Inteligencia artificial en enfermedades infecciosas / Artificial intelligence in infectious diseases

Estamos asistiendo a una verdadera revolución tecnológi-ca en el campo de la salud. Los procesos basados en la aplicación de la inteligencia artificial (IA) y el aprendizaje automático (AA) están llegando progresivamente a todas las áreas disciplinares, y su aplicación en el campo de las enfermedades infecciosas es ya vertiginoso, acelerado por la pandemia de COVID-19.Hoy disponemos de herramientas que no solamente pue-den asistir o llevar adelante el proceso de toma de deci-siones basadas en guías o algoritmos, sino que también pueden modificar su desempeño a partir de los procesos previamente realizados. Desde la optimización en la identificación de microorganis-mos resistentes, la selección de candidatos a participar en ensayos clínicos, la búsqueda de nuevos agentes terapéu-ticos antimicrobianos, el desarrollo de nuevas vacunas, la predicción de futuras epidemias y pandemias, y el segui-miento clínico de pacientes con enfermedades infecciosas hasta la asignación de recursos en el curso de manejo de un brote son actividades que hoy ya pueden valerse de la inteligencia artificial para obtener un mejor resultado. El desarrollo de la IA tiene un potencial de aplicación expo-nencial y sin dudas será uno de los determinantes principa-les que moldearán la actividad médica del futuro cercano.Sin embargo, la maduración de esta tecnología, necesaria para su inserción definitiva en las actividades cotidianas del cuidado de la salud, requiere la definición de paráme-tros de referencia, sistemas de validación y lineamientos regulatorios que todavía no existen o son aún solo inci-pientes

We are in the midst of a true technological revolution in healthcare. Processes based upon artificial intelligence and machine learning are progressively touching all disciplinary areas, and its implementation in the field of infectious diseases is astonishing, accelerated by the COVID-19 pandemic. Today we have tools that can not only assist or carry on decision-making processes based upon guidelines or algorithms, but also modify its performance from the previously completed tasks. From optimization of the identification of resistant pathogens, selection of candidates for participating in clinical trials, the search of new antimicrobial therapeutic agents, the development of new vaccines, the prediction of future epidemics and pandemics, the clinical follow up of patients suffering infectious diseases up to the resource allocation in the management of an outbreak, are all current activities that can apply artificial intelligence in order to improve their final outcomes.This development has an exponential possibility of application, and is undoubtedly one of the main determinants that will shape medical activity in the future.Notwithstanding the maturation of this technology that is required for its definitive insertion in day-to-day healthcare activities, should be accompanied by definition of reference parameters, validation systems and regulatory guidelines that do not exist yet or are still in its initial stages

Clostridioides difficile infection in solid organ and hematopoietic stem cell transplant recipients: A prospective multinational study.

BACKGROUND: Clostridioides difficile infection (CDI) is a significant cause of morbidity and mortality in recipients of solid organ transplant (SOT) or hematopoietic stem cell transplant (HSCT). In retrospective single center analyses, severe disease and relapse are common. We undertook an international, prospective cohort study to estimate the response to physician determined antibiotic treatment for CDI in patients with SOT and HSCT. METHODS: Adults with a first episode of CDI within the first 2 years of SOT or HSCT were enrolled. Demographics, comorbidities, and medication history were collected, and over 90 days of follow-up clinical cure, recurrences, and complications were assessed. Logistic regression was used to study associations of baseline predictors of clinical cure and recurrence. Odds ratios (ORs) and 95% confidence intervals (CIs) are cited. RESULTS: A total of 132 patients, 81 SOT and 51 HSCT (32 allogeneic), were enrolled with a median age of 56 years; 82 (62%) were males and 128 (97%) were hospitalized at enrollment. One hundred and six (80.3%) were diagnosed by DNA assay. CDI occurred at a median of 20 days post-transplant (interquartile range, IQR: 6-133). One hundred and eight patients (81.8%) were on proton pump inhibitors; 126 patients (95.5%) received antibiotics within the 6 weeks before CDI. The most common initial CDI treatments prescribed, on or shortly before enrollment, were oral vancomycin alone (50%) and metronidazole alone (36%). Eighty-three percent (95% CI: 76, 89) of patients had clinical cure; 18% (95% CI: 12, 27) of patients had recurrent CDI; global clinical cure occurred in 65.2%. Of the 11 patients who died, two (1.5% of total) were related to CDI. In multivariable logistic regression analyses, the type of initial treatment was associated with clinical cure (p = .009) and recurrence (p = .014). A history of cytomegalovirus (CMV) after transplant was associated with increased risk of recurrence (44% with versus 13% without CMV history; OR: 5.7, 95% CI: 1.5, 21.3; p = .01). CONCLUSIONS: Among adults who develop CDI after SOT or HSCT, despite their immunosuppressed state, the percentage with clinical cure was high and the percentage with recurrence was low. Clinical cure and recurrence varied by type of initial treatment, and CMV viremia/disease was associated with an increased risk of recurrence.

