The Application Of Metagenomic Next-generation Sequencing In The Diagnosis And Treatment Of Pulmonary Infection After DD Donor Kidney Transplantation

ObjectiveTo explore the application value of metagenomic next-generation sequencing technology in the diagnosis and treatment of pulmonary infection after deceased donor(DD)kidney transplantation.MethodsA retrospective collection of patients with pulmonary infection after kidney transplantation from DD donors who were admitted to the Department of Kidney Transplantation of the Second Affiliated Hospital of South China University from January 2018 to December 2020.Among them,45 patients who met the inclusion criteria were selected as the research objects.During the process,samples of the patient’s blood,sputum,and bronchoalveolar lavage fluid(BALF)were collected.Patients were divided into metagenomic next-generation sequencing(m NGS)group(20 cases)and control group(25 cases)according to whether m NGS was used to detect pathogenic microorganisms in body fluids(blood,sputum or BALF)of the patients.The m NGS group was simultaneously tested for pathogenic microorganisms in a traditional laboratory(e.g.Sutum culture,BALF culture,blood culture,1,3-β-D-glucan(1,3-Be-Ta-D-glucan(G)test,galactomannan(GM)test,cellular virus antibody Ig G/Ig M and DNA,antibody spectrum of respiratory pathogens,Mycoplasma pneumoniae,Chlamydia tests,etc.)and a m NGS test(body fluids tested by those two methods are identical),while the control group was only sent to traditional laboratory test.The basic information of patients,hospitalization days,hospitalization expenses,antimicrobial drug adjustment plans,traditional test results,m NGS results,disease outcome,and other data were collected.Results1.Basic information: There is no statistically significant difference between the m NGS group and the control group in comparison of the patient’s gender,age,and immune induction program(p>0.05).The average length of hospitalization and hospitalization expenses of patients in the m NGS group were lower than those in the control group,and the difference was statistically significant(p<0.01).2.Analysis of the detection of pathogenic microorganisms: Among the 45 patients with a lung infection after kidney transplantation from DD donors,pathogenic microorganisms were detected in 31 patients.The positive rate of pathogenic microorganisms was 68.89%,of which 12 were simple bacterial infections,accounting for 38.70%;3 cases were with a simple fungal infection,accounting for 9.68%;2 cases were infected with a simple viral infection,accounting for 6.45%;The infection of bacteria combined with fungi was the most common type of mixed infections.A total of 53 pathogenic microorganisms were detected in 31 patients.3.All the 20 patients in the m NGS group were tested by both m NGS and traditional microbial detection,and the difference between the two was tested by Mc Nemar,which was statistically significant(P =0.021).The results suggested that m NGS had a higher detection rate of pathogenic microorganisms than traditional microbial detection.The positive rate of m NGS in the diagnosis of fungi and viruses was significantly higher than that of traditional detection methods,and the difference was statistically significant.There was no significant difference between m NGS and conventional methods in the diagnosis of bacteria(P =0.111).The results of m NGS test in 10 patients were inconsistent with those of the traditional microorganism test.Among them,1 case was positive for traditional microorganism test but negative for m NGS test,which was considered as contamination.The other 9cases were positive for m NGS test but negative for the traditional microorganism test,which were considered as co-infection.There was no significant difference between m NGS and conventional microbial detection methods in the time required from sample submission to result return(P =0.11).4.Adjustment of antimicrobial drugs:17 cases were adjusted antimicrobial drug treatment according to the results of the m NGS,13 cases were adjusted the treatment plan according to the results of the traditional microbial test.Escherichia coli was detected in the traditional microorganisms of one patient,and the treatment plan was not changed in consideration of sample contamination,and the antimicrobial treatment plan was not adjusted in the other 14 patients with no pathogenic microorganisms detected.5.In the control group,13 patients changed their antimicrobial treatment regimens based on the results of traditional microbial testing.Among them,9 patients got better,4 died,and the case fatality rate was30.77%;17 patients in the m NGS group changed their antimicrobial treatment based on the results of m NGS,no patients died and the case fatality rate was 0%.The fatality rate difference between the two groups was statistically significant(p=0.026).It can be considered that the fatality rate of the m NGS group was significantly lower than that of the control group.ConclusionAmong patients with pulmonary infection after DD donor kidney transplantation,mixed infection was the most common infection type,and the pathogenic microorganisms were mainly bacteria.m NGS detection can improve the detection positive rate of pathogenic microorganisms,especially in the detection of fungi and viruses.The adjustment of antimicrobial therapy regimen based on m NGS results can shorten the hospitalization time and reduce the cost of hospitalizations well as the fatality rate.