NLRP3 Inflammasome Involvement in Heart, Liver, and Lung Diseases-A Lesson from Cytokine Storm Syndrome

Inflammation and inflammasomes have been proposed as important regulators of the host-microorganism interaction, playing a key role in morbidity and mortality due to the coronavirus disease 2019 (COVID-19) in subjects with chronic conditions and compromised immune system. The inflammasome consists of a multiprotein complex that finely regulates the activation of caspase-1 and the production and secretion of potent pro-inflammatory cytokines such as IL-1β and IL-18. The pyrin containing NOD (nucleotide-binding oligomerization domain) like receptor (NLRP) is a family of intracellular receptors, sensing patterns associated to pathogens or danger signals and NLRP3 inflammasome is the most deeply analyzed for its involvement in the innate and adaptive immune system as well as its contribution to several autoinflammatory and autoimmune diseases. It is highly expressed in leukocytes and up-regulated in sentinel cells upon inflammatory stimuli. NLRP3 expression has also been reported in B and T lymphocytes, in epithelial cells of oral and genital mucosa, in specific parenchymal cells as cardiomyocytes, and keratinocytes, and chondrocytes. It is well known that a dysregulated activation of the inflammasome is involved in the pathogenesis of different disorders that share the common red line of inflammation in their pathogenetic fingerprint. Here, we review the potential roles of the NLRP3 inflammasome in cardiovascular events, liver damage, pulmonary diseases, and in that wide range of systemic inflammatory syndromes named as a cytokine storm.

Type 2 cytokines and scleroderma interstitial lung disease

Interstitial lung disease (ILD) is a life-threatening complication of systemic sclerosis (SSc). Type 2 (Th2) cytokines play a pivotal role in airway disease. Study aim was to evaluate serum level of Th2 interleukin (IL) and chemokine in SSc-ILD. Serum levels of IL-4, IL-5, IL-11, IL-13, IL-21, IL-31 and CXCL-13 were measured by Bio-Plex Multiplex Immunoassays in 60 SSc patients and 20 healthy controls (HC). Pulmonary function tests with diffusion lung capacity for carbon monoxide (DLco) and high resolution computed tomography (HRCT) were performed in SSc patients. ILD is defined as fibrotic changes (ground glass, reticular and honeycombing), assessed by Computer-Aided Lung Informatics for Pathology Evaluation and Ratings (CALIPER) software, affecting at least 10% of the lungs. Serum levels of Th2 cytokines were higher in SSc patients than HC. A linear correlation was observed between ground glass and IL-13 (r = 0.342, p < 0.01), IL-21 (r = 0.345, p < 0.01), IL-31 (r = 0.473, p < 0.001), IL-4 (r = 0.863, p < 0.001), IL-5 (r = 0.249, p < 0.05) and peripheral blood eosinophils (r = 0.463, p < 0.001). We found a negative correlation between DLco and IL-4 (r =  - 0.511, p < 0.001) and peripheral blood eosinophils (r =  - 0.446, p < 0.001). In the logistic regression analysis, IL-4 is associated with DLco ≤ 60% of the predicted [OR 1.039 (CI 95%: 1.015-1.064), p < 0.001], whilst mRSS [OR 1.138 (CI 95%: 1.023-1.266), p < 0.05] and IL-4 [OR 1.017 (CI 95%: 1-1.034), p < 0.05] were associated with ILD. Th2 inflammation could play a key role in early phase of SSc-ILD.

Serological and Molecular Characterization of Hepatitis C Virus-Related Cryoglobulinemic Vasculitis in Patients without Cryoprecipitate

Prolonged B cells stimulation due to the Hepatitis C virus (HCV) can result in autoimmunity, stigmatized by rising levels of cryoglobulins (CGs), the rheumatoid factor (RF), and free light chains (FLC) of immunoglobulins (Ig) associated with a range of symptoms, from their absence to severe cryoglobulinemic vasculitis and lymphoma. Here, we aimed to identify an immunological signature for the earliest stages of vasculitis when cryoprecipitate is still not detectable. We firstly analyzed the IgG subclasses, FLC, and RF in 120 HCV-RNA-positive patients divided into four groups according to the type of cryoprecipitate and symptoms: 30 asymptomatic without cryoprecipitate (No Cryo), 30 with vasculitis symptoms but without CGs that we supposed were circulating but still not detectable (Circulating), 30 type II and 30 type III mixed cryoglobulinemia (Cryo II and Cryo III, respectively). Our results revealed that patients with supposed circulating CGs displayed a pattern of serological parameters that closely resembled Cryo II and Cryo III, with a stronger similarity to Cryo II. Accordingly, we analyzed the groups of Circulating and Cryo II for their immunoglobulin heavy chain (IgH) and T-cell receptor (TCR) gene rearrangements, finding a similar mixed distribution of monoclonal, oligoclonal, and polyclonal responses compared to a control group of ten HCV-RNA-negative patients recovered from infection, who displayed a 100% polyclonal response. Our results strengthened the hypothesis that circulating CGs are the origin of symptoms in HCV-RNA-positive patients without cryoprecipitate and demonstrated that an analysis of clonal IGH and TCR rearrangements is the best option for the early diagnosis of extrahepatic complications.

Elevated serum polyclonal immunoglobulin free light chains in patients with severe asthma

Background: Inflammation plays a pivotal role in the pathophysiology of asthma. Free light chains (FLC) can cause inflammation by mast cell antigen-activation. Serum immunoglobulin (Ig) FLC κ, but not λ, were shown elevated in adult males with asthma. We sought to investigate if serum Ig FLC concentrations are affected by asthma severity and their relationships with inflammatory outcomes. Methods: By using immunoassays, we measured serum κ and λ Ig FLCs in 24 severe persistent asthma patients, 15 patients with moderate persistent asthma, 15 steroid-naïve mild persistent asthma patients and 20 healthy control subjects in a cross-sectional observational study. Total and specific serum IgE concentrations, fractional exhaled nitric oxide (F_ENO), lung function, peripheral blood eosinophils and neutrophils, and C reactive protein (CRP) were also measured. Results: Serum κ FLC concentrations were elevated in severe asthma patients compared mild asthma patients (p < 0.05) and healthy subjects (p < 0.05). Serum λ FLCs were higher in severe asthma patients than in healthy subjects (p < 0.05) and correlated with blood eosinophil counts (percentage, κ: r = 0.51, p = 2.9678^-6; λ: r = 0.42, p = 1.7377^-4; absolute values, κ: r = 0.45, p = 6.1284^-5; λ: r = 0.38, p = 7.8261^-4), but not with total or specific serum IgE. In severe asthma patients, serum Ig FLC correlated with serum CRP (κ: r = 0.33; p = 0.003; λ: r = 0.38, p = 8.8305^-4) and blood neutrophil cell counts (percentage, κ: r = 0.31; p = 0.008; λ: r = 0.29, p = 0.01; absolute values, κ: r = 0.40; p = 3.9176^-4; λ: r = 0.40, p = 4.5479^-4), were elevated in subjects with blood eosinophilia (≥300 cells/µL) (n = 13) compared with non-eosinophilic subjects (n = 10) (κ: 19.2 ± 1.2 mg/L versus 12.1 ± 1.3 mg/L, p < 0.001; λ: 27.2 ± 2.6 mg/L versus 16.8 ± 2.5 mg/L, p < 0.01), but were similar in atopic (n = 15) versus nonatopic subjects (n = 9) (κ: p = 0.20; λ: p = 0.80). Serum FLC were negatively correlated with lung function tests, including forced expiratory volume in one second (FEV1) (κ: r = -0.33; p = 0.0034; λ: r = -0.33; p = 0.0035), and FEV₁/forced vital capacity ratio (κ: r = -0.33; p = 0.0034; λ: r = -0.33; p = 0.0036). Conclusion: Serum Ig FLCs are elevated in severe asthma adults and might represent new surrogate markers of inflammation. The pathophysiological implications of these findings require further research. This study was approved by the ethics committee of the University Hospital Agostino Gemelli Foundation and Catholic University of the Sacred Heart (approval number P/1034/CE2012).

