Serum amyloid A and clusterin as potential predictive biomarkers for severe hand, foot and mouth disease by 2D-DIGE proteomics analysis

Association of the IRAK4 rs4251545 genetic polymorphism with severity of enterovirus-71 infection in Chinese children

INTRODUCTION

This study aimed to explore the association between the IRAK4 polymorphism rs4251545 and the severity of enterovirus 71 (EV71) infection in Chinese children.

METHODS

We analyzed the IRAK4 polymorphism rs4251545 in 617 EV71-infected patients and 410 controls using the improved multiplex ligation detection reaction. IRAK4 mRNA expression was tested by qRT-PCR. Serum concentrations of IL-6 and NF-κB were detected using ELISA.

RESULTS

The frequencies of the GA + AA genotype and A allele in the mild EV71 infection group and in the severe EV71 infection group were significantly higher than those in the normal control group. The frequency of the GA + AA genotype and A allele in severely infected EV71 patients was markedly higher than that in mildly infected EV71 patients. IRAK4 mRNA expression in mildly infected EV71 patients and severely infected patients was significantly higher than that in the control group. IRAK4 mRNA expression in GA + AA genotypes in both mild and severe EV71 infection groups was significantly higher than that in patients with the GG genotype. IL-6 concentration and the ratio of IL-6/NF-κB in severe EV71 cases were significantly lower in patients with the GA + AA genotype than in those with the GG genotype. The ratio of IL-6/NF-κB was distinctly higher in severely infected EV71 patients than in mildly infected and control subjects.

CONCLUSIONS

The IRAK4 polymorphism rs4251545 was associated with the susceptibility and severity of EV71 infection. The A allele is a susceptible factor in the development of severe EV71 infection in Chinese children.

Validation of serum apolipoprotein A1 in rabies virus-infected mice as a biomarker for the preclinical diagnosis of rabies

Rabies is a type of acute fetal encephalitis caused by rabies virus (RABV). While it becomes incurable after symptom onset, it can be prevented by post‐exposure prophylaxis (PEP) during the long incubation period. While preclinical diagnosis aids the appropriate PEP administration, it is mostly nonfeasible owing to the absence of viremia or a specific antibody response during the incubation period. Here, an attempt was made to identify a serum biomarker for the preclinical diagnosis of rabies. Using the serum from a mouse inoculated intramuscularly (i.m.) with 5 × 10⁵ focus‐forming units (FFU) of recombinant RABV expressing red firefly luciferase (1088/RFLuc) immediately before symptom onset, two‐dimensional differential gel electrophoresis was conducted, followed by mass spectrometry, and it was confirmed that apolipoprotein A1 (ApoA1) was up‐regulated. ELISA showed that the serum ApoA1 and specific antibody levels increased during the incubation period and on the day of symptom onset. Since a lower infectious dose can be used to induce the unstable and long incubation period generally observed in natural infection, the ApoA1 level in mice inoculated i.m. with 10³ FFU of 1088/RFLuc was examined by monitoring viral dynamics using in vivo imaging. The serum ApoA1 and specific antibody levels were up‐regulated in 50% and 58.3% of mice exhibiting robust RABV replication, respectively, but not in mice exhibiting weak RABV replication. In addition, it was reported that ApoA1 was found to be a biomarker for neuronal damage. Additional biomarker candidates will be needed for the effective preclinical diagnosis of rabies.

The Diagnostic and Therapeutic Value of the Detection of Serum Amyloid A and C-Reactive Protein in Infants with Rotavirus Diarrhea

Objective

This study explores the significance of serum amyloid A (SAA), C-reactive protein (CRP), and white blood cell (WBC) in the diagnosis and treatment of diarrhea in infants.

Methods

Specimens were collected from 126 children with diarrhea and 66 healthy children undergoing health examination. According to the results of stool culture and rotavirus (RV) antigen, these children were divided into three groups: rotavirus group (70 cases), bacterial infection (56 cases), and control groups (66 cases). On the fourth day of admission, children in the RV group underwent stool culture again. Based on the subsequent results, they were further divided into two groups, ie, no secondary bacterial infection and secondary bacterial infection groups. The levels of RV antigen, bacterial antigen, SAA, CRP, and WBC were detected in all children. Then, ROC curve analysis was performed to determine the diagnostic efficacy of SAA, CRP and WBC.

Results

The levels of SAA, CRP, and WBC for the RV group were lower than those of the bacterial infection group, but higher compared with the control group (P<0.05). The diagnostic efficacy of SAA was higher than that of CRP and WBC, with the area under the curve of 0.876, 0.803, and 0.765, respectively. The positive and negative predictive values, specificity, and sensitivity of SAA were slightly better compared with CRP and WBC. The SAA, CRP, and WBC levels of children with a bacterial infection in the RV group on the fourth and seventh days after admission were also significantly higher compared with children without bacterial infection.

Conclusion

Serum amyloid A, CRP, and WBC levels had a high value in the differential diagnosis of infantile diarrhea. As such, they can be used in the early diagnosis and curative efficacy assessment of children with diarrhea.

Exploration of vascular adhesion protein-1 expression in patients with conjunctivitis associated systemic lupus erythematosus using 2D-DIGE

Conjunctivitis associated systemic lupus erythematosus (caSLE) is a connective tissue autoimmune disease with a large spectrum of clinical manifestations. The disease may lead to ocular complications and in severe cases may be sight-threatening. This study investigated the expression of vascular adhesion protein-1 (VAP-1) in SLE patients with conjunctivitis and the relationship between VAP-1 and other proteins in the onset of the disease. Ten patients with caSLE (caSLE group) and 10 healthy volunteers (control group) were enrolled in the study, in order to evaluate the VAP-1 expression levels in blood. Protein expression profiling was performed with two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and analyzed with matrix-assisted laser desorption/deionization time-of-flight (MALDI-TOF) used in tandem with mass spectrometry. In the caSLE group, 8 proteins were expressed differenty compared with the control group: C-reactive protein, hemoglobin subunit β, VAP-1, A-albumin (AFAM), enolase and immunoglobulin heavy constant mu were upregulated; interferon regulatory factor-1 and serum amyloid A2 protein were downregulated. Western blotting results are consistent with the proteomics results, showing that in caSLE group VAP-1 expression is increased in comparison to the control group. VAP-1 protein participates in the inflammatory reaction in the form of amine oxidase, copper containing 3. Bioinformatics analysis suggested that VAP-1 protein could be used as a candidate protein for further study regarding its role as a potential protein marker for screening and effectively monitoring caSLE.

Proteomics analysis identified serum biomarkers for occupational benzene exposure and chronic benzene poisoning

The study aimed to find novel effect biomarkers for occupational benzene exposure and chronic benzene poisoning (CBP), which might also provide clues to the mechanism of benzene toxicity.We performed a comparative serological proteome analysis between healthy control workers with no benzene exposure, workers with short-term benzene exposure, workers with long-term benzene exposure, and CBP patients using 2D-DIGE and MALDI-TOF-MS. Two of the differentially expressed proteins were then selected to be validated by immune turbidimetric analysis.A total of 10 proteins were found to be significantly altered between different groups. The identified deferentially expressed proteins were classified according to their molecular functions, biological processes, and protein classes. The alteration of 2 important serum proteins among them, apolipoprotein A-I and transthyretin, were further confirmed.Our findings suggest that the identified differential proteins could be used as biomarkers for occupational benzene exposure and CBP, and they may also help elucidate the mechanisms of benzene toxicity.