Prediction of severe toxicity in adult patients under treatment with 5-fluorouracil: a prospective cohort study.

5-Fluorouracil (5-FU) has long been used for the treatment of gastrointestinal tumors harboring interindividual variability in both the pharmacokinetic and the pharmacogenetic profiles, which in turn may lead to life-threatening toxicities. We carried out a prospective cohort study of adult patients initiating treatment with 5-FU between 2013 and 2015. Primary exposures of interest were the methylenetetrahydrofolate reductase single nucleotide polymorphism in exons 4 and 7 and 5'-untranslated region-thymidylate synthase VNTR genotypes, in addition to baseline clinical and demographic variables. The primary outcome was the time to the occurrence of severe toxicity. We used a Cox regression model to evaluate patients' survival and toxicity experience and its association with baseline characteristics and a priori determined genetic polymorphisms. A total of 197 patients were included, 40.1% developed severe toxicity during follow-up. Variables that were significantly associated with developing severe toxicity were the European Organization for Research and Treatment of Cancer functional score [hazard ratio (HR): 0.98; 95% confidence interval (CI): 0.97-0.99]; type of tumor [anus (HR: 2.50; 95% CI: 1.07-5.82), head and neck/esophagus/stomach (HR: 2.95; 95% CI: 1.64-5.33)] and 5-FU continuous infusion regimens over 4-5 days (HR: 9.35; 95% CI: 2.68-32.59). We found a significant association between baseline functional status, type of tumor and continuous infusion regimens and the occurrence of severe toxicity during the follow-up of patients receiving 5-FU. No association was found with the genotypic variants evaluated. Future validation and modeling of an everyday easy-to-use score to predict toxicity among these subgroup of patients remains warranted.

Letra chica. Algunas reflexiones acerca del conflicto de intereses / Small letters. Some reflections about conflict of interest

La declaración de conflicto de intereses se ha impuesto como práctica en los últimos tiempos. Para darle un sentido concreto en nues-tro medio debemos considerar su definición y alcance, los desafíos de su implementación y su objetivo específico para establecer cuál es el men-saje que se desea transmitir. Y entrenarnos no solo como emisores sino fundamentalmente como receptores con la intención de realizar un análi-sis justo de cada situación particular.

Disclosure of conflict of interest has become a standard practice in recent times. In order to find its ultimate meaning in our scenario we should consider its definition and scope, its implementation challenges and its specific aim to define which is the message intended to be transmitted. And train ourselves not only as speakers but particularly as receptors for a fair and complete analysis of each particular situation

Which HIV patients should be screened for osteoporosis: an international perspective.

PURPOSE OF REVIEW: This review provides international insights into the real-world clinical approach to screening for bone mineral density (BMD) and osteoporosis in people living with HIV (PLWH) using opinions from HIV physicians from key regions around the world. RECENT FINDINGS: Although a significant proportion of PLWH are aged over 50, the relative importance of low BMD to clinical care differs significantly between countries and regions, based on factors such as the population at risk, access to adequate screening resources, and physicians' knowledge. Generally, management of osteoporosis in PLWH follows similar principals as for the general population, with risk factors for fracture combined with measurement of BMD by dual energy X-ray absorptiometry in algorithms such as Fracture Risk Assessment Tool, designed to provide an overall risk estimation. Although in most regions age is considered among the most important factors contributing to low BMD and fractures, considerable country and region-specific factors become apparent, such as malnutrition, inactivity and impact of comorbidities, substance abuse, and increasing use of tenofovir disoproxil fumarate. SUMMARY: These opinions highlight the diversity that still exists in the approach to the long-term management of PLWH and highlight challenges facing development of consensus guidelines that can be effectively implemented worldwide.

