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Background and objectives: To determine the factors contributing to changes in bone mineral density (BMD) over time in HIV-infected patients receiving highly active antiretroviral therapy (HAART). Methods: Analyses of lumbar spine BMD in 183 male Caucasian participants in the Western Australian HIV Cohort study, comprising a longitudinal analysis of data from 54 patients on stable HAART regimens, and a cross-sectional analysis comparing data from 131 protease inhibitor (PI)-treated patients and 52 PI-naive (including 28 antiretroviral treatment-naive) patients. Results: Average lumbar spine BMD remained stable or increased over the time frame considered. Although there was no evidence of a change of average BMD over time in patients receiving nelfinavir (P = 0.92), there was evidence of increasing bone density in the indinavir group (average increase, 0.31 z-score per year;P < 0.001). Lower initial z-scores in the longitudinal analysis were significantly associated with lower pre-HAART BMI (P = 0.003), consistent with results of the cross-sectional analysis in which lowest BMI prior to initial dual X-ray absorptiometry scan was associated with decreased BMD (P = 0.02, overall group). Although PI therapy was also associated with decreased BMD in a univariate analysis of the cross-sectional data (P = 0.04), this effect was abrogated in a multiple linear regression analysis (P = 0.11) with lowest BMI remaining significant (P = 0.04). Conclusions: We found no evidence, overall, of accelerated bone loss in patients treated with nelfinavir- or indinavir-containing HAART regimens, and propose that indinavir therapy may be associated with an increase in bone mineral density over time. Pre-HAART BMI was an independent and powerful determinant of an individual's initial z-score in the longitudinal analysis, and adjustment for this effect in a cross-sectional analysis abrogated the association between PI therapy and decreased lumbar spine z-score.

Objective: To determine the prevalence, course and risk factors for hyperlactatemia in HIV-infected patients. Design: A prospective, longitudinal study of venous lactate concentrations over an 18-month period in 349 participants of the Western Australian HIV Cohort Study. Results: In 516 patient-years of observation, two patients experienced severe fulminant lactic acidosis (lactate > 5 mmol/l) and hepatic steatosis attributable to nucleoside analogue reverse transcriptase inhibitors (NRTI). A further five patients with lesser elevations of lactate (2.8-4.1 mmol/l) but with symptoms of nausea or abdominal discomfort and evidence of hepatic steatosis had NRTI therapy revised, with relief of symptoms and a fall in lactate levels. Most remaining patients on highly active antiretroviral therapy (HAART) had mild, chronic, asymptomatic hyperlactatemia, with mean lactate level between 1.5 mmol/l and 3.5 mmol/l most commonly. Longitudinal data was analysed in a non-linear mixed effects growth model which indicated that average lactate levels rose after the start of HAART but tended to stabilise at low-grade elevation, with an average 0.23 mmol/l greater long term level in stavudine users compared with zidovudine users (p < 0.01). A multiple linear regression model showed that the association between stavudine and higher lactate level was not confounded by longer duration of total NRTI exposure. Risk of hyperlactatemia was not significantly associated with use of other NRTIs, protease inhibitors, non-nucleoside analogue reverse transcriptase inhibitors or multiple immunological and virological factors in multivariate analyses. Conclusions: Chronic, compensated, asymptomatic hyperlactatemia is common in patients taking HAART. Decompensated, life-threatening lactic acidosis/hepatic steatosis is rare. Treatment with stavudine appears to be the predominant risk factor for development of chronic hyperlactatemia.

Background: Progressive subcutaneous fat wasting, fat accumulation, dyslipidaemia and insulin resistance in HIV-infected patients on antiretroviral therapy has been attributed to the long-term toxicity of HIV protease inhibitors (PI). More recently, fat wasting has been observed in patients who have never taken a PI, implicating an independent effect of nucleoside analogue reverse transcriptase inhibitor (NRTI) therapy. Objectives: To determine the relative contribution of NRTI and PI, as well as any other factors, to fat wasting in HIV-infected patients. Design: Longitudinal cohort study involving 277 participants of the Western Australian HIV Cohort Study. Methods: The time to onset of clinically apparent fat wasting in patients receiving different antiretroviral regimens was compared using standardized clinical criteria. Regional fat measured by dual energy X-ray absorptiometry (DEXA) in 161 patients was also compared. The average rate of percentage fat reduction was estimated in 70 patients who had consecutive DEXA scans at approximately 6-monthly intervals. Multiple confounding factors were considered in the analyses. Results: Progressive subcutaneous fat wasting, indistinguishable from that described in PI-treated patients, does occur in PI-naive, NRTI-treated patients. In patients taking triple combination antiretroviral therapy, age (relative risk = 1.052 per year;P

The efficacy of primary prophylactic treatment for opportunistic infections can be estimated in an observational cohort study by adjusting for clinical and laboratory markers of the immunodeficiency (e.g., oral candidiasis, CD4%, lymphocyte cell counts) as time-dependent co-variates (providing that the treatment does not directly alter the markers). However, the CD4 cell count provides an incomplete measure of the protective immune response, and the efficacy of treatment may be underestimated if there is inadequate adjustment for the severity of immunodeficiency. Unlike prophylactic therapies, the efficacy of which remains relatively constant over time, antiretroviral therapy may produce only transient or time-limited benefits. This problem can be minimized by allowing the effect of antiretroviral therapy to vary over time in Cox proportional hazards models (i.e., to allow the antiretroviral therapy coefficient to change over time). Another difficulty is that CD4 cell counts may underestimate the degree of immunodeficiency after prolonged zidovudine (AZT) monotherapy. If post-antiretroviral therapy CD4 cell counts are used to adjust for the stage of immunodeficiency, it may therefore be helpful to adjust for the duration of antiretroviral therapy with the CD4 cell count at the time of starting antiretroviral therapy. It is interesting to consider statistical models of progressive HIV-induced immunodeficiency in the context of the evolution of host immunity. HIV infection results in the loss of the relatively recently evolved adaptive CD4 T cell-mediated immunity to intracellular parasites. The infected host may compensate for this by making greater use of phylogenetically ancient, more innate protective responses. Because these compensatory responses are polymorphic, this results in the appearance of differences between individuals in the immune response to HIV as the disease progresses. Data from the Western Australia HIV Cohort Study support a two-stage model of immunopathology. The first stage of this model involves a loss of mucosal immunity and occurs at a variable CD4 cell count (of between 400 cells/mm3 and zero), and is marked by a loss of cutaneous delayed-type hypersensitivity responses and oral candidiasis, seborrheic dermatitis, and Pneumocystis carinii pneumonia. The second stage of the model involves a loss of systemic immunity and requires profound CD4 T-cell lymphopenia (CD4 cell count

To assess time trends in incidence of AIDS illnesses in Australia, a retrospective cohort of people diagnosed with AIDS from January 1, 1983 to December 31, 1994 in three HIV medicine units in Sydney, Melbourne, and Perth was established. Data on initial and subsequent AIDS illnesses were available for 2580 AIDS cases, or 45% of Australian AIDS notifications over the study period. Males represented 97.2% of the cohort, and HIV exposure category was homosexual contact for 89.9%. Subcohorts were formed by interval of AIDS diagnosis: 1983 through 1987, 1988 through 1990, and 1991 through 1994, with estimation of cumulative risk for each AIDS illness by the Kaplan-Meier method. The cumulative risk declined for Pneumocystis carinii pneumonia (PCP) (p < 0.0001) and for Kaposi's sarcoma (KS) (p < 0.0001); PCP cumulative risk estimates 2 years following AIDS diagnosis were 70% for people diagnosed with AIDS in 1983 through 1987 and 48% in 1991 through 1994, and KS cumulative risk estimates 2 years following AIDS diagnosis were 44% in 1983 through 1987 and 32% in 1991 through 1994. In contrast, cumulative risk increased from 34% to 40% for cytomegalovirus (CMV) disease (p = 0.005), from 47% to 50% for Mycobacterium avium complex (MAC) (p < 0.0001), and from 26% to 33% for esophageal candidiasis (p < 0.0001). Corresponding to this changing spectrum of AIDS illness has been an increase in severity of immunodeficiency at AIDS, with median CD4 cell count declining from 54 cells/mm3 in 1983 through 1987 to 34/mm3 in 1991 through 1994 (p = 0.002).

