Summary
Circulating free light chains (FLCs), considered biomarkers of B cell activity, are frequently elevated in patients affected by systemic inflammatory autoimmune diseases. As the systemic ...sclerosis (SSc) clinical course can be variable, this study is aimed at evaluating FLCs levels in affected individuals as biomarkers of disease activity. We assessed FLC levels in serum and urine of 72 SSc patients and 30 healthy controls (HC). Results were analyzed in comparison with overall clinical and laboratory findings, disease activity index (DAI) and disease severity scale (DSS). SSc patients displayed increased levels of κ and λ FLC in serum significantly higher than HC (p = 0.0001) alongside the mean values of free κ/λ ratio and κ + λ sum (p = 0.0001). SSc patients showed increased free κ in urine with a κ/λ higher than HC (p = 0.0001). SSc patients with increased κ + λ in serum showed that erythro‐sedimentation rate (p = 0.034), C‐reactive protein (p = 0.003), DAI (p = 0.024) and DSS (p = 0.015) were higher if compared to SSc patients with normal levels of FLC. A positive linear correlation was found between serum levels of free κ and DAI (r = 0.29, p = 0.014). In addition, SSc patients with increased free κ in urine had higher DAI (p = 0.048) than SSc patients with normal κ levels. Our results strengthen the role of serum FLC as useful biomarker in clinical practice to early diagnosis and monitor disease activity, showing for the first time that also urine FLC levels correlated with disease activity in SSc patients.
SSc patients show increased serum levels of k and λ FLC alongside with the mean values of free k+λ sum and k/λ ratio in comparison to HD. The urinary FLC profile of SSc patients mostly parallels the serological one. Serum and urinary FLC may act as useful biomarkers in management of SSc patients.
Use of biomarkers to diagnose and manage cardiac amyloidosis Castiglione, Vincenzo; Franzini, Maria; Aimo, Alberto ...
European journal of heart failure,
February 2021, 2021-Feb, 2021-02-00, 20210201, Letnik:
23, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Amyloidoses are characterized by the tissue accumulation of misfolded proteins into insoluble fibrils. The two most common types of systemic amyloidosis result from the deposition of immunoglobulin ...light chains (AL) and wild‐type or variant transthyretin (ATTRwt/ATTRv). Cardiac involvement is the main determinant of outcome in both AL and ATTR, and cardiac amyloidosis (CA) is increasingly recognized as a cause of heart failure. In CA, circulating biomarkers are important diagnostic tools, allow to refine risk stratification at baseline and during follow‐up, help to tailor the therapeutic strategy and monitor the response to treatment. Among amyloid precursors, free light chains are established biomarkers in AL amyloidosis, while the plasma transthyretin assay is currently being investigated as a tool for supporting the diagnosis of ATTRv amyloidosis, predicting outcome and monitor response to novel tetramer stabilizers or small interfering RNA drugs in ATTR CA. Natriuretic peptides (NPs) and troponins are consistently elevated in patients with AL and ATTR CA. Plasma NPs, troponins and free light chains hold prognostic significance in AL amyloidosis, and are evaluated for therapy decision‐making and follow‐up, while the value of NPs and troponins in ATTR is less well established. Biomarkers can be usefully integrated with clinical and imaging variables at all levels of the clinical algorithm of systemic amyloidosis, from screening to diagnosis and prognosis, and treatment tailoring.
Background: Multiple myeloma (MM) is a malignant neoplasm characterized by the clonal expansion of plasma cells that can release monoclonal immunoglobulins (monoclonal component) or part of theme. ...Since 2001, the k and λ serum free light chains (sFLC) evaluation and their ratio (rFLC) have made up the laboratory analysis more sensitive and precise in MM patients. The role of rFLC has been widely studied and discussed and now it is validated in the literature. Instead, the value of free light chains difference (dFLC), especially in MM is less known yet. The aim of this study is to evaluate the relationship between the dFLC and the kidney damage parameters in patients with MM, in comparison with the rFLC value.
Methods: We conducted a retrospective population-based study on 58 MM patients and we individuated two groups obtained considering the measures of dFLC and rFLC in relation to abnormal and normal values of some renal function markers, such us Bence-Jones proteinuria (BJ), albuminuria, proteinuria and serum creatinine. The Mann-Whitney test was used to test the difference between two independent samples.
