Seven-year retrospective study understanding the latent TB infection treatment cascade of care among adults in a low incidence country.

BACKGROUND: Prevention of TB is paramount to achieving elimination targets as recommended by the World Health Organization's action framework for low incidence countries striving to eliminate TB. Although the rates of TB in Canada are low, understanding the latent TB infection (LTBI) cascade is paramount to identifying gaps in care and treatment barriers, thereby increasing the effectiveness of preventive strategies. The purpose of this study was to examine the LTBI cascade of care and identify barriers to treatment completion in adults referred from primary care to a regional tertiary care TB clinic in Ottawa, Canada. METHODS: Electronic medical records between January 2010 and December 2016 were reviewed retrospectively and an LTBI cascade of care was constructed from The Ottawa Hospital TB clinic and surrounding primary care clinics. A cohort of 2207 patients with untreated LTBI was used to ascertain the associations between demographic and clinical factors for both treatment non-initiation and non-completion using log-binomial univariable and multivariable regression models. RESULTS: Of 2207 patients with untreated LTBI who were seen in the clinic during the study period, 1771 (80.2%) were offered treatment, 1203 (67.9% of those offered) started treatment, and 795 (66.1% of those started) completed treatment. In multivariable analysis, non-initiation of treatment was associated with older age (adjusted risk ratio [aRR] 1.06 per 5-year increase, 95% CI: 1.03-1.08) and female gender (aRR 1.28, 95% CI: 1.11-1.47). Non completion of treatment was associated with referral from the TB Clinic back to the primary care team following initial consult (aRR 1.62, 95% CI: 1.35-1.94) and treatment with the standard of 9 months of Isoniazid (9H) compared to 4 months of Rifampin (4R) (aRR 1.45, 95% CI:1.20-1.74). CONCLUSIONS: LTBI treatment completion was significantly decreased among patients who were referred back to primary care from the TB clinic. The 4R regimen resulted in more people completing LTBI treatment compared to 9H in keeping with a recently published RCT. Improved education, communication, and collaboration between tertiary care TB clinics and primary care teams may improve treatment completion rates and address the TB burden in low incidence communities in Canada.

A case of relapsed Mycobacterium chelonae pulmonary infection presenting with severe weight loss and treated with a combination of antibiotic therapy and percutaneous feeding.

Mycobacterium chelonae is a type of nontuberculous mycobacteria most commonly associated with skin and soft tissue infections. We present a case of recurrent M. chelonae pulmonary infection presenting with severe weight loss. After recurrence, sputum cultures remained positive for 2 years despite appropriate antibiotics. Cultures only became negative after the addition of intravenous imipenem and jejunostomy feeds. The rarity of M. chelonae pulmonary infection means that optimal treatment regimens have not yet been fully established but a regimen of clarithromycin plus an additional antibiotic has been recommended1. The prognosis of such infections also remains unclear but lower rates of macrolide resistance suggest that the prognosis may be better than the closely related species M. abscessus. Although its benefit has not been proven, nutrition supplementation, including percutaneous enteral feeding, can be considered for refractory NTM infection in underweight patients.

The implementation of rifapentine and isoniazid (3HP) in two remote Arctic communities with a predominantly Inuit population, the Taima TB 3HP study.

Background: The incidence of TB among Inuit is the highest in Canada. A significantly shorter latent TB infection (LTBI) treatment with rifapentine and isoniazid once weekly for 12 weeks (3HP) is now available in limited settings in Canada.Methods: A prospective open-label 2-year observational postmarketing study was conducted introducing 3HP for the first time in Canada in Iqaluit followed by a program rollout in Qikiqtarjuaq, Nunavut.Results: A total of 247 people were offered 3HP, 102 in the Iqaluit postmarketing study and 145 in the Qikiqtarjuaq program roll out. Although statistical significance was not reached, more people who started treatment completed treatment in the 3HP group (Iqaluit, 60/73 (82.2%) and Qikiqtarjuaq, 89/115 (77.4%)) than in the historical control 9INHgroup (306/420 = 72.9%) (p = 0.2). Most of the adverse events in 3HP treated patients were associated with mild discomfort but no disruption of normal daily activity. Not drinking alcohol was associated with increased 3HP completion (OR 13.33, 95% CI, 2.27-78.20) as was not taking concomitant medications (OR 7.19, 95% CI, 1.47-35.30).Conclusions: The present study supports the feasibility and safety profile of 3HP for the treatment of LTBI in Nunavut.

