Clinical Study Of The Relationship Between Atypical Pathogens, Interleukin-1 Family Gene Polymorphism And Community-acquired Atypical Pneumonia

Objectives:1.To discuss the infection of atypical pathogens (Mycoplasma pneumoniae, Chlamydia pneumoniae) of atypical pneumonia in adult community-acquired pneumonia in Tianjin, to guide clinical diagnosis and treatment of CAP.2. To investigate the association between interleukin-1 receptor antagonist (IL-1 Ra) gene VNTR polymorphism and Interleukin-1βgene polymorphic site Taq I with exon 5 and CAP in population of Tianjin.Methods:We collected 120 cases of adult CAP patients referred to the Second Hospital of Tianjin Medical University and Tianjin First Central Hospital from April 2008 to March 2009. All are in line with the diagnostic criteria of atypical pneumonia《community-acquired pneumonia treatment guidelines》recommended by the Japanese Respiratory Society in 2006:①Age<60;②no or only mild disease;③Intractable cough;④Chest physical examination was normal;⑤No sputum or rapid diagnostic tests found no pathogens;⑥WBC<10×109/L. Passive agglutination was used to detect Mycoplasma pneumoniae antibody, Polymerase chain reaction and Indirect immunofluorescence titration flat-panel technology was used to detect Chlamydia pneumoniae DNA and Chlamydia pneumoniae IgM antibody. Then we analyze of the infection of these two pathogens in CAP patients.29 cases (24.2%) infected with atypical pathogens (Chlamydia pneumoniae, Mycoplasma pneumoniae) was selected as the observation grou p,and 41 cases (34.2%) infected of other bacteria as the control group. A respectively analysis of clinical manifestation, auxiliary examination of the two groups was made. According to the progress of CAP, and the guidelines revised by America State Thoracic Society (ATS) in 2001,we defined 50 patiests as serious CAP group, The remaining 70 patiests as mild group, the polymease chain (PCR) reaction and restriction fragment length polymorphism methods (RFLP) was used to study the distribution of the VNTR polymorphism of IL-1Ra gene and polymorphic site of interleukin-1βgene with exon 5.Results:120 patients was collected, the distribution of causal agents was as follows: Mycoplasma pneumoniae 28(23.3%), Chlamydia pneumoniae 1(0.8%), Streptococcus pneumoniae 15(12.5%),Hemophilus influenza10(8.4%),Escherichia coli 5(4.2%), Moraxelle catarrhalis 5(4.2%),mixsed infection of Mycoplasma pneumoniae and Hemophilus influenza 4(3.3%), mixsed infection of Mycoplasma pneumoniae and Streptococcus pneumoniae 2(1.7%).15 patients had been treated by beta-lactam for 5-6 days before hospital admission, but the patients'body temperature didn't descend and their symptoms didn't relieved. After admission all of the patients had been treated by Azithromycin for 7～14 days, then 15 patients' body temperature descended to normal temperature.Within 7 days and their shadow of chest images disappeared after 2～4 weeks. In the control group, the patients had been treated by Levofloxacin for 7～14 days after admission. The patients' body temperature descended to normal temperature within 7 days,and their shadow of chest images disappeared after 2～4 weeks.There are 5 alleles in IL-1Ra VNTR:IL-1A1,IL-1A2,IL-1A3,IL-1A4andIL-1A5. After the effects of by Taq I,PCR amplification products of IL-1βgenerated 3 alleles:C/C; T/T; C/T. The frequency of the type A2 alleles and the A1/A2 genotype distribution in the mild group is significantly increased compared with in the serious group, for IL-1βgene, no significant difference was found in both groups on allele frequency and genotype distribution.Conclusions:Adults with atypical pneumonia In the Tianjin area, Atypical pathogens (Mycoplasma pneumoniae, Chlamydia pneumoniae) infection was only 24.1%, Streptococcus pneumoniae, Haemophilus influenzae, and mixed infections also account for a large proportion, Tip of atypical pneumonia, we should pay attention to clinical detection of pathogens in order to guide the application of antibiotics.Not occurred in the winter season,no significant effect of macrolide therapy in patients with Macrolide antibiotics, we should consider Bacterial pneumonia and mixed infections.The study of gene polymorphisms shows that IL-1 Ra A2 allele may have the potentially protective effect on the progress of CAP,and it provide a theoretical basis of using Antagonist treatment to the serius CAP patients who don't carry A2 allele.