The values of nasal provocation test and basophil activation test in the different patterns of ASA/NSAID hypersensitivity

Background: The oral provocation test (OPT) is the current gold standard to diagnose aspirin hypersensitivity syndrome although it is time-consuming and contains some systemic risks. Other reliable methods with lower side effects and shorter test duration are being investigated. Objective: The purpose of this study was to evaluate the efficacy of the nasal provocation test (NPT) and the basophil activation test (BAT) in the diagnosis of different subtypes of aspirin sensitivity. Methods: Thirty aspirin sensitivity patients with cutaneous and respiratory manifestations underwent NPT and BAT with lysine-ASA. NPT result was interpreted as recommended in EAACI/GA2LEN guidelines and receiver operating characteristic analysis of BAT was performed by using 15 NSAIDs tolerant volunteers as a control group. Results: NPT was positive in 60% (18/30) of patients and BAT was positive in 76.7% (23/30) of patients. The incubation of basophils with 0.31mg/ml of lysine-aspirin and using 4.6% activated basophils gives the best predictive values to diagnose aspirin sensitivity. The combination of both tests yielded positive results in 80% and 93.3% of aspirin-induced cutaneous and respiratory patterns. The agreement between NPT and BAT results was 63.3%. Conclusions: NPT and BAT are beneficial to detect patients with aspirin sensitivity. The combination of both tests have additional diagnostic values; less time-consuming than OPT and their complications are negligible. A reliable alternative method with minimum side effects is needed to diagnose aspirin sensitivity in suspected patients who have contraindications for OPT(AU)

The values of nasal provocation test and basophil activation test in the different patterns of ASA/NSAID hypersensitivity.

BACKGROUND: The oral provocation test (OPT) is the current gold standard to diagnose aspirin hypersensitivity syndrome although it is time-consuming and contains some systemic risks. Other reliable methods with lower side effects and shorter test duration are being investigated. OBJECTIVE: The purpose of this study was to evaluate the efficacy of the nasal provocation test (NPT) and the basophil activation test (BAT) in the diagnosis of different subtypes of aspirin sensitivity. METHODS: Thirty aspirin sensitivity patients with cutaneous and respiratory manifestations underwent NPT and BAT with lysine-ASA. NPT result was interpreted as recommended in EAACI/GA2LEN guidelines and receiver operating characteristic analysis of BAT was performed by using 15 NSAIDs tolerant volunteers as a control group. RESULTS: NPT was positive in 60% (18/30) of patients and BAT was positive in 76.7% (23/30) of patients. The incubation of basophils with 0.31 mg/ml of lysine-aspirin and using 4.6% activated basophils gives the best predictive values to diagnose aspirin sensitivity. The combination of both tests yielded positive results in 80% and 93.3% of aspirin-induced cutaneous and respiratory patterns. The agreement between NPT and BAT results was 63.3%. CONCLUSIONS: NPT and BAT are beneficial to detect patients with aspirin sensitivity. The combination of both tests have additional diagnostic values; less time-consuming than OPT and their complications are negligible. A reliable alternative method with minimum side effects is needed to diagnose aspirin sensitivity in suspected patients who have contraindications for OPT.

Induction of inducible CD4+CD25+Foxp3+ regulatory T lymphocytes by porcine reproductive and respiratory syndrome virus (PRRSV).

Increases in numbers or activities of regulatory T lymphocytes (Tregs) have been linked to the establishments of several persistent infections. It has been previously shown that porcine reproductive and respiratory syndrome virus (PRRSV) can negatively modulate the host immune responses, resulting in persistent infection and secondary immunodeficiency. Recently, the existence of porcine CD4(+)CD25(+) Tregs has been demonstrated. We investigated the effect of PRRSV on the CD4(+)CD25(+) Tregs. The CD4(+)CD25(+)Foxp3(+) T lymphocytes in the peripheral blood mononuclear cells (PBMCs) were identified, using the anti-human anti-Foxp3 monoclonal antibody. In vitro culture of porcine PBMC in the presence of PRRSV, but not classical swine fever virus, significantly increased the numbers of Foxp3(+) lymphocytes, particularly in the CD4(+)CD25(high) subpopulation. The time-course study revealed that PRRSV significantly increased the numbers of viral-specific CD4(+)CD25(high)Foxp3(+) subpopulation in the culture starting from 12h through the end of the observation period. Consistent to the results obtained by flow cytometry, enhanced Foxp3 gene expression was observed in the PBMC cultured with PRRSV in a time-course manner. The presence of monocyte-derived DC in the co-culture significantly enhanced the induction of CD4(+)CD25(+) Foxp3(+) T lymphocytes. The PRRSV-induced CD4(+)CD25(high) T lymphocytes exhibited suppressive activity when co-cultured with PHA-activated, autologous peripheral blood leukocytes, indicating the suppressive activity of the PRRSV-specific Tregs. In addition, PRRSV exposure significantly increased the numbers of PRRSV-specific CD4(+)CD25(+)Foxp3(+) subpopulation in the PBMC of infected pigs at 10 days post-infection. In summary, the results indicated that PRRSV could increase the numbers of viral-specific, inducible regulatory T lymphocytes in the porcine PBMC, both in vitro and in vivo. The findings suggested the novel immunomodulatory mechanism induced by PRRSV.

