Publications

In humans, immunity to Plasmodium sp. generally takes the form of protection from symptomatic malaria (i.e., 'clinical immunity') rather than infection ('sterilizing immunity'). In contrast, mice infected with Plasmodium develop sterilizing immunity, hindering progress in understanding the mechanistic basis of clinical immunity. Here we present a novel model in which mice persistently infected with P. chabaudi exhibit limited clinical symptoms despite sustaining patent parasite burdens for many months. Characterization of immune responses in persistently infected mice revealed development of CD4+ T cell exhaustion, increased production of IL-10, and expansion of B cells with an atypical surface phenotype. Additionally, persistently infected mice displayed a dramatic increase in circulating nonclassical monocytes, a phenomenon that we also observed in humans with both chronic Plasmodium exposure and asymptomatic infection. Following pharmacological clearance of infection, previously persistently infected mice could not control a secondary challenge, indicating that persistent infection disrupts the sterilizing immunity that typically develops in mouse models of acute infection. This study establishes an animal model of asymptomatic, persistent Plasmodium infection that recapitulates several central aspects of the immune response in chronically exposed humans. As such, it provides a novel tool for dissection of immune responses that may prevent development of sterilizing immunity and limit pathology during infection.

Gender-based power imbalances place women at significant risk for sexual violence, however, little research has examined this association among women living with HIV/AIDS. We performed a cross-sectional analysis of relationship power and sexual violence among HIV-positive women on anti-retroviral therapy in rural Uganda. Relationship power was measured using the Sexual Relationship Power Scale (SRPS), a validated measure consisting of two subscales: relationship control (RC) and decision-making dominance. We used multivariable logistic regression to test for associations between the SRPS and two dependent variables: recent forced sex and transactional sex. Higher relationship power (full SRPS) was associated with reduced odds of forced sex (AOR = 0.24; 95 % CI 0.07-0.80; p = 0.020). The association between higher relationship power and transactional sex was strong and in the expected direction, but not statistically significant (AOR = 0.47; 95 % CI 0.18-1.22; p = 0.119). Higher RC was associated with reduced odds of both forced sex (AOR = 0.18; 95 % CI 0.06-0.59; p < 0.01) and transactional sex (AOR = 0.38; 95 % CI 0.15-0.99; p = 0.048). Violence prevention interventions with HIV-positive women should consider approaches that increase women's power in their relationships.

BACKGROUND

Genome-wide association studies (GWAS) in European populations have identified genetic risk variants associated with multiple myeloma.

METHODS

We performed association testing of common variation in eight regions in 1,318 patients with multiple myeloma and 1,480 controls of European ancestry and 1,305 patients with multiple myeloma and 7,078 controls of African ancestry and conducted a meta-analysis to localize the signals, with epigenetic annotation used to predict functionality.

RESULTS

We found that variants in 7p15.3, 17p11.2, 22q13.1 were statistically significantly (P < 0.05) associated with multiple myeloma risk in persons of African ancestry and persons of European ancestry, and the variant in 3p22.1 was associated in European ancestry only. In a combined African ancestry-European ancestry meta-analysis, variation in five regions (2p23.3, 3p22.1, 7p15.3, 17p11.2, 22q13.1) was statistically significantly associated with multiple myeloma risk. In 3p22.1, the correlated variants clustered within the gene body of ULK4 Correlated variants in 7p15.3 clustered around an enhancer at the 3' end of the CDCA7L transcription termination site. A missense variant at 17p11.2 (rs34562254, Pro251Leu, OR, 1.32; P = 2.93 × 10) in TNFRSF13B encodes a lymphocyte-specific protein in the TNF receptor family that interacts with the NF-κB pathway. SNPs correlated with the index signal in 22q13.1 cluster around the promoter and enhancer regions of CBX7 CONCLUSIONS: We found that reported multiple myeloma susceptibility regions contain risk variants important across populations, supporting the use of multiple racial/ethnic groups with different underlying genetic architecture to enhance the localization and identification of putatively functional alleles.

IMPACT

A subset of reported risk loci for multiple myeloma has consistent effects across populations and is likely to be functional. Cancer Epidemiol Biomarkers Prev; 25(12); 1609-18. ©2016 AACR.

