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1.
Ann Hematol ; 103(4): 1261-1271, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38114824

RESUMO

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.


Assuntos
Linfoma Difuso de Grandes Células B , Humanos , Prognóstico , Linfoma Difuso de Grandes Células B/patologia , Análise Multivariada , Estudos Retrospectivos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Eletroforese
2.
Br J Haematol ; 193(2): 299-306, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33200406

RESUMO

The presence of a serum monoclonal component has been associated with poor outcomes in some lymphomas. However, data in follicular lymphoma (FL) are scarce. We studied 311 FL patients diagnosed at a single institution, for whom information on serum immunofixation electrophoresis (sIFE) at diagnosis was available. Baseline characteristics and outcomes were compared between patients with a positive (+sIFE) and a negative sIFE (-sIFE). sIFE was positive in 82 patients (26%). Baseline features were comparable between both groups, except for an older age and higher proportion of elevated ß2 -microglobulin levels in the +sIFE group. With a median follow-up of 4.6 years, a +sIFE was associated with a higher risk of early relapse (POD24, 27% vs. 15%, P = 0·02), shorter progression-free survival (PFS; 42% vs. 52% at 5 years, P = 0·008), and shorter overall survival (OS; 59% vs. 77% at 10 years, P = 0·046). In patients >60 years, a +sIFE was an independent predictor of OS [hazard ratio (HR) = 2·4, 95% confidence interval (CI): 1·2-5·0; P = 0·02]. Approximately one quarter of patients with FL has a +sIFE at diagnosis, which is a predictor of poor outcome. These findings encourage further investigation of its relationship with B-cell biology and the tumour microenvironment.


Assuntos
Eletroforese das Proteínas Sanguíneas/métodos , Linfoma Folicular/metabolismo , Gamopatia Monoclonal de Significância Indeterminada/sangue , Microglobulina beta-2/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ciclofosfamida , Doxorrubicina , Feminino , Seguimentos , Humanos , Linfoma Folicular/tratamento farmacológico , Linfoma Folicular/mortalidade , Linfoma Folicular/patologia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores/métodos , Prednisona , Prognóstico , Intervalo Livre de Progressão , Rituximab , Microambiente Tumoral , Vincristina , Conduta Expectante
3.
Indian J Clin Biochem ; 34(1): 76-81, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30728676

RESUMO

Demonstration of monoclonal immunoglobulin molecule in serum forms the mainstay in the diagnosis of monoclonal gammopathies. The major tests that help in this regard are serum protein electrophoresis (SPEP), serum immunofixation electrophoresis (sIFE) and serum free light chain assay (sFLC). Our objectives were to study the accuracy of sFLC and sIFE in the diagnosis of monoclonal gammopathies and also to study the role of combination of SPEP + sIFE + sFLC in the diagnosis of the same. 46 patients who attended the hemato-oncology clinic with signs and symptoms suggestive of monoclonal gammopathy were enrolled in this study. SPEP, sIFE, sFLC and pre-treatment serum beta-2 microglobulin levels were analysed among the study population. Both SPEP and sIFE were performed in the Interlab Genios fully automated machine. Serum beta-2 microglobulin and sFLC were estimated by immunoturbidimetry in Beckman Coulter AU 2700 analyzer. The accuracy of sIFE came to be 80% with respect to sFLC assay. Sensitivity, specificity, positive and negative predictive value of sIFE with respect to sFLC were 81.3, 78.6, 89.7 and 64.7% respectively. It was observed that a combination panel of SPEP + sIFE + sFLC could detect all the cases of myeloma included in this study. Further testing in large samples is required for generalising the findings of this study. The pre-treatment beta-2 microglobulin levels were significantly higher in the group which was positive for myeloma. A combination panel of SPEP + sIFE + sFLC prove to be more useful than individual tests for the detection of myeloma.

