Performance of the BIOFIRE® Filmarray Pneumonia Plus Panel for quantifiable bacterial targets compared to semiquantitative culture methods: A systematic review and meta-analysis

This study aimed to assess the association between bacterial loads as quantified by the BIOFIRE® Filmarray Pneumonia Plus Panel (FA-PP) and clinically significant bacterial cultures in different clinical settings, taking into account the type of sample processed and the bacterial targets detected. A comprehensive search was conducted of the PubMed, EMBASE, and Web of Science databases up to November 2024. Pooled odds ratios (ORs) for binned values in genome copies/ml (gc/ml)(10⁴, 10⁵, 10⁶, and ≥10⁷) and their respective 95% confidence intervals (95% CI) are reported throughout the study. Heterogeneity across studies was assessed using the I² statistic. Twenty-three observational studies comprising a total of 4581 patients and 5147 respiratory samples were finally included in the meta-analysis. Overall, pooled ORs for clinically significant culture results were 4.30 (95% CI, 2.53-7.31; P < 0.001) for ≥10⁷ gc/ml, 1.33 (95% CI, 0.70-2.56; P=0.39) for 10⁶, 0.42 (95% CI, 0.20-0.90; P=0.03) for 10⁵, and 0.1⁵ (95% CI, 0.07-0.37; P < 0.001) for 10⁴ gc/ml. Subgroup analyses conducted according to the type of respiratory sample, bacterial target, and hospital admission ward yielded rather similar conclusions. The heterogeneity across studies was very high (I² >80%). Our analyses suggested that values ≥10⁷ gc/ml may be considered reliable indicators of clinically significant bacterial infection. Conversely, 10⁴ gc/ml values likely reflect colonization. Intermediate values (10⁵-10⁶ gc/ml) pose a greater interpretative challenge. IMPORTANCE: The FA-PP assay has emerged as an ancillary tool for diagnosing lower respiratory tract infections and adjusting empirical antimicrobial therapies; consequently, it is being increasingly requested by clinicians. The current study fills a critical gap in the interpretation of quantitative data returned by the FA-PP for nosocomial bacterial targets. Assessment of the clinical relevance of FA-PP binned gc/ml values seems mandatory for clinical and therapeutic decision-making processes in patients with severe community-acquired or nosocomial pneumonia. Our analyses showed that values ≥10⁷ gc/ml are consistently associated with a high probability of culture positivity, regardless of the respiratory sample type and the bacterial target considered. In contrast, values of 10⁴ gc/ml likely reflect colonization. Our study emphasizes the need for well-designed and homogeneous studies to gauge the clinical relevance of intermediate FA-PP binned values (10⁵ and 10⁶ gc/ml).