Care transitions from the hospital to home remain a vulnerable time for many patients, especially for those with heart failure (CHF) and chronic obstructive pulmonary disease (COPD). Despite regular use in chronic disease management, it remains unclear how technology can best support patients during their transition from the hospital. We sought to evaluate the impact of a technology-supported care transition support program on hospitalizations, days out of the community and mortality. Using a pragmatic randomized trial, we enrolled patients (511 enrolled, 478 analyzed) hospitalized with CHF/COPD to "E-Coach," an intervention with condition-specific customization and in-hospital and post-discharge support by a care transition nurse (CTN), interactive voice response post-discharge calls, and CTN follow-up versus usual post-discharge care (UC). The primary outcome was 30-day rehospitalization. Secondary outcomes included (1) rehospitalization and death and (2) days in the hospital and out of the community. E-Coach and UC groups were similar at baseline except for gender imbalance (p = 0.02). After adjustment for gender, our primary outcome, 30-day rehospitalization rates did not differ between the E-Coach and UC groups (15.0 vs. 16.3 %, adjusted hazard ratio [95 % confidence interval]: 0.94 [0.60, 1.49]). However, in the COPD subgroup, E-Coach was associated with significantly fewer days in the hospital (0.5 vs. 1.6, p = 0.03). E-Coach, an IVR-augmented care transition intervention did not reduce rehospitalization. The positive impact on our secondary outcome (days in hospital) among COPD patients, but not in CHF, may suggest that E-Coach may be more beneficial among patients with COPD.NIH trial registry number: NCT01135381Trial Protocol: http://dx.doi.org/ 10.1016/j.cct.2012.08.007.

BACKGROUND

Thirty-day readmission following heart failure hospitalization impacts hospital performance measures and reimbursement. We investigated readmission characteristics and the magnitude of 30-day hospital readmissions after hospital discharge for heart failure using the Healthcare Cost and Utilization Project State Inpatient Databases (SID).

METHODS

Adults aged ≥ 40 years hospitalized with a primary discharge diagnosis of heart failure from 2007-2011 were identified in the California, New York, and Florida SIDs. Characteristics of patients with and without 7-, 8 to 30-, and 30-day readmission, and primary readmission diagnoses and risk factors for readmission were examined.

RESULTS

We identified 547,068 patients with mean age 74.7 years; 50.7% were female, and 65.4% were White. Of 117,123 patients (21.4%) readmitted within 30 days (median 12 days), 69.7% had a non-heart failure primary readmission diagnosis. Patients with 30-day readmissions more frequently had a history of previous admission with heart failure as a secondary diagnosis, fluid and electrolyte disorders, and chronic deficiency anemia. There were no significant clinical differences at baseline between those patients whose first readmission was in the first 7 days after discharge vs in the next 23 days. The most common primary diagnoses for 30-day non-heart failure readmissions were other cardiovascular conditions (14.9%), pulmonary disease (8.5%), and infections (7.7%).

CONCLUSIONS

In this large all-payer cohort, ∼70% of 30-day readmissions were for non-heart failure causes, and the median time to readmission was 12 days. Future interventions to reduce readmissions should focus on common comorbid conditions that contribute to readmission burden.

BACKGROUND

As pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate and emtricitabine for the prevention of HIV infection is rolled out internationally, strategies to maintain effectiveness and to minimise adverse effects merit consideration. In this study, we aimed to assess reductions in renal function and predictors of renal toxicity in a large open-label study of PrEP.

METHODS

As part of the iPrEx open-label extension (OLE) study, men who have sex with men or transgender women aged 18-70 years who were HIV negative and had participated in three previous PrEP trials from Brazil, Ecuador, Peru, South Africa, Thailand, and the USA were enrolled into an open-label PrEP study. There were no restrictions on current renal function for enrolment into iPrEx OLE, in which participants were given combination tablets of tenofovir disoproxil fumarate (300 mg) and emtricitabine (200 mg) and advised to take one tablet per day. At follow-up sessions every 12 weeks, participants' creatinine clearance on PrEP was estimated and in a subset of participants, hair samples were collected to measure tenofovir and emtricitabine concentrations (a measure of adherence and exposure) via liquid-chromatography-tandem-mass-spectrometry. Reductions in creatinine clearance from baseline were calculated and predictors of decline were identified by use of multivariate models. iPrEx is registered with ClinicalTrials.com, number NCT00458393.

FINDINGS

Baseline characteristics were similar between all participants in iPrEx-OLE (1224 participants with 7475 person-visits) and those participating in the hair substudy (220 participants with 1114 person-visits). During a median of 72 weeks, the mean decline in creatinine clearance was -2·9% (95% CI -2·4 to -3·4; p<0·0001), but declines were greater for those who started PrEP at older ages: participants aged 40-50 years at baseline had declines of -4·2% (95% CI -2·8 to -5·5) and participants older than 50 years at baseline had declines of -4·9% (-3·1 to -6·8). In multivariate models, age and baseline creatinine clearance less than 90 mL/min predicted declines in renal function. We identified a monotonic association between percentage decrease in creatinine clearance and the number of doses of tenofovir disoproxil fumarate and emtricitabine taken per week, as estimated by hair concentrations of tenofovir and emtricitabine (p=0·008).

INTERPRETATION

Our data suggest that the frequency of safety monitoring for PrEP might need to be different between age groups and that pharmacological measures can monitor for toxic effects as well as adherence.

FUNDING

National Institutes of Health.