The dark side of current analytic methods for Bence Jones Proteinuria

OBJECTIVE

Bence Jones proteinuria (BJP) refers to monoclonal free immunoglobulin light chains detected in urine, deriving from the clonal expansion of plasma cells in the bone marrow in patients with plasma cell dyscrasias, associated with monoclonal gammopathies of uncertain origin. This review summarizes routinely diagnostic procedures to assess BJP highlighting critical steps of pre-analytical, analytical, and post-analytical phases.

QUALITATIVE AND QUANTITATIVE METHODS

The best option for BJP detection is the first morning void urine sample and immunofixation electrophoresis detection technique (IFE) the recommended method, with the employment of specific polyvalent antisera. Other qualitative tests for a quick evaluation of BJP are currently available. Densitometric analysis performed on the 24-hour urine is the recommended method to quantify BJP. To overcome the 24-hour collection, it is possible to use morning urine sample and correlate the assessed value of BJP to creatininuria. In addition to the traditional ones, we here reviewed screening methods currently used to avoid false negatives and reduce the time around test (TAT), together with immunochemical quantification methods for increased sensitivity, after checking BJP by IFE. Mass spectrometry emerges as a new challenge in the determination of BJP.

CONCLUSIONS

The employment of different based-assays methods may be useful for diagnostic purposes to improve the accuracy of BJP monitoring in monoclonal gammopathies.

Mono/polyclonal free light chains as challenging biomarkers for immunological abnormalities

Free light chain (FLC) kappa (k) and lambda (λ) consist of low molecular weight proteins produced in excess during immunoglobulin synthesis and secreted into the circulation. In patients with normal renal function, over 99% of FLCs are filtered and reabsorbed. Thus, the presence of FLCs in the serum is directly related to plasma cell activity and the balance between production and renal clearance. FLCs are bioactive molecules that may exist as monoclonal (m) and polyclonal (p) FLCs. These have been detected in several body fluids and may be key indicators of ongoing damage and/or illness. International guidelines now recommend mFLC for screening, diagnosis and monitoring multiple myeloma and other plasma cell dyscrasias. In current clinical practice, FLCs in urine indicate cast nephropathy and other renal injury, whereas their presence in cerebrospinal fluid is important for identifying central nervous system inflammatory diseases such as multiple sclerosis. Increased pFLCs have also been detected in various conditions characterized by B cell activation, i.e., chronic inflammation, autoimmune disease and HCV infection. Monitoring the coronavirus (COVID-19) pandemic by analysis of salivary FLCs presents a significant opportunity in clinical immunology worthy of scientific pursuit.

A Comparative Study of Serum Angiogenic Biomarkers in Cirrhosis and Hepatocellular Carcinoma

Simple Summary

The progression of liver disease is accompanied by pathological angiogenesis, a prerequisite for the development of HCC. In this paper, we analyzed the clinical significance of serum angiogenic markers VEGF, Ang-1, Ang-2, angiopoietin receptor Tie1/2, HGF, and PECAM-1 in 62 patients with liver disease, out of which 33 were diagnosed with HCC and 29 with liver cirrhosis without signs of neoplasia. Biomarkers levels were investigated as a function of “Model for End-Stage Liver Disease” (MELD) score and Fibrosis Index (FI). HCC patients showed higher HGF levels than ones with cirrhosis, while high Ang-1 levels appeared to have a protective role in HCC as well as prognostic significance; we also found a strong correlation between HGF levels, Ang-2, and VEGF levels, further supporting their role in tumor angiogenesis. Due to the complexity of angiogenesis and the small size of the study group, further investigations are widely desired especially in the era of immunotherapy and HCC-targeted anti-angiogenic drugs.

Abstract

Background: Hepatocellular carcinoma (HCC) is a global health problem associated with chronic liver disease. Its pathogenesis varies according to the underlying etiological factors, although in most cases it develops from liver cirrhosis. The disease progression is accompanied by pathological angiogenesis, which is a prerequisite that favors the development of HCC. Aims: This study aims at contributing to our understanding of the role of angiogenic factors in the progression of liver disease. For this purpose, we evaluate the clinical significance of serum angiogenic markers (VEGF, Ang-1, Ang-2, the angiopoietin receptor Tie1/2, HGF, and PECAM-1) first in cirrhotic and HCC patients separately, and then comparing cirrhotic patients with and without HCC. Materials and Methods: We enrolled 62 patients, out of whom 33 were diagnosed with HCC and 29 with liver cirrhosis without signs of neoplasia. Patients underwent venous blood sampling before and after receiving treatments for the diagnosed disease. Serum markers were evaluated using ELISA assays for Tie1 and the Bio-Plex Multiplex system for the remaining ones. Biomarker levels were investigated as a function of clinical scores for disease staging (MELD and Fibrosis Index, FI). Results: In cirrhotic patients, Ang-1 and Ang-2 correlate with MELD (ρ_Ang-1 = −0.73, p = 2E−5) and FI (ρ_Ang-1 = −0.52, p = 7E−3, ρ_Ang-2 = 0.53, p = 3E−3). A reduction of Ang-2 levels (p = 0.047) and of the Ang-2/Ang-1 ratio (p = 0.031) is observed in cirrhotic patients diagnosed with viral hepatitis after antiviral treatments. In HCC patients, Ang-1 negatively correlates with FI (ρ = −0.63, p = 1E−4), and PECAM-1 positively correlates with MELD (ρ = 0.44, p = 0.01). A significant Ang-1 reduction was observed in deceased patients during the study compared to ones who survived (p = 0.01). In HCC patients, VEGF levels were increased after tumor treatment (p = 0.037). Notably, HGF levels in cirrhotic patients with HCC are significantly raised (p = 0.017) compared to that in those without HCC. Conclusions: Our results suggest that serum angiogenic markers, with emphasis on Ang-1/2, can contribute to the development of quantitative tools for liver disease staging and therapy monitoring. The comparison between cirrhotic patients with and without HCC suggests that HGF levels are potentially useful for monitoring the insurgence of HCC after a cirrhosis diagnosis. High Ang-1 levels in HCC patients appear to have a protective role as well as prognostic significance.

COVID-19, adaptative immune response and metabolic-associated liver disease

Metabolic diseases are associated with a higher risk of a severer coronavirus disease 2019 (COVID-19) course, since fatty liver is commonly associated with metabolic disorders, fatty liver itself is considered as a major contributor to low-grade inflammation in obesity and diabetes. Recently a comprehensive term, metabolic (dysfunction) associated fatty liver disease (MAFLD), has been proposed. The hepatic inflammatory status observed in MAFLD patients is amplified in presence of severe acute respiratory syndrome coronavirus 2 infection. Intestinal dysbiosis is a powerful activator of inflammatory mediator production of liver macrophages. The intestinal microbiome plays a key role in MAFLD progression, which results in non-alcoholic steatohepatitis and liver fibrosis. Therefore, patients with metabolic disorders and COVID-19 can have a worse outcome of COVID-19. This literature review attempts to disentangle the mechanistic link of MAFLD from COVID-19 complexity and to improve knowledge on its pathophysiology.

SMA-miRs (miR-181a-5p, -324-5p, and -451a) are overexpressed in spinal muscular atrophy skeletal muscle and serum samples

Background:

Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by the degeneration of the second motor neuron. The phenotype ranges from very severe to very mild forms. All patients have the homozygous loss of the SMN1 gene and a variable number of SMN2 (generally 2–4 copies), inversely related to the severity. The amazing results of the available treatments have made compelling the need of prognostic biomarkers to predict the progression trajectories of patients. Besides the SMN2 products, few other biomarkers have been evaluated so far, including some miRs.

