paid to the performance of IFE systems, since it may affect the diagnostic and therapeutic evaluation of AL amyloidosis patients.

Characteristics of isatuximab-derived interference in serum protein electrophoresis and immunofixation, and an absence of sustained in vivo interference due to belantamab mafodotin and denosumab

ObjectivesSome therapeutic monoclonal antibodies, like daratumumab and elotuzumab, produce interfering monoclonal bands on serum protein electrophoresis (SPEP) and immunofixation electrophoresis (IFE). Whether other common therapeutic antibodies also produce interference has not been systematically evaluated. Design and methodsSPEP/IFE from patients receiving isatuximab (48 patients), belantamab mafodotin (BM; 41), and denosumab (41) were retrospectively reviewed for therapeutic antibody interference. Cases exhibiting isatuximab interference were quantified and the maximum duration of isatuximab effect was evaluated. To characterize band position, neat human serum was spiked with BM or denosumab at supratherapeutic concentrations. Band migration patterns were compared on SPEP and IFE, with band position expressed relative to other constant protein fractions. ResultsIsatuximab-induced IFE interference was common (81.3 % of evaluated patients) with a maximum observed duration of 8 weeks. 10.4 % of isatuximab patients had IgG kappa monoclonal gammopathies that co-migrated with the drug; this subset could benefit from HYDRASHIFT 2/4 isatuximab testing. 8.3 % of IFE cases were negative for an isatuximab band but showed large, endogenous M-spikes migrating elsewhere. All patients in this group expired within 1 year of this finding. We hypothesize that an inability to detect isatuximab in this setting corresponds to a large residual myeloma burden that reduces isatuximab serum concentration. This observation may serve as a negative prognostic factor. Spiking studies demonstrated that BM and denosumab produce interference in vitro, but sustained interference was not observed in >40 treated patients. ConclusionsTherapeutic antibody interference in patients receiving isatuximab is common, and can persist for at least 8 weeks after administration. >10 % of patients receiving isatuximab may benefit from HYDRASHIFT testing post-therapy. In contrast, BM and denosumab fail to produce sustained interference in treated patients.

External Quality Assessment and Clinical Laboratory Guidelines for Serum Protein and Immunofixation Electrophoresis in Korea

External Quality Assessment and Clinical Laboratory Guidelines for Serum Protein and Immunofixation Electrophoresis in Korea

Comparison of isotype-specific nanobody enrichment with matrix-assisted laser desorption/ionisation-time of flight method with serum immunofixation electrophoresis in detection of paraproteins

Comparison of isotype-specific nanobody enrichment with matrix-assisted laser desorption/ionisation-time of flight method with serum immunofixation electrophoresis in detection of paraproteins

Early M-protein immune reconstitution after autologous haematopoietic stem cell transplantation is a good prognostic marker for patients with high-risk cytogenetic multiple myeloma.

The presence of transient abnormal protein banding (M-protein immune reconstitution) in serum immunofixation electrophoresis after autologous haematopoietic stem cell transplantation in patients with multiple myeloma has been reported. The purpose of this study was to investigate the impact of post-transplant M-protein immune reconstitution on the prognosis of patients with multiple myeloma. M-protein immune reconstitution was observed in 25.9% (75/290) of patients. The CR rate and MRD negativity were higher in the M-protein immune reconstitution group (85.3% vs. 69.3%, p = 0.013, 81.9% vs. 66.5%, p = 0.014). Although there were no significant differences between the groups, the overall median survival time was longer in the M-protein immune reconstruction group (80 vs. 72 m, p = 0.076; not reached vs. 105 m, p = 0.312). Among patients in the cytogenetic high-risk group, the occurrence of M-protein immune reconstitution predicted better PFS and OS (80 vs. 31 m, p = 0.010; not reached vs. 91 m, p = 0.026). Additionally, in revised-International Staging System stage III patients, PFS and OS were better in those who achieved M-protein immune reconstitution (80 vs. 20 m, p = 0.025; 57 vs. 32 m, p = 0.103). The better prognosis of M-protein immune reconstitution patients may be associated with the acquisition of a deeper response. In high-risk patients, early acquisition of M-protein immune reconstitution may suggest a better prognosis.

Monitoring Minimal Residual Disease in Patients with Multiple Myeloma by Targeted Tracking Serum M-Protein Using Mass Spectrometry (EasyM).

