| Abstract | BACKGROUND: Human cytomegalovirus (HCMV) is the most common cause of viral intrauterine infection. Fetal damage is mostly linked to maternal primary infection. It is therefore important to differentiate primary from non-primary infection in pregnant females. IgM tests often used for this purpose are not reliable enough. OBJECTIVE: To evaluate an HCMV-IgG urea-elution assay for its ability to distinguish primary from non-primary infection. In this assay, soaking the antigen-antibody complex with an urea containing solution frees antibodies with low avidity but has no influence on those with high avidity. An avidity index (AI) was calculated: AI = (OD with urea/OD without urea) x 100. STUDY DESIGN: HCMV-IgG avidity was measured on a single serum of 79 patients with past infection (pregnant women, graft recipients and blood donors) and of 63 patients (78 sera) with documented seroconversion (pregnant women and graft recipients). Sixty-one pregnant women positive or equivocal for HCMV-IgM but without a documented seroconversion were included in this study. RESULTS: Most (72/79) of the patients with past infection had an AI > 65% and all but one had an AI > 50%. In pregnant women, in the case of a primary infection within the past 3 months, AI are usually (51/53) < 50% and never > 65%. Among the IgM positive pregnant women who lack a seroconversion history, 38 had AI > 65% suggestive of an infection that had occurred at least 3 months earlier, 11 had an AI in a grey area between 50 and 65% and 12 had an AI < 50%, suggestive of a recent primary infection. CONCLUSIONS: In pregnant women, measurement of the IgG avidity may help to date a HCMV infection, an AI > 65% highly suggests a past infection while an AI < 50% corresponds to a recent primary infection. |
| Authors | M Bodéus, S Feyder, P Goubau
(Affiliation: Department of Microbiology, Catholic University of Louvain, UCL 3055, Brussels, Belgium.)
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| Journal | Clinical and diagnostic virology
(Clin Diagn Virol)
Vol. 9
Issue 1
Pg. 9-16
(Jan 1998)
ISSN: 0928-0197 NETHERLANDS |
| PMID | 9562853
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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| Chemical References |
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| Topics |
- Antibody Affinity
(immunology)
- Cytomegalovirus Infections
(immunology, virology)
- Female
- Humans
- Immunoenzyme Techniques
- Immunoglobulin G
(analysis, immunology)
- Pregnancy
- Pregnancy Complications, Infectious
(immunology, virology)
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