Bad players in AL amyloidosis in the current era of treatment.

INTRODUCTION: Systemic AL amyloidosis (ALA) is a clonal plasma cell (PC) disease characterized by deposition of amyloid fibrils in different organs and tissues. Traditionally, the prognosis of ALA is poor and is primarily defined by cardiac involvement. The modern prognostic models are based on cardiac markers and free light chain difference (dFLC). Cardiac biomarkers have low specificity and are dependent on renal function, volume status, and cardiac diseases other than ALA. New therapies significantly improved the prognosis of the disease. The advancements in technologies - cardiac echocardiography (ECHO) and cardiac MRI (CMR), as well as new biological markers, relying on cardiac injury, inflammation, endothelial damage, and clonal and non-clonal PC markers are promising. AREAS COVERED: An update on the prognostic significance of cardiac ALA, number of involved organs, response to treatment, including minimal residual disease (MRD), ECHO, MRI, and new biological markers will be discussed. The literature search was done in PubMed and Google Scholar, and the most recent and relevant data are included. EXPERT OPINION: Prospective multicenter trials, evaluating multiple clinical and laboratory parameters, should be done to improve the risk assessment models in ALA in the modern era of therapy.

Retinal oxygen saturation in monoclonal gammopathies patients: A pilot study.

PURPOSE: The aim of this pilot study was to assess oxygen saturation in retinal blood vessels in patients with monoclonal gammopathies (MGs). METHODS: Thirty-one patients with MGs (11 women and 20 men, mean age 65.9 ± 8.9 years) were enrolled during 2016-2020. The patients were diagnosed at the Haemato-Oncology Department and subsequently examined at the Ophthalmology Department before initiating systemic therapy. All patients were subjected to automatic retinal oximetry (Oxymap ehf.) and had their fundus photographed (Topcon TRC-50DX retinal camera). We assessed the association between retinal oxygen saturation (SatO2 ) - arterial SatO2 , venous SatO2 and arterio-venous (AV) difference-and MGs parameters: serum monoclonal immunoglobulin (M-protein) level and serum immunoglobulin-free light chains (FLC kappa and lambda), total protein, serum viscosity, haemoglobin, albumin, lactate dehydrogenase, C-reactive protein, creatinine and serum calcium level. Hyperviscosity-related retinopathy was also evaluated. RESULTS: Statistical analysis showed a significant positive correlation (r = 0.462; p = 0.009) between the AV difference and the haemoglobin level. A significant, medium strong negative correlation was found between the AV difference and the serum levels of the monoclonal light lambda chains (r = -0.450; p = 0.011). Contrary to expectations, no statistically significant correlation was found between retinal oxygen saturation and the total protein or viscosity. CONCLUSION: This study found correlation between retinal oxygen saturation and certain parameters in the blood of patients with MGs. Increasing levels of monoclonal immunoglobulin seem to reduce oxygen absorption in retinal arterioles, resulting in a lower AV difference, particularly in patients with a high free light chain level.

K index utility as diagnostic and prognostic biomarker in the assessment of patients with suspected Multiple Sclerosis.

The aim of the present study is to evaluate the composite role of k index in the initial assessment of Multiple Sclerosis (MS) patients and to select useful cut-offs exportable in clinical practice. We analysed CSF/serum samples of 140 patients and followed-up the CIS/MS subgroup for 7 years. Our results suggest κ index as a quantitative diagnostic and prognostic biomarker in MS, significantly associated to baseline lesion load and to successive clinical course. We propose k index ≥106 as a prognostic cut-off to select patients at major risk of relapse, potentially influencing initial therapeutic decisions.

Biochemical profile of Bence-Jones type multiple myeloma.

