Reduced mother-to-child transmission of HIV associated with infant but not maternal GB virus C infection.
BACKGROUND
Prolonged coinfection with GB virus C (GBV-C) has been associated with improved survival in human immunodeficiency virus (HIV)-infected adults. We investigated whether maternal or infant GBV-C infection was associated with mother-to-child transmission (MTCT) of HIV-1 infection.


METHODS
The study population included 1364 HIV-infected pregnant women enrolled in 3 studies of MTCT of HIV in Bangkok, Thailand (the studies were conducted from 1992-1994, 1996-1997, and 1999-2004, respectively). We tested plasma collected from pregnant women at delivery for GBV-C RNA, GBV-C antibody, and GBV-C viral genotype. If GBV-C RNA was detected in the maternal samples, the 4- or 6-month infant sample was tested for GBV-C RNA. The rates of MTCT of HIV among GBV-C-infected women and infants were compared with the rates among women and infants without GBV-C infection.


RESULTS
The prevalence of GBV-C RNA in maternal samples was 19%. Of 245 women who were GBV-C RNA positive, 101 (41%) transmitted GBV-C to their infants. Of 101 infants who were GBV-C RNA positive, 2 (2%) were infected with HIV, compared with 162 (13%) of 1232 infants who were GBV-C RNA negative (odds ratio [OR] adjusted for study, 0.13 [95% confidence interval {CI}, 0.03-0.54]). This association remained after adjustment for maternal HIV viral load, receipt of antiretroviral prophylaxis, CD4(+) count, and other covariates. MTCT of HIV was not associated with the presence of GBV-C RNA (adjusted OR [aOR], 0.94 [95% CI, 0.62-1.42]) or GBV-C antibody (aOR, 0.90 [95% CI, 0.54-1.50]) in maternal samples.


CONCLUSIONS
Reduced MTCT of HIV was significantly associated with infant acquisition of GBV-C but not with maternal GBV-C infection. The mechanism for this association remains unknown.
Supapol
Wendy Bhanich
WB
Department of Public Health Sciences, University of Toronto,Toronto, Canada. supapol@cogeco.ca
Remis
Robert S
RS
Raboud
Janet
J
Millson
Margaret
M
Tappero
Jordan
J
Kaul
Rupert
R
Kulkarni
Prasad
P
McConnell
Michelle S
MS
Mock
Philip A
PA
Culnane
Mary
M
McNicholl
Janet
J
Roongpisuthipong
Anuvat
A
Chotpitayasunondh
Tawee
T
Shaffer
Nathan
N
Butera
Salvatore
S
D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use; D000914:Antibodies, Viral / Q000097:blood; D018791:CD4 Lymphocyte Count; D002648:Child; D005260:Female; D018178:Flaviviridae Infections / Q000635:transmission* / Q000821:virology*; D029407:GB virus C / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D005838:Genotype; D006678:HIV / Q000302:isolation & purification*; D015658:HIV Infections / Q000188:drug therapy / Q000635:transmission* / Q000821:virology; D006525:Hepatitis, Viral, Human / Q000635:transmission* / Q000821:virology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D009035:Mothers; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious; D015995:Prevalence; D012367:RNA, Viral / Q000097:blood; D013785:Thailand; D019562:Viral Load
D044966:Anti-Retroviral Agents; D000914:Antibodies, Viral; D012367:RNA, Viral