Methods:

We performed whole miRNome analysis of muscle samples of patients and controls (14 biopsies and 9 cultures). The levels of muscle differentially expressed miRs were evaluated in serum samples (51 patients and 37 controls) and integrated with SMN2 copies, SMN2 full-length transcript levels in blood and age (SMA-score).

Results:

Over 100 miRs were differentially expressed in SMA muscle; 3 of them (hsa-miR-181a-5p, -324-5p, -451a; SMA-miRs) were significantly upregulated in the serum of patients. The severity predicted by the SMA-score was related to that of the clinical classification at a correlation coefficient of 0.87 (p<10^-5).

Conclusions:

miRNome analyses suggest the primary involvement of skeletal muscle in SMA pathogenesis. The SMA-miRs are likely actively released in the blood flow; their function and target cells require to be elucidated. The accuracy of the SMA-score needs to be verified in replicative studies: if confirmed, its use could be crucial for the routine prognostic assessment, also in presymptomatic patients.

Funding:

Telethon Italia (grant #GGP12116).

Solving the mystery of HBV-related mixed cryoglobulinemia: potential biomarkers of disease progression

OBJECTIVES

The biomarkers of an immunological dysregulation due to a chronic HBV infection are indeed understudied. If untreated, this condition may evolve into liver impairment co-occurring with extrahepatic involvements. Here, we aim to identify a new panel of biomarkers [including immunoglobulin G (IgG) subclasses, RF, and Free Light Chains (FLCs)] that may be useful and reliable for clinical evaluation of HBV-related cryoglobulinemia.

METHODS

We retrospectively analysed clinical data from 44 HBV-positive patients. The patients were stratified (according to the presence/absence of mixed cryoglobulinemia) into two groups: 22 with cryoglobulins (CGs) and 22 without CGs. Samples from 20 healthy blood donors (HDs) were used as negative controls. Serum samples were tested for IgG subclasses, RF (-IgM, -IgG, and -IgA type), and FLCs.

RESULTS

We detected a strikingly different distribution of serum IgG subclasses between HDs and HBV-positive patients, together with different RF isotypes; in addition, FLCs were significantly increased in HBV-positive patients compared with HDs, while no significant difference was shown between HBV-positive patients with/without mixed cryoglobulinemia.

CONCLUSION

The immune-inflammatory response triggered by HBV may be monitored by a peculiar profile of biomarkers. Our results open a new perspective in the precision medicine era; in these challenging times, they could also be employed to monitor the clinical course of those COVID-19 patients who are at high risk of HBV reactivation due to liver impairment and/or immunosuppressive therapies.

Laboratory Investigation of Hybrid IgG4 k/λ in MuSK Positive Myasthenia Gravis

Myasthenia gravis with antibodies (Abs) against the muscle-specific tyrosine kinase (MuSK) is a rare autoimmune disorder (AD) of the neuromuscular junction (NMJ) and represents a prototype of AD with proven IgG4-mediated pathogenicity. Thanks to the mechanism of Fab-arm exchange (FAE) occurring in vivo, resulting MuSK IgG4 k/λ Abs increase their interference on NMJ and pathogenicity. The characterization of hybrid MuSK IgG4 as a biomarker for MG management is poorly investigated. Here, we evaluated total IgG4, hybrid IgG4 k/λ, and the hybrid/total ratio in 14 MuSK-MG sera in comparison with 24 from MG with Abs against acetylcholine receptor (AChR) that represents the not IgG4-mediated MG form. In both subtypes of MG, we found that the hybrid/total ratio reflects distribution reported in normal individuals; instead, when we correlated the hybrid/total ratio with specific immune-reactivity we found a positive correlation only with anti-MuSK titer, with a progressive increase of hybrid/total mean values with increasing disease severity, indirectly confirming that most part of hybrid IgG4 molecules are engaged in the anti-MuSK pathogenetic immune-reactivity. Further analysis is necessary to strengthen the significance of this less unknown biomarker, but we retain it is full of a diagnostic-prognostic powerful potential for the management of MuSK-MG.

The diagnostic performance of PIVKA-II in metabolic and viral hepatocellular carcinoma: a pilot study

OBJECTIVE

Hepatocellular carcinoma (HCC) is a primary liver tumor derived from metabolic or viral chronic hepatitis, with few treatment options in advanced cases. New biomarkers that allow improving diagnosis and staging are widely desired. Here, we aim to evaluate the performance of Protein Induced by Vitamin K Absence or Antagonist-II (PIVKA-II) in combination with α-fetoprotein (AFP), in the diagnosis of HCC in patients with metabolic or viral hepatitis.

PATIENTS AND METHODS

We enrolled 60 HCC patients (20 metabolic and 40 viral) and 20 healthy subjects (HS) as negative controls. PIVKA-II, AFP, Matrix metalloproteinase-9 (MMP-9) and Fibroblast growth factor (FGF) serum levels were assessed by immunoassays.

RESULTS

AFP and PIVKA-II levels were obviously higher in patients than in HS. AFP displayed a better diagnostic performance than PIVKA-II for viral HCC while PIVKA-II was better for metabolic HCC. The combination of the two biomarkers did not improve the discriminating ability.

CONCLUSIONS

PIVKA-II may be considered an independent predictor of macrovascular invasion from HCC cells and it can be used to better stratify HCC patients and should be evaluated in prospective studies for early detection of advanced HCC in metabolic subjects.

Evaluation of Free Light Chains of Immunoglobulins in Seminal Plasma of Infertile Patients: Preliminary Data

Seminal plasma is a complex fluid with various components (proteins, enzymes, macro-and microelements, lipids and nutrients) and its role is fundamental for spermatozoa motility, viability and fertilizing capacity maintenance. Many molecules have been measured in seminal plasma to explore some secretion functions of male accessory glands, but effects of biochemical components in human seminal plasma are still debated. Immunoglobulin-free light chains (FLCs) κ and λ are produced by plasma cells in slight excess for the need of immune response and are therefore assayable in blood and in other biological fluids, such as urine, saliva, liquor and synovial fluid. Recently, different biological functions have been attributed to these molecules, suggesting that they are not just a secondary product of immunoglobulin synthesis. No data are reported about presence of FLCs in seminal plasma and their role in physiology of male reproductive system and/or in pathophysiology of infertility. The aims of our study were to investigate the presence and detectability of FLCs in seminal plasma and to evaluate the usefulness of this assay in the diagnostic approach to infertility patients. We enrolled 32 patients aged 19-40 ys, affected by primary infertility; among them, 7 were normospermic (mean±SEM concentration 100.0±16.0 *10⁶/ml; progressive motile forms 39.1±4.9%; normal forms 45.3±4.5%), 25 were oligo- and/or asthenoteratospermic (mean±SEM concentration 23.8±5.4*10⁶/ml; progressive motile forms 19.3±4.1%; normal forms 36.05±2.7%); moreover, 17 patients presented II-IV degree varicocele (VAR) according to Dubin-Amelar classification by Doppler technique, the remaining 15 patients did not present varicocele (NO-VAR). After abstinence for 3-5 days, semen samples were collected. FLCs concentrations were assayed by turbidimetric method. Standard semen analysis was performed according to WHO laboratory manual for the examination and processing of human semen, fifth edition, 2010. As main results, independently from sperm count, a significantly difference was observed concerning FLCs concentrations, with higher levels of k and k/λ ratio in NO-VAR vs VAR patients (mean±SEM k 36.4±13.2 vs 17.7±9.0 g/l and 7.7±2.9 vs 2.65±0.7, respectively; p<0.05). λ FLCs did not significantly differ between the two groups. This work shows for the first time that FLCs are assayable in seminal plasma, even if their source is to be determined (plasma filtration or local synthesis from lymphoid tissue in accessory gland). Our preliminary data also showed a peculiar pattern with prevalence of k FLCs in infertile patients without VAR, suggesting that FLCs could be in interesting field of investigation in idiopathic infertility. Further studies in large and stratified patients may reveal a possible usefulness of FLCs as a biological marker and/or gain insight about their etiopathogenetic role in male infertility.