We investigated both the clinical utilities and the prognostic impacts of the clonotypic peptide mass spectrometry (MS)-EasyM, a blood-based minimal residual disease (MRD) monitoring protocol in multiple myeloma. A total of 447 sequential serum samples from 56 patients with multiple myeloma were analyzed using EasyM. Patient-specific M-protein peptides were sequenced from diagnostic samples; sequential samples were quantified by EasyM to monitor the M-protein. The performance of EasyM was compared with serum immunofixation electrophoresis (IFE), bone marrow multiparameter flow cytometry (MFC), and next-generation flow cytometry (NGF) detection. The optimal balance of EasyM sensitivity/specificity versus NGF (10-5 sensitivity) was determined and the prognostic impact of MS-MRD status was investigated. Of the 447 serum samples detected and measured by EasyM, 397, 126, and 92 had time-matching results for comparison with serum IFE, MFC-MRD, and NGF-MRD, respectively. Using a dotp >0.9 as the MS-MRD positive, sensitivity was 99.6% versus IFE and 100.0% versus MFC and NGF. Using an MS negative cutoff informed by ROC analysis (<1.86% of that at diagnosis), EasyM sensitivity remained high versus IFE (88.3%), MFC (85.1%), and NGF (93.2%), whereas specificity increased to 90.4%, 55.8%, and 93.2%, respectively. In the multivariate analysis, older diagnostic age was an independent predictor for progression-free survival [PFS; high risk (HR), 3.15; 1.26-7.86], the best MS-MRD status (MS-MRD negative) was independent predictor for both PFS (HR, 0.25; 0.12-0.52) and overall survival (HR, 0.16; 0.06-0.40). EasyM is a highly sensitive and minimal invasive method of MRD monitoring in multiple myeloma; MS-MRD had significant predictive ability for survival outcomes.

Atypical Morphological Presentation of Neoplastic Plasma Cells: A Series of Five Cases

The diagnosis of Multiple Myeloma (MM) is made by demonstration clonal plasma cells in Bone Marrow (BM) aspiration/biopsy, in addition to assessing serum biochemical parameters, conducting radiological examinations, and considering the clinical presentation. In most cases, predominantly mature plasma cells are observed, along with scattered immature forms in the BM. Several morphological variants of plasma cells have been reported, including Auer rod-like inclusions, small lymphocyte-like cells, hairy cell-like cells, anaplastic variants, promonocyte-like cells, crystal-storing histiocytes, Burkitt-like cells, and blastoid cells. In this series of five cases, most showed a typical clinical presentation and laboratory findings suggestive of plasma cell dyscrasia. However, the morphology of each case exhibited unusual morphological variants, posing diagnostic challenges. These variants included Auer rod-like inclusions, small lymphocytes/lymph-plasmacytoid cells, hairy-like cells, multilobulated nuclei, and anaplastic variants mimicking dysplastic megakaryocytes, leading to various differential diagnoses. The age range of these cases was 57-76 years. Most of the cases presented with generalised dull aching body pain. Imaging studies revealed lytic lesions involving various parts of the bone, including the skull, ribs, vertebrae, and femur. Biochemical assays suggested the possibility of plasma cell dyscrasia. Two of the cases had primary Plasma Cell Leukaemia (PCL), which is a rare and highly aggressive plasma cell neoplasm. The anaplastic variant is associated with a poor prognosis, aiding in predicting treatment responses. However, due to the unusual morphological presentation, the diagnosis of MM or PCL was made after conducting ancillary studies such as Serum Protein Electrophoresis (SPEP), serum free light chain assay, Immunofixation Electrophoresis (IFE), and immunophenotyping through Immunohistochemistry (IHC) or flow cytometry

Urine immunofixation electrophoresis and serum free light chain analyses benefit diagnosis of multiple myeloma in orthopedic patients with normal serum total proteins, creatinine, calcium, and hemoglobin.

A substantial number of patients with multiple myeloma (MM) who have bone destruction are initially admitted into the orthopedic service at the hospital. However, routine laboratory testing usually fails to identify these patients, thus delaying optimal therapy. Therefore, there is a clear medical need for early diagnosis of MM in these patients. Between 2019 and 2021, 42 patients receiving treatment for orthopedic conditions had normal hemoglobin (Hb), total protein (TP), albumin (ALB), creatinine (CREA), and blood calcium (Ca) levels before their surgical procedure(s) but were subsequently pathologically confirmed to have MM, based on their presenting orthopedic symptoms. During the same period, 52 patients with orthopedic conditions were pathologically excluded from the diagnosis of MM and were recruited into our control group. Serum free light chain (sFLC) testing was performed in 94 consecutive patients in the orthopedic service using Siemens N Latex FLC kits. The levels of Hb, TP, ALB, CREA, and Ca were also measured. All 42 patients with MM were divided into group A (n = 25: κ proliferation) and group B (n = 17: λ proliferation) by the pathology department. There were no significant differences in levels of Hb, TP, ALB, CREA, and Ca between group A and group B and the control group. However, the sFLC κ/λ ratio of group A and B was also significantly different from that of the control group (P < .001). The results of serum immunofixation electrophoresis (IFE) testing demonstrated negative results in 14 cases (58.3%) in group A and 4 cases (25.0%) in group B. Some patients with orthopedic conditions who do not have typical MM laboratory results, such as those with abnormal Hb, TP, ALB, CREA, and Ca levels before their operation(s), actually have MM. MM should be highly suspected in patients with unexplained bone lesions and with an abnormal sFLC κ/λ ratio. Further tissue or bone marrow biopsy is needed in these patients even if serum and urine IFE results are negative and light chain ratio is normal.

