Immunologic Evaluation of Immediate Hypersensitivity to Cefaclor

PURPOSE: Cefaclor is widely prescribed for various infectious diseases. As its consumption increases, the number of hypersensitivity reactions to cefaclor has increased. This study aimed to evaluate the immunologic findings of immediate hypersensitivity to cefaclor. MATERIALS AND METHODS: We enrolled 47 patients with immediate hypersensitivity to cefaclor from Ajou University Hospital and Asan Medical Center. Serum specific IgE, IgG1, and IgG4 antibodies to cefaclor-human serum albumin (HSA) conjugate were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The most common phenotype was anaphylaxis (Group I, 78.7%), followed by urticaria (Group II, 21.3%). The detection of specific IgE, IgG1, and IgG4 to cefaclor-HSA conjugate by ELISA tended to be higher in Group I (40.5%, 41.7%, 21.6%) than in Group II (20.0%, 20.0%, 0%) with no statistical significance. Significant associations were found between specific IgE and IgG1 or IgG4 (p<0.001, p=0.019). ELISA inhibition tests showed significant inhibitions by both free cefaclor and cefaclor-HSA conjugate. For basophil activation tests in patients having no specific IgE antibody, the CD63 expression level on basophils increased with incubations of free cefaclor. CONCLUSION: The most common manifestation of immediate hypersensitivity to cefaclor was anaphylaxis, most of which was mediated by IgE; however, a non-IgE mediated direct basophil activation mechanism was suggested in a subset of anaphylaxis patients.

Basophil CD63 expression in the blood of the anaphylactic shock rat / 法医学杂志

OBJECTIVE@#To explore the value of flow cytometry in anaphylactic shock diagnosis by CD63 expression being detected using flow cytometry to conform the activation of basophils.@*METHODS@#Sixteen rats were randomly divided into two groups: control group and anaphylactic shock group. The model of anaphylactic shock rat with ovalbumin injection was established. CD63, CD45 and CD203c antibody combination, flow cytometry was employed to detected blood basophil CD63 expression. Immunofluorescence method was employed to observe the CD63 immunofluorescence staining in the rat lung tissue.@*RESULTS@#(1) Pure basophils were obtained by CD45 and CD203c gating. (2) The percentages of basophils CD63 were (17.34 +/- 2.04)% and (1.52 +/- 0.35)% in the experimental and control group, respectively. The differences between two groups were statistically significant (P < 0.01). (3) Compared with the control group, the expression of CD63 in basophils increased in anaphylactic shock lung tissue.@*CONCLUSION@#The detection of CD63 by flow cytometry could be the supplement of vivo allergic reactions and have good clinical value.

Studies of recombinant streptococcal pyrogenic exotoxin B/cysteine protease (rSPE B/SCP) in the skin of guinea pigs & the release of histamine from cultured mast cells & basophilic leukocytes.

BACKGROUND & OBJECTIVES: Streptococcal pyrogenic exotoxin B/streptococcal cysteine protease (SPE B/SCP) is considered to be one of the virulence factors of Streptococcus pyogenes (S. pyogenes) which causes serious diseases such as severe invasive infections and streptococcal toxic shock syndrome (STSS). There are no reports on the histamine releasing activity of SPE B/SCP from mast cells, although several biological activities have been studied. It is not clear whether SPE B/SCP have the superantigenic activity. We studied whether SPE B/SCP plays as a pathogenic factor in streptococcal infections and STSS through a histamine releasing activity. METHODS: Human mast cells and basophils were generated from CD34 positive cells isolated from cord blood and cultured in the presence of rIL-6, stem cell factor and/or rIL-3. The capacity of increasing capillary permeability of recombinant SPE B/SCP (rSPE B/SCP) was studied by using the skin of guinea pigs. Mitogenic activity to human T-cells of rSPE B/SCP was studied by incorporation of (3)Hthymidine. The levels of histamine in the plasma of patients with STSS and controls were measured by ELISA kit. RESULTS: rSPE B/SCP induced increased capillary permeability in the skin of guinea pigs, but both SPE A and SPE C did not exhibit such activity. Histamine was released from cultured human mast cells stimulated with rSPE B/SCP. The rSPE B/SCP did not exhibit mitogenic activity to human T-cells. Three of the 7 patients with STSS showed higher levels of plasma histamine than those of normal subjects. INTERPRETATION & CONCLUSION: The results suggested that increased capillary permeability and histamine release from mast cells induced by rSPE B/SCP might be involved in STSS and/or streptococcal infection of skin and mucous membrane.

One year observation of immunotherapy for Artemisia hay fever in China: a clinical and immunological study.

A controlled trial of one year immunotherapy was conducted in 50 Artemisia-sensitive hay fever patients (treatment group). From October 1985 to July 1986, all of the treatment group patients received one year regular injection of Artemisia pollen allergen extract totalling 30,000 protein nitrogen units (PNU). For these patients, symptom score indices of the posttreatment 1986 pollination season were compared with those from the pretreatment 1985 season and also with the scores of a similar group of 30 Artemisia-sensitive patients treated only with symptomatic medications during the 1986 season (control group). The 1986 symptom scores to the treatment group were significantly improved and the effective rate was 78%. Immunological study with the Human Basophil Degranulation Test (HBDT) showed a significant decrease in degranulation reactions after immunotherapy. Moreover, The decline of the HBDT positive rate in the treatment group was significantly greater in patients with improved symptoms than patients with unchanged symptoms. No difference was observed in basophil degranulation in those patients tested with a pollen-free plant extract, which was not applied in immunotherapy. The results suggested that immunotherapy could induce desensitization of basophils and that the induction might be allergen specific. Basophil desensitization may play an important role in the mechanism of immunotherapy.