Chlamydial antibodies in an elderly Finnish population.

The characteristic feature of Chlamydia is its tendency to cause chronic infections. It has been hypothesized that prior exposure to C. pneumoniae may lead to chronic infection and the development of associated chronic cardiopulmonary disease. Few studies have so far addressed the occurrence of chlamydial antibodies in an elderly, unselected population. This information is important for the development of possible treatment strategies. Chlamydial antibodies were analysed from 1179 serum samples obtained from 481 men and 698 women, aged 64 y and over, who participated in an epidemiological survey carried out in a Finnish rural district. Specific IgG and IgA antibodies were measured by the microimmunofluorescence (micro-IF) test. The criterion for seropositivity was defined as a titre of > or =32 for both IgG and IgA, independently of each other. C. pneumoniae IgG antibodies occurred in 91% of the men and 75% of the women. The respective figures for C. pneumoniae IgA antibodies were 57% and 28%. The geometric mean titres (GMT) rose with increasing age and were higher in men than in women. The prevalences of C. trachomatis IgG antibodies were 13% in men and 18% in women, and for IgA antibodies, 2% and 1%, respectively. C. psittaci antibodies were rare. Only 3% of the men and women were IgG seropositive, whereas the respective figures for IgA seropositivity were 0.4% and 0.1%. C. pneumoniae antibodies indicative of recurrent or chronic infection were common in the elderly. The geometric mean titres correlated positively with age and were higher in men than in women. Other chlamydial antibodies occurred in low titres.

Asthma, atopy and Chlamydia pneumoniae antibodies in adults.

BACKGROUND: Factors involved in the development of inflammation and asthma in nonatopic subjects have remained largely obscure, although there is some evidence to suggest that certain infections may play a role. OBJECTIVE: We investigated the association between serological evidence of Chlamydia pneumoniae infection and asthma in adults, and the possible modifying effect of the patients' atopic status on this association. METHODS: Four hundred and thirty consecutive patients who attended the hospital between 1992 and 1993 with symptoms suggestive of asthma, rhinitis or allergy were enrolled. Diagnostic procedures including lung function measurements and skin-prick tests were performed in all patients. The patients with established asthma (n = 332) were divided into those with recent asthma (n = 224, onset 1985 onward) and longstanding asthma (n = 108, onset before 1985). The controls (n = 98) comprised all subjects who did not meet the criteria of asthma. Serum immunoglobulin (Ig)G, IgA and IgM antibodies to C. pneumoniae were measured by the microimmunofluorescence test. RESULTS: In women, the prevalences of elevated IgG (a titre of >/= 128) and IgA (>/= 32) antibody levels and the age-adjusted geometric mean titres (GMT) of IgG and IgA antibodies were invariably highest among subjects with nonatopic longstanding asthma. Elevated IgG titres in women occurred in 11% of controls, in 28% of nonatopic recent onset asthmatics, and in 43% of asthmatics with nonatopic longstanding disease; for men the respective figures were 33, 50 and 64%. Logistic regression analysis controlling for age, sex and smoking showed that asthma was significantly associated with elevated IgG antibody levels to C. pneumoniae (odds ratio 3.3, 1.6-6.8 for longstanding asthma, 2.3, 1. 2-4.4 for recent asthma, and among women only 4.2, 1.6-10.9 for longstanding asthma, and 3.0, 1.3-7.2 for recent asthma). When the atopics and nonatopics were analysed separately, an even stronger relationship in the nonatopics was obtained for longstanding asthma (6.0,2.1-17.1). In contrast, the relationship between atopic asthma, either recent or longstanding, and elevated IgG titres was not significant, indicating that asthma per se does not predispose to C. pneumoniae infection. CONCLUSIONS: Asthma was significantly associated with elevated IgG antibody levels to C. pneumoniae, and this association was strongest for nonatopic longstanding asthma.

Chlamydia pneumoniae antibodies in chronic obstructive pulmonary disease.

BACKGROUND: The significance of persistent or recurrent respiratory infections in adult life for the development of chronic obstructive pulmonary disease (COPD) is still to a large extent unknown. A few clinical and experimental animal studies suggest that peripheral airways diseases may be due to the cumulative effects of recurrent respiratory infections over an extended period. METHODS: C. pneumoniae-specific IgG and IgA antibody levels were determined in two elderly groups of male patients with COPD and in control subjects without the disease. The first group (N = 36) consisted of patients who were hospitalized due to an acute exacerbation of COPD. The second group of patients (N = 54) and the controls (N = 321) were participants in a community survey on respiratory diseases in the elderly. The criteria for seropositivity were defined as an IgG titre of >=16. RESULTS: 89% of the hospitalized patients (group I) and 66% of the non-hospitalized patients (Group II) were IgA seropositive as compared to 55% of the controls. Derived from the logistic regression analysis, the odds ratio (OR) WAS 7.4 (95% CI : 2.1-25.7) between group I and the controls and 1.5 (0.7-2.9) between group II and controls. Furthermore, the difference in the age-adjusted geometric mean titres (GMT) of lgA antibodies between the group I and the controls was significant (53.0 for the patients versus 19.1 for the controls). On the contrary, no significant differences between the patients and the controls were found either in the proportion of IgG-seropositive or in the GMT of IgG antibodies. Two of the 29 patients with an exacerbation of COPD, for whom paired sera were available, showed an antibody response suggesting a current acute or reactivated chlamydial infection. CONCLUSIONS: The results showed that C. pneumoniae lgA antibodies are found more frequently and in higher concentrations in COPD patients than in disease-free controls. The finding may indicate a chronic C. pneumoniae infection in these patients. The association persisted after controlling for the potential confounding effect of smoking.