Publications

INTRODUCTION

Elevated lipoprotein(a) (Lp(a)) levels were reported to be associated with dense fibrin clots. The apo(a) component of Lp(a) is encoded by LPA, and the Met allele of the LPA Ile4399Met polymorphism is associated with elevated Lp(a) levels and cardiovascular disease risk. We investigated whether Ile4399Met was associated with fibrin clot properties.

MATERIALS AND METHODS

We determined plasma Lp(a) levels, fibrin clot permeability and lysis time for 64 LPA 4399Met carriers and 128 noncarriers matched for age, sex, ethnicity, and enrollment site.

RESULTS

Elevated Lp(a) levels were associated with reduced clot permeability and prolonged lysis time (P<0.0001). Carriers of 4399Met had higher Lp(a) levels compared with noncarriers (P=0.0003). However, this association differed by ethnicity (P=0.003 for interaction between genotype and ethnicity): compared with noncarriers, 4399Met carriers had 2.89 fold higher Lp(a) levels among Caucasians while no difference was observed among non-Caucasians (primarily East Asians and Hispanics). Among all subjects, no association was observed between Ile4399Met and clot properties, but this relationship also differed by ethnicity: among non-Caucasians, 4399Met carriers had increased clot permeability and shorter lysis time; whereas among Caucasians, the trend was for decreased permeability and longer lysis time (P<0.01 for interactions between genotype and ethnicity).

CONCLUSIONS

We confirmed that elevated Lp(a) levels are associated with dense fibrin clots, and found that the association of LPA 4399Met carriers and clot permeability as well as lysis time differ by ethnicity.

The maintenance of immunological tolerance requires the deletion of self-reactive T cells in the thymus. The expression of genes encoding tissue-specific antigens (TSAs) by thymic epithelial cells is critical for this process and depends on activity of the transcriptional regulator Aire; however, the molecular mechanisms Aire uses to target loci encoding TSAs are unknown. Here we identified two Aire-interacting proteins known to be involved in gene repression, ATF7ip and MBD1, that were required for Aire's targeting of loci encoding TSAs. Moreover, Mbd1(-/-) mice developed pathological autoimmunity and had a defect in Aire-dependent thymic expression of genes encoding TSAs, which underscores the importance of Aire's interaction with the ATF7ip-MBD1 protein complex in maintaining central tolerance.

BACKGROUND AND OBJECTIVE

In low and middle-income countries where HIV infection is prevalent, identifying patients at high risk of dying from lower respiratory tract infections is challenging and validated prognostic models are lacking. Serum procalcitonin may be a useful prognostic tool in these settings. We sought to determine if elevated serum procalcitonin is associated with increased in-hospital mortality and to combine serum procalcitonin with available clinical characteristics to create a clinically useful prognostic model.

METHODS

We conducted a prospective, nested case-control study of 241 HIV-infected adults admitted to Mulago Hospital in Kampala, Uganda with cough ≥2 weeks in duration. We collected demographic and clinical information, baseline serum for procalcitonin analysis, and followed patients to determine in-hospital mortality.

RESULTS

Serum procalcitonin was a strong and independent predictor of inpatient mortality (aOR = 7.69, p = 0.01, sensitivity = 93%, negative predictive value = 97%). Best subset multivariate analysis identified 3 variables that were combined into a prognostic model to risk stratify patients; these variables included respiratory rate ≥30 breaths/minute (aOR = 2.07, p = 0.11), oxygen saturation <90% (aOR = 3.07, p = 0.02), and serum procalcitonin >0.5 ng/ml (aOR = 7.69, p = 0.01). The predicted probability of inpatient mortality ranged from 1% when no variables were present, to 42% when all variables were present.

CONCLUSIONS

Elevated serum procalcitonin >0.5 ng/ml is an independent predictor of in-hospital mortality. Elevated serum procalcitonin, tachypnea, and hypoxemia may be combined into a prognostic model to identify patients at high risk of dying in the hospital. This model may be used to estimate the probability of death and to guide triage and treatment decisions.

OBJECTIVES

This analysis aimed to perform a head-to-head comparison of 3 of the promising biomarkers of cardiovascular (CV) outcomes in heart failure (HF)-soluble ST2 (sST2), growth differentiation factor (GDF)-15, and highly-sensitive troponin T (hsTnT)-and to evaluate the role of serial measurement of these biomarkers in patients with chronic HF.

BACKGROUND

sST2, GDF-15, and hsTnT are strongly associated with CV outcomes in HF.

