Detecting M-Protein via Mass Spectrometry and Affinity Beads: Enrichment With Mixed Kappa-Lambda Beads Enables Prompt Application in Clinical Laboratories.

Background: Detecting monoclonal protein (M-protein), a hallmark of plasma cell disorders, traditionally relies on methods such as protein electrophoresis, immune-electrophoresis, and immunofixation electrophoresis (IFE). Mass spectrometry (MS)-based methods, such as matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and electrospray ionization-quadrupole time-of-flight (ESI-qTOF) MS, have emerged as sensitive methods. We explored the M-protein-detection efficacies of different MS techniques. Methods: To isolate immunoglobulin and light chain proteins, six types of beads (IgG, IgA, IgM, kappa, lambda, and mixed kappa and lambda) were used to prepare samples along with CaptureSelect nanobody affinity beads (NBs). After purification, both MALDI-TOF MS and liquid chromatography coupled with Synapt G2 ESI-qTOF high-resolution MS analysis were performed. We purified 25 normal and 25 abnormal IFE samples using NBs and MALDI-TOF MS (NB-MALDI-TOF). Results: Abnormal samples showed monoclonal peaks, whereas normal samples showed polyclonal peaks. The IgG and mixed kappa and lambda beads showed monoclonal peaks following the use of daratumumab (an IgG/kappa type of monoclonal antibody) with both MALDI-TOF and ESI-qTOF MS analysis. The limits of detection for MALDI-TOF MS and ESI-qTOF MS were established as 0.1 g/dL and 0.025 g/dL, respectively. NB-MALDI-TOF and IFE exhibited comparable sensitivity and specificity (92% and 92%, respectively). Conclusions: NBs for M-protein detection, particularly with mixed kappa-lambda beads, identified monoclonal peaks with both MALDI-TOF and ESI-qTOF analyses. Qualitative analysis using MALDI-TOF yielded results comparable with that of IFE. NB-MALDI-TOF might be used as an alternative method to replace conventional tests (such as IFE) to detect M-protein with high sensitivity.

Elevated polyclonal IgG4 mimicking a monoclonal gammopathy in IgG4-related disease-a case-based review.

IgG4-related diseases (IgG-RDs) are a group of fibroinflammatory diseases that affect a variety of tissues, resulting in tumour-like effects and/or organ dysfunction. Monoclonal gammopathies (MGPs) are a group of disorders characterized by clonal proliferation of plasma cells or lymphoid cells resulting in the secretion of a monoclonal immunoglobulin. Cases of MGPs in IgG4-RDs coexisting with plasma cell dyscrasias and lymphoid neoplasms have been reported over the past few years. Therefore, the results of examinations of M protein in IgG4-RD patients should be interpreted with caution. Herein, we report the case of a 58-year-old male with a history of type 2 diabetes who presented with submandibular masses, anosmia, swollen lymph nodes, proteinuria, and renal impairment. Laboratory tests revealed hyperglobulinemia and elevated levels of IgG4 (124 g/L) and serum-free light chains (sFLCs). Serum protein electrophoresis (SPEP) revealed an M spike of 5.6 g/dL, and immunofixation electrophoresis (IPE) revealed biclonal IgG-κ and IgG-λ. The patient underwent bone marrow, lymph node, and kidney biopsy, which ruled out plasma cell disorders and lymphoma. He was finally diagnosed with an IgG4-RD comorbid with diabetic nephropathy. The findings in this case highlight that significant activation of B cells in IgG4-RD patients, especially those with multiorgan involvement can lead to significant hyperglobulinemia and high sFLC and IgG4 levels, which are more pronounced in the setting of renal impairment. Relatively high concentrations of polyclonal IgG4 can give rise to a focal band bridging the ß and γ fractions, which may mimic the appearance of a monoclonal band on SPEP and monoclonal gammaglobulinemia in IFE. The patient experienced considerable improvement in his symptoms after rituximab combined with glucocorticoid therapy, and a monoclonal immunoglobulin was not detected.

Reduction rate of monoclonal protein as a useful prognostic factor in standard-risk group of newly diagnosed multiple myeloma.

