Preliminary study on predictive indicators of disease severity in patients with influenza A (H1N1)

Objective To analyze the differences of peripheral blood transcriptome between mild and severe influenza A (H1N1) patients, and to find indicators for the assessment of disease severity. Methods A total of ten patients (five patients with mild disease and five patients with severe disease) diagnosed with H1N1 infection from January to May 2018 at Huashan Hospital, Fudan University in Shanghai were enrolled, and five healthy people were also enrolled as controls. The peripheral blood of patients was collected for transcriptome sequencing at the time when they were first diagnosed. Measurement data were compared using t test or Mann-Whitney U test. The count data were compared using Fisher exact test when appropriate. Data analysis of transcriptome predictions was performed using bioinformatics methods. Results The platelet counts were significantly different between mild and severe groups ((163.4±21.5 )×109/L vs (255.6±52.5)×109/L, t=3.636, P=0.007). There were no differences between the two groups in gender, age, white blood cell counts, neutrophil percentage, lymphocyte percentage and hemoglobin levels (all P>0.05). However, the average expression levels of matrix metalloproteinase (MMP) 8 and MMP9 in severe group (18.41 and 174.00, respectively) were both higher than those in mild group (2.33 and 22.91, respectively) and healthy control (1.43 and 34.65, respectively; all P<0.01). Conclusion MMP8 and MMP9 could be expected to serve as the molecular biological markers for predicting the disease severity in patients with influenza A (H1N1) infection. Key words: Influenza A virus, H1N1; Matrix metalloproteinase 8; Matrix metalloproteinase 9; RNA sequencing