Multiple myeloma (MM) is a malignant tumor occurring from plasma cells that produce an abnormal monoclonal immunoglobulin - a paraprotein. A distinctive feature of Bence-Jones myeloma is the excretion of monoclonal free light chains of immunoglobulins with 24h urine, and the absence of monoclonal intact immunoglobulins secretion. Comprehensive analysis of biochemical parameters in blood serum and 24h urine in patients with Bence-Jones multiple myeloma using electrophoretic and immunoturbidimetric methods to assess their sensitivity as biomarkers. 50 patients with a morphologically confirmed diagnosis of MM of the Bence-Jones immunochemical type were examined. 28 people without oncological diseases were examinedas a control. Detection of monoclonal secretion in blood serum and daily urine was performed by immunofixation electrophoresis on the Hydrasys 2 electrophoretic system (Sebia). The determination of free light chains of immunoglobulins (FLC) was performed by the immunoturbidimetric method (Binding Site) on an Advia 1800 analyzer (Siemens). Analysis of IgG, IgA, IgM, ß2-microglobulin and C-reactive protein was performed on Cobas 6000 analyzer (Roche). The median excretion of Bence-Jones protein in 24h urine of MM patients was 0.49 g/24h (0.06-2.45 g/24h). In the blood serum, in 86% of cases, the presence of paraproteinemia, represented by κ and λ type light chains of immunogloublins was detected. At the same time, the frequency of detection of monoclonal secretion in blood serum in Bence-Jones type λ myeloma was 95.7%, which was statistically significantly higher than the frequency of detection of monoclonal secretion of type κ - 77.8%. In patients with identified paraproteinemia, Bence-Jones protein excretion in daily urine (median 0.82 g/day) was statistically significantly higher than in patients without a monoclonal component detected in blood serum (median 0.04 g/24h). The levels of FLC in blood serum obtained by immunoturbidimetry in Bence-Jones myeloma of the corresponding type were higher than the reference levels in 100% of cases. The median level of κ-FLC reached 4358 mg/l, λ-FLC - 2225 mg/l, which was statistically significantly higher than the control levels. The median concentrations of IgG, IgA and IgM in patients with Bence-Jones myeloma were statistically significantly lower than in the control group, while the medians of ß2-microglobulin and C-reactive protein were significantly higher than in the control. Our investigation showed high diagnostic efficiency of electrophoretic and immunoturbidimetric analysis of monoclonal secretion in patients with Bence-Jones MM, while FLC analysis demonstrated maximum sensitivity. Bence-Jones MM revealed biochemical signs of secondary immunodeficiency and general inflammatory syndrome.

The Influence of Deterioration of Kidney Function on the Diagnostic Power of Laboratory Parameters Used in the Prognostic Classification of AL Amyloidosis.

There is a possibility that renal dysfunction may potentially reduce the diagnostic power of the laboratory parameters Tn, NT-proBNP and sFLC levels, used in the current prognostic classification of AL amyloidosis and the diagnosis of heart involvement by amyloid. In this study, the impact of lowering the eGFR value on the usefulness of these parameters in the prognosis and diagnosis of the presence of amyloid in the myocardium was assessed in a group of 71 patients with newly diagnosed primary amyloidosis. The assessment of diagnostic power of laboratory parameters was performed on the entire study group, and in the ranges of eGFR ≥ 60 and < 60 mL/min/1.73 m2. It has been proven that, with a decrease in the eGFR value, the concentrations of NT-proBNP and the κ uninvolved light chains increase significantly (p < 0.001). To assess the diagnostic power of laboratory parameters used in the diagnosis of myocardial involvement in patients with AL amyloidosis, an ROC analysis was performed. The highest values of AUC were obtained for the NT-proBNP concentration (AUC = 0.906). The lowest values of the AUC and Youden's index were obtained for the dFLC values (AUC = 0.723), and involved κ FLC concentration (AUC = 0.613). For all compared parameters, the smallest values of the AUC were obtained for eGFR (<60 mL/min/1.73 m2). It seems that the most suitable cardiac parameter used in the prognostic classification of AL amyloidosis, independent of renal function, is TnI. It should be noted that a concentration of involved λ chains hada higher diagnostic power to assess the heart involvement, compared to the routinely used "cardiac parameters", TnI and NT-proBNP. It can therefore be an additional parameter used to assess the presence of amyloid in the myocardium. A decrease in eGFR value influenced the change in the diagnostic cut-off points of the most analyzed laboratory parameters. Finally, it is concluded that lowering the eGFR value reduces the utility of laboratory parameters used in the prognostic classification of AL amyloidosis.