Experimental and computational evidence suggests that human leukocyte antigens (HLAs) preferentially bind conserved regions of viral proteins, a concept we term “targeting efficiency,” and that this preference can provide improved clearance of infection in several viral systems. One potential advantage of targeting conserved regions of a virus is the higher likelihood of cross-reactive protection from other viral strains, including those newly introduced, such as pH1N1. We hypothesized that individuals that targeted less conserved regions of influenza- A viruses would have weaker T-cell responses following infection with pH1N1. To test this hypothesis, T cell responses to A/H1N1 (2009) were measured from PBMCs obtained from a household cohort study performed during the 2009-2010 influenza season. We found that HLA targeting efficiency scores significantly correlated with IFNγ ELISpot responses (p=0.042, multiple regression). A further population-based analysis found that the carriage frequencies of the alleles with the lowest targeting efficiencies, A*24, were associated with pH1N1 mortality (r=0.37, p=0.031). Interestingly, these are common in certain indigenous populations in which increased pH1N1 morbidity has been reported. The computational tools utilized in this study may be useful predictors of potential morbidity and identify immunologic differences of new variant influenza strains more accurately than evolutionary sequence comparisons.

Objective: To explore trend in cumulative incidence of Kaposi's sarcoma (KS) and the level of immunodeficiency at KS diagnosis among people with AIDS in Australia. Setting: Three hospital-based HIV units. Study population: Retrospective cohort of 2580 people diagnosed with AIDS over the period 1983-1994, representing 45% of cases of AIDS in Australia over this period. Methods: Data including date and CD4 T-lymphocyte count of KS diagnosis was abstracted from medical records. KS occurring as both an initial and subsequent AIDS illness was included. Three subcohorts were defined based on interval of AIDS diagnosis: 1983-1987, 1988-1990, 1991-1994. Cumulative risk estimates for KS development were calculated by the Kaplan-Meier method. Results: KS was diagnosed in 716 people (27.8%), and in 451 (63%) of these as the initial AIDS illness. There was a decline over time in cumulative incidence of KS (P < 0.0005); the cumulative risk of KS at 1 year after AIDS diagnosis declined from 35% for those diagnosed with AIDS during 1983-1987 to 25% for 1991-1994. This decline was not due to a decline in homosexual HIV exposure category, and was independent of CD4 T-lymphocyte count at AIDS. In multivariate analysis independent risk factors for KS development were year of AIDS diagnosis (P = 0.003), male homosexuality (P = 0.003), and CD4 T-lymphocyte count at AIDS greater than 150x106/l (P = 0.02). A decline in median CD4 T-lymphocyte count at KS diagnosis was seen, from 67x106/l in 1984-1987 to 20x106/l for 1991-1994 (P < 0.0005). Conclusion: The decline in incidence and later occurrence of KS suggest several hypotheses, including declining prevalence or reduced virulence of a KS cofactor.

International audience; BACKGROUND: The health-related quality of life (HRQL) of people living with HIV infection is an important consideration in HIV management. The PROQOL-HIV psychometric instrument was recently developed internationally as a contemporary, discriminating HIV-HRQL measure incorporating influential emotional dimensions such as stigma. Here we present the first within-country results of PROQOL-HIV using qualitative and quantitative data collected from a West Australian cohort who participated in the development and validation of PROQOL-HIV, and provide a comprehensive picture of HRQL in our setting. METHODS: We carried out a secondary analysis of data from Australian patients who participated in the international study: 15 in-depth interviews were conducted and 102 HRQL surveys using the PROQOL-HIV instrument and a symptom questionnaire were administered. We employed qualitative methods to extract description from the interview data and linear regression for exploration of the composite and sub-scale scores derived from the survey. RESULTS: Interviews revealed the long-standing difficulties of living with HIV, particularly in the domains of intimate relationships, perceived stigma, and chronic ill health. The novel PROQOL-HIV instrument discriminated impact of treatment via symptomatology, pill burden and treatment duration. Patients demonstrated lower HRQL if they were: newly diagnosed (p=0.001); naive to anti-retroviral treatment (p=0.009); reporting depression, unemployment or a high frequency of adverse symptoms, (all p

Cytomegalovirus (CMV) is an increasingly important opportunistic pathogen in patients with HIV infection and advanced immune deficiency. Neurological complications due to CMV cause significant morbidity but may be treatable with specific anti-viral therapy; cerebral mass lesions are not a generally recognised manifestation. We report two patients with CMV encephalitis presenting as a cerebral mass lesion, with simultaneous occurrence of a pleuro-pulmonary mass also caused by CMV in one case, and with concurrent polyradiculomyelopathy in the other. The spectrum of previously reported clinical and radiological features of CNS involvement in AIDS is discussed. CMV should be considered in the differential diagnosis of cerebral mass lesions in patients with HIV infection and severe immune deficiency so that anti-viral therapy can be rapidly deployed.

Background: Identification of the earliest CD8 T-cell responses against HIV may help select critical viral targets for inclusion in an HIV vaccine. We describe changes to the earliest detected CD8 T-cell responses and changes in genetic sequence encoding targeted epitopes in an individual who presented with Fiebig stage II, clade C acute HIV-infection, 27 days after sexual transmission. Methods: We examined HLA-restricted CD8 T-cell responses by IFNγ ELISpot and HIV Gag, Pol, Nef and Env sequence by 454 deep sequencing over 6 timepoints, from days 27-118 after HIV-transmission. HIV-specific IFNγ responses were detected against ten HIV epitopes in Gag, Nef and Env at day 27 post HIVtransmission when the patient’s CD4 T-cell count was at a nadir of 224 cells/_l, the plasma HIV RNA >106 copies/ml and prior to any detectable p24 antibody. Results: Immunodominant responses were detected to the HLA-B*07:02 restricted Env IIRRIRQGL (IL9) epitope and the B*07:02 Gag GPGHKARVL (GL9) epitope (>4000SFU). A detectable but weaker response was observed to HLA-B*08 Nef FLKEKGGL (FL8) epitope (1010SFU). These responses declined over subsequent timepoints to 470 and 1630SFU on day 118 coincident with a 2 log fall in the plasma viral load, a rise in the CD4 T cell count to 533 cells/μL and antibody seroconversion. The Nef FL8 became the immunodominant response after day 34. IFN_ responses broadened from 10 responses at day 27 to 23 responses by day 118. Analysis of Gag, Nef and Pol genes by 454 deep sequencing showed no evidence of escape within the targeted epitopes as a cause of their decline over time. Conclusion: Early changes in the CD8 T-cell immunodominance hierarchy are apparent in acute HIV-infection prior to seroconversion, including early immunodominant targeting of Env epitopes. Subsequent broadening of the CD8 T-cell response was not associated with CD8 T-cell escape in this case.

Experimental and computational evidence suggests that human leukocyte antigens (HLAs) preferentially bind conserved regions of viral proteins, a concept we term “targeting efficiency,” and that this preference can provide improved clearance of infection in several viral systems. One potential advantage of targeting conserved regions of a virus is the higher likelihood of cross-reactive protection from other viral strains, including those newly introduced, such as pH1N1. We hypothesized that individuals that targeted less conserved regions of influenza- A viruses would have weaker T-cell responses following infection with pH1N1. To test this hypothesis, T cell responses to A/H1N1 (2009) were measured from PBMCs obtained from a household cohort study performed during the 2009-2010 influenza season. We found that HLA targeting efficiency scores significantly correlated with IFNγ ELISpot responses (p=0.042, multiple regression). A further population-based analysis found that the carriage frequencies of the alleles with the lowest targeting efficiencies, A*24, were associated with pH1N1 mortality (r=0.37, p=0.031). Interestingly, these are common in certain indigenous populations in which increased pH1N1 morbidity has been reported. The computational tools utilized in this study may be useful predictors of potential morbidity and identify immunologic differences of new variant influenza strains more accurately than evolutionary sequence comparisons.

