Serum maternal hepcidin levels 3 days after delivery are higher compared to those measured at parturition.

AIM: Our aim was to investigate the levels of hepcidin at parturition and 3 days after delivery and to relate hepcidin levels to parameters of iron homeostasis. MATERIALS AND METHODS: We measured hepcidin levels with mass spectrometry in serum samples of 38 term pregnant women taken just prior to and 3 days after vaginal delivery (n = 23) or cesarean section (CS) (n = 15). Hepcidin levels were related to iron homeostasis parameters and interleukin (IL)-6 levels. Parameters measured before and after delivery were compared with the Wilcoxon test. RESULTS: Serum iron levels (median, interquartile range) decreased (14.3, 9.6-21.1 vs. 8.9, 6.8-11.5 µmol/L, P < 0.01), while hepcidin levels increased (2.73, 2.2-3.45 vs. 10.62, 6.70-15.89 µg/L, P < 0.01) by the third day after parturition compared to those measured before delivery. IL-6 levels were comparable before and after delivery. No direct association between serum hepcidin and iron homeostasis parameters or IL-6 levels was found. CONCLUSIONS: Factors triggering hepcidin synthesis dominate 3 days after delivery. Studies are needed to assess the contribution of hepcidin to iron homeostasis during the periparturition period.

[Increased hepcidin levels three days after gynecological interventions]. / Emelkedett hepcidinszint nogyógyászati mutéteket követo harmadik napon.

UNLABELLED: Hepcidin is an endogenous substance that inhibits iron absorption and plasma iron levels. Due to technical reasons its levels are not routinely assessed and data regarding its clinical relevance are limited. We analyzed the alteration of hepcidin levels following gynecological interventions. Hepcidin levels were determined by mass spectrometry, along with the levels of interleukin-6, the main inductor of hepcidin with ELISA in 17 women undergoing gynecological intervention just prior to and three days after the surgery. The results were related to iron homeostasis parameters. A decrease in serum iron (median, interquartile range) (17.85 [15.25-24.9] versus 10.1 [7.6-15.0] µmol/l, p<0.01) and transferrin levels (60.3 [55.93-67.18] versus 53.1 [49.7-60.0], p< 0.01) µmol/l, simultaneously with an increase in hepcidin (2.75 [2.24-3.51] versus 8.01 [6.8-9.67] µg/l, p<0.01) and interleukin-6 levels (ND = not detected) (ND [ND - 2.2] versus 8.15 [2.31-12.86], p<0.01). CONCLUSION: As with other acute phase proteins postoperative hepcidin levels dramatically increase, simultaneously with other changes in iron homeostasis. These results indicate a possible causative relationship between increased hepcidin and decreased iron levels. In clinical practice, determination of hepcidin levels may be indicated for characterization and, possibly, prediction of postoperative iron homeostasis. However, measurement of hepcidin level in clinical practice is unlikely in the near future due to the lack of available kits for routine clinical laboratories.

Analysis of biological fluids by direct combination of solid phase extraction and desorption electrospray ionization mass spectrometry.

A novel, solid phase extraction (SPE)-based sample preparation method was developed for desorption electrospray ionization (DESI) mass spectrometry. Conventional SPE sample preparation was followed by a custom elution procedure. The eluate was evaporated from the closing frit of the cartridge using a gas jet. Thus the analyte was concentrated on the surface of the frit, which is ideal for DESI analysis. Application of the above SPE protocol allowed the concentration of the analyte content of up to 1 L liquid sample into a 1 mm diameter circular spot. The sample preparation procedure can improve the overall sensitivity of the method by up to 6 orders of magnitude if the sample volume is sufficient. The device has been tested using aqueous solutions of Rhodamine 116; the limit of detection was comparable to the LOD of electrospray analysis. Methodology was tested for drug monitoring applications in human serum. Levels of Cyclosporine A were determined using a 0.1 mL serum sample. Dynamic range of the method exceeded 3 orders of magnitude; the detection limit was below the therapeutic serum concentration of the drug.

Selective detection of specific protein-ligand complexes by electrosonic spray-precursor ion scan tandem mass spectrometry.

A novel mass spectrometric method for the selective detection of specific protein-ligand complexes is presented. The new method is based on electrosonic spray ionization of samples containing protein and ligand molecules, and mass spectrometric detection using the precursor ion scanning function on a triple quadrupole instrument. Mass-selected intact protein-ligand complex ions are subjected to fragmentation by means of collision-induced dissociation in the collision cell of the instrument, while the second mass analyzer is set to the m/z of protonated ligand ions or their alkali metal adducts. The method allows for the detection of only those ions which yield ions characteristic of the ligand molecules upon fragmentation. Since the scan range of first analyzer is set well above the m/z of the ligand ion, and the CID conditions are established to permit fragmentation of only loosely bound, noncovalent complexes, the method is specific to the detection of protein-ligand complexes under described conditions. Behavior of biologically specific and nonspecific complexes was compared under various instrumental settings. Parameters were optimized to obtain maximal selectivity for specific complexes. Specific and nonspecific complexes were found to show markedly different fragmentation characteristics, which can be a basis for selective detection of complexes with biological relevance. Preparation of specific and nonspecific complexes containing identical building blocks was attempted. Complex ions with identical stoichiometry but different origin showed the expected difference in fragmentation characteristics, which gives direct evidence for the different mechanism of specific versus nonspecific complex ion formation.