Results: We observed a significant greater mean score of dFLC in patients with abnormal levels of BJ (2322.91>297.47, p=0.0001), albuminuria (2650.61>671.37, p=0.0016) and proteinuria (2327.19>593.14, p= 0.0025), while there was no significant difference for serum creatinine (1636.18<1870.85, p=0.994). Instead, no differences were observed for the rFLC parameter.
Conclusion: The data obtained allow us to conclude that dFLC can be considered a potential predictor of renal damage in MM patients, even better than rFLC.
Increasing evidence is available about the presence of increased serum concentration of immunoglobulin (Ig) free light chains (FLCs) in both atopic and non-atopic inflammatory diseases, including ...severe asthma, providing a possible new biomarker of disease.
We analyzed clinical and laboratory data, including FLCs, obtained from a cohort of 79 asthmatic subjects, clinically classified into different GINA steps. A control group of 40 age-matched healthy donors (HD) was considered. Particularly, HD have been selected according to the absence of monoclonal components (in order to exclude paraproteinemias), were tested for total IgE (that were in the normal ranges) and were negative for aeroallergens specific IgE. Moreover, no abnormality of common inflammatory markers (i.e., erythrocyte sedimentation rate and C-reactive protein) was detectable.
FLC-k levels were significantly increased in the asthmatic population, compared to the control group. Despite the absence of statistically significant differences in FLC-λ levels, the FLC-k/FLC-λ ratio displayed remarkable differences between the two groups. A positive correlation between FLC-κ and FLC-λ levels was found. FLC- λ level displayed a significant negative correlation with the FEV1 value. Moreover, the FLC-κ /FLC- λ ratio was negatively correlated with the SNOT-22 score and a positive correlation was observed between FLCs and Staphylococcus Aureus IgE enterotoxins sensitization.
Our findings confirmed the role of FLCs in asthma as a potential biomarker in an inflammatory disease characterized by different endotypes and phenotypes. In particular, FLC-κ and FLC-k/FLC-λ ratio could be a qualitative indicator for asthma, while FLC-λ levels could be a quantitative indicator for clinical severity parameters.
Amyloidosis refers to a clinically heterogeneous group of disorders characterized by the extracellular deposition of amyloid proteins in various tissues of the body. To date, 42 different amyloid ...proteins that originate from normal precursor proteins and are associated with distinct clinical forms of amyloidosis have been described. Identification of the amyloid type is essential in clinical practice, since prognosis and treatment regimens both vary according to the particular amyloid disease. However, typing of amyloid protein is often challenging, especially in the two most common forms of amyloidosis, i.e., the immunoglobulin light chain amyloidosis and transthyretin amyloidosis. Diagnostic methodology is based on tissue examinations as well as on noninvasive techniques including serological and imaging studies. Tissue examinations vary depending on the tissue preparation mode, i.e., whether it is fresh-frozen or fixed, and they can be carried out by ample methodologies including immunohistochemistry, immunofluorescence, immunoelectron microscopy, Western blotting, and proteomic analysis. In this review, we summarize current methodological approaches used for the diagnosis of amyloidosis and discusses their utility, advantages, and limitations. Special attention is paid to the simplicity of the procedures and their availability in clinical diagnostic laboratories. Finally, we describe new methods recently developed by our team to overcome limitations existing in the standard assays used in common practice.
Abstract
AL amyloidosis (light chain; previously also called primary amyloidosis) is a systemic disease characterized by an amyloid deposition process affecting many organs, and which still has ...unsatisfactory survival of patients. The monoclonal light chains kappa (κ) or lambda (λ) or their fragments form the fibrils that deposit and accumulate in different tissues. Renal involvement is very frequent in AL amyloidosis and can lead to the development of nephrotic syndrome followed by renal failure in some cases. AL amyloidosis ultimately leads to destruction of tissues and progressive disease. With recent advances in the treatment, the importance of an early diagnosis of amyloidosis and correct assessment of its type is high. Histologic confirmation is based on Congo red detection of amyloid deposits in tissues but AL amyloidosis must also be distinguished from other systemic forms of amyloidoses with renal involvement, such as AA amyloidosis, amyloidosis with heavy chain deposition, fibrinogen Aα or ALECT2 (leukocyte chemotactic factor 2) deposition. Immunofluorescence (IF) plays a key role here. IF on formalin-fixed paraffin-embedded tissue after protease digestion, immunohistochemistry or laser microdissection with mass spectrometry should complete the diagnosis in unclear cases. Standard treatment with melphalan and prednisolone or with cyclophosphamide and dexamethasone has been replaced with newer drugs used for the treatment of multiple myeloma—bortezomib, carfilzomib and ixazomib or thalidomide, lenalidomide and pomalidomide. High-dose melphalan supported by autologous stem cell transplantation remains the therapeutic option for patients with low-risk status. These new treatment options prolong survival from months to years and improve the prognosis in a majority of patients.
