Association ofChlamydia pneumoniaeIgA antibodies with recently symptomatic asthma

Abstract

SUMMARYTo determine whether recently diagnosed adult-onset asthma is associated with serologic evidence of chronic Chlamydia pneumoniae infection, we performed a case-control study in a primary care clinic of cases with asthma (25 adults reporting first symptoms of asthma within 2 years of enrollment) and 45 concurrently enrolled sex and age (± 10 years) matched nonasthmatic controls with normal pulmonary function. C. pneumoniae-specific IgA, IgG and IgG4 antibodies, and circulating immune complexes (CIC) were measured by microimmunofluorescence testing. Results showed that frequencies of IgG titres > 16 (92%), IgG4 titres > 16 (20%) and CIC > 4 (60%) in asthma patients were not significantly different from those of controls. However, asthmatics had a significantly higher prevalence of C. pneumoniae-specific IgA titres > 10 (72 % of cases vs 44 % of controls, P < 0 05). After adjustment for the effects of age, sex and smoking, the odds ratio for an association of IgA and asthma was 3-7 (95 % confidence interval 1 2-11 5). We conclude that recently symptomatic reversible airway obstruction in adults is associated with the presence of C. pneumoniae-specific IgA antibodies, a proposed indicator of chronic respiratory C. pneumoniae infection.

Prevalence of antibody to Chlamydia pneumoniae in residents of Japan, the Solomon Islands, and Nepal.

“…Because the half-life of IgA is generally short, 16 it is used as an index of current or recent infection. 22,23 Chlamydia pneumoniae is also an important epidemic pathogen, causing recurrent infection. 24 Because the Solomon Islands are a region that is highly endemic for malaria, 25 respiratory diseases, and viral infections, 26 recurrent C. pneumonae infections might also occur there frequently.…”

The Association Between Chlamydia pneumoniae Infection and Ischemic Stroke

“…It should be noted that the IgA positivity rates in patients from the above study were higher than those of this study. The presence of IgA antibody in C. pneumoniae infection is short-term and represents acute infection, whereas IgG antibody lasts several months and indicates chronic infection (2). Therefore, in our study, the patients with thrombotic stroke were infected by C. pneumoniae and had acute infections.…”

“…Though, different classes of antibodies are produced in C. pneumoniae infection, each of which has a different clinical implication. For example, IgA antibody presence is short-term and represents acute infection, whereas, IgG antibody lasts several months and indicates chronic infection (2).…”

“…It is one of the most common agents involved in respiratory tract infections including pneumonia, bronchitis, pharyngitis, and sinusitis. Approximately, 5-10% of all cases of adult pneumonia and bronchitis are caused by C. pneumoniae (2,3). Atherosclerosis is a multifactorial disease.…”

Two Cases of Acute Respiratory Distress Syndrome with High Values of <i>Chlamydophila pneumoniae</i>-Specific Antibodies

“…Continuously high values of C. pneumoniae-specific AbIgA imply a continuous infection with C. pneumoniae (8). In case 1, the level of C. pneumoniae-specific Ab-IgA exceeded the diagnostic threshold (>3.0 ID) 30 days after admission.…”