CSF Free Light Chains as a Marker of Intrathecal Immunoglobulin Synthesis in Multiple Sclerosis: A Blood-CSF Barrier Related Evaluation in a Large Cohort.

Objectives: The importance of immunoglobulin G (IgG) oligoclonal bands (OCB) in the diagnosis of multiple sclerosis (MS) was reaffirmed again in the recently revised MS diagnostic criteria. Since OCB testing is based on non-quantitative techniques and demands considerable methodological experience, measurement of CSF immunoglobulin free light chains (FLC) has been suggested as quantitative alternative to OCB. We aimed to establish reference values for FLC measures and evaluate their diagnostic accuracy with regard to the diagnosis of MS. Methods: Immunoglobulin kappa (KFLC) and lambda (LFLC) free light chains were prospectively measured by nephelometry in CSF and serum sample pairs in 1,224 patients. The analyzed cohort included patients with MS, other autoimmune or infectious inflammatory diseases of the nervous system as well as 989 patients without signs for nervous system inflammation. Results: Regarding diagnosis of MS, the diagnostic sensitivity and specificity of intrathecal KFLC ratio were 93.3 and 93.7% using the CSF-serum albumin ratio-dependent reference values, 92.0 and 95.9% for intrathecal KFLC ratio applying the ROC-curve determined cut-off levels, 62.7 and 98.3% for IgG index, 64.0 and 98.8% for intrathecal IgG synthesis according to Reiber diagrams, and 94.7 and 93.3% for OCB. Diagnostic sensitivity and specificity of intrathecal LFLC were clearly lower than KFLC. Conclusions: Intrathecal KFLC and OCB showed the highest diagnostic sensitivities for MS. However, specificity was slightly lower compared to other quantitative IgG parameters. Consequently, CSF FLC may not replace OCB, but it may support diagnosis in MS as a quantitative parameter.

Immunoglobulin free light chains in saliva: a potential marker for disease activity in multiple sclerosis.

A new procedure was developed and applied to study immunoglobulin free light chains (FLC) in saliva of healthy subjects and patients with multiple sclerosis (MS). The procedure was based on a Western blot analysis for detection and semiquantitative evaluation of monomeric and dimeric FLCs. The FLC indices accounting for the total FLC levels and for the monomer/dimer ratios of κ and λ FLC were calculated, and the cut-off values of the FLC indices were determined to distinguish healthy state from MS disease. The obtained FLC index values were statistically different in the saliva of three groups: active MS patients, MS patients in remission and healthy subjects groups. Our FLC monomer-dimer analysis allowed differentiation between healthy state and active MS with specificity of 100% and a sensitivity of 88·5%. The developed technique may serve as a new non-invasive complementary tool to evaluate the disease state by differentiating active MS from remission with sensitivity of 89% and specificity of 80%.

Clinical Correlates and Prognostic Significance of IL-8, sIL-2R, and Immunoglobulin-Free Light Chain Levels in Patients with Myelofibrosis.

