ردیابی مایکوپلاسما پنومونیه در مایع مغزی نخاعی کودکان: تعیین کمّی آنتی‌بادی اختصاصی CSF

Background: M. pneumoniae infection in children is usual and diagnosis of its neurologic complications for rapid treatment is very important. To compare the CSF- M. pneumoniae antibody level between febrile children with acute neurologic signs (Menigoencephalitis, Guillan Barre Syndrome (GBS), Transverse myelitis, Ataxia and so on) with unaffected ones.Methods: A cross sectional/ case control study in pediatric wards of Rasoul-e-Akram & Mofid hospitals (2007-2009) was done. The amount of Specific M. pneumoniae IgG (ELISA) antibody level determined in CSF of 55 cases and in 10 controls. Chi square values (CI 95%, p< 0.05) calculated for all categorical variables. Sensitivity specificity Positive Predictive Value (PPV) Negative Predictive Value (NPV) of CSF antibody level determined by using the Area under the ROC Curve.Results: Cases (n= 55) aged between five month to 13 years with mean age of 3.84±3.43 years. Area Under Curve (AUC) in ROC was 0.876 (%95 CI, 0.78- 0.96 p< 0.0001). Cut off level for antibody was 0.0025 with 73% sensitivity 90% specificity 100% PPV 28.8% NPV. CSF antibody level had significant difference between cases and controls [0.08± 0.26 Versus 0.001± 0.001 p: 0.02] It had poor agreement between cases and controls (Kappa= 0.27). Lowest amount seen in cases with aseptic meningitis highest amount observed in cases with GBS and cases with focal neurologic signs.Conclusion: The presence of very low amount (0.0025) of M. pneumoniae antibody in CSF of febrile children with acute neurologic signs had 70% sensitivity and 90% specificity 100% PPV but had low (28.8%) NPV. M. pneumoniae would be a rare cause in cases with aseptic meningitis. Finding the M. pneumoniae-DNAs in CSF are not so frequent (2%) but in high suspicious cases adding this test to determining the CSF antibody level might be helpful.