Diagnostic Value And Clinical Application Of Metagenomic Next-generation Sequencing In Invasive Pulmonary Aspergillosis

Background:In recent years,the incidence and mortality of invasive pulmonary aspergillosis(Invasive Pulmonary Aspergillosis,IPA)have been increasing year by year,which puts forward higher requirements for the rapid and accurate diagnosis of IPA.Traditional fungal culture,(1,3)-β-D-glucan(G)test and galactomannan(GM)test have some limitations.Metagenomic next generation sequencing(mNGS),as a new detection technology,has good sensitivity,short time consumption,can detect pathogens without bias,and has certain advantages in the diagnosis of difficult and critical infectious diseases.Objective:The diagnostic efficacy of mNGS was compared with that of traditional fungal culture,G test and GM test in the diagnosis of IPA.To explore the advantages and limitations of mNGS in the diagnosis of IPA.Methods:In our hospital to carry out a single center prospective study,analysis in March 2018 to March 2020,66 cases of Pulmonary and Critical Care Medicine of IPA and 70 patients with the IPA,collect the patient’s basic information,history,chest imaging data,laboratory examination,etc.,before to return patients treated in sputum,bronchoalveolar lavage fluid(Bronchoalveolar lavage fluid,BALF),blood and other specimens,do fungi cultivation,G test,GM test and mNGS detection,according to the patient’s host factors,clinical features,chest radiographic data,laboratory examination,treatment effect,to formthe final diagnosis.Through statistical analysis,baseline data and chest CT imaging findings of patients in the two groups were compared to compare the diagnostic efficacy of fungal culture,G test,GM test and mNGS test,and IPA patients were divided into groups to compare the diagnostic efficacy of fungal culture,G test,GM test and mNGS test in patients treated with anti Aspergillus.Results:A total of 136 patients(66 in the IPA group and 70 in the non-IPA group)were enrolled.There were no statistical differences in age,sex ratio,number of specimens and general data between IPA group and non-IPA group(P > 0.05).There was no statistical difference between IPA group and non-IPA group in basic diseases(P > 0.05).There were no significant differences in inflammatory indexes such as white blood cell count,neutrophil absolute value,C-reactive protein and procalcitonin(P > 0.05).There was no significant difference in tumor necrosis factorα,IL-6,IL-8 and IL-10(P > 0.05).IL-2R in IPA group was significantly higher than that in non-IPA group,with statistical difference(P < 0.05).The results of chest imaging comparison showed that there were multiple lesions in IPA group,which were mainly lump-shaped.The lesions were irregular in shape,mostly distributed in different lobes,and the main features were "halo sign" and "crescent sign"(P < 0.05).In the non-IPA group,the lesions were mostly single,with solid morphology,smooth edges,unilobar distribution and patchy features(P < 0.05).There were no significant differences between IPA group and non-IPA group in lesion morphology,burr like edge,"void sign" and "bronchial air sign" of consolidation(P > 0.05).In 66 patients with IPA,the sensitivity of mNGS was 53.03%,which was higher than that of traditional fungal culture method(27.27%),G test(31.82%)and GM test(34.84%).The sensitivity of mNGS(69.56%)was higher than that of traditional fungal culture method(36.96%),G test(41.30%)and GM test(45.65%)in 46 secretion etiological specimens.There was no significant difference between the sensitivity of MNGS and that of traditional fungal culture method(5.00%),G test(10.00%)and GM test(10.00%)in 20 serological specimens(P > 0.05).The sensitivity of fungal culture combined with G test,GM test and mNGS was 69.70%,and the specificity was97.14%,which was better than any of the other methods for detecting different specimens.The sensitivity of fungi culture,G test,GM test and mNGS in 32 patients without anti-Aspergillus treatment group was significantly higher than that in 34 patients with anti-Aspergillus treatment group(P < 0.05).The sensitivity of multiple methods combined detection was significantly higher than that of single detection method.There was no statistical difference in the number of cured,effective,improved and ineffective cases between IPA group and non-IPA group(P > 0.05).Conclusions:mNGS is better than traditional methods in diagnosing IPA,and it is better in alveolar lavage fluid and bronchial secretions,and it is still valuable in the treatment of patients with Aspergillus.Combined mNGS and other traditional methods can improve the diagnostic rate of IPA.