[Risk factors of systemic allergic reactions caused by subcutaneous allergen immunotherapy].

Objective: To investigate the incidence and risk factors of systemic allergic reactions induced by subcutaneous immunotherapy (SCIT) in patients undergoing SCIT injections in Peking Union Medical College Hospital (PUMCH). Methods: This is a single center retrospective cohort study. Using the outpatient information system of PUMCH, the demographic information and injection-related reaction data of patients undergoing SCIT injection in Allergy Department of PUMCH from December 2018 to December 2022 were retrospectively analyzed to count the incidence and risk factors of systemic allergic reactions caused by SCIT. Mann-Whitney nonparametric test or chi-square test was used for single-factor analysis, and multiple logistic regression was used for multiple-factor analysis. Results: A total of 2 897 patients received 18 070 SCIT injections in Allergy Department during the four years, and 40 systemic allergic reactions occurred, with the overall incidence rate of 0.22%. The incidence of systemic allergic reaction was 0.37% when using imported dust mite preparation and 0.15% when using domestic multi-component allergen preparation. The risk factors significantly related with SCIT-induced systemic allergic reactions in patients using imported dust mite preparation were age less than 18 years old (OR=3.186,95%CI: 1.255-8.085), highest injection concentration (OR value could not be calculated because all patients with systemic reactions were injected with highest concentration), and large local reaction in previous injection (OR=22.264,95%CI: 8.205-60.411). The risk factors for SCIT-induced systemic allergic reactions in patients using domestic allergen preparation were 5 or more types of allergens (OR=3.455,95%CI: 1.147-10.402), highest injection concentration (OR=3.794,95%CI: 1.226-11.740) and large local reaction in previous injection (OR=63.577,95%CI: 22.248-181.683). However, SCIT injection in pollen allergic patients during the pollen season did not show a correlation with systemic allergic reaction. Conclusion: The incidence of SCIT-induced systemic allergic reactions was low in the Chinese patient population of this study. Patients with one or more risk factors, such as multiple allergen injection, highest injection concentration, large local reaction in previous injection, should be given high attention and vigilance against systemic allergic reactions.

[The clinical value of China Savin pollen extract used for skin prick test].

Objective:The aim of this study is to evaluate the effectiveness and safety of China Savin pollen extract which was used for skin prick test (SPT) in the diagnosis of China Savin pollen allergy. Method:Patients with diagnosis of allergic diseases were collected from Allergy Department of Peking Union Medical College Hospital. All patients were given SPT with China Savin pollen extract, and the mean wheal diameter (MWD) was measured after 15 minutes. Receiver operating characteristic curve (ROC) analysis was performed based on the results of serum specific immunoglobulin E (sIgE). The effectiveness of SPT in the diagnosis of China Savin pollen allergy was evaluated under different diagnostic cutoff values. Adverse events were also recorded to evaluate the safety. Result:A total of 1 029 patients were enrolled in this study without drop out case. There were 1 007 patients in full analysis set (FAS) and 765 patients in per protocol analysis set (PPS). The elimination rate was 25.66%. The area under the ROC curve of FAS is 0.814 (95%CI: 0.788-0.839); which of PPS is 0.829 (95%CI: 0.801-0.857). Based on the ROC curve of PPS, the optimal and the 95% specificity diagnostic cutoff values of MWD were 3.25 mm and 4.75 mm respectively. Based on different diagnostic cutoff value (3.00, 3.25 and 4.75 mm), the sensitivities of SPT with China Savin pollen extract were 0.740 0 (95%CI: 0.701 6-0.778 4), 0.700 (95%CI: 0.659 8-0.740 2) and 0.532 (95%CI: 0.488 3-0.575 7) respectively, whereas the specificity was gradually increased in sequence, which was 0.769 8 (95%CI: 0.719 1-0.820 5), 0.826 4 (95%CI: 0.780 8-0.872 0) and 0.950 9 (95%CI: 0.924 9-0.976 9) respectively. There were 7 adverse events observed among 6 patients (rate: 0.583%, 6/1 029). The manifestation was mild. There was no severe adverse event. Conclusion:SPT with China Savin pollen extract is an effective and safe tool for the diagnosis of China Savin pollen allergy. The effectiveness of diagnosis could be improved based on integration of medical history and different diagnostic threshold values of SPT.

[Application of temporary balloon occlusion of the abdominal aorta in the treatment of complete placenta previa complicated with placenta accreta].