Water, electrolytes, and acid-base alterations in human immunodeficiency virus infected patients.

The clinical spectrum of human immunodeficiency virus (HIV) infection associated disease has changed significantly over the past decade, mainly due to the wide availability and improvement of combination antiretroviral therapy regiments. Serious complications associated with profound immunodeficiency are nowadays fortunately rare in patients with adequate access to care and treatment. However, HIV infected patients, and particularly those with acquired immune deficiency syndrome, are predisposed to a host of different water, electrolyte, and acid-base disorders (sometimes with opposite characteristics), since they have a modified renal physiology (reduced free water clearance, and relatively increased fractional excretion of calcium and magnesium) and they are also exposed to infectious, inflammatory, endocrinological, oncological variables which promote clinical conditions (such as fever, tachypnea, vomiting, diarrhea, polyuria, and delirium), and may require a variety of medical interventions (antiviral medication, antibiotics, antineoplastic agents), whose combination predispose them to undermine their homeostatic capability. As many of these disturbances may remain clinically silent until reaching an advanced condition, high awareness is advisable, particularly in patients with late diagnosis, concomitant inflammatory conditions and opportunistic diseases. These disorders contribute to both morbidity and mortality in HIV infected patients.

Impact of renal aging on drug therapy.

Elderly patients (age ≥ 65 years old) use up to 30% of all commonly prescribed medication, and they suffer more their adverse effects than the general population. In order to minimize this risk, physicians should avoid polypharmacy, dangerous pharmacological interactions and take into account pharmacodynamic and senile pharmacokinetic changes before prescribing any medication to the elderly. The present review article originally describes how renal physiology changes secondary to aging such as dysautonomia, glomerular filtration rate reduction, tubular back-filtration, sodium, calcium and magnesium loss, potassium retention, altered dilution-concentration capability, tubular frailty, genetics, internal milieu and body composition are senile changes that when combined predispose elderly people to suffer from pharmacological adverse effects. Knowledge of these physiological modifications associated with aging and their impact on the pharmacology of particular drugs may help to optimize drug use and to avoid complications in this age group.

Bone mineral density over 96 weeks in adults failing first-line therapy randomized to raltegravir/lopinavir/ritonavir compared with standard second-line therapy.

OBJECTIVE: To compare bone mineral density (BMD) changes over 96 weeks in adults virologically failing standard first-line therapy, randomized to raltegravir plus lopinavir/ritonavir (RAL + LPV/r) or conventional 2-3 nucleoside/nucleotide reverse transcriptase inhibitors [N(t)RTIs] + LPV/r second-line therapy. METHODS: Participants underwent dual-energy x-ray absorptiometry at baseline and weeks 48 and 96 to measure total hip and lumbar spine BMD. Analyses were adjusted for gender, body mass index, and smoking. Linear regression was used to compare between-group differences, logistic regression for low BMD (hip or spine Z-score ≤ -2) incidence, and multivariate linear regression to determine predictors of BMD change. This work represents the extension and final results of the previously published initial 48 weeks of the study. RESULTS: The population included 210 adults from 5 middle-income countries: 52% females, 52% Asians, 43% Africans, mean age, 39 years (SD, 8 years). In the 2-3 N(t)RTI group (vs. RAL), BMD reduction was greater at the spine (mean change, -4.9% vs. -3.5%; adjusted difference, -1.9%; 95% confidence interval: -3.3 to -0.5%, P = 0.009) and hip (-4.1% vs. -2.2%; -1.9%; -3.4 to -0.4; P = 0.012). BMD decrease was greatest at 48 weeks with stabilization to week 96. Overall, low BMD occurred in 15 participants (7.9%), with no between-group differences. Independent predictors for bone loss included lower body mass index (regression coefficient: hip, -0.18% and spine, -0.26% per 1 kg/m), longer tenofovir exposure (hip, -0.74% and spine, -1.0% per year), greater change in CD4 to week 12 (hip, -5.11% per 10-fold higher), and higher baseline HIV-RNA (spine, -0.7% per 10-fold higher). CONCLUSIONS: Over 96 weeks, there was greater BMD decrease with 2-3 N(t)RTI + LPV/r compared with RAL + LPV/r; the relative decrease at the spine was greater than the hip. BMD decreases with second-line antiretroviral therapy largely occurred in the first 48 weeks with stabilization, but no recovery thereafter.

