Clinical case: Differential diagnosis of idiopathic pulmonary fibrosis

Background

The diagnosis of idiopathic pulmonary fibrosis can be quite challenging, even after careful clinical evaluation, imaging and pathological tests. This case report intends to demonstrate and discuss these difficulties, especially those concerning the differential diagnosis with chronic hypersensitivity pneumonitis.

Case presentation

A 58-year-old white male presented with shortness of breath, dry cough, fatigue and weight loss for two months. He was a former smoker and had regular exposure to a parakeet and poultry. Physical examination revealed bilateral basal crackles and chest imaging showed subpleural cystic lesions and traction bronchiectasis with a right side and upper level predominance. Auto-antibodies and IgG immunoglobulins to parakeet and fungal proteins were negative. Lung function tests displayed moderate restriction, low diffusion capacity and resting hypoxaemia. Bronchoalveolar lavage showed increased lymphocytes (28%) and neutrophils (12%) and surgical lung biopsy was compatible with a pattern of usual interstitial pneumonia. According to the possibility of either idiopathic pulmonary fibrosis or chronic hypersensitivity pneumonitis, treatment included prednisolone, azathioprine, acetylcysteine and avoidance of contact with the parakeet, but there was an unfavorable response and the patient was subsequently referred for lung transplant.

Conclusion

Chronic hypersensitivity pneumonitis and idiopathic pulmonary fibrosis can present with the same clinical and radiological manifestations In this case, despite careful evaluation, no definite diagnosis could be achieved.

     

Food Insecurity,Food Based Coping Strategies and Suboptimal Dietary Practices of Adolescents in Jimma Zone Southwest Ethiopia

Despite the high prevalence of adolescent food insecurity in Ethiopia, there is no study which documented its association with suboptimal dietary practices. The objective of this study is to determine the association between adolescent food insecurity and dietary practices. We used data on 2084 adolescents in the age group of 13–17 years involved in the first round survey of the five year longitudinal family study in Southwest Ethiopia. Adolescents were selected using residence stratified random sampling methods. Food insecurity was measured using scales validated in developing countries. Dietary practices were measured using dietary diversity score, food variety score and frequency of consuming animal source food. Multivariable regression models were used to compare dietary behaviors by food security status after controlling for socio-demographic and economic covariates.Food insecure adolescents had low dietary diversity score (P<0.001), low mean food variety score (P<0.001) and low frequency of consuming animal source foods (P<0.001). After adjusting for other variables in a multivariable logistic regression model, adolescent food insecurity (P<0.001) and rural residence (P<0.001) were negatively associated with the likelihood of having a diversified diet (P<0.001) and frequency of consuming animal source foods, while a high household income tertile was positively associated. Similarly, multivariable linear regression model showed that adolescent food insecurity was negatively associated with food variety score, while residence in semi-urban areas (P<0.001), in urban areas (P<0.001) and high household income tertile (P = 0.013) were positively associated. Girls were less likely to have diversified diet (P = 0.001) compared with boys.Our findings suggest that food insecurity has negative consequence on optimal dietary intake of adolescents. Food security interventions should look into ways of targeting adolescents to mitigate these dietary consequences and provide alternative strategies to improve dietary quality of adolescents in Southwest Ethiopia.     

Omega 3 Fatty Acids Promote Macrophage Reverse Cholesterol Transport in Hamster Fed High Fat Diet

The aim of this study was to investigate macrophage reverse cholesterol transport (RCT) in hamster, a CETP-expressing species, fed omega 3 fatty acids (ω3PUFA) supplemented high fat diet (HFD). Three groups of hamsters (n = 6/group) were studied for 20 weeks: 1) control diet: Control, 2) HFD group: HF and 3) HFD group supplemented with ω3PUFA (EPA and DHA): HFω3. In vivo macrophage-to-feces RCT was assessed after an intraperitoneal injection of ³H-cholesterol-labelled hamster primary macrophages.Compared to Control, HF presented significant (p<0.05) increase in body weight, plasma TG (p<0.01) and cholesterol (p<0.001) with an increase in VLDL TG and in VLDL and LDL cholesterol (p<0.001).Compared to HF, HFω3 presented significant decrease in body weight. HFω3 showed less plasma TG (p<0.001) and cholesterol (p<0.001) related to a decrease in VLDL TG and HDL cholesterol respectively and higher LCAT activity (p<0.05) compared to HF. HFω3 showed a higher fecal bile acid excretion (p<0.05) compared to Control and HF groups and higher fecal cholesterol excretion (p<0.05) compared to HF. This increase was related to higher gene expression of ABCG5, ABCA1 and SR-B1 in HFω3 compared to Control and HF groups (<0.05) and in ABCG1 and CYP7A1 compared to HF group (p<0.05). A higher plasma efflux capacity was also measured in HFω3 using ³H- cholesterol labeled Fu5AH cells.In conclusion, EPA and DHA supplementation improved macrophage to feces reverse cholesterol transport in hamster fed HFD. This change was related to the higher cholesterol and fecal bile acids excretion and to the activation of major genes involved in RCT.     

