Supranee Buranapraditkun

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

ObjectivesTo assess the immunological and virological effects, safety profile and feasibility of subcutaneous interleukin-2 (scIL-2) therapy in an HIV-infected Thai population. DesignSeventy-two patients with baseline CD4 cell count of ⩾ 350 × 106/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. ResultsThe time-weighted mean change in CD4 cell count from baseline to week 24 was + 252 × 106/l for the scIL-2 group compared with + 42 × 106/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). ConclusionsThis 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.

The diagnostic value of basophil activation test in patients with an immediate hypersensitivity reaction to radiocontrast media.

BACKGROUND No available test diagnoses allergic reactions to radiocontrast media (RCM). The basophil activation test (BAT) has been introduced for the diagnosis of both immunoglobulin (Ig) E and non-IgE-dependent mast cell degranulation, but its value to diagnose immediate RCM reactions is still unknown. OBJECTIVE This study aims to evaluate the diagnostic value of BAT in immediate RCM hypersensitivity. METHODS The BATs were performed in 26 patients with immediate RCM reactions and in 43 specimens from healthy volunteers. The samples whole blood was incubated with the responsible RCM and % activated (CD63+/CCR3+) basophils were analyzed by flow cytometry. Receiver operating characteristics (ROC) curve analysis was performed to calculate the optimal cutoff value of activated basophils to diagnose patients with RCM hypersensitivity. RESULTS The incubation of blood with RCM yielded significantly higher activated basophil percentages in patients with a history of immediate RCM reactions than in normal controls with both 1:100 and 1:10 dilutions (13.11% vs. 2.71%, P value = .01; and 19.23% vs. 3.73%, P = .001, respectively). Both % activated basophils and stimulation index (SI) had acceptable discrimination powers to diagnose RCM hypersensitivity. The area under the curve was 0.79 (95% CI 0.67-0.91, P = .000) by using SI as the diagnostic criteria with 1:100 dilution of RCM. The specificity of the test ranged from 88.4% to 100%. CONCLUSION Our study demonstrated the potential of BAT as a diagnostic tool for an immediate RCM hypersensitivity, particularly as a confirmation test. Further studies are required to confirm the test accuracy and identify a patients predisposing factors.

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

ObjectivesTo evaluate the safety and efficacy of four different regimens of didanosine (ddI) + stavudine (d4T) in HIV-infected Thais. DesignProspective, open-label, randomized study. MethodsPatients 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. ResultsSeventy-eight patients were randomized (mean CD4 cell count, 255 × 106/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 × 106/l in the pooled combination versus 76 × 106/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). ConclusionsThe 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.

Impaired Quality of the Hepatitis B Virus (HBV)-Specific T-Cell Response in Human Immunodeficiency Virus Type 1-HBV Coinfection

ABSTRACT Hepatits B virus (HBV)-specific T cells play a key role both in the control of HBV replication and in the pathogenesis of liver disease. Human immunodeficiency virus type 1 (HIV-1) coinfection and the presence or absence of HBV e (precore) antigen (HBeAg) significantly alter the natural history of chronic HBV infection. We examined the HBV-specific T-cell responses in treatment-naïve HBeAg-positive and HBeAg-negative HIV-1-HBV-coinfected (n = 24) and HBV-monoinfected (n = 39) Asian patients. Peripheral blood was stimulated with an overlapping peptide library for the whole HBV genome, and tumor necrosis factor alpha and gamma interferon cytokine expression in CD8+ T cells was measured by intracellular cytokine staining and flow cytometry. There was no difference in the overall magnitude of the HBV-specific T-cell responses, but the quality of the response was significantly impaired in HIV-1-HBV-coinfected patients compared with monoinfected patients. In coinfected patients, HBV-specific T cells rarely produced more than one cytokine and responded to fewer HBV proteins than in monoinfected patients. Overall, the frequency and quality of the HBV-specific T-cell responses increased with a higher CD4+ T-cell count (P = 0.018 and 0.032, respectively). There was no relationship between circulating HBV-specific T cells and liver damage as measured by activity and fibrosis scores, and the HBV-specific T-cell responses were not significantly different in patients with either HBeAg-positive or HBeAg-negative disease. The quality of the HBV-specific T-cell response is impaired in the setting of HIV-1-HBV coinfection and is related to the CD4+ T-cell count.