Farmacogenómica cardiovascular / Cardiovascular pharmacogenomics

La enfermedad cardiovascular representa la primera causa de morbimortalidad a nivel mundial. Actualmente, la evidencia que sustenta la implementación de determinadas intervenciones terapéuticas se origina a partir de datos provenientes de grupos poblacionales. Sin embargo, los pacientes presentan variaciones interindividuales relacionadas tanto con la eficacia como con la toxicidad ante un mismo tratamiento farmacológico. Estas variaciones pueden ser explicadas principalmente por diferencias en la adherencia, interacciones no reconocidas y diferencias genéticas. Las alteraciones en el genoma explican entre un 20 y un 95% de la variabilidad interindividual tanto en la disponibilidad como en la respuesta a fármacos. En el tratamiento de las enfermedades cardiovasculares existen diversos ejemplos de dicha variabilidad genética interindividual y su impacto en la eficacia o toxicidad de diferentes fármacos. La variabilidad genética que determina la respuesta al clopidogrel radica fundamentalmente en el polimorfismo del citocromo (CYP) 2C19. Los polimorfismos en los genes CYP 2C9 y VKORC1 explican gran parte de la variabilidad en la respuesta a los anticoagulantes dicumarínicos. Con respecto al tratamiento hipolipidemiante, el polimorfismo del gen SLCO1B1 se ha asociado a la aparición de miopatía en pacientes tratados con simvastatina. Muchos otros polimorfismos han sido postulados pero sin un impacto clínico definido hasta la fecha. La utilización de la farmacogenómica en la práctica cotidiana ofrece la oportunidad de poder predecir toxicidad o eficacia terapéutica.

Cardiovascular disease remains a major cause of morbidity and mortality worldwide. Current medical practice takes into account information based on population studies and benefits observed in large populations or cohorts. However, individual patients present great differences in both toxicity and clinical efficacy that can be explained by variations in adherence, unknown drug to drug interactions and genetic variability. The latter seems to explain from 20% up to 95% of patient to patient variability. Treating patients with cardiovascular disorders faces the clinician with the challenge to include genomic analysis into daily practice. There are several examples within cardiovascular disease of treatments that can vary in toxicity or clinical usefulness based on genetic changes. One of the main factors affecting the efficacy of Clopidogrel is the phenotype associated with polymorphisms in the gene CYP 2C9. Furthermore, regarding oral anticoagulants, changes in CYP2C9 and VKORC1 play an important role in changing the clinical response to anticoagulation. When analyzing statin treatment, one of their main toxicities (myopathy) can be predicted by the SLCO1B1 polymorphism. The potential for prediction of toxicity and clinical efficacy from the use of genetic analysis warrants further studies aiming towards its inclusion in daily clinical practice.

HIV lipodystrophy in participants randomised to lopinavir/ritonavir (LPV/r) +2-3 nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTI) or LPV/r + raltegravir as second-line antiretroviral therapy.

