OBJECTIVETo investigate the clinical significance of serum free light chain (sFLC) detection in light chain multiple myeloma (LCMM).

METHODSA total of 37 newly diagnosed LCMM patients were enrolled in this study, including 17 patients with k light chain type and 20 patients with λ light chain type, the sFLC and 24 hours urine light chain (ULC) were measured before and after chemotherapy. The correlation of sFLC level with ULC and renal impairment was analyzed.

RESULTSAll the patients displayed an abnormally increased level of sFLC at diagnosis wtih median value of 105.44 mg/L and 146.39 mg/L for k and λ light chain types, respectively. The sFLC did not correlate with ULC before and after chemotherapy. Among the 12 patients with very good partial remission and normal ULC level, the sFLC still was abnormally increased in 8 patients. Renal impairment was associated with the urine λ-type light chain, and the area under the ROC curve of urine λ light chain at diagnosis is 0.792 (P = 0.031).

CONCLUSIONAll patients with LCMM show an abnormally increased level of sFLC at diagnosis. sFLC can be used to monitor the response to chemotherapy because it is more sensitive for analysis of therapeutic effect than urine λ light chain.

Humans ; Immunoglobulin Light Chains ; blood ; Immunoglobulin kappa-Chains ; blood ; Immunoglobulin lambda-Chains ; blood ; Multiple Myeloma ; blood ; drug therapy ; Renal Insufficiency

Humans ; Immunoglobulin A ; blood ; Immunoglobulin Light Chains ; blood ; Leukemia ; blood ; Multiple Myeloma ; blood

Humans ; Immunoglobulin Light Chains ; blood ; chemistry ; immunology ; Kidney ; immunology ; pathology ; Paraproteinemias ; immunology

OBJECTIVE: To investigate the correlation between serum free light chain (sFLC) and blood routine parameters in patients with multiple myeloma (MM). METHODS: 347 patients with multiple myeloma diagnosed in Sichuan people's Hospital from April 2019 to July 2021 were selected. sFLC, serum total light chain (sTLC), peripheral blood routine, coagulation and biochemical parameters were analyzed retrospectively. The correlation analysis between sFLC and blood routine parameters were calculated by Pearson or Spearman correlation coefficients. Multiple stepwise linear regression was used to screen the combined blood routine parameters related to sFLC. The efficacy of the selected blood routine parameters eflecting sFLC level was evaluated, the Kruskal Wallis test of independent samples was used for inter group comparison, and the receiver operating characteristic (ROC) curve was drawn at the same time. RESULTS: In MM patients, sFLC was positively related with sTLCκ, sTLCλ, sTLCκ/λ, Cr, Urea, Cr and Cys_C significantly, while negatively correlated with eGFR markedly (｜r｜≥0.3). Multivariate stepwise linear regression showed that the influence factors of sFLCκ were Cr and sTLCκ (P=0.000, P=0.003), the influence factors of sFLCλ were eGFR and sTLCλ(P=0.000, P=0.000), the sFLCκ/λ influence factor was sTLCκ/λ (P=0.032). Kruskal Wallis test of independent samples showed that Cr and sTLCκ, eGFR and sTLCλ, TLCκ/λ were good or better parameters to reflect the level of sFLCκ, sFLCλ and sFLCκ/λ in MM patients(P＜0.05), respectively. ROC curve analysis shows that Cr, sTLCκ, eGFR, sTLCλ and sTLCκ/λ had the ability to judge the abnormality of sFLC in MM patients (AUC=0.684-0.875, P＜0.05). CONCLUSION In MM patients, sTLCκ and sTLCλ with renal function parameters could evaluate sFLCκ or sFLCλ level respectively, while sFLC κ/λ was estimated by sTLCκ/λ.
Blood Coagulation Tests ; Humans ; Immunoglobulin Light Chains ; Multiple Myeloma ; Retrospective Studies ; Urea

