[Antibodies to D-penicillamine in patients with chronic polyarthritis--diagnostic aid in undesired and insufficient drug effects?].

Antibodies to D-penicillamine (DPA) were determined in 25 patients with classic rheumatoid arthritis being treated with DPA. Positive results were found before and during therapy with DPA. Antibodies were found in seven out of ten patients without the desired therapeutic effects; in five cases before starting the therapy. It is hypothesized that antibodies against drugs are heterogeneous and influence the effect of the drugs, e.g. inhibition of the desired effect and stimulation of an undesired (adverse) reaction.