Caesarean Section, Chronic Infection Increase Asthma Risk

Apr 12, 2001, 01:00 ET from American Academy of Allergy, Asthma and Immunology

    MILWAUKEE, April 12 /PRNewswire/ -- Caesarean sections and chronic
 infection may be factors in the development of asthma according to two studies
 in the April Journal of Allergy & Clinical Immunology (JACI).  The JACI is the
 peer-reviewed, scientific journal of the American Academy of Allergy, Asthma
 and Immunology (AAAAI).
 
     Babies born via Caesarean section at risk of asthma in adulthood
     Babies born via Caesarean section are more likely to be diagnosed with
 asthma in adulthood according to European researchers.
     Baizhuang Xu, M.D., Ph.D., Imperial College School of Medicine, London,
 and colleagues from the National Public Health Institute, Kuopio, Finland and
 the University of Oulu, Finland, collected demographic data from a large
 cohort of children born in northern Finland in 1966.  In 1997, when the
 members of the group were 31 years of age, information on doctor-diagnosed
 asthma and other allergic disorders was obtained from 1,953 of the subjects by
 a self-administered questionnaire and allergy skin prick test.
     The researchers evaluated whether the mode of birth (vaginal delivery vs.
 caesarean section) had any significant impact upon the subsequent development
 of allergies and asthma in young adulthood.  The type of delivery had no
 significant impact on the development of allergies, hay fever, or allergic
 eczema in this cohort of 31-year-old Finnish subjects.  Interestingly,
 however, those young adults born by C-section were 3 times more likely to have
 developed asthma than their peers who had been delivered vaginally at birth.
     The cause of this observed association is unknown.  The authors note that
 almost all C-sections performed in Finland in the 1960's were the result of
 perinatal/obstetrical emergencies.  The researchers theorized that unknown
 factors associated with caesarean section or the consequences of caesarean
 section may explain the association observed.  They also speculated that
 fetuses that will later develop asthma may develop obstetric complications and
 increased risk of caesarean section.
     The authors also noted that the frequency of births by C-section in
 Finland may now be five-fold greater than in the 1960's, so further study on
 this interesting observation is warranted.
 
     A link between chronic asthma and chronic infection?
     New research shows a possible link between chronic bacterial respiratory
 infections and persistent asthma.  The study was conducted by Richard J.
 Martin, M.D., from the National Jewish Medical and Research Center, Denver,
 and colleagues from Northwestern University Medical School, Chicago, and the
 University of Alabama-Birmingham.
     Martin and his colleagues sought to define the association between chronic
 asthma and Mycoplasma and Chlamydia species, bacterial microorganisms
 responsible for respiratory tract infections, by performing a comparison study
 of 55 stable, chronic asthmatic patients and 11 non-asthmatic control
 subjects.  Blood specimens, nasopharyngeal swabs, bronchoalveolar lavage
 fluids and tissues obtained by lung biopsy were obtained and studied for
 evidence of infection by these two species of bacteria.
     Researchers found that 25 of the 55 asthmatic patients tested positive for
 Mycoplasma, while only one of the eleven control subjects tested positive.
 Seven of the 55 asthmatic patients tested positive for Chlamydia while none of
 the control subjects had positive results Mycoplasma, Chlamydia, or both were
 found in the airways of 31 (56.4%) asthmatic patients.
     The investigators found that asthmatic subjects with evidence of chronic
 infection also had increased numbers of mast cells (cells critical to
 asthmatic reactions) in their lung tissue when compared to those asthmatic
 patients with negative test results.
     Researchers also found that medication may possibly affect microorganisms
 in the airways.  Those asthmatics not using inhaled corticosteroids (the most
 effective medicine currently available for the treatment of chronic asthma)
 were twice as likely to have evidence of chronic infection, when compared to
 those asthmatics taking their inhaled corticosteroids on a regular basis.
     Respiratory viral infections have long been implicated as a potent trigger
 of asthmatic reactions.  These researchers have now found that a significant
 proportion of their chronic asthmatic subjects had Mycoplasma, Chlamydia or
 both present in their airways suggesting that chronic bacterial respiratory
 infections may also contribute to asthma.  This connection will almost
 certainly influence the way chronic asthma is evaluated and treated, according
 to researchers.
 
     The AAAAI is the largest professional medical specialty organization in
 the United States representing allergists, asthma specialists, clinical
 immunologists, allied health professionals and others with a special interest
 in the research and treatment of allergic disease.  Allergy/immunology
 specialists are pediatric or internal medicine physicians who have elected an
 additional two years of training to become specialized in the treatment of
 asthma, allergy and immunologic disease.  Established in 1943, the Academy has
 more than 6,000 members in the United States, Canada and 60 other countries.
 The Academy serves as an advocate to the public by providing educational
 information through its Web site at http://www.aaaai.org
 
 

SOURCE American Academy of Allergy, Asthma and Immunology
    MILWAUKEE, April 12 /PRNewswire/ -- Caesarean sections and chronic
 infection may be factors in the development of asthma according to two studies
 in the April Journal of Allergy & Clinical Immunology (JACI).  The JACI is the
 peer-reviewed, scientific journal of the American Academy of Allergy, Asthma
 and Immunology (AAAAI).
 