Cryoglobulins: putative effectors of adaptive immune response

Cryoglobulinaemia consists of circulating monoclonal and/or polyclonal immunoglobulins with rheumatoid factor (RF) activity that precipitate at temperatures <37°C. Cryoglobulinaemic syndrome, characterised by clinical signs of systemic vasculitis, is associated with chronic infection of hepatitis C virus (HCV) and might evolve in B-cell malignancies. In about one third of all HCV infection cases, serum autoantibodies are commonly found. This is probably due directly to the transformation of infected B cells but, also, indirectly, to the viral chronic stimulation of a pool of autoreactive B cells. The pattern of IgG subclasses seems to contribute to the worsening progression of HCV infection into lymphoproliferative and/or autoimmune diseases. Many evidences showed that B cells circulating in patients with HCV-associated mixed cryoglobulinaemia (MC) are profoundly abnormal; moreover, in most of cases, normal B cells are replaced by expanded clonal B cells characterized by the low expression of CD21. After viral eradication, these cells persist in circulation and their occurrence does not correlate with serum cryoglobulins nor with vasculitis response or relapse. It is probably due to the persistence of monoclonal B cells producing RF, that in course of MC can be reactivated by circulating immune complexes, highly produced during infections or tumours. Here, we aimed to review current literature focusing the pathogenesis of MC referring to specificity and immunochemical characteristics of the immunoglobulins involved in cryoprecipitation.

Lack of association between Vitamin D status and free light chains profile with different chronic HCV-related liver and extrahepatic disorders

OBJECTIVE

A still uncertain association between vitamin D levels and HCV chronic liver diseases has been reported. Increased levels of serum-free light chains (FLCs) and an altered k/λ FLC ratio correlate with Mixed Cryoglobulinemia (MC) vasculitis and/or B-cell non-Hodgkin's lymphoma in HCV-positive patients. We aimed to investigate the possible role of vitamin D, vitamin D Binding Protein (DBP), and FLCs levels as a tool for discriminating different stages of HCV- related MC and chronic liver diseases.

PATIENTS AND METHODS

Sixty-five untreated patients were retrospectively enrolled and 21 healthy blood donors (HBD) were used as controls. Vitamin D, DBP, FLCs, and cryoglobulins levels were measured. Based on cryoglobulins, patients were divided in three subgroups (without cryoglobulins, type II, and type III).

RESULTS

We didn't find any significant differences in vitamin D and DBP levels between HCV patients' main groups and HBD. Serum FLCs levels were significantly higher in HCV patients than in HBD. FLCs ratio among patients' subgroups did not reveal differences.

CONCLUSIONS

Our results confirm the presence of an increased serum level of FLCs in HCV patients and suggest that nor vitamin D and DBP or FLC levels can be considered reliable biomarkers for discriminating different stages of HCV-associated chronic liver diseases and/or HCV-associated extrahepatic manifestation. We confirm that serological FLCs levels are significantly higher in patients than in HBD as a signature of B cell activation in course of HCV infection.

Fecal calprotectin and need of multiple microbiota trasplantation infusions in Clostridium difficile infection

BACKGROUND AND AIM

Fecal microbiota transplantation (FMT) has proven to be very effective in recurrent Clostridium difficile infection (CDI) when compared with standard antibiotic therapy. However, given the lack of validated criteria, decision regarding number and timing of infusions is currently based on the clinician's experience, severity of infection, and clinical response. We performed a longitudinal assessment of fecal calprotectin concentration (FCC) in CDI patients undergoing FMT. FCCs were correlated with the need for multiple infusions and with the clinical status of the patient.

METHODS

Fecal calprotectin concentration measurement was performed just before first procedure (T₀ ) and 2 (T₁ ) and 5 (T₂ ) days later. The need for reinfusion was accounted for in the 8 weeks following procedure, and clinical status was evaluated at the end of the given period. Both outcomes were correlated with measured FCCs.

RESULTS

A total of 28 CDI patients undergoing FMT were enrolled. Median FCCs at T₀ were significantly higher in patients who needed repeat FMT, 540 μg/g versus patients who underwent single FMT, 290 μg/g (P < 0.05). Differences were not significant for FCC at T₁ and T₂ . Regarding correlation with clinical outcome, median FCC at T₀ was found to be lower in responders compared with non-responders with a trend towards statistical significance (P = 0.07). Correlation at T₁ and T₂ was not significant.

CONCLUSIONS

The use of an easily obtainable parameter such as fecal calprotectin could possibly optimize overall management of FMT procedural framework potentially being able to immediately identify patients who may benefit from repeat infusions.

COVID-19 and hepatic involvement: The liver as a main actor of the pandemic novel

In the natural history of SARS-CoV-2 infection, liver injury is frequent but quite mild and it is defined as any liver damage occurring during disease progression and treatment of infection in patients with or without pre-existing liver diseases. The underlying mechanisms for hepatic injury in patients with COVID-19 are still unclear but the liver damage in SARS-CoV-2 infection seems to be directly caused by virus-induced cytopathic effects. In this review, we will summarize all data of updated literature, regarding the relationship between SARS-CoV-2 infection, acute response and liver involvement. An overview will be given on liver injury, liver transplant and the possible consequences of COVID-19 in patients with pre-existing liver diseases.

A novel biomarker score for the screening and management of patients with plasma cell proliferative disorders

OBJECTIVE

Monoclonal plasma cell proliferative disorders comprise a wide spectrum of diseases associated to clonal B-cell expansion. Serum protein electrophoretic profile (SPEP) and circulating free light chains (FLCs) levels are the mainstay of diseases management. Recently, soluble (s) Syndecan-1 (SDC1, CD138) produced by myeloma plasma cells has been suggested in the monitoring and follow-up of patients with myeloma. The aim of our study is to evaluate sCD138 in addition with FLCs and SPEP for the screening of patients with different evolutive disease pathways.

PATIENTS AND METHODS

Sera from 73 patients with monoclonal gammopathy of undetermined significance (MGUS), 120 smoldering and 42 multiple myeloma (SMM and MM, respectively), 70 HCV-related mixed cryoglobulinemia (MC), 35 B-cell non-Hodgkin's lymphoma (B-NHL) and sera from 50 healthy donors (HD), were tested for sCD138, FLCs (assessed by means of ELISA and turbidimetric assay, respectively) and electrophoresis pattern (performed on Capillarys system) for the generation of a novel biomarker score (BS).

RESULTS

Our results were grouped according to the two main lines of disease progression (vs. MM or B-NHL): in one group we found BS mean values of 0.2, 3.4, 5.3, 7.1 for HD, MGUS, SMM and MM, respectively; in the other group of 0.2, 4.4, 6.7 for HD, MC and B-NHL.

CONCLUSIONS

We showed that BS mean values follow the ingravescence disease status towards the two main lines of progression to cancerous conditions; it could represent an additional useful tool in the management of screening and/or follow-up.

Free light chains a novel biomarker of cardiovascular disease. A pilot study

OBJECTIVE

Atherosclerosis and ischemic heart disease (IHD) are the major cause of morbidity and mortality but their inflammatory pathogenesis is still unclear. In this scenario, the role of serum free light chains (sFLC) has never been fully evaluated. The aim of the present study is to assess the clinical and pathogenetic role of sFLC in patients with IHD and to propose their use as a new biomarker for cardiovascular disease.

PATIENTS AND METHODS

We enrolled 117 patients, divided into 5 cohorts: 15 healthy controls, non-diabetic and without ischemic heart disease; 19 patients with type 2 diabetes (T2DM), without ischemic heart disease at recruitment; 39 patients with stable chronic angina; 27 patients with NSTEMI, 17 patients with acute STEMI. Serum sFLC and high-sensitive C-reactive protein (hs-CRP) were measured. Patients also underwent a transthoracic echocardiographic study.

