The effect of maternal helminth infection on maternal and neonatal immune function and immunity to tuberculosis.
BACKGROUND
M. tuberculosis and helminth infection each affects one third of the world population. Helminth infections down regulate cell mediated immune responses and this may contribute to lower efficacy of BCG vaccination and higher prevalence of tuberculosis.


OBJECTIVE
To determine the effect of maternal helminth infection on maternal and neonatal immune function and immunity to TB.


METHODS
In this cross sectional study, eighty five pregnant women were screened for parasitic and latent TB infections using Kato-Katz and QFT-GIT tests, respectively. IFN-γ and IL-4 ELISpot on Cord blood Mononuclear Cells, and total IgE and TB specific IgG ELISA on cord blood plasma was performed to investigate the possible effect of maternal helminth and/or latent TB co-infection on maternal and neonatal immune function and immunity to TB.


RESULTS
The prevalence of helminth infections in pregnant women was 27% (n = 23), with Schistosoma mansoni the most common helminth species observed (20% of women were infected). Among the total of 85 study participants 25.8% were QFT-GIT positive and 17% had an indeterminate result. The mean total IgE value of cord blood was significantly higher in helminth positive than negative women (0.76 vs 0.47, p = 0.042). Cross placental transfer of TB specific IgG was significantly higher in helminth positive (21.9 ± 7.9) than negative (12.3 ± 5.1), p = 0.002) Latent TB Infection positive participants. The IFN-γ response of CBMCs to ESAT-6/CFP-10 cocktail (50 vs 116, p = 0.018) and PPD (58 vs 123, p = 0.02) was significantly lower in helminth positive than negative participants. There was no significant difference in IL-4 response of CBMCs between helminth negative and positive participants.


CONCLUSIONS
Maternal helminth infection had a significant association with the IFN-γ response of CBMCs, total IgE and cross placental transfer of TB specific IgG. Therefore, further studies should be conducted to determine the effect of these factors on neonatal immune response to BCG vaccination.
Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia; Department of Medical Laboratory Sciences, Addis Ababa University, Addis Ababa, Ethiopia; Mekelle University, Mekele, Ethiopia.
Dawit
D
Gebreegziabiher
Department of Medical Laboratory Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
Kassu
K
Desta
Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia; Department of Medical Laboratory Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
Girmay
G
Desalegn
Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia.
Rawleigh
R
Howe
Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia.
Markos
M
Abebe
D000328:Adult; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D000909:Antibodies, Helminth / Q000276:immunology*; D003430:Cross-Sectional Studies; D005002:Ethiopia; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D006801:Humans; D007231:Infant, Newborn; D007371:Interferon-gamma / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008431:Maternal-Fetal Exchange / Q000276:immunology*; D009163:Mycobacterium bovis / Q000276:immunology; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000097:blood / Q000276:immunology*; D012550:Schistosoma mansoni / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000276:immunology*; D014376:Tuberculosis / Q000097:blood / Q000276:immunology*
D000907:Antibodies, Bacterial; D000909:Antibodies, Helminth; C573415:IFNG protein, human; C508598:IL4 protein, human; D015847:Interleukin-4; D007371:Interferon-gamma