[Mite-induced interleukin-5 and interleukin-4 expressions in peripheral blood mononuclear cells from asthmatic children with respiratory syncytial virus infection].
OBJECTIVE
To investigate the effects of respiratory syncytial virus(RSV) infection on mite-induced interleukin-5 and interleukin-4 expressions in cultures of PBMC from asthmatic children and their correlation with asthmatic symptoms.


METHODS
IL-5 and IL-4 expressions in mite (D. Pteronyssinus)-stimulated PBMC were assessed ex vivo by ELISA and reverse transcription-polymerase chain reaction (RT-PCR) in 16 allergic asthmatic children with RSV infection(A) and 14 patients without RSV infection(B), as well as 10 normal controls(C) (5.1 +/- 2.4 yrs). Meanwhile their correlation with serum ECP or current wheezing was analysed in patients after RSV infection.


RESULTS
(1) Stimulation of PBMC with mite antigens induced significantly higher IL-4 (34 +/- 24) ng/L vs (8 +/- 5) ng/L, (P < 0.01) and IL-5 (26 +/- 15) ng/L vs (6 +/- 5) ng/L release in allergic patients(B) as compared with healthy controls(C). The release was in a mite dose-dependent manner. Meanwhile, IL-5 level in group A (A) was the highest (73 +/- 47) ng/L, P < 0.05 compared with (B)). Similar results were obtained with IL-5 mRNA expressions. (2) Serum ECP level was significantly higher in group A (73 +/- 47) micrograms/L than in group C (18 +/- 12) micrograms/L, P < 0.01. There was a significant correlation between IL-5 release and ECP levels (r = 0.49, P < 0.05). (3) Mite-induced IL-5 release in PBMC was significantly increased in the group with wheezing symptom (71 +/- 40) ng/L compared with the asymptomatic group (34 +/- 29) ng/L, (P < 0.05).


CONCLUSIONS
Our findings indicated that during RSV infection, mite-induced IL-5 expression in PBMC of asthmatic children was up-regulated, which may enhance activation of eosinophils and precipitate or exacerbate asthma symptoms.
Huang
H
H
Guangzhou Institute of Respiratory Disease, Guangzhou 510120.
Chang
R
R
Ran
P
P
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000276:immunology; D001249:Asthma / Q000150:complications / Q000276:immunology*; D001798:Blood Proteins / Q000032:analysis; D016022:Case-Control Studies; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D047091:Eosinophil Granule Proteins; D005786:Gene Expression Regulation; D006801:Humans; D015847:Interleukin-4 / Q000096:biosynthesis / Q000235:genetics*; D015848:Interleukin-5 / Q000096:biosynthesis / Q000235:genetics*; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008925:Mites / Q000276:immunology*; D018357:Respiratory Syncytial Virus Infections / Q000150:complications / Q000276:immunology*; D018113:Respiratory Syncytial Virus, Human / Q000276:immunology*; D012260:Ribonucleases
D000914:Antibodies, Viral; D000956:Antigens, Viral; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D015848:Interleukin-5; D015847:Interleukin-4; D012260:Ribonucleases