RESULTS

sFLC were higher in patients with IHD and T2DM. However, we did not find statistically significant differences in sFLC concentration among subgroups. No correlation resulted between sFLC and hs-CRP levels. The median value of the sFLC κ/λ ratio in the population was 0.63, therefore stratifying it into two groups according to their levels. We found that an increase in left ventricular ejection fraction at 12 months was detected in 77% of patients with κ/λ ratio higher than 0.63 and 25% of patients with κ/λ ratio lower of 0.63 (p=0.016, OR=10.0 [1.8-55.6]).

CONCLUSIONS

Our study suggests that the sFLC, produced by the B-lymphocytes in the context of generalized immune activation, could play a pathogenetic role in acute coronary syndromes and that they could represent a novel risk biomarker of cardiovascular disease.

Biomarkers in HCV-related mixed cryoglobulinemia patients withnon-Hodgkin lymphoma

OBJECTIVE

Chronic Hepatitis C virus (HCV) infection can cause severe extrahepatic manifestations, such as mixed cryoglobulins (MC), up to the development of B cell nonHodgkin's lymphoma (B-NHL). Mechanisms transforming of HCV infection into lymphoproliferative and/or autoimmune disorders are still poorly understood. In course of HCV infection, the sustained virus-driven antigenic stimulation may probably induce a B-cell clonal expansion. Measurements of serum free light chains (FLCs) levels, considered as a direct marker of B cell activity, are analyzed with increasing interest in clinical practice, for diagnosis, monitoring and follow-up of plasma cell dyscrasia. Syndecan-1 (CD138) is a transmembrane heparan sulfate proteoglycan expressed and actively shed by most myeloma cells. Membrane CD138 represents the major receptor protein for HCV attachment to the hepatocyte surface and high levels of circulating sCD138 levels are detected in patients at early stage of B-cell chronic lymphocytic leukemia. This study is aimed to evaluate sCD138 and FLC levels as diagnostic biomarkers of HCV-related MC with B-NHL.

PATIENTS AND METHODS

We enrolled 35 HCV-MC-NHL patients, characterized for the specific type of cryoglobulins, and 25 healthy blood donors (HBD) as negative control. Serum sCD138 levels were determined using ELISA kits specific for human sCD138. Serum FLCs were assessed by means of the turbidimetric assay.

RESULTS

We found that serum levels of sCD138, as well as FLCs, were significantly higher in patients than in HBD (p<0.001).

CONCLUSIONS

In agreement with the definition of HCV-driven lymphoproliferative disorders as the consequence of a multifactorial and multistep pathogenetic process, we suggest that sCD138 and FLCs could be considered putative independent markers of worsening progression of the disease.

Immunological Role of IgG Subclasses

The loss of tolerance to self-antigens is the unequivocal "red line" of autoimmunity: both development of autoreactive T and B cells and production of polyclonal autoantibodies represent seminal keys to the pathogenesis of protean autoimmune diseases. Most of these autoantibodies are immunoglobulins G (IgG), functionally distinguished in four subclasses named IgG1, IgG2, IgG3, and IgG4, due to structural differences in the hinge and heavy chain constant regions. Different studies analyzed serum levels of IgG subclasses in the course of different disorders, showing that they might have a pathogenic role by regulating interactions among immunoglobulins, Fc-gamma receptors, and complement. To date, the mechanisms promoting different IgG subclasses distribution during the natural history of most autoimmune diseases remain somewhat unclear. Evidence from the medical literature shows that the serum IgG profile is peculiar for many autoimmune diseases, suggesting that different subclasses could be specific for the underlying driving autoantigens. A better knowledge of IgG subsets may probably help to elucidate their pathological task, but also to define their relevance for diagnostic purposes, patients' personalized management, and prognosis assessment.

Biomarkers of minimal residual disease in rituximab-treated patients with mixed cryoglobulinemia

Hepatitis C virus (HCV) represents the major risk factor for mixed cryoglobulinemia (MC), a small-vessel vasculitis that may evolve into an overt B-cell non-Hodgkin's lymphoma. Here, we aimed to identify a biomarker signature for the early diagnosis of minimal residual disease (MRD). We assessed free light chains (FLCs), IgM k,and IgM λ heavy/light chain (HLC) pairs, and vascular endothelial growth factor (VEGF) in sera from 34 patients with MC vasculitis (32 HCV- and 2 HBV-related), treated with low-dose rituximab (RTX). FLCs and IgM HLCs were measured by turbidimetric assay; VEGF by an enzyme-linked immunosorbent assay. After RTX, the positive (complete + partial) clinical and laboratory responses were of 85.29% and 50%, respectively; in contrast, the mean levels of FLCs, IgM HLCs, and VEGF were substantially unaffected in most patients and still above the normal range. In those achieving a reduction of FLCs and IgM k and λ chains values within the range of normality, we found that post-treatment free λ chains and IgM k values correlated with clinical and laboratory response. Our results suggest that high levels of FLCs, IgM HLCs, and VEGF could represent the signature of "dormant" B cell clones' activity that could be very useful to identify MRD indicative of possible relapse or worsening outcome.

IgG cryoglobulinemia

OBJECTIVE

Mixed Cryoglobulinemia is the most well-known Hepatitis C Virus (HCV)-associated extrahepatic manifestation. MC is both an autoimmune and B-lymphoproliferative disorder. Cryoglobulins (CGs) are classified into three groups according to immunoglobulin (Ig) composition: type I is composed of one isotype or Ig class. Type II and type III mixed CGs are immune complexes composed of polyclonal IgGs acting as autoantigens and mono, polyclonal or oligoclonal IgM with rheumatoid factor activity. IgG1 and IgG3 are the predominant subclasses involved. This study shows the simultaneous presence of IgG-RF and IgG3, supporting the hypothesis of an involvement of this subclass in the initiation of early stages of CGs.

PATIENTS AND METHODS

We describe a case series of six HCV-positive patients, all of whom had peripheral neuropathy and transient ischemic attacks, presenting cryoprecipitates formed by IgG3 and IgG1. Cryoprecipitate IgG subclass research was carried out by immunofixation electrophoresis by using antisera against IgG1, IgG2, IgG3, and IgG4.

RESULTS

Our six patients presented with an immunochemical pattern characterized by the mere presence of IgG1 and IgG3 subclasses with probable RF activity and one of these six patients exhibited monoclonal IgG3 in his cerebrospinal fluid.

CONCLUSIONS

We can hypothesize that the IgG passage through the blood-brain barrier could have contributed to the cause of TIAs, through a mechanism involving the precipitation of circulating immune complexes formed by the two subclasses in the intrathecal vessels.

Serum immunoglobulin free light chain levels in systemic autoimmune rheumatic diseases

Several reports have highlighted the abnormal increments of serum immunoglobulin free light chains (FLCs) in the course of systemic autoimmune rheumatic diseases (SARD), but a comparative analysis among different conditions is still lacking. A strong association between elevated FLC and hepatitis C virus (HCV)-related mixed cryoglobulinaemia (HCVMC) has been well established. Here, we aimed to analyse serum FLC levels in patients with four different SARD in comparison with HCVMC. Using a turbidimetric assay, free κ and λ chains were quantified in sera from 198 SARD patients (37 rheumatoid arthritis, RA; 47 systemic lupus erythematosus, SLE; 52 anti-phospholipid syndrome, APS; 62 primary Sjogren's syndrome, pSS), 62 HCVMC and 50 healthy blood donors (HD). All patient groups showed increased κ levels when compared to HD: 33·5 ± 2·6 mg/l in HCVMC, 26·7 ± 2·3 mg/l in RA, 29·7 ± 1·9 mg/l in SLE, 23·8 ± 1·1 mg/l in APS, 24·2 ± 1·1 mg/l in pSS; 10·1 ± 0·6 mg/l in HD. Free λ levels displayed a significant increase only for HCVMC (20·4 ± 1·4 mg/l) and SLE (18·4 ± 1·0 mg/l) compared to HD (13·6 ± 0·9 mg/l). The increase of κ compared to λ takes into account a κ /λ ratio of 1·6 for all groups. Our results substantially analyse and strengthen the association between FLC and SARD focusing the questions regarding their role in the pathogenesis and diagnosis of human diseases. Unfortunately, the biochemical differences distinguishing normal from pathological FLC have not been identified. Production of different isotypes is probably connected to still-unknown pathways.

