Table 2. Positive results of different laboratory tests in 164 children of different ages infected with MP infection confirmed by BALF PCR.
| Parameters | ≤1-year-old (n=23) | 1–3 years old (n=23) | 3–5 years old (n=52) | >5 years old (n=66) | P value |
|---|---|---|---|---|---|
| IgM [n (%)] | 5 (21.74) | 17 (73.91)a | 36 (69.23)a | 47 (71.21)a | <0.001 |
| Paired IgG [n (%)] | 9 (39.13) | 12 (52.17) | 30 (57.69) | 38 (57.58) | 0.440 |
| NPA PCR [n (%)] | 7 (30.43) | 15 (65.22) | 30 (57.69) | 48 (72.72)a | 0.004 |
| Combinated IgM and NPA PCR test [n (%)] | 9 (39.13) | 18 (78.26) | 41 (78.85)a | 56 (84.85)a,e | <0.001 |
| P value | 0.537 | 0.245 | 0.064 | 0.007 | – |
Positive results of the same diagnostic test indifferent age groups were compared. a, P<0.05 compared with patients ≤1-year-old. Positive results of different diagnostic tests in the same age group were compared. e, P<0.05 compared with the diagnostic teste of paired IgG. MP, Mycoplasma pneumoniae; BALF, bronchoalveolar lavage fluid; PCR, polymerase chain reaction; IgM, immunoglobulin M; IgG, immunoglobulin G; NPA, nasopharyngeal aspirate.