METHODS

This post-hoc analysis used data from a study in which 151 patients with chronic HF due to left ventricular systolic dysfunction were followed up over 10 months. At each visit, N-terminal pro-B-type natriuretic peptide (NT-proBNP), sST2, GDF-15, and hsTnT were measured and any major CV events were recorded.

RESULTS

Baseline values of all 3 novel biomarkers independently predicted total CV events even after adjusting for clinical and biochemical characteristics, including NT-proBNP, with the best model including all 3 biomarkers (p < 0.001). Adding serial measurement to the base model appeared to improve the model's predictive ability (with sST2 showing the most promise), but it is not clear whether this addition is a unique contribution. However, when time-dependent factors were included, only sST2 serial measurement independently added to the risk model (odds ratio: 3.64; 95% confidence interval: 1.37 to 9.67; p = 0.009) and predicted reverse myocardial remodeling (odds ratio: 1.22; 95% confidence interval: 1.04 to 1.43; p = 0.01).

CONCLUSIONS

In patients with chronic HF, baseline measurement of novel biomarkers added independent prognostic information to clinical variables and NT-proBNP. Only serial measurement of sST2 appeared to add prognostic information to baseline concentrations and predicted change in left ventricular function. (Use of NT-proBNP Testing to Guide Heart Failure Therapy in the Outpatient Setting (PROTECT)]; NCT00351390).

OBJECTIVE

Documentation of quality measures (QMs) in rheumatoid arthritis (RA) is used as a surrogate for measure of quality of care, but the association of this documentation with radiographic outcomes is uncertain. We examined documentation of RA QMs, for disease activity and functional status and the association with radiographic outcomes.

METHODS

Data were analyzed for 438 RA patients in a longitudinal cohort with complete data on van der Heijde-modified Total Sharp Score (TSS). All rheumatologist (N = 18) notes in the electronic medical record during a 24-month period were reviewed for RA QMs. Any mention of disease activity categorized as low, moderate, or high was considered documentation of the QM for disease activity. Functional status QM documentation included any mention of the impact of RA on function. Change in TSS was quantified with progression defined as ≥1 unit per year. We compared percent of visits with an RA QM documented and mean change in TSS.

RESULTS

The mean age in the cohort was 56.9 years, disease duration was 10.8 years, baseline DAS28 score was 3.8 (±1.6), 67.7% were seropositive, and 33.9% used a biologic DMARD. Radiographic progression was observed in 28.5%. Disease activity was documented for 29.0% of patient visits and functional status in 74.7%; neither had any significant relationship to mean TSS change (both P > 0.10).

CONCLUSION

The documentation of RA QMs was infrequent and not associated with radiographic outcomes over 24 months.

BACKGROUND

Risk behaviors among female sex workers (FSW) are considerable drivers of HIV infections in Vietnam, especially transmission between high-risk and low-risk groups. We assessed HIV prevalence and its correlates among FSWs, and the use of preventive services among this community in the Mekong Delta region, southern Vietnam.

METHODS

A cross-sectional survey of 1,999 FSWs was carried out in five provinces including Ben Tre, Hau Giang, Kien Giang, Tien Giang, and Vinh Long between June, 2006 and June, 2007. We interviewed participants face-to-face in order to elicit information about their lives and potential risk factors, and we tested their sera to determine their HIV status. We then performed multivariate logistic regression analyses to investigate factors associated with HIV infection.

RESULTS

Seventeen percent of the participating FSWs were street-based sex workers (SSWs) and the rest (83%) were entertainment establishment-based sex workers (ESWs). Unprotected sex with regular and casual clients in the past month was frequent among study participants (40.5% and 33.5% respectively). However, few respondents (1.3%) had ever injected drugs. Only 2.1% (95% confidence interval (CI): 1.6%-2.8%) of FSWs were found to be infected with HIV. HIV prevalence among SSWs was greater than among ESWs (3.8% vs. 1.8%, p = 0.02, respectively). Increased risk for HIV infection was significantly associated with the number of clients per month (adjusted odd ratio (aOR) = 2.65, 95% CI: 1.26-5.59).

CONCLUSIONS

Interventions to reduce unsafe sex and drug injection, and to increase uptake of HIV testing among FSWs are necessary. Differences in HIV prevalence and its correlates by type of sex work emphasize the importance of constrained contexts in shaping risk behaviors among FSWs; that should be considered in designing HIV prevention programs.