Liliana Orellana

Sex differences in the Toll-like receptor–mediated response of plasmacytoid dendritic cells to HIV-1

Manifestations of viral infections can differ between women and men, and marked sex differences have been described in the course of HIV-1 disease. HIV-1–infected women tend to have lower viral loads early in HIV-1 infection but progress faster to AIDS for a given viral load than men. Here we show substantial sex differences in the response of plasmacytoid dendritic cells (pDCs) to HIV-1. pDCs derived from women produce markedly more interferon-α (IFN-α) in response to HIV-1–encoded Toll-like receptor 7 (TLR7) ligands than pDCs derived from men, resulting in stronger secondary activation of CD8+ T cells. In line with these in vitro studies, treatment-naive women chronically infected with HIV-1 had considerably higher levels of CD8+ T cell activation than men after adjusting for viral load. These data show that sex differences in TLR-mediated activation of pDCs may account for higher immune activation in women compared to men at a given HIV-1 viral load and provide a mechanism by which the same level of viral replication might result in faster HIV-1 disease progression in women compared to men. Modulation of the TLR7 pathway in pDCs may therefore represent a new approach to reduce HIV-1–associated pathology.

International study to evaluate PCR methods for detection of Trypanosoma cruzi DNA in blood samples from Chagas disease patients

Background A century after its discovery, Chagas disease still represents a major neglected tropical threat. Accurate diagnostics tools as well as surrogate markers of parasitological response to treatment are research priorities in the field. The purpose of this study was to evaluate the performance of PCR methods in detection of Trypanosoma cruzi DNA by an external quality evaluation. Methodology/Findings An international collaborative study was launched by expert PCR laboratories from 16 countries. Currently used strategies were challenged against serial dilutions of purified DNA from stocks representing T. cruzi discrete typing units (DTU) I, IV and VI (set A), human blood spiked with parasite cells (set B) and Guanidine Hidrochloride-EDTA blood samples from 32 seropositive and 10 seronegative patients from Southern Cone countries (set C). Forty eight PCR tests were reported for set A and 44 for sets B and C; 28 targeted minicircle DNA (kDNA), 13 satellite DNA (Sat-DNA) and the remainder low copy number sequences. In set A, commercial master mixes and Sat-DNA Real Time PCR showed better specificity, but kDNA-PCR was more sensitive to detect DTU I DNA. In set B, commercial DNA extraction kits presented better specificity than solvent extraction protocols. Sat-DNA PCR tests had higher specificity, with sensitivities of 0.05–0.5 parasites/mL whereas specific kDNA tests detected 5.10−3 par/mL. Sixteen specific and coherent methods had a Good Performance in both sets A and B (10 fg/µl of DNA from all stocks, 5 par/mL spiked blood). The median values of sensitivities, specificities and accuracies obtained in testing the Set C samples with the 16 tests determined to be good performing by analyzing Sets A and B samples varied considerably. Out of them, four methods depicted the best performing parameters in all three sets of samples, detecting at least 10 fg/µl for each DNA stock, 0.5 par/mL and a sensitivity between 83.3–94.4%, specificity of 85–95%, accuracy of 86.8–89.5% and kappa index of 0.7–0.8 compared to consensus PCR reports of the 16 good performing tests and 63–69%, 100%, 71.4–76.2% and 0.4–0.5, respectively compared to serodiagnosis. Method LbD2 used solvent extraction followed by Sybr-Green based Real time PCR targeted to Sat-DNA; method LbD3 used solvent DNA extraction followed by conventional PCR targeted to Sat-DNA. The third method (LbF1) used glass fiber column based DNA extraction followed by TaqMan Real Time PCR targeted to Sat-DNA (cruzi 1/cruzi 2 and cruzi 3 TaqMan probe) and the fourth method (LbQ) used solvent DNA extraction followed by conventional hot-start PCR targeted to kDNA (primer pairs 121/122). These four methods were further evaluated at the coordinating laboratory in a subset of human blood samples, confirming the performance obtained by the participating laboratories. Conclusion/Significance This study represents a first crucial step towards international validation of PCR procedures for detection of T. cruzi in human blood samples.