Plasmatic free light chains in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), as systemic disease, is accompanied by different indexes of inflammation. Free light chains of immunoglobulins (FLCs), produced by plasmacells, are released in slight excess for the immune requests, with still poorly defined physiological role but surely they represent a marker of inflammation. In order to evaluate their levels and correlate them with hyperandrogenism, we have studied a group of PCOS patients, age range 18-37 yrs, mean ± SEM body mass index (BMI) 24.1 ± 0.9 kg/m²), compared with age- and BMI-matched controls, with assay of k and λ FLCs, by turbidimetric method, and their ratio in blood plasma. PCOs exhibited higher levels vs. controls: (mean ± SEM λ: 10.0 ± 0.85 mg/L vs. 8.41 ± 0.45 mg/L; k: 12.45 ± 0.72 mg/L vs. 6.41 ± 0.34 mg/L; k/λ: 1.31 ± 0.07 vs. 0.78 ± 0.04). A significant direct correlation was observed between λ-FLCs and testosterone levels, no correlation was indeed found with HOMA-IR index. These data confirm high levels of FLCs in PCOS, suggesting systemic inflammatory state and a possible role in the pathophysiology of such complex syndrome.

Circulating tumor cell-related transcripts in blood as prognostic biomarkers of early recurrence after liver resection for colorectal metastases

BACKGROUND

Several prognostic factors were proposed to improve early detection of recurrence after liver resection of metastases of colorectal cancer. Circulating tumor cell-related transcripts were evaluated in colorectal cancer patients with conflicting results. The aim of this study was to investigate usefulness of carcinoembryonic antigen CAM5, epidermal growth factor receptor, and ERCC1 transcripts in the bloodstream as predictive factors of recurrence in patients who underwent liver resection for metastases of colorectal cancer.

METHODS

Peripheral blood was collected from 29 patients at the time of the colorectal cancer liver metastasis resection, and from 25 normal controls. Follow-up draws (FUDs) were also performed at 30 days, and 3 and 12 months since surgery. On each sample, carcinoembryonic antigen CAM5, ERCC1, and GAPDH mRNAs were examined by quantitative reverse transcription (qRT).

RESULTS

Carcinoembryonic antigen transcript levels were linearly correlated to the number of spiked cells (qRT analytical limit = five cells). Among 29 patients (20 M/9 F; mean age 63 years (range 32-79), highly significant levels of carcinoembryonic antigen, if compared to the baseline, were detected in those relapsing after surgery (P <0.05). The main differences were between the 1st- and 12th-month FUDs. Significantly higher levels of carcinoembryonic antigen were also detected in patients who died from disease progression during the follow-up (as evaluated at 30 days and 90 days FUDs).

CONCLUSIONS

Blood carcinoembryonic antigen-mRNA absolute copy number overtime variation can represent a valid early predictor of relapse after liver resection in colorectal liver metastases patients. Prospective studies, in the context of large clinical trials, will provide further data to also qualify ERCC1 as a predictive biomarker for decisions on therapeutic strategies.

Serological profile of asymptomatic HCV positive patients with low level of cryoglobulins

Clinical spectrum of hepatitis C virus (HCV)-related cryoglobulinemia varies from an asymptomatic presentation to severe vasculitis and lymphoma. A recent study in HCV-negative patients suggests that low cryoglobulins (CGs) levels are responsible for severe renal and neurological complications. The aim of this study was to identify a panel of serological biomarkers associated with low levels of CGs in HCV-positive patients. We studied a population of 79 untreated patients with chronic HCV infection: 13 naïve patients without CGs; 28 patients with asymptomatic mixed cryoglobulinemia (MC) and low levels of CGs (16/28 with polyclonal type III and 12/28 with microheterogeneous type III CGs); 38 patients with symptomatic MC and high levels of type II CGs. Serum samples were collected and examined for rheumatoid factor (RF) IgG and IgM, free light chains (FLCs) and C3 and C4 complement components. We found that RF-IgG and IgM, free k chains and k+λ were increased while C4 component was reduced, both in symptomatic and asymptomatic patients. Our results suggest that, even in absence of MC symptoms, the low levels of CGs may represent a trigger of activation for immune system in course of HCV infection. The identification of a correlated biomarkers panel could improve the clinical management of these patients and pave the way for target treatment strategies. © 2018 BioFactors, 45(3):318-325, 2019.

Serum biomarkers for sepsis in children with febrile neutropenia and cancer

The National Institute for Health and Care Excellence (NICE) defines febrile neutropenia or "neutropenic sepsis" as a patient with an absolute neutrophil count (ANC) less than 0.5 x 109/L and temperature >38°C or signs and symptoms of sepsis.

MON-448 Inflammatory and Oxidative Stress Parameters as Criteria of Classification of Metabolic Phenotypes of Insulin Resistance

In previous studies, we have shown that metabolic syndrome (MetS) and adult growth hormone deficiency (GHD) share different biochemical features, such as insulin-resistance (IR) but differ in antioxidant pattern. On the other hand, immunoglobulin free light chains (FLCs) are molecules with biological functions which are still incompletely known. In order to compare different populations with IR and, consequently, classify different phenotype of IR, we have evaluated FLCs and Total Antioxidant Capacity (TAC) in 3 groups of patients with IR due to different diseases: group A, patients with GHD (n=31, 24-69 ys, mean±SEM BMI 26.8±1.5 kg/m²⁾; group B, patients with MetS (n=29, 29-70 ys, mean±SEM BMI 31.9±1.3 kg/m²); group C hyperferritinaemia (HF) (n=33, 28-78 ys, mean±SEM BMI 31.1±0.99 kg/m²). All patients underwent an oral glucose tolerance test; HOMA-IR was calculated; moreover, a morning blood sample was collected for evaluation of FLCs (assessed by turbidimetric assay) and TAC (assessed by spectrophotometric method, using the system H₂O₂-metmyoglobin, and expressed as Lag, latency time before the appearance of the radical form of the chromogen ABTS). HOMA-IR, as expected, was high in all three groups (group A 3.13±0.43, group B 3.16±0.28, group C 4.62 ±0.51), significantly higher in group C vs the other two groups. The parameters of inflammation and oxidative stress were significantly different in group A vs the other two groups (FLCs k 36.2±7.0 mg/l vs 15.4±0.9 in group B and 17.8±8.0 in group C; FLCs lambda 19.4±2.6 vs 11.3±0.7 in group B and 12.7±7.3 in group C; Lag 65.0±5.3 sec vs 82.9±6.2 in group B and 83.9±5.4 in group C). These data confirm that different mechanisms of oxidative stress and inflammation underlie these three subtypes of IR, and could be used to classify different phenotypes of these complex syndrome.