How vision governs the collective behaviour of dense cycling pelotons.

In densely packed groups demonstrating collective behaviour, such as bird flocks, fish schools or packs of bicycle racers (cycling pelotons), information propagates over a network, with individuals sensing and reacting to stimuli over relatively short space and time scales. What remains elusive is a robust, mechanistic understanding of how sensory system properties affect interactions, information propagation and emergent behaviour. Here, we show through direct observation how the spatio-temporal limits of the human visual sensory system govern local interactions and set the network structure in large, dense collections of cyclists. We found that cyclists align in patterns within a ± 30° arc corresponding to the human near-peripheral visual field, in order to safely accommodate motion perturbations. Furthermore, the group structure changes near the end of the race, suggesting a narrowing of the used field of vision. This change is consistent with established theory in psychology linking increased physical exertion to the decreased field of perception. Our results show how vision, modulated by arousal-dependent neurological effects, sets the local arrangement of cyclists, the mechanisms of interaction and the implicit communication across the group. We furthermore describe information propagation phenomena with an analogous elastic solid mechanics model. We anticipate our mechanistic description will enable a more detailed understanding of the interaction principles for collective behaviour in a variety of animals.

On chip quadruplex priming amplification for quantitative isothermal diagnostics.

Nucleic acid testing is a common technique for medical diagnostics. For example, it is used to detect HIV treatment failure by monitoring viral load levels. Quadruplex Priming Amplification (QPA) is an isothermal nucleic acid amplification technique that requires little power and few chemical reagents per assay, all features that make QPA well suited for point-of-care (POC) diagnostics. The QPA assay can be further optimized by integrating it with microfluidic devices that can automate and combine multiple reaction steps and reduce the quantity and cost of reagents per test. In this study, a real-time, exponential QPA reaction is demonstrated for the first time in a microfluidic chip, where the reaction was not inhibited and supported performance levels comparable to a commercially-available, non-microfluidics setup.

A shorter treatment regimen for latent tuberculosis infection holds promise for at-risk Canadians.

Despite recent success in reducing its incidence, tuberculosis remains a considerable challenge in Canada, particularly among foreign-born and Indigenous populations. A key component of the strategy for controlling the disease is the treatment of latent tuberculosis infection. The standard treatment consists of isoniazid (INH) daily for nine months. In recent years, shorter regimens have been developed in the hope of increasing rates of treatment acceptance and completion. Of these, the shortest and most recently developed is a combination of INH and rifapentine taken once weekly for 12 doses (3HP), typically using directly observed therapy (DOT). This regimen has been approved by the Food and Drug Administration in the United States but is not yet authorized in Canada. Based on a rapidly expanding number of observational studies and randomized controlled trials, 12 weeks of 3HP appears to have similar efficacy to nine months of INH, a favourable adverse event profile and potentially improved rates of treatment completion. Although rates of treatment acceptance, the role of self-administered therapy and the regimen's cost-effectiveness within the Canadian context remain uncertain, 3HP is a promising alternative to existing treatments for LTBI.