Prognostic significance of serum monoclonal proteins based on immunofixation electrophoresis in B-cell non-Hodgkin lymphoma.

The presence of serum monoclonal components has been associated with poor outcomes in various hematological malignancies. The current study focused on exploring its prognostic role in B-cell non-Hodgkin lymphoma. Our study represented 314 patients with information on serum immunofixation electrophoresis at diagnosis that were available with B-cell non-Hodgkin lymphoma. IFE was positive in 61 patients (19%). Baseline features were comparable between pairs of groups, poor ECOG PS, B symptoms, advanced stage, and high-risk IPI score were significantly more frequent in the + IFE group. Shorter PFS and OS of B-NHL patients were observed in patients who presented at diagnosis with a + IFE, and IFE was the independent predictor of PFS and OS in multivariate analysis. Moreover, integrating IFE into the IPI-M1, IPI-M2, and IPI-M3 models improved the area under the curve for more accurate survival prediction and prognosis. Serum monoclonal proteins are significant prognostic indicators for newly diagnosed B-cell non-Hodgkin lymphoma that can early identify patients with poor prognosis and guide clinical treatment decisions.

Prevalence of MGUS in Rural Indian Population: Results of Simple (IMAGe-002A) Study

Introduction: The incidence of monoclonal gammopathies is rising across the globe. Although the prevalence of monoclonal gammopathy of undetermined significance (MGUS) has been evaluated in two hospital-based studies in India, no data exists on its prevalence in community-based settings amongst the rural Indian population. Objectives: To determine the prevalence of MGUS in a rural Indian population in a community-based setting. Methods: A cross-sectional study was conducted in an agrarian village in India covering a perimeter of 24.76Km and 4588.3 hectares with an 89.2% population coverage for adults more than 45y spending 12096 man-hours as part of SIMPLe ( Screening Intervention for Myeloma and Prevention of Lifestyl e diseases) study under the aegis of Indian Myeloma Academic Group e (IMAGe) registered vide CTRI/2023/03/051220. For the complete study population, demographic details, medical history, and blood samples were collected after a thorough medical examination. Hemogram, biochemistry (Liver and renal function tests), and serum protein electrophoresis (SPEP) were universally performed in all individuals. Serum immunofixation electrophoresis (SIFE) was performed for those with abnormal SPEP graphs (those with M spike and those with abnormal bulges in beta-2 or gamma region suspicious of MGUS). Patients with monoclonal protein on SPEP or SIFE were further assessed for any features of smoldering/ multiple myeloma. The data was analyzed using JMP ver. 16.0.0. Results: The prevalence of MGUS in the study population was 1.75%. The mean age of individuals with MGUS was 63.4±5.2y with male preponderance (60%). The mean Hb was 12.39±1.8g/dL with none of the patients having any renal dysfunction. None of the patients fit into the criteria for smoldering or multiple myeloma using IMWG criteria. Among those with MGUS, the distribution of Heavy and light chains was IgG - 83.33%, IgA - 16.67% with none having IgM/ IgD paraprotein, Kappa - 50%, and Lambda - 50%. Two individuals only had light chain MGUS. Conclusion: Our study provides a comprehensive description of the prevalence of MGUS in a rural community setting in India. The background prevalence is much less compared to the Western (both USA ~3% and European~5%) population.

Monitoring Minimal Residual Disease in Patients with Multiple Myeloma By Tracking Serum M-Protein Using Mass Spectrometry

