Parameters of immunotherapy: a retrospective study.

This is the second in a series of studies carried out on a group of 26 patients undergoing immunotherapy (IT) (9). The objective of this paper was to determine a new subclass of specific IgG, IgG1, so as to achieve comparable results with the previous study on IgG4. All patients in the study group were suffering from respiratory diseases and were all sensitized to Dermatophagoides pteronyssinus (DPT). They were subjected to IT for a period of 36 months. A 6 monthly control on the levels of anti-DPT specific IgE, anti-DPT specific IgG1 and anti-DPT specific IgG4 was done. Our results showed a level drop in anti-DPT specific IgE after 12 months of immunotherapy (p < 0.001) which was maintained in the 6 monthly controls which followed levels of anti-DPT (p < 0.01). Levels of anti-DPT specific IgG1 (p < 0.05) were lowered following 30 months of IT and were maintained till the end of treatment. The levels of anti-DPT specific IgG4 showed a level increase (p < 0.05) between 6 and 24 months of IT. The anti-DPT specific IgG4 level after 36 months of immunotherapy were lower than those obtained after 24 months of immunotherapy and were of no statistical significance. These values were statistically significant, however, when compared with the levels obtained prior to IT (p < 0.05). The IgG4/IgG1 ratio showed a gradual increase and reached extreme values after 24 months of IT (p < 0.05). There was no relationship between these values and the clinical evolution of each patient.