Abstract: ObjectiveTo explore mechanism of adverse drug reactions induced by Shuanghuanglian for injection (SHLI) and further evaluate the immunosensitizing potential of SHLI using reporter antigen popliteal lymph node assay (RA-PLNA) in BALB/c mice. MethodsSPF female BALB/c mice (7~8 weeks old at the onset of the experiment), were randomly assigned into control (Veh), 1 mg D-Penicillamine hydrochloride (D-pen), 1 mg (L) and 5 mg (H) SHLI group. There are 4 groups and each group has 6 animals. Articles, respectively mixed with 10 μg Trinitropheny-Ovabumin (TNP-OVA), were injected subcutaneously into right hind foot pad of mice in 50 μL volume. On day 7 after injection, animals were sacrificed, the untreated and treated lateral popliteal lymph node (PLN) were isolated, weighed and prepared into single-cell suspensions respectively, and then PLN weight index (WI) and cells index (CI) were calculated. RA-PLNA responses were observed. Trinitrophenyl-specific antibody forming cell (AFC) and the number of lymphocyte and macrophages in PLN were determined by Enzyme-linked immunospot assay (Elispot) and flow cytometry, respectively. When SHLI mixed with TNP-Ficoll using some another mice, the method is the same as TNP-OVA. Results5 mg SHLI mixed with TNP-OVA or TNP-Ficoll induced positive reaction in RA-PLNA. However, only when 5 mg SHLI co-injected with TNP-OVA, TNP-specific AFC were observed in Elispot assay. Simultaneously, the number of macrophages in PLN increased in flow cytometry. Moreover, whether 5 mg SHLI with TNP-Ficoll or 1 mg SHLI mixed with TNP-OVA or TNP-Ficoll failed to induce TNP-specific reaction. ConclusionSHLI lacked the intrinsic capacity to sensitize or stimulate immune responses in BALB/c mice. This may imply that ADR induced by SHLI in clinic was mainly a non-IgE-mediated anaphylactoid reaction rather than IgE-mediated hypersensitivity reactions.

Key words: reporter antigen popliteal lymph node assay, Shuanghuanglian for injection, hypersensitivity reactions.