Further production and characterization of antibodies reactive with pyrazolone derivatives.

A sensitive radioimmunoassay for pyrazolone derivatives has been developed. Anti-antipyrine antisera were produced in rabbits by repeated immunization with 4-succinamidoantipyrine coupled to bovine serum albumin. Less than 1 ng of antipyrine could be detected by this procedure. Various substituents on the carbon-4 position of the pyrazolone ring decreased the affinity for the antibody. The concentrations in ng of various pyrazolone derivatives required to inhibit [3H]antipyrine binding by 50% were: antipyrine, 6.8; aminopropylon, 8.5; sulpyrine, 35.5; isopropylantipyrine, 1320; and aminopyrine, 2820. The antibody showed no cross-reactivity with any other antipyretics such as pyrazolidine or aniline derivatives. The determination of antipyrine and sulpyrine concentrations in rat serum after i.p administration was also carried out.

Lymphocyte transformation test in fixed drug eruption.

Twenty-one patients with fixed drug eruption were studied with the lymphocyte transformation test. In no patient was there blast transformation when the responsible drug (1:10,000 dilution) was added to the lymphocyte culture. The addition to the lymphocyte culture of 0.4 ml of autologous serum, taken at the acme of the clinical reaction, produced blast transformation of the lymphocytes, and when the responsible drug (1:10,000 dilution) was added to this system, blast transformation increased by several times. The addition of the responsible drug to autologous serum obtained during clinical remission produced a minimal or negative response. These findings suggest that during fixed drug eruptions a blast transforming factor appears temporarily in the serum and increases its activity in the presence of the responsible drug. This factor spontaneously diminishes or disappears a few days after clinical exacerbation.

Monoclonal antibodies to 1-aminopyrene-DNA.

Monoclonal antibodies were obtained after fusion of mouse P3X63-AG.8.653 myeloma cells with spleen cells isolated from BALB/cCr mice immunized with denatured DNA modified by 1-nitrosopyrene reduced with sodium ascorbate (AP-d-DNA) and complexed electrostatically to methylated bovine serum albumin. Ten stable hybridoma lines have been isolated and characterized by enzyme-linked immunosorbent assay (ELISA). They all recognize 1-aminopyrene (1-AP)-modified DNA, but not free 1-nitropyrene or 1-aminopyrene. Antibody 11H2 is the most specific for AP-DNA showing no cross-reactivity with unmodified native DNA. It also recognizes 8-nitro-1-AP and 6-nitro-1-AP modified DNA. There was some low cross-reactivity with DNA modified by a benzo[a]pyrene diol epoxide and N-acetoxy-N-2-acetylaminofluorene. Competitive ELISA with antibody 11H2 reliably detected AP-DNA adducts formed when 1-nitropyrene was incubated with Salmonella typhimurium TA1538. By immunological methods, AP-DNA adducts were shown to be unstable to heat denaturation. This suggests that specific monoclonal antibodies to carcinogen-DNA adducts will be useful not only for detecting and quantitating carcinogen-DNA damage but also for probing adduct stability.

[T & B-lymphocytes and immunoglobulins of the serum in drug eruptions of immediate type (author's transl)]. / T & B-Lymphozyten sowie Serumimmonoglobuline bei Arzneimittelallergien vom Soforttyp.

Lymphocyte subpopulations and serum immunoglobulins of patients with drug-hypersensitivity were studied. The results are as follows: Lymphocyte subpopulations: decrease of the E-rosette forming cells was observed in both active and symptom free state. The number of IgE-bearing lymphocytes in patients with drug-allergy was higher than that of the controls. Serum-immunoglobulins: The IgE-level in the serum of patients with drug-allergy was higher in active state than afterwards, but still higher than in the controls but it was lower than in atopic dermatitis patients. The level of the other immunoglobulins was normal.

Amydopyrine pancytopenia: detection of leucocytotoxic antibodies by a 51Cr-release test.

Amydopyrine is known to cause agranulocytosis by an immunological mechanism [2]. However, pancytopenia due to amydopyrine is extremely rare and usually mild and transient [3]. This report describes a patient with severe pancytopenia presumably due to amydopyrine sensitivity. Granulocytotoxic and lymphocytotoxic antibodies were detected in the patient's serum using a 51Cr-release test.

Immune-mediated agranulocytosis related to drugs and their metabolites: mode of sensitization and heterogeneity of antibodies.

Two major unresolved problems in drug-related immune agranulocytosis are understanding the mechanism by which sensitization takes place in vivo, and verification of the diagnosis. Using a sensitive, competitive enzyme-linked immunoassay (ELISA) we were able to characterize the causative antibodies in 13 patients with drug-related agranulocytosis [metamizole (n = 5), penicillin (n = 5), dimethylaminophenazone (n = 1), propyphenazone (n = 1) and diclofenac (n = 1)]. Irrespective of the causative drug, the majority of patients appear to have developed autoantibodies (aab) in addition to drug-dependent antibodies (ddab) of the IgG and/or IgM classes. In all cases related to metamizole, and in the single case related to diclofenac, the ddab appeared to recognize only metabolites of the drug since they were reactive in the presence of ex vivo antigens (urine from individuals receiving therapeutic levels of the drugs), but not the native drugs. Only a few ddab were reactive with granulocytes pretreated with the drug (cell-drug complexes); the majority of ddab could not be detected unless the drug or ex vivo antigen was added to the incubation mixture as well as the solution used for subsequent washes. Our results indicate that drugs and/or their metabolites interact with target cells and thereby directly function as immunogenic haptens, even when the drugs do not bind tightly to the cells.