The use of hand grip strength as a predictor of nutrition status in hospital patients.

BACKGROUND & AIMS: Hand grip strength (HGS) has been found to respond to nutrition deprivation and repletion but few studies have investigated its use as an independent nutrition assessment tool. We conducted an observational study to determine if HGS can predict nutrition status independently of other factors. METHODS: The Patient Generated Subjective Global Assessment (PG-SGA) was used to determine nutrition status. PG-SGA and HGS measures were collected from 217 well nourished and malnourished hospital patients for cross-sectional analysis. Of the 217, 18 patients had these assessments repeated two weeks (±3 days) later to assess change. Correlation, and multiple linear and binary regression analyses were conducted. RESULTS: HGS and PG-SGA score were significantly correlated (r = 0.292, P < 0.01). HGS was a significant independent predictor of PG-SGA score and category (P < 0.01), accounting for 4% and 9% of variability respectively. Change-in-HGS was an independent predictor of change-in-PG-SGA score (P = 0.04) and category (P = 0.06) over two weeks, accounting for 47% and 42% of variability respectively. CONCLUSIONS: Our results suggest that HGS can independently predict nutrition status and change in nutrition status defined by PG-SGA score and category, although future longer term research is required to confirm the use of HGS as an early detection tool for malnutrition risk.

The role of IL-15 deficiency in the pathogenesis of virus-induced asthma exacerbations.

Rhinovirus infections are the major cause of asthma exacerbations. We hypothesised that IL-15, a cytokine implicated in innate and acquired antiviral immunity, may be deficient in asthma and important in the pathogenesis of asthma exacerbations. We investigated regulation of IL-15 induction by rhinovirus in human macrophages in vitro, IL-15 levels in bronchoalveolar lavage (BAL) fluid and IL-15 induction by rhinovirus in BAL macrophages from asthmatic and control subjects, and related these to outcomes of infection in vivo. Rhinovirus induced IL-15 in macrophages was replication-, NF-κB- and α/ß interferon-dependent. BAL macrophage IL-15 induction by rhinovirus was impaired in asthmatics and inversely related to lower respiratory symptom severity during experimental rhinovirus infection. IL-15 levels in BAL fluid were also decreased in asthmatics and inversely related with airway hyperresponsiveness and with virus load during in vivo rhinovirus infection. Deficient IL-15 production in asthma may be important in the pathogenesis of asthma exacerbations.

Rhinovirus-induced lower respiratory illness is increased in asthma and related to virus load and Th1/2 cytokine and IL-10 production.

Acute exacerbations are the major cause of asthma morbidity, mortality, and health-care costs and are difficult to treat and prevent. The majority of asthma exacerbations are associated with rhinovirus (RV) infection, but evidence supporting a causal relationship is weak and mechanisms are poorly understood. We hypothesized that in asthmatic, but not normal, subjects RV infection would induce clinical, physiologic, and pathologic lower airway responses typical of an asthma exacerbation and that these changes would be related to virus replication and impaired T helper 1 (Th1)/IL-10 or augmented Th2 immune responses. We investigated physiologic, virologic, and immunopathologic responses to experimental RV infection in blood, induced sputum, and bronchial lavage in 10 asthmatic and 15 normal volunteers. RV infection induced significantly greater lower respiratory symptoms and lung function impairment and increases in bronchial hyperreactivity and eosinophilic lower airway inflammation in asthmatic compared with normal subjects. In asthmatic, but not normal, subjects virus load was significantly related to lower respiratory symptoms, bronchial hyperreactivity, and reductions in blood total and CD8(+) lymphocytes; lung function impairment was significantly related to neutrophilic and eosinophilic lower airway inflammation. The same virologic and clinical outcomes were strongly related to deficient IFN-gamma and IL-10 responses and to augmented IL-4, IL-5, and IL-13 responses. This study demonstrates increased RV-induced clinical illness severity in asthmatic compared with normal subjects, provides evidence of strong relationships between virus load, lower airway virus-induced inflammation and asthma exacerbation severity, and indicates augmented Th2 or impaired Th1 or IL-10 immunity are likely important mechanisms.

An experimental model of rhinovirus induced chronic obstructive pulmonary disease exacerbations: a pilot study.