OBJECTIVE: To compare changes over 48 weeks in body fat, lipids, Metabolic Syndrome and cardiovascular disease risk between patients randomised 1:1 to lopinavir/ritonavir (r/LPV) plus raltegravir (RAL) compared to r/LPV plus 2-3 nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTIs) as second-line therapy. METHODS: Participants were HIV-1 positive (>16 years) failing first-line treatment (2 consecutive HIV RNA >500 copies/mL) of NNRTI +2N(t)RTI. Whole body dual energy x-ray absorptiometry was performed at baseline and week 48. Data were obtained to calculate the Metabolic Syndrome and Framingham cardiovascular disease (CVD) risk score. Linear regression was used to compare mean differences between arms. Logistic regression compared incidence of metabolic syndrome. Associations between percent limb fat changes at 48 weeks with baseline variables were assessed by backward stepwise multivariate linear regression. Analyses were adjusted for gender, body mass index and smoking status. RESULTS: 210 participants were randomised. The mean (95% CI) increase in limb fat over 48 weeks was 15.7% (5.3, 25.9) or 0.9 kg (0.2, 1.5) in the r/LPV+N(t)RTI arm and 21.1% (11.1, 31,1) or 1.3 kg (0.7, 1.9) in the r/LPV+RAL arm, with no significant difference between treatment arms (-5.4% [-0.4 kg], p>0.1). Increases in total body fat mass (kg) and trunk fat mass (kg) were also similar between groups. Total:HDL cholesterol ratio was significantly higher in the RAL arm (mean difference -0.4 (1.4); p = 0.03), there were no other differences in lipid parameters between treatment arms. There were no statistically significant differences in CVD risk or incidence of Metabolic Syndrome between the two treatment arms. The baseline predictors of increased limb fat were high viral load, high insulin and participant's not taking lipid lowering treatment. CONCLUSION: In patients switching to second line therapy, r/LPV combined with RAL demonstrated similar improvements in limb fat as an N(t)RTI + r/LPV regimen, but a worse total:HDL cholesterol ratio over 48 weeks. TRIAL REGISTRATION: This clinical trial is registered on Clinicaltrials.gov, registry number NCT00931463 http://clinicaltrials.gov/ ct2/show/NCT00931463?term = NCT00931463&rank = 1.

Changes in inflammatory and coagulation biomarkers: a randomized comparison of immediate versus deferred antiretroviral therapy in patients with HIV infection.

OBJECTIVES: Among a subgroup of participants in the Strategies for Management of Antiretroviral Therapy (SMART) Trial that were naïve to antiretroviral therapy (ART) or off ART (6 months or longer) at study entry, risk of AIDS and serious non-AIDS events were increased for participants who deferred ART compared with those randomized to (re)initiate ART immediately. Our objective was to determine whether ART initiation in this group reduced markers of inflammation and coagulation that have been associated with increased mortality risk in SMART. Changes in these biomarkers have been described after stopping ART, but not after starting ART in SMART. METHODS: Stored specimens for 254 participants (126 drug conservation [DC] and 128 viral suppression [VS]) who were naïve to ART or off ART (6 months or longer) were analyzed for interleukin-6, high sensitivity C-reactive protein, and D-dimer at baseline and Months 2 and 6. RESULTS: At Month 6, 62% of the VS group had HIV RNA less than 400 copies/mL and median CD4 count was 190 cells/mm3 higher than for the DC group (590 versus 400 cells/mm3). Compared with DC, the VS group had 32% (95% confidence interval, 19%-43%) lower D-dimer levels at Month 6 (P < 0.001); differences were not significant for high sensitivity C-reactive protein or interleukin-6 levels. CONCLUSIONS: In this randomized comparison of immediate versus delayed ART initiation, D-dimer, but not interleukin-6 and high sensitivity C-reactive protein, declined significantly after starting ART. Further studies are needed to determine whether improvements in D-dimer are associated with reduced risk of clinical disease and whether adjunct treatments used in combination with ART can reduce inflammation among individuals with HIV infection.

Development of diagnostic criteria for serious non-AIDS events in HIV clinical trials.