Estimation and extrapolation of optimal treatment and testing strategies

We review recent developments in the estimation of an optimal treatment strategy or regime from longitudinal data collected in an observational study. We also propose novel methods for using the data obtained from an observational database in one health-care system to determine the optimal treatment regime for biologically similar subjects in a second health-care system when, for cultural, logistical, or financial reasons, the two health-care systems differ (and will continue to differ) in the frequency of, and reasons for, both laboratory tests and physician visits. Finally, we propose a novel method for estimating the optimal timing of expensive and/or painful diagnostic or prognostic tests. Diagnostic or prognostic tests are only useful in so far as they help a physician to determine the optimal dosing strategy, by providing information on both the current health state and the prognosis of a patient because, in contrast to drug therapies, these tests have no direct causal effect on disease progression. Our new method explicitly incorporates this no direct effect restriction.

Dynamic Regime Marginal Structural Mean Models for Estimation of Optimal Dynamic Treatment Regimes, Part I: Main Content

Dynamic treatment regimes are set rules for sequential decision making based on patient covariate history. Observational studies are well suited for the investigation of the effects of dynamic treatment regimes because of the variability in treatment decisions found in them. This variability exists because different physicians make different decisions in the face of similar patient histories. In this article we describe an approach to estimate the optimal dynamic treatment regime among a set of enforceable regimes. This set is comprised by regimes defined by simple rules based on a subset of past information. The regimes in the set are indexed by a Euclidean vector. The optimal regime is the one that maximizes the expected counterfactual utility over all regimes in the set. We discuss assumptions under which it is possible to identify the optimal regime from observational longitudinal data. Murphy et al. (2001) developed efficient augmented inverse probability weighted estimators of the expected utility of one fixed regime. Our methods are based on an extension of the marginal structural mean model of Robins (1998, 1999) which incorporate the estimation ideas of Murphy et al. (2001). Our models, which we call dynamic regime marginal structural mean models, are specially suitable for estimating the optimal treatment regime in a moderately small class of enforceable regimes of interest. We consider both parametric and semiparametric dynamic regime marginal structural models. We discuss locally efficient, double-robust estimation of the model parameters and of the index of the optimal treatment regime in the set. In a companion paper in this issue of the journal we provide proofs of the main results.

Atmospheric quality and distribution of heavy metals in Argentina employing Tillandsia capillaris as a biomonitor

The atmospheric quality and distribution of heavy metals were evaluated throughout a wide region of Argentina. In addition, the biomonitor performance of Tillandsia capillaris Ruiz & Pav. f. capillaris was studied in relation to the accumulation of heavy metals and to its physiologic response to air pollutants. A sampling area of 50,000 km2 was selected in the central region of the Argentine Republic. This area was subdivided into grids of 25 x 25 km. Pools of T. capillaris, where present, were collected at each intersection point. From each pool three sub-samples were analyzed independently. Furthermore, five replicates were collected at 20% of the points in order to analyze the variability within the site. The content of Co, Cu, Fe, Ni, Mn, Pb and Zn was determined by Atomic Absorption Spectrometry. Chemical-physiological parameters were also determined to detect symptoms of foliar damage. Chlorophylls, phaeophytins, hydroperoxy conjugated dienes, malondialdehyde and sulfur were quantified in T. capillaris. Some of these parameters were used to calculate a foliar damage index. Data sets were evaluated by one-way ANOVA, correlation analysis, principal component analysis and mapping. Geographical distribution patterns were obtained for the different metals reflecting the contribution of natural and anthropogenic emission sources. According to our results it can be inferred that Fe, Mn and Co probably originated in the soil. For Pb, the highest values were found in the mountainous area, which can be attributed to the presence of Pb in the granitic rocks. Ni showed mainly an anthropogenic origin, with higher values found in places next to industrial centers. For Zn the highest values were in areas of agricultural development. The same was observed for Cu, whose presence could be related to the employment of pesticides. The foliar damage index distribution map showed that the central and southeastern zones were the ones where the major damage in the bioindicator was found. The central zone coincides with the city of Córdoba whereas the southeastern area is strictly agricultural, so the high values found there could be related to the use of pesticides.