     Babies born via Caesarean section at risk of asthma in adulthood
     Babies born via Caesarean section are more likely to be diagnosed with
 asthma in adulthood according to European researchers.
     Baizhuang Xu, M.D., Ph.D., Imperial College School of Medicine, London,
 and colleagues from the National Public Health Institute, Kuopio, Finland and
 the University of Oulu, Finland, collected demographic data from a large
 cohort of children born in northern Finland in 1966.  In 1997, when the
 members of the group were 31 years of age, information on doctor-diagnosed
 asthma and other allergic disorders was obtained from 1,953 of the subjects by
 a self-administered questionnaire and allergy skin prick test.
     The researchers evaluated whether the mode of birth (vaginal delivery vs.
 caesarean section) had any significant impact upon the subsequent development
 of allergies and asthma in young adulthood.  The type of delivery had no
 significant impact on the development of allergies, hay fever, or allergic
 eczema in this cohort of 31-year-old Finnish subjects.  Interestingly,
 however, those young adults born by C-section were 3 times more likely to have
 developed asthma than their peers who had been delivered vaginally at birth.
     The cause of this observed association is unknown.  The authors note that
 almost all C-sections performed in Finland in the 1960's were the result of
 perinatal/obstetrical emergencies.  The researchers theorized that unknown
 factors associated with caesarean section or the consequences of caesarean
 section may explain the association observed.  They also speculated that
 fetuses that will later develop asthma may develop obstetric complications and
 increased risk of caesarean section.
     The authors also noted that the frequency of births by C-section in
 Finland may now be five-fold greater than in the 1960's, so further study on
 this interesting observation is warranted.
 
     A link between chronic asthma and chronic infection?
     New research shows a possible link between chronic bacterial respiratory
 infections and persistent asthma.  The study was conducted by Richard J.
 Martin, M.D., from the National Jewish Medical and Research Center, Denver,
 and colleagues from Northwestern University Medical School, Chicago, and the
 University of Alabama-Birmingham.
     Martin and his colleagues sought to define the association between chronic
 asthma and Mycoplasma and Chlamydia species, bacterial microorganisms
 responsible for respiratory tract infections, by performing a comparison study
 of 55 stable, chronic asthmatic patients and 11 non-asthmatic control
 subjects.  Blood specimens, nasopharyngeal swabs, bronchoalveolar lavage
 fluids and tissues obtained by lung biopsy were obtained and studied for
 evidence of infection by these two species of bacteria.
     Researchers found that 25 of the 55 asthmatic patients tested positive for
 Mycoplasma, while only one of the eleven control subjects tested positive.
 Seven of the 55 asthmatic patients tested positive for Chlamydia while none of
 the control subjects had positive results Mycoplasma, Chlamydia, or both were
 found in the airways of 31 (56.4%) asthmatic patients.
     The investigators found that asthmatic subjects with evidence of chronic
 infection also had increased numbers of mast cells (cells critical to
 asthmatic reactions) in their lung tissue when compared to those asthmatic
 patients with negative test results.
     Researchers also found that medication may possibly affect microorganisms
 in the airways.  Those asthmatics not using inhaled corticosteroids (the most
 effective medicine currently available for the treatment of chronic asthma)
 were twice as likely to have evidence of chronic infection, when compared to
 those asthmatics taking their inhaled corticosteroids on a regular basis.
     Respiratory viral infections have long been implicated as a potent trigger
 of asthmatic reactions.  These researchers have now found that a significant
 proportion of their chronic asthmatic subjects had Mycoplasma, Chlamydia or
 both present in their airways suggesting that chronic bacterial respiratory
 infections may also contribute to asthma.  This connection will almost
 certainly influence the way chronic asthma is evaluated and treated, according
 to researchers.
 
     The AAAAI is the largest professional medical specialty organization in
 the United States representing allergists, asthma specialists, clinical
 immunologists, allied health professionals and others with a special interest
 in the research and treatment of allergic disease.  Allergy/immunology
 specialists are pediatric or internal medicine physicians who have elected an
 additional two years of training to become specialized in the treatment of
 asthma, allergy and immunologic disease.  Established in 1943, the Academy has
 more than 6,000 members in the United States, Canada and 60 other countries.
 The Academy serves as an advocate to the public by providing educational
 information through its Web site at http://www.aaaai.org
 
 SOURCE  American Academy of Allergy, Asthma and Immunology