Objective: To test the hypothesis that subclinical Mycobacterium avium intracellulare complex (MAC) infection may result in the development of a tuberculin response in immunodeficient HIV-infected individuals treated with zidovudine. Design: Longitudinal, observational study. Setting: The Western Australian HIV Cohort Study; a prospective, single centre, population-based observational study of the natural history of HIV disease. Patients: Forty-nine patients with impaired delayed-type hypersensitivity (DTH) responses and negative tuberculin responses in whom DTH responses were augmented within 6 months of starting zidovudine therapy. Outcome measures: Progression to disseminated MAC infection stratified according to the presence or absence of a tuberculin response in the first 6 months of zidovudine therapy. Results: Twenty-nine of the patients developed a post-zidovudine tuberculin response. None of the tuberculin non-responders developed disseminated MAC infection during the study period; the Kaplan-Meier probability estimate of disseminated MAC infection was 50% at 24 months and reached 100% 40 months after zidovudine was commenced in tuberculin responders. All patients with disseminated MAC infection had become anergic to all antigens, including tuberculin, before diagnosis. The probability of a post-zidovudine tuberculin response was related to the severity of peripheral blood CD4+ T-cell depletion, rising from an estimated 20% at 20% CD4+ T cells to 100% at

OBJECTIVE: To determine the incidence and nature of occupational exposures to blood and body fluids in health care workers. DESIGN: 332 reports of occupational exposure were analysed and are presented. SETTING: A major teaching hospital. PARTICIPANTS: All staff at Royal Perth Hospital who reported an occupational exposure to blood or body fluids to the Department of Clinical Immunology between 1 January 1990 and 31 August 1991. OUTCOME MEASURES: The rate of reported occupational exposure according to staff category, nature of exposure, HIV status of source patient, activity at the time of exposure and compliance with infection control measures. RESULTS: 332 reports from 323 health care workers were received, giving an overall incidence of 6.1 per 100 full time equivalent (FTE) years. Nursing staff (9.4/100 FTE years) and medical staff (9.0/100 FTE years) reported exposure more frequently than housekeeping staff (2.5/100 FTE years) or paramedical staff (2.3/100 FTE years) (P < 0.001). The rate of exposure to HIV antibody positive patients was only 0.24/100 FTE years. Needlestick or other blood contaminated sharps injuries accounted for 83.4% (277/332) of reports and failure to observe universal precautions for 34.0% of reports. Insertion and operation of parenteral lines (24%) and performing operations (15.4%) were the activities most often associated with occupational exposure. No occupationally acquired infections were observed. Despite the immediate availability of zidovudine, acceptance by health care workers with high risk occupational exposure was low (18.8%). CONCLUSIONS: Occupational exposure to blood and body fluids is common among health care workers but most exposures confer a low risk of blood borne infection. The introduction of an occupational exposure assessment program has many benefits, including optimal management of injuries and acquisition of data on infection control measures, and may protect health care institutions from false claims for compensation.

Objective: To describe a localized form of Mycobacterium avium intracellulare (MAI) infection occurring concurrently with the restoration of cutaneous delayed-type hypersensitivity (DTH) responses to mycobacterial antigens after commencement of ziclovudine therapy in immunodeficient HIV-infected patients. Patients: The first 108 Western Australian patients with a CD4+ T-cell count of =8mm and one patient who developed a positive Mantoux test to M. avium purified protein derivative developed an illness characterized by localized MAI infection, lymphadenopathy and/or severe fevers after 1-2 weeks. Conclusion: The development of localized MAI infection and/or fevers shortly after commencing ZDV in immunodeficient HIV-infected patients may reflect restoration of cellular immunity to mycobacterial antigens in some patients rather than early failure of therapy or hypersensitivity to ZDV.

Background: Despite the extensive genetic diversity of HIV-1, viral evolution in response to immune selective pressures follows broadly predictable mutational patterns. Sites and pathways of Human Leukocyte-Antigen (HLA)-associated polymorphisms in HIV-1 have been identified through the analysis of population-level data, but the full extent of immune escape pathways remains incompletely characterized. Here, in the largest analysis of HIV-1 subtype B sequences undertaken to date, we identify HLA-associated polymorphisms in the three HIV-1 proteins most commonly considered in cellular-based vaccine strategies. Results are organized into protein-wide escape maps illustrating the sites and pathways of HLA-driven viral evolution. Methodology/Principal Findings: HLA-associated polymorphisms were identified in HIV-1 Gag, Pol and Nef in a multicenter cohort of >1500 chronically subtype-B infected, treatment-naïve individuals from established cohorts in Canada, the USA and Western Australia. At q≤0.05, 282 codons commonly mutating under HLA-associated immune pressures were identified in these three proteins. The greatest density of associations was observed in Nef (where close to 40% of codons exhibited a significant HLA association), followed by Gag then Pol (where ~15–20% of codons exhibited HLA associations), confirming the extensive impact of immune selection on HIV evolution and diversity. Analysis of HIV codon covariation patterns identified over 2000 codon-codon interactions at q≤0.05, illustrating the dense and complex networks of linked escape and secondary/compensatory mutations. Conclusions/Significance: The immune escape maps and associated data are intended to serve as a user-friendly guide to the locations of common escape mutations and covarying codons in HIV-1 subtype B, and as a resource facilitating the systematic identification and classification of immune escape mutations. These resources should facilitate research in HIV epitope discovery and host-pathogen co-evolution, and are relevant to the continued search for an effective CTL-based AIDS vaccine., National Institute of Allergy and Infectious Diseases (Award Number U01AI068636 and AI068634)

NK cell receptors and HLA molecules are intimately involved in the immune response against viral infections. The killer immunoglobulin-like receptors (KIRs) on NK cells regulate NK cell responses via the recognition of their particular HLA class I ligands. At the genomic level, both genetic systems are polymorphic and have recognised haplotypes, which adds complexity to their interaction. Previously, we and others have shown the association of HLA class I with HIV progression. Recently, the Carrington group observed a synergistic effect involving the activating KIR3DS1 gene and HLA-B Bw4–80Ile on the rate of depletion of CD4+ T cells. To further investigate the relationship between the two genetic systems, we examined changes in viral load in 249 pre-treatment patients from the Western Australia HIV cohort. Genetic variants known to affect HIV progression including HLA-Bw4–80Ile but not KIR3DS1 were associated with differences in HIV-1 viral load set point. When we examined only those patients with known seroconversion dates, we found that the presence of the KIR3DS1 gene was associated with more rapid decline in the proportion of CD4+ T cells (p=0.01) but were unable to show a KIR3DS1 and Bw4–80Ile interaction. The presence of other KIR genes (viz KIR2DS2, KIR2DL2 and KIR2DS1), all found on KIR B group haplotypes, were also associated with a more rapid progression, whilst some KIR genes found the A haplotype with delayed progression We suggest that multiple KIR genes influence outcome in HIV infection. Further analyses of KIR haplotypes is needed to understand the complex interactions between KIR genes and their ligands in driving NK cell responses to HIV.