BACKGROUND: Korea is an endemic area of scrub typhus and it is a common seasonal febrile illness. Although, various humoral immune responses to scrub typhus have been documented, no association between gammopathy and scrub typhus has ever been reported. We analyzed the incidences and types of monoclonal and biclonal gammopathies in scrub typhus for better coping with those gammopathies in scrub typhus. METHODS: Anti-Orientia tsutsugamushi antibody-positive sera identified by indirect immunofluorescence assay were acquired from 40 patients with confirmed scrub typhus. Monoclonal and biclonal gammopathies were screened by protein electrophoresis and were confirmed using immunofixation electrophoresis (IFE). Laboratory findings on admission of the patients with monoclonal or biclonal gammopathy were investigated retrospectively to characterize the gammopathies. RESULTS: Monoclonal or biclonal gammopathies were detected in 30% (12/40) of patients with scrub typhus (IgG-lambda, 40%; IgG-kappa, 30%; IgM-kappa, 10%; IgM-lambda, 10%; IgA-kappa, 5%; IgA-lambda, 5%). Concentrations of clonal immunoglobulin were less than 3 g/dL in all gammopathies, and hypercalcemia was not detected in any of the patients. CONCLUSIONS: Our results suggest possible association between gammopathies and scrub typhus. Further studies in larger series will be needed for exact incidence and clinical course of gammopathies in scrub typhus.
Adult ; Aged ; Humans ; Immunoglobulin A/blood ; Immunoglobulin G/blood ; Immunoglobulin Heavy Chains/blood ; Immunoglobulin Light Chains/blood ; Immunoglobulin M/blood ; Incidence ; Middle Aged ; Orientia tsutsugamushi/immunology ; Paraproteinemias/complications/*diagnosis/epidemiology/immunology ; Retrospective Studies ; Scrub Typhus/complications/*diagnosis/immunology

OBJECTIVETo explore the clinical significance of serum free light chain (sFLC) levels in nonsecretory multiple myeloma (NSMM).

METHODSNine NSMM patients were hospitalized in our department from Feb 2002 to Sep 2006 and no M-components was found in their serum and urine by immunofixation electrophoresis (IFE). sFLC was assayed by immuno-nephelometry. The clonality of sFLC was estimated by serum kappa:lambda sFLC ratio. Meanwhile, serum immunoglobulin, total kappa and lambda light chain level were also determined in these patients.

RESULTSIncreased serum concentrations of either kappa or lambda sFLC (and abnormal kappa/lambda ratios) were detected in 6 of 9 patients with NSMM although their serum immunoglobulin levels were not elevated and total kappa:lambda light chain ratios (1.32 - 2.20) were in the reference range. All the 9 patients had clonal IgH gene rearrangements.

CONCLUSIONQuantification of sFLC by immuno-nephelometry is more sensitive than that of serum total light chain measurement and is helpful in estimating the clonality of the light chain in patients with NSMM.

Adult ; Female ; Humans ; Immunoglobulin Light Chains ; blood ; Male ; Middle Aged ; Multiple Myeloma ; blood ; Nephelometry and Turbidimetry ; Sensitivity and Specificity

OBJECTIVETo investigate the significance of serum IgD quantitation in evaluation of clinical efficacy in IgD myeloma.

METHODSSerum IgD and free light chain (sFLC) levels were determined by immune scatter turbidimetry with SPA plus analysis machine in 29 patients with IgD multiple myeloma (MM) achieving VGPR or better response following previous treatments. The concurrent immunofixation electrophoresis (IFE) results were also incorporated and analyzed.

RESULTSIncreased IgD levels were detected in 1 of 12 patients achieving sCR, 2 of 5 patients achieving CR and 4 of 12 patients achieving VGPR, respectively. The median progression-free survival (PFS) was 38.5 months, 34.1 months and 15.5 months for patients achieving sCR, CR and VGPR, respectively, with a significant difference between sCR and VGPR groups (P=0.022), and between CR and VGPR groups (P=0.018). There was no difference in overall survival (OS) among sCR, CR and VGPR groups (P>0.05). The median PFS were 7.8, 33.7 and 43.9 months, respectively for the patients with both abnormal sFLC ratios and IgD levels (6 cases, Group A), with either abnormal sFLC ratios or increased IgD levels (10 cases, Group B) or with normal sFLC ratios and IgD levels (13 cases, Group C). A significant PFS benefit of Group A over Group C was found (P=0.033), and no differences in terms of OS among three groups (P>0.05).

CONCLUSIONIgD levels may remain abnormal in IgD MM patients who have achieved VGPR or better response, and IgD quantitation represented a useful assay complementary to the current lab examinations. IgD quantitation assay was of significance in clinical efficacy evaluation and survival judgement, and should be incorporated into the evaluation parameters used for IgD MM in addition to sFLC and IFE assays.

