The Clinical Features And The Expression Of MiRNA492 In Peripheral Blood Of Children With Mycoplasma Pneumoniae Pneumonia In Suzhou Area

Objective:.1.To analyze the clinical feature of mycoplasma pneumoniae pneumonia of children in Suzhou and provide relevant information for clinical treatment.2.To investigate the expression of miRNA492 in peripheral blood of MPP and the function of miRNA492 in mycoplasma infection.Methods:1.Analyze the clinical feature of 200 children with mycoplasma pneumoniae pneumonia(MPP group)in Children's Hospital Affiliated to Soochow University from March 2014 to February 2016.2.27 cases of healthy children were collected as control group(NC group)in the same period.The laboratory results,distribution of T-lymphocyte,immunoglobulin levels of MPP children were compared with those of healthy children.3.23 cases of hospitalized children with Mycoplasma pneumoniae pneumonia(MPP group)were collected from March 2014 to June 2015 in Children's Hospital Affiliated to Soochow University.20 cases of healthy children were collected as control group(NC group)in the same period.Real-time quantitative PCR(RT-qPCR)was chosen to detect the expression of miRNA492 which up-regulated more than 2 folds.The target genes of miRNA492 were predicted by biological software.4.THP-1 cells were stimulated with the lipid-associated membrane proteins(LAMPs)at different times.And the expressions of miRNA492 from THP-1 cells were under the action of RT-qPCR assay.5.The expression of CD47,the target gene of miRNA492 were detected with real-time quantitative polymerase chain reaction(RT-qPCR)and flow cytometry inperipheral blood of MPP.6.The relativity of 13 differently expressed laboratory indicators and miRNA492 level in peripheral blood of MPP were analyzed.Results:1.The most common clinical feature of MPP children is cough(183 cases,91.5%),fever(149 cases,74.5%),lung rales(135 cases,67.5%),wheeze(42 cases,21%),nasal congestion and rhinorrhea(43 cases,21.5%),a few MPP children come up with cyanosis(4 cases,2%),polypnea(4 cases,2%),anhelation(4 cases,2%),difficult feeding(6 cases,3%),and gastrointestinal symptom(6 cases,3%).X-ray film of the chest showed patchy shadows in most MPP children.Incidences of wheeze,nasal congestion and rhinorrhea and lung rales were much higher in MPP children under 3 years old than others.Fever was more common and longer in children older than 1 year.2.The levels of WBC,Neut,PLT,CRP in MPP children were higher than children in NC group significantly(P<0.05).The levels of LDH,HBDH and CKMB increased more common in MPP children.The level of IgM in MPP group was higher than that in NC group significantly(P<0.05).CD3+,CD3+CD8+ and CD3-CD16+CD56+ were lower than those in NC group significantly(P<0.05).The CD3-CD19+ andCD19+CD23+ were higher than those in NC group significantly.3.The level of miRNA492 in peripheral blood of MPP children(2.052±0.497)were higher in that in NC group(1.000±0.210)significantly by RT-qPCR.Bioinformatics analysis shows CD47 may be one of the target protein of miRNA492.4.The mononuclear macrophages were stimulated with LAMPs or medium.The cells were collected 6 hours,12 hours and 24 hours after the stimulation with LAMPs for detection of miRNA492.The levels of miRNA492 were higher in LAMPs group at 6 hours and 12 hours after the stimulation than the control significantly(P<0.01).While the level of miRNA492 in LAMPs group at 24 hours after stimulation has no significant difference compare with the control(P>0.05).5.The expression of CD47 in peripheral blood mononuclear cells of MPP group(1.000±0.275)was lower than that in NC group significantly(0.506±0.152).6.No correlation was observed between miRNA492 level and the changed laboratory indicators(Neut,Lymph,CRP,AST,LDH,HBDH,PA,IgA,IgG,CD3+CD4+%,CD3-CD(16+56)+%,and CD19+CD23+% in MPP children.Conclusions:1.The most common clinical feature of MPP children in Suzhou area was cough and fever.Extrapulmonary manifestations were found in a few MPP children.Incidence of fever,lung rales,nasal congestion and rhinorrhea were different among MPP children of different ages.2.Disorder of humoral and cellular immunity were apparent in MPP children.3.MiRNA492 and CD47 may play a role in the pathogenesis of MPP.