The selection in vivo of mutations in HIV-1 that allow viral escape from host HLA class I restricted cytotoxic T lymphocyte (CTL) responses has been documented in individuals. Recently we showed that the many HLA-A and -B allele-specific polymorphisms in HIV-1 reverse transcriptase (RT) suggested extensive CTLescape mutation at a population level. HLA class II restricted CD4 T helper responses have a central role in HIV-1 immunity and associations between HLA class II alleles and HIV-1 disease progression have been reported. However, CD4 T cell escape mutation in HIV-1 has not been proven. We sought to determine whether, as for CTLescape, CD4 T cell escape in HIV-1 was evident at a population level as HLA-DRB1 associated polymorphisms. We analysed the diversity of HIV-1 RT sequences in a large, well characterised cohort of HIV-1 infected patients over 2210 person-years of observation. We examined the relationship between the HLA-A, -B and -DRB1 alleles present in the cohort (as covariates) and polymorphism in HIV-1 RT (as the outcome) in multivariate logistic regression models. Each single residue in HIV-1 RT (positions 20-227) was examined in separate models sequentially. Power calculations and model selection steps were carried out to limit the number of comparisons, and final Bonferroni correction was made to mark out the most significant associations. Polymorphism in HIV-1 RT occurred at sites with least functional constraint against mutation. At these sites, we identified 64 characteristic polymorphisms associated with specific HLA-A or -B alleles (OR > 1, p 1, p < 0.05). Four of the 5 known T helper cell epitopes in HIV-1 RT encompassed sites of HLA-DRB1 allele-specific polymorphism found in our study. There were also 'negative associations' between polymorphism and common HLA alleles, suggesting that the HIV-1 consensus sequence could have been selected by the host population's dominant HLA. This novel, population-based approach shows that polymorphisms in HIV-1 sequence are characteristic for specific HLA class I and II alleles, in keeping with viral adaptation to both the CTLand CD4 T helper cell responses of a human host population. These findings suggest that HLA has a central role in HIV-1 primordial and contemporary evolution and has implications for epitope mapping and predicting HIV-1 dynamics in individuals.

OBJECTIVE To determine the incidence of and reasons for late presentation of patients infected with the human immunodeficiency virus (HIV), and the demographic characteristics of these late presenters, who first seek medical attention when they have an illness that defines the acquired immunodeficiency syndrome (AIDS). DESIGN Retrospective analysis of clinical and demographic data relating to 106 sequential AIDS diagnoses in Western Australia. Surviving patients were questioned during routine medical and social work interviews to identify the reasons for late presentation. SETTING Royal Perth Hospital, the sole specialist referral centre for the management of infection with the human immunodeficiency virus (HIV) in Western Australia. PARTICIPANTS All patients presenting or referred to Royal Perth Hospital with an AIDS-defining condition between 1 January 1988 and 1 July 1991. RESULTS Forty-one of 106 (39%) patients presenting with an AIDS-defining condition had known of their HIV status for eight weeks or less (late presenters). The proportion of late presenters decreased from 61% in 1988 to 34% in 1989 (P less than 0.05). Six of the 41 late presenters died during their initial admission compared with only one of the 65 early presenters (P less than 0.02). Sixty-six per cent of late presenters compared with only 35% of early presenters had pneumocystis pneumonia as their AIDS-defining condition (P less than 0.01). There was no significant difference in age at diagnosis of AIDS, martial status, sex or risk factors between the early and late presentation groups. Reasons given for late presentation included lack of knowledge of advances in the treatment of HIV infection, concerns about confidentiality and beliefs that sexual behaviour had been relatively "safe" from risk of HIV infection. CONCLUSIONS While the proportion of patients presenting late is decreasing, late presentation continues to be a problem. Reasons for delayed presentation are not entirely clear, but can be explained in terms of psychosocial and physiological influences. How and to what degree each of these contribute to timing of presentation is yet to be determined.

Contemporary survival analytic praxis affords several methods for both appraising and extending the Cox proportional hazards model. With regard assessment a variety of diagnostic plots based on martin-gale and related residuals are available. One extension, additive proportional hazards models, allows sums of univariate smooth functions of the covariates as a generalization of the Cox model linear predictor. A complementary method, tree-structured survival analysis, is adept at identifying homogenous subgroups having distinct survival patterns. We apply this array of techniques to an evaluation of markers of HIV disease progression. Issues concerning survival analysis from seroprevalent cohort data are described. Little used measures of partial dependence for censored data are invoked in this context. Results from the Western Australian HIV Cohort Study indicate that delayed-type hypersensitivity skin tests augment CD4 cell counts in predicting time-to-AIDS and time-to-death.

During the 24-week PIILR study of protease inhibitor (PI) withdrawal, improved lipids and reduction in intraabdominal visceral fat was seen, however, there was also a loss of subcutaneous limb fat in patients with HIV-lipodystrophy (LD). It was hypothesized that overall improvement in LD may require a longer period of time off PIs.Follow-up of patients randomized to stop or continue PI-based therapy for 24 weeks, in a multicenter study, was continued for up to 120 weeks. Biochemistry and lipid parameters were assessed every 3 months. DEXA and CT scans were performed annually. Limb fat, visceral adipose tissue, and the lipodystrophy case definition score (LCDS) were used as indicators of LD severity.Forty-five male patients with baseline and week 120 body composition data were assessed. There were no significant changes in the limb fat or visceral adipose tissue (VAT) components of LD, with the exception of the LCDS (change from baseline +5.79, p.001). Control of viral replication was maintained and lipid and glycemic parameters were unchanged over the 120-week follow-up. Linear regression analysis showed on-study usage of stavudine was independently and significantly correlated with both decreased limb fat mass and a higher LCDS.Body composition or metabolic features of LD did not improve over 2 years of observation in patients remaining on predominantly PI-sparing therapy. LD was adversely influenced by continued stavudine use.

‘Lipodystrophy syndrome’ in the setting of HIV infection has come to encompass a collection of morphological and metabolic abnormalities linked with the use of antiretroviral therapy and other risk factors. We review the clinical literature on this subject as it has evolved historically, taking pertinent methodological issues into account.

Background Massive, parallel sequencing is a potent tool for dissecting the regulation of biological processes by revealing the dynamics of the cellular RNA profile under different conditions. Similarly, massive, parallel sequencing can be used to reveal the complexity of viral quasispecies that are often found in the RNA virus infected host. However, the production of cDNA libraries for next-generation sequencing (NGS) necessitates the reverse transcription of RNA into cDNA and the amplification of the cDNA template using PCR, which may introduce artefact in the form of phantom nucleic acids species that can bias the composition and interpretation of original RNA profiles. Method Using HIV as a model we have characterised the major sources of error during the conversion of viral RNA to cDNA, namely excess RNA template and the RNaseH activity of the polymerase enzyme, reverse transcriptase. In addition we have analysed the effect of PCR cycle on detection of recombinants and assessed the contribution of transfection of highly similar plasmid DNA to the formation of recombinant species during the production of our control viruses. Results We have identified RNA template concentrations, RNaseH activity of reverse transcriptase, and PCR conditions as key parameters that must be carefully optimised to minimise chimeric artefacts. Conclusions Using our optimised RT-PCR conditions, in combination with our modified PCR amplification procedure, we have developed a reliable technique for accurate determination of RNA species using NGS technology.