Production and immunogenicity of hypoallergenic codon-optimized DNA vaccine encoding mature Der p 1 allergen.

BACKGROUND: Genetic vaccination with plasmid DNA encoding allergens is a promising potential approach for the treatment or prevention of allergy. Nonetheless, because the allergens expressed can display immunoglobulin (Ig) E reactivity, methods to deliver hypoallergenic variants can minimize the risk of type 2 helper (T(H)2) cell priming after DNA immunization. METHODS: A humanized synthetic gene encoding mature Dermatophagoides pteronyssinus group 1 (Der p 1) allergen was cloned into the pHIS expression vector carrying unmethylated CpG 2006 (CpG 2006) motif but devoid of signal sequence. The immunogenicity of this DNA construct was compared in naïve mice with that of recombinant ProDer p 1 protein adjuvanted with alum. RESULTS: Codon optimization of the cDNA encoding mature Der p 1 markedly improved allergen expression. Mature Der p 1, expressed intracellularly in Human Embryonic Kidney 293 cells (HEK 293 cells) transfected with codon-optimized Der p 1 cDNA (pHIS-mHuDer p 1), was shown to be hypoallergenic as it displayed no IgE reactivity. Intradermal vaccinations of naïve Balb/C mice with pHIS-mHuDer p 1 elicited an allergen-specific T(H)1 response characterized by the production of specific IgG2a, a very low amount of specific IgG1, and no specific IgE. Lipoplex formulation with cationic liposome composed of lecithin, N-[1-(2,3-Dioleoyloxy)propyl]-N,N,N-trimethylammonium methylsulfate (DOTAP) and cholesterol not only accelerated the induction of T(H)1 response but also increased its intensity. CONCLUSION: A codon-optimized DNA vaccine encoding mature Der p 1 in a lipoplex formulation could represent a promising hypoallergenic vaccine candidate for safer immunotherapy against house dust mite allergy.

Negative impact of porcine reproductive and respiratory syndrome virus infection on the efficacy of classical swine fever vaccine.

Recent findings suggest that porcine reproductive and respiratory syndrome virus (PRRSV) possesses immunomodulatory properties. To investigate the effect of PRRSV infection on classical swine fever (CSF) vaccine efficacy, 17-day-old pigs were divided into five groups. The experimental group was infected with a Thai PRRSV (US genotype) a week before CSF vaccination and challenged with a virulent CSF virus (CSFV) 3 weeks following vaccination. The control groups received no PRRSV infection, no CSF vaccination, no CSF challenge, or in combination were included. The results demonstrated that PRRSV infection significantly inhibited host immune response that resulted in vaccination failure in the subsequent CSFV exposure. Following CSF challenge, the PRRSV-infected, vaccinated pigs exhibited clinical, virological and pathological features resembled to those of the non-vaccinated groups. The findings indicated that CSF immunization during an acute phase of PRRSV infection could result in vaccination failure.

The kinetics of cytokine production and CD25 expression by porcine lymphocyte subpopulations following exposure to classical swine fever virus (CSFV).

Surface expression of IL-2R-alpha (CD25) is widely used to identify activated lymphocyte populations, while interferon-gamma (IFN-gamma) levels have been shown to be a good indicator of cell-mediated immunity (CMI) in pigs. To investigate the relationship between these two parameters, we developed an intracellular cytokine-staining assay and studied the kinetics of cytokine (IFN-gamma and interleukin-10, IL-10) production relative to CD25 expression in porcine lymphocyte subpopulations, following immunization with a classical swine fever (CSF) vaccine. The number of activated memory T cells (CD4(+)CD8(+)CD25(+) cells) increased slightly in the peripheral blood mononuclear cell (PBMC) population soon after vaccination, then diminished within a few weeks. The number of activated cytotoxic T cells (CD4(-)CD8(+)CD25(+) cells) peaked approximately 2 weeks after the memory population. Although the number of IFN-gamma producing cells detected in this experiment was relatively low, the CD4(+)CD8(+) T cells were major IFN-gamma producers in the PBMCs throughout the experiment. In another experiment, CSF-vaccinated pigs were challenged with a virulent classical swine fever virus (CSFV), and the kinetics of CD25 expression and cytokine productions were monitored. Following exposure to the virus, the number of IFN-gamma producing cells in the PBMCs increased markedly in both the vaccinated and unvaccinated groups. The CD4(-)CD8(+) cells were major IFN-gamma producing cells in vaccinated pigs, while both CD4(+)CD8(+) and CD4(-)CD8(+) populations contributed to the IFN-gamma production in the control group. Interestingly, the enhanced IFN-gamma production was not associated with the upregulation of CD25 expression following the CSFV challenge. In addition, exposure to the virulent CSFV significantly increased interleukin-10 production by the CD4(-)CD8(+) populations in PBMCs of the unvaccinated pigs. Taken together, our results indicated that CD25 expression and IFN-gamma production were not tightly associated in porcine lymphocytes. In addition, the CD4(-)CD8(+) lymphocytes of the PBMCs played a major role in cytokine productions following the CSFV challenge.