Objective： We performed this retrospective real-world study to evaluate the clinical utility of blood-based mass spectrometry for longitudinal M-protein monitoring during the disease course of patients of multiple myeloma（MM）. Methods：We initially analyzed serial serum samples of 56 patients with MM by clonal peptide MS Method named EasyM MS, then we compared the MS results with those determined using serum immunofixation electrophoresis (IFE),multiparameter flow cytometry (MFC), next-generation flow cytometry (NGF), to establish the concordance between different disease-monitoring protocols. A sensitivity for MFC MRD negativity of at least 1×10 -4 anda sensitivity for NGF MRD negativity of at least 1×10 -5.Additionally, we determined the optimal cutoff value of EasyM MS negativity to satisfy both the sensitivity and specificity between MS and NGF, and explored the prognostic impact of MS-MRD status. Results：The median diagnostic age of 56 NDMM patients was 56 years old, including 34 males (60.7%). There were 38 patients with IgG type MP and 18 patients with IgA type MP. 47 patients (83.9%) chose to receive proteasome inhibitor - based induction therapy, and a total of 44 patients (78.6%) received first-line ASCT treatment.Among 56 MM patients，38 patients with IgG type MP can further identify IgG subclasses through mass spectrometry. Additionally, 56 patients with MM have successfully used MS to identify their unique clonal peptides of MP. 56 patients provided a total of 447 samples of serum and all sequential serum samples were successfully measured by using the MS method. The initial comparison of the performance of blood-based MS-MRD with that of the conventional M-protein diagnostic method IFE used . Among the 397 comparable results collected at similar timepoints, 70.8% (281/397) of the samples were both M-MRD- and IFE-positive, 3.3% (13/397) were both MS-MRD- and IFE-negative, 25.7% (102/397) were MS-MRD-positive and IFE-negative.Flow cytometry MRD was performed on 218 bone marrow aspirates in this cohort, including 126 analyzed with MFC and 92 analyzed with NGF. MS-MRD detection was also performed on comparable serum acquired at the same time points. The sensitivity of MS-MRD was 100.0% in comparison with both MFC and NGF, with specificity of 1.9% and 22.2%, respectively. Considering the overly high sensitivity of EasyM at a cutoff of dotp &amp;gt;0.9, we used the sensitivity of NGF as the standard for detection (i.e., a detection sensitivity ≤10 -5) and set the EasyM MS negative cutoff value using ROC analysis, determined to be &amp;lt;1.86% of that at first diagnosis. Using these assumptions, we again performed the aforementioned analyses comparing the sensitivity and specificity between EasyM and IFE, MFC, and NGF. Under this scenario, the sensitivity of EasyM remained high in comparison with IFE (88.3%), MFC (85.1%), and NGF (93.2%), but the specificity was also greatly increased to 90.4%, 55.8%, and 93.2%, respectively. We then divided patients into MS-positive and MS-negative groups according to whether they achieved MS-MRD negativity, and median PFS and OS were calculated for each group. The median PFS of the MS-positive and MS-negative groups was 20.6 (95% CI: 16.6, 24.6) and 61.8 (39.7, 83.9) months, respectively . The median OS was 55.7 (95% CI:31.8, 79.5) months for the MS-positive group and not reached (NR) for the MS-negative group ,Both mPFS and mOS were significantly longer among the MS-negative group compared with the MS-positive group (both p &amp;lt; 0.001). Conclusion：EasyM exhibits high sensitivity and minimally invasive technological advantages, and also has important significance in efficacy evaluation and prognosis evaluation. In the future, EasyM MS detection can be used as a minimally invasive MRD monitoring method based on peripheral blood in clinical practice.

Blood-Based Diagnostic Assay for λ Light Chain Amyloidosis through Quantification of an Amyloidogenicity-Indicating Neo-Epitope

Light chain amyloidosis (AL) is a rare, progressive, and often fatal protein misfolding disease. AL is caused by aberrant clonal plasma cell proliferation, where excess amounts of amyloidogenic monoclonal Free Light Chain (FLC) are produced, secreted into the circulation, misfolded and deposted as amyloid fibrils in various vital organs, such as the heart, kidney, liver, and nerves. The involed lambda (λ) FLC accounts for ~75% of all AL cases. Amyloidogenic FLCs (aFLCs) are believed to be the toxic species contributing to AL disease pathology. Specific quantification of aFLCs can provide critical guidance in clinical practice but has been hampered by the LCs sequence diversity as well as the lack of tests that are able to differentiate between circulating normal polyclonal FLCs and aFLCs. Contrary to non-amyloidogenic, aFLCs are kinetically and oftentimes thermodynamically unstable. aFLCs are prone to misfolding and formation of pathogenic conformations such as non-native structures, proteolytic fragments, soluble aggregates, and amyloid fibrils. We exploited such characteristics of aFLCs by applying limited proteolysis using Proteinase K, where less stable λ aFLC proteins readily yield a 23KDa fragment composed of the homodimeric LC constant domain (dLCCD) linked by a disulfide bond. Formation of the dLCCD fragment reveals a highly conserved, novel, cryptic epitope at the N-terminus of the fragment. We have generated monoclonal antibodies (mAbs) that explicitly bind to such novel epitope and developed immunoassays for the specific detection and sensitive quantification of λ aFLCs in biological samples. Western blot or Meso Scale Discovery (MSD) analyses were employed to detect and quantify dLCCD signal using the dLCCD mAbs on plasma samples from randomly selected, treatment naïve and λ-restricted cases with biopsy-proven AL amyloidosis before and after exposure to optimized proteolytic conditions. Tissue amyloid deposits of λ-type were confirmed in most AL cases. Informed consent for data and plasma sample collections were obtained from the Institutional Review Boards and in accordance with the Declaration of Helsinki. Multiple myeloma (MM) plasma samples of unknown LC restriction type, treatment or amyloid deposits status and normal volunteer control samples were purchased from BioIVT (USA). A set of representative results based on three runs are shown in Fig. 1. As little as 2 µL of biofluid was used for each assay. Upon limited proteolysis, dLCCD signal was detected in 32 of 35 AL plasmas, including two samples from patients with AL-associated IgM lymphoplasmacytic lymphoma (LPL). Of the three dLCCD negative AL samples, one presented with monoclonal IgAλ, and two cases were bi-clonal on serum immunofixation electrophoresis. dLCCD signal was not detected in 18 of 19 MM plasma samples. Similarly, dLCCD signal was undetectable in 23 normal plasmas. Overall, the dLCCD signals detected in AL plasmas were 10x-200x above that of normal control and most MM samples (Fig. 1). The low limit of quantification of the MSD assay was ~0.4 ng/dL (1.4 pM), with &amp;gt;500x dynamic range, enabling sensitive and robust quantification of λ aFLCs in biosamples. Analysis of Proteinase K recognition potential of the cleavage site of 389 λ LC sequences from the AL-Base, a database of amyloidogenic LC sequences (https://wwwapp.bumc.bu.edu/BEDAC_ALBase/) predicted that the dLCCD assay can detect λ aFLCs in up to 99% of λ AL patients, irrespective of the FLC sequences. This was confirmed with the 100% detection rate of the dLCCD signal in a validation cohort of 35 additional monoclonal λ-restricted AL samples. In summary, we have developed a quantitative blood-based immunoassay that is sensitive and highly specific for λ aFLC irrespective of the protein sequences. The preliminary data demonstrates the potential of our assay for AL diagnostics. Additional clinical applications for future exploration will include (i) monitoring and early detection of AL amyloidosis in plasma cell dyscrasias (monoclonal gammopathy of unknown significance, MM, and smoldering MM) and lymphoproliferative disorders, including LPL; and (ii) clinical management of patients with AL amyloidosis via the assessment and monitoring of minimal residual disease and therapeutic responses. The utility of the dLCCD assay in the quantification of λ aFLCs in bi-clonal AL cases warrants further investigation.

