Early Identification of Fungal and Mycobacterium Infections in Pulmonary Granulomas Using Metagenomic Next-Generation Sequencing on Formalin fixation and paraffin embedding tissue

Background The purpose of the study is to assess the etiology detection ability of Metagenomic Next-Generation Sequencing (mNGS) on formalin fixation and paraffin embedding (FFPE) tissue from postoperative biopsy specimens.Methods We prospectively enrolled specimens from patients undergone surgery biopsy due to undefinite diagnosis and pathologically indicated granulomatous lesions. FFPE tissues were tested by mNGS and histopathology. The etiology detection rate of mNGS was calculated and compared with histopathology..Results Among the 69 cases eventually included, 41 (59.42%) were diagnosed with infectious granuloma. The overall fungi and mycobacteria etiology detection rates of mNGS in granuloma lesions was 87.80% (36/41). The mNGS increased the detection rate by 68.29% (28/41) compared with histopathology, the difference was statistically significant (χ2 = 28.97, P = 0.00). The detection rates of mNGS in fungal infections (12/12,100%) and in mycobacterium infections (22/27, 81.48%) were significant higher than those of histopathology (8/12, 66.67% and 0/27, 0.00%; both P = 0.00). Two (2/2.100%) cases of co-infection were detected at one time by mNGS. All mNGS-based clinical decisions were made within 2 days.Conclusions The mNGS could accurately and quickly detect fungi and mycobacteria in FFPE specimens from postoperative granuloma specimens and identify the pathogens to the species level.Clinical Trials Registration China Clinical Trial Registry ChiCTR2000035464