Alterations in plasma proteome during acute COVID-19 and recovery.

BACKGROUND: The severe course of COVID-19 causes cardiovascular injuries, although the mechanisms involved are still not fully recognized, linked, and understood. Their characterization is of great importance with the establishment of the conception of post-acute sequelae of COVID-19, referred to as long COVID, where blood clotting and endothelial abnormalities are believed to be the key pathomechanisms driving circulatory system impairment. METHODS: The presented study investigates temporal changes in plasma proteins in COVID-19 patients during hospitalization due to SARS-CoV-2 infection and six months after recovery by targeted SureQuant acquisition using PQ500 panel. RESULTS: In total, we identified 167 proteins that were differentially regulated between follow-up and hospitalization, which functionally aggregated into immune system activation, complement and coagulation cascades, interleukins signalling, platelet activation, and extracellular matrix organization. Furthermore, we found that temporal quantitative changes in acute phase proteins correlate with selected clinical characteristics of COVID-19 patients. CONCLUSIONS: In-depth targeted proteome investigation evidenced substantial changes in plasma protein composition of patients during and recovering from COVID-19, evidencing a wide range of functional pathways induced by SARS-CoV-2 infection. In addition, we show that a subset of acute phase proteins, clotting cascade regulators and lipoproteins could have clinical value as potential predictors of long-term cardiovascular events in COVID-19 convalescents.

Characterization of Inflammation/Immune-, Acute Phase-, Extracellular Matrix-, Adhesion-, and Serine Protease-Related Proteins in the Amniotic Fluid of Women With Early Preterm Prelabor Rupture of Membranes.

PROBLEM: To determine whether altered concentrations of various inflammation/immune-, acute phase-, extracellular matrix-, adhesion-, and serine protease-related proteins in the amniotic fluid (AF) are independently associated with microbial invasion of the amniotic cavity and/or intra-amniotic inflammation (MIAC/IAI), imminent spontaneous preterm delivery (SPTD; ≤7 days), and major neonatal morbidity/mortality (NMM) in women with early preterm prelabor rupture of membranes (PPROM). METHOD OF STUDY: This was a retrospective cohort study involving 111 singleton pregnant women with PPROM (24-31 weeks) undergoing amniocentesis to diagnose MIAC/IAI. The following proteins were measured in stored AF samples by enzyme-linked immunosorbent assay (ELISA): APRIL, DKK-3, Gal-3BP, IGFBP-2, IL-8, VDBP, lumican, MMP-2, MMP-8, SPARC, TGFBI, TGF-ß1, E-selectin, ICAM-5, P-selectin, haptoglobin, hepcidin, SAA1, kallistatin, and uPA. RESULTS: Multivariate logistic regression analyses revealed that (i) elevated APRIL, IL-8, MMP-8, and TGFBI levels in the AF, reduced lumican and SPARC levels in the AF, and high percentages of samples above the lower limit of quantification for AF TGF-ß1 and uPA were significantly associated with MIAC/IAI; (ii) elevated AF levels of IL-8 and MMP-8 were significantly associated with SPTD within 7 days; and (iii) elevated AF IL-6 levels were significantly associated with increased risk for major NMM, when adjusted for baseline covariates. CONCLUSION: ECM (lumican, SPRAC, TGFBI, and TGF-ß1)- and serine protease (uPA)-associated proteins in the AF are involved in the regulation of the host response to infection/inflammation in the amniotic cavity, whereas AF inflammation (IL-8, MMP-8, and IL-6)-associated mediators are implicated in the development of preterm parturition and major NMM in early PPROM.

Observational study of effects of HIV acquisition and antiretroviral treatment on biomarkers of systemic immune activation.