6.
Pathol Biol (Paris) ; 63(4-5): 215-21, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26319969

RESUMO

BACKGROUND: Serum protein electrophoresis (SPE) and immunofixation electrophoresis (IFE) are used for diagnosis and follow-up of patients with intact immunoglobulin multiple myeloma. However, the numerous limitations of these methods led to the development of a nephelometric immunoassay (Hevylite™) for the specific measurement of serum IgGκ, IgGλ, IgAκ and IgAλ concentrations. METHODS: In this study, we evaluated the correlation between this assay and SPE and IFE in 114 sera of 15 patients (12 IgG and 3 IgA patients) and its impact on the clinical care of patients, especially for diagnosis, for the evaluation of residual disease and for early detection of relapse. RESULTS: At inclusion and during follow-up, we found a good correlation between monoclonal immunoglobulin concentrations and SPE (R(2)=0.902 for IgA and R(2)=0.915 for IgG) and nephelometric quantification (R(2)=0.948 for IgA and R(2)=0.920 for IgG) for the evaluation of monoclonal and polyclonal immunoglobulins. Our results illustrate that the Hevylite™ test is less sensitive than the IFE for detection of residual disease: 5 patients who obtained very good partial response or complete response had normalization of the Hevylite™ ratio while IFE was still positive. A relapse had been detectable with the Hevylite™ ratio 1 to 2 months earlier than with SPE and IFE in 3 patients out of 15, but no recommendations for treating patients with only slight biological relapse are available. CONCLUSION: Our results demonstrate that heavy/light chain specific immunoglobulin ratios provides no additional information than serum proteins electrophoresis and immunofixation for the diagnosis and the follow-up of intact immunoglobulin multiple myeloma patients. We also studied the correlation between the concentration of total immunoglobulin measured by Hevylite™ (sum of Ig'κ + Ig'λ) and nephelometric measurement of total IgG or IgA. For this correlation analysis, all 114 sera were analyzed. The correlation coefficient was R(2) = 0.948 for IgA and R(2) = 0.920 for IgG.


Assuntos
Eletroforese das Proteínas Sanguíneas , Imunoeletroforese , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Cadeias Pesadas de Imunoglobulinas/sangue , Cadeias Leves de Imunoglobulina/sangue , Mieloma Múltiplo/sangue , Proteínas do Mieloma/análise , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/tratamento farmacológico , Neoplasia Residual , Estudos Prospectivos , Resultado do Tratamento
7.
Hematology ; 29(1): 2352686, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38819332

RESUMO

BACKGROUND: Data on the prevalence of monoclonal gammopathy of undetermined significance (MGUS) in China are very limited. Our aim was to determine the prevalence and clinical characteristics of MGUS in a large Chinese population. METHODS: This study included 49,220 healthy people who received serum immunofixation electrophoresis (sIFE) and serum protein electrophoresis (SPE) tests. Serum free light chain ratio, immunoglobulin quantification, and other clinically correlates of MGUS were performed for all patients with M-protein. RESULTS: A total of 576 MGUS patients were identified by sIFE, with a median age of 58 years and an overall prevalence of 1.17% (95% CI, 1.08-1.27). Among those aged 50 years and older, the prevalence of MGUS was 2.26% (95% CI, 2.04-2.50). The prevalence of MGUS was significantly higher in males than in females (P < 0.05). The median concentration of M-protein was 3.1 g/L, ranging from 0.5 g/L to 25.1 g/L. The M-protein type was IgG in 55.4% of MGUS patients, followed by IgA (31.1%), IgM (9.5%), IgD (0.5%), biclonal (2.3%), and light chain (1.2%). Abnormalities in SPE, FLC ratios, and immunoglobulin levels were observed in 78.3%, 31.1%, and 38.4% of MGUS patients, respectively. CONCLUSIONS: The prevalence of MGUS is substantially lower in southern China than in whites and blacks.


Assuntos
Gamopatia Monoclonal de Significância Indeterminada , Humanos , Masculino , Gamopatia Monoclonal de Significância Indeterminada/epidemiologia , Gamopatia Monoclonal de Significância Indeterminada/sangue , China/epidemiologia , Feminino , Pessoa de Meia-Idade , Prevalência , Idoso , Adulto , Idoso de 80 Anos ou mais , Adolescente , Adulto Jovem
8.
Indian J Nephrol ; 34(1): 59-63, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38645913

RESUMO

Monoclonal gammopathy of renal significance (MGRS) has gained importance because identifying the monoclonal deposit and addressing it, rather than treating renal dysfunction as the primary pathology, has salvaged the patients from progressing into end-stage renal disease. Since it affects elderly population, there could be a propensity to misdiagnose them with cardiorenal syndrome. We present four patients of MGRS diagnosed from our center. They presented with proteinuria or unexplained renal dysfunction. Three of the patients were diagnosed to have amyloidosis, of which two had lambda-type and one had kappa amyloidosis. The fourth patient had fibrillary glomerulonephritis with kappa restriction, further evaluation of which led to diagnosis of chronic lymphocytic leukemia. Absence of "M" band in protein electrophoresis and a normal bone marrow study should not stop physicians from further evaluation. Quantitative serum immunofixation electrophoresis and electron microscopic examination of renal biopsy have become a comprehensive diagnostic tool in such patients.