BACKGROUND: Multiple myeloma (MM) is a common hematologic malignancy that originates from a malignant clone of plasma cells. Solitary plasmacytoma, history of diabetes, and platelet count are considered as prognostic factors for MM. But some patients are still associated with much worse outcomes without any prognostic predictors. This study aimed to observe the reduction rate of monoclonal protein (M protein) after the first and fourth chemotherapy cycles, which is considered as a new prognostic factor for progression-free survival (PFS) in standard-risk group of newly diagnosed MM patients. AIM: To investigate the reduction rate of M protein after first and fourth cycle chemotherapy as a useful prognostic factor. METHODS: A total of 316 patients diagnosed with MM for the first time between 2010 and 2019 at the Lishui Municipal Central Hospital were included. All patients were diagnosed according to the National Comprehensive Cancer Network (NCCN) 2020.V1 diagnostic criteria. The risk assessment was performed by the Mayo Stratification for Macroglobulinemia and Risk-Adapted Therapy guidelines. After diagnosis, 164 patients were evaluated and underwent treatment with four to eight courses of continuous induction chemotherapy. The patients with no response after induction treatment were administered additional therapy following the NCCN 2020.V1 criteria. The following baseline data from the patients were collected: Gender, age at diagnosis, Durie-Salmon stage, glutamic-pyruvic transaminase, glutamic-oxaloacetic transaminase, catabolite activator protein, albumin/globulin ratio, lactate dehydrogenase, translocation (t)(6;14), t(11;14), maintenance regimen, total cholesterol (TC), triglyceride, and phosphorous. All baseline data and the reduction rate of M protein after each chemotherapy cycle from the first to fourth were assessed by univariate analysis. The factors influencing the overall survival and PFS were then assessed by multivariate analysis. We found the first cycle (C1) reduction rate and the fourth cycle (C4) reduction rate as predictors of PFS. Then, PFS was compared between patients with a C1 reduction rate of M protein of ≥ 25% vs < 25% and ≥ 50% vs < 50%, and between patients with a C4 reduction rate of ≥ 25% vs < 25%, ≥ 50% vs < 50%, and ≥ 75% vs < 75%. RESULTS: Multivariate analysis revealed age [hazard ratio (HR): 1.059, 95% confidence interval (95%CI): 1.033-1.085, P ≤ 0.001], International Staging System stage (HR: 2.136, 95%CI: 1.500-3.041, P ≤ 0.001), autotransplantion (HR: 0.201, 95%CI: 0.069-0.583, P = 0.019), TC (HR: 0.689, 95%CI: 0.533-0.891, P = 0.019), C1 reduction rate (HR: 0474, 95%CI: 0.293-0.767, P = 0.019), and C4 reduction rate (HR: 0.254, 95%CI: 0.139-0.463, P = 0.019) as predictors of PFS. The Kaplan-Meier survival analysis and the log-rank tests revealed that a higher reduction rate of M protein after first cycle (≥ 50%) and fourth cycle (≥ 75%) chemotherapy was associated with a longer PFS than the lower one. CONCLUSION: Higher reduction rates of M protein after the first and fourth chemotherapy cycles can act as advantageous prognostic factors for PFS in standard-risk group of MM patients during initial diagnosis.

Case Report: Effects of multiple myeloma therapy on essential thrombocythemia and vice versa: a case of synchronous dual hematological malignancy.

