Immunogenicity of recombinant @entity1 XXXX : biological features and clinical relevance.

@entity1 @entity19 @entity1358 @entity5041 @entity1892 @entity14 @entity1199 @entity978 @entity320
The immunogenicity of recombinant @entity1199 ( @entity5041 , EuroCetus, Amsterdam, Netherlands) was studied in seventy-six @entity1 receiving different subcutaneous immunotherapy regimens. @entity1 presented with progressive @entity1358 , @entity320 , @entity14 , @entity1892 , and @entity978 . An enzyme immunoassay (EIA) was employed to screen @entity1 for development of non-neutralizing antibodies against @entity5041 , antibody specificity was confirmed by a standard Western blot. Neutralizing serum activity against @entity5041 was detected using a standard CTLL @entity19 proliferation assay. Additionally, serum levels of soluble @entity1199 receptors and lymphocyte subsets expressing the CD56 natural killer (NK) associated antigen were measured. In a proportion of approximately 35% to 90% of the @entity1 treated, non-neutralizing antibodies against @entity5041 could be detected after all treatment courses were evaluated. Antibodies were of the IgG, IgM, IgA and IgD subtypes. None of the 76 patients exhibited serum neutralizing activity after one treatment course. Five @entity1 exhibited neutralizing anti- @entity5041 serum activity after two or more treatment courses of systemic @entity5041 . In three of these patients, antibodies neutralized both recombinant and natural @entity1199 . @entity1 developing neutralizing anti- @entity5041 antibodies, exhibited significantly lower serum sIL-2 receptor levels upon the emergence of serum neutralizing activity than patients without antibody. Additionally, NK cell associated CD56 positivity was significantly lower in @entity1 who exhibited neutralizing anti- @entity5041 serum activity than in @entity1 who did not. A significant decrease in levels of soluble @entity1199 receptors and CD56 NK cell positivity was observed, when comparing values prior to and after onset of serum neutralizing activity against @entity5041 . However, while emergence of neutralizing antibodies to @entity5041 diminished @entity5041 induced biological activation, it did not coincide with abrogation of treatment response.