To assess whether biomarkers of systemic inflammation are associated with HIV acquisition or with the timing of ART initiation ("immediate", at diagnosis, versus "deferred", at 24 weeks post-diagnosis) in men-who-have-sex-with-men (MSM) and transgender women, we conducted a retrospective study comparing inflammatory biomarkers in participants' specimens collected before infection and after ≥2 years of effective ART. We measured biomarkers in four longitudinally collected plasma, including two specimens collected from each participant before and two after HIV acquisition and confirmed ART-suppression. Biomarkers were quantified by enzyme-linked immuno-assay or Meso Scale Discovery. When evaluating systematic variation in these markers over time, we found that multiple biomarkers consistently varied across participants' two pre-infection or two post-ART-suppression specimens. Additionally, we compared changes in biomarkers after vs before HIV acquisition. Across 47 participants, the levels of C-reactive protein (CRP), monocyte chemo-attractant protein-1, tumor necrosis factor-α and interferon gamma-induced protein-10 significantly increased while leptin and lipopolysaccharide binding protein (LBP) significantly decreased following HIV infection. Randomization to deferred-ART initiation was associated with greater increases in CRP and no decrease in LBP. Acquisition of HIV appeared to induce systemic inflammation, with elevation of biomarkers previously associated with infections and cardiovascular disease. Initiation of ART during the early weeks of infection tempered the increase in pro-inflammatory biomarkers compared to delaying ART for ~24 weeks after HIV diagnosis. These findings provide insight into potential mediators by which immediate-ART initiation improves health outcomes, perhaps because immediate-ART limits the size of the HIV reservoir or limits immune dysregulation that in turn trigger systemic inflammation.

Multiplex Assay to Determine Acute Phase Proteins in Modified Live PRRSV Vaccinated Pigs.

Acute phase protein (APP) response to vaccine challenges is an attractive alternative to natural infection for identifying pigs with increased disease resilience and monitoring the productive performance. Currently, the methods used for APP quantification are diverse and often based on techniques that use antibodies that are not necessarily pig specific. The objective of this work is the development of a method based on a UPLC-SRM/MS system for simultaneous determination of haptoglobin, apolipoprotein A1, C-reactive protein, pig-major acute protein, and serum amyloid A and its application in pigs to monitor the effect of a vaccine administered against porcine reproductive and respiratory syndrome virus (PRRSV). With the aim of tracing the complete analytical process for each proteotypic peptide, a synthetic QconCat polypeptide construct was designed. It was possible to develop an SRM method including haptoglobin, apolipoprotein A1, pig-MAP, and serum amyloid A1. The PRRSV vaccine only affected haptoglobin. The pigs with positive viremia tended to show higher values than negative pigs, reaching significant differences in the three haptoglobin SRM-detected peptides but not with the data acquired by immunoenzymatic and spectrophotometric assays. These results open the door to the use of SRM to accurately monitor APP changes in experimental pigs.

Plasma concentration of serum amyloid A and lipopolysaccharide binding protein in horses with laminitis resulted from hindgut acidosis.

Many studies have shown a strong correlation between Hindgut Acidosis (HGA) and the occurrence of laminitis in horses; therefore, the early diagnosis of HGA is essential. In this study, we investigated changes in the plasma concentrations of lipopolysaccharide-binding protein (LBP) and serum amyloid A (SAA) as inflammatory markers in horses with laminitis. Sixteen healthy male Arabian horses that had cecal cannulation without visible laminitis or general symptoms were randomly divided into two groups. The horses were fed two different diets in a forage-to-concentrate ratio. Blood samples were collected on Days 1, 10, and 20. The primary objective of this study was to analyze plasma levels of LBP and SAA. Cecal specimens were obtained from each equine subject on three designated days: days 1, 10, and 20. The second objective was to assess the levels of pH and volatile fatty acids (VFA) in the samples. Throughout the study period, horses fed a high-concentrate diet exhibited a significantly elevated average lameness grade on days 10 and 20 compared to the initial stage (P < 0.001). On day 20, a significant increase in the concentration of SAA was observed in horses fed a high-concentrate diet, in contrast to the initial stage of the study. LBP levels in the plasma were significantly elevated on days 10 and 20 in horses fed a high-concentrate diet. Based on our findings, it is recommended that the evaluation of plasma LBP concentrations is more effective than SAA for the early identification of HGA in horses fed a high-grain diet.