Background: Dual hematological malignancies, asynchronous or synchronous, are underrecognized entities and are usually suspected when clinical, hematological, or biochemical features cannot be explained by the primary malignancy alone. We present a case of synchronous dual hematological malignancies (SDHMs), where the patient was diagnosed with symptomatic multiple myeloma (MM) and essential thrombocythemia (ET), when excessive thrombocytosis occurred following initiation of MPV (melphalan-prednisone-bortezomib) antimyeloma therapy. Case description: An 86-year-old woman presented to the emergency in May 2016 with confusion, hypercalcemia, and acute kidney injury. She was diagnosed with free light chain (FLC) lambda and Immunoglobulin G (IgG) lambda MM and started MPV (standard of care at that time) treatment with darbopoietin support. At diagnosis, she had normal platelet count since the ET was likely masked by bone marrow suppression due to active MM. After she reached stringent complete remission with no MP detected on serum protein electrophoresis or immunofixation, we noticed that her platelet counts increased to 1,518,000 × 109/L. She was tested positive for mutation in exon 9 of calreticulin (CALR). We concluded that she had concomitant CALR-positive ET. After bone marrow recovery from MM, the ET became clinically apparent. We started hydroxyurea for ET. Treatment for MM with MPV did not affect the course of ET. Presence of concomitant ET did not decrease the efficacy of sequential antimyeloma therapies in our elderly and frail patient. Conclusion: The possible mechanism underlying the occurrence of SDHMs is unclear but is likely due to stem cell differentiation defects. SDHMs can be challenging to treat and warrant several considerations. In the absence of clear guidelines on how to manage SDHMs, management decisions depend on several factors including disease aggressiveness, age, frailty, and comorbidities.

Detection of serum M-protein in acetonitrile precipitates by MALDI-TOF mass spectrometry: A novel, low-cost methodology.

BACKGROUND: Several studies have demonstrated the analytical sensitivity of MALDI-TOF mass spectrometry (MALDI-TOF MS) by immunoenrichment for M-protein analysis. We report the results of a novel, low-cost, reagent-based extraction process using acetonitrile (ACN) precipitation to enrich for κ and λ light chains which can be analysed by MALDI-TOF MS. METHODS: Institutional Ethics committee approval was obtained. Serum samples from patients with monoclonal gammopathy of undetermined significance (MGUS), multiple myeloma (MM), plasmacytoma, AL amyloidosis and Waldenström macroglobulinemia (WM) underwent ACN precipitation. The images obtained were overlaid on apparently healthy donor serum samples to confirm the presence of M-protein. A sample was considered positive for M-protein if there was a sharp or broad peak within the κ or λ mass/charge (m/z) range: m/z- [M + 2H]2+: 11,550-12,300 Da and λ m/z- [M + 2H]2+: 11,100-11,500 Da. Images were acquired at a m/z range of 10,000-29,000 Da. Corresponding serum protein electrophoresis (SPEP), serum immunofixation electrophoresis (IFE) and serum free light chain (sFLC) assay by nephelometry were performed for all the samples. RESULTS: Two-hundred-and-two serum samples were included in the study: MM- 184 (91%); AL amyloidosis- 2 (1%); plasmacytoma- 8 (4%); MGUS- 6 (3%) and WM- 2 (1%). All the SPEP positive samples were identified by MALDI-TOF MS. Out of 179 samples positive for M-protein by IFE, MALDI-TOF MS was positive in 176 samples (98%). Compared to IFE, the sensitivity and specificity of M-protein identification by MALDI-TOF MS were 98.3% and 52.2%, respectively. CONCLUSIONS: This study demonstrates the feasibility of qualitatively identifying M-protein without the need for antibody-based immunoenrichment, making the technique cost-effective.

Encephalitis associated with a monoclonal protein band present in blood, urine and cerebrospinal fluid.

Introduction: Monoclonal protein bands are present mainly in blood and secondary in urine representing specific antibody produced in excess by abnormal lymphocytes or plasma cells.We describe a case of a patient with acute encephalitis associated with an unexpected finding of a monoclonal protein band present in blood, urine and in cerebrospinal fluid (CSF). Case presentation: This 50-year-old woman with no significant past medical history, with the exception of unintentional weight loss exceeding 5 kg over the last 3 months, presented to the emergency department with seizures and altered mental status, after 3 days of vomiting and headaches. Magnetic Resonance Imaging showed lesions suspicious for infectious encephalitis/meningitis and for ischemia possibly related to central nervous system (CNS) autoimmune vasculopathy/vasculitis. The patient died the following day after losing brainstem reflexes. Testing for the previously mentioned etiologies returned negative with the exception of high protein concentration and increased immunoglobulin gamma (IgG) concentration in the CSF. Protein electrophoresis, ordered in error, showed a well-defined IgG with lambda light chain monoclonal protein band running in similar positions in serum, urine and in CSF. Due to SARS-CoV-2 PCR positivity no autopsy was performed. Conclusion: The presence of this monoclonal protein band produced in the CNS suggests the diagnosis of CNS myeloma. The accelerated course in this case could be the result of the CNS myeloma or lymphoma responding to SARS-CoV-2 infection. Testing for monoclonal protein bands in CSF, in patients with pertinent clinical presentation would boost the awareness of this these diseases improving patient care.

