Flow cytometric analysis of the inhibition of human basophil activation by histamine high dilutions - a replication study

Background: Inhibition of human basophil activation by highly diluted histamine was reported to be a reliable experimental model to examine biological effects of high dilutions. However, independent replications did not always yield concordant results. Aims: We aimed at performing an independent replication of a former study [1] using rigorously controlled experimental conditions to minimise confounding factors. Materials and Methods: In 20 independent experiments, human basophils were treated with highly diluted histamine (15cH, 16cH, corresponding to 10-30-10-32 M) prior to activation by fMLP (formyl-methionyl-leucyl-phenylalanine peptide). Controls were treated with analogously diluted water (15cH, 16cH). The dilutions were prepared freshly for each experiment in deionised water by successive steps of centesimal dilution and agitation (10 s vortex at high speed). Highly diluted samples were blinded and randomised. All samples were set in triplicates. Activated basophils were determined by flow cytometry using anti-CD203c. 20 independent systematic negative control (SNC) experiments were carried out to investigate possible systematic errors. Results: No difference in basophil activation was observed between the highly diluted histamine samples and the highly diluted water controls. There was no evidence for a blood donor specificity of the results. The SNC experiments demonstrated the stability of the test system. Experimental variability within and between experiments was slightly reduced for the highly diluted histamine samples. Discussion: This study was designed as an independent reproduction of a former study [1]. Though we strictly adopted the experimental procedure described in [1], our results do not confirm the large inhibitory effects observed for histamine 15cH and 16cH. This lack of reproducibility might be due to minor differences in the experimental design, such as blinding and randomising of the samples, which we chose to perform in order to reduce the possibility of artifacts but was omitted in the former study. Conclusions: Laboratory independent replication of homeopathic basic research experiments is still a challenge. Assuming that the results formerly obtained with this model were not due to systematic errors, the quest identifying the crucial factors for successful reproducibility is open for future research. Keywords: Human basophils; histamine; high dilutions; flow cytometry Reference: [1] Sainte-Laudy J, Belon P. Improvement of flow cytometric analysis of basophil activation inhibition by high histamine dilutions. A novel basophil specific marker: CD 203c. Homeopathy. 2006;95:3-8.

Clinical implication of detecting sensitization to iodinated radiocontrast media in the basophil activation test by flow cytometry

The use of iodinated radiocontrast media is necessary for visualization. A number of patients have adverse effects of various nature and severity when these drugs are administered. Routine allergy tests do not provide adequate diagnosis of reactions to drugs in this group. The aim of this work is to assess the capabilities of the basophil activation test to confirm sensitization to non-ionic iodinated radiocontrast media, as well as to select a safe alternative drug in patients with a burdened history. Basophil activation test by flow cytometry was performed in 184 patients The Nikiforov Russian Centre of Emergency and Radiation Medicine» EMERCOM of Russia and 32 volunteers using ultravist, omnipack, and optiray. The presence of sensitization was assessed based on the basophil activation index, as well as spontaneous and anti-IgE antibody-induced activation of basophils and the population of T-lymphocytes type 2 immune response. The volunteers showed no sensitization to iodinated radiocontrast media. In patients with a medium degree of hypersensitivity reaction in vivo, in vitro sensitization to drugs was detected 4 times more often than in patients with a mild degree (51% versus 13.5%). In patients with systemic reactions to the administration of a known drug, in vitro sensitization was confirmed in 86% of cases, while the frequency of detection of sensitization to drugs did not differ. Spontaneous activation of basophils in patients and type 2 T-lymphocytes were 2 times higher than in volunteers. Patients were more likely to have low (less than 30%) activation of basophils for anti-IgE antibodies. The specificity of the basophil activation test with iodinated radiocontrast media was 100% with a sensitivity of 94.1%. Most patients were able to select a non-sensitizing contrast. Inclusion in the algorithm of spontaneous and anti-IgE antibody-induced activation of basophils and a population of T-lymphocytes type 2 immune response will allow the doctor to carry out a personalized approach to the management of patients with a burdened history.

Efficacy of mite allergen immunotherapy in allergic rhinitis and the immune synergistic effect on cross-allergens

Aim: To compare the efficacy of single- and double-species mite allergen immunotherapy. Materials and methods: An open, pseudo-randomized, controlled study was conducted (n = 125 allergic rhinitis patients). The primary end point involved the visual analogue scale. Secondary end points included a basophil activation test and serum specific IgE and IgG4 assays. Results: Visual analogue scale analysis indicated considerable reductions in both groups. Both treatments improved quality of life and induced sIgG4 antibody production. Basophil activation and serum IgE inhibition were not evident in either treatment. Neither treatment displayed an early stage immune synergistic effect on cross-allergens. Conclusions: Both treatments were effective against allergic rhinitis, and statistical differences were not observed. Future studies may require long-term, large-scale research.