Serum bile acids profiles are altered without change of the gut microbiota composition following a seven-day prednisolone therapy in severe alcoholic hepatitis.

Severe Alcoholic Hepatitis (sAH) is an acute form of liver injury caused by chronic and heavy alcohol drinking. A one-month corticosteroids course is the only sAH reference treatment, and its interactions with the Gut Microbiota (GM), which is a key contributor to liver injury, remain unknown. To evaluate the evolution of the GM in sAH patients, we retrospectively investigated the composition of the GM of 27 sAH patients at the Amiens University Hospital before (D0) and after (D7) a 7-day corticotherapy course using fecal metagenomics sequencing. We also quantified fecal Short-Chain Fatty Acids (SCFA) and fecal and serum Bile Acids (BA), as well as serum Lipopolysaccharide-Binding Protein (LBP). Overall, the community and taxonomical analyses did not reveal any GM evolution between D0 and D7, nor did the SCFA profiles analysis. However, in serum but not fecal samples, the ratio of glyco-conjugated to tauro-conjugated BA was significantly reduced at D7, independently of the response to treatment, while two BA were enriched in non-responder patients. LBP concentration significantly diminished between D0 and D7, which may indicate an improvement of the gut barrier. The stability of the GM of sAH is interesting in the perspective of new treatments based on GM modulation.

There is a gap in the understanding of the effects of corticosteroids on the gut microbiota of severe alcoholic hepatitis patients.In this study, the composition of the Gut Microbiota of sAH patients treated with prednisolone remains unchanged after 7 days of prednisolone treatment.Short-Chain Fatty Acid profiles are not impacted by the treatment, while Bile Acids profiles change in serum but not in stool samples.Responders and non-responders show different lipopolysaccharide-binding protein serum concentration evolution across time, as well as distinct Bile Acid profiles.

Pig Acute Phase Proteins as Non-Antibody Systemic Biomarkers of Intracellular Infections.

As an alternative to traditional serological markers, that is, antibodies, for serum-based specific diagnosis of infections, circulating non-antibody markers may be used to monitor active disease. Acute phase proteins (APPs) are a prominent class of such markers widely used for diagnosing ongoing inflammation and infection. In this chapter, basic theoretical and practical considerations on developing APP assays and using APPs as markers of ongoing infection are presented with a specific focus on intracellular infections in pigs. Examples on APP-based monitoring of infection in pigs with viruses such as porcine respiratory and reproductive syndrome virus (PRRSV), porcine endemic diarrhea virus (PEDV), and influenza A virus (IAV), as well as intracellular bacteria (Lawsonia intracellularis) and the protozoan intracellular parasites Toxoplasma gondii and Cryptosporidium parvum are presented, with an emphasis on major pig APPs C-reactive protein (CRP), haptoglobin, serum amyloid A (SAA), and pig major acute phase protein (pig-MAP). The performance of these APPs as biomarkers in a range of experimental infection studies in pigs is described as examples on their use for estimating the severity of infection, vaccine efficacy, herd health characterization, and differential diagnosis.

Identification of novel biomarkers of acute phase response in chickens challenged with Escherichia coli lipopolysaccharide endotoxin.

