The Identification and Cost of Acute Chronic Obstructive Pulmonary Disease Exacerbations in a United States Population Healthcare Claims Database.

Almost half of chronic obstructive pulmonary disease (COPD) exacerbations are estimated to be inaccurately reported by patients, inconsistently recorded in medical records, or not measured due to coding errors inherent to administrative claims. This retrospective observational study aimed to develop an algorithm capable of detecting acute COPD exacerbations (AECOPD) in healthcare claims and estimate costs associated with AECOPD over a 12-month period. Commercial and Medicare Advantage healthcare plan members (≥40 years old) with evidence of COPD were identified from US healthcare-claims database. To refine the algorithm detecting AECOPD in claims data, sensitivity and positive-predictive value calculations were performed to compare AECOPD identification in healthcare claims versus medical charts. Analyses were also performed to examine total exacerbation-related costs for events identified with the new claims algorithm plus events missed. The final algorithm had a sensitivity of 84.9%, with a positive-predictive value of 67.5%. Medical records were abstracted for 402 patients. In the overall sample of healthcare claims (n = 243,998), the algorithm detected ≥1 AECOPD event in 61.3% of patients. The mean cost per patient during an AECOPD episode, identified by the final algorithm, was USD 6,760 (n = 301), with an incremental average cost of USD 607 (n = 122) to 'unobserved' episodes (not reported in claims data) among the chart sample. After multivariate modeling, predicted yearly exacerbation costs translated to USD 1.12 billion per 100,000 patients (USD 12,000 per patient), with 35.76 million associated with unobserved exacerbations. While the final algorithm warrants further validation and study, these findings highlight unobserved AECOPD and their economic burden.

Code-assisted discovery of TAL effector targets in bacterial leaf streak of rice reveals contrast with bacterial blight and a novel susceptibility gene.

Bacterial leaf streak of rice, caused by Xanthomonas oryzae pv. oryzicola (Xoc) is an increasingly important yield constraint in this staple crop. A mesophyll colonizer, Xoc differs from X. oryzae pv. oryzae (Xoo), which invades xylem to cause bacterial blight of rice. Both produce multiple distinct TAL effectors, type III-delivered proteins that transactivate effector-specific host genes. A TAL effector finds its target(s) via a partially degenerate code whereby the modular effector amino acid sequence identifies nucleotide sequences to which the protein binds. Virulence contributions of some Xoo TAL effectors have been shown, and their relevant targets, susceptibility (S) genes, identified, but the role of TAL effectors in leaf streak is uncharacterized. We used host transcript profiling to compare leaf streak to blight and to probe functions of Xoc TAL effectors. We found that Xoc and Xoo induce almost completely different host transcriptional changes. Roughly one in three genes upregulated by the pathogens is preceded by a candidate TAL effector binding element. Experimental analysis of the 44 such genes predicted to be Xoc TAL effector targets verified nearly half, and identified most others as false predictions. None of the Xoc targets is a known bacterial blight S gene. Mutational analysis revealed that Tal2g, which activates two genes, contributes to lesion expansion and bacterial exudation. Use of designer TAL effectors discriminated a sulfate transporter gene as the S gene. Across all targets, basal expression tended to be higher than genome-average, and induction moderate. Finally, machine learning applied to real vs. falsely predicted targets yielded a classifier that recalled 92% of the real targets with 88% precision, providing a tool for better target prediction in the future. Our study expands the number of known TAL effector targets, identifies a new class of S gene, and improves our ability to predict functional targeting.

Treatment adherence, clinical outcomes, and economics of triple-drug therapy in hypertensive patients.