Table of contents Poster walk 11: miscellaneous drug hypersensitivity 2 (P92–P94, P96–P101) P92 16 years of experience with proton pump inhibitors (PPIs) Javier Dionicio Elera, Cosmin Boteanu, Maria Aranzazu Jimenez Blanco, Rosario Gonzalez-Mendiola, Irene Carrasco García, Antonio Alvarez, Jose Julio Laguna Martinez P93 Allergy evaluation of quinolone induced adverse reactions Jaume Martí Garrido, Carla Torán Barona, Carolina Perales Chorda, Ramón López Salgueiro, Miguel Díaz Palacios, Dolores Hernández Fernández De Rojas P94 Bupropion-induced acute urticaria and angioedema, a case report Emre Ali Acar, Ayse Aktas, Aylin Türel Ermertcan, Peyker Temiz P96 Delayed type hypersensitivity and study of cross-reactivity between proton-pump inhibitors Chien-Yio Lin, Chung-Yee Rosaline Hui, Ya-Ching Chang, Chih-Hsun Yang, Wen-Hung Chung P97 Diagnostic work-up in suspected hypersensitivity to proton-pump inhibitors: looking at cross-reactivity Fabrícia Carolino, Diana Silva, Eunice Dias De Castro, Josefina R. Cernadas P98 Management of infusion-related hypersensitivity reactions to enzyme replacement therapy for lysosomal diseases Luis Felipe Ensina, Carolina Aranda, Ines Camelo Nunes, Alex Lacerda, Ana Maria Martins, Ekaterini Goudouris, Marcia Ribeiro, José Francisco Da Silva Franco, Leandra Queiroz, Dirceu Solé P99 Management of insulin allergy with continuous subcutaneous insulin infusion Ceyda Tunakan Dalgiç, Aytül Zerrin Sin, Fatma Düsünür Günsen, Gökten Bulut, Fatma Ömür Ardeniz, Okan Gülbahar, Emine Nihal Mete Gökmen, Ali Kokuludag P100 Off-label use of icatibant for management of serious angioedema associated with angiotensin inhibitors Ana M. Montoro De Francisco, Talía Mª De Vicente Jiménez, Adriana M. Mendoza Parra, Angella M. Burgos Pimentel, Amelia García Luque P101 Thiocolchicoside anaphylaxis: an unusual suspect? Luis Amaral, Fabricia Carolino, Leonor Carneiro Leão, Eunice Castro, Josefina Cernadas Poster walk 12: betalactam hypersensitivity (P102–P111) P102 A curious delayed reading: a case report of a β-lactam allergy in a child Nicole Pinto, Joana Belo, João Marques, Pedro Carreiro-Martins, Paula Leiria-Pinto P103 Betalactam-induced hypersensitivity: a 10-years’ experience Amel Chaabane, Haifa Ben Romdhane, Nadia Ben Fredj, Zohra Chadly, Naceur A. Boughattas, Karim Aouam P104 Cefazolin hypersensitivity: towards optimized diagnosis Astrid P. Uyttebroek, Chris H. Bridts, Antonino Romano, Didier G. Ebo, Vito Sabato P105 Clavulanic acid allergy: two cases report Anabela Lopes, Joana Cosme, Rita Aguiar, Tatiana Lourenço, Maria-João Paes, Amélia Spínola-Santos, Manuel Pereira-Barbosa P106 Diagnosis of betalactam allergy in an allergy department Cíntia Rito Cruz, Rute Pereira Dos Reis, Elza Tomaz, Ana Paula Pires, Filipe Inácio P107 Diagnostic work-up of 410 patients with suspicion of betalactam antibiotic hypersensitivity Filipe Benito-Garcia, Inês Mota, Magna Correia, Ângela Gaspar, Marta Chambel, Susana Piedade, Mário Morais-Almeida P108 Immediate selective hypersensitivity reactions to clavulanic acid Alla Nakonechna, Yurij Antipkin, Tetiana Umanets, Fernando Pineda, Francisca Arribas, Volodymyr Lapshyn P109 Prevalence and incidence of penicillin hypersensitivity reactions in Colombia Pablo Andrés Miranda, Bautista De La Cruz Hoyos P110 Selective sensitization to amoxicilin and clavulanic acid Jose Julio Laguna Martinez, Aranzazu Jimenez Blanco, Javier Dionicio Elera, Cosmin Boteanu, Rosario Gonzalez-Mendiola, Marta Del Pozo P111 Infliximab-specific T cells are detectable also in treated patients who have not developed anti-drug antibodies Alessandra Vultaggio, Francesca Nencini, Sara Pratesi, Andrea Matucci, Enrico Maggi Poster walk 13: biologicals, local anesthetics, others (P112–P118) P112 A case report of allergic immediate systemic reaction to adalimumab and certolizumab Ceyda Tunakan Dalgiç, Fatma Düsünür Günsen, Gökten Bulut, Fatma Ömür Ardeniz, Okan Gülbahar, Emine Nihal Mete Gökmen, Aytül Zerrin Sin, Ali Kokuludag P113 Allergy to local anesthetics: negative predictive value of skin tests Ivana Cegec, Danica Juricic Nahal, Viktorija Erdeljic Turk, Matea Radacic Aumiler, Ksenija Makar Ausperger, Iva Kraljickovic, Iveta Simic P114 Cutaneous adverse reactions of molecular targeted agents: a retrospective analysis in 150 patients in our department Yukie Yamaguchi, Tomoya Watanabe, Megumi Satoh, Tomohiko Tanegashima, Kayoko Oda, Hidefumi Wada, Michiko Aihara P115 Generalized paralysis induced by local lidocaine injection Jaechun Jason Lee, Jay Chol Choi, Hwa Young Lee P116 Hypersensitivity to local anaesthetics: a 10 year review Rosa-Anita Rodrigues Fernandes, Emília Faria, Joana Pita, Nuno Sousa, Carmelita Ribeiro, Isabel Carrapatoso, Ana Todo Bom P117 Local anaesthetics: a rare culprit in hypersensitivity reactions Ana Rodolfo, Eunice Dias-Castro, Josefina Cernadas P118 Stevens–Johnson syndrome in clinical practice: a variant of clinical course Marina Voronova Poster walk 14: RCM (P119–P128) P119 13 cases of severe anaphylactic reactions due to radiocontrast media Jaume Martí Garrido, Ramon Lopez Salgueiro, Diana Kury Valle, Verónica Pacheco Coronel, Carolina Perales Chordá, Dolores Hernandez Fernandez De Rojas P120 Anaphylactic shock after administration of iodinated contrast medium during cardiac catheterization Roselle Catherine Yu Madamba, Marta Ferrer, Maria Jose Goikoetxea, Carmen D’Amelio, Amalia Bernad, Olga Vega, Gabriel Gastaminza P121 Anaphylactic shock and cardiac arrest induced by gadolinium-based contrast agents Beatriz Pola Bibián, Marina Lluncor Salazar, Gemma Vilà Nadal, Ana María Fiandor Roman, Javier Dominguez Ortega, Miguel Gonzalez Muñoz, Santiago Quirce Gancedo, Maria Rosario Cabañas Moreno P122 Anaphylaxis to gadobenate and cross-reactivity to other gadolinium-based contrast agents in two patients Kathrin Scherer Hofmeier P123 Anaphylaxis to glatiramer acetate in a patient with multiple sclerosis Fabrícia Carolino, Vladyslava Barzylovych, Josefina R. Cernadas P124 Delayed hypersensitivity reaction to radiocontrast media Fabrícia Carolino, Diana Silva, Leonor Leão, Josefina R. Cernadas P125 Drug reaction with eosinophilia and systemic symptoms induced by iodixanol Gemma Vilà-Nadal, Beatriz Pola, Marina Lluncor, Ana Fiandor, Teresa Bellón, Javier Domínguez, Santiago Quirce P126 Electronic consultation support system for radiocontrast media hypersensitivity changes clinician’s behavior Min-Suk Yang, Sun-Sin Kim, Sae-Hoon Kim, Hye-Ryun Kang, Heung-Woo Park, Sang-Heon Cho, Kyung-Up Min, Yoon-Seok Chang P127 Hypersensitivity reactions to iodinated contrast media: skin testing and follow-up Danica Juricic Nahal, Ivana Cegec, Viktorija Erdeljic Turk, Iva Kraljickovic, Matea Radacic Aumiler, Ksenija Makar Ausperger, Iveta Simic P128 Would iodine allergy exist? Clémence Delahaye, Jenny Flabbee, Julie Waton, Olivia Bauvin, Annick Barbaud Poster walk 15: MPE/type 4 (P129–P137) P129 Delayed hypersensitivity cutaneous reactions: a case/control study from a tunisian database Karim Aouam, Najah Ben Fadhel, Zohra Chadly, Nadia Ben Fredj, Naceur A. Boughattas, Amel Chaabane P130 Delayed hypersensitivity reactions to cephalosporins: a review of seven cases Joana Cosme, Anabela Lopes, Amélia Spínola-Santos, Manuel Pereira-Barbosa P131 Diclofenac induced allergic contact dermatitis: case series of four patients Sandra Jerkovic Gulin, Anca Chiriac P132 Late-onset maculopapular rash to irbesartan Bárbara Kong Cardoso, Elza Tomaz, Regina Viseu, Filipe Inácio P133 Nonimmediate hypersensitivity reactions to betalactams: a retrospective analysis Ana Moreira, Susana Cadinha, Ana Castro Neves, Patricia Barreira, Daniela Malheiro, J. P. Moreira Da Silva P134 Occupational airborne contact dermatitis to omeprazole Ružica Jurakic-Toncic, Suzana Ljubojevic, Petra Turcic P135 Ornidazole-induced fixed drug eruption confirmed by positive patch test on a residual pigmented lesion Liesbeth Gilissen, Sara Huygens, An Goossens P136 Repeated delayed reaction induced by amoxicillin and amoxicillin clavulanate Inmaculada Andreu, Ramon Lopez-Salgueiro, Alicia Martinez Romero, Pau Gomez Cabezas P137 Systemic photosensitivity from fenofibrate in a patient photo-sensitized to ketoprofen Liesbeth Gilissen, An Goossens Poster walk 16: HLA genetics (P138–P146) P138 A copy number variation in ALOX5 and PTGER1 is associated with nonsteroidal anti-inflammatory drugs induced urticaria and/or angioedema Pedro Ayuso Parejo, Maria Del Carmen Plaza-Serón, Inmaculada Doña, Natalia Blanca López, Carlos Flores, Luisa Galindo, Ana Molina, James Richard Perkins, Jose Antonio Cornejo-García, José Augusto García-Agúndez, Elena García-Martín, Paloma Campo, María Gabriela Canto, Miguel Blanca P139 Association of galectin-3 (LGALS3) single nucleotide polymorphisms with non-steroidal anti-inflammatory drugs-induced urticaria/angioedema José Antonio Cornejo-Garcia, Inmaculada Doña, Rosa María Guéant-Rodríguez, Natalia Blanca-López, María Carmen Plaza-Serón, Raquel Jurado-Escobar, Esther Barrionuevo, María Salas, María Luisa Galindo, Gabriela Canto, Miguel Blanca, Jean-Louis Guéant P140 Detection of T cell responses to ticlopidine using peripheral blood mononuclear cells from HLA-A*33:03+ healthy donors Toru Usui, Arun Tailor, Lee Faulkner, John Farrell, Ana Alfirevic, B. Kevin Park, Dean J. Naisbitt P141 Epistasis approaches to identify novel genes potentially involved in NSAIDs hypersensitivity James Richard Perkins, Jose Antonio Cornejo García, Oswaldo Trelles, Inmaculada Doña, Esther Barrionuevo, María Salas, María Auxiliadora Guerrero, Miguel Blanca, Alex Upton P142 Genetic predisposition of cold medicine related SJS/TEN with severe ocular complications Mayumi Ueta, Hiromi Sawai, Chie Sotozono, Katushi Tokunaga, Shigeru Kinoshita P143 HLA-B*13:01 and dapsone induced hypersensitivity in Thai population Chonlaphat Chonlaphat Sukasem, Patompong Satapornpong, Therdpong Tempark, Pawinee Rerknimitr, Kulprapat Pairayayutakul, Jettanong Klaewsongkram P144 HLA-B*15:02 alleles and lamotrigine-induced cutaneous adverse drug reactions in Thai Chonlaphat Sukasem, N. Koomdee, T. Jantararoungtong, S. Santon, A. Puangpetch, U. Intusoma, W. Tassaneeyakul, V. Theeramoke P145 HLA-B*38:01 and HLA-A*24:02 allele frequencies in Spanish patients with lamotrigine-induced SCARs Teresa Bellón, Elena Ramirez, Alberto Manuel Borobia, Hoi Tong, Jose Luis Castañer, Francisco José De Abajo P146 Overrepresentation of a class II HLA haplotype in severe hypersensitivity type I reactions to carboplatin Violeta Régnier Galvao, Rebecca Pavlos, Elizabeth Mckinnon, Kristina Williams, Alicia Beeghly-Fadiel, Alec Redwood, Elizabeth Phillips, Mariana Castells Poster walk 17: in vivo diagnosis + sIgE (P147–P154) P147 Absence of