BACKGROUND: The chicken's inflammatory response is an essential part of the bird's response to infection. A single dose of Escherichia coli (E. coli) lipopolysaccharide (LPS) endotoxin can activate the acute phase response (APR) and lead to the production of acute phase proteins (APPs). In this study, the responses of established chicken APPs, Serum amyloid A (SAA) and Alpha-1-acid-glycoprotein (AGP), were compared to two novel APPs, Hemopexin (Hpx) and Extracellular fatty acid binding protein (Ex-FABP), in 15-day old broilers over a time course of 48 h post E.coli LPS challenge. We aimed to investigate and validate their role as biomarkers of an APR. Novel plant extracts, Citrus (CTS) and cucumber (CMB), were used as dietary supplements to investigate their ability to reduce the inflammatory response initiated by the endotoxin. RESULTS: A significant increase of established (SAA, AGP) and novel (Ex-FABP, Hpx) APPs was detected post E.coli LPS challenge. Extracellular fatty acid binding protein (Ex-FABP) showed a similar early response to SAA post LPS challenge by increasing ~ 20-fold at 12 h post challenge (P < 0.001). Hemopexin (Hpx) showed a later response by increasing ∼5-fold at 24 h post challenge (P < 0.001) with a similar trend to AGP. No differences in APP responses were identified between diets (CTS and CMB) using any of the established or novel biomarkers. CONCLUSIONS: Hpx and Ex-FABP were confirmed as potential biomarkers of APR in broilers when using an E. coli LPS model along with SAA and AGP. However, no clear advantage for using either of dietary supplements to modulate the APR was identified at the dosage used.

Characterization of cells expressing lipocalin-2 (LCN2) as a reporter.

Lipocalin-2 (LCN2), an effector molecule of the innate immune system that is small enough to be tagged as a reporter molecule, can be coupled with the ferric ion through a siderophore such as enterobactin (Ent). Mintbody (modification-specific intracellular antibody) can track a posttranslational protein modification in epigenetics. We constructed plasmids expressing the LCN2 hybrid of mintbody to examine the potential of LCN2 as a novel reporter for magnetic resonance imaging (MRI). Cells expressing the LCN2 hybrid of mintbody showed proper expression and localization of the hybrid and responded reasonably to Ent, suggesting their potential for in vivo study by MRI.

Longitudinal Fluctuations in Protein Concentrations and Higher-Order Structures in the Plasma Proteome of Kidney Failure Patients Subjected to a Kidney Transplant.

Using proteomics and complexome profiling, we evaluated in a year-long study longitudinal variations in the plasma proteome of kidney failure patients, prior to and after a kidney transplantation. The post-transplant period was complicated by bacterial infections, resulting in dramatic changes in the proteome, attributed to an acute phase response (APR). As positive acute phase proteins (APPs), being elevated upon inflammation, we observed the well-described C-reactive protein and Serum Amyloid A (SAA), but also Fibrinogen, Haptoglobin, Leucine-rich alpha-2-glycoprotein, Lipopolysaccharide-binding protein, Alpha-1-antitrypsin, Alpha-1-antichymotrypsin, S100, and CD14. As negative APPs, being downregulated upon inflammation, we identified the well-documented Serotransferrin and Transthyretin, but added Kallistatin, Heparin cofactor 2, and interalpha-trypsin inhibitor heavy chain H1 and H2 (ITIH1, ITIH2). For the patient with the most severe APR, we performed plasma complexome profiling by SEC-LC-MS on all longitudinal samples. We observed that several plasma proteins displaying alike concentration patterns coelute and form macromolecular complexes. By complexome profiling, we expose how SAA1 and SAA2 become incorporated into high-density lipid particles, replacing largely Apolipoprotein (APO)A1 and APOA4. Overall, our data highlight that the combination of in-depth longitudinal plasma proteome and complexome profiling can shed further light on correlated variations in the abundance of several plasma proteins upon inflammatory events.

Concentrations of selected immunological parameters in the serum and processing fluid of suckling piglets and the serum and colostrum of their mothers.