PURPOSE: Serious non-AIDS (SNA) diseases are important causes of morbidity and mortality in the HAART era. We describe development of standard criteria for 12 SNA events for Endpoint Review Committee (ERC) use in START, a multicenter international HIV clinical trial. METHODS: SNA definitions were developed based upon the following: (1) criteria from a previous trial (SMART), (2) review of published literature, (3) an iterative consultation and review process with the ERC and other content experts, and (4) evaluation of draft SNA criteria using retrospectively collected reports in another trial (ESPRIT). RESULTS: Final criteria are presented for acute myocardial infarction, congestive heart failure, coronary artery disease requiring drug treatment, coronary revascularization, decompensated liver disease, deep vein thrombosis, diabetes mellitus, end-stage renal disease, non-AIDS cancer, peripheral arterial disease, pulmonary embolism, and stroke. Of 563 potential SNA events reported in ESPRIT and reviewed by an ERC, 72% met "confirmed" and 13% "probable" criteria. Twenty-eight percent of cases initially reviewed by the ERC required follow-up discussion (adjudication) before a final decision was reached. CONCLUSION: HIV clinical trials that include SNA diseases as clinical outcomes should have standardized SNA definitions to optimize event reporting and validation and should have review by an experienced ERC with opportunities for adjudication.

Efavirenz versus boosted atazanavir or zidovudine and abacavir in antiretroviral treatment-naive, HIV-infected subjects: week 48 data from the Altair study.

BACKGROUND: Antiretroviral therapy is complicated by drug interactions and contraindications. Novel regimens are needed. METHODS: This open label study randomly assigned treatment-naive, human immunodeficiency virus (HIV)-infected subjects to receive tenofovir-emtricitabine with efavirenz (Arm I), with ritonavir-boosted atazanavir (Arm II), or with zidovudine/abacavir (Arm III). Pair-wise comparisons of differences in time-weighted mean change from baseline plasma HIV-RNA to week 48 formed the primary analysis. Treatment arms were noninferior if the upper limit of the 95% confidence interval (CI) was <0.5 log(10) copies/mL. Secondary objectives included virologic, immunologic and safety end points. RESULTS: The intention-to-treat population comprised 322 patients (Arm I, n = 114; Arm II, n = 105; and Arm III, n = 103). Noninferiority for the primary end point was established. Analysis for superiority showed that Arm III was significantly less potent than Arm I (-0.20 log(10) copies/mL; 95% CI, -0.39 to -0.01 log(10) copies/mL; P = .038). The proportions of patients on each of Arm I (95%) and Arm II (96%) with <200 copies/mL were not different (P = .75), but the percentage of patients in Arm III with <200 copies/mL (82%) was significantly lower (P = .005). CD4+ cell counts did not differ. Serious adverse events were more frequent in Arm III (n = 30) than in Arm I or Arm II (n = 15 for each; P = .062). CONCLUSIONS: A novel quadruple nucleo(t)side combination demonstrated significantly less suppression of HIV replication, compared with the suppression demonstrated by standard antiretroviral therapy regimens, although it did meet the predetermined formal definition of noninferiority. Secondary analyses indicated statistically inferior virologic and safety performance. Efavirenz and ritonavir-boosted atazanavir arms were equivalent in viral suppression and safety.

Determination of the underlying cause of death in three multicenter international HIV clinical trials.

PURPOSE: Describe processes and challenges for an Endpoint Review Committee (ERC) in determining and adjudicating underlying causes of death in HIV clinical trials. METHOD: Three randomized HIV trials (two evaluating interleukin-2 and one treatment interruption) enrolled 11,593 persons from 36 countries during 1999-2008. Three ERC members independently reviewed each death report and supporting source documentation to assign underlying cause of death; differences of opinion were adjudicated. RESULTS: Of 453 deaths reported through January 14, 2008, underlying causes were as follows: 10% AIDS-defining diseases, 21% non-AIDS malignancies, 9% cardiac diseases, 9% liver disease, 8% non-AIDS-defining infections, 5% suicides, 5% other traumatic events/accidents, 4% drug overdoses/acute intoxications, 11% other causes, and 18% unknown. Major reasons for unknown classification were inadequate clinical information or supporting documentation to determine cause of death. Half (51%) of deaths reviewed by the ERC required follow-up adjudication; consensus was eventually always reached. CONCLUSION: ERCs can successfully provide blinded, independent, and systematic determinations of underlying cause of death in HIV clinical trials. Committees should include those familiar with AIDS and non-AIDS-defining diseases and have processes for adjudicating differences of opinion. Training for local investigators and procedure manuals should emphasize obtaining maximum possible documentation and follow-up information on all trial deaths.