9.
World J Clin Cases ; 12(17): 3200-3205, 2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38898862

RESUMO

BACKGROUND: Glomerulopathy with fibrillary deposits is not uncommon in routine nephropathology practice, with amyloidosis and fibrillary glomerulonephritis being the two most frequently encountered entities. Renal amyloid heavy and light chain (AHL) is relatively uncommon and its biopsy diagnosis is usually limited to cases that show strong equivalent staining for a single immunoglobulin (Ig) heavy chain and a single light chain, further supported by mass spectrometry (MS) and serum studies for monoclonal protein. But polyclonal light chain staining can pose a challenge. CASE SUMMARY: Herein we present a challenging case of renal AHL with polyclonal and polytypic Ig gamma (IgG) staining pattern by immunofluorescence. The patient is a 62-year-old Caucasian male who presented to an outside institution with a serum creatinine of up to 8.1 mg/dL and nephrotic range proteinuria. Despite the finding of a polyclonal and polytypic staining pattern on immunofluorescence, ultrastructural study of the renal biopsy demonstrated the presence of fibrils with a mean diameter of 10 nm. Congo red was positive while DNAJB9 was negative. MS suggested a diagnosis of amyloid AHL type with IgG and lambda, but kappa light chains were also present supporting the immunofluorescence staining results. Serum immunofixation studies demonstrated IgG lambda monoclonal spike. The patient was started on chemotherapy. The chronic renal injury however was quite advanced and he ended up needing dialysis shortly after. CONCLUSION: Tissue diagnosis of AHL amyloid can be tricky. Thorough confirmation using other available diagnostic techniques is recommended in such cases.

10.
J Lab Physicians ; 15(1): 162-165, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37064985

RESUMO

Laboratory investigations for any suspected case of solitary plasmacytoma of bone include routine biochemical and hematological investigations along with ß2-microglobulin, electrophoresis of serum protein and/or 24-hour urine protein, serum protein immunofixation (IFE), and nephelometric quantification of total immunoglobulin isotype and serum free light chain levels. Bone marrow aspirate and trephine biopsy are mandatory to confirm the absence of clonal plasma cells (for solitary plasmacytoma) or the presence of less than 10% clonal cells (solitary plasmacytoma with minimal bone marrow involvement). Imaging studies such as X-ray, computed tomography (CT), magnetic resonance imaging, and positron emission tomography/CT should be used to complement laboratory tests in diagnosis, staging, and defining the local extent of the plasmacytoma. However, guidelines regarding choice of technique for the detection of M band when monitoring a follow-up case of operated plasmacytoma are still not clear. Through this case study, we try to highlight the role of IFE in a follow-up case of operated solitary plasmacytoma of the bone.

11.
J Lab Physicians ; 15(4): 518-523, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37780881

RESUMO

Introduction Serum immunofixation electrophoresis (SIFE) and serum free light chain (SFLC) assay are imperative investigations in diagnosis and follow-up of multiple myeloma (MM). SFLC assays are reported to have higher sensitivity than SIFE. However, discrepancies have been reported between them. The current study was aimed at assessing concordance and discordance between SIFE and SFLC results in MM. Methods A total of 450 observations of both SIFE and SFLC were obtained from treatment-naive and follow-up MM patients. Results One hundred and twenty-nine (28.7%) values were observed as discordant, that is, positive SIFE with normal SFLC ratio or negative SIFE with abnormal SFLC ratio ( p -value < 0.00001). Proportion of discordance was higher in SIFE positive-SFLC normal cases than SIFE negative-SFLC abnormal cases. Discordance was more frequent in follow-up cases. Conclusion Negative SFLC alone may not be reliable for MM follow-up. Algorithm may be based on SFLC measurements on each follow-up till attainment of normal SFLC ratio. Once SFLC normalizes, follow-up may be done with SIFE. If SIFE is positive, further follow-up with SIFE may be initiated.

12.
Clin Biochem ; 108: 10-13, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35779576

RESUMO

Immunoassays are widely used in clinical laboratories because of their ease of use and low cost. These tests are based on antigen-antibody binding. However, clinicians and laboratory personnel may be confronted with immunoassay interference leading to difficulties in medical care. Here, we report a huge analytical discrepancy with IgG concentration higher than proteinemia in a 75-year-old man. Serum electrophoresis and immunofixation diagnosed γ-heavy chain disease. After investigation by different methods, the assay discrepancy was still present. We hypothesize that the interference is related to the truncated immunoglobulin secreted by the lymphoproliferative disorder.