Multi-Center Clinical Validation of a Mass Spectrometry Immunoassay for the Diagnosis and Monitoring of Multiple Myeloma and Associated Disorders

Introduction: Mass spectrometry (MS) technology holds great promise for the investigation of monoclonal proteins (M proteins) in peripheral blood. We present results from a multi-center clinical validation study using quantitative immunoprecipitation MS (QIP-MS). QIP-MS combines isotype-specific immunopurification with matrix-assisted laser-desorption ionization MS, and offers automated, sensitive detection, isotyping and quantification of M proteins. It reports the mass/charge ratio (m/z) of the involved light chain, which serves as molecular fingerprint for monitoring the M protein. Methods: The study included 460 diagnosed monoclonal gammopathy (MG) patients (160 multiple myeloma (MM), 112 smoldering MM (SMM), 120 monoclonal gammopathy of undetermined significance (MGUS), 47 Waldenström's Macroglobulinemia (WM), and 21 AL amyloidosis), and 170 disease controls for assessing diagnostic sensitivity and specificity. Sixty-four MM patients with 439 follow-up samples and 10 WM patients with 91 follow-up samples were included to evaluate the ability of QIP-MS to detect M protein changes related to treatment. Median follow up was 19 and 15 months, respectively. Serum samples were retrospectively analyzed at three sites. QIP-MS was carried out using the automated EXENT® solution (in development, The Binding Site, part of Thermo Fisher Scientific). The assay's diagnostic sensitivity and specificity were calculated based on categorizing results as positive or negative. A positive result was defined in baseline samples as the presence of an M protein which was either an intact immunoglobulin ≥0.200 g/L or a light chain only. Results by QIP-MS were also compared to serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE). QIP-MS response categories were defined based on M protein changes per international guidelines criteria, and compared to response categories assigned by the treating physician. Complete response (CR) was defined as absence of the M-peak that was observed at baseline, using isotype and m/z value of ±4 as criterion for identity. Results: The overall diagnostic sensitivity of QIP-MS in this study was 95.0%: 93.3% for MGUS; 100.0% for SMM; 94.4% for MM; 100.0% for WM; and 71.4% for AL amyloidosis. The diagnostic specificity of the assay was 68.2%. QIP-MS identified an M protein in more MG patients compared to SPE: 437 (95.0%) vs 398 (86.5%). The positivity rate by QIP-MS vs SPE was 93.3% vs 84.2% in MGUS; 100% vs 92.9% in SMM; 94.3% vs 85.0% in MM; 100% vs 100% in WM and 71.4% vs 47.6% in AL amyloidosis. Method comparison demonstrated a Passing-Bablok slope of 0.8 to 1.2 between QIP-MS and SPE for the quantification of M proteins for each disease group and for each isotype, except for monoclonal IgM and in WM (slope of 1.58). In SPE-positive MG patients, the overall concordance between QIP-MS and IFE for M protein isotype was 97%. The overall concordance rate between QIP-MS response categories and standard response assignment was 55% for MM and 56% for WM: 48% for progressive disease (PD); 63% for stable disease (SD); 46% for minimal response (MR); 71% for partial response (PR); 66% for very good partial response (VGPR); and 25% for CR in MM patients. Among 73 responses categorized as CR, QIP-MS produced a positive result for the original clone in 55 (75.3%) cases. Concordance rates in WM patients were 71% for PD%; 30% for SD; 38% for MR; and 74% for PR; no VGPR or CR were reported by either method. Conclusions: In this study, QIP-MS demonstrated the potential for same or superior diagnostic sensitivity compared to SPE, high concordance with IFE for the M protein isotype and good quantitative agreement with SPE measurements of the M proteins. It reported higher IgM values compared to SPE, likely due to reliance on turbidimetric immunoglobulin measurement for quantitations. Diagnostic specificity was impacted by the identification of minor M proteins, not detectable by SPE, and whose clinical significance requires further investigation. QIP-MS demonstrated “moderate” to “fair” agreement for response assignment in MM and WM, respectively, mostly due to the detection of residual M proteins in a significant proportion of patients in CR, in line with its enhanced analytical sensitivity. These data support the use of QIP-MS as an aid in the diagnosis and monitoring of MGs.