Free light chains and autoimmunity

The study of free light chains (FLCs) has grown as area of enormous interest for many clinicians with the aim of disclosing the exact biological role and potential use of FLCs in the clinical routine. Moreover, the attention given to immunological functions of FLCs has sparked a new light into their pathogenic contribution in different chronic autoimmune-based inflammatory diseases. The release of intracellular antigens following cell death or ineffective clearance of apoptotic debris, modification of self-antigens, and molecular mimicry may trigger the production of immunoglobulins after activation and polyclonal expansion of B cells, by which FLCs are released. The discovery of polyclonal FLCs as potential biomarkers started with the observation of their increased concentrations in a variety of biological fluids related to patients with autoimmune diseases. This review deals with the use of polyclonal FLCs for identifying severity and monitoring outcome after treatment in some autoimmune diseases, namely systemic lupus erythematosus, myasthenia gravis, systemic sclerosis, rheumatoid arthritis and Sjögren's syndrome, as supported by the fact that levels of FLCs correlate with both B cell activation markers and other specific markers of disease activity. In a near future, following the evidence shown, FLCs might probably work as early prognostic markers of severity and also as indicators of response to treatment or early assessment of relapse in selected autoimmune diseases.

Plasmatic free light chains as inflammatory marker in insulin resistance: comparison of metabolic syndrome with adult growth hormone deficiency

Biological functions of immunoglobulin-free light chains (FLCs), other than in chronic inflammatory diseases, are still poorly defined; the field of insulin resistance (IR) has not been investigated, despite the strict relationships with oxidative stress (OS) and inflammation. Therefore, we evaluated FLCs levels and their relationships with metabolic parameters in adult growth hormone deficiency (GHD) and metabolic syndrome (MetS), both characterized by IR. One hundred subjects were enrolled: group A, patients with GHD [n =31, 24-69 years, mean ± SEM body mass index (BMI) 26.8 ± 1.5 kg/m² ]; group B, patients with MetS (n = 29, 21-70 years, BMI 31.9 ± 1.3); group C, controls (N = 40, 21-62 years, BMI 21.6 ± 1.1). Groups were matched by age range and, for patients, by BMI. Morning blood sample was collected for metabolic parameters and FLCs, assessed by turbidimetric assay. GHD patients show levels of FLCs significantly higher than MetS and controls (mean ± SEM κ 37.21 ± 6.97, 15.27 ± 0.86, 12.34 ± 0.85 mg/l; λ 19.44 ± 2.61, 11.78 ± 0.72 and 11.67 ± 0.77 mg/l; κ/λ ratio 1.77 ± 0.13, 1.38 ± 0.09; and 1.10 ± 0.06, respectively); only κ were higher in MetS versus controls. Therefore, the ratio showed progressive declining values in GHD versus MetS versus controls. Our data show increased FLCs levels in GHD and MetS, with the highest values in the former. Both conditions show OS, but with different molecular patterns. FLCs may contribute to chronic inflammation, leading to OS, and cardiovascular complications of GHD. Prognostic and therapeutic implications require further investigation. © 2018 BioFactors, 44(5):480-484, 2018.

Different biochemical patterns in type II and type III mixed cryoglobulinemia in HCV positive patients

BACKGROUND

Reversible cryoprecipitability of proteins is observed as a concomitant feature of immune complex formation. Mixed cryoglobulinemia (MC) is systemic vasculitis, associated with mixed IgM and IgG cryoglobulins (CGs) showing rheumatoid factor (RF) activity. It is frequently associated with hepatitis C virus (HCV). This study investigates the presence of IgG RF and anti-nuclear antibodies (ANA) in cryoprecipitates of patients with type III and type II MC, to understand the biochemical patterns associated with different types of MC to a greater degree.

METHODS

Sera from 70 HCV untreated patients with type III or type II MC were tested by immunofixation for IgG3 and through ELISA for IgG RF. Cryoprecipitates were analysed for ANA by indirect immunofluorescence to identify specific patterns.

RESULTS

After stratification according to MC type, the ANA patterns between type II and type III MC were statistically different. IgG3 levels and IgG-RF positivity were significantly higher in type III cryoprecipitate. We observed a higher positivity of IgG3 and a significant difference between the liver fibrosis stage, ANA and IgG-RF in the cryoprecipitate.

CONCLUSION

Results show a combination of biochemical markers and autoantibodies associated to mixed cryoglobulinemia; these findings could be further investigated in order to ascertain their usefulness in assessing the risk for the development of mixed cryoglobulinemia.

Free light chains of immunoglobulins in patients with systemic sclerosis: correlations with lung involvement and inflammatory milieu

AIM

Humoral immunity and B cells are thought to play an important role in the pathophysiology of the systemic sclerosis (SSc). The production of free light chains (FLC) of immunoglobulins is abnormally high in several pathological autoimmune conditions and reflects B cell activation. Furthermore, FLCs demonstrated different biological activities including their capability to modulate the immune system, proteolytic activity and complement cascade activation. The aims of this study are to determine the FLC levels in patients with SSc compared with healthy controls (HC) and to study their possible association with organ involvement and disease characteristics.

METHODS

Sixty-five patients with SSc and 20 HC were studied. Clinical and immunological inflammatory characteristics were assessed for all the patients with SSc. κ-FLC and λ-FLC, interleukin 6 (IL-6) and B cell activating factor levels were measured.

RESULTS

The mean serum κ-FLC levels and FLC ratio were significantly higher in patients with SSc compared with HC, while the serum λ-FLC levels were comparable.The levels of FLC were comparable in patients with diffuse skin disease and limited skin involvement, while κ-FLC levels were increased in patients with restrictive lung (forced vital capacity (FVC) <80%) disease (26.4±7.4 mg/L) when compared with patients with FVC ≥80% (19.6±7.3 mg/L, P=0.009). In patients with SSc, the levels of serum κ-FLC level directly correlated with the IL-6 levels (R=0.3, P=0.001) and disease activity (R=0.4, P=0.003).

CONCLUSIONS

FLC levels are elevated in SSc and high levels are associated with lung involvement and with a higher degree of inflammation, supporting a possible role of B cell activation in the pathophysiology of the disease.

IgG3 subclass: A possible trigger of mixed cryoglobulin cascade in hepatitis C virus chronic infection

HCV is a hepatotropic and lymphotropic virus and is the most frequent cause of "benign" mono-oligoclonal B-lymphocyte proliferation, observed in mixed cryoglobulinemia (MC). The study aims to investigate the presence, prevalence and characteristics of the subclasses of cryoglobulins in HCV-patients to look for a relationship with MC. Fifty HCV-infected patients with cryoglobulins were enrolled. IgG subclasses were characterized in cryoprecipitate, and serum IgG and IgM Rheumatoid Factor (RF) were determined. Patients were stratified into two subgroups according to the presence of IgG3 subclass. Differences were observed in supernatant IgM, IgG3-positive and IgG3-negative patients with a higher IgM concentration in the IgG3-negative cohort (p=0.03). Higher IgM-RF was detected in the IgG3-negative group (p=0.01). IgG3-positive group showed higher IgG-RF compared to the IgG3-negative group (p<0.0001). IgG3-negative/monoclonal-IgM patients had higher cryocrit compared to IgG3-negative/polyclonal-IgM patients (p<0.01). C4 levels were higher in the polyclonal-IgM group compared to monoclonal-IgM group (p<0.01). We speculate that cryoglobulins are part of a progressive clonal selection process in which, B-cells are stimulated to produce oligoclonal IgG3 with RF activity. The persistence of the antigenic stimulus elicits the production of polyclonal IgM-RF and subsequently the formation of oligoclonal IgG/polyclonal IgM containing cryoglobulins. In the last stage, a monoclonal IgM-RF clone is formed which may coexist with a monoclonal IgG3-RF clone.

PAX3d mRNA over 2.76 copies/µL in the bloodstream predicts cutaneous malignant melanoma relapse

OBJECTIVE

The aim of this study was to evaluate if our molecular algorithm, based on tumor circulating transcripts, may predict relapse risk in cutaneous malignant melanoma (CMM).