Assuntos
Doença das Cadeias Pesadas , Idoso , Eletroforese , Doença das Cadeias Pesadas/diagnóstico , Humanos , Imunoeletroforese , Imunoglobulina G , Cadeias Leves de Imunoglobulina , Masculino
13.
Pract Lab Med ; 24: e00200, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33490350

RESUMO

Here we described a case of an asymptomatic 73 years-old female patient in geriatric routine consultation, whose laboratory testing showed hyperproteinemia with accompanying hyperglobulinemia. A diagnosis of BGUS was made only after a correlation among SPEP, densitometry tracing and IFE results was established, evidencing a second peak, that was less evident and not reported at first. These biclonal conditions are of very low incidence in the clinical laboratory, requiring the laboratory professional to have particular skills for their identification. As far as is known, clinical findings in BGUS are similar to those found in MGUS. However, they remain not well understood. Therefore, for an accurate diagnosis of BGUS, the clinical laboratory technician must be trained and sensitized to detect a second M - protein as a band or peak; taking in mind the possible different scenarios in heavy and light chain typing.


Se describe el caso de paciente asintomática de 73 años de edad en consulta geriátrica de rutina, cuyos estudios de laboratorios muestran hiperproteinemia acompañada de hiperglobulinemia. Se estableció el diagnóstico de GBSI después de correlacionar entre resultados de electroforesis de proteínas, trazo de densitometría e inmunofijación en suero, los cuales evidenciaron un segundo pico monoclonal menos evidente y no reportado de primera instancia. Este tipo de condiciones biclonales son de muy baja incidencia en laboratorio clínico, lo cual requiere que profesional de laboratorio tenga ciertas habilidades para su identificación. Hasta donde se conoce, los hallazgos clínicos de GBSI son similares a aquellos encontrados en GMSI. Sin embargo, continúan sin ser bien comprendidas. Por tanto, a fin de un diagnóstico más preciso, el técnico de laboratorio debe estar entrenado y sensibilizado para encontrar una segunda proteína M como banda o pico, tomando en cuenta los diferentes posibles escenarios en la tipificación de cadenas pesadas y ligeras.

14.
World J Clin Cases ; 9(11): 2576-2583, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33889623

RESUMO

BACKGROUND: Immunoglobulin D (IgD) multiple myeloma (MM) is a rare subtype of MM and commonly occurs in younger subjects but at a later stage of the International Staging System (ISS) when admitted. As a special type of IgD myeloma, IgD-λ/λ biclonal MM is rarer. Its serum protein electrophoresis and serum immuno-fixation electrophoresis (IFE) might find no anomalies even if the bone marrow (BM) examination is performed. Thus, it is easy to miss the diagnosis. CASE SUMMARY: A 62-year-old man diagnosed as IgD-λ/λ myeloma (ISS stage III) was admitted with fatigue and weight loss. The physical examination suggested an anemic face, a few moist rales at the left lung base, and mild concave edema in both lower extremities. Laboratory examinations showed the elevated creatinine levels, ß2-microglobulin, lactic dehydrogenase, and erythrocyte sedimentation rate, while the decreased neutrophils, granulocytes, and hemoglobin. In the serum protein electrophoresis, there appeared two inconspicuous M-spikes. Serum IFE indicated an over-representation of lambda light chain and yielded two monoclonal bands in λ region, but only one corresponding heavy chain band in the antisera to IgD region. The BM histology and BM cytology both supported the diagnosis of IgD-λ/λ myeloma. CONCLUSION: This case highlights the differential clinical manifestations and laboratory findings of IgD-λ/λ myeloma to help minimize the chance of misdiagnosis.

15.
J Clin Exp Hepatol ; 11(2): 270-272, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33746454

RESUMO

Hypercalcemia is a rare metabolic abnormality seen in patients with cirrhosis and is usually considered a paraneoplastic manifestation of hepatocellular carcinoma. Idiopathic hypercalcemia in cirrhosis is a diagnosis of exclusion, which is considered when all the causes of hypercalcemia have been ruled out. Here, we report a rare case of idiopathic hypercalcemia presenting as acute kidney injury in a case of decompensated cirrhosis, managed with adequate hydration and injection of ibandronate and intranasal calcitonin, leading to the normalization of serum calcium and resolution of acute kidney injury.