specific Ig-e against beta-lactams 9 months after an allergic reaction to amoxicillin-clavulanic acid Elisa Boni, Marina Russello, Marina Mauro P148 Drug provocation tests in suspected opioid allergy Kok Loong Ue, Krzysztof Rutkowski P149 Improvement to the specific IgE cut-off in the assess of β-lactamic allergy Victor Soriano Gomis, Jorge Frances Ferre, Angel Esteban Rodriguez, Vicente Cantó Reig, Javier Fernandez Sanchez P150 Initial false negative specific IgE to gelatin in a patient with gelatin-induced anaphylaxis Christine Breynaert, Erna Van Hoeyveld, Rik Schrijvers P151 Inmediate reactions to beta-lactam antibiotics: pattern of skin test response over the time Jose Julio Laguna Martinez, Rosario Gonzalez Mendiola, Javier Dionicio Elera, Cosmin Boteanu, Aranzazu Jimenez Blanco, Marta Del Pozo, Raquel Fuentes Irigoyen P152 New fluorescent dendrimeric antigens for the evaluation of dendritic cell maturation as a test to detect allergy reactions to amoxicillin Daniel Collado, Yolanda Vida, Francisco Najera, Ezequiel Perez-Inestrosa, Pablo Mesa-Antunez, Cristobalina Mayorga, María José Torres, Miguel Blanca P153 Positive skin test or positive specific IgE to penicillin does not predict penicillin allergy Line K. Tannert, Charlotte G. Mortz, Per Stahl Skov, Carsten Bindslev-Jensen P154 Significance of skin testing and in vitro-analysis of neuromuscular blocking agents in diagnosis of perioperative drug hypersensitivity: evaluation of a negative control population Wolfgang Pfützner, Hannah Dörnbach, Johanna Visse, Michele Rauber, Christian Möbs Poster walk 18: in vitro/ex vivo (P155–P158, P160–P164) P155 Diagnostic value of the lymphocyte toxicity assay (LTA) and the in vitro platelet toxicity assay (IPTA) for β-lactam allergy Abdelbaset A. Elzagallaai, Lindsey Chow, Awatif M. Abuzgaia, Michael J. Rieder P156 Enzyme linked immunospot assay used in the diagnosis of severe cutaneous adverse reactions to antimicrobials Alec Redwood, Jason Trubiano, Rebecca Pavlos, Emily Woolnough, Kaija Stautins, Christina Cheng, Elizabeth Phillips P157 Evaluation of in vitro diagnostic methods for identifying the culprit drugs in drug hypersensitivity Kenichi Kato, Hiroaki Azukizawa, Takaaki Hanafusa, Ichiro Katayama P158 Ex-vivo expanded skin-infiltrating T cells from severe drug eruptions are reactive with causative drugs: a possible novel method for determination of causative drugs Toshiharu Fujiyama, Hideo Hashizume, Takatsune Umayahara, Taisuke Ito, Yoshiki Tokura P160 In vitro release of IL-2, IL-5 and IL-13 in diagnosis of patients with delayed-type nickel hypersensitivity Mira Silar, Mihaela Zidarn, Helena Rupnik, Peter Korosec P161 Single cell analysis of drug responsive T cells; identification of candidate drug reactive T cell receptors in abacavir and carbamazepine hypersensitivity Alec James Redwood, Kaija Strautins, Katie White, Abha Chopra, Katherine Konvinse, Shay Leary, Rebecca Pavlos, Simon Mallal, Elizabeth Phillips P162 Specificity and sensitivity of LTT in DRESS: analysis of agreement with the Spanish pharmacovigilance system probability algorithm Rosario Cabañas, Elena Ramirez, Ana María Fiandor, Teresa Bellón P163 The role of interleukin-22 in β-lactam hypersensitivity Andrew Sullivan, Paul Whitaker, Daniel Peckham, B. Kevin Park, Dean J. Naisbitt P164 Vancomycin-specific T cell responses and teicoplanin cross-reactivity Wei Yann Haw, Marta E. Polak, Carolann Mcguire, Michael R. Ardern-Jones Poster walk 19: BAT and biomarkers (P165–P173) P165 A combination of early biomarkers useful for the prediction of severe ADRs Yumi Aoyama, Tetsuo Shiohara P166 Basophil activation test in the diagnostic approach of reactions during general anaesthesia Ana Moreira, Susana Cadinha, Patrícia Barreira, Ana Castro Neves, Daniela Malheiro, Sara Correia, J. P. Moreira Da Silva P167 IL-10 can be related to successful desensitization Asli Gelincik, Semra Demir, Fatma Sen, Hamza Ugur Bozbey, Muge Olgac, Derya Unal, Raif Coskun, Bahauddin Colakoglu, Suna Buyuozturk, Esin Çatin-Aktas, Gunnur Deniz P168 Immediate reactions to proton pump inhibitors: value of basophil activation test Maria Salas, Jose Julio Laguna, Esther Barrionuevo, J. Dionicio, Tahia Fernandez, R. Gonzalez-Mendiola, I. Olazabal, Maria Dolores Ruiz, Miguel Blanca, Cristobalina Mayorga, Maria José Torres P169 Improvement of the elevated tryptase criterion to discriminate IgE from non-IgE mediated allergic reactions Gabriel Gastaminza, Alberto Lafuente, Carmen D’Amelio, Amalia Bernad, Olga Vega, Roselle Catherine Madamba, M. Jose Goikoetxea, Marta Ferrer, Jorge Núñez P170 Low expression of Tim-3 could serve as a biomarker for control and diagnose maculopapular exanthema induced by drugs Tahia Diana Fernández, Inmaculada Doña, Francisca Palomares, Rubén Fernández, Maria Salas, Esther Barrionuevo, Maria Isabel Sanchez, Miguel Blanca, Maria José Torres, Cristobalina Mayorga P171 Role of basophil activation test using two different activation markers for the diagnosis of allergy to fluoroquinolones Esther Barrionuevo, Tahía Fernandez, Arturo Ruiz, Adriana Ariza, Maria Salas, Inmaculada Doña, Ana Molina, Miguel Blanca, Maria Jose Torres, Cristobalina Mayorga P172 The importance of basophil activation test in anaphylaxis due to celecoxib Amalia Bernad Alonso, Carmen D’Amelio Garófalo, Olga Vega Matute, Marta Ferrer Puga, María José Goikoetxea Lapresa, Roselle Catherine Yu Madamba, Gabriel Gastaminza Lasarte P173 The role of basophil activation test in the diagnosis of immediate type drug hypersensitivity to betalactam antibiotics Antonia Thinnes, Hans F. Merk, Jens Malte Baron, Martin Leverkus, Galina Balakirski Poster walk 20: TCR recognition, cellular (P174–P183) P174 Characterisation of the effect of co-inhibitory signalling on the activation of drug-derived antigen-specific T-cells Andrew Gibson, Monday Ogese, Lee Faulkner, B. Kevin Park, Dean J. Naisbitt P175 Characterization of drug hapten-specific T cell responses in piperacillin hypersensitive patients Zaid Al-Attar, Fiazia Yaseen, Xiaoli Meng, Rozalind Jenkins, Paul Whitaker, Daniel Peckham, Lee Faulkner, John Farrel, Kevin Park, Dean Naisbitt P176 Characterization of the response of T-cells to telaprevir and its metabolite in normal volunteers Zaid Al-Attar, Khetam Alhilali, Yanni Xue, John Farrell, Lee Faulkner, Kevin Park, Dean Naisbitt P177 Characterization of the T cell receptor signatures of drug-responsive T cells Patricia Illing, Nicole Mifsud, Heidi Fettke, Jeffrey Lai, Rebecca Ho, Patrick Kwan, Anthony Purcell P178 Defining the signals between hepatocytes and immune cells in idiosyncratic drug-induced liver injury (DILI) Monday O. Ogese, Lee Faulkner, B. Kevin Park, Catherine Betts, Dean J. Naisbitt P179 Development of novel chemicals that do not bind to HLA-B*57:01 or activate CD8 + T-cells through modification of the 6-amino cyclopropyl group of abacavir Paul Thomson, John Farrell, Mohammad Alhaidari, Neill Berry, Paul M. O’Neill, B. Kevin Park, Dean J. Naisbitt P180 Generation and characterization of dapsone- and nitroso-dapsone-specific T-cell clones using lymphocytes from healthy volunteers Abdulaziz Alzahrani, Monday O. Ogese, John Farrell, Lee Faulkner, Andrew Gibson, Arun Tailor, B. Kevin Park, Dean J. Naisbitt P181 Identification of benzylpenicillin-hapten peptides responsible for naïve T-cell activation and immunization of allergic patients to penicillin Marie Eliane Azoury, Lucia Fili, Rami Bechara, Noémie Scornet, Cathy Nhim, Richard Weaver, Nancy Claude, Delphine Joseph, Bernard Maillere, Paola Parronchi, Marc Pallardy P182 Massive expansion of clonotypic and polycytotoxic CD8+ T cells in toxic epidermal necrolysis Axel Patrice Villani, Aurore Rozières, Benoît Bensaïd, Mathilde Tardieu, Floriane Albert, Virginie Mutez, Tugba Baysal, Marc Pallardy, Janet Maryanski, Jean-François Nicolas, Osami Kanagawa, Marc Vocanson P183 Pharmaco-immunological synapse of HLA-drug-TCR in SCAR Shuen-Iu Hung Poster walk 21: new in vitro methods, haptens, etc. (P184–P194) P184 Amoxicillin-clavulanate forms distinct multiple haptenic structures on human serum albumin in patients Xiaoli Meng, Arun Tailor, Caroline J. Harrison, Rosalind E. Jenkins, Paul Whitaker, Neil S. French, Dean J. Naisbitt, B. Kevin Park P185 Dendrimeric antigens for studying the influence of penicillin determinants orientation on IgE recognition Maria Isabel Montañez, Cristobalina Mayorga, Francisco Najera, Adriana Ariza, Tahia D. Fernandez, Maria Salas, Angela Martin-Serrano, Miguel Blanca, Ezequiel Perez-Inestrosa, Maria Jose Torres P186 Dendrimeric antigens on solid supports: designed materials for IgE quantification Yolanda Vida, Maria Isabel Montañez, Noemi Molina, Daniel Collado, Francisco Najera, Adriana Ariza, Maria Jose Torres, Cristobalina Mayorga, Ezequiel Perez-Inestrosa P187 Development of a screening assay for drug hypersensitivity using naïve T cells from donors with seven different HLA class I risk alleles Lee Faulkner, Sally Wood, Ana Alfirevic, Munir Pirmohamed, Dean J. Naisbitt, B. Kevin Park P188 Different patterns of recognition of structures derived from amoxicillin by IgE antibodies from patients with immediate hypersensitivity reactions to betalactams Adriana Ariza, Cristobalina Mayorga, María Isabel Montañez, María Salas, Inmaculada Doña, Ángela Martín-Serrano, Ezequiel Pérez-Inestrosa, Dolores Pérez-Sala, Miguel Blanca, Antonio E. Guzmán, María José Torres P189 High-resolution typing of HLA polymorphism and T-cell receptor repertoire for severe adverse drug reactions based on the cost-effective next-generation sequencing approaches Tai-Ming Ko, Yuan-Tsong Chen, Jer-Yuarn Wu P190 Identification and fate of intracellular proteins haptenated by amoxicillin Francisco J. Sánchez-Gómez, Juan M. González-Morena, Yolanda Vida, Ezequiel Pérez-Inestrosa, Miguel Blanca, María J. Torres, Dolores Pérez-Sala P191 In vitro detection of terbinafine protein adducts Arun Tailor, Toru Usui, Yanni Xue, Xiaoli Meng, Dean J. Naisbitt, B. Kevin Park P192 MicroRNAs dysregulation in PBMCs from drug hypersensitivity patients during drug challenge in vitro Alejandra Monroy Arreola, Jesus Agustin Badillo Corona, Silvia Mendez Flores, Judith Dominguez Cherit, Dean J. Naisbitt, Noe Valentin Duran Figueroa, Jose Luis Castrejon Flores P193 NSAIDs-exacerbated cutaneous disease: high throughput gene expression profiling José Antonio Cornejo-García, James Perkins, Natalia Blanca-López, Diana Pérez-Alzate, Raquel Jurado-Escobar, Inmaculada Doña, Gador Bogas, María J. Torres, Gabriela Canto, Miguel Blanca P194 Utility of skin tests in non-immediate reactions to amoxicillin Luis Mario Tubella Marti, Fernando Pineda De La Losa, Francisca Arribas Poves, Jaime Tubella Lopez, Teodora Lopez Santiago