Multiple Single-Cell Genomes Provide Insight into Functions of Uncultured Deltaproteobacteria in the Human Oral Cavity

Despite a long history of investigation, many bacteria associated with the human oral cavity have yet to be cultured. Studies that correlate the presence or abundance of uncultured species with oral health or disease highlight the importance of these community members. Thus, we sequenced several single-cell genomic amplicons from Desulfobulbus and Desulfovibrio (class Deltaproteobacteria) to better understand their function within the human oral community and their association with periodontitis, as well as other systemic diseases. Genomic data from oral Desulfobulbus and Desulfovibrio species were compared to other available deltaproteobacterial genomes, including from a subset of host-associated species. While both groups share a large number of genes with other environmental Deltaproteobacteria genomes, they encode a wide array of unique genes that appear to function in survival in a host environment. Many of these genes are similar to virulence and host adaptation factors of known human pathogens, suggesting that the oral Deltaproteobacteria have the potential to play a role in the etiology of periodontal disease.     

MTHFR Glu429Ala and ERCC5 His46His Polymorphisms Are Associated with Prognosis in Colorectal Cancer Patients: Analysis of Two Independent Cohorts from Newfoundland

Introduction

In this study, 27 genetic polymorphisms that were previously reported to be associated with clinical outcomes in colorectal cancer patients were investigated in relation to overall survival (OS) and disease free survival (DFS) in colorectal cancer patients from Newfoundland.

Methods

The discovery and validation cohorts comprised of 532 and 252 patients, respectively. Genotypes of 27 polymorphisms were first obtained in the discovery cohort and survival analyses were performed assuming the co-dominant genetic model. Polymorphisms associated with disease outcomes in the discovery cohort were then investigated in the validation cohort.

Results

When adjusted for sex, age, tumor stage and microsatellite instability (MSI) status, four polymorphisms were independent predictors of OS in the discovery cohort MTHFR Glu429Ala (HR: 1.72, 95%CI: 1.04–2.84, p = 0.036), ERCC5 His46His (HR: 1.78, 95%CI: 1.15–2.76, p = 0.01), SERPINE1 −675indelG (HR: 0.52, 95%CI: 0.32–0.84, p = 0.008), and the homozygous deletion of GSTM1 gene (HR: 1.4, 95%CI: 1.03–1.92, p = 0.033). In the validation cohort, the MTHFR Glu429Ala polymorphism was associated with shorter OS (HR: 1.71, 95%CI: 1.18–2.49, p = 0.005), although with a different genotype than the discovery cohort (CC genotype in the discovery cohort and AC genotype in the validation cohort). When stratified based on treatment with 5-Fluorouracil (5-FU)-based regimens, this polymorphism was associated with reduced OS only in patients not treated with 5-FU. In the DFS analysis, when adjusted for other variables, the TT genotype of the ERCC5 His46His polymorphism was associated with shorter DFS in both cohorts (discovery cohort: HR: 1.54, 95%CI: 1.04–2.29, p = 0.032 and replication cohort: HR: 1.81, 95%CI: 1.11–2.94, p = 0.018).

Conclusions

In this study, associations of the MTHFR Glu429Ala polymorphism with OS and the ERCC5 His46His polymorphism with DFS were identified in two colorectal cancer patient cohorts. Our results also suggest that the MTHFR Glu429Ala polymorphism may be an adverse prognostic marker in patients not treated with 5-FU.     