16.
Curr Res Transl Med ; 68(2): 67-70, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31761679

RESUMO

BACKGROUND: Plasma cell dyscrasias (PCD) are a heterogeneous group of diseases characterized by the expansion of monoclonal bone marrow plasma cells that produce a monoclonal immunoglobulin (M-component). PURPOSE: This is a retrospective study that describes the epidemiological, immunochemical features and etiology of monoclonal gammopathies diagnosed between 1998 and 2016 in the Teaching Hospital Beni-Messous of Algiers. PATIENTS AND METHODS: 2121 cases of monoclonal gammopathies (MG) were collected during this period. Serum/urine protein electrophoresis, serum/urine immunofixation and serum free light chain measurements were used to demonstrate M protein. RESULTS: The middle age of the patients at the time of the diagnosis were 62.96 ± 13.19 years with extremes ranging from 07 to 99 years. The study included 1013 (47, 76 %) men and 1108 (52, 23 %) women with a sex ratio 0,91. Isotypes repartition was: IgG (60.91 %), IgA (17.91 %), light chain (10.46 %), IgM (6.6 %), IgD (1.03 %) and IgE (0.09 %) of cases. The most frequent diagnosis was: Multiple Myeloma (55.20 %), followed by monoclonal gammopathy of undetermined significance (34.13 %). CONCLUSION: In our study, two particularities were noted. There is no male predominance in Algerian PCD patients. Moreover, we observed a higher frequency of light chain multiple myeloma and lower frequency of IgM isotype compared to western studies.


Assuntos
Isotipos de Imunoglobulinas/sangue , Paraproteinemias/epidemiologia , Paraproteínas/análise , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Argélia/epidemiologia , Criança , Comorbidade , Feminino , Humanos , Isotipos de Imunoglobulinas/urina , Cadeias Leves de Imunoglobulina/sangue , Cadeias Leves de Imunoglobulina/urina , Imunoglobulina M/sangue , Imunoglobulina M/urina , Masculino , Pessoa de Meia-Idade , Gamopatia Monoclonal de Significância Indeterminada/sangue , Gamopatia Monoclonal de Significância Indeterminada/epidemiologia , Mieloma Múltiplo/sangue , Mieloma Múltiplo/epidemiologia , Mieloma Múltiplo/urina , Paraproteinemias/sangue , Paraproteinemias/urina , Paraproteínas/urina , Estudos Retrospectivos , Distribuição por Sexo , Adulto Jovem
17.
Lab Med ; 50(4): 357-363, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-30915470

RESUMO

BACKGROUND: The production of 2 monoclonal proteins characterizes biclonal gammopathic manifestations (BGMs). The available medical literature from India is chiefly restricted to case reports. OBJECTIVE: To study the incidence of BGMs in a tertiary care center in Chandigarh, India, during a 4-year period. We evaluated these cases further for their laboratory characteristics. METHODS: We scrutinized the contents of a database containing information from the studied 4-year period. Cases reported as BGMs on serum protein electrophoresis (SPEP) and confirmed by serum immunofixation electrophoresis (SIFE) were included. RESULTS: A total of 15 cases, from a cohort of 914 cases of monoclonal gammopathic manifestations (MGMs), were available. On SPEP, 2 M bands were observed in 12 cases. On SIFE, 4 cases were reported as being of true BGMs. The most common heavy-chain combination observed was immunoglobulin (Ig)A-IgG. Follow-up was available in 2 patients. CONCLUSION: Identification of BGMs increases diagnostic precision, despite that the treatment is similar to that for monoclonal gammopathic manifestations (MGMs). BGMs can be transitory and may be observed at presentation or during the disease course.


Assuntos
Paraproteinemias/epidemiologia , Paraproteinemias/patologia , Idoso , Idoso de 80 Anos ou mais , Eletroforese , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Incidência , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Centros de Atenção Terciária
18.
Ann Biol Clin (Paris) ; 75(3): 351-355, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28540859

RESUMO

We report the case of a 54 years old patient monitored for a monoclonal IgG kappa light chain refractory relapsed multiple myeloma and receiving daratumumab immunotherapy. Daratumumab (DARA), a monoclonal anti-CD38 antibody, belongs to the new generation of immunotherapy in refractory relapse multiple myeloma which the medical pathologist should be aware of to avoid misinterpretation of biological tests performed for patients followed for this disease. By its IgG1K humanized monoclonal antibody backbone, DARA interferes in both serum protein electrophoresis and immunofixation by the presence of an alternate IgGK monoclonal peak, leading to a possible difficulty to assess treatment's response in monoclonal IgG kappa light chain myeloma. By its intrinsic anti-CD38 activity DARA also interferes in the screening and identification of red blood cells alloantibodies, due to stabilized red cells reagent expressing weakly the CD38 molecule. We manage to overcome this last interference by using dithiotreitol.


