Asthmatic children have increased specific anti-Mycoplasma pneumoniae IgM but not IgG or IgE-values independent of history of respiratory tract infection.

BACKGROUND: Bronchial asthma is exacerbated by Mycoplasma pneumoniae-induced upper respiratory tract infections (URTIs) in children. Specific IgM and IgG isotypes are involved in the immune response to M. pneumoniae, but little is known about the role of specific IgE antibodies against M. pneumoniae in asthma. OBJECTIVE: To investigate the role of IgM-, IgG- and IgE-specific antibody responses to M. pneumoniae in children with persistent asthma in relationship to history of URTI within the past 6 months. METHODS: Total or specific anti-M. pneumoniae IgM, IgG and IgE antibody responses were studied in stable asthmatic pediatric patients (M. pneumoniae positive and negative) without current exacerbation and nonasthmatic controls (N = 23 and 13, respectively) (UniCAP total IgE Fluoroenzymeimmunoassay, enzyme-linked immunosorbent assay). RESULTS: Values of specific IgM correlated with specific IgG (Spearman correlation, rho = 0.61, P < 0.0001) but not with specific IgE anti-M. pneumoniae antibodies (AMA) in asthmatic subjects compared with nonasthmatic controls. However, concentrations of specific IgG correlated with specific IgE AMA (rho = 0.49, P = 0.0017). Asthmatic subjects had higher levels of specific IgM AMA levels compared with nonasthmatics (median [interquartile range]: 0.57 [1.00] versus 0.21 [0.19]; Kruskal-Wallis test, P = 0.0008). In addition, IgM positivity was significantly higher in asthmatic compared with nonasthmatic subjects (39.1% versus 0.0%; Fisher's exact test, P = 0.01). These results were independent of URTI history in the past 6 months, which was not associated with higher IgM, IgG or IgE AMA levels compared with no URTI history (P = 0.25-0.64). CONCLUSIONS: Increased specific IgM anti-M. pneumoniae responses may indicate an important role for M. pneumoniae infection in asthma.

Long-term persistence of IgE anti-influenza A HIN1 virus antibodies in serum of children and adults following influenza A vaccination with subsequent H1N1 infection: a case study.

BACKGROUND AND METHODS: The role of immunoglobulin (Ig) E in immunity against influenza A H1N1 has not been studied. Total serum IgE and specific IgE and IgG anti-H1N1 virus responses were studied in children and adults (n = 2) who received influenza virus vaccination (Flumist(®) or Fluzone(®) ) in autumn 2008 and 2009, and then subsequently became infected with the H1N1 virus in spring 2009. Twelve months after infection, antibodies in their serum were compared with those in the serum of subjects who were either vaccinated but not infected (n = 4) or nonvaccinated and noninfected subjects (n = 2), using UniCAP total IgE fluoroenzyme immunoassay, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and Western blotting. Band sizes for the influenza virus (58, 56, 40, 30, 25, and 17 kDa) and H1N1 viral proteins (58, 56, 25, and 17 kDa) were determined, using sodium dodecyl sulfate polyacrylamide gel electrophoresis and Coomassie brilliant blue. RESULTS: We found that the serum of vaccinated and subsequently infected children and adults contained IgE and IgG antibodies to both H1N1 and influenza virus, with a strong IgE and IgG band intensity at 56 kDa. Interestingly, in subjects who were vaccinated but not infected, band intensity at 56 kDa was lowered by approximately two-fold. Serum of nonvaccinated and noninfected subjects had no detectable IgE or IgG antibodies to influenza virus or H1N1. CONCLUSION: This is the first description of IgE anti-influenza A H1N1 antibodies in human serum and the first demonstration of their long-term persistence. The decreased intensity of the 56 kDa band in vaccinated noninfected subjects compared with vaccinated infected subjects suggests augmented IgE and IgG antibody responses to influenza A H1N1.

Long term persistence of IgE anti-influenza virus antibodies in pediatric and adult serum post vaccination with influenza virus vaccine.

The production of IgE specific to different viruses (HIV-1, Parvovirus B19, Parainfluenza virus, Varicella Zoster Virus), and the ability of IgE anti-HIV-1 to suppress HIV-1 production in vitro, strongly suggest an important role for IgE and/or anti viral specific IgE in viral pathogenesis. Nevertheless, the presence and persistence of IgE anti-Influenza virus antibodies has not been studied. Total serum IgE and specific IgE and IgG anti-Influenza virus antibodies were studied in children (N = 3) (m/f 14-16 y/o) and adults (N = 3) (m/f, 41-49 y/o) 2-20 months after vaccination with Influenza virus (Flumist(®) or Fluzone(®)), as well as in non-vaccinated children (N = 2). (UniCAP total IgE Fluoroenzymeimmunoassay, ELISA, Immunoblot). We found that serum of vaccinated children and adults contained IgE and IgG anti-Influenza virus antibodies approaching two years post vaccination. Non-vaccinated children did not make either IgE or IgG anti-Influenza antibodies. Similar levels of IL-2, IFN-γ, IL-4, and IL-10 cytokines were detected in serum of vaccinated compared with non vaccinated subjects (p > 0.05), as well as between vaccinated adults compared with vaccinated children and non vaccinated subjects (p > 0.05). Vaccinated children and adults continue to produce IgE anti-Influenza virus antibodies long term post vaccination. The long term production of IgE anti-Influenza virus antibodies induced by vaccination may contribute to protective immunity against Influenza.