2015 Recommendations for the management of polymyalgia rheumatica: a European League Against Rheumatism/American College of Rheumatology collaborative initiative

Therapy for polymyalgia rheumatica (PMR) varies widely in clinical practice as international recommendations for PMR treatment are not currently available. In this paper, we report the 2015 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) recommendations for the management of PMR. We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology as a framework for the project. Accordingly, the direction and strength of the recommendations are based on the quality of evidence, the balance between desirable and undesirable effects, patients' and clinicians' values and preferences, and resource use. Eight overarching principles and nine specific recommendations were developed covering several aspects of PMR, including basic and follow-up investigations of patients under treatment, risk factor assessment, medical access for patients and specialist referral, treatment strategies such as initial glucocorticoid (GC) doses and subsequent tapering regimens, use of intramuscular GCs and disease modifying anti-rheumatic drugs (DMARDs), as well as the roles of non-steroidal anti-rheumatic drugs and non-pharmacological interventions. These recommendations will inform primary, secondary and tertiary care physicians about an international consensus on the management of PMR. These recommendations should serve to inform clinicians about best practices in the care of patients with PMR.(AU)

Cardiovascular risk factors in women with primary Sjögren's syndrome: United Kingdom primary Sjögren's syndrome registry results.

OBJECTIVE: To determine the prevalence of traditional cardiovascular risk factors using established definitions in a large cohort of clinically well-characterized primary Sjögren's syndrome (SS) patients and to compare them to healthy controls. METHODS: Data on cardiovascular risk factors in primary SS patients and controls were collected prospectively using a standardized pro forma. Cardiovascular risk factors were defined according to established definitions. The prevalence of cardiovascular risk factors in the primary SS group was determined and compared to that in the control group. RESULTS: Primary SS patients had a higher prevalence of hypertension (28­50% versus 15.5­25.6%; P < 0.01) and hypertriglyceridemia (21% versus 9.5%; P = 0.002) than age- and sex-matched healthy controls. Furthermore, a significant percentage (56%) of hypertensive patients expected to be on antihypertensive treatment according to best practice was not receiving it. CONCLUSION: Primary SS patients are more than 2 times more likely to experience hypertension and hypertriglyceridemia than age- and sex-matched healthy controls. Additionally, hypertension is underdiagnosed and suboptimally treated in primary SS.

Temporal variation in the carrying capacity of a perennial grass population.

Density dependence and, therefore, K (carrying capacity, equilibrium population size) are central to understanding and predicting changes in population size (N). Although resource levels certainly fluctuate, K has almost always been treated as constant in both theoretical and empirical studies. We quantified temporal variation in K by fitting extensions of standard population dynamic models to 16 annual censuses of a population of the perennial bunchgrass Bouteloua rigidiseta. Variable-K models provided substantially better fits to the data than did models that varied the potential rate of population increase. The distribution of estimated values of K was skewed, with a long right tail (i.e., a few "jackpot" years). The population did not track K closely. Relatively slow responses to changes in K combined with large, rapid changes in K sometimes caused N to be far from K. In 13%-20% of annual intervals, K was so much larger than N that the population's dynamics were best described by geometric growth and the population was, in effect, unregulated. Explicitly incorporating temporal variation in K substantially improved the realism of models with little increase in model complexity and provided novel information about this population's dynamics. Similar methods would be applicable to many other data sets.

Polymyalgia rheumatica can be distinguished from late onset rheumatoid arthritis at baseline: results of a 5-yr prospective study.

OBJECTIVE: To describe the pattern of arthropathy and HLA-DRB1 alleles associated with PMR in order to develop a diagnostic algorithm that could help distinguish PMR and RF-negative (RF -ve) late-onset RA (LO-RA) at presentation. METHODS: This was a prospective study of all patients presenting with PMR or LO-RA over a 10-yr period to one physician. Demographic, clinical and laboratory data were collected at presentation and during a minimum of 5 yrs of follow-up. The accuracy of the initial diagnosis was systematically reviewed. RESULTS: One hundred and forty-two patients with LO-RA, 147 with PMR and 42 with PMR + TA were studied. Peripheral synovitis was observed in 23% of the PMR patients. In comparison with RF -ve LO-RA, PMR patients were younger (P < 0.001), myalgia more frequent [100 vs 16% (P < 0.001)] and arthritis of PIP, MCP and wrist were less frequent (P < 0.001). The combination of wrist + MCP/PIP or wrist + PIP + MCP were highly suggestive of RF -ve LO-RA (P < 0.001). HLA-DRB1*0101/0102 and *0401 were significantly increased in PMR patients compared with healthy controls. Plasma viscosity and arthritis in the wrist, in combination with at least one MCP or PIP joint at disease onset, were predictive of whether a non-erosive RF -ve patient would ultimately be diagnosed as having RF -ve LO-RA or PMR (+/-/arthritis). CONCLUSION: Our longitudinal follow-up data were consistent with RF -ve LO-RA being a separate disease entity to PMR despite some phenotypic and immunogenetic similarities at disease onset. A diagnostic algorithm was derived using baseline clinical features to predict the final diagnosis of RF -ve, non-erosive patients.

