Value of MiR-155 in Prognostic Evaluation of Elderly Patients with Primary Immune Thrombocytopenia / 中国实验血液学杂志

OBJECTIVE@#To explore the value of has-microRNA-155 (miR-155) in peripheral blood mononuclear cells (PBMNC) in prognostic evaluation of elderly patients with primary immune thrombocytopenia (PITP).@*METHODS@#One hundred and thirty elderly PITP patients and 60 healthy volunteers in our hospital were selected. The relative expression level of miR-155 in PBMNC was detected by RT-PCR. Unconditional logistic multivariate regression analysis was used to analyze the relationship between miR-155 expression and prognosis of PITP patients, and Kaplan-Meier was further used to analyze the relationship between miR-155 and PITP recurrence.@*RESULTS@#The relative expression level of miR-155 in PBMNC of elderly PITP patients was significantly higher than that in healthy volunteers, and increased significantly with the severity of the disease (P＜0.05). The overall effective rate of elderly PITP patients with miR-155 low-expression was significantly higher than that in the patients with miR-155 high-expression (96.92% vs 72.31%) by after treatment with glucocorticoid. Multivariate analysis showed that miR-155 was an independent risk factor for PITP patients. Elderly patients with high expression of miR-155 showed a higher risk of recurrence.@*CONCLUSION@#miR-155 in PBMNC has a high accuracy for PITP diagnosis, and the elderly patients with high level of miR-155 show a poor prognosis and a higher risk of recurrence.

Serotype and virulence genes of Klebsiella pneumoniae isolated from mink and its pathogenesis in mice and mink.

In the study, 15 K. pneumoniae strains were isolated from the mink experiencing respiratory distress in mideastern Shandong province, China, and the prevalence of K. pneumoniae in the sampled mink was 11.9% (15/126). Fourteen (93.33%) of the 15 K. pneumoniae isolates were identified as serotype K2 and hypermucoviscosity phenotype. The 12 virulence-associated genes of the K. pneumoniae isolates were tested. The prevalence of the wabG gene for the isolates were 100% (15/15), the ureA gene 100% (15/15), the rmpA gene 93.33% (14/15), the aerobactin gene 93.33% (14/15), the uge gene 93.33% (14/15), the IucB gene 80% (12/15) and the ybtA gene 13.33% (2/15). But the other five genes, fim, iroNB, wcaG, alls and kfuBC, gave a negative PCR reaction in the 15 isolates, respectively. The animal experiments using K. pneumoniae-SD-12 and K. pneumoniae-SD-21 demonstrated that the serotype K2 was high virulence for mice and mink. These finding implied there exist potential threat that K. pneumoniae pathogens could transmit to human, especially the fur animal farm workers and residents lived near the fur animal farms. Therefore, the etiology and epidemiological surveillance of K. pneumoniae in mink should be strengthened for people's public health.

Intraspecies and interspecies transmission of mink H9N2 influenza virus.

H9N2 influenza A virus (IAV) causes low pathogenic respiratory disease and infects a wide range of hosts. In this study, six IAVs were isolated from mink and identified as H9N2 IAV. Sequence analysis revealed that the six isolates continued to evolve, and their PB2 genes shared high nucleotide sequence identity with H7N9 IAV. The six isolates contained an amino acid motif PSRSSR↓GL at the hemagglutinin cleavage site, which is a characteristic of low pathogenic influenza viruses. A serosurvey demonstrated that H9N2 IAV had spread widely in mink and was prevalent in foxes and raccoon dogs. Transmission experiments showed that close contact between H9N2-infected mink and naive mink, foxes and raccoon dogs resulted in spread of the virus to the contact animals. Furthermore, H9N2 challenge experiments in foxes and raccoon dogs showed that H9N2 IAV could infect these hosts. Virological and epidemiological surveillance of H9N2 IAV should be strengthened for the fur animal industry.

Molecular characterization of feline panleukopenia virus isolated from mink and its pathogenesis in mink.

Six feline panleukopenia viruses (FPV) were detected in the intestinal samples from the 176 mink collected in China during 2015 to 2016, named MEV-SD1, MEV-SD2, MEV-SD3, MEV-SD4, MEV-SD5 and MEV-SD6. The VP2 genes of the isolates shared 98.9%-100% identity with the reference sequences. The substitution of residue V300A in VP2 protein differentiates the isolates from the reference MEVs, and A300 is a characteristic of FPV. Furthermore, phylogenetic analysis of VP2 genes indicated that the six isolates were clustered into the same branch of all the reference FPVs. The NS1 genes of the isolates shared 98.2%-100% identity with the reference sequences. The NS1 genes of the six isolates and the three reference FPVs formed one unique evolutionary branch. To clarify the pathogenicity of the isolates, animal experiments were performed on healthy mink, using MEV-SD1. As a result, the morbidity of the inoculated animals was 100% and the mortality was as high as 38.9%. It was implied that the FPV infection caused a high morbidity and mortality in mink and the inoculation dose had an effect on pathogenicity of MEV-SD1 in mink.