Optimization of a Der p 2-based prophylactic DNA vaccine against house dust mite allergy

DNA vaccines encoding allergens are promising immunotherapeutics to prevent or to treat allergy through induction of allergen-specific Th1 responses. Despite anti-allergy effects observed in small rodents, DNA-based vaccines are weak immunogens in primates and humans and particularly when administered by conventional injection. The goal of the present study was to improve the immunogenicity of a prophylactic vaccine encoding the major house dust mite allergen Der p 2. In this context, we evaluated the influence of different DNA backbones including notably intron and CpG enriched sequence, the DNA dose, the in vivo delivery by electroporation as well as the heterologous prime boost regimen on the vaccine efficiency. We found that a minimal allergen expression level threshold must be reached to induce the production of specific antibodies but beyond this limit, the intensity of the immune response was independent on the DNA dose and allergen expression. The in vivo DNA delivery by electroporation drastically enhanced the production of specific antibodies but not the IFNg secretion. Vaccination of naïve mice with DNA encoding Der p 2 delivered by electroporation even at very low dose (2μg) prevented the development of house dust mite allergy through Th1-skewed immune response characterized by the drastic reduction of allergen-specific IgE, IL-5 and lung inflammation together with the induction of strong specific IgG2a titers and IFNg secretion. CpG cassette in the DNA backbone does not play a critical role in the efficient prophylaxis. Finally, comparable protective immune responses were observed when using heterologous DNA prime/protein boost or homologous DNA prime/boost. Taken together, these data suggest that the potent Th1 response induced by DNA-based vaccine encoding allergens through electroporation provides the rationale for the evaluation of DNA encoding Der p 2 into HDM allergy clinical trials.

No Increase in Hepatitis B Virus (HBV)-Specific CD8+ T Cells in Patients with HIV-1-HBV Coinfections following HBV-Active Highly Active Antiretroviral Therapy

ABSTRACT Following treatment of hepatitis B virus (HBV) monoinfection, HBV-specific T-cell responses increase significantly; however, little is known about the recovery of HBV-specific T-cell responses following HBV-active highly active antiretroviral therapy (HAART) in HIV-HBV coinfected patients. HIV-HBV coinfected patients who were treatment naïve and initiating HBV-active HAART were recruited as part of a prospective cohort study in Thailand and followed for 48 weeks (n = 24). Production of gamma interferon (IFN-γ) and tumor necrosis factor α (TNF-α) in both HBV- and HIV-specific CD8+ T cells was quantified using intracellular cytokine staining on whole blood. Following HBV-active HAART, the median (interquartile range) log decline from week 0 to week 48 for HBV DNA was 5.8 log (range, 3.4 to 6.7) IU/ml, and for HIV RNA it was 3.1 (range, 2.9 to 3.5) log copies/ml (P < 0.001 for both). The frequency of HIV Gag-specific CD8+ T-cell responses significantly decreased (IFN-γ, P < 0.001; TNF-α, P = 0.05). In contrast, there was no significant change in the frequency (IFN-γ, P = 0.21; TNF-α, P = 0.61; and IFN-γ and TNF-α, P = 0.11) or magnitude (IFN-γ, P = 0.13; TNF-α, P = 0.13; and IFN-γ and TNF-α, P = 0.13) of HBV-specific CD8+ T-cell responses over 48 weeks of HBV-active HAART. Of the 14 individuals who were HBV e antigen (HBeAg) positive, 5/14 (36%) lost HBeAg during the 48 weeks of follow-up. HBV-specific CD8+ T cells were detected in 4/5 (80%) of patients prior to HBeAg loss. Results from this study show no sustained change in the HBV-specific CD8+ T-cell response following HBV-active HAART. These findings may have implications for the duration of treatment of HBV in HIV-HBV coinfected patients, particularly in HBeAg-positive disease.

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/μl. 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.

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.