Lymphoplasmacytic Lymphoma: An Atypical Presentation with IgG Monoclonal Gammopathy

Introduction Lymphocytic lymphoma (LPL) is a rare type of low-grade mature B-cell non-Hodgkin lymphoma, characterized by a monoclonal population of B lymphocytes, lymphoplasmacytic cells, and plasma cells. In around 95% of LPL cases, the serum immunoglobulin M (IgM) paraprotein is increased, which is correlated to Waldenstrom's Macroglobulinemia (WM), a clinicopathological disease. Only around 5% of LPL cases are associated with the serum paraproteins immunoglobulin G (IgG) or immunoglobulin A (IgA), or light chains alone, or are not linked to a paraprotein. Non-IgM LPLs have a wide range of clinical and pathological features, and MYD88 L265P mutations can occur, though at a lower frequency than WM. Hence, MYD88 testing is advised for prospective therapeutic purposes. Case Presentation A 69-year-old male was referred to a hematologist for uncontrolled epistaxis and periorbital edema. On initial workup, he had high total protein, elevated globulin, hypoalbuminemia, anemia, and proteinuria. Further investigation revealed a high IgG level with low IgM, IgA, and complement levels. Serum Protein Electrophoresis (SPEP): Increased total protein, decreased alpha two and beta globulins with a large monoclonal protein peak migrating in the gamma region, which accounts for 4.77 g/dl of the total 5.38g/dl gamma. Elevated Kappa Quantitative Free Light Chains of 355.39 (3.30 - 19.40mg/L), Decreased Lambda Quantitative Free Light Chains of 1.51 (5.71 - 26.30mg/L), Elevated Kappa Lambda Free Light Chains Ratio of 235.36 (0.26 - 1.65). Serum ImmunoFixation Electrophoresis demonstrated IgG-type kappa monoclonal protein with an additional faint band in IgG kappa. X-Ray skeletal survey showed a possible small lytic area in the inferior aspect of the C2 vertebral body, prompting him to have a cervical spine MRI which revealed no lytic lesions but an 18 mm vertebral body hemangioma inside T2. Molecular testing was positive for MYD88 Mutation c.794T&amp;gt;C (p. L265P) and negative for CXCR4 mutation. Plasma cell myeloma prognostic panel and chromosome analysis were normal. Flow cytometry of bone marrow aspirate showed a kappa light chain restricted plasma cell population (1.6% of total cells) with the following immunophenotype: positive for CD138, CD38, CD45, and negative for CD19, CD20, CD56, CD 117, and lambda light chains. The B-cell population showed kappa light chain restriction with the following immunophenotype: positive for CD19, CD20, and kappa light chains and negative for CD5, CD10, CD11c, CD23, and lambda light chains (Image 2). PET-CT of the whole body was negative for the extension of the disease. Transfusion with the two least incompatible PRBCs had little effect. However, plasmapheresis significantly improved his hemoglobin level by less than 7g/dl. A bone marrow biopsy revealed he had LPL with IgG Monoclonal Gammopathy (Image 1). He received one cycle of CyBorD (Cyclophosphamide, Bortezomib, Dexamethasone), followed by seven cycles of KCD (Carfilzomib, Cyclophosphamide, Dexamethasone) and Rituximab. The patient was diagnosed with low-grade B cell lymphoma with plasmocytic differentiation/lymphoplasmacytic lymphoma, with MYD88 mutation c.794T&amp;gt;C (p. L265P) positivity and CXCR4 mutation negativity. After plasmapheresis, the IgG level dropped to 1958. Follow-up SPEP revealed decreased alpha2 and beta globulins, decreased free lambda light chains, and increased K/L ratio. The patient was treated with Acalabrutinib, and his anemia, epistaxis, and coagulopathy resolved. Repeat PET-CT scan revealed no evidence of illness progression. Discussion LPL is not always linked with IgM monoclonal gammopathy; it can also be associated with IgG or IgA monoclonal gammopathy, light chains alone, or no monoclonal paraprotein. Non-IgM LPL has a high prevalence of extramedullary involvement, a lower rate of MYD88 mutation, and few hyper viscosity symptoms. The MYD88 mutation does not allow WM and Non-IgM LPL to be distinguished from other lymphoproliferative disorders with similar clinical and immunophenotypic features. The case described is unique as the patient has high levels of IgG (11,200) at presentation. In contrast to our patient, who has LPL with IgG Monoclonal gammopathy, approximately 95 percent of LPL patients have IgM Monoclonal gammopathy, which corresponds with WM. As a result, clinicians should be on the lookout for LPL that lacks an IgM Monoclonal Paraprotein.