Objective: To investigate the value of temporary balloon occlusion of the abdominal aorta in the treatment of complete placenta previa with placenta accreta. Methods: From January 2015 to February 2016, 24 cases of complete placenta previa with placenta accreta were treated with temporary balloon occlusion of the abdominal aorta(the study group)before cesarean, and 24 cases of complete placenta previa with placenta accreta did not receive balloon occlusion(the control group). The operation time, intraoperative blood loss, intraoperative blood transfusion volume, the perioperative hemoglobin level, the hysterectomy rate and the related complications were compared retrospectively.Also, the hospitalization time, the blood coagulation parameters after operation, including activated partial thromboplastin time(APTT), fibrinogen(FIB), D-Dimer and reperfusion injury parameters including creatine phosphokinase(CK), creatine phosphokinase isoenzyme(CK-MB), lactate dehydrogenase(LDH)and serum creatinine were compared between the 2 groups. Results: The blood loss[750 ml(400- 2 000 ml)vs 2 000 ml(1 500- 2 375 ml); Z=-3.214, P=0.001]and blood transfusion volume[200 ml(0-800 ml)vs 800 ml(0-1 200 ml); Z=- 2.173, P=0.030]in the study group were lower than in the control group. The hemoglobin difference between before and after operation in the study group was lower than the control group[(12.8±13.4)g/L vs(22.9±20.1)g/L; t=-2.041, P=0.047]. In the study group, there were still bleeding in 13 cases after releasing the balloon, 5 of them received uterine artery embolization, 5 cases received uterine artery ligation, and 3 cases received uterine packing. One case had venous thrombosis in the right lower limb. Two cases(8%,2/24)in the control group had hysterectomy, while none in the study group, there was no statistical significance(P= 0.489). Conclusions: Temporary balloon occlusion of the abdominal aorta can effectively reduce blood loss and blood transfusion in the treatment of complete placenta previa with placenta accreta, but there is still the risk of continuing bleeding after releasing the balloon. Other methods of hemostasis might be needed.

Update on treatment of hereditary angioedema.

Hereditary angioedema (HAE) is a rare disease characterized by recurrent, self-limiting episodes of swelling. New research and therapies have recently emerged and are now available; however, many physicians are not aware of the new developments in HAE. To update immunologists and other health care providers on new advances in HAE therapies, a PubMed, OVID and Google literature search were used to develop this manuscript. English language peer-reviewed angioedema articles were selected. High quality clinical trials were reviewed and summarized. Acute therapy in the past often consisted of symptom relief with narcotics, hydration and fresh frozen plasma (FFP). Androgens and FFP are frequently used despite multiple, significant side-effects. Newer therapies include C1-inhibitor - both human plasma derived and recombinant - as well as contact system modulators such as ecallantide and icatibant. These newer products can be used for treatment of acute attacks of HAE, and C1-inhibitors can also be used for prophylaxis. These disease-specific therapies have proven to work by placebo-controlled studies, have minimal adverse effects and can be utilized for the treatment of HAE.

Mutational spectrum and geno-phenotype correlation in Chinese families with hereditary angioedema.

BACKGROUND: Hereditary angioedema is a rare autosomal dominant disease, and its correlation between genotype and phenotype seems not to exist. So far, there are very few studies on Chinese population. We aimed to establish a Chinese genetic database of hereditary angioedema and investigated the potential correlation between genotype and phenotype. METHOD: All the eight exons and intron-exon boundaries of C1 inhibitor gene were detected in 48 unrelated families with HAE. The correlations between genotype and clinical parameters were evaluated by R statistical software. RESULTS: Thirty-five different mutations (25 of them were novel) and 7 SNPs (3 of them were novel) were identified. Significant difference was found in the level of C1 inhibitor antigen (P = 0.01793) between different groups of mutational types. The correlation between different groups of mutational types and the level of C1 inhibitor antigen (0.5047, P = 0.00027) was significant. The different groups of mutational types showed neither difference nor correlations of clinical parameters (severity score and the level of C1 inhibitor function). CONCLUSION: It appears that nonsense, frameshift, and mutations on Arg466 can cause lower level of C1 inhibitor antigen than missense and in-frame mutations; however, it does not affect severity of symptoms.

Erratum: 3,3'-(2,2'-Bi-1H-imidazole-1,1'-di-yl)dipropanamide. Corrigendum.

The list of authors in the paper by Zhi, Long, Chen & Ren [Acta Cryst. (2009), E65, o2008] is corrected and the acknowledgements are updated.[This corrects the article DOI: 10.1107/S1600536809028955.].

3,3'-(2,2'-Bi-1H-imidazole-1,1'-di-yl)dipropanamide.

In the title compound, C(12)H(16)N(6)O(2), the two imidazole rings are coplanar as a center of inversion exists midway along the C-C bond joining the two rings. In the crystal, inter-molecular N-H⋯O, N-H⋯N and C-H⋯O hydrogen bonds link adjacent mol-ecules into a two-dimensional layer structure parallel to (001).