A Novel Immunodominant CD8+ T Cell Response Restricted by a Common HLA-C Allele Targets a Conserved Region of Gag HIV-1 Clade CRF01_AE Infected Thais

Background CD8+ T cell responses play an important role in the control of HIV-1. The extensive sequence diversity of HIV-1 represents a critical hurdle to developing an effective HIV-1 vaccine, and it is likely that regional-specific vaccine strains will be required to overcome the diversity of the different HIV-1 clades distributed world-wide. Unfortunately, little is known about the CD8+ T cell responses against CRF01_AE, which is responsible for the majority of infections in Southeast Asia. Methodology/Principal Findings To identify dominant CD8+ T cell responses recognized in HIV-1 clade CRF01_AE infected subjects we drew upon data from an immunological screen of 100 HIV-1 clade CRF01_AE infected subjects using IFN-gamma ELISpot to characterize a novel immunodominant CD8+ T cell response in HIV-1 Gag restricted by HLA-Cw*0102 (p24, 277YSPVSILDI285, YI9). Over 75% of Cw*0102+ve subjects targeted this epitope, representing the strongest response in more than a third of these individuals. This novel CD8 epitope was located in a highly conserved region of HIV-1 Gag known to contain immunodominant CD8 epitopes, which are restricted by HLA-B*57 and -B*27 in clade B infection. Nonetheless, viral escape in this epitope was frequently observed in Cw*0102+ve subjects, suggestive of strong selection pressure being exerted by this common CD8+ T cell response. Conclusions/Significance As HLA-Cw*0102 is frequently expressed in the Thai population (allelic frequency of 16.8%), this immunodominant Cw*0102-restricted Gag epitope may represent an attractive candidate for vaccines specific to CRF01_AE and may help facilitate further studies of immunopathogenesis in this understudied HIV-1 clade.

Delayed differentiation of potent effector CD8+ T cells reducing viremia and reservoir seeding in acute HIV infection

Potent CD8+ T cells endowed with effector functions able to kill HIV-producing cells and reduce the seeding of the HIV reservoir are only detected at peak viremia in acute HIV infection. Peak HIV viremia pushes CD8+ T cells Aside from CD4+ T cell death, the immune system in chronically infected HIV patients is dysfunctional, including the inability of CD8+ T cells to control the virus. Animal studies with simian immunodeficiency virus have suggested that early CD8+ T cell responses may be capable of reducing viral burden, but getting access to patient samples at the earliest stage of infection is challenging. Takata et al. examined a large cohort of acutely infected patients that were given antiretroviral therapy (ART) upon enrollment in the study to evaluate T cell activation and HIV viral load over time, allowing them to parse out immune function (or dysfunction) based on acute stages of infection. They saw that CD8+ T cell responses were a little slow to ramp up but that activated CD8+ T cells present after initiation of ART could reduce the magnitude of the viral reservoir. These findings confirm that targeting CD8+ T cells at the early stage of infection could lead to viral eradication. CD8+ T cells play a critical role in controlling HIV viremia and could be important in reducing HIV-infected cells in approaches to eradicate HIV. The simian immunodeficiency virus model provided the proof of concept for a CD8+ T cell–mediated reservoir clearance but showed conflicting evidence on the role of these cells to eliminate HIV-infected cells. In humans, HIV-specific CD8+ T cell responses have not been associated with a reduction of the HIV-infected cell pool in vivo. We studied HIV-specific CD8+ T cells in the RV254 cohort of individuals initiating ART in the earliest stages of acute HIV infection (AHI). We showed that the HIV-specific CD8+ T cells generated as early as AHI stages 1 and 2 before peak viremia are delayed in expanding and acquiring effector functions but are endowed with higher memory potential. In contrast, the fully differentiated HIV-specific CD8+ T cells at peak viremia in AHI stage 3 were more prone to apoptosis but were associated with a steeper viral load decrease after ART initiation. Their capacity to persist in vivo after ART initiation correlated with a lower HIV DNA reservoir. These findings demonstrate that HIV-specific CD8+ T cell magnitude and differentiation are delayed in the earliest stages of infection. These results also demonstrate that potent HIV-specific CD8+ T cells contribute to the reduction of the pool of HIV-producing cells and the HIV reservoir seeding in vivo and provide the rationale to design interventions aiming at inducing these potent responses to cure HIV infection.