Cost-effectiveness of systematic screening and treatment of transthyretin amyloid cardiomyopathy (ATTR-CM) in patients with heart failure with preserved ejection fraction (HFpEF) in United States

BackgroundTransthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed cause of heart failure in clinical practice. 99mTc-pyrophosphate scintigraphy (PYP-scan) improves the accuracy of ATTR-CM detection, enabling timely initiation of tafamidis, a drug that slows the progression of ATTR-CM and lowers the risk of adverse cardiac events. PYP-scans, serum free light-chain (FLC) test and immunofixation electrophoresis (IFE) are critical components of a systematic screening. We assessed the cost-effectiveness of universal systematic screening (USS) compared to standard-of-care (SoC) selected clinical referrals for the systematic screening in patients aged 60 years or older with heart failure with preserved ejection fraction (HFpEF) and ventricular wall thickness of at least 12 mm. MethodsTwo screening strategies, USS versus SoC screening for ATTR-CM were compared in a model-based assessment. Treatment decisions were based upon the accuracy of each screening strategy, which was followed by Markov state transitions across New York Heart Association (NYHA) functional classes and death. Model inputs were identified from a literature review. We calculated lifetime cost in 2022 US dollars and quality adjusted life-years (QALYs) of each strategy. The primary outcome was the incremental cost-effectiveness ratio (ICER). ResultsThe USS was associated with a significant increase in lifetime costs ($124,380 vs. $70,412) and modest improvement in QALYs (4.42 QALYs vs 4.36 QALYs). The ICER for the USS was $919,509 per QALY gained. ICER was sensitive to the age at the time of ATTR-CM diagnosis, true prevalence rate of ATTR-CM, and daily cost of tafamidis. ConclusionsOwing to the high cost of treatment with tafamidis, USS along with PYP scan for ATTR-CM in older HFpEF patients with ventricular wall thickening is unlikely to become a cost-effective strategy at a liberal WTP threshold.

Rare primary pulmonary mucosa-associated lymphoid tissue lymphoma misdiagnosed with tuberculosis: A case report.

Primary pulmonary mucosa-associated lymphoid tissue lymphoma (MALToma) is a rare subtype of non-Hodgkin lymphoma with a relatively low incidence rate clinically. Atypical clinical symptoms and nonspecific chest computed tomography features of the disease make it difficult to determine and treatment is delayed. We discuss the diagnosis and treatment of a patient with primary pulmonary MALToma to raise clinicians' awareness of this condition. A 66-year-old male patient with a medical history of tuberculosis has been experiencing progressive exacerbation of respiratory symptoms and nonresponsive treatment without an unclear diagnosis for 5 years. He was transferred to our hospital because a nonspecific soft tissue mass in the right upper lobe of the lung was found on his chest computed tomography. Laboratory results with serum immunofixation electrophoresis showed polyclonal immunoglobulin (Ig) G, IgM, IgA, and λ-light chain on admission. Pathological examination and immunohistochemical staining of lung biopsy revealed a definitive diagnosis of pulmonary MALToma with stage IV. The patient received immunotherapy with anti-CD20 monoclonal antibody (rituximab), and showed significant clinical improvement at the 6-month follow-up. Diagnosis of primary pulmonary MALToma mainly relies on histopathological examination, and comprehensive laboratory examinations are also necessary. Clinicians should combine laboratory tests (such as immunofixation electrophoresis in our case) to assist in medical diagnosis in cases of atypical clinical manifestations and imaging characteristics. Immunotherapy appears to be the main treatment protocol for advanced patients.

Complete blood and urine paraprotein tests as response assessments in multiple myeloma patients treated with bortezomib, cyclophosphamide, and dexamethasone.

This study assessed the effect of standardized efficacy markers on prognosis in patients with newly diagnosed multiple myeloma (MM) during the induction phase of treatment with bortezomib, cyclophosphamide, and dexamethasone (BCD). We retrospectively analyzed clinical data in 197 newly diagnosed MM patients treated with BCD as front-line regimen at Peking Union Medical College Hospital from January 1, 2013 to December 31, 2018. There were 107 patients with International Staging System (ISS) III and 51 with paraprotein of light chain. Of these, 77 completed nine cycles of the BCD regimen. As the number of treatment cycles increased, the proportions of serum and urine immunofixation electrophoresis (IFE) tests elevated from 40.39% to 62.22% and 16.75% to 37.78%, respectively. More than 90% of intact immunoglobulin chain MM patients were evaluated for blood M protein per cycle, but that of urinary M protein was less than 60%. The detection rate of urinary M protein in light chain MM was more than 70% per cycle. Patients with a very good partial response (VGPR) had longer progression-free survival (PFS) than those with uncertain VGPR (32 vs. 26 months, p = 0.0336). Of the 141 patients who completed at least four cycles without undergoing autologous hematopoietic stem cell transplantation, those who were regularly assessed at every other cycle showed more favorable PFS than those who visited irregularly (27 vs. 22 months, p = 0.059). Urinary M protein detection rate is significantly lower than that in serum, leading to an overestimation of efficacy, premature reduction of treatment intensity, and shortened PFS. Precise response assessments are critical to treatment decisions and clinical diagnoses.

