Evidence for a Peak Shift in a Humoral Response to Helminths: Age Profiles of IgE in the Shuar of Ecuador, the Tsimane of Bolivia, and the U.S. NHANES
2011

Age Patterns of IgE in Indigenous Populations and the U.S.

Sample size: 10357 publication 10 minutes Evidence: high

Author Information

Author(s): Blackwell Aaron D., Gurven Michael D., Sugiyama Lawrence S., Madimenos Felicia C., Liebert Melissa A., Martin Melanie A., Kaplan Hillard S., Snodgrass J. Josh

Primary Institution: University of California, Santa Barbara

Hypothesis

The age-profile of IgE levels varies across populations with different helminth infection rates.

Conclusion

The study found that IgE levels peak earlier in populations with higher helminth infections, suggesting a peak shift in immune response.

Supporting Evidence

  • Tsimane had the highest IgE levels (geometric mean = 8,182 IU/ml).
  • Shuar IgE levels were significantly higher than NHANES values.
  • Helminth infections were prevalent in Tsimane, with hookworm and Ascaris lumbricoides being the most common.
  • Age-patterning of IgE levels was consistent with the peak shift model.
  • Male participants had higher IgE levels than females across all populations.

Takeaway

Kids in places with lots of worms in their tummies have higher allergy-fighting proteins called IgE, and they reach their highest levels earlier than kids in the U.S.

Methodology

Total IgE levels were assessed in serum and dried blood spots, and age-patterns were examined using non-linear regression models.

Potential Biases

Potential biases may arise from differences in health care access and environmental factors among populations.

Limitations

The study lacks specific IgE data for helminth species in the Shuar and NHANES populations.

Participant Demographics

Participants included the Tsimane (n=832), Shuar (n=289), and U.S. NHANES (n=8,336) with varying ethnic backgrounds.

Statistical Information

P-Value

p<0.001

Confidence Interval

(1,691–39,582)

Statistical Significance

p<0.001

Digital Object Identifier (DOI)

10.1371/journal.pntd.0001218

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