Clinical Significance of Mycoplasma Pneumoniae Antibodies IgM Positive with High Titers / 实用儿科临床杂志

ABSTRACT

Objective To explore the clinical significance of mycoplasma pneumoniae(MP) antibody IgM positive with high titers.Methods Two hundred and sixty-seven cases of respiratory tract infections of MP with MP-IgM positive were confirmed in our hospital during Jun.2005 to Aug.2008,of which 63 cases with significantly increased titers of MP-IgM antibodies(MP-IgM≥11 280).A prospective observation and later analysis of the clinical manifestations of the 63 cases were carried out.Results 1.Among 63 cases,6 cases were diagnosed as upper respiratory tract infection,12 cases as acute bronchitis and 45 cases as pneumonia,respectively.2.The 63 cases pre-sented mainly with fever and cough,of them 59 cases had fever and 45 cases with paroxysmal cough,39 cases could be found crackles on physical examination.3.Extrapulmonary manifestations could be found in many cases,including heart complications in 21 cases,abnormal liver functions in 35 cases,gastrointestinal manifestations in 22 cases,neurological manifestations in 1 case,dermatological disorders in 7 cases and renal manifestations in 3 cases.4.Patterns of chest X-ray findings of the 63 cases with MP infections were varied,of which 45 cases showed pulmonary abnormality.Chest X-ray findings of the 45 children included 12 cases with interstitial infiltration,6 cases with lobar condensation,15 cases with patch shadows,4 cases with enlarged porta pulmonis and 8 cases with reticulonodular infiltrates.Three cases were complicated with pleural effusion and 2 children with segmental atelectasis.5.The cases were given azithromycin,10 mg/(kg?d),a daily dose for 5 days and intermitted for 4 days.All cases repeated the treatment courses for 1 to 4 times.The mean duration of fever was 6.6 days,cough could last 11.7 days and the crackles on physical examination could not be found 7.5 days later after treatment.The abnormality of chest X-ray findings dissolved in 38 cases 2-3 weeks later after treatment.Conclusions Cases of MP infections with high titers of MP-IgM positive had severe symptoms,of which more than 90% patients presenting with lower respiratory tract infections,mainly with pneumonia.Recovery of chest radiological finding was posterior to clinical improvement,so timely and regular chest X-ray examinations were essential after treatment and could avoid the false ceasing of treatment of the cases.Patients of MP infections with high titers of IgM antibodies positive have good prognosis.