BACKGROUND: Chronic myeloproliferative neoplasms are characterized by clonal hematopoiesis and persistent inflammatory reaction. In this study, the clinical significance and prognostic impact of several inflammatory markers were evaluated in patients with BCR/ABL-negative myeloproliferative malignancies. METHODS: Serum levels of interleukin-8 (IL-8) and lymphoid-associated activation markers - soluble interleukin-2 receptor (sIL-2R) and immunoglobulin-free light chains (FLC) - were evaluated in patients with primary myelofibrosis (MF), post-polycythemia vera MF, and post-essential thrombocythemia MF, and compared with the levels in healthy donors. RESULTS: In 57 MF patients, sIL-2R excess correlated with transfusion-dependent anemia (p = 0.03) and splenomegaly (p = 0.02). There were no statistically significant correlations between sIL-2R and IL-8 levels, but the plasma concentration of κ-FLC positively correlated with the IL-8 level (p = 0.027). In univariate analysis, increased levels of IL-8 (p = 0.016) and sIL-2R (p = 0.010) significantly reduced 1-year overall survival. Only elevated sIL-2R rate retained significance (p = 0.02) in multivariate analysis when Dynamic International Prognostic Scoring System plus (DIPSSplus) risk stratification was added. CONCLUSION: We observed an association between FLC and proinflammatory cytokine hyperexpression. Serum cytokine levels and FLC might be a promising approach to predicting and monitoring treatment response in MF patients.

[Diagnostic value of immunoglobulin free light chains at the debut of multiple sclerosis]. / Rol' opredeleniia svobodnykh legkikh tsepei immunoglobulinov v diagnostike debiuta rasseiannogo skleroza.

AIM: To evaluate the diagnostic value of determination of free immunoglobulin light chains (IgG) in the debut of multiple sclerosis (MS). MATERIAL AND METHODS: Data from 226 patients, including 111 patients with clinically isolated syndrome with conversion to multiple sclerosis within the first 2 years of the disease (group 1), 49 patients with clinically isolated syndrome who did not develop multiple sclerosis within the first 2 years of the disease (group 2), 20 patients with other inflammatory diseases of the central nervous system (group 3) were analyzed. The control group consisted of 46 patients with non-inflammatory diseases of the central nervous system. The clonality of immunoglobulins in the CSF, concentration of kappa and lambda free light chains and their ratio were studied. RESULTS: Concentrations of free light chains were significantly higher in the first group in comparison with group 2 and the control group, but didn't differ from group 3. In group 3, concentrations of free light chains were significantly higher compared to group 2 and controls. In oligoclonal-positive patients with clinically isolated syndrome (groups 1 and 2), concentrations of kappa and lambda free light chains were significantly higher than in oligoclonal-negative patients. The production of free light chains in patients from the first group was considerably higher than in group 2 regardless of the oligoclonal status. The concentration of kappa chains and quotient of kappa free light chains in the CSF had the best diagnostic characteristics. Their use, along with the evaluation of IgG clonality, reduced the risk of false-negative results by 50%. Regardless of other factors, elevated concentrations of kappa chains increase the likelihood of MS diagnosis by 9.718 times. CONCLUSION: The use of free light chains as a laboratory marker can increase the accuracy of MS diagnosis. These markers can help indirectly assess the risk of transformation of a clinically isolated syndrome into definite multiple sclerosis within the first 2 years of disease.

[The association of intrathecal production of immunoglobulin free light chains and progression of multiple sclerosis]. / Sviaz' intratekal'noi produktsii svobodnykh legkikh tsepei immunoglobulinov s progressirovaniem rasseiannogo skleroza.