The clinical value of monoclonal protein in ANCA-associated vasculitis with renal involvement.

PURPOSE: The value of monoclonal protein (M-protein) in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients with renal involvement has not been investigated. METHODS: We analyzed AAV patients with renal involvement from 2013 to 2019 in our center. Patients with immunofixation electrophoresis were divided into M-protein positive group and M-protein negative group. The clinicopathological features and outcomes of the two groups were compared. RESULTS: Ninety-one AAV patients with renal involvement were enrolled for analysis, and 16 patients (17.6%) had a positive test for M-protein. Compared with M-protein negative patients, M-protein positive patients had lower hemoglobin (77.6 vs 88.4 g/L, p = 0.016), mean corpuscular hemoglobin concentration (313 vs 323 g/L, p = 0.002),serum albumin (29.4 vs 32.5 g/L, p = 0.026) and complement 3 (C3) (0.66 vs 0.81 g/L, p = 0.047), while higher platelets (252 vs 201 109/L, p = 0.048) and incidence of pulmonary infection (62.5% vs 33.3%, p = 0.029). However, renal pathological features between the two groups had no significant difference. In addition, during a median follow-up of 33 months, Kaplan-Meier survival analysis showed that, compared with M-protein negative patients, M-protein positive patients had a higher risk of all-cause mortality (log-rank test, p = 0.028), especially for patients who were not dialysis-dependent at the time of admission (log-rank test, p = 0.012). CONCLUSION: Our results indicate that M-protein is associated with different clinicopathological features and increased all-cause mortality in AAV patients with renal involvement. Testing M-protein and rigorous diagnosing of the significance of the presence of M-protein may be helpful for assessing the survival of AAV patients with renal involvement.

Epidemiology of monoclonal gammopathy in Morocco - A hospital-based study.

BACKGROUND: Monoclonal gammopathies are a group of disorders associated with clonal proliferation of plasma cells that produces a monoclonal protein. AIMS: The main objective of this study was to describe the epidemiological and immunochemical characteristics of monoclonal gammopathies diagnosed during 19 years in a Moroccan teaching hospital. MATERIALS AND RESULTS: This retrospective study enrolled 443 Moroccan patients with monoclonal gammopathy, patients meeting the inclusion and exclusion criteria in at the biochemistry department of Military Hospital in Rabat, the capital of Morocco, from January 2000 to August 2019. Of the 443 enrolled patients, 320 (72.23%) were men and 123 (27.77%) were women. All patients were of Caucasian origin, from 12 Moroccan regions. The patient's samples were collected and subjected to serum protein electrophoresis and serum immunofixation electrophoresis to further characterize the monoclonal protein. The mean ± SD age of the 443 participants was 62.24 ± 13.14 years. Reasons for being admitted to the hospital were as follows, bone pain (41.60%), renal failure (19.08%), alteration of the general condition (12.21%), and anemia (10.69). Plasma cell proliferative disorders in our study were as follows, multiple myeloma (MM) (45.65%), Monoclonal gammopathies of undetermined significance (MGUS) (39.05%), Waldenstrom's macroglobulinemia (5.58%), Lymphoma (2.27% + 1.2%), Chronic Lymphocytic Leukemia (2.48%), Plasma cell leukemia (1.86%), Plasmacytoma (0.62%), POEMS syndrome (0.41%), and Amyloidosis (0.84%). The most frequent isotypes in MM were the IgGκ (62) 36.5%, IgGλ (52) 30.6%, IgAκ (27) 15.9%, and the IgAλ (19) 11.2%. It is also worth noting that Free light chain MM represents 20% of all cases of MM. CONCLUSIONS: We found that monoclonal gammopathies are age-related and affects men more than women, also the results of this study point to the delayed diagnosis of monoclonal gammopathies, since most of our patients were diagnosed at the MM stage. The most frequent isotypes were the IgGκ and IgGλ in MM and MGUS, in Waldenström macroglobulinemia were IgMκ and IgMλ and the oligoclonal profile represented only 3.70%.

