Antonio Chiesi

AIDS across Europe, 1994–98: the EuroSIDA study

BACKGROUND The clinical presentation of HIV-1 related diseases could have changed after the introduction of highly active antiretroviral treatment (HAART). We aimed to assess changes over time in the incidence of ADIs overall and within CD4 lymphocyte count strata, the relationship with treatment and degree of immunodeficiency at diagnosis of ADIs. METHODS We did a prospective observational multicentre study of over 7300 patients in 52 European HIV-1 outpatient clinics. Incidence rates per 100 patient-years of observation were calculated. FINDINGS In total, we recorded 1667 new ADIs; the incidence of ADIs declined from 30.7 per 100 patient-years of observation during 1994 (95% CI 28.0-33.4) to 2.5 per 100 patient-years of observation during 1998 (95% CI 2.0-3.0, p<0.0001, test for trend). Median CD4 lymphocyte count at diagnosis of a new ADI increased from 28 cells/microL to 125 cells/microL between 1994 and 1998 (p<0.0001), yet a steep decline in the rate of ADIs was seen after stratification by latest CD4 lymphocyte count within each year (< or = 50, 51-200, and > 200 cells/microL). Patients on HAART had a lower rate of ADIs than patients not on this treatment within each CD4 lymphocyte count strata. The proportion of ADIs attributable to cytomegalovirus retinitis and Mycobacterium avium complex declined over time (p=0.0058 and 0.0022, respectively), whereas the proportion of diagnoses attributable to non-Hodgkin lymphoma has increased (p<0.0001). In 1994, less than 4% of ADIs were non-Hodgkin lymphoma, in 1998 the proportion was almost 16%. This condition has become one of the most common ADIs in patients on HAART. INTERPRETATION Our findings lend support to the idea that treatment regimens can lower the incidence of ADIs. The immediate risk of an ADI for a given CD4 lymphocyte count has declined over time and is lower among patients on HAART. Long-term follow-up of patients on combination treatment is essential to monitor the incidence of new and emerging diagnoses.

Influence of Age on CD4 Cell Recovery in Human Immunodeficiency Virus–Infected Patients Receiving Highly Active Antiretroviral Therapy: Evidence from the EuroSIDA Study

Influence of age on the CD4 cell response to highly active antiretroviral therapy (HAART) was examined in 1956 patients (median age, 37.2 years) in the EuroSIDA study. Median initial CD4 cell count was 192x106 cells/L, follow-up was 31 months, and time to maximum CD4 cell response was 20 months. Age groups were not different for baseline CD4 cell count, baseline human immunodeficiency virus RNA load, or treatment history. CD4 cell increase, stratified by age quartiles, differed during months 3-36 of HAART (P=.023). Maximum CD4 cell increase from start of HAART differed by age group (P=.0003), as did maximum CD4 cell count (P<10-4). Multivariate analysis confirmed the inverse relationship between age and maximum CD4 cell response (P=.023). Time to a CD4 increase of >200x106 cells/L was shorter for patients in the younger age groups (P=.0026), as confirmed by multivariate analysis (P<10-4). Younger age may favor CD4 cell restoration because of preserved thymic function.

Serious Fatal and Nonfatal Non-AIDS-Defining Illnesses in Europe

Background:Little is known about the incidence and risk factors for serious non-AIDS-defining events. Methods:The incidence of non-AIDS events (malignancies, end-stage renal disease, liver failure, pancreatitis, cardiovascular disease), and AIDS after January 1, 2001, was calculated; Poisson regression was used to investigate factors associated with non-AIDS and AIDS. Results:Among 12,844 patients, 1058 were diagnosed with a non-AIDS event [incidence 1.77 per 100 person-years of follow-up; 95% confidence interval (CI): 1.66 to 1.87]; 462 patients (43.7%) died. The incidence of AIDS (1025 diagnoses; 339 deaths, 33.1%) was 1.72 per 100 person-years of follow-up (1.61 to 1.83). After adjustment, older age [incidence rate ratio (IRR): 1.71 per 10 years older, 95% CI: 1.60 to 1.83], diabetes (IRR: 1.49, 95% CI: 1.22 to 1.82) and hypertension (IRR: 1.63, 95% CI: 1.43 to 1.87) were associated with non-AIDS events. Compared with patients without an event, there was a 4-fold increased risk of death after an AIDS event (relative hazard: 4.14; 95% CI 3.47 to 4.94) and almost a 7-fold increased risk of death after a non-AIDS event (relative hazard: 6.72; 95% CI: 5.61 to 8.05). Conclusions:Non-AIDS events were common in the combination antiretroviral therapy era and associated with considerably mortality. Evidence on the impact of modifying immunodeficiency and lifestyle-related factors on the risk of non-AIDS events in HIV-infected persons is an important but unmet research need.