Reduction of fatigue in Sjögren syndrome with rituximab: results of a randomised, double-blind, placebo-controlled pilot study.

OBJECTIVE: Primary Sjögren syndrome (pSS) causes significant systemic symptoms including fatigue as well as glandular dysfunction. There are currently no effective systemic therapies; however, open label series have suggested that rituximab may be beneficial for systemic and glandular manifestations. Therefore, we performed a double blind, placebo-controlled, randomised pilot study of the efficacy of rituximab in reducing fatigue in pSS. METHODS: A total of 17 patients with pSS and a score on fatigue visual analogue scale (VAS) >50 were randomised to receive either 2 infusions of rituximab 1 g or placebo; patients also received oral and intravenous steroids. Outcome measures included: the proportion of patients with >20% reduction in fatigue VAS, changes in pSS related symptoms, health related quality of life and immunological parameters of pSS. These were measured 6 months after therapy. RESULTS: There was significant improvement from baseline in fatigue VAS in the rituximab group (p<0.001) in contrast to the placebo group (p = 0.147). There was a significant difference between the groups at 6 months in the social functioning score of SF-36 (p = 0.01) and a trend to significant difference in the mental health domain score of SF-36 (p = 0.06). There was one episode of serum sickness in the rituximab treated group. CONCLUSIONS: This is the first double blind study of rituximab in pSS to show benefit; further studies are justified.

Simultaneous sensitivity to fragrances.

BACKGROUND: Cinnamal/cinnamic alcohol and isoeugenol/eugenol are pairs of related fragrance chemicals found in Fragrance Mix I (FM I), and thus are routinely tested in combination with other fragrances in the European standard patch test series. Their close structural similarity makes the occurrence of simultaneous sensitivity within these chemical pairs likely, although at present there are no robust data to support this hypothesis. OBJECTIVES: To establish the frequency of simultaneous reactions to these fragrance chemicals in patients with suspected fragrance allergy attending a contact dermatitis clinic; to provide evidence in support of proposed metabolic pathways; and to determine whether including all four separately in FM I is necessary to avoid missing a diagnosis of fragrance allergy. METHODS: We analysed retrospectively the records of patients patch tested to the European standard series during the 15-year period 1984-98 for positive reactions to FM I. In a subset of patients tested to the constituents of FM I, positive reactions to cinnamal, cinnamic alcohol, isoeugenol and eugenol were sought. Data were analysed using 2x2 contingency tables (Fisher's exact test). RESULTS: During this period, 23,660 patients were tested to the European standard series, of whom 1811 (7.7%) had positive reactions to FM I. Of the 1112 patients tested to the constituents of FM I, 934 had positive reactions to at least one constituent (total 1324 positive reactions to constituents). Of these 934, 826 also had positive reactions to FM I itself; 108 were negative to FM I but reacted to one or more of its constituents. One hundred and seventy-eight patients did not react to any of the breakdown constituents of FM I; 34 of these had positive reactions to FM I itself. Of 139 patients allergic to cinnamic alcohol, 87 were also allergic to cinnamal (63%), compared with 108 (11.1%) of 973 cinnamic alcohol-negative patients (P<0.00001). Of 231 patients allergic to isoeugenol, 50 were also allergic to eugenol (22%), vs. 109 (12.4%) of 881 isoeugenol-negative patients (P=0.0002). CONCLUSIONS: These data support in vitro experiments indicating that cinnamal and cinnamic alcohol may generate a common hapten and are consistent with the view that simultaneous sensitization to isoeugenol and eugenol occurs to a limited extent, despite their being metabolized via different pathways. In view of the substantial number of isolated reactions to each of these fragrance chemicals, all four should continue to be included separately as constituents of FM I.