A randomized, open-label, comparative trial of zidovudine plus lamivudine versus zidovudine plus lamivudine plus didanosine in antiretroviral-naive HIV-1-infected Thai patients.

OBJECTIVE: To assess the efficacy and tolerability of a triple nucleoside reverse transcriptase inhibitor combination of zidovudine, lamivudine, and didanosine therapy. DESIGN: A randomized open-label trial. PATIENTS: Antiretroviral-naive HIV-infected patients with CD4+ cell counts of 100 to 500 cells/microl. METHODS: A total of 106 patients were randomly assigned to 300 mg of zidovudine (200 mg for body weight <60 kg) twice daily plus 150 mg of lamivudine twice daily plus 200 mg of didanosine (125 mg for body weight <60 kg) twice daily (n = 53) or to zidovudine plus lamivudine (n = 53) for 48 weeks. MAIN OUTCOME MEASURES: Degree and duration of reduction of HIV-1 RNA load and increase in CD4+ cell counts from baseline and development of drug-related toxicities. RESULTS: At 48 weeks, triple drug therapy showed greater declines in plasma HIV-RNA levels from the beginning of treatment than double drug therapy (1.86 vs. 1.15 log10 copies/ml, respectively; p <.001). The proportions of patients with HIV-RNA <50 copies/ml in an intention-to-treat analysis were 54.7% (29 of 53 patients) and 11.3% (6 of 53 patients) in the triple and double drug therapy, respectively (p =.001). There was no significant difference in increase of CD4 count. CONCLUSION: Triple drug therapy with zidovudine, lamivudine, and didanosine was significantly more effective in inducing sustained immunologic and virologic responses than the double combination of zidovudine and lamivudine.

A randomized, dose-finding study with didanosine plus stavudine versus didanosine alone in antiviral-naive, HIV-infected Thai patients.

OBJECTIVES: To evaluate the safety and efficacy of four different regimens of didanosine (ddI) + stavudine (d4T) in HIV-infected Thais. DESIGN: Prospective, open-label, randomized study. METHODS: Patients were randomized to four regimens of high and low doses of ddI and d4T or to ddI alone. D4T was added to the ddI-alone arm after week 24. The duration of study was 48 weeks. RESULTS: Seventy-eight patients were randomized (mean CD4 cell count, 255 x 10(6)/l; mean plasma HIV-1 RNA; 4.3 log10 copies/ml). In the intent-to-treat analysis, 78% of patients in the pooled combination arms and 20% of the patients in the ddI alone arm (to which d4T was added after 24 weeks) showed plasma HIV-1 RNA < 500 copies/ml at week 24 (P < 0.001), and 59% versus 53% at week 48, respectively. In addition, the proportion of patients with < 50 HIV-1 RNA copies/ml was 13% versus 7% at week 24 (P = 0.5) and 17% versus 20% at week 48 respectively. At week 24, median CD4 cell count increases from baseline were 101 x 10(6)/l in the pooled combination versus 76 x 10(6)/l in the ddI alone arm (P = 0.78). Logistic regression modeling suggested a correlation between receiving high dose ddI and achieving HIV-1 RNA < 500 copies/ml at week 48 (P = 0.07). CONCLUSIONS: The d4T/ddI combination was superior to ddI alone in producing HIV-1 viral suppression. At week 48, > 60% of patients treated with this combination reached HIV-1 RNA levels < 500 copies/ml. Receiving high dose ddI but not d4T may correlate with a better viral suppression.

A randomized, controlled 24-week study of intermittent subcutaneous interleukin-2 in HIV-1 infected patients in Thailand.

OBJECTIVES: To assess the immunological and virological effects, safety profile and feasibility of subcutaneous interleukin-2 (scIL-2) therapy in an HIV-infected Thai population. DESIGN: Seventy-two patients with baseline CD4 cell count of > or = 350 x 10(6)/l and no history of opportunistic infection were randomized to receive antiretroviral therapy plus scIL-2 (scIL-2 group) or antiretroviral therapy alone (control group). scIL-2 was administered at one of three doses for at least 24 weeks. The main measure of treatment efficacy was change in CD4 cell count. RESULTS: The time-weighted mean change in CD4 cell count from baseline to week 24 was + 252 x 10(6)/l for the scIL-2 group compared with + 42 x 10(6)/l for the control group (P< 0.0001). Changes in plasma HIV RNA were not significantly different between the groups over the same time period: there was a 0.83 log10 copies/ml decrease for the scIL-2 group and a 0.70 log copies/ml decrease for the control group (P= 0.362). CONCLUSIONS: This study provides the most extensive experience of scIL-2 therapy in HIV-1 infected women and Asians, and demonstrates the immunological efficacy, tolerability and feasability of scIL-2 therapy in this population. Data from this study were instrumental in guiding the selection of the scIL-2 dosing regimen for ongoing phase III trials.