Assuntos
ADP-Ribosil Ciclase 1/imunologia , Anticorpos Monoclonais/uso terapêutico , Autoanticorpos/análise , Eritrócitos/imunologia , Imunoglobulina G/sangue , Glicoproteínas de Membrana/imunologia , Mieloma Múltiplo/tratamento farmacológico , Testes Sorológicos , Anticorpos Monoclonais/sangue , Anticorpos Monoclonais/metabolismo , Autoanticorpos/sangue , Reações Cruzadas , Eritrócitos/metabolismo , Reações Falso-Positivas , Feminino , Humanos , Imunoglobulina G/efeitos adversos , Pessoa de Meia-Idade , Mieloma Múltiplo/sangue , Mieloma Múltiplo/imunologia , Testes Sorológicos/normas
19.
Oncol Lett ; 12(4): 2363-2370, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27698801

RESUMO

Monoclonal gammopathies are characterized by serum monoclonal component (MC) plus an intact immunoglobulin and a free light chain (FLC), or a combination of both. The measurement of FLC with Freelite® is the standard practice recommended by International Myeloma Working Group guidelines. Recently, Hevylite® heavy/light chains (HLC) assays were introduced to specifically target junctional epitopes between the heavy and light chains of intact immunoglobulins, allowing the independent quantification of the involved (MC) and uninvolved (polyclonal immunoglobulin background) HLC isotype. Between January 2012 and March 2014, 90 patients were examined: 49 multiple myeloma (MM), 6 smoldering MM (SMM) and 35 monoclonal gammopathy of undetermined significance (MGUS). Of these 90 patients, 300 samples were collected at different times. The diagnostic and monitoring contribution of Hevylite A and G assays was assessed in all 90 patients examined. Additionally, 3 representative cases were selected. The Hevylite absolute values and ratio demonstrated high sensitivity and specificity with respect to serum protein electrophoresis and serum immunofixation. The combined use of Hevylite A and G with Freelite was particularly useful in dubious cases with more than one MC or with co-migrating components, as well as in the course of monitoring to assess the independent change of FLC and HLC, possibly reflecting the presence of clonal heterogeneity in the cohort. From this study, it can be concluded that FLC and HLC are independent, useful markers to monitor the MC and to assess with greater specificity and sensitivity the effect of therapy, thereby providing clinical support. Further studies are required to assess the prognostic potential of Hevylite in MGUS and SMM.

20.
Clin Chim Acta ; 439: 68-70, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25307209

RESUMO

BACKGROUND: Different patterns between serum immunofixation electrophoresis (SIFE) and urine immunofixation electrophoresis (UIFE) happen occasionally and laboratorians should understand the mechanisms behind the differences and additional tests required for complicated cases. METHODS: We investigated a complicated multiple myeloma case that showed inconsistent patterns of SIFE and UIFE. To differentiate monoclonal proteins (M-proteins), the urine sample was treated with dithiothreitol to open up the IgA molecule and urine free light chain assay was used for free light chain analysis. RESULTS: The patient's SIFE indicated 2 IgA λ and 1 IgM κ M-proteins, while UIFE revealed monoclonal free λ light chains and a suspicious monoclonal IgA κ protein. Subsequent treatment of the urine sample with dithiothreitol and urine free light chain assay demonstrated that the suspicious monoclonal IgA κ protein was actually a monoclonal IgA λ and a free κ light chain that had similar electrophoretic mobility. CONCLUSIONS: The differences identified between SIFE and UIFE in this case are due to the limitation of immunofixation electrophoresis on different specimen types and intra-molecular disulfide bonds formation in IgA. The laboratorians must be cognizant of the strengths and limitations of the procedure being performed and the ancillary testing techniques available to solve the problem.


Assuntos
Anticorpos Monoclonais/sangue , Anticorpos Monoclonais/urina , Imunoeletroforese , Cadeias kappa de Imunoglobulina/sangue , Cadeias kappa de Imunoglobulina/urina , Cadeias lambda de Imunoglobulina/sangue , Cadeias lambda de Imunoglobulina/urina , Idoso , Humanos , Masculino , Mieloma Múltiplo/sangue , Mieloma Múltiplo/urina
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