BACKGROUND: Blood sampling from neonatal piglets is related to multiple disadvantages. Therefore, a new, alternative matrix is required to assess piglets' early immune status efficiently. The present study aimed to assess the usefulness of processing fluid for determining selected piglets' immune parameters. 264 pigs - 31 sows, 146 male piglets, and 87 female piglets from commercial indoor farrow-to-finish pig herd were included in this study. 264 serum, 31 colostrum, and 146 processing fluid samples were collected. Serum was collected from all animals, colostrum was collected from sows, and processing fluid was collected from male piglets only. Using commercial ELISA tests, the concentration of various immunoglobulins, cytokines, and acute phase proteins was assessed in each matrix. Statistical analyses were employed to determine differences in the concentration of measured indices between piglets' serum and processing fluid and correlations in the concentration of tested indices between particular sets of matrices. RESULTS: Statistical analyses did not reveal significant differences in the IgG, IgA, IL-1ß, IL-4, IL-6, and IFN-γ concentration between piglets' serum and processing fluid (p > 0.05). A positive correlation (p < 0.05) regarding the concentration of some indices between processing fluid and samples collected from sows was also observed. CONCLUSIONS: Processing fluid can be considered a promising alternative to blood for assessing some immunological indices in piglets, such as IgG, IgA, IL-1ß, IL-4, IL-6, and IFN-γ, and, possibly, in the indirect assessment of some indices in lactating sows, including IgA, IL-1ß, IL-4, IL-6, IL-8, IFN-γ, or Pig-MAP.

Obesity and polycystic ovary syndrome influence on intestinal permeability at fasting, and modify the effect of diverse macronutrients on the gut barrier.

Women with the extremely prevalent polycystic ovary syndromegather multiple cardiovascular risk factors and chronic subclinical inflammation. Interactions between diet, adiposity, and gut microbiota modulate intestinal permeabilityand bacterial product translocation, and may contribute to the chronic inflammation process associated with the polycystic ovary syndrome. In the present study, we aimed to address the effects of obesity, functional hyperandrogenism, and diverse oral macronutrients on intestinal permeabilityby measuring circulating markers of gut barrier dysfunction and endotoxemia. Participants included 17 non-hyperandrogenic control women, 17 women with polycystic ovary syndrome, and 19 men that were submitted to glucose, lipid, and protein oral loads. Lipopolysaccharide-binding protein, plasma soluble CD14, succinate, zonulin family peptide, and glucagon-like peptide-2 were determined at fasting and after oral challenges. Macronutrient challenges induced diverse changes on circulating intestinal permeabilitybiomarkers in the acute postprancial period, with lipids and proteins showing the most unfavorable and favorable effects, respectively. Particularly, lipopolysaccharide-binding protein, zonulin family peptide, and glucagon-like peptide-2 responses were deregulated by the presence of obesity after glucose and lipid challenges. Obese subjects showed higher fasting intestinal permeabilitybiomarkers levels than non-obese individuals, except for plasma soluble CD14. The polycystic ovary syndromeexacerbated the effect of obesity further increasing fasting glucagon-like peptide-2, lipopolysaccharide-binding protein, and succinate concentrations. We observed specific interactions of the polycystic ovary syndromewith obesity in the postprandial response of succinate, zonulin family peptide, and glucagon-like peptide-2. In summary, obesity and polycystic ovary syndromemodify the effect of diverse macronutrients on the gut barrier, and alsoinfluence intestinal permeabilityat fasting,contributing to the morbidity of functional hyperandrogenism by inducing endotoxemia and subclinical chronic inflammation.

Lipopolysaccharide-binding protein in follicular fluid is associated with the follicular inflammatory status and granulosa cell steroidogenesis in dairy cows.

Metabolic stress and subsequent hepatic dysfunction in high-producing dairy cows are associated with inflammatory diseases and declining fertility. Lipopolysaccharide (LPS)-binding protein (LBP) is produced by hepatocytes and controls the immune response, suggesting that it is involved in the pathophysiology of inflammation-related attenuation of reproductive functions during metabolic stress. This study investigated the effect of LBP on the inflammatory status, oocyte quality, and steroidogenesis in the follicular microenvironment of dairy cows. Using bovine ovaries obtained from a slaughterhouse, follicular fluid and granulosa cells were collected from large follicles to evaluate the follicular status of metabolism, inflammation, and steroidogenesis. Cumulus-oocyte complexes were aspirated from small follicles and subjected to in vitro embryo production. The results showed that follicular fluid LBP concentrations were significantly higher in cows with fatty livers and hepatitis than in those with healthy livers. Follicular fluid LBP and LPS concentrations were negatively correlated, whereas LPS concentration showed a positive correlation with the concentrations of non-esterified fatty acids (NEFA) and ß-hydroxybutyric acid in follicular fluid. The blastulation rate of oocytes after in vitro fertilization was impaired in cows in which coexisting large follicles had high NEFA levels. Follicular fluid NEFA concentration was negatively correlated with granulosa cell expression of the estradiol (E2) synthesis-related gene (CYP19A1). Follicular fluid LBP concentration was positively correlated with follicular fluid E2 concentration and granulosa cell CYP19A1 expression. In conclusion, follicular fluid LBP may be associated with favorable conditions in the follicular microenvironment, including low LPS levels and high E2 production by granulosa cells.