Differences in Parent-Provider Concordance Regarding Prognosis and Goals of Care Among Children With Advanced Cancer

PURPOSE Concordance between parents of children with advanced cancer and health care providers has not been described. We aimed to describe parent-provider concordance regarding prognosis and goals of care, including differences by cancer type. PATIENTS AND METHODS A total of 104 pediatric patients with recurrent or refractory cancer were enrolled at three large children’s hospitals. On enrollment, their parents and providers were invited to complete a survey assessing perceived prognosis and goals of care. Patients’ survival status was retrospectively abstracted from medical records. Concordance was assessed via discrepancies in perceived prognosis, statistics, and McNemar’s test. Distribution of categorical variables and survival rates across cancer type were compared with Fisher’s exact and log-rank tests, respectively. RESULTS Data were available from 77 dyads (74% of enrolled). Parent-provider agreement regarding prognosis and goals of care was poor (kappa, 0.12 to 0.30). Parents were more likely to report cure was likely (P < .001). The frequency of perceived likelihood of cure and the goal of cure varied by cancer type for both parents and providers (P < .001 to .004). Relatively optimistic responses were more common among parents and providers of patients with hematologic malignancies, although there were no differences in survival. CONCLUSION Parent-provider concordance regarding prognosis and goals in advanced pediatric cancer is generally poor. Perceptions of prognosis and goals of care vary by cancer type. Understanding these differences may inform parent-provider communication and decision making.

Effect of self-collection of HPV DNA offered by community health workers at home visits on uptake of screening for cervical cancer (the EMA study): a population-based cluster-randomised trial

BACKGROUND Control of cervical cancer in developing countries has been hampered by a failure to achieve high screening uptake. HPV DNA self-collection could increase screening coverage, but implementation of this technology is difficult in countries of middle and low income. We investigated whether offering HPV DNA self-collection during routine home visits by community health workers could increase cervical screening. METHODS We did a population-based cluster-randomised trial in the province of Jujuy, Argentina, between July 1, 2012, and Dec 31, 2012. Community health workers were eligible for the study if they scored highly on a performance score, and women aged 30 years or older were eligible for enrolment by the community health worker. 200 community health workers were randomly allocated in a 1:1 ratio to either the intervention group (offered women the chance to self-collect a sample for cervical screening during a home visit) or the control group (advised women to attend a health clinic for cervical screening). The primary outcome was screening uptake, measured as the proportion of women having any HPV screening test within 6 months of the community health worker visit. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT02095561. FINDINGS 100 community health workers were randomly allocated to the intervention group and 100 were assigned to the control group; nine did not take part. 191 participating community health workers (94 in the intervention group and 97 in the control group) initially contacted 7650 women; of 3632 women contacted by community health workers in the intervention group, 3049 agreed to participate; of 4018 women contacted by community health workers in the control group, 2964 agreed to participate. 2618 (86%) of 3049 women in the intervention group had any HPV test within 6 months of the community health worker visit, compared with 599 (20%) of 2964 in the control group (risk ratio 4·02, 95% CI 3·44-4·71). INTERPRETATION Offering self-collection of samples for HPV testing by community health workers during home visits resulted in a four-fold increase in screening uptake, showing that this strategy is effective to improve cervical screening coverage. This intervention reduces womens barriers to screening and results in a substantial and rapid increase in coverage. Our findings suggest that HPV testing could be extended throughout Argentina and in other countries to increase cervical screening coverage. FUNDING Instituto Nacional del Cáncer (Argentina).

