Lih-Ju Lin1, Fu-Chieh Chang2, Hsin Chi3, Wai-Tim Jim3, Daniel Tsung-Ning Huang4, Yen-Hsin Kung4, Ching-Ying Huang5, Nan-Chang Chiu6, Lung Chang7. 1. Department of Pediatrics, MacKay Children's Hospital and MacKay Memorial Hospital, Taipei, Taiwan; Department of Pediatrics, Taiwan Adventist Hospital, Taipei, Taiwan. 2. Infection Control Center, MacKay Memorial Hospital, College of Management, Yuan Ze University, Taiwan. 3. Department of Pediatrics, MacKay Children's Hospital and MacKay Memorial Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medicine College, New Taipei, Taiwan; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan. 4. Department of Pediatrics, MacKay Children's Hospital and MacKay Memorial Hospital, Taipei, Taiwan. 5. Department of Pediatrics, MacKay Children's Hospital and MacKay Memorial Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medicine College, New Taipei, Taiwan. 6. Department of Pediatrics, MacKay Children's Hospital and MacKay Memorial Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medicine College, New Taipei, Taiwan; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan. Electronic address: ncc88@ms2.mmh.org.tw. 7. Department of Pediatrics, MacKay Children's Hospital and MacKay Memorial Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medicine College, New Taipei, Taiwan; MacKay Junior College of Medicine, Nursing and Management, Taipei, Taiwan; Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan. Electronic address: covis77@yahoo.com.tw.
Abstract
BACKGROUND: Mycoplasma pneumoniae is a common pathogen of respiratory tract infections in pediatric patients. Serological studies are traditional methods for the diagnosis. However, early diagnosis of M. pneumoniae infections remains problematic. We investigate the value of early serum immunoglobulin A (IgA), in addition to immunoglobulin G (IgG), and immunoglobulin M (IgM) levels, in children infected with M. pneumoniae. METHODS: From August 2016 to February 2017, we enrolled pediatric patients based on both clinical symptoms and chest x-ray, and confirmed by positive throat culture for M. pneumoniae. Serum titers of M. pneumoniae IgM, IgG, and IgA during the acute phase were checked. All respiratory samples were further analyzed by polymerase chain reaction (PCR). Diagnostic values of different tests were evaluated. RESULTS: Fifty-six patients fulfilled the diagnostic criteria, with a median age of 4.84 years. Most of them (89.3%) were enrolled within 7 days of disease onset. PCR was positive in 71.4% of the study population. Early IgG samples were of limited value in diagnosing M. pneumoniae infection, of which 89.3% showed a negative result. Positive rates of early serum IgA and IgM were 48.2% and 46.4%, respectively. In combination with IgA and/or IgM, the sensitivity increased to 71.4% during their early clinical course. CONCLUSIONS: In the pediatric population, combined serological tests of M. pneumoniae IgA and IgM, offer an accurate method of early diagnosis comparable to that of PCR, and can be an alternative choice for prompt detection of mycoplasma infections when PCR and culture are not available.
BACKGROUND: Mycoplasma pneumoniae is a common pathogen of respiratory tract infections in pediatric patients. Serological studies are traditional methods for the diagnosis. However, early diagnosis of M. pneumoniae infections remains problematic. We investigate the value of early serum immunoglobulin A (IgA), in addition to immunoglobulin G (IgG), and immunoglobulin M (IgM) levels, in children infected with M. pneumoniae. METHODS: From August 2016 to February 2017, we enrolled pediatric patients based on both clinical symptoms and chest x-ray, and confirmed by positive throat culture for M. pneumoniae. Serum titers of M. pneumoniae IgM, IgG, and IgA during the acute phase were checked. All respiratory samples were further analyzed by polymerase chain reaction (PCR). Diagnostic values of different tests were evaluated. RESULTS: Fifty-six patients fulfilled the diagnostic criteria, with a median age of 4.84 years. Most of them (89.3%) were enrolled within 7 days of disease onset. PCR was positive in 71.4% of the study population. Early IgG samples were of limited value in diagnosing M. pneumoniae infection, of which 89.3% showed a negative result. Positive rates of early serum IgA and IgM were 48.2% and 46.4%, respectively. In combination with IgA and/or IgM, the sensitivity increased to 71.4% during their early clinical course. CONCLUSIONS: In the pediatric population, combined serological tests of M. pneumoniaeIgA and IgM, offer an accurate method of early diagnosis comparable to that of PCR, and can be an alternative choice for prompt detection of mycoplasma infections when PCR and culture are not available.