Lipopolysaccharide binding protein resists hepatic oxidative stress by regulating lipid droplet homeostasis.

Oxidative stress-induced lipid accumulation is mediated by lipid droplets (LDs) homeostasis, which sequester vulnerable unsaturated triglycerides into LDs to prevent further peroxidation. Here we identify the upregulation of lipopolysaccharide-binding protein (LBP) and its trafficking through LDs as a mechanism for modulating LD homeostasis in response to oxidative stress. Our results suggest that LBP induces lipid accumulation by controlling lipid-redox homeostasis through its lipid-capture activity, sorting unsaturated triglycerides into LDs. N-acetyl-L-cysteine treatment reduces LBP-mediated triglycerides accumulation by phospholipid/triglycerides competition and Peroxiredoxin 4, a redox state sensor of LBP that regulates the shuttle of LBP from LDs. Furthermore, chronic stress upregulates LBP expression, leading to insulin resistance and obesity. Our findings contribute to the understanding of the role of LBP in regulating LD homeostasis and against cellular peroxidative injury. These insights could inform the development of redox-based therapies for alleviating oxidative stress-induced metabolic dysfunction.

Noninvasive Markers of Inflammation and Protein Loss Augment Diagnosis of Pediatric Celiac Disease.

INTRODUCTION: Circulating tissue transglutaminase immunoglobulin A concentration is a sensitive and specific indicator of celiac disease, but discrepancies between serologic and histologic findings occur. We hypothesized that fecal markers of inflammation and protein loss would be greater in patients with untreated celiac disease than in healthy controls. Our study aims to evaluate multiple fecal and plasma markers in celiac disease and correlate these findings with serologic and histologic findings as noninvasive means of evaluating disease activity. METHODS: Participants with positive celiac serologies and controls with negative celiac serologies were prospectively enrolled before upper endoscopy. Blood, stool, and duodenal biopsies were collected. Concentrations of fecal lipocalin-2, calprotectin, and alpha-1-antitrypsin and plasma lipocalin-2 were determined. Biopsies underwent modified Marsh scoring. Significance was tested between cases and controls, modified Marsh score and tissue transglutaminase immunoglobulin A concentration. RESULTS: Lipocalin-2 was significantly elevated in the stool ( P = 0.006) but not the plasma of participants with positive celiac serologies. There was no significant difference in fecal calprotectin or alpha-1 antitrypsin between participants with positive celiac serologies and controls. Fecal alpha-1 antitrypsin >100 mg/dL was specific, but not sensitive for biopsy-proven celiac disease. DISCUSSION: Lipocalin-2 is elevated in the stool but not the plasma of patients with celiac disease suggesting a role of local inflammatory response. Calprotectin was not a useful marker in the diagnosis of celiac disease. While random fecal alpha-1 antitrypsin was not significantly elevated in cases compared with controls, an elevation of greater than 100 mg/dL was 90% specific for biopsy-proven celiac disease.

Serum vitamin D metabolite and acute-phase protein concentrations are frequently abnormal in a cohort of hospitalized dogs and cats.