Combined MRI and 31P-MRS Investigations of the ACTA1(H40Y) Mouse Model of Nemaline Myopathy Show Impaired Muscle Function and Altered Energy Metabolism

Nemaline myopathy (NM) is the most common disease entity among non-dystrophic skeletal muscle congenital diseases. Mutations in the skeletal muscle α-actin gene (ACTA1) account for ∼25% of all NM cases and are the most frequent cause of severe forms of NM. So far, the mechanisms underlying muscle weakness in NM patients remain unclear. Additionally, recent Magnetic Resonance Imaging (MRI) studies reported a progressive fatty infiltration of skeletal muscle with a specific muscle involvement in patients with ACTA1 mutations. We investigated strictly noninvasively the gastrocnemius muscle function of a mouse model carrying a mutation in the ACTA1 gene (H40Y). Skeletal muscle anatomy (hindlimb muscles and fat volumes) and energy metabolism were studied using MRI and ³¹Phosphorus magnetic resonance spectroscopy. Skeletal muscle contractile performance was investigated while applying a force-frequency protocol (from 1–150 Hz) and a fatigue protocol (80 stimuli at 40 Hz). H40Y mice showed a reduction of both absolute (−40%) and specific (−25%) maximal force production as compared to controls. Interestingly, muscle weakness was associated with an improved resistance to fatigue (+40%) and an increased energy cost. On the contrary, the force frequency relationship was not modified in H40Y mice and the extent of fatty infiltration was minor and not different from the WT group. We concluded that the H40Y mouse model does not reproduce human MRI findings but shows a severe muscle weakness which might be related to an alteration of intrinsic muscular properties. The increased energy cost in H40Y mice might be related to either an impaired mitochondrial function or an alteration at the cross-bridges level. Overall, we provided a unique set of anatomic, metabolic and functional biomarkers that might be relevant for monitoring the progression of NM disease but also for assessing the efficacy of potential therapeutic interventions at a preclinical level.     

DOTA-Functionalized Polylysine: A High Number of DOTA Chelates Positively Influences the Biodistribution of Enzymatic Conjugated Anti-Tumor Antibody chCE7agl

Site-specific enzymatic reactions with microbial transglutaminase (mTGase) lead to a homogenous species of immunoconjugates with a defined ligand/antibody ratio. In the present study, we have investigated the influence of different numbers of 1,4,7,10-tetraazacyclododecane-N-N′-N′′-N′′′-tetraacetic acid (DOTA) chelats coupled to a decalysine backbone on the in vivo behavior of the chimeric monoclonal anti-L1CAM antibody chCE7agl. The enzymatic conjugation of (DOTA)₁-decalysine, (DOTA)₃-decalysine or (DOTA)₅-decalysine to the antibody heavy chain (via Gln295/297) gave rise to immunoconjugates containing two, six or ten DOTA moieties respectively. Radiolabeling of the immunoconjugates with ¹⁷⁷Lu yielded specific activities of approximately 70 MBq/mg, 400 MBq/mg and 700 MBq/mg with increasing numbers of DOTA chelates. Biodistribution experiments in SKOV3ip human ovarian cancer cell xenografts demonstrated a high and specific accumulation of radioactivity at the tumor site for all antibody derivatives with a maximal tumor accumulation of 43.6±4.3% ID/g at 24 h for chCE7agl-[(DOTA)-decalysine]₂, 30.6±12.0% ID/g at 24 h for chCE7agl-[(DOTA)₃-decalysine]₂ and 49.9±3.1% ID/g at 48 h for chCE7agl-[(DOTA)₅-decalysine)]₂. The rapid elimination from the blood of chCE7agl-[(DOTA)-decalysine]₂ (1.0±0.1% ID/g at 24 h) is associated with a high liver accumulation (23.2±4.6% ID/g at 24 h). This behavior changed depending on the numbers of DOTA moieties coupled to the decalysine peptide with a slower blood clearance (5.1±1.0 (DOTA)₃ versus 11.7±1.4% ID/g (DOTA)₅, p<0.005 at 24 h) and lower radioactivity levels in the liver (21.4±3.4 (DOTA)₃ versus 5.8±0.7 (DOTA)₅, p<0.005 at 24 h). We conclude that the site-specific and stoichiometric uniform conjugation of the highly DOTA-substituted decalysine ((DOTA)₅-decalysine) to an anti-tumor antibody leads to the formation of immunoconjugates with high specific activity and excellent in vivo behavior and is a valuable option for radioimmunotherapy and potentially antibody-drug conjugates (ADCs).     

