Presence of hepcidin-25 in biological fluids: Bile, ascitic and pleural fluids

Antimicrobial peptides and proteins in human biological fluids

Antimicrobial peptides and proteins (AMPs) are endogenous compounds that have a direct antimicrobial effect on bacteria (e. g., by disrupting bacterial membranes), as well as on fungi and viruses. AMPs are the main component of the innate immunity of living organisms and are produced by both epithelial cells (skin cells, cells of respiratory tract, intestine, urinary and genital tracts) and cells of the immune system and are secreted into secretory fluids. AMPs can also act as chemoattractants for immunocompetent cells (neutrophils, monocytes, T lymphocytes, dendritic cells) in the inflammation site and affect the antigen presenting cells by modulating adaptive T cell immune responses. The representatives of the main 15 AMP classes, that we describe in this review, are the most studied group of the large pool of these compounds. We discuss their localization, expression, and concentration in various biofluids of humans under normal and pathological conditions.

Evaluation of Prognostic Factors of Severity in Acute Biliary Pancreatitis

Acute pancreatitis (AP) is an inflammatory disorder of the pancreas that, when classified as severe, is associated with high morbidity and mortality. Promptly identifying the severity of AP is of extreme importance for improving clinical outcomes. The aim of this study was to compare the prognostic value of serological biomarkers, ratios, and multifactorial scores in patients with acute biliary pancreatitis and to identify the best predictors. In this observational and prospective study, the biomarkers, ratios and multifactorial scores were evaluated on admission and at 48 h of the symptom onset. On admission, regarding the AP severity, the white blood count (WBC) and neutrophil-lymphocyte ratio (NLR), and regarding the mortality, the WBC and the modified Marshall score (MMS) showed the best predictive values. At 48 h, regarding the AP severity, the hepcidin, NLR, systemic inflammatory response index (SIRI) and MMS and regarding the mortality, the NLR, hepcidin and the bedside index for severity in AP (BISAP) score, showed the best predictive values. The present study enabled the identification, for the first time, of SIRI as a new prognostic tool for AP severity, and validated hepcidin and the NLR as better prognostic markers than C-reactive protein (CRP) at 48 h of symptom onset.

Salivary metals, age, and gender correlate with cultivable oral Candida carriage levels

Background: Little is known about the normal range of metal levels in unstimulated saliva, nor whether these might impact Candida carriage in healthy individuals. Both are important in determining which populations are at risk for candidiasis, as the availability of metal ions can influence the growth and pathogenesis of Candida albicans.

Objective: We quantified salivary metals of healthy individuals to determine the correlation with C. albicans oral colonization.

Design: Unstimulated whole saliva was collected from healthy adults and plated to determine fungal carriage, and metal content was measured using ICP-mass spectrometry (ICP-MS).

Results: Zinc was most abundant, followed by iron, copper, manganese, and nickel. Cultivable oral Candida carriage was found in 48% of people. Total protein levels did not differ in salivas from donors with or without carriage. However, innate fungicidal activity was increased in donors with carriage; correlations between levels of several metals were stronger in salivas with fungal carriage, indicating a shift in the oral environment. Concentrations of copper and manganese, as well as age and gender, were significantly predictive of carriage levels in a multiple regression model.

Conclusions: Salivary copper and manganese content along with age and gender could be used as a predictive metric for individuals that are more susceptible to Candida overgrowth.

The diagnostic value of neutrophil gelatinase-associated lipocalin and hepcidin in bacteria translocation of liver cirrhosis

OBJECTIVE

Bacterial translocation (BT) or bacterial DNA (bactDNA) translocation is a critical pathogenesis mechanism of spontaneous bacterial peritonitis. Studies of BT or bactDNA translocation are limited in humans. Neutrophil gelatinase associated lipocalin (NGAL) can efficiently distinguish bacterial and nonbacterial ascites in ascitic patients. Hepcidin is a useful marker of bacterial infection in the late-onset sepsis. However, the relationship between NGAL, hepcidin and BT was still unclear. In present study, the levels of NGAL, hepcidin and their relationship with BT or bactDNA translocation were investigated.

MATERIAL AND METHODS

Weekly doses of carbon tetrachloride (CCl4) were given to induce liver cirrhosis in Sprague-Dawley rats. Trypticase (blood) soy agars were used to culture bacteria. BactDNA was sequenced by ABIPRISM 310 automated sequencer. The levels of NGAL and hepcidin were assessed by ELISA. Receiver operating characteristic (ROC) curve was used to determine the cut-off values and compare the diagnostic performance of NGAL and hepcidin.