OBJECTIVE: To determine whether serum 25-hydroxyvitamin D (25[OH]D) and 1,25-dihydroxyvitamin D (1,25[OH]2D) concentrations are associated with survival and negatively correlate with acute-phase protein (APP) concentrations in ill dogs and cats admitted to nursing care units. ANIMALS: Client-owned dogs (n = 79) and cats (16) admitted to 2 academic veterinary hospital nursing care units. METHODS: A prospective cohort study was conducted between August 12, 2019, and October 26, 2021. A diagnostic laboratory measured 25(OH)D, 1,25(OH)2D, and haptoglobin (HPT) in dogs and cats; C-reactive protein (CRP) in dogs; and serum amyloid A (SAA) in cats. Serum was collected within 12 hours of admission. Illness severity (acute patient physiologic and laboratory evaluation [APPLEfast]) scores and survival data were recorded. RESULTS: Serum 25(OH)D concentrations were in the deficient range for 22 of 79 dogs and 2 of 16 cats. There were no associations between serum analyte concentrations (25[OH]D, 1,25[OH]2D, and APP) or APPLEfast score and survival in dogs or cats. In dogs, HPT was negatively correlated with 25(OH)D (P = .002; r = -0.34) and 1,25(OH)2D (P = .012; r = -0.28), while CRP was positively correlated with HPT (P = .001; r = 0.32) and APPLEfast score (P = .014; r = 0.16). In cats, 1,25(OH)2D was negatively correlated with APPLEfast scores (P = .055; r = -0.49) and SAA was positively correlated with HPT (P = .002; r = 0.73). CLINICAL RELEVANCE: Serum 25(OH)D or 1,25(OH)2D was not associated with survival in our hospitalized patient population. Relationships between APP and serum vitamin D metabolites with APPLEfast scores in cats warrant further investigation as illness severity biomarkers.

The acute phase reactant orosomucoid-2 directly promotes rheumatoid inflammation.

Acute phase proteins involved in chronic inflammatory diseases have not been systematically analyzed. Here, global proteome profiling of serum and urine revealed that orosomucoid-2 (ORM2), an acute phase reactant, was differentially expressed in rheumatoid arthritis (RA) patients and showed the highest fold change. Therefore, we questioned the extent to which ORM2, which is produced mainly in the liver, actively participates in rheumatoid inflammation. Surprisingly, ORM2 expression was upregulated in the synovial fluids and synovial membranes of RA patients. The major cell types producing ORM2 were synovial macrophages and fibroblast-like synoviocytes (FLSs) from RA patients. Recombinant ORM2 robustly increased IL-6, TNF-α, CXCL8 (IL-8), and CCL2 production by RA macrophages and FLSs via the NF-κB and p38 MAPK pathways. Interestingly, glycophorin C, a membrane protein for determining erythrocyte shape, was the receptor for ORM2. Intra-articular injection of ORM2 increased the severity of arthritis in mice and accelerated the infiltration of macrophages into the affected joints. Moreover, circulating ORM2 levels correlated with RA activity and radiographic progression. In conclusion, the acute phase protein ORM2 can directly increase the production of proinflammatory mediators and promote chronic arthritis in mice, suggesting that ORM2 could be a new therapeutic target for RA.

Can neutrophil gelatinase-associated lipocalin be a novel and efficient marker to predict the clinical course of acute pancreatitis?

OBJECTIVE: This study aimed to determine the value of serum Neutrophil Gelatinase-Associated Lipocalin (NGAL) levels to predict the severity of the disease and to identify its correlation with White Blood Cell (WBC), C-reactive protein (CRP), and high-sensitivity C-reactive protein (hs-CRP) levels in acute pancreatitis (AP). PATIENTS AND METHODS: The study sample included 86 AP-diagnosed patients in the study group and 77 age- and gender-matched healthy volunteers with no comorbidity in the control group. The WBC, CRP, hs-CRP, and NGAL levels were examined at the time and 24 hours after diagnosis. RESULTS: Between the control group and the study group, a significant difference with and without necrosis in terms of NGAL averages (p=0.003) at the time of admission was observed. The mean level of the 24th-hour NGAL in the study group with necrosis (132.7±11.7 ng/ml) was found to be higher than the mean of the 24th-hour NGAL (117.5±22.6 ng/ml) in the study group without necrosis (p=0.032). Additionally, a significant difference was observed between the control group and the study group with and without necrosis in terms of CRP averages evaluated at admission. When the correlation of NGAL levels with WBC, CRP, and hs-CRP levels at the admission (r=0.224, p=0.038) and at the 24th h (r=0.389, p<0.001) are evaluated, weak correlations between NGAL and WBC levels were identified, but no correlation between NGAL and CRP and hs-CRP levels were observed. CONCLUSIONS: The usability of serum NGAL levels to predict the development of necrotizing pancreatitis in the early period was evaluated. Serum NGAL levels were found to be higher in the study group than in the control group, but there was no statistically significant difference between the mean values of 0th and 24th h NGAL values in any of the groups with/without pancreatic necrosis and the total study group was observed. More research is needed on the subject, with larger sampling sizes.

