[Seroprevalence of antibody against human metapneumovirus in Beijing].
OBJECTIVE
To understand the seroprevalence of antibody against the newly identified human metapneumovirus (hMPV) in Beijing.


METHODS
The antigenic specificity of hMPV N protein cloned into vector pET30a and then expressed in E coli was verified by using SDS-PAGE and Western blotting in 116 serum specimens. The plasmid pET30a without insert was used as control. Totally 710 serum specimens collected from non-respiratory infection patients visited the Outpatient Departments of Children's Hospital affiliated to Capital Institute of Pediatrics and Xuanwu Hospital, Beijing from April 1996 to March 1997 were tested for specific IgG antibody against hMPV N protein.


RESULTS
The bands with expected molecular weight showed only on the membranes transferred by the expressed hMPV N protein and incubated with rabbit hyperimmune serum against hMPV N protein polypeptides as well as the collected human sera, indicating the specificity of the expressed hMPV N protein. Out of 710 specimens tested, 17.2% (122/710) were positive for antibody to N protein. Antibody positive rate was the lowest in 2 to 6 months old infants (3.1%); the rate declined from 13.2% in newborns to 6.1% in 1 to 2 months old infants, then to 3.1% in the 2 to 6 months group, and sustained at about 3.0% from 6 months group to 30 years of age, then increased to 28.1% in 30 to 39-year-old adults, 32.3% in 40 to 49-year-old adults and to 38.5% in the group over age of 50 years.


CONCLUSIONS
The expressed hMPV N protein is reliable when it was used as antigen for testing specific IgG antibody against hMPV in human sera. The high seroprevalence of antibody against hMPV N protein and early age antibody acquisition suggest that hMPV has been circulating in Beijing and the importance of the virus as pathogen should be further analyzed.
Zhao
Lin-qing
LQ
Laboratory of Virology, Beijing Municipal Laboratory of Infection and Immunity, Capital Institute of Pediatrics, Beijing, 100020, China.
Cao
Shou-chun
SC
Zhu
Ru-nan
RN
Li
Guo-hua
GH
Deng
Jie
J
Wang
Fang
F
Jia
Li-ping
LP
Qian
Yuan
Y
D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D000918:Antibody Specificity; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D029121:Metapneumovirus / Q000276:immunology*; D008875:Middle Aged; D018184:Paramyxoviridae Infections / Q000453:epidemiology* / Q000276:immunology; D016036:Seroepidemiologic Studies; D014764:Viral Proteins / Q000276:immunology; D055815:Young Adult
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D014764:Viral Proteins