Fetal serum beta2-microglobulin as a marker for fetal infectious diseases.
OBJECTIVE
To evaluate whether fetal serum beta2-microglobulin could be used as a marker of fetal cytomegalovirus (CMV) or toxoplasmosis infection.


METHODS
beta2-microglobulin was retrospectively assayed in fetal serum collected from 64 patients with maternal infectious seroconversion (toxoplasmosis in 49 cases, CMV in 15). Using a beta2-microglobulin cutoff of 5 mg/L, infection and control groups were compared.


RESULTS
Fetal serum beta2-microglobulin was >5 mg/L (5.2-13.5 mg/L) in 12 of the 13 cases with proved fetal toxoplasmosis infection, indicating 90% sensitivity. In the 39 pregnancies with maternal seroconversion but no laboratory signs of fetal infection, fetal serum beta2-microglobulin was <5 mg/L, indicating 100% specificity. Fetal serum was >5 mg/L (6.3-32 mg/L) in 14 of the 15 cases with proved fetal CMV infection, indicating 93.3% sensitivity. Specificity cannot be evaluated because maternal serum is not routinely screened for CMV during pregnancy.


CONCLUSIONS
Fetal serum beta2-microglobulin is a reliable marker of fetal CMV or toxoplasmosis infection, which can be used in ambiguous situations. Because this increase is not specific, fetal serum beta2-microglobulin would potentially be raised in other fetal infections.
Dreux
Sophie
S
Biochimie-Hormonologie, Hôpital Robert Debré, AP-HP, 48 boulevard Sérurier, 75935 Paris cedex 19, France.
Rousseau
Thierry
T
Gerber
Stefan
S
Col
Jean-Yves
JY
Dommergues
Marc
M
Muller
Françoise
F
D015415:Biomarkers / Q000097:blood; D003586:Cytomegalovirus Infections / Q000097:blood / Q000175:diagnosis; D005260:Female; D005312:Fetal Blood; D006801:Humans; D007223:Infant; D011247:Pregnancy; D011256:Pregnancy Outcome; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014125:Toxoplasmosis, Congenital / Q000097:blood* / Q000175:diagnosis*; D001613:beta 2-Microglobulin / Q000097:blood*
D015415:Biomarkers; D001613:beta 2-Microglobulin