First case report of PLA2R-related monotypic (IgG-κ positive) membranous nephropathy concurrent with leukocyte chemotactic factor 2 amyloidosis

BackgroundMembranous nephropathy (MN) is a major pattern of nephrotic syndrome (NS) in adults. Some MN have secondary causes and some may be accompanied with other glomerular diseases. MN patients coexisting with amyloidosis are very rare, and mostly was polytypic MN. Herein, we describe the first report which identifying monotype PLA2R-MN (κ light chain) concurrent with leukocyte chemotactic factor 2 amyloidosis (ALECT2). This rare case highlights the importance of renal pathology for diagnosis.Case presentationWe describe a case of a 60-year-old male patient with persistent proteinuria and low serum albumin for nine months. No monoclonal component was revealed by serum and urine immunofixation electrophoresis but serum PLA2R antibody was positive. The patient was empirically treated with Leflunomide and Losartan, but edema was not improved. The diagnosis of renal pathology is PLA2R-related monotypic (IgG-κ positive) MN concurrent with ALECT2. Methylprednisolone, cyclosporine A and anticoagulant (rivaroxaban) were prescribed resulting in a complete remission of NS.ConclusionsMN patients concurrent with ALECT2 presented massive proteinuria or NS. When nephrotic range proteinuria is present in ALECT2, it is important to consider that it may be due to a concomitant underlying nephropathy especially MN and treated according to MN will get good therapeutic effect.

Multiple Myeloma-Associated Leukocytoclastic Vasculitis Mimicking Autoimmune Vasculitis.

A 52-year-old man was admitted because of complaints of swelling and skin rashes on the extremities, fever, and arthralgia. Physical examination revealed bilateral ankle and wrist joint tenderness and livedo racemosa and purpura on the lower extremities (Figure, A). Cutaneous lesion biopsy showed leukocytoclastic vasculitis (Figure, B). Laboratory testing revealed a hemoglobin level of 5.6 g/dL, mildly decreased glomerular filtration rate, and an immunoglobulin G level of 3,936 mg/dL. Serum and urine immunofixation electrophoresis showed monoclonal kappa light chains. Bone marrow biopsy revealed proliferation of monoclonal plasma cells (Figure, C). Finally, the patient was diagnosed with leukocytoclastic vasculitis as the initial presentation of multiple myeloma. Cutaneous symptoms resolved within 6 weeks following treatment with daratumumab, lenalidomide, and dexamethasone (Figure, D). Although leukocytoclastic vasculitis is commonly associated with immune-mediated systemic vasculitis, cutaneous leukocytoclastic vasculitis may be observed in case of malignancy. Monoclonal gammopathies should be considered in cases of leukocytoclastic vasculitis associated with renal and blood disorders.Differential diagnosis: immunoglobulin A vasculitis, microscopic polyarteritis, granulomatosis with polyangiitis, and eosinophilic granulomatosis with polyangiitis.

Identifying therapeutic monoclonal antibodies using target protein collision electrophoresis reflex assay to separate the wheat from the chaff

Monoclonal gammopathies are characterized by the presence of monoclonal immunoglobulins, also known as M-proteins. Therapeutic monoclonal antibodies (t-mAbs) can interfere in laboratory assays used to monitor the state of disease, such as serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE). To establish a correct interpretation of IFE, Target protein-Collision Immunofixation Electrophoresis Reflex Assay (T-CIERA) was developed to identify t-mAbs in IFE. Here we demonstrate that T-CIERA is applicable to a wide variety of t-mAbs for which the target protein is commercially available. Moreover, the shift observed was characteristic for each t-mAb, and T-CIERA enabled the identification of multiple t-mAbs sharing a common target protein. Additionally, the lower limit of detection (LLOD) was determined objectively, and T-CIERA demonstrated an adequate LLOD for all tested t-mAbs. Furthermore, T-CIERA was also successfully applied to serum samples obtained from patients receiving daratumumab, isatuximab, elotuzumab, and durvalumab treatment. In conclusion, T-CIERA is a suitable reflex assay for identifying a wide variety of t-mAbs, including those for which no commercial assay is available to deal with their interference. Moreover, CD38-CIERA could serve as an alternative or complementary test to the commercially available Hydrashift assay kits. T-CIERA would enable laboratories without mass spectrometry equipment and expertise in this area to distinguish between drug and disease to improve clinical response monitoring and diagnosis of monoclonal gammopathies.