Differential expression of HOX genes in neoplastic and non-neoplastic human astrocytes.

HOX genes are a large family of regulatory genes implicated in the control of developmental processes. HOX genes are involved in malignant transformation and progression of different types of tumour. Despite intensive efforts to delineate the expression profiles of HOX genes in other cell types, nothing is known regarding the global expression profile of these genes in normal human astrocytes and astrocytomas. The present study has analysed the expression profile of the 39 class I HOX genes in normal human astrocytes (NHA and E6/E7), two well-established glioblastoma cell lines (U-87 MG and U-1242-MG), as well as neoplastic (WHO grades II/III and IV) and non-neoplastic temporal lobe specimens with hippocampal sclerosis and medically intractable epilepsy. RT-PCR, quantitative real-time PCR, immunocytochemistry, and western blot analyses revealed differential expression of nine HOX genes (A6, A7, A9, A13, B13, D4, D9, D10, and D13) in normal human astrocytic cell lines and non-neoplastic temporal lobe specimens. The data show that HOX genes are differentially expressed in neoplastic and non-neoplastic astrocytes and that multiple HOX genes are overexpressed in glioblastoma cell lines, astrocytomas (II/III), and glioblastoma multiforme. The differential expression of HOX genes in normal and neoplastic astrocytes suggests a role for these genes in brain tumourigenesis.

A comparison of the sensitivity of diagnostic criteria for polymyalgia rheumatica.

OBJECTIVE: To compare the performance of the several different diagnostic criteria sets currently in use for polymyalgia rheumatica (PMR). METHODS: 213 patients attending eight rheumatological centres in eight different European countries were studied. All had recently been referred and were considered by the senior investigator at each centre, selected because of their experience in treatment of PMR, to have this condition. By use of a standard international proforma, the requisite diagnostic points in each criteria set were sought. Sensitivity for each criterion from each set was then calculated, as well as the sensitivity of each criteria set as a whole. RESULTS: Of four criteria sets compared, the Bird (1979) criteria performed best with a sensitivity of 99.5%, and the Hunder (1982) criteria second best, with sensitivity of 93.3%. These both performed significantly better than the two other criteria sets, though each of these was admittedly developed for rather specialised reasons. CONCLUSIONS: Although this study compares homogeneity, we suggest the Bird 1979 or Hunder 1982 criteria should be used whenever possible. Studies that have used alternative criteria may have less sensitivity in diagnosis.

Analysis of the insertion/deletion related polymorphism within T cell antigen receptor beta variable genes in primary Sjögren's syndrome.

OBJECTIVE: To analyse T cell receptor beta variable (TCRBV) gene polymorphisms (insertion/deletion related polymorphism (IDRP) and BV6S7) in primary Sjögren's syndrome (PSS). METHODS: Genomic DNA was extracted from blood samples from patients fulfilling the modified European criteria for PSS (n = 61). Healthy control blood samples were obtained from the Blood Transfusion Service (n = 121). As a disease control group, samples from patients with systemic lupus erythematosus (n = 42) were analysed. BV6S7 was genotyped using an established PCR/RFLP method. The IDRP was determined by comparison of the intensity of PCR product bands from within BV9S2 and an internal control region (BV9S1), to ascertain whether 0, 1, or 2 copies of the insertion were present. RESULTS: There was a decrease (p = 0.018) in the proportion of PSS patients with the deleted/deleted genotype. There was no association with specific BV6S7 alleles or genotypes with either the PSS group or the hypergammaglobulinaemic subgroup. There were no significant differences in haplotype frequencies after Bonferroni correction. CONCLUSIONS: A reduced proportion of patients with PSS have the deleted/deleted genotype. Eighty nine per cent of PSS patients have at least one extra germline copy of BV13S2*1. This may relate to previous observations of increased BV13 specific T cells and mRNA in the salivary glands.

