A Pilot Study of Quantitative Loop-mediated Isothermal Amplification-guided Target Therapies for Hospital-acquired Pneumonia.

BACKGROUND: It is important to achieve the definitive pathogen identification in hospital-acquired pneumonia (HAP), but the traditional culture results always delay the target antibiotic therapy. We assessed the method called quantitative loop-mediated isothermal amplification (qLAMP) as a new implement for steering of the antibiotic decision-making in HAP. METHODS: Totally, 76 respiratory tract aspiration samples were prospectively collected from 60 HAP patients. DNA was isolated from these samples. Specific DNA fragments for identifying 11 pneumonia-related bacteria were amplified by qLAMP assay. Culture results of these patients were compared with the qLAMP results. Clinical data and treatment strategies were analyzed to evaluate the effects of qLAMP results on clinical data. McNemar test and Fisher's exact test were used for statistical analysis. RESULTS: The detection of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Stenotrophomonas maltophilia, Streptococcus pneumonia, and Acinetobacter baumannii by qLAMP was consistent with sputum culture (P > 0.05). The qLAMP results of 4 samples for Haemophilus influenzae, Legionella pneumophila, or Mycoplasma pneumonia (MP) were inconsistent with culture results; however, clinical data revealed that the qLAMP results were all reliable except 1 MP positive sample due to the lack of specific species identified in the final diagnosis. The improvement of clinical condition was more significant (P < 0.001) in patients with pathogen target-driven therapy based on qLAMP results than those with empirical therapy. CONCLUSION: qLAMP is a more promising method for detection of pathogens in an early, rapid, sensitive, and specific manner than culture.

[The characteristics and clinical manifestation of subjects with non-specific pattern of pulmonary function tests].

OBJECTIVE: To analyze the characteristics of pulmonary function and the clinical significance of non-specific pattern (NSP). METHODS: A total of 1933 pulmonary function tests of adult patients were analyzed, and those with NSP were selected. The pulmonary function test results, clinical diagnosis and radiological manifestations were analyzed. Normal distribution data were compared by t test, while non-normal distribution data were compared by Mann-Whitney U test, and χ(2) test was used to compare ratios. RESULTS: There were 61 patients in the NSP group and 1017 in the control group. The BMI of the 2 groups was (24.5 ± 4.6) and (24.5 ± 3.8) kg/m(2), respectively, being not significantly different (t = 0.008, P > 0.05). The age was 64 (49-74) years and 56 (42-70) years, and the smoking index was 0.4 (0-20) and 0 (0-10), respectively, showing no significant differences (Z values were -2.209 and -2.571, respectively, all P < 0.05). In the NSP group, FEV1 was 69% (66%-73%) predicted, FVC 75% (70%-77%) predicted, FEV1/FVC 75% (73%-78%), RV 118% (105%-145%) predicted, and TLC 86% (82%- 93%) predicted, which were significantly different as compared to those of the control group [95% (87%-104%), 98% (90%-106%), 79% (76%-84%), 101% (88%-114%) and 94% (88%-102%), respectively],(Z values are -13.059--5.185, all P < 0.05). RV/TLC was (52 ± 11)% in the NSP group and (39 ± 9)% in the control group, the difference being significant (t = -10.351, P < 0.05). The decreased TLC indicated restricted ventilation, while the increased RV and RV/TLC indicated air trapping. The clinical diagnosis of NSP included obstructive and restrictive diseases, some of which showed severe radiological abnormalities, but there were 31 patients without pulmonary lesions. CONCLUSIONS: Age and smoking, but not obesity, may play a role in NSP.NSP has characteristics of obstructive and restrictive ventilation defects, but does not associate with particular diseases, thus having limited clinical significance.