Identification of a Novel Human Papillomavirus by Metagenomic Analysis of Samples from Patients with Febrile Respiratory Illness

As part of a virus discovery investigation using a metagenomic approach, a highly divergent novel Human papillomavirus type was identified in pooled convenience nasal/oropharyngeal swab samples collected from patients with febrile respiratory illness. Phylogenetic analysis of the whole genome and the L1 gene reveals that the new HPV identified in this study clusters with previously described gamma papillomaviruses, sharing only 61.1% (whole genome) and 63.1% (L1) sequence identity with its closest relative in the Papillomavirus episteme (PAVE) database. This new virus was named HPV_SD2 pending official classification. The complete genome of HPV-SD2 is 7,299 bp long (36.3% G/C) and contains 7 open reading frames (L2, L1, E6, E7, E1, E2 and E4) and a non-coding long control region (LCR) between L1 and E6. The metagenomic procedures, coupled with the bioinformatic methods described herein are well suited to detect small circular genomes such as those of human papillomaviruses.     

Is Clinical Practice Concordant with the Changes in Guidelines for Antiretroviral Therapy Initiation during Primary and Chronic HIV-1 Infection? The ANRS PRIMO and COPANA Cohorts

Objective

Guidelines for initiating HIV treatment are regularly revised. We explored how physicians in France have applied these evolving guidelines for ART initiation over the last decade in two different situations: chronic (CHI) and primary HIV-1 infection (PHI), since specific recommendations for PHI are also provided in France.

Methods

Data came from the ANRS PRIMO (1267 patients enrolled during PHI in 1996–2010) and COPANA (800 subjects enrolled at HIV diagnosis in 2004–2008) cohorts. We defined as guidelines-inconsistent during PHI and CHI, patients meeting criteria for ART initiation and not treated in the following month and during the next 6 months, respectively.

Results

ART initiation during PHI dramatically decreased from 91% of patients in 1996–99 to 22% in 2007 and increased to 60% in 2010, following changes in recommendations. In 2007, however, after the CD4 count threshold was raised to 350 cells/mm³ in 2006, only 55% of the patients with CD4≤350 were treated and 66% in 2008. During CHI, ART was more frequently initiated in patients who met the criteria at entry (96%) than during follow-up: 83% when recommendation to treat was 200 and 73% when it was 350 cells/mm³. Independent risk factors for not being treated during CHI despite meeting the criteria were lower viral load, lower educational level, and poorer living conditions.

Conclusion

HIV ART initiation guidelines are largely followed by practitioners in France. What can still be improved, however, is time to treat when CD4 cell counts reach the threshold to treat. Risk factors for lack of timely treatment highlight the need to understand better how patients’ living conditions and physicians’ perceptions influence the decision to initiate treatment.     

Silencing of CD44 Gene Expression in Human 143-B Osteosarcoma Cells Promotes Metastasis of Intratibial Tumors in SCID Mice

Osteosarcoma (OS) is the most frequent primary malignant bone cancer in children and adolescents with a high propensity for lung metastasis. Therefore, it is of great importance to identify molecular markers leading to increased metastatic potential in order to devise more effective therapeutic strategies that suppress metastasis, the major cause of death in OS. CD44, the principal receptor for the extracellular matrix component hyaluronan (HA), is frequently found overexpressed in tumor cells and has been implicated in metastatic spread in various cancer types. Here, we investigated the effects of stable shRNA-mediated silencing of CD44 gene products on in vitro and in vivo metastatic properties of the highly metastatic human 143-B OS cell line. In vitro, CD44 knockdown resulted in a 73% decrease in the adhesion to HA, a 57% decrease in the migration rate in a trans-filter migration assay, and a 28% decrease in the cells'' capacity for anchorage-independent growth in soft agar compared to the control cells, implicating that CD44 expression contributes to the metastatic activity of 143-B cells. However, making use of an orthotopic xenograft OS mouse model, we demonstrated that reduced CD44 expression facilitated primary tumor growth and formation of pulmonary metastases. The enhanced malignant phenotype was associated with decreased adhesion to HA and reduced expression of the tumor suppressor merlin in vivo. In conclusion, our study identified CD44 as a metastasis suppressor in this particular experimental OS model.