RESULTS

The multi-marker panel was able to differentiate patients with CMM from HC with high diagnostic sensitivity and specificity, especially for MITF-m and TGFB2 (91-100%) whose levels decreased during follow-up of recurrence-free patients, and remained stable in the case of relapse. PAX3d higher than 2.76 copies/µL emerged as a promising biomarker [specificity = 75-93% and negative predictive value = 75-98%] to stratify subjects at high risk of CMM recurrence independently of age, gender and AJCC staging [OD = 9.5(3.2-28.0), p < 0.001]. The survival analysis confirmed PAX3d performance in relapse prediction with significant differences in recurrence risk 12 months after the basal time-point (p = 0.008).

MATERIALS AND METHODS

Peripheral blood was collected from 111 CMM patients and from 87 healthy controls (HC) randomly selected. Each specimen was examined by qRT-PCR analysis for the expression of 3 tumor-related transcripts (PAX3d, MITF-m and TGFB2) at diagnosis, and at the following 6 and 12 months during clinical monitoring.

CONCLUSIONS

We demonstrated the usefulness of our molecular algorithm to indirectly detect circulating melanoma cells in blood, along with PAX3d capability to assess patients' progression and relapse prediction.

Free light chains: Eclectic multipurpose biomarker

The production of antibodies is accompanied by a slight excess of synthesis of κ and λ immunoglobulin light chains; small amounts of them are released in the peripheral blood and can also be found in various body fluids, such as synovial fluid, cerebrospinal fluid, urine and saliva. They are rapidly filtered by the glomerulus and >99% are reabsorbed from the cells of the proximal convoluted tubule, making them present in the urine in only trace amounts. The production of an excess of protein without a reason or a specific function in a biological system is rare. Free light chains, considered for years a waste product of Ig synthesis, are currently known to be very active molecules, able to bind antigens as well as whole immunoglobulin and helping to develop specific antibody affinity. The ability of free light chains to activate mast cells and then become an active part of the pathogenic mechanisms of chronic inflammatory diseases has increased interest in their clinical use, both as an attractive therapeutic target or as a biochemical marker of disease evolution or remission. This is an overview of relevant scientific interest that immunoglobulin light chains κ and λ have attracted over the years, a report on the progress in knowledge about their structure and function, with a special focus on their biological meaning and potential clinical utility in different diseases.

Serum free light chain quantitative assays: Dilemma of a biomarker

BACKGROUND

Serum free light chains detection assays are consistently meeting greater interest for the diagnosis and monitoring of monoclonal gammopathies and plasma cell dyscrasias. Nowadays, there are neither standardized methods nor reference material for the determination of free light chains; for this reason, it is important to compare two different assays used in clinical laboratory.

METHODS

We evaluated 300 serum samples from patients with B-cell disorders and compared the analytical performances of both assay. Each test was assayed on both testing platforms (Siemens Dade Behring BN II Nephelometer and SPAPLUS by The Binding Site). κ/λ ratios were determined and compared. Results were analyzed by Passing-Bablok and Bland-Altman plots to evaluate comparability of the two techniques and to determine bias.

RESULTS

The reproducibility of both assays is acceptable, reaching minimum and desirable analytical goals derived from biological variability. However, values are not interchangeable between systems. This study shows that the two systems do not allow results to be transferred from one method to the other even if they display good agreement.

CONCLUSION

Our study highlights the importance of elaborating an international standard for free light chains quantification in order to offer homogeneous results as well as guarantee harmonization of values among laboratories. Moreover, the assays should be validated in specific patient groups to determine that they are clinically fit for purpose.

Comparison of Fully Automated and Semiautomated Systems for Protein Immunofixation Electrophoresis

BACKGROUND

In order to establish a diagnosis of monoclonal gammopathy, it is necessary to detect and identify monoclonal components. To confirm the immunological nature of the proteins, the next step is to define their composition in heavy and light chains using immunofixation. The purpose of this study was to compare two different instruments, one semiautomated and the other fully automated for serum and urine immunofixation.

METHODS

We selected 150 sera and 100 urines from patients admitted for routine analysis, which were analyzed by immunofixation to characterize monoclonal components.

RESULTS AND CONCLUSION

Comparison study showed a difference in the identification of small monoclonal components and hypogammaglobulinemia, in serum and urine, between the two analyzers. We also observed a difference in the length of the electrophoretic pattern that is of considerable importance as it leads to a better resolution of the gamma region, allowing to identify even the smallest monoclonal component that can be easily hide in an oligoclonal pattern. For this reason, there is need to ameliorate commercial immunofixation assays. It is essential to improve data harmonization and standardize measurement procedures in order to guarantee a correct diagnosis for the right patient care.

The Hemo One Autoanalyzer for Glycated Hemoglobin Assay

BACKGROUND

Glycated hemoglobin (HbA1c) is widely used as a clinical marker of long-term blood glucose concentration in patients with diabetes. The clinical laboratory plays a vital role in the diagnosis and management of diabetes. Many methods for the measurement of HbA1c have been developed based on different analytical principles, often causing discordant results. For this reason, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) established a reference method for HbA1c assay, namely, high-performance liquid chromatography-mass spectrometry/capillary electrophoresis (HPLC-MS/CE).

OBJECTIVE

In order to evaluate in parallel 2 different routine methods, namely, ion-exchange HPLC and immunoturbidimetry.

METHODS

For our comparison study, we used the Tosoh G8 HPLC analyzer and the Hemo One autoanalyzer system to test 100 blood specimens for HbA1c concentration, the values of which ranged from 4.3% (23.5 mmol/mol) to 14.7% (137 mmol/mol).

RESULTS

Concordance between HPLC and the immunoturbidimetric method revealed perfect agreement with a Kappa value of 0.828.

CONCLUSIONS

Our results confirm the validity of the immunoturbidimetric method compared with the reference method. Our findings highlight that these 2 methods are equivalent for the diagnosis and therapeutic monitoring of diabetes.

Urinary Albumin Detection: Comparison of Two Different Methods

BACKGROUND

Monitoring urinary albumin is a useful method in clinical practice for the management of diabetic nephropathy, chronic kidney disease, and hypertension. Currently there are neither standardized methods nor reference material for the determination of urinary albumin; for this reason it is useful to compare different assays used in clinical laboratory.

OBJECTIVES

The aim of this study is to verify analytical performance of an immunoturbidimetric assay on Roche Cobas 8000 platform and to compare urinary albumin results with those obtained by immunonephelometry on Siemens Dade Behring BN II Nephelometer.

RESULTS

The method comparison showed a good linear relationship, confirmed by Passing-Bablok and Bland-Altman plots. The turbidimetric assay meets the requirements of accuracy and precision for the practice of medical diagnostics and clinical use.

CONCLUSIONS

The present study can contribute to the methods standardization and harmonization of urinary albumin assay.

Description of an Automated Method for Urea Nitrogen Determination in Bronchoalveolar Lavage Fluid (BALF) of Neonates and Infants

Bronchoalveolar lavage (BAL) partially recovers both the instilled saline and the alveolar fluid, so-called epithelial lining fluid (ELF), but a correction for the dilution due to the BAL technique itself is needed to know the amount of recovered ELF. In this regard, urea nitrogen may be useful and has been proposed to calculate ELF. The aim of the present study was to develop and validate a new method to measure urea nitrogen in BAL fluid (BALF). We used 19 BALF samples obtained from neonates and infants with different respiratory conditions. The urea nitrogen assay was carried out on Cobas c311 analyzer (Roche Diagnostics). A validation study shows that the method is perfectly linear (R(2) = 0.999), sensitive (limit of detection = 0.055 mg/dL; limit of quantification = 0.16 mg/dL), repeatable (low = 0.15 ± 0.02, 13.3%; high = 1.80 ± 0.02, 1.1%), reproducible (low = 0.14 ± 0.02, 14.2 %; high = 1.76 ± 0.04, 2.2 %) with accuracy ranging between 93-96%. Our results support the robustness of validated procedure since the described method appears simple, precise, rapid, and suitable for routine analysis. Thus, it may be used to correct concentration of various noncellular BAL components and calculate their ELF amounts in neonates and infants.