AIM: To assess an impact of immunoglobulin free light chains (FLC) on short-term and long-term prognosis of clinical and radiological activity and progression of disability in multiple sclerosis (MS). MATERIAL AND METHODS: A sample of 381 patients with definite MS was divided into 2 groups. In group 1, lumbar puncture was performed at the time of clinically isolated syndrome, and patients were prospectively followed up to 2 years (short-term prognosis group, n=97). In group 2, MS was diagnosed immediately after lumbar puncture, and retrospective analysis of the disease course with the duration not less than 5 years was performed (long-term prognosis group, n=284). The Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Severity Score (MSSS) were used to assess patient's status. Concentrations of kappa and lambda FLC in the CSF (K-FLCCSF, L-FLCCSF) and serum (K-FLCSERUM, L-FLCSERUM) as well as quotients of concentrations (Q-K and Q-L) were determined. Patients were stratified into subgroups with high and low concentrations of K-FLC and L-FLC using cut-offs from our previous studies: K-FLCCSF=0.595 mcg/l and L-FLCCSF=0.127 mcg/l. RESULTS: In group 1, significant correlations were found only between EDSS score and concentrations of K-FLCCSF (r=0.377, p=0.00019) and Q-K (r=0.366, p=0.0012). FLC concentrations did not correlate with the number of relapses and new T2 lesions. The age and EDSS score at the disease onset didn't differ between patients with high and low K-FLC and L-FLC (K-FLCCSF: р=0.2658; L-FLCCSF: р=0.5502). A significant decrease of EDSS score after the disease onset was observed in all groups except for patients with high concentrations of K-FLCCSF (p=0.1844), so the EDSS score after 2 years was significantly higher in this subgroup of patients (p=0.0006). In group 2, significant correlations of K-FLC with EDSS score (r=0.181, p=0.002) and MSSS score (r=0.121, р=0.044) for long-term prognosis (median (IQR) = 8 (6-13) years) were found. No correlations of FLC concentrations with the number of relapses during the first 5 years were found. Survival analysis showed that high concentrations of K-FLCCSF were associated with the high risk of progression to EDSS 6 (HR=2.055, p=0.026) but not with EDSS 4 (HR=2.388, p=0.08). CONCLUSION: Concentrations of kappa FLC can help to define the prognosis of MS early at the disease course. Although low concentrations of FLC do not exclude a severe disease phenotype, patients with high K-FLCCSF concentrations are at greater risk for faster MS progression, probably, due to impaired reparation of neural tissue. Measurement of FLC concentrations can be used to determine a therapeutic tactics in patients with MS.

Paraprotein-Related Kidney Disease: Kidney Injury from Paraproteins-What Determines the Site of Injury?

Disorders of plasma and B cells leading to paraproteinemias are associated with a variety of renal diseases. Understanding the mechanisms of injury and associated nephropathies provides a framework that aids clinicians in prompt diagnosis and appropriate adjunctive treatment of these disorders. Glomerular diseases that may be associated with paraproteinemias include amyloid deposition, monoclonal Ig deposition disease, proliferative GN with monoclonal Ig deposits, C3 glomerulopathy caused by alterations in the complement pathway, immunotactoid glomerulopathy, fibrillary GN, and cryoglobulinemia. Tubular lesions include the classic Fanconi syndrome, light-chain proximal tubulopathy, interstitial fibrosis, and cast nephropathy. These paraproteinemic renal diseases are distinct in their pathogenesis as well as their urinary and kidney biopsy findings. Renal pathology is usually initiated by deposition and direct involvement of the intact monoclonal Ig or Ig fragments with resident cells of the nephron. Our review summarizes current insights into the underlying molecular pathogenesis of these interesting kidney lesions.

Improving strategies for the diagnosis of cardiac amyloidosis.

Amyloidosis refers to a group of rare but potentially fatal, protein misfolding diseases. The heart is frequently involved in the most common types, that is, immunoglobulin light chain and transthyretin amyloidosis and is the single most important predictor of patient outcomes. A major limitation in improving patient outcomes, in addition to developing novel therapeutics, is the late diagnosis of the disease. Once suspected, an organ for biopsy should be targeted and the amyloid type should be identified by mass spectrometry. An endomyocardial biopsy should be offered if cardiac involvement is in doubt. Echocardiography, MRI and nuclear imaging can provide valuable diagnostic and prognostic information and can secure the diagnosis if amyloid has been identified in an extracardiac tissue.

