Changed Profile of Serum Transferrin Isoforms in Primary Biliary Cholangitis

The Association of Serum Profile of Transferrin Isoforms with COVID-19 Disease Severity

Background/Objective: Bearing in mind the relationship of transferrin (TRF) microheterogeneity with the biological activity of its isoforms, we propose, in this study, to determine the association of the profile of TRF isoforms with COVID-19 disease severity and to compare this profile to the profiles of other diseases. Methods: The disease group consisted of 96 patients from whom blood was collected twice, upon admission to the ward and after treatment (on average on the ninth day). TRF isoforms were separated by capillary electrophoresis. The analysis included disease severity, cytokine storm, comorbidities, patient survival, oxygen therapy, and modified early warning scores (MEWSs). Results: The concentration of 5-sialoTRF was higher in patients compared to controls at the beginning and during COVID-19 treatment. The concentration of this isoform varies with the severity of disease and was higher in critical patients than those with a moderate condition. Additionally, the level of 5-sialoTRF was lower and the level of 4-sialoTRF was higher in patients with comorbidities than that in patients without them. The concentration of 5-sialoTRF was lower and the concentration of 4-sialoTRF was higher in surviving patients than in non-surviving patients. There were no statistical changes in TRF isoforms according to presence of cytokine storm, MEWS, and oxygen therapy. Conclusions: We conclude that the profile of TRF isoforms in COVID-19 patients differs from that in other diseases. An increase in the concentration of a sialic acid-rich isoform, 5-sialoTRF, may be a compensatory mechanism, the goal of which is to increase oxygen delivery to tissues and is dependent on the severity of the disease. Additionally, the concentration of 5-sialoTRF may be a prognostic marker of the survival of COVID-19 patients.

The Serum Profile of Transferrin Isoforms in Pancreatitis

Total transferrin concentration changes in acute-phase reactions. Additionally, the alteration of transferrin glycosylation in inflammations can occur. The aim of this study is to evaluate the effect of pancreatitis on the serum profile of transferrin isoforms. The tested groups consisted of 84 patients with acute pancreatitis and 42 patients with chronic hepatitis. Transferrin isoforms were analyzed by capillary electrophoresis on a MINICAP electrophoretic system (Sebia, France). There was a significant decrease in the concentration of pentasialotransferrin in both acute and chronic pancreatitis, and a significant increase in tetrasialotransferrin in the acute pancreatitis group when compared to the control group. There were no significant changes in transferrin isoforms between the acute and chronic pancreatitis groups, and between the edematous and necrotizing forms of the disease. Considering the etiology of acute pancreatitis, we noticed higher values of bile acids and γ-glutamyltransferase in acute pancreatitis of alcoholic etiology than that in pancreatitis of other etiologies. In conclusion, the alterations in transferrin isoform profile in acute and chronic pancreatitis are not organ specific. Because similar changes were observed in hepatitis, we can conclude that the serum profile of transferrin isoforms is involved in the pathogenesis of the disease.

Increased sensitivity of gp210 autoantibody detection using a newly designed gp210 antigen

OBJECTIVES

The detection of autoantibody to glycoprotein 210 (gp210 Ab) against a 15 amino-acid peptide epitope by enzyme-linked immunosorbent assay (ELISA) has been widely used in the diagnosis of primary biliary cholangitis (PBC). However, this small peptide antigen presents spatial limitations for antibody access, which reduces the sensitivity of autoantibody detection. A recombinant gp210 antigen was constructed for increased sensitivity in antibody detection is described here.

METHODS

The gp210 C terminal 18 amino acid coding sequence was ligated to the modified C-terminal 108 amino acid coding sequence of human serum albumin (mHSA108) and produced as a recombinant gp210 antigen mHSA108-gp210-C18. Measurements of gp210 Ab using the gp210 C-terminal 25 amino acid peptide (gp210-C25) and mHSA108-gp210-C18 by in-house ELISA were compared. ELISAs with mHSA108-gp210-C18 and commercial INOVA kit for gp210 Ab detection were also compared in PBC patients and healthy controls. The correlation between the two assays was analyzed and their efficiency in diagnosing was compared.

RESULTS

Of 86 PBC samples, 35 (40.70%) and 44 (52.33%) positive samples were detected for anti-gp210 Ab using gp210-C25 and mHSA108-gp210-C18, respectively. Of 252 samples from PBC, 114 (45.24%) were positive for mHSA108-gp210-C18 ELISA whereas 94 (37.3%) for commercial ELISA (INOVA). All positive samples detected with commercial ELISA kit were also tested positive in mHSA108-gp210-C18 ELISA. Among 374 patients with other autoimmune diseases, anti-gp210 Ab were detected by mHSA108-gp210-C18 ELISA in 0.95% systemic lupus erythematosus (SLE) patients (2/210), 13.04% rheumatoid arthritis (RA) patients (13/97), and 1.47% of Sjögren's Syndrome (SS) patients (1/67).

CONCLUSIONS

Compared to the gp210 peptide antigen, the sensitivity of the ELISA system using mHSA108-gp210-C18 antigen was improved. The novel gp210 antigen could be useful for screening patients known to be at increased risk of developing PBC.

Pediatric Liver Disease Patients and Secondary Glycosylation Abnormalities

Background: Isoelectric focusing (IEF) of serum transferrin (Tf) is still the method of choice for diagnosis of congenital disorders of glycosylation (CDG). An abnormal glycosylation is also a known phenomenon in adult liver disease patients. The aim of this study was to characterize glycosylation disturbances in pediatric patients with primary liver disease. However, there are no reports of this phenomenon in children. Materials and Methods: Between 1995 and 2019, circa 2,000 serum Tf isoform analyses have been performed in children with primary liver diseases; some of them underwent subsequent analyses. We enrolled in this study 19 patients who developed an acute liver injury (ALI)/failure (ALF) or exhibited a chronic liver disease (CLD) and were evaluated and listed for liver transplantation (LTx) or had just undergone this procedure, and secondary abnormal serum Tf isoform profile. Results: Among 12 patients with ALI/ALF, 10 had an increased percentage of asialo-, monosialo-, and disialo-Tf isoforms. All patients with CLD had an increased percentage of asialo- and monosialo-Tf isoform. Two patients diagnosed with recurrent ALF had very specific serum Tf profile with a huge increase in the asialo- and monosialo-Tf isoform. On follow-up analyses (available in some patients), serum Tf IEF profile normalized in parallel to normalization of liver function tests, spontaneously or during treatment, including glucocorticosteroids in AIH, LTx in CLD. Conclusions: All pediatric patients with primary liver disease had increased asialo-Tf as well as monosialo-Tf isoforms. None of them had elevated percentage of trisialo-Tf isoform.