Poor antihypertensive treatment adherence adversely affects blood pressure control. We analyzed US health plan data to assess the impact of fixed- versus loose-dose triple-combination therapy on adherence, clinical, and economic outcomes. Patients initiating triple therapy with an angiotensin receptor blocker, angiotensin-converting enzyme inhibitor, or beta blocker plus amlodipine and hydrochlorothiazide comprised three cohorts. Within-cohort comparisons were made between fixed-dose combinations of two antihypertensives plus a second pill (two pills) or three separate pills. Outcomes included adherence, cardiovascular events, health care resource use, and costs for patients with ≥ 12 months follow-up. A total of 16,290 patients were matched. Patients receiving two pills were more likely to be adherent (P < .001) and less likely to discontinue treatment (P < .001) across all cohorts. Therapy with two versus three pills resulted in significantly lower adjusted risk of cardiovascular events (hazard ratio = 0.76, P = .005) in the beta blocker cohort only. Total adjusted health care costs were significantly lower for two- versus three-pill therapy in the beta blocker cohort only (cost ratio = 0.74 overall, P < .01; 0.71 hypertension-attributable, P < .01). In patients with hypertension requiring triple therapy, fixed-dose combinations that lower pill burden may improve adherence (seen across all cohorts) and clinical outcomes (seen in the beta blocker cohort) without increasing health care costs.

Transcriptome analyses and virus induced gene silencing identify genes in the Rpp4-mediated Asian soybean rust resistance pathway.

Rpp4 (Resistance to Phakopsora pachyrhizi 4) confers resistance to Phakopsora pachyrhizi Sydow, the causal agent of Asian soybean rust (ASR). By combining expression profiling and virus induced gene silencing (VIGS), we are developing a genetic framework for Rpp4-mediated resistance. We measured gene expression in mock-inoculated and P. pachyrhizi-infected leaves of resistant soybean accession PI459025B (Rpp4) and the susceptible cultivar (Williams 82) across a 12-day time course. Unexpectedly, two biphasic responses were identified. In the incompatible reaction, genes induced at 12h after infection (hai) were not differentially expressed at 24 hai, but were induced at 72 hai. In contrast, genes repressed at 12 hai were not differentially expressed from 24 to 144 hai, but were repressed 216 hai and later. To differentiate between basal and resistance-gene (R-gene) mediated defence responses, we compared gene expression in Rpp4-silenced and empty vector-treated PI459025B plants 14 days after infection (dai) with P. pachyrhizi. This identified genes, including transcription factors, whose differential expression is dependent upon Rpp4. To identify differentially expressed genes conserved across multiple P. pachyrhizi resistance pathways, Rpp4 expression datasets were compared with microarray data previously generated for Rpp2 and Rpp3-mediated defence responses. Fourteen transcription factors common to all resistant and susceptible responses were identified, as well as fourteen transcription factors unique to R-gene-mediated resistance responses. These genes are targets for future P. pachyrhizi resistance research.

Biphasic gene expression changes elicited by Phakopsora pachyrhizi in soybean correlate with fungal penetration and haustoria formation.

Inoculation of soybean (Glycine max) plants with Phakopsora pachyrhizi, the causal organism of Asian soybean rust, elicits a biphasic response characterized by a burst of differential gene expression in the first 12 h. A quiescent period occurs from 24 to 48 h after inoculation, in which P. pachyrhizi continues to develop but does not elicit strong host responses, followed by a second phase of intense gene expression. To correlate soybean responses with P. pachyrhizi growth and development, we inoculated the soybean cultivar Ankur (accession PI462312), which carries the Rpp3 resistance gene, with avirulent and virulent isolates of P. pachyrhizi. The avirulent isolate Hawaii 94-1 elicits hypersensitive cell death that limits fungal growth on Ankur and results in an incompatible response, while the virulent isolate Taiwan 80-2 grows extensively, sporulates profusely, and produces a compatible reaction. Inoculated leaves were collected over a 288-h time course for microarray analysis of soybean gene expression and microscopic analysis of P. pachyrhizi growth and development. The first burst in gene expression correlated with appressorium formation and penetration of epidermal cells, while the second burst of gene expression changes followed the onset of haustoria formation in both compatible and incompatible interactions. The proliferation of haustoria coincided with the inhibition of P. pachyrhizi growth in the incompatible interaction or the beginning of accelerated growth in the compatible interaction. The temporal relationships between P. pachyrhizi growth and host responses provide an important context in which to view interacting gene networks that mediate the outcomes of their interactions.