Free kappa light chains in cerebrospinal fluid as a biomarker to assess risk conversion to multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) initiates with a first attack or clinically isolated syndrome (CIS). The importance of an early treatment in MS leads to the search, as soon as possible, for novel biomarkers which can predict conversion from CIS to MS. OBJECTIVE: The purpose of this study was to assess the predictive value of the kappa index ([Formula: see text] index), using kappa free light light chains ([Formula: see text]FLCs) in cerebrospinal fluid (CSF), for the conversion of CIS patients to MS, and compare its accuracy with other parameters used in clinical practice. METHODS: FLC levels were analysed in CSF from 176 patients: 70 as control group, 77 CIS, and 29 relapsing-remitting MS. FLC levels were quantified by nephelometry. RESULTS: [Formula: see text] Index sensitivity and specificity (93.1%; 95.7%) was higher than those from the immunoglobulin G (IgG) index (75.9%; 94.3%), and lower than those from oligoclonal IgG bands (OCGBs) (96.5%; 98.6%). The optimal cut-off for [Formula: see text] index was 10.62. Most of the CIS patients with [Formula: see text] index >10.62 presented OCGBs, IgG index >0.56 and fulfilled magnetic resonance imaging (MRI) criteria. CONCLUSION: CIS patients above [Formula: see text] index cut-off of 10.62 present 7.34-fold risk of conversion to MS than CIS below this value. The [Formula: see text] index correlated with positive OCGBs, IgG index above 0.56 and MRI criteria.

[AL amyloidosis]. / Amylose AL.

AL amyloidosis belongs to the group of conformational diseases. It is the most common type of amyloidosis with an estimated 500 new cases per year in France. It is due to a small and usually indolent plasma cell clone which synthesizes an unstable, misfolded monoclonal immunoglobulin light chain that is prone to aggregate and form amyloid fibrils. Non-invasive biopsy such as abdominal fat aspiration or minor salivary gland biopsy should be performed to confirm the diagnosis and if negative, involved tissues have to be examined. Clinical presentation is very diverse, as AL amyloidosis can affect almost any organ or tissue in the body, other than the brain. The kidney is the most frequent organ involved, whereas heart disease characterized by restrictive cardiomyopathy is the most severe. Early diagnosis, before advanced cardiomyopathy, is essential for improving outcome. The association of alkylating agent and high-dose dexamethasone is effective in almost two-thirds of patients. Combinations of proteasome inhibitors, dexamethasone, and alkylating agents achieve high response rates. Close monitoring of clonal and organ response is mandatory to guide therapy changes and duration. New treatments designed to eliminate amyloid deposits are under development.

Serum immunoglobulin free light chain levels are higher in girls than boys during eosinophilic oesophagitis.

AIM: Eosinophilic oesophagitis (EO) is an emerging worldwide disease, closely associated with male gender and allergic disorders. This study investigated the distribution of allergy markers in a cohort of children with EO. METHODS: We analysed allergy markers in 91 children (62 males and 29 females) with EO and a control group of 45 age-matched children who had non-EO gastrointestinal allergic symptoms. The markers analysed were serum cow's milk-specific and hen's egg-specific IgE, thymic stromal lymphopoietin (TSLP), thymus-regulated and activation-regulated chemokine (TARC/CCL17) and immunoglobulin free light chain (Ig-fLC). RESULTS: In the EO group, cow's milk-specific IgE levels were detectable in 41.9% of males and 62.1% of females and hen's egg-specific levels in 25% of males and 26.9% of females. There was no gender difference in increased TSLP or TARC levels. Kappa Ig-fLC were increased in 5.6% of males and 20.8% of females (p = 0.058) and lambda Ig-fLC in 1.9% of males and 33.3% of females (p = 0.000). No gender differences were found in the control group. CONCLUSION: Our findings suggest that serum TSLP might be a potential marker of EO and TARC of non-EO gastrointestinal food allergies. In EO, serum Ig-fLC appeared higher in females, adding another gender difference to the biology of EO.