title: Persistence of specific IgM and low avidity specific IgG1 following primary rubella.
abstract: Persistence of specific IgM in sera following primary rubella infection was compared with the maturation of the specific IgG1 response. 206 sera, from 171 patients with primary rubella, taken 1 day to 2.5 years after onset of illness, were tested. Rubella-specific IgM was detected by M-antibody capture radioimmunoassay in 100% of sera taken 15-28 days after onset, but in only 9% taken 3-4 months after onset. However, using the diethylamine (DEA) shift value (DSV) method, low avidity specific IgG1 was detected in 91% sera taken at 3-4 months and at 5-7 months 21% of sera remained positive. Using an avidity index method, with urea in the wash buffer, none of the sera were positive for low avidity specific IgG1 beyond 3 months after onset. With DEA in the wash buffer, the number of sera positive rose to 38% at 3-4 months. Thus, the DSV method for detecting low avidity specific IgG1 is a useful additional test for confirming or refuting a diagnosis of primary rubella and is of particular value for assessing pregnant patients.
authors.affiliation: Department of Virology, Royal Preston Hospital, Lancashire, UK.
authors.forename: H I
authors.initials: HI
authors.lastname: Thomas
authors.forename: P
authors.initials: P
authors.lastname: Morgan-Capner
authors.forename: G
authors.initials: G
authors.lastname: Enders
authors.forename: S
authors.initials: S
authors.lastname: O'Shea
authors.forename: D
authors.initials: D
authors.lastname: Caldicott
authors.forename: J M
authors.initials: JM
authors.lastname: Best
mesh_terms: D000914:Antibodies, Viral / Q000097:blood*; D000915:Antibody Affinity; D000918:Antibody Specificity; D004048:Diethylamines; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis / Q000276:immunology; D011863:Radioimmunoassay / Q000379:methods; D012409:Rubella / Q000150:complications / Q000175:diagnosis* / Q000276:immunology*; D012412:Rubella virus / Q000276:immunology; D013997:Time Factors; D014773:Virology / Q000379:methods
chemical_list: D000914:Antibodies, Viral; D004048:Diethylamines; D007074:Immunoglobulin G; D007075:Immunoglobulin M; C034281:diethylamine