Disease-Free Survival ; Humans ; Immunoglobulin D ; blood ; Immunoglobulin Light Chains ; blood ; Multiple Myeloma ; blood ; diagnosis ; Nephelometry and Turbidimetry ; Remission Induction ; Treatment Outcome

Multiple myeloma (MM) is a malignant disorder characterized by the proliferation of a single clone of plasma cells that can produce excessive amounts of serum free light chain (sFLC). sFLC plays an important role in MM diagnosis and disease monitoring. The quantitative immuno-nephelometric assay is sensitive and specific means for sFLC testing. The aim of this study was to investigate the levels of sFLC in multiple myeloma and the relationship between sFLC and serum total light chain (sTLC). sFLC in 45 newly diagnosed patients were detected by immuno-nephelometric assay, and then the ratio of free kappa to free lambda for every sample was calculated. Meanwhile, sTLC was also determined in these patients. The results showed that the difference of sFLC levels between MM patients and the normal controls was significant (tΚ = 8.86, P < 0.001; tλ = 15.48, P < 0.001;tΚ/λ = 5.54,P < 0.005). No correlation between sFLC and sTLC was found in MM patients. It is concluded that the level of sFLC in MM patients is significantly higher than that in normal controls. sFLC and its ratio may be served as a indicator for diagnosis of MM. sTLC can not replace the role of sFLC.
Adult ; Aged ; Aged, 80 and over ; Biomarkers, Tumor ; blood ; Case-Control Studies ; Female ; Humans ; Immunoglobulin Light Chains ; blood ; Male ; Middle Aged ; Multiple Myeloma ; blood

The present study was undertaken to produce monoclonal antibodies (MAbs) against immunoglobulin (Ig) purified from black rockfish (Sebastes schlegeli Higendorf) serum using protein A, mannan binding protein, and goat IgG affinity columns. These three different ligands were found to possess high affinity for black rockfish serum Ig. All of the Igs purified eluted at only 0.46 M NaCl concentration in anion exchange column chromatography and consisted of two bands at 70 kDa and 25 kDa in SDS-PAGE; they also had similar antigenicity for MAbs to Ig heavy chain in immunoblot assays. Therefore, black rockfish Ig is believed to exist as a single isotype within serum. The MAbs produced against Ig heavy chain reacted specifically with spots distributed over the pI range from 4.8 to 5.6 with a molecular weight of 70 kDa on two dimensional gel electrophoresis immunoblot profiles.
Animals ; Antibodies, Monoclonal/*biosynthesis/immunology ; Chromatography, Affinity/veterinary ; Electrophoresis, Gel, Two-Dimensional/veterinary ; Immunoblotting/veterinary ; Immunoglobulin Heavy Chains/immunology ; Immunoglobulin Light Chains/immunology ; Immunoglobulins/blood/*immunology ; Perciformes/blood/*immunology

BACKGROUND: Free light chain (FLC) is widely used to evaluate B-cell proliferative diseases. Herein, we estimated the clinical usefulness of serum FLC in multiple myeloma (MM). METHODS: Fifty-one patients were enrolled. We performed FLC analysis, protein electrophoresis (PEP), and immunofixation electrophoresis (IFE). FLC was measured using Toshiba 200 FR Neo with FREELITE(TM), and kappa/lambda (kappa/lambda) ratio was calculated. We compared these parameters in 41 patients with increased FLC before and after bortezomib treatment. Complete response (CR) was defined as the disappearance of monoclonal (M) protein in serum and/or urine as measured by IFE. Partial response (PR) was defined as > or =50% reduction of serum M protein. Early objective response (EOR) included both CR and PR. Minimal response (MR) was defined as 25-49% reduction of M protein and stable disease (SD) as <25% reduction. RESULTS: Forty-one (80.4%) of the 51 patients studied revealed increment of FLC and the five patients with no increment revealed an abnormal kappa/lambda ratio. Especially, all of the light chain myeloma and non-secretory myeloma showed increased FLC concentrations. Among the patients with EOR, 72.4% (21/29) showed a normal or subnormal FLC concentration after the first cycle of treatment. Otherwise, PEP and IFE normalized in 24.1% (7/29) and 24.1% (7/29), respectively. The ratio of decreased FLC after the first cycle of treatment was significantly different between EOR and other response groups (MR, SD) (90.6% vs 51.8%, P=0.011). CONCLUSIONS: FLC was considered as a good diagnostic method in complement with PEP and IFE in MM, especially in light chain myeloma or non-secretory myeloma. Moreover, FLC is a useful monitoring tool because it reflects therapy results more rapidly owing to a short serum half-life.
Adult ; Aged ; Boronic Acids/therapeutic use ; Female ; Humans ; Immunoelectrophoresis ; Immunoglobulin Light Chains/*blood/urine ; Male ; Middle Aged ; Multiple Myeloma/*diagnosis/therapy ; Pyrazines/therapeutic use ; Reagent Kits, Diagnostic