RESULTS

56 cirrhotic and 10 normal rats were included in this study. The levels of both two biomarkers were significantly higher in BT or bactDNA translocation group compared to non-translocation group. The area under ROC curve for the diagnosis of BT was 0.910 for serum NGAL, 0.858 for serum hepcidin and 0.940 for their combination, whereas that for the diagnosis of bactDNA translocation was 0.906 for NGAL, 0.779 for hepcidin and 0.950 for their combination, respectively. The combination of NGAL and hepcidin improved the ability to detect BT or bactDNA presence in MLNs and ascites.

CONCLUSION

BT and the presence of bactDNA in MLNs were observed in a rat cirrhotic model. Serum NGAL and hepcidin can serve as sensitive and specific tests for diagnosis of BT or bactDNA translocation. NGAL in combination with hepcidin can improve the accuracy of diagnosis.

Concentrations of preptin, salusins and hepcidins in plasma and milk of lactating women with or without gestational diabetes mellitus

This study was undertaken to ascertain whether human milk contains preptin, salusin-alpha (salusin-α) and -beta (salusin-β) and pro-hepcidin and hepcidin-25, and whether there are relationships between plasma and milk preptin, salusin-α and -β and pro-hepcidin and hepcidin-25 concentrations in lactating mothers with and without gestational diabetes mellitus (GDM). Blood was obtained from non-lactating women (n = 12), non-diabetic lactating women (n = 12), and GDM lactating women (n = 12). Colostrum, transitional milk, and mature milk samples were collected just before suckling from healthy and GDM lactating women. Peptides concentrations were determined by ELISA and EIA. Mammary gland tissues were screened immunohistochemically for these peptides. Women with GDM had significantly higher plasma and colostum preptin concentrations than healthy lactating women during the colostral and transitional milk period. Salusin-alpha and -beta levels in milk and plasma were lower in women with GDM. Salusin-α and -β were significantly lower in both plasma and colostrums of GDM than of healthy lactating women. Women with GDM had significantly higher colostum prohepcidin and hepcidin-25 concentrations than healthy lactating women during the colostral period. Plasma prohepcidin was also higher in women with GDM than in healthy lactating women during the colostral period, but plasma prohepcidin and hepcidin-25 levels decreased during mature milk period. Transitional milk pro-hepcidin and hepcidin-25 levels in women with GDM were higher than in healthy lactating women. All these results revealed that the mammary gland produces those peptides, which were present in milk at levels correlating with plasma concentrations.

Hepcidin is an antibacterial, stress-inducible peptide of the biliary system

BACKGROUND/AIMS

Hepcidin (gene name HAMP), an IL-6-inducible acute phase peptide with antimicrobial properties, is the key negative regulator of iron metabolism. Liver is the primary source of HAMP synthesis, but it is also produced by other tissues such as kidney or heart and is found in body fluids such as urine or cerebrospinal fluid. While the role of hepcidin in biliary system is unknown, a recent study demonstrated that conditional gp130-knockout mice display diminished hepcidin levels and increased rate of biliary infections.

METHODS

Expression and localization of HAMP in biliary system was analyzed by real time RT-PCR, in-situ hybridization, immunostaining and -blotting, while prohepcidin levels in human bile were determined by ELISA.

RESULTS

Hepcidin was detected in mouse/human gallbladder and bile duct epithelia. Biliary HAMP is stress-inducible, in that it is increased in biliary cell lines upon IL-6 stimulation and in gallbladder mucosa of patients with acute cholecystitis. Hepcidin is also present in the bile and elevated prohepcidin levels were observed in bile of primary sclerosing cholangitis (PSC) patients with concurrent bacterial cholangitis compared to PSC subjects without bacterial infection (median values 22.3 vs. 8.9; p = 0.03). In PSC-cholangitis subjects, bile prohepcidin levels positively correlated with C-reactive protein and bilirubin levels (r = 0.48 and r = 0.71, respectively). In vitro, hepcidin enhanced the antimicrobial capacity of human bile (p<0.05).

CONCLUSION

Hepcidin is a stress-inducible peptide of the biliary epithelia and a potential marker of biliary stress. In the bile, hepcidin may serve local functions such as protection from bacterial infections.