Rapid, Accurate and Novel Diagnostic Technique for Respiratory Pathogen: the Clinical Application of Loop-Mediated Isothermal Amplification Assay in Elderly Patients with Pneumonia, a Multicenter Prospective Observational Study

Background: Chips for Complicated Infection Detection (CCID) is based on Loop-mediated Isothermal Amplification (LAMP) and has technical advantages in pathogenic diagnosis. We transformed it into clinical application and evaluated its diagnostic value for pneumonia in the elderly.Methods: 81 elderly patients diagnosed with pneumonia were prospectively enrolled in 10 hospitals including Peking University First Hospital from January 1 st to July 23 rd 2021, from which 57 sputum/ airway secretion and 35 bronchoalveolar lavage fluids (BALF) were collected to be detected by the CCID and conventional microbiological tests (CMTs).Results: We formed a whole process including sample collection, delivering, monitoring, management and feedback by multi-disciplinary team, whose carrier was Sample Management Information System. The CCID demonstrated the reaction time of 50 minutes, and the lower detection limit of 500 copies/reaction. For the pneumonia in the elderly, the percentage of CCID positive samples was significantly higher than that detected by the CMTs, especially for Klebsiella pneumoniae (odds ratio [OR], 9·0 [95% confidence interval {CI}, 1·1–70·5]; P <0·05), Enterococcus faecalis (OR, ∞ ; P <0·01), Stenotrophomonas maltophilia (OR, ∞ ; P <0·01), fungi (OR, 26·0 [95% CI , 3.6–190.0]; P < .01), and viruses (CCID only; P < 0·01). Interestingly, the positivity rate of CCID was higher to that of CMTs in cases with more than 3 days antibiotic use (91 ·9% vs 64·9%; P < 0·01). Importantly, positive impact was defined as confirming the diagnosis, detecting pathogen faster, continuing empirical treatment, and treatment adjusted. In terms of diagnosis, 59·8% had positive impact. In terms of treatment, continuing empirical treatment and treatment adjusted, respectively accounted for 55·4% and 4·4%.Interpretation: CCID has advantages of detecting pathogens in the elderly pneumonia, with rapid and accurate detection efficiency. It is less affected by prior antibiotic exposure and has good potential value of contributing to better patient care.Funding: National Key R&D Program of China (2020YFC2005401), Xicheng financial, scientific and technological project (XCSTS-SD2021-02), Project funded by Baidu Fund of Peking University (2020BD045).Declaration of Interest: SW, LW, MS, JL, CS, YW, LH, FT, LL, XM, WT, CL, JL, BS, BD, YO, LL, and XL declare that they have no conflict of interest. YL and ZZ is affiliated with Boao Biological Group Co., Ltd.Ethical Approval: The local ethics committee approved the protocol for this study (Number 2021-132). Written informed consent was obtained from all participants.