Respiratory exposure to diesel exhaust particles decreases the spleen IgM response to a T cell-dependent antigen in female B6C3F1 mice.

We investigated the systemic immunotoxic potential of respiratory exposure to diesel exhaust particles (DEP) in this study. Female B6C3F1 mice (approximately 8 weeks old) were exposed to increasing concentrations of DEP intratracheally, 3 times every two weeks, and sacrificed 2 or 4 weeks after the first exposure. The systemic toxicity and immune status in mice were evaluated. Mice exposed to DEP (1 to 15 mg/kg) showed no significant changes in body, spleen, or liver weights. Lung weights were increased in the mice exposed to 15 mg/kg DEP for 2 or 4 weeks. Except for a decreased platelet count, no significant alterations occurred in hematological parameters following DEP exposure. The number of splenic anti-sheep red blood cell (sRBC) IgM antibody-forming cells (AFC) decreased following DEP exposure for 2 weeks. This effect was less severe following 4 weeks of exposure and was only evident in the high dose group. Exposure to DEP also resulted in a significant decrease in the absolute numbers and the percentages of total spleen cells for total, CD4(+), and CD8(+) T cells, while the numbers of B cells and total nucleated cells in spleen were not significantly changed. The proliferative response of splenocytes to the T-cell mitogen, concanavalin A (ConA), as well as their production of IL-2 and IFN-gamma, was decreased dose-dependently following exposure of mice to DEP for 2 weeks, whereas proliferation was not changed in response to anti-CD3 monoclonal antibody. In summary, short-term respiratory exposure of mice to DEP resulted in systemic immunosuppression with evidence of T cell-mediated and possibly macrophage-mediated mechanisms.     

Review of select transplant subpopulations at high risk of failure from standard immunosuppressive therapy

Despite improvements in short-term graft and patient survival rates for solid organ transplants, certain subgroups of transplant recipients experience poorer clinical outcome compared to the general population. Groups including pediatrics, African-Americans, diabetics, cystic fibrosis patients, and pregnant women require special considerations when designing immunosuppressive regimens that optimize transplant outcomes. Problems specific to pediatric transplant recipients include altered pharmacokinetics of immunosuppressive drugs, such as cyclosporine (CsA) and tacrolimus (poor absorption, increased metabolism, rapid clearance), the need to restore growth post-transplantation, and a high incidence of drug-related adverse effects. African-Americans have decreased drug absorption and bioavailability, high immunologic responsiveness, and a high incidence of post-transplant diabetes mellitus. Diabetics and cystic fibrosis patients exhibit poor absorption of immunosuppressive agents, which may lead to underimmunosuppression and subsequent graft rejection. Pregnant women undergo physiologic changes that can alter the pharmacokinetics of immunosuppressives, thus requiring careful clinical management to minimize the risks of either under- or overimmunosuppression to mother and child. To achieve an optimal post-transplant outcome in these high-risk patients, the problems specific to each group must be addressed, and immunosuppressive therapy individualized accordingly. Drug formulation greatly impacts upon pharmacokinetics and the resultant level of immunosuppression. Thus, a formulation with improved absorption (e.g., CsA for microemulsion), higher bioavailability, and less pharmacokinetic variability may facilitate patient management and lead to more favorable outcomes, especially in groups demonstrating low and variable bioavailability. Other strategies aimed at improving transplant outcome include the use of higher immunosuppressive doses, different combinations of immunosuppressive agents, more frequent monitoring, and management of concurrent disease states.     

Immunization of renal transplant recipients with pneumococcal polysaccharide vaccine

BACKGROUND: Streptococcus pneumoniae, a common pathogen leading to pneumonia, is a cause of morbidity and mortality in immunosuppressed patients. Vaccination against this agent can be recommended for immunosuppressed patients, including those with chronic renal failure, nephrotic syndrome and renal transplant recipients; however, a diminished immune response and loss of protective antibodies have been observed. PATIENTS AND METHODS: In our prospective study, the efficacy and side effects of polyvalent pneumococcal vaccination were investigated in renal transplant recipients. A total of 21 patients (6 female, 15 male) with well-functioning renal allografts, who had transplant surgery at least 2 months before, were included in the study. The patients were stratified according to the immunosuppressive protocol and 8 received double, while 13 received triple, immunosuppressive agents. After obtaining basal serum samples, all cases were vaccinated with the 0.5 mL intramuscular administration of polyvalent polysaccharide pneumococcal vaccine (Pneumo 23 Pasteur Merieux, lot No: K 1131). RESULTS: Following a mean of 6 wk in all patients and also a mean of 12 wk in 12 patients, serum samples were again obtained to measure pneumococcal antibodies. Antibody titers following 6 and 12 wk of vaccination were significantly higher, as compared with basal values in all patients, except one. These titers did not show any statistically significant difference between double and triple therapies. There was no significant difference between the 12th and 6th wk postvaccination antibody titers. No systemic or local adverse effects were observed. CONCLUSION: Pneumococcal vaccination is safe and effective in patients with well-functioning renal allografts, at least in the short term. This vaccination policy may be useful for preventing invasive pneumococcal disease in immunosuppressed patients.     

