Replication study concerning the effects of homeopathic dilutions of histamine on human basophil degranulation in vitro
Adrian G. Guggisberg, Stephan M. Baumgartner, Cornelia M. Tschoppb Peter Heusser
Summary
Background: Various investigators have observed significant effects of highly diluted
histamine on human basophil degranulation in vitro, compared to corresponding
water controls. However, active and inactive dilution levels differed in most studies.
Objective: We aimed to reproduce former studies with flow-cytometry usingrig orously
controlled experimental conditions to minimise confoundingfactors.
Methods: In seven independent experiments, basophils of the same human donor
were incubated with diluted histamine (up to 10−34 M) or water controls and activated
with anti-IgE antibodies. Basophil activation was determined by using bicolour
flow-cytometry. Experiments were blinded and performed with a randomised
arrangement of the solutions on microtiter-plates.
Results: Histamine at the dilutions 10−2 M and 10−22 M was associated with a significant
inhibition of basophil degranulation (p = 0.018, Wilcoxon signed rank test) of
23.1% and 5.7%, respectively, if compared to ‘‘diluted’’ water treated in an identical
manner. However, if all controls were pooled, only histamine 10−2 M had a significant
effect. Significant effects were seen for row numbers of the microtiter plates.
Conclusion: We were not able to confirm the previously reported large effects of
homeopathic histamine dilutions on basophil function of the examined donor. Seemingly,
minor variables of the experimental set up can lead to significant differences
of the results if not properly controlled.