This study was performed in real clinical practice settings. Our paper describes two case studies which show the difficulty of differential diagnosis of monoclonal gammopathies, multiple myeloma ...associated with AL-amyloidosis and primary AL-amyloidosis.
Cerebrospinal fluid (CSF) free light chains (FLC) may be an alternative biomarker to oligoclonal bands (OCB) in multiple sclerosis (MS). Herein, we compared the diagnostic accuracy of CSF OCB and FLC ...and we tested the prognostic value of FLC in a cohort of 64 MS patients and 106 controls. A κ-index >7.83 was more sensitive but less specific than OCB in discriminating MS patients from controls. Additionally, a κ-index >10.61 performed better than OCB in the discrimination between MS and controls with inflammatory neurological diseases (p < .001). In clinically isolated syndrome (CIS) patients, a κ-index >10.61 significantly predicted time to conversion to MS (p = .020). κ-index might be a valid alternative to OCB as a diagnostic biomarker for MS and might also be a prognostic marker in CIS.
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•κ-index is more sensitive and less specific than OCB for MS diagnosis.•κ-index performs better than OCB in discriminating MS from other inflammatory neurological diseases.•κ-index correlates with different disease characteristics in MS.•κ-index predicts disease activity in early MS patients.
Objective
To estimate levels of salivary and serum free light chains (FLCs) and explore its utility as a biomarker in primary Sjögren's syndrome (pSS).
Methods
Patients with pSS classified by ...American European Consensus group 2002 or American College of Rheumatology 2012 criteria between January 2015 and August 2015 were included. Healthy staff and non‐first degree relatives of patients constituted controls. Serum and salivary FLCs were measured by immunoturbidometry using FREELITE™ Human Kappa(κ) and Lambda(λ) Free Kit (Binding site, Birmingham, UK), on a Roche Modular P800. FLCs were compared between cases and controls using the Mann‐Whitney U‐test. The receiver operator characteristic curve was constructed to analyze the discriminating ability of salivary and serum kappa and lambda FLCs.
Results
Salivary and serum FLCs were assayed in 15 patients and 13 patients, respectively, and in 15 controls. Median age of cases and controls was 34 years. Salivary kappa and lambda FLCs were higher in pSS as compared to controls (P < 0.05 and P < 0.001, respectively). Serum kappa and lambda FLCs were also higher in pSS (both P < 0.05). Salivary lambda levels were higher in pSS with ocular signs; serum kappa and lambda levels were higher in those with ocular symptoms. A cut off of ≥ 1.1 mg/L for salivary lambda FLC had a sensitivity and specificity of 73.3% and 93.3%, respectively, for the diagnosis of pSS. Serum kappa FLC ≥ 30 mg/L had a sensitivity and specificity of 92.3% and 73.3%, respectively.
Conclusion
Serum and salivary FLCs and in particular the latter, are potential biomarkers in pSS. Larger studies are required for validating the findings.
Apolipoprotein E (APOE) is recognized for its role in modulating blood-brain barrier (BBB) permeability in vitro, which may have significant implications for the pathogenesis and progression of ...neurodegenerative disorders. However, evidence in vivo is contrasting. This study explores the impact of APOE genotypes on BBB integrity among 230 participants experiencing cognitive impairment, encompassing cases of Alzheimer's disease (AD) as well as various non-AD neurodegenerative conditions. To assess BBB integrity, we utilized cerebrospinal fluid (CSF)/serum albumin ratios and CSF/serum kappa and lambda free light chains (FLCs) as indirect markers. Our findings show a dose-dependent increase in BBB permeability in individuals carrying the APOE ε4 allele, marked by elevated CSF/serum albumin and FLCs ratios, with this trend being especially pronounced in AD patients. These results highlight the association of APOE ε4 with BBB permeability, providing valuable insights into the pathophysiology of neurodegenerative diseases.
•CSF/serum albumin ratio increased in heterozygous and homozygous APOE ε4 carriers.•Kappa and lambda CSF/serum FLCs ratios increased in homozygous APOE ε4 carriers.•APOE ε4 associated with increased BBB permeability in AD and non-AD participants.
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