Application Of Next-generation Sequencing In Bloodstream Infections In Patients With Hematologic Diseases

Objective:To explore the value of next-generation sequencing(NGS)in detecting bloodstream pathogens in patients with hematologic diseases.Method:50 patients with hematologic diseases suspected of bloodstream infection(BSI)in the Department of Hematology affiliated hospital of Chengde Medical College from July 2018 to July 2019 were collected.blood samples were collected for blood culture and NGS.Record blood culture and NGS results.In combination with clinical practice,if pathogenic microorganisms are cultured or detected,they are judged to be positive.The Mc Nemar test was used to compare the positive rates of blood culture and NGS.Results:1 Among the 50 patients,there were 28 males and 22 females,median age59 years,with procalcitonin(PCT)4.57 ± 1.76ng/ml and C-reactive protein(CRP)99.77 ± 9.30mg/l.Hematologic diseases distribution: 23 cases of Leukemia,8 cases of infectious cytopenia,6 cases of Multiple Myeloma,5cases of Myelodysplastic Syndromes,3 cases of Aplastic Anemia,1 case of Lymphoma,1case of autoimmune cytopenia,1case of drug-induced cytopenia,1 case of langerhans cell histiocytosis,1case of eosinophilia.2 Of the 50 patients,7 were non-bloodstream infection and 43 were bloodstream infection,of which 31 were primary bloodstream infection and 12 were secondary bloodstream infection.3 Among the 50 blood samples,18 kinds of bacteria and 2 kinds of fungi were detected in blood culture,and 32 strains of pathogenic bacteria wereisolated.30 bacteria,7 fungi and 7 viruses were detected by NGS,among which 22 bacteria and 4 fungi were clinically judged to be pathogenic,with a total of 54 strains.4 Of the 50 blood samples,26 were positive for both tests,13 were negative for blood culture and positive for NGS,4 were positive for blood culture and negative for NGS,and 7 were negative for both.The positive rate of NGS(78.0%)was higher than that of blood culture(60.0%),there was statistical significance between them(P=0.049,P<0.05).5 Blood culture and NGS were all negative in 11 patients with BSI after antibacterial treatment,and the reads of pathogenic bacteria disappeared or decreased in NGS.Conclusions:1 The pathogens detection rate of NGS was higher than that of blood culture.2 The type and quantity of pathogens detected by NGS were more than that in blood culture.3 NGS can quantitatively detect the DNA content of pathogen in samples,which is helpful for clinical monitoring of disease progression and evaluation of treatment effect.