Symptoms and Distress in Children With Advanced Cancer: Prospective Patient-Reported Outcomes From the PediQUEST Study

PURPOSE Thousands of children are living with advanced cancer; yet patient-reported outcomes (PROs) have rarely been used to describe their experiences. We aimed to describe symptom distress in 104 children age 2 years or older with advanced cancer enrolled onto the Pediatric Quality of Life and Evaluation of Symptoms Technology (PediQUEST) Study (multisite clinical trial evaluating an electronic PRO system). METHODS Symptom data were collected using age- and respondent-adapted versions of the PediQUEST Memorial Symptom Assessment Scale (PQ-MSAS) at most once per week. Clinical and treatment data were obtained from medical records. Individual symptom scores were dichotomized into high/low distress. Determinants of PQ-MSAS scores were explored using linear mixed-effects models. RESULTS During 9 months of follow-up, PQ-MSAS was administered 920 times: 459 times in teens (99% self-report), 249 times in children ages 7 to 12 years (96% child/parent report), and 212 times in those ages 2 to 6 years (parent reports). Common symptoms included pain (48%), fatigue (46%), drowsiness (39%), and irritability (37%); most scores indicated high distress. Among the 73 PQ-MSAS surveys administered in the last 12 weeks of life, pain was highly prevalent (62%; 58% with high distress). Being female, having a brain tumor, experiencing recent disease progression, and receiving moderate- or high-intensity cancer-directed therapy in the prior 10 days were associated with worse PQ-MSAS scores. In the final 12 weeks of life, receiving mild cancer-directed therapy was associated with improved psychological PQ-MSAS scores. CONCLUSION Children with advanced cancer experience high symptom distress. Strategies to promote intensive symptom management are indicated, especially with disease progression or administration of intensive treatments.

Improving the Care of Children With Advanced Cancer by Using an Electronic Patient-Reported Feedback Intervention: Results From the PediQUEST Randomized Controlled Trial

PURPOSE This study aimed to determine whether feeding back patient-reported outcomes (PROs) to providers and families of children with advanced cancer improves symptom distress and health-related quality of life (HRQoL). PATIENTS AND METHODS This study was a parallel, multicentered pilot randomized controlled trial. At most once per week, children age ≥ 2 years old with advanced cancer or their parent completed the computer-based Pediatric Quality of Life and Evaluation of Symptoms Technology (PediQUEST) survey consisting of age- and respondent-adapted versions of the Memorial Symptom Assessment Scale (MSAS), Pediatric Quality of Life Inventory 4.0 Generic Core Scales (PedsQL4.0), and an overall Sickness question. In the intervention group (n = 51), oncologists and families received printed reports summarizing PROs; e-mails were sent to oncologists and subspecialists when predetermined scores were exceeded. No feedback was provided in the control group (n = 53). Primary outcomes included linear trends of MSAS, PedsQL4.0 total and subscale scores, and Sickness scores during 20 weeks of follow-up, along with child, parent, and provider satisfaction with PediQUEST feedback. RESULTS Feedback did not significantly affect average MSAS, PedsQL4.0, or Sickness score trends. Post hoc subgroup analyses among children age ≥ 8 years who survived 20 weeks showed that feedback improved PedsQL4.0 emotional (+8.1; 95% CI, 1.8 to 14.4) and Sickness (-8.2; 95% CI, -14.2 to -2.2) scores. PediQUEST reports were valued by children, parents, and providers and contributed at least sometimes to physician initiation of a psychosocial consult (56%). CONCLUSION Although routine feedback of PROs did not significantly affect the childs symptoms or HRQoL, changes were in expected directions and improvements observed in emotional HRQoL through exploratory analyses were encouraging. Importantly, children, parents, and providers value PRO feedback.

Analysis of serious non‐AIDS events among HIV‐infected adults at Latin American sites

Acquired immune deficiency appears to be associated with serious non‐AIDS (SNA)‐defining conditions such as cardiovascular disease, liver and renal insufficiency and non‐AIDS‐related malignancies. We analysed the incidence of, and factors associated with, several SNA events in the LATINA retrospective cohort.