Monoclonal gammopathy of renal significance: Multidisciplinary approach to diagnosis and treatment.

Monoclonal gammopathy of renal significance (MGRS) is a hemato-nephrological term referring to a heterogeneous group of kidney disorders characterized by direct or indirect kidney injury caused by a monoclonal immunoglobulin (MIg) produced by a B cell or plasma cell clone that does not meet current hematologic criteria for therapy. MGRS-associated kidney diseases are diverse and can result in the development of end stage kidney disease (ESKD). The diagnosis is typically made by nephrologists through a kidney biopsy. Many distinct pathologies have been identified and they are classified based on the site or composition of the deposited Mig, or according to histological and ultrastructural findings. Therapy is directed towards the identified underlying clonal population and treatment decisions should be coordinated between hematologists and nephrologists in a multidisciplinary fashion, depend on the type of MGRS, the degree of kidney function impairment and the risk of progression to ESKD.

Unraveling the Possibilities of Monoclonal Protein Migration, Identification, and Characterization in SPEP on Capillary Zone Electrophoresis.

Serum protein electrophoresis (SPEP) is a method by which proteins present in serum are separated into different fractions based on their molecular weight and electric charge. Presence of M spike, composed of monoclonal protein, on electrophoretogram is a characteristic finding that can be seen in monoclonal gammopathies like multiple myeloma. M spike is most commonly seen in the gamma region however, the M-spike can be observed in fraction other than the Y fraction as well i.e. in the beta region and rarely alpha region. Here we have enumerated few cases where M protein has been seen in fractions other than the gamma region. Thus one needs to be cautious about the variable appearance of M-spike during interpretation of SPEP as some physiological proteins if elevated can also give rise to similar spike sometimes referred as pseudo monoclonal pattern.

Cardiovascular Morbidity in Monoclonal Gammopathy of Undetermined Significance: A Danish Nationwide Study.

Background: Monoclonal gammopathy of undetermined significance (MGUS) is associated with renal dysfunction, inflammation, and increased cardiovascular mortality, but the cardiovascular risks are not fully understood. Objectives: The authors explored the association of MGUS with a spectrum of cardiovascular diseases using the Danish nationwide databases. Methods: Between 1995 and 2018, patients 18 years and older with MGUS were age- and sex-matched (1:10) with control patients and followed prospectively until December 31, 2018, for the occurrence of cardiovascular diseases. Patients diagnosed with multiple myeloma, lymphoma, or amyloidosis were excluded. Multivariable adjusted hazard ratios (HRs) for cardiovascular outcomes were estimated using Cox proportional hazard regression. Results: Patients with MGUS (n = 8,189; mean age 69.8 ± 11.7 years; 51.2% male) had higher prevalence of cardiovascular risk factors at baseline, including hypertension (48.0% vs 38.5%) and type 2 diabetes (13.0% vs 9.3%), compared with control patients. Outcomes included an increased risk of heart failure (HR: 1.55; 95% CI: 1.41-1.69), acute myocardial infarction (HR: 1.22; 95% CI: 1.06-1.40), ischemic stroke (HR: 1.16; 95% CI: 1.03-1.30), atrial fibrillation (HR: 1.32; 95% CI: 1.23-1.42), aortic aneurysm (HR: 1.55; 95% CI: 1.28-1.89), aortic stenosis (HR: 1.60; 95% CI: 1.41-1.82), aortic regurgitation (HR: 1.67; 95% CI: 1.34-2.07), heart block (HR: 1.32; 95% CI: 1.08-1.61), peripheral artery disease (HR: 1.69; 95% CI: 1.47-1.95), cor pulmonale (HR: 2.06; 95% CI: 1.55-2.73), and venous thromboembolism (HR: 1.43; 95% CI: 1.24-1.65). A sensitivity analysis including only patients without certain comorbidities (type 2 diabetes, hypertension, acute myocardial infarction, and chronic kidney disease) yielded similar results. Conclusions: MGUS is associated with a broad spectrum of cardiovascular diseases, with greater relative risks observed for diseases previously associated with infiltrative and inflammatory disorders. Further studies are warranted to explore the underlying mechanisms.

