Eletters

Topic:

Nitric oxide in human anaphylaxis

Giovanni Rolla | grolla@mauriziano.it

Allergy and Clinical Immunology - University of Torino - ASO Ordine Mauriziano Umberto I - Torino

Charles J. Lowenstein and Thomas Michel wonder, in their commentary to the Cauwels’ article, whether NO mediates hypotension following anaphylaxis in humans as well. Very recently we measured high level of exhaled NO during anaphylaxis induced by specific bee-venom immunotherapy in a bee-keeper (1). The other common causes of increased exhaled NO, including asthma, allergic rhinitis or recent respiratory tract infection (2) were excluded. We suggest that the increased production of NO by respiratory tract in anaphylaxis mirrors increase in NO production by systemic circulatory system, as suggested by the relationship between exhaled NO and dialysis-induced hypotension (3). Our observation lends support to the hypothesis that NO plays an important role in human anaphylaxis and that NO-inhibiting drugs could theoretically be useful in the most severe cases refractory to epinephrine treatment (4)

1 – Rolla G, Nebiolo F, Guida G, Heffler E, Bommarito L, Bergia R. Increased exhaled nitric oxide during human anaphylaxis. Ann Allergy Asthma Immunol 2006; 97: 264-5.
2 – Ricciardolo FL, Sterk PJ, Gaston B, Folkerts G. Nitric oxide in health and disease of the respiratory system. Physiol Rev 2004; 84: 731-765.
3 – Raj DS, Vincent B, Simpson K, Sato E, Jones KL, Welbourne TC et al. Hemodynamic changes during hemodialysis : role of nitric oxide and endothelin. Kidney Int 2002; 61: 697-704.
4 – Oliveira Neto AM, Duarte NM, Vicente WV, Viaro F, Evora PR. Methylene blue: an effective treatment for contrast medium-induced anaphylaxis. Med Sci Monit 2003; 9: CS102-CS106.