LCN2: Versatile players in breast cancer.

Lipocalin 2 (LCN2) is a secreted glycoprotein that is produced by immune cells, including neutrophils and macrophages. It serves various functions such as transporting hydrophobic ligands across the cellular membrane, regulating immune responses, keeping iron balance, and fostering epithelial cell differentiation. LCN2 plays a crucial role in several physiological processes. LCN2 expression is upregulated in a variety of human diseases and cancers. High levels of LCN2 are specifically linked to breast cancer (BC) cell proliferation, apoptosis, invasion, migration, angiogenesis, immune regulation, chemotherapy resistance, and prognosis. As a result, LCN2 has gained attention as a potential therapeutic target for BC. This article offered an in-depth review of the advancement of LCN2 in the context of BC occurrence and development.

Neutrophil Gelatinase-Associated Lipocalin in Peritoneal Dialysis-Related Peritonitis: Correlation with White Blood Cells over Time and a Possible Role as the Outcome Predictor.

INTRODUCTION: The present study aimed to monitor peritoneal neutrophil gelatinase-associated lipocalin (pNGAL) during peritonitis episodes and to enhance its diagnostic value by evaluating pNGAL at scheduled times in parallel with white blood cell (WBC) count. In addition, we investigated possible correlations between pNGAL and the etiology of peritonitis, evaluating it as a possible marker of the clinical outcome. METHODS: Twenty-two patients with peritoneal dialysis (PD)-related peritonitis were enrolled. Peritonitis was divided into Gram-positive, Gram-negative, polymicrobial, and sterile. WBC count and neutrophil gelatinase-associated lipocalin (NGAL) in PD effluent were measured at different times (days 0, 1, 5, 10, 15, and/or 20 and 10 days after antibiotic therapy discontinuation). NGAL was measured by standard quantitative laboratory-based immunoassay and by colorimetric NGAL dipstick (NGALds) (dipstick test). RESULTS: We found strong correlations between peritoneal WBC, laboratory-based NGAL, and NGALds values, both overall and separated at each time point. On day 1, we observed no significant difference in WBC, both NGALds (p = 0.3, 0.9, and 0.2) between Gram-positive, Gram-negative, polymicrobial, and sterile peritonitis. No significant difference has been found between de novo versus relapsing peritonitis for all markers (p > 0.05). We observed a parallel decrease of WBC and both NGAL in patients with favorable outcomes. WBC count and both pNGAL resulted higher in patients with negative outcomes (defined as relapsing peritonitis, peritonitis-associated catheter removal, peritonitis-associated hemodialysis transfer, peritonitis-associated death) at day 10 (p = 0.04, p = 0.03, and p = 0.05, respectively) and day 15 (p = 0.01, p = 0.04, and tendency for p = 0.005). There was a tendency toward higher levels of WBC and NGAL in patients with a negative outcome at day 5. No significant difference in all parameters was proven at day 1 (p = 0.3, p = 0.9, p = 0.2) between groups. CONCLUSION: This study confirms pNGAL as a valid and reliable biomarker for the diagnosis of PD-peritonitis and its monitoring. Its trend is parallel to WBC count during peritonitis episodes, in particular, patients with unfavorable outcomes.