Monoclonal Gammopathy-Related Kidney Diseases.

Monoclonal gammopathies occur secondary to a broad range of clonal B lymphocyte or plasma cell disorders, producing either whole or truncated monoclonal immunoglobulins. The kidneys are often affected by these monoclonal proteins, and, although not mutually exclusive, can involve the glomeruli, tubules, interstitium, and vasculature. The nephrotoxic potential of these monoclonal proteins is dependent on a variety of physicochemical characteristics that are responsible for the diverse clinicopathologic manifestations, including glomerular diseases with organized deposits, glomerular diseases with granular deposits, and other lesions, such as C3 glomerulopathy and thrombotic microangiopathy with unique pathophysiologic features. The diseases that involve primarily the tubulointerstitial and vascular compartments are light chain cast nephropathy, light chain proximal tubulopathy, crystal-storing histiocytosis, and crystalglobulin-induced nephropathy with distinct acute and chronic clinicopathologic features. The diagnosis of a monoclonal gammopathy-related kidney disease is established by identification of an underlying active or more commonly, low-grade hematologic malignancy, serologic evidence of a monoclonal gammopathy when detectable, and most importantly, monoclonal protein-induced pathologic lesions seen in a kidney biopsy, confirming the association with the monoclonal protein. Establishing a diagnosis may be challenging at times, particularly in the absence of an overt hematologic malignancy, with or without monoclonal gammopathy, such as proliferative glomerulonephritis with monoclonal immunoglobulin deposits. Overall, the treatment is directed against the underlying hematologic disorder and the potential source of the monoclonal protein.

Defects and countermeasures in laboratory diagnosis of rare IgE multiple myeloma.

BACKGROUND: IgE multiple myeloma (MM) is a rare subtype of MM that is easily misdiagnosed. We report a rare case of IgE-MM and investigate the application of the SLiM-CRAB criteria to screen for high-risk smoldering MM (SMM) patients, so as to summarize the causes and methods used to prevent missed diagnosis or misdiagnosis in IgE-MM. METHODS: The serum monoclonal protein (M-protein) classification and IgE quantification was performed and sent to several individual institutions. The results were collected and the causes of IgE detection defects were analyzed. RESULTS: Upon admission to our hospital, the patient's serum free kappa light chain was 1069.9 mg/L, free lambda light chain was 9.2 mg/L, and free kappa/lambda ratio was 115.9, which met the SLiM criteria, but without CRAB features. Immunofixation electrophoresis (IF) showed "M-like protein aggregation bands" in all lanes. After pretreatment with 1% ß-mercaptoethanol to depolymerize the aggregation of monoclonal protein, the "M-like protein aggregation bands disappeared. The other five institutions did not provide the correct typing results. The quantification of serum IgE was as high as 2.06 × 107 IU/mL, whereas 7 other testing institutions reported IgE levels ranging from 1.0 to 1100 IU/mL. CONCLUSION: High-risk biomarkers in SLiM criteria can achieve good therapeutic effects in rare IgE-MM patients. Serum immunofixation performed without antisera against IgE, insufficient identification of the lytic bands produced by high macromolecule aggregation in IF, and the absence of a prozone effect avoidance procedure during IgE quantitative detection are the primary causes of missed diagnosis or misdiagnosis in patients with IgE-MM.

Impact of Etiological Cytogenetic Abnormalities on the Depth of Immunoparesis and Survival in Newly Diagnosed Multiple Myeloma.