Immunodominance is variably used to describe either the most frequently detectable response among tested individuals or the strongest response within a single individual, yet factors determining either inter- or intraindividual immunodominance are still poorly understood. More than 90 individuals were tested against 184 HIV- and 92 EBV-derived, previously defined CTL epitopes. The data show that HLA-B-restricted epitopes were significantly more frequently recognized than HLA-A- or HLA-C-restricted epitopes. HLA-B-restricted epitopes also induced responses of higher magnitude than did either HLA-A- or HLA-C-restricted epitopes, although this comparison only reached statistical significance for EBV epitopes. For both viruses, the magnitude and frequency of recognition were correlated with each other, but not with the epitope binding affinity to the restricting HLA allele. The presence or absence of HIV coinfection did not impact EBV epitope immunodominance patterns significantly. Peptide titration studies showed that the magnitude of responses was associated with high functional avidity, requiring low concentration of cognate peptide to respond in in vitro assays. The data support the important role of HLA-B alleles in antiviral immunity and afford a better understanding of the factors contributing to inter- and intraindividual immunodominance.

Clinical research has indicated that the use of nucleoside reverse transcriptase inhibitor (NRTI) and HIV protease inhibitor (PI) therapy is associated with a risk of long-term toxicity syndromes, and that the aetiopathogenesis of these adverse effects is independent of the antiretroviral effects of these drugs. In relation to the lipodystrophy syndrome, it appears that the most powerful determinant of subcutaneous fat wasting is an interaction between these two drug classes. In this review, possible mechanisms underlying the contributions of both PI and NRTI drugs are reviewed, with an emphasis on their effects on adipose tissue. On this basis, an ‘adipocentric’, or minimal model of the syndrome is developed, in which divergent effects at the adipocyte of NRTIs (mitochondrial toxicity) and PIs (insulin resistance and impaired adipocyte maturation) interact to produce a phenotype that is consistent with clinical observations.

