A Novel Diagnostic Scoring System to Differentiate between Legionella pneumophila Pneumonia and Streptococcus pneumoniae Pneumonia.
Intern Med. 2018 Mar 30;:
Authors: Saraya T, Nunokawa H, Ohkuma K, Watanabe T, Sada M, Inoue M, Honda K, Oda M, Ogawa Y, Tamura M, Yokoyama T, Kurai D, Kimura H, Ishii H, Goto H, Takizawa H
Objective We investigated a novel diagnostic scoring system to differentiate Legionella pneumophila pneumonia from Streptococcus pneumoniae pneumonia. Methods We retrospectively reviewed the clinical data of 62 patients with L. pneumophila pneumonia (L-group) and 70 patients with S. pneumoniae pneumonia (S-group). Results The serum sodium (Na) levels tended to be lower according to the severity (A-DROP) score in the L-group. On a multivariate analysis, we found that four factors were independent predictive markers for inclusion in the L-group: relative bradycardia (hazard ratio [HR] 5.177, 95% confidence interval [CI]: 1.072-24.993, p=0.041), lactate dehydrogenase (LDH) levels ≥292 IU/L (HR 6.804, 95% CI: 1.629-28.416, p=0.009), C-reactive protein (CRP) levels ≥21 mg/dL (HR 28.073, 95% CI: 5.654-139.462, p<0.001), and Na levels ≤137 meq/L (HR 5.828, 95% CI: 1.411-24.065, p=0.015). Furthermore, a total score (ranging from 0 to 4, the sum of the points for each factor [0 or 1]) ≥3 points indicated a higher probability of inclusion in the L-group than in the S-group. The diagnostic accuracy of a total score of 3 had a sensitivity of 36.3%, specificity of 100%, and area under the curve of 0.682 (95% CI: 0.558-0.806, p=0.004), and that of a total score of 4 had a sensitivity 27.4%, specificity of 98.2%, and AUC of 0.627 (95% CI: 0.501-0.754, p=0.045). The diagnostic accuracy had low sensitivity but high specificity. Conclusions We found four markers that might be useful for differentiating L-group from S-group and created a novel diagnostic scoring system.
PMID: 29607950 [PubMed - as supplied by publisher]