BACKGROUND: Acute exacerbations of COPD are a major cause of morbidity, mortality and hospitalisation. Respiratory viruses are associated with the majority of exacerbations but a causal relationship has not been demonstrated and the mechanisms of virus-induced exacerbations are poorly understood. Development of a human experimental model would provide evidence of causation and would greatly facilitate understanding mechanisms, but no such model exists. METHODS: We aimed to evaluate the feasibility of developing an experimental model of rhinovirus induced COPD exacerbations and to assess safety of rhinovirus infection in COPD patients. We carried out a pilot virus dose escalating study to assess the minimum dose of rhinovirus 16 required to induce experimental rhinovirus infection in subjects with COPD (GOLD stage II). Outcomes were assessed by monitoring of upper and lower respiratory tract symptoms, lung function, and virus replication and inflammatory responses in nasal lavage. RESULTS: All 4 subjects developed symptomatic colds with the lowest dose of virus tested, associated with evidence of viral replication and increased pro-inflammatory cytokines in nasal lavage. These were accompanied by significant increases in lower respiratory tract symptoms and reductions in PEF and FEV1. There were no severe exacerbations or other adverse events. CONCLUSION: Low dose experimental rhinovirus infection in patients with COPD induces symptoms and lung function changes typical of an acute exacerbation of COPD, appears safe, and provides preliminary evidence of causation.

Role of deficient type III interferon-lambda production in asthma exacerbations.

Rhinoviruses are the major cause of asthma exacerbations, and asthmatics have increased susceptibility to rhinovirus and risk of invasive bacterial infections. Here we show deficient induction of interferon-lambdas by rhinovirus in asthmatic primary bronchial epithelial cells and alveolar macrophages, which was highly correlated with severity of rhinovirus-induced asthma exacerbation and virus load in experimentally infected human volunteers. Induction by lipopolysaccharide in asthmatic macrophages was also deficient and correlated with exacerbation severity. These results identify previously unknown mechanisms of susceptibility to infection in asthma and suggest new approaches to prevention and/or treatment of asthma exacerbations.

Emergence of resistance to protease inhibitor amprenavir in human immunodeficiency virus type 1-infected patients: selection of four alternative viral protease genotypes and influence of viral susceptibility to coadministered reverse transcriptase nucleoside inhibitors.

Previous data have indicated that the development of resistance to amprenavir, an inhibitor of the human immunodeficiency virus type 1 protease, is associated with the substitution of valine for isoleucine at residue 50 (I50V) in the viral protease. We present further findings from retrospective genotypic and phenotypic analyses of plasma samples from protease inhibitor-naïve and nucleoside reverse transcriptase inhibitor (NRTI)-experienced patients who experienced virological failure while participating in a clinical trial where they had been randomized to receive either amprenavir or indinavir in combination with NRTIs. Paired baseline and on-therapy isolates from 31 of 48 (65%) amprenavir-treated patients analyzed demonstrated the selection of protease mutations. These mutations fell into four distinct categories, characterized by the presence of either I50V, I54L/I54M, I84V, or V32I+I47V and often included accessory mutations, commonly M46I/L. The I50V and I84V genotypes displayed the greatest reductions in susceptibility to amprenavir, although each of the amprenavir-selected genotypes conferred little or no cross-resistance to other protease inhibitors. There was a significant association, for both amprenavir and indinavir, between preexisting baseline resistance to NRTIs subsequently received during the study and development of protease mutations (P = 0.014 and P = 0.031, respectively). Our data provide a comprehensive analysis of the mechanisms by which amprenavir resistance develops during clinical use and present evidence that resistance to concomitant agents in the treatment regimen predisposes to the development of mutations associated with protease inhibitor resistance and treatment failure.

Human hepatic glyceraldehyde-3-phosphate dehydrogenase binds to the poly(U) tract of the 3' non-coding region of hepatitis C virus genomic RNA.

The unique poly(U/UC) tract, the middle part of the tripartite 3' non-coding region (3'NCR) of hepatitis C virus (HCV) genomic RNA, may represent a recognition signal for the HCV replicase complex. In this study, several proteins binding specifically to immobilized ribooligonucleotide r(U)(25) mimicking this structure were identified using cytosolic extracts from HCV-negative or -positive liver explants, and a prominent 36 kDa protein was studied further. Competition experiments including homoribopolymers revealed binding affinities in the order: oligo/poly(U)>(A)>(C)>(G). The protein was identified as glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a multifunctional protein known to bind RNA. GAPDH bound efficiently to the full-length HCV RNA and binding to various 3'NCR constructs revealed critical dependence upon the presence of the middle part of the 3'NCR. Polypyrimidine tract-binding protein, described previously to bind the 3'NCR, did not bind efficiently to the middle part of 3'NCR and was captured from liver extracts in considerably smaller quantities.