This preliminary report describes a new method of treating bilateral cryptorchidism that may modify the need for surgical intervention. Four of five boys (3 1/2, 3 1/2, 7, 11 and 12 1/2 years of age) given hourly subcutaneous pulses of luteinizing hormone-releasing hormone (LH-RH, 10 to 100 micrograms/day, given in a 3-min pulse every hour) showed evidence of testicular descent after 3 to 19 weeks. The battery-operated, programmable syringe driver was well tolerated by the boys, and the daily insertion of the scalp-vein needles was managed at home by their parents.

SummaryThe basis for strong immunogenetic associations between particular human leukocyte antigen (HLA) class I allotypes and inflammatory conditions like Behçet's disease (HLA-B51) and ankylosing spondylitis (HLA-B27) remain mysterious. Recently, however, even stronger HLA associations are reported in drug hypersensitivities to the reverse-transcriptase inhibitor abacavir (HLA-B57), the gout prophylactic allopurinol (HLA-B58), and the antiepileptic carbamazepine (HLA-B∗1502), providing a defined disease trigger and suggesting a general mechanism for these associations. We show that systemic reactions to abacavir were driven by drug-specific activation of cytokine-producing, cytotoxic CD8+ T cells. Recognition of abacavir required the transporter associated with antigen presentation and tapasin, was fixation sensitive, and was uniquely restricted by HLA-B∗5701 and not closely related HLA allotypes with polymorphisms in the antigen-binding cleft. Hence, the strong association of HLA-B∗5701 with abacavir hypersensitivity reflects specificity through creation of a unique ligand as well as HLA-restricted antigen presentation, suggesting a basis for the strong HLA class I-association with certain inflammatory disorders.

Background Mounting evidence indicates that HLA-mediated HIV evolution follows highly stereotypic pathways that result in HLA-associated footprints in HIV at the population level. However, it is not known whether characteristic HLA frequency distributions in different populations have resulted in additional unique footprints. Methods The phylogenetic dependency network model was applied to assess HLA-mediated evolution in datasets of HIV pol sequences from free plasma viruses and peripheral blood mononuclear cell (PBMC)-integrated proviruses in an immunogenetically unique cohort of Mexican individuals. Our data were compared with data from the IHAC cohort, a large multi-center cohort of individuals from Canada, Australia and the USA. Results Forty three different HLA-HIV codon associations representing 30 HLA-HIV codon pairs were observed in the Mexican cohort (q < 0.2). Strikingly, 23 (53%) of these associations differed from those observed in the well-powered IHAC cohort, strongly suggesting the existence of unique characteristics in HLA-mediated HIV evolution in the Mexican cohort. Furthermore, 17 of the 23 novel associations involved HLA alleles whose frequencies were not significantly different from those in IHAC, suggesting that their detection was not due to increased statistical power but to differences in patterns of epitope targeting. Interestingly, the consensus differed in four positions between the two cohorts and three of these positions could be explained by HLA-associated selection. Additionally, different HLA-HIV codon associations were seen when comparing HLA-mediated selection in plasma viruses and PBMC archived proviruses at the population level, with a significantly lower number of associations in the proviral dataset. Conclusion Our data support universal HLA-mediated HIV evolution at the population level, resulting in detectable HLA-associated footprints in the circulating virus. However, it also strongly suggests that unique genetic backgrounds in different HIV-infected populations may influence HIV evolution in a particular direction as particular HLA-HIV codon associations are determined by specific HLA frequency distributions. Our analysis also suggests a dynamic HLA-associated evolution in HIV with fewer HLA-HIV codon associations observed in the proviral compartment, which is likely enriched in early archived HIV sequences, compared to the plasma virus compartment. These results highlight the importance of comparative HIV evolutionary studies in immunologically different populations worldwide.

Background: The extent to which HIV replication capacity (RC) has changed over the epidemic’s course, and the influence of HLA-associated immune pressure as its driving force remains unknown. We performed a comparative study of immune escape and RC in historic (1979-1989) and modern Gag subtype B sequences from North America. Methods: Using phylogenetically-informed methods, we identified HLA-associated Gag polymorphisms in a historic cohort (N=239; 1979-1989). We also generated recombinant NL4-3 viruses encoding clonal plasma RNA Gag from 80 historic and 58 modern (2002-2008) sequences. Viral RC was measured using a GFP reporter T-cell assay and results were normalized to NL4-3 controls. Results: 95% of HLA-associated polymorphisms identified in the historic cohort were consistent with published modern escape pathways. Overall, the prevalence of HLA-associated polymorphisms in the general population increased a median 1.3-fold between historic and modern sequences; however in many cases this was influenced by differences in HLA allele frequencies between HIV-infected populations examined. Of note, the prevalence of the B*27-associated R264K escape mutation increased from 0.4 to 1.3% in the general population over time despite B*27 allele frequency remaining constant at 2.5%. Modestly lower viral RC was observed for Gag recombinant viruses constructed from pre-1985 sequences (median 0.86 [IQR 0.78-0.97], N=24) compared to those from 1985-1989 (median 0.98 [IQR 0.87-1.05], N=56) and 2002-2008 (median 0.96 [IQR 0.83-0.1.10], N=58) (p=0.049). In both historic and modern cohorts, host expression of HLA-B*27 was associated with lower RC (p=0.007). Gag codons associated with lower RC, including S67A, were identified in an exploratory analysis. Conclusion: Gag-mediated viral RC may have increased modestly since the beginning of the North American epidemic, despite limited evidence for HLA-driven viral sequence evolution during this time. Although mechanisms driving RC differences remain unclear, results do not support rapid and substantial accumulation of HLA-driven escape mutations in circulating North American HIV-1 sequences.