A Ac cu ut te e e ex xa ac ce er rb ba at ti io on ns s o of f a as st th hm ma a i in n a ad du ul lt ts s: : r ro ol le e o of f C Ch hl la am my yd di ia a P Pn ne eu um mo on ni ia ae e i in nf fe ec ct ti io on n L. Allegra*, F. Blasi*, S. Centanni*, R. Cosentini**, F. Denti*, R. Raccanelli*, P. Tarsia*, V. Valenti* Seventy four adult out-patients with a diagnosis of acute exacerbation of asthma were studied. Acute and convalescent (≥3 weeks) serological determination of antibodies to cytomegalovirus, respiratory syncytial virus, adenovirus, influenza A and B, parainfluenza 1 and 3, Mycoplasma pneumoniae and Legionella pneumophila were performed by means of immunofluorescence tests. C. pneumoniae specific antibodies were detected by two microimmunofluorescence tests using a specific antigen (TW-183) and a kit with three chlamydial antigens. Pharyngeal swab specimens were also obtained for C. pneumoniae identification. Samples for bacterial culture were obtained in patients with productive cough (15 out of 74 patients).Fifteen patients (20%) presented seroconversion to at least one of the studied pathogens. Seven were found to be infected by virus, six by C. pneumoniae alone, and one by M. pneumoniae. One more patient showed seroconversion to C. pneumoniae and cytomegalovirus. In one out of 15 patients with productive cough, sputum culture yielded H. influenzae 10 5 colony forming units (cfu)·ml -1 .In conclusion, viruses were involved in about 9% of asthma attacks, while acute infection with intracellular bacteria was detected in 11% of cases. Notably, most of the latter (7 out of 8 cases) were due to C. pneumoniae infection. Further studies are needed in order to elucidate whether C. pneumoniae plays a role only as precipitant of asthma symptoms or is actually one of the causes of asthma.

Recent reports suggest an association between Chlamydia pneumoniae and Helicobacter pylori bacteria and atherosclerosis. We studied 51 patients (mean age, 68.3 years) who underwent abdominal aortic aneurysm surgery. For each patient we performed a microimmunofluorescence test for immunoglobulin G (IgG), IgA, and IgM antibodies to C. pneumoniae specific antigen (TW-183). Anti-H. pylori antibodies were determined by means of an EIA-G test. Each aortic aneurysm surgical specimen was sampled into multiple sections of 0.3 cm 2 each and frozen at ؊20؇C. Two samples of each aneurysm were used for a nested PCR with two sets of C. pneumoniae and two sets of H. pylori specific primers. Specimens were treated with a solution containing 20 mM Tris-HCl, Tween 20-Nonidet P-40 (0.5% [vol/vol] each), and 100 g of proteinase K per ml and incubated at 60؇C for 1 h and at 98؇C for 10 min. DNA was extracted twice with phenol-chloroform-isoamylic alcohol and precipitated with sodium acetate-ethanol by standard methods. Forty-one patients were seropositive for C. pneumoniae with past-infection patterns in 32 patients (16 < IgG < 512; 32 < IgA < 256) and high antibody titers in 9 patients (IgG > 512). In 26 of 51 patients, C. pneumoniae DNA was detected in aortic aneurysm plaque specimens. Of these patients, 23 had a serologic past-infection pattern, 2 had an acute reinfection pattern, and 1 was seronegative. Forty-seven of 51 patients were seropositive for H. pylori. In all cases PCR showed no evidence of H. pylori presence in plaque specimens. This study provides data on a possible C. pneumoniae involvement in the pathogenesis of aortic aneurysm and additional evidence for an association between this agent and atherosclerosis. Conversely, notwithstanding a high H. pylori seroprevalence observed, our results tend to rule out the possibility of a direct involvement of H. pylori in atherosclerosis.

The incidence of Chlamydia pneumoniae as a cause of community-acquired pneumonia was evaluated in a one-year prospective study in 108 patients with community-acquired pneumonia. The bacteriological diagnosis was based on culture of sputum or bronchial aspirate and examination of acute and convalescent phase sera for Mycoplasma pneumoniae, Legionella pneumophila and Chlamydia pneumoniae. A definitive microbiological diagnosis was obtained in 58 (54%) patients. Chlamydia pneumoniae was the causative agent in 14 patients (13%) on the basis of positive serological tests; in 10 of the 14 patients Chlamydia pneumoniae was also detected by means of an indirect immunofluorescence test using pharyngeal swab specimens. In conclusion, Chlamydia pneumoniae seems to be a common etiological agent of community-acquired pneumonia, as increasingly reported in the last six to seven years.