The following is a summary of “Application of metagenomic next-generation sequencing in optimizing the diagnosis of ascitic infection in patients with liver cirrhosis,” published in the May 2024 issue of Infectious Disease by Shi et al.

The potential of metagenomic next-generation sequencing (mNGS) for diagnosing ascites infection in patients with cirrhosis, as this technique is relatively new in this context.

Researchers conducted a retrospective study to assess the effectiveness of mNGS compared to conventional culture methods in diagnosing the cause of cirrhotic ascites while also evaluating the clinical impact of mNGS.

They analyzed diagnostic results, pathogen species, and clinical effects by comparing mNGS with conventional culture detection in 109 patients with ascites due to cirrhosis. The impact of mNGS on diagnosing and managing ascites infection in patients with cirrhosis was assessed. (mNGS = metagenomic next-generation sequencing)

The results showed that ascites cases consisted of three types, spontaneous bacterial peritonitis (SBP) (16/109, 14.7%), bacterascites (21/109, 19.3%), and sterile ascites (72/109, 66.1%). Of the 109 patients, 80 (73.4%) were in the ascites mNGS-positive group, and 29 (26.6%) were in the ascites mNGS-negative group. The mNGS method showed a significantly higher positive rate compared to traditional methods (73.4% vs. 28.4%, P<0.001), mNGS detected 43 bacterial strains, 9 fungal strains, and 8 viral strains, whereas culture methods detected only 14 bacterial strains and 3 fungal strains. 

Mycobacteria, viruses, and pneumocystis were exclusively detected by mNGS. The polymicrobial infection rate was higher with mNGS than the culture method (55% vs. 16%). The detection rate of pathogens was similar between the two methods when considering polymorphonuclear neutrophil (PMN) counts, with 87.5% (14/16) in the PMN ≥ 250/mm³ group and 72.0% (67/93) in the PMN < 250/mm³ group (P >0.05). Combining ascites PMN counts with mNGS assay diagnosed ascitic fluid infection (AFI) in 72 patients (66.1%), significantly higher than with the culture assay (33.9%) (P<0.05). Positive clinical effects were observed in 60 patients (55.0%) with the mNGS assay, leading to treatment adjustments in 40 patients (85.7%) and improving 48 patients. The coincidence rate between mNGS results and clinical findings was 75.0% (60/80).

Investigators found mNGS promising for diagnosing ascites infection in cirrhosis but interpreting results for antibiotic guidance requires further exploration.

Source: bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-024-09396-9