Reporting and evaluation of HIV-related clinical endpoints in two multicenter international clinical trials.

PURPOSE: The processes for reporting and review of progression of HIV disease clinical endpoints are described for two large phase III international clinical trials. METHOD: SILCAAT and ESPRIT are multicenter randomized HIV trials evaluating the impact of interleukin-2 on disease progression and death in HIV-infected patients receiving antiretroviral therapy. We report definitions used for HIV progression of disease endpoints, procedures for site reporting of such events, processes for independent review of reported events by an Endpoint Review Committee (ERC), and the procedure for adjudication of differences of opinion between reviewers. RESULTS: Of 473 events reported through May 1, 2006, 28% were judged by an ERC to meet "confirmed" criteria and 38% to meet "probable" criteria; 34% were classified "does not meet criteria." For diseases with >5 case reports, the proportion accepted as either "confirmed" or "probable" events was highest for cervical cancer (100%), non-Hodgkin's lymphoma (88%), cryptococcosis (82%), and cryptosporidiosis (80%) and was lowest for HIV encephalopathy (25%), HIV wasting syndrome (33%), and multidermatomal herpes zoster (35%). 25% of cases required adjudication between reviewers before diagnostic certainty was assigned. CONCLUSION: Important requirements for HIV trials using clinical endpoints include objective definitions of "confirmed" and "probable," a formal reporting process with adequate information and supporting source documentation, evaluation by independent blinded reviewers, and procedures for adjudication.

Nuevos indicadores clinicos. La calidad de vida relacionada con la salud / New clinical indicators. Health-related quality of life

In the last decades the need of better measurements of health outcomes has increased the interest for new clinical indicators. Health-related quality of life (HRQoL) has emerged in this context as a multidimensional model approach where the patient is the exclusive source of information. The main objective of HRQoL measurement is to provide a global evaluation of the impact of diseases and the consequences of treatments over the daily life of the patients. The instruments developed for that purpose are questionnaires; either generic--for the comparison between different diseases-, or specific--aimed to evaluate particular conditions. These questionnaires must demonstrate several psychometric properties, such as reliability, validity, responsiveness, and for some authors also feasibility. In many areas, HRQoL studies have demonstrated to increase the knowledge of the natural history of diseases and its global consequences, beyond the classic health outcomes information based on morbidity and mortality rates. This knowledge may assist in the design of epidemiological studies and improve the comparison of strategies in therapeutic interventions. Nevertheless, some controversial issues remain such as the clinical implications of absolute scores obtained, and the need for updating the content of the instruments in accordance with the changes in natural history of diseases under evaluation

Barrera hematoencefálica y pasaje de drogas al sistema nervioso central: parte I: consideraciones generales, histológicas, bioquímicas y farmacológicas / Hematoencephalic barrier and passage of drugs into the central nervous system

El sitio anatómico de la barrera hematoencefálica es la capa de células del endotelio capilar cerebral con sus uniones estrechas ("tight junctions") intercelulares. Entonces, la capacidad de pasaje de las drogas hacia el compartimento cerebral está regida principalmente por su facilidad de atravesar la interfase lipídica de las membranas plasmáticas de dichas células, es decir su liposolubilidad. Los antibióticos, al no utilizar mecanismos especiales de transporte hematoencefálico, no escapan a esta regla. Algunos antibióticos, cuya utilización es necesaria en casos de infecciones del sistema nerviosos central -como los aminoglucósidos-, no presentan transporte adecuado a través de la barrera, y en esto se basa el desarrollo de técnicas para hacer llegar estas drogas al compartimiento cerebral, de las cuales la más difundida es la administración directa en el líquido cefalorraquídeo. De todos modos, sería interesante realizar estudios comparativos tendientes a definir la verdadera utilidad de drogas de reciente aparición, con espectro similar y mayor liposolubilidad -como las cefalosporinas modernas-, con el fin de evitar los inconvenientes derivados de la práctica de esas técnicas de soslayo de la barrera hematoencefálica