Importance of IgG4 determination in in vitro immunotherapy follow-up of inhalant allergens.

Choosing the right parameters to recommend immunotherapy in allergologic diagnosis is very important.

Therefore, other parameters which are independent of the improvement of clinical manifestations and which indicate the evolution of asthma are very useful. Although a decrease in skin reactions was observed in 20% to 25% of patients in previous studies, since the in vitro techniques appeared, their evolution has been observed. Total and antigen-specific IgE evolution, as well as histamine release from basophils, in immunotherapy were followed as we had presented in previous studies. In this work, we studied 151 patients with asthma and rhinosinusitis, 70 of whom were sensitive to Lolium perenne and 81 to Dermatophagoides pteronyssinus. The parameters mentioned above were used, and the patients underwent immunotherapy at three different concentrations depending on the degree of sensitization. The standard concentration was used in the first group; those patients with very high values in radioallergosorbent test (RAST) and histamine release test (HRT) were given the concentration 1:2; and lastly, the largest group of patients, who presented the highest sensitization both in vivo and in vitro, were given the concentration 1:10.

As a complement to the mentioned in vitro techniques, the antigen-specific IgG4 determination (blocking antibody) was also evaluated. As we observed in previous studies, skin test, total IgE, antigen-specific IgE and HRTs showed no significant modifications in any of the three groups, in spite of the very positive clinical evolution over the 6 years. Regarding IgG4 follow-up in pollinic patients, a very significant increase was observed, reaching its highest value after 6 years, at standard concentration and with an increase of 49.4%. In conclusion, we think that antigen-specific IgG4 is the only easily available and suitable parameter existing for immunotherapy follow-up.

CITA DEL ARTÍCULO  J Investig Allergol Clin Immunol. 1998 Nov-Dec;8(6):333-9