INTRODUCTION/BACKGROUND: Immunoparesis, or low polyclonal immunoglobulin levels, is commonly seen in multiple myeloma (MM), and is associated with poor clinical outcomes. MM can be divided into subgroups with distinct biology and outcomes based on etiologic cytogenetic abnormalities. These include hyperdiploidy and translocations of t(11;14), t(4;14), t(14;16), and t(14;20), with the latter 3 associated with high-risk disease. We hypothesized that the different etiologic cytogenetic abnormalities drive bone marrow microenvironmental changes, resulting in different degrees of immunoparesis, and subgroup-dependent effects on clinical outcomes. MATERIALS AND METHODS: We performed a retrospective review of 985 newly diagnosed patients enrolled in the Myeloma IX and XI trials. Immunoglobulin levels, survival outcomes, and infection rates were evaluated for each cytogenetic subgroup. RESULTS: A significant proportion of patients with high-risk t(4;14), t(14;16), or t(14;20) had suppressed polyclonal immunoglobulins compared to standard-risk patients with hyperdiploidy or t(11;14). The clinical impact of immunoparesis depended on the cytogenetic subgroup, with the degree of IgM suppression effecting progression-free and overall survival only in the hyperdiploid subgroup. There was no significant difference in infection rates amongst the etiologic subgroups. CONCLUSION: These findings demonstrate that the etiologic cytogenetic subgroup influences the degree and clinical impact of immunoparesis. This suggests that the underlying cytogenetic abnormality affects remodeling of the bone marrow plasma cell niche, resulting in suppressed normal plasma cell function, and low immunoglobulin levels.

[Monoclonal gammopathy of undetermined significance and evolution to myeloma: Experience in 153 patients]. / Gammapatía monoclonal de significado incierto y evolución a mieloma múltiple: Experiencia en 153 pacientes.

INTRODUCTION: Based on risk factors, the Mayo Clinic Multiple Myeloma Group (MCMMG) established a model of progression from monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM) at 20 years. It is also described that MGUS with a progressive increase of monoclonal protein (M-protein) and/or immunoparesis (IMP) may be more predisposed to progress to myeloma. Our objective was to make a review of MGUS, to see how those who presented IMP and/or progression of their M-protein, contrasting them with MGUS that presented intermediate/high and high risk according to MCMMG. METHODOLOGY AND MATERIALS: A review of the MGUS objectified during the realization of a serum proteinogram (SPEP) was carried out during 2010-2014, in our area. Serum immunoglobulins, serum immunofixation (IFs), and serum free light chain ratio (FLCr) were determined for all MGUS. RESULTS: Of the 153 MGUS that are followed up for 4 years, 6 progress to MM. Of these 6 MM, 5 progress from MGUS with intermediate/high risk taking into account the MCMMG. Of these 5, 3 have IMP or progression of their M-protein. 2 present IMP plus progression of their M-protein. The sixth MM evolves from a MGUS without any risk factor, but with progression of its M-protein plus IMP. CONCLUSIONS: IMP and/or M-protein progression are important risk factors to be taken into account in the MGUS, in the first years after diagnosis, due to their possible evolution to MM.

Evaluation of a Capillary Electrophoresis System for the Separation of Proteins.

BACKGROUND: Serum protein electrophoresis is one of the core investigations for screening for monoclonal proteins. Among the available capillary systems, the Helena V8 system has been evaluated in a limited number of studies. METHODS: In total, 310 sera samples were assessed on the Helena V8 system and compared with the Sebia Capillarys instrument. Abnormalities suggestive of monoclonal proteins were confirmed by immunofixation. Imprecision studies and reference intervals were determined. RESULTS: The imprecision of the Helena V8 was inferior or equal to 5.8%. The mean bias of Helena V8 vs Sebia Capillarys was about -0.9 g/L for albumin; -0.2 g/L for alpha-1; 1.1 g/L for alpha-2; -0.2 g/L for beta; 0.3 g/L for gamma; -0.5 g/L for monoclonal protein in beta; and 0.3 g/L for monoclonal protein in gamma. Among the 56 samples with monoclonal proteins confirmed by immunofixation, all were seen on both methods, with only 1 discordant result at a cutoff of 5.0 g/L. Reference intervals were statistically different between the 2 analyzers, except for the beta fraction. CONCLUSIONS: Our evaluation confirms the good analytical performance of the Helena V8 analyzer as a suitable alternative to the Sebia Capillarys instrument.