Gender differences in clinical progression of HIV-1-infected individuals during long-term highly active antiretroviral therapy

Objective: To assess gender differences in the long-term clinical, virological and immunological outcomes during highly active antiretroviral therapy (HAART). Methods: This longitudinal observational multicentre study followed 2460 HIV-infected patients who had begun a protease inhibitor-based regimen for a median period of 43 months. Outcome measures were virological suppression (< 500 copies/ml), confirmed virological rebound after suppression, and death or new AIDS-defining illness (ADI). Results: At baseline, 690 female patients (28.0%) had significantly lower age, higher prevalence of heterosexual contact and lower prevalence of intravenous drug use as risk factors for HIV infection compared with males. Furthermore, females had a lower number of AIDS-defining illnesses, higher CD4 cell counts and lower viral loads. No gender differences were reported in terms of proportion of patients achieving viral suppression or exhibiting rebound after achieving viral suppression. Female patients experienced reduced clinical progression during follow-up compared with males (P = 0.008) by Kaplan–Meier analysis; however this difference was not significant in an adjusted analysis. In a multivariate model, the interaction between gender and risk factor for HIV or viral load showed that female drug users and female patients with a baseline HIV RNA viral load of 104–105 copies/ml had a favourable clinical outcome compared with males (P = 0.035 and P = 0.015, respectively). Conclusion: No differences were found between genders in terms of virological and immunological outcomes during long-term HAART. Nevertheless, a lower risk of clinical progression was reported among female patients with intermediate baseline viral load than in males.

Virologic, immunologic, and clinical response to highly active antiretroviral therapy: the gender issue revisited

Background: Highly active antiretroviral therapy (HAART) has dramatically improved the prognosis for patients with HIV. There is ongoing debate over a potential gender effect on patient outcome after HAART. Methods: Individuals were from the EuroSIDA cohort, naive to protease inhibitors and nonnucleoside reverse transcriptase inhibitors, and had at least one viral load and CD4 measurement prior to starting HAART. Endpoints were virologic (time to <500 copies/mL, time to rebound [first of two consecutive viral loads >500 copies/mL]), immunologic (time to a 100/mm cell rise in CD4 count) and clinical (time to new AIDS and death). Hazard ratios (HR), derived using Cox regression models, compared female to male rates of achieving endpoints. Results: Of 2547 patients, 20% (511) were female. Significantly more females than males were nonwhite (24% vs. 10%, p < .001). Males were older (median age 39 vs. 35 years, p < .0001), had lower CD4 counts (211 vs. 240/mm, p = .03), higher viral loads (4.6 vs. 4.4 log copies/mL, p < .0001), were more likely to have a history of AIDS (26% vs. 18%, p < .001) and were more likely to be treatment‐naive (34% vs. 29%, p = .03). Adjusted HR for association between gender (comparing females with males) and the outcomes studied were as follows: for reaching <500 copies/mL 0.91 (0.81‐1.03, p = .17), rebound 1.17 (0.95‐1.44, p = .15), for 100 cell CD4 count rise 1.02 (0.88‐1.14, p = .99), for progression to new AIDS 1.12 (0.73‐1.71, p = .59) and for time to death 1.15 (0.69‐1.92, p = .57). Conclusions: We found no significant evidence of a gender difference in virologic, immunologic, or clinical outcomes after starting HAART.

Comparison of serum exosome isolation methods for microRNA profiling.

OBJECTIVES Exosomes are small membrane bound vesicles secreted by most cell types. Exosomes contain various functional proteins, mRNAs and microRNAs (miRNAs) that could be used for diagnostic and therapeutic purposes. Currently, a standard method for serum exosome isolation is differential ultracentrifugation, but a search for alternative, less time-consuming and labour extensive exosomal isolation method for use in clinical settings is ongoing. The effect of serum exosome isolation method on obtained miRNA profile is not yet clear. The aim of this study was to determine to which extent selected exosome isolation methods influence the serum exosomal miRNA profile. DESIGN AND METHODS Exosomes were isolated from blood serum of healthy individuals by ultracentrifugation and ExoQuick Precipitation methods. The expression profile of 375 miRNAs was determined by real time PCR using Exiqon miRCURY LNA™ microRNA Human panel I assays. RESULTS Although a strong correlation of exosomal miRNA profiles was observed between the two isolation methods, distinct clusters of miRNA levels between the used methods were identified. The detected levels of two miRNAs, miR-92a and miR-486-5p, were significantly influenced by the exosome isolation method used. CONCLUSIONS Both exosome isolation methods are suitable for serum exosomal miRNA profiling. Differences found in miRNA patterns between the two methods indicate that the observed exosomal miRNA profile is slightly affected by the extracellular vesicle isolation method.