Contact allergy: the role of skin chemistry and metabolism.

Chemical reactivity plays the driving role in the biological processes that result in the induction of allergic contact dermatitis. This paper presents an overview of the chemical basis of allergic contact dermatitis, including the physicochemical parameters governing skin penetration, chemical reaction mechanisms associated with haptenation of skin proteins, (quantitative) structure-activity relationships (Q)SARs for contact allergens and prohaptens/skin metabolism of contact allergens. Despite the complexities and poor understanding of some of the metabolic processes leading to skin sensitization, it is possible to describe some of the relationships between chemical structures and the ability to form covalent conjugates with proteins. This knowledge, which relates chemical structure to a specific endpoint, can be programmed into an expert system. The Deductive Estimation of Risk from Existing Knowledge (DEREK) is one such expert system which is described in further detail.

Contact allergy: the local lymph node assay for the prediction of hazard and risk.

The prospective identification of potential contact allergens and their subsequent safety assessment are pivotal in successful management of this risk to human health. Although much can be learned from the chemical and physical properties of a substance, the definitive information in respect of sensitizing hazard/risk derives from an assessment of the integrated response of the immune system. In recent years, the focus for such assessments has begun to switch from the guinea pig to the mouse, notably to the local lymph node assay (LLNA). In this paper, the current value of the LLNA for hazard identification is reviewed and its regulatory status defined. Once a potential contact allergen has been identified, however, the vital clue to accurate safety evaluation is the assessment of the potency of the allergen. How this can be achieved using the LLNA and employed in safety evaluation is discussed in detail, together with practical suggestions for the deployment of such processes in regulatory toxicology.

FcgammaRIIIA-158V and rheumatoid arthritis: a confirmation study.

OBJECTIVES: To develop a robust assay for genotyping the FcgammaRIIIA-158V/F polymorphism and to confirm the putative association between the FcgammaRIIIA-158V allele and rheumatoid arthritis (RA). METHODS: This allelic association study examined the FcgammaRIIIA-158V/F polymorphism for association with RA. A novel single-stranded conformational polymorphism assay was used to genotype 828 RA patients and 581 controls from the UK. RESULTS: The FcgammaRIIIA-158V allele was associated with both RA (P=0.02) and nodules (P=0.04). Individuals homozygous for this higher affinity allele had a significantly increased risk of RA (OR 1.53, 95% CI 1.08-2.18) and the development of nodules (OR 2.20, 95% CI 1.20-4.01). There was no evidence of an interaction with the shared epitope. CONCLUSIONS: We have developed a novel assay to genotype the FcgammaRIIIA-158F/V polymorphism and confirmed that homozygosity for the FcgammaRIIIA-158V allele is associated with UK Caucasian RA, particularly in those individuals with nodules, suggesting FcgammaRIIIA may play a role in determining disease severity or in the development of nodules per se.

Structure-activity relationships for selected fragrance allergens.

Fragrance substances represent a very diverse group of chemicals, a proportion of them providing not only desirable aroma characteristics, but also being associated with adverse effects, notably the ability to cause allergic reactions in the skin. However, efforts to find substitute materials are hampered by the need to undertake animal testing to evaluate both the presence and the degree of skin sensitization hazard. One potential route to avoid such testing is to understand the relationships between chemical structure and skin sensitization. In the present work we have evaluated two groups of fragrance chemicals, saturated aldehydes (aryl substituted and aliphatic aldehydes) and alpha,beta-unsaturated aldehydes. Data on their skin sensitization potency defined using the local lymph node assay has been evaluated in relation to their physicochemical properties. The initial outcome has been consistent with the concept that alpha,beta-unsaturated aldehydes react largely via Michael addition, whilst the group of saturated aldehydes form Schiff bases with proteins. Simple models of chemical reactivity based on these mechanisms suggest that it may be possible to predict allergenic potency. Accordingly, the evaluation of an additional group of similar aldehydes is now underway to assess the robustness of these models, with some emphasis being based on ensuring a wider spread of chemical reactivity.