Improved Diagnostics Help to Identify Clinical Features and Biomarkers That Predict Mycoplasma pneumoniae Community-acquired Pneumonia in Children

Meyer Sauteur, Patrick M; Krautter, Selina; Ambroggio, Lilliam; Seiler, Michelle; Paioni, Paolo; Relly, Christa; Capaul, Riccarda; Kellenberger, Christian; Haas, Thorsten; Gysin, Claudine; Bachmann, Lucas M; van Rossum, Annemarie M C; Berger, Christoph

During the 12-month study period, 152 CAP patients were enrolled and Mp DNA was detected by PCR in 44 (29%) participants. Of the enrolled population, 63 (41%) CAP patients met the criteria of having fresh PBMCs available to undergo diagnostic testing with the Mp IgM ASC ELISpot assay and were included in this study. Of these, 29 (46%) were Mp-positive, determined by detection of Mp IgM ASCs. As detailed elsewhere [9] , all 29 Mp IgM ASC-positive patients were also Mp PCR positive and IgM positive. However, Mp PCR was also positive in 3 (5%) patients who were Mp IgM ASC and IgM negative, and Mp IgM was found in another 3 (5%) patients who were Mp IgM ASC and PCR negative. Chest radiographs were performed in 60 of 63 (95%) included CAP patients, whereof 59 (98%) met the criteria for radiographic pneumonia. Fever was detected in the URT of 9 siblings (64%), 7 mothers (35%), and 1 father (8%). Most of them reported having RTI symptoms (59%), but 6 siblings and 1 mother were asymptomatic carriers. The duration of RTI symptoms and fever prior to CAP diagnosis was longer in Mp-positive (median, 9.0 [IQR, 6.0-10.0] days) than Mp-negative patients (4.0 [IQR, 3.0-7.0] days; P < .01). No other symptoms and signs were statistically different between groups. Mp-positive patients were no different than Mp-negative patients to have consolidation, interstitial infiltrates, or pleural effusion. Extrapulmonary manifestations were only observed in Mp-positive children with CAP (31% vs 0%; P < .01) and included dermatological and neurological disorders (Table 1) . After inclusion, 9 (31%) of Mp-positive patients were not treated with an antibiotic in vitro active against Mp.