Time to Virological Failure of 3 Classes of Antiretrovirals after Initiation of Highly Active Antiretroviral Therapy: Results from the EuroSIDA Study Group

OBJECTIVE The purpose of the present study was to determine the prevalence and incidence of virological triple drug-class failure (TCF) and to summarize the clinical outcome for patients who started receiving highly active antiretroviral therapy (HAART). METHODS The present study is an observational longitudinal study of 3496 treatment-experienced (TE) and treatment-naive (TN) patients monitored from the time they started receiving HAART (baseline) until TCF occurred (as determined on the basis of viral loads), until AIDS was newly diagnosed, or until death. RESULTS Four hundred forty-five patients (12.7%) had TCF; 370 (16.6%) of 2230 patients were TE, and 75 (5.9%) of 1266 patients were TN. At 6 years after starting HAART, 21.4% of TE and 11.2% of TN patients had TCF (P<.0001). The prevalence of TCF at or after 2002 was 15.5% in TE patients and 4.8% in TN patients. TN patients had a 32% annual increase in the incidence of TCF (95% confidence interval [CI], 14%-54%; P<.0001); at 5 years after starting HAART, the rate was comparable for TE and TN patients (3.3 and 3.4 cases/100 person-years of follow-up [PYFU], respectively). The incidence of new cases of AIDS or death was 2.7 cases/100 PYFU in patients who did not experience TCF and 5.0 cases/100 PYFU in patients who did experience TCF, an estimated 36% increase with each category of TCF (95% CI, 19%-56%; P<.0001). CONCLUSION The prevalence of TCF was low after patients started receiving HAART, particularly among TN patients. Despite the influx of patients who had started receiving HAART more recently, the prevalence of TCF increased over calendar time. Patients with TCF had a higher incidence of newly diagnosed AIDS or death. Treatment of patients with TCF deserves further investigation.

Exosomes: the ideal nanovectors for biodelivery

Abstract Nanomedicine aims to exploit the improved and often novel physical, chemical, and biological properties of materials at the nanometric scale, possibly with the highest level of biomimetism, an approach that simulates what occurs in nature. Although extracellularly released vesicles include both microvesicles (MVs) and exosomes, only exosomes have the size that may be considered suitable for potential use in nanomedicine. In fact, recent reports have shown that exosomes are able to interact with target cells within an organ or at a distance using different mechanisms. Much is yet to be understood about exosomes, and currently, we are looking at the visible top of an iceberg, with most of what we have to understand on these nanovesicles still under the sea. In fact, we know that exosomes released by normal cells always trigger positive effects, whereas those released by cells in pathological condition, such as tumor or infected cells, may induce undesired, dangerous, and mostly unknown effects, but we cannot exclude the possibility that exosomes may also be detrimental for the body in normal conditions. However, whether we consider extracellular vesicles as a whole, thus including MVs, it appears that even in normal conditions, extracellular vesicles may lead to unwanted effects, depending on gender and age. This review aims to critically emphasize existing data in the literature that support the possible roles of exosomes in both diagnostic and therapeutic scopes.

Integrated isolation and quantitative analysis of exosome shuttled proteins and nucleic acids using immunocapture approaches

Clinical implementation of exosome based diagnostic and therapeutic applications is still limited by the lack of standardized technologies that integrate efficient isolation of exosomes with comprehensive detection of relevant biomarkers. Conventional methods for exosome isolation based on their physical properties such as size and density (filtration, ultracentrifugation or density gradient), or relying on their differential solubility (chemical precipitation) are established primarily for processing of cell supernatants and later adjusted to complex biological samples such as plasma. Though still representing gold standard in the field, these methods are clearly suboptimal for processing of routine clinical samples and have intrinsic limits that impair their use in biomarker discovery and development of novel diagnostics. Immunoisolation (IA) offers unique advantages for the recovery of exosomes from complex and viscous fluids, in terms of increased efficiency and specificity of exosome capture, integrity and selective origin of isolated vesicles. We have evaluated several commercially available solutions for immunoplate- and immunobead-based affinity isolation and have further optimized protocols to decrease non-specific binding due to exosomes complexity and matrix contaminants. In order to identify best molecular targets for total exosome capture from diverse biological sources, as well as for selective enrichment in populations of interest (e.g. tumor derived exosomes) several exosome displayed proteins and respective antibodies have been evaluated for plate and bead functionalisation. Moreover, we have optimized and directly implemented downstream steps allowing on-line quantification and characterization of bound exosome markers, namely proteins and RNAs. Thus assembled assays enabled rapid overall quantification and validation of specific exosome associated targets in/on plasma exosomes, with multifold increased yield and enrichment ratio over benchmarking technologies. Assays directly coupling selective immobilization of exosomes to a solid phase and their immune- and or molecular profiling through conventional ELISA and PCR analysis, resulted in easy-to-elaborate, quantitative readouts, with high low-end sensitivity and dynamic range, low costs and hands-on time, minimal sample handling and downscaling of a working plasma volumes to as few as 100 μl.

Changes in hospital admissions across Europe: 1995-2003. Results from the EuroSIDA study

To describe changes in the proportions of patients admitted to hospital and the duration of admission during the month of March between 1995 and 2003 and to describe the factors related to admission for 9802 patients from EuroSIDA, a pan‐European, observational cohort study.