A prospective economic evaluation of basiliximab (Simulect) therapy following renal transplantation

BACKGROUND: Immunoprophylaxis with basiliximab (Simulect), an anti-interleukin-2-receptor (anti-IL-2R; CD25) chimeric monoclonal antibody, has been demonstrated to significantly reduce the incidence of acute cellular rejection in adult renal allograft recipients (32% vs. placebo, p < 0.01). METHODS: An economic evaluation was conducted as part of a U.S. multi-center, randomized, double-blind, placebo-controlled clinical trial comparing basiliximab plus dual immunosuppressive therapy (cyclosporine modified [Neoral] and corticosteroids) to dual therapy alone. Healthcare resources utilized by the 346 subjects in the 'intent-to-treat' population were prospectively collected over the 1-yr study period. Direct medical costs were determined for all hospitalizations, outpatient provider visits, procedures (excluding the initial transplant procedure), laboratory and diagnostic tests, and immunosuppressants, including basiliximab when administered. RESULTS: Total first-year medical costs were lower for the basiliximab group than for the placebo group ($28 927 vs. $32 300, difference = $3373). although this difference was not statistically significant. First-year hospital costs for treating acute rejection were also lower for the basiliximab group ($9328 vs. $10761, difference = $1433); however, this difference did not achieve statistical significance. Importantly, the efficacy analysis demonstrated a significant reduction in the incidence of acute rejection (38 vs. 55%, p < 0.01) in the basiliximab arm, and this was accomplished without increasing the overall cost of care. Fewer basiliximab-treated patients (8 vs. 15%,, p = 0.03) were hospitalized. This observation suggested less serious illness and reduced treatment costs among basiliximab-treated patients, because the overall incidence of infection was similar between the groups. The adverse event profile of patients receiving basiliximab was clinically and economically indistinguishable from that of those treated with placebo. CONCLUSION: Induction immunosuppression with basiliximab, combined with cyclosporine modified and corticosteroids, was therapeutically beneficial and contained medical costs during the initial post-transplant year.     

雷公藤属药用植物的研究进展

雷公藤属药物植物具有抗炎、抗免疫、抗肿瘤、抗H IV等多种药理活性。临床上广泛用于治疗类风湿性关节炎、慢性肾炎等自身免疫性疾病。其化学成分复杂,主要包括倍半萜类(包括倍半萜生物碱)、二萜类、三萜类和少量木质素等。综述近年来雷公藤属药用植物化学成分、药理作用等方面的研究成果,指出雷公藤类药物具有广阔的发展前景。     

醋酸舍莫瑞林的免疫活性研究

目的　观察醋酸舍莫瑞林对免疫抑制模型小鼠免疫功能的调节作用。方法　通过给小鼠腹腔注射免疫抑制剂环磷酰胺 ,建立免疫功能低下模型 ,腹腔注射醋酸舍莫瑞林进行体内拮抗实验。测定胸腺指数、脾脏指数、巨噬细胞吞噬功能、T淋巴细胞的增殖指数、耳肿胀度、血清IL - 2的含量。结果　醋酸舍莫瑞林 ( 0 18,0 36mg/kg)能显著提高被环磷酰胺抑制的胸腺和脾脏重量 (P <0 0 1) ;使巨噬细胞吞噬功能明显增加 ,并能拮抗环磷酰胺对小鼠脾脏T淋巴细胞增殖、二硝基氯苯 (DNCB)诱导的迟发型超敏反应和IL - 2产生的免疫抑制作用。结论　醋酸舍莫瑞林能拮抗环磷酰胺所引发的免疫抑制作用     

肾移植受者霉酚酸治疗药物监测

目的研究霉酚酸酯(MMF)的代谢产物霉酚酸(MPA)的药代动力学特征,并形成简化的MPA血浆浓度-时间曲线下面积(AUC)计算公式。方法64例肾移植受者均接受MMF 2 g/d联合环孢素A(CsA)和强的松的三联免疫抑制治疗。在术后2周采用HPLC法,测定服药前、服药后0.5、1、1.5、2、4、6、8、10、和12 h的血浆MPA浓度。采用药理学专用软件计算MPAAUC0-12 h,并以多元逐步回归分析的方法得出适合中国人群的MPA AUC0-12 h简化计算公式。结果64例肾移植受者的药代动力学参数有显著的个体差异。MPA AUC0-12 h平均值为(54.62±14.51)mg.h/L(24.01~02.3 mg.h/L)。MPA谷值浓度(C0)与MPA AUC0-12 h的相关性差(r2=0.03)。采用3个时间点取样(C0.5、C2、C8),得出MPA AUC的简化计算公式:AUC=10.96 0.56×C0.5 2.18×C2 7.86×C8。该公式MPA AUC的预测值与MPA AUC0-12 h的相关性好(r2=0.87);预测值的绝对误差为(7.41±6.23)%(0.27%~34.7%);在60例(93%)病人,AUC预测误差在MPA AUC0-12 h的±15%;B land和A ltm an分析显示平均预测误差为±5.24 mg.h/L。结论本组肾移植受者中,MPA的药代动力学参数呈现较大的个体差异,并有异于白种人群;根据本组临床监测数据,得出取样点少(3个时间点)、预测效果好的MPA AUC简化计算公式,并推荐应用于中国肾移植受者MPA的治疗药物检测。     

树突状细胞在感染性疾病免疫抑制中的作用

近年来越来越多的实验证明,DC不但有强大的免疫激活功能,而且在一些感染性疾病免疫抑制状态中DC发挥了重要作用,使感染向重症发展或病原体在体内广泛播散。本文将对DC在一些感染性疾病中免疫抑制方面的研究进展进行综述。     

中华鼢鼠骨提取物对淋巴细胞转移因子和白细胞介素-1的影响

目的观察中华鼢鼠骨提取物对完全弗氏佐剂(FCA)介导大鼠超敏反应性炎症免疫机能的影响.方法采用免疫学实验方法,检测受试动物淋巴细胞转移因子(TF)和白细胞介素-(IL-1)的水平.结果中华鼢鼠骨提取物能降低由FCA介导的大鼠超敏反应性炎症时所升高的IL-1和TF的水平,并能降低其淋巴细胞转化率.结论中华鼢鼠骨提取物对由FCA所介导的大鼠佐剂性关节炎的抑制作用,与抑制IL-1的生成以及免疫抑制作用有关.