Immune signatures underlying post-acute COVID-19 lung sequelae

[Figure: see text].

POS0325 RADIOMIC BIOMARKER OF PULMONARY VASCULAR RELATED STRUCTURES PREDICTS MORTALITY IN SYSTEMIC SCLEROSIS

Background:

Quantitative computed tomography (QCT) extracts features from high-resolution CT scans and quantifies lung parenchymal and vascular abnormalities which may not be discernable by qualitative review. The threshold values of individual parenchymal abnormalities and vascular features measured by QCT methods which associate with mortality in systemic sclerosis (SSc) are currently unknown.

Objectives:

To determine whether QCT measures, specifically pulmonary parenchymal abnormalities and pulmonary vascular related structures (PVRS), can predict mortality in SSc and to determine the optimal quantitative thresholds for those parameters.

Methods:

A total of 133 subjects (76% women) meeting 2013 ACR/EULAR classification criteria for SSc with a baseline CT within 3 years of diagnosis were retrospectively identified for inclusion. CALIPER (Computer-Aided Lung Informatics for Pathology Evaluation and Rating) was used to quantitatively measure volume of ground glass opacities (GGO), reticular densities, and honeycombing (HC). Total interstitial lung disease (ILD) was the summation of these features. PVRS was also quantified using CALIPER. Values for each feature were expressed as a percentage of total lung volume. Cox models evaluated the hazard ratio (HR) for mortality for each parameter adjusting for age at SSc diagnosis, sex, diffuse SSc subtype, and history of smoking. The optimal thresholds for mortality prediction for each parameter were determined using consensus between 4 methods: Contal and O’Quigley Method, Cox Model Hazard Ratio, Cox Model Wald P-value, and False Discovery Rate. The c-statistic was used to assess each models’ ability to predict mortality.

Results:

Mean ±SD for age at SSc diagnosis was 61 ± 13 years and length of follow-up was 4.7 ± 3.0 years. There were 32 deaths (24%). A Cox model including age (HR 1.05, 95% CI: 1.01-1.09), female sex (HR 0.49, 95% CI: 0.22-1.08), diffuse SSc subtype (HR 1.50, 95% CI: 0.69-3.30), and history of smoking (HR 2.09, 95% CI: 0.97-4.53) (Model 1) significantly predicted mortality (C-statistic 0.72, 95% CI: 0.63-0.81). Adjusting for Model 1, reticular densities% (HR 1.19, 95% CI: 1.05-1.35), total ILD% (HR 1.02, 95% CI: 1.00-1.03), and PVRS% (HR 1.19, 95% CI: 1.05-1.35) were associated with mortality on univariable analyses; GGO% (HR 1.01, 95% CI: 0.98-1.04) was not significantly associated with mortality. The optimal thresholds for mortality prediction were then determined and were as follows: GGO=20%, reticular densities=8%, total ILD=20%, and PVRS=5%. While the risk of mortality was significantly increased in subjects with GGO ≥20% (HR 2.70, 95% CI: 1.21-6.05), reticular densities ≥8% (HR 4.64, 95% CI: 1.68-12.81), and total ILD ≥20% (2.59, 95% CI: 1.12-5.99), these baseline thresholds did not improve upon mortality prediction when added individually to Model 1 (C-statistic 0.73 for each). PVRS ≥5%, which had an over six-fold increase in mortality (HR 6.42, 95% CI: 2.60-15.88), did improve mortality prediction when added to Model 1 (C-statistic 0.78, 95% CI: 0.70-0.86).

Conclusion:

PVRS strongly associates with early mortality in patients with SSc and represents a novel radiomic biomarker that provides prognostic information on mortality beyond pulmonary parenchymal abnormalities. CALIPER derived PVRS quantifies CT data through a function that defines connected tubular branching structures. This extracts pulmonary arteries and veins from the adjacent parenchyma but could potentially also include regions of adjoining of fibrosis.1 Larger studies examining the association between PVRS and progression of cardiopulmonary disease are warranted.

References:

[1]Jacob J, Bartholmai BJ, Rajagopalan S, et al. Predicting Outcomes in Idiopathic Pulmonary Fibrosis Using Automated Computed Tomographic Analysis. Am J Respir Crit Care Med 2018;198:767-76.

Acknowledgements:

This project was supported by the Mayo Clinic Margaret Harvey Schering Clinician Career Development Award.

Disclosure of Interests:

Alicia Hinze: None declared, Yasser Radwan: None declared, Mamoun Elnagar: None declared, Reto Kurmann: None declared, Shreyasee Amin: None declared, Robert Vassallo Grant/research support from: Pfizer, Bristol Myers Squibb, Sun Pharma, Cynthia S. Crowson: None declared, Brian Bartholmai Consultant of: AstraZenica, Boehringer Ingelheim, Promedior LLC (all <$5,000 annually)

POS0210 THE INCIDENCE AND RISK FACTORS OF RHEUMATOID ARTHRITIS-ASSOCIATED INTERSTITIAL LUNG DISEASE

Background:

Rheumatoid arthritis (RA) is a systemic inflammatory disease of the joints and other organs, including the lungs.1 Interstitial lung disease (ILD) is a lung injury pattern associated with significant symptom burden and poor outcomes in RA.2 Better understanding of its risk factors could help with disease prevention and treatment.

Objectives:

Using a population-based cohort, we sought to ascertain the incidence and risk factors of RA-associated ILD (RA-ILD) in recent years.

Methods:

The study included adult residents of Olmsted County, Minnesota with incident RA between 1999 and 2014 based on the 1987 ACR classification criteria.3 Study subjects were followed until death, migration, or 4/30/2019. ILD was defined by the presence of bilateral interstitial fibrotic changes (excluding biapical scarring) on chest computed tomography (CT). In the absence of chest CT imaging, a physician’s diagnosis of ILD in conjunction with chest X-ray findings suggestive of ILD and a restrictive pattern on pulmonary function testing (defined as a total lung capacity less than the lower limit of normal) was considered diagnostic of ILD. Evaluated risk factors included age, sex, calendar year, smoking status, body mass index (BMI) and presence/absence of rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA). Cumulative incidence of ILD was adjusted for the competing risk of death. Cox models were used to assess the association between potential risk factors and the development of RA-ILD.

Results:

In Olmsted County, 645 residents were diagnosed with RA between 1999 and 2014. Seventy percent of patients were females, and 30% were males; median age at RA diagnosis was 55.3 [IQR 44.1-66.6] years, and most patients (89%) were white. Fifty-three percent of patients were never-smokers, and 64% had seropositive RA. Forty percent were obese (i.e., BMI ≥30 kg/m2); median BMI was 28.3 [IQR 24.3-33.0] kg/m2.

In the cohort, ILD was identified in 73 patients. The ILD diagnosis predated RA diagnosis in 22 patients (3.4%) who were excluded from subsequent analyses. Final analyses included the remaining 623 patients with no ILD preceding, or at the time of RA diagnosis. Over a median follow-up interval of 10.2 [IQR 6.5-14.3] years, 51 patients developed ILD. Cumulative incidence of ILD, adjusted for the competing risk of death, was 4.3% at 5 years; 7.8% at 10 years; 9.4% at 15 years; and 12.3% at 20 years after RA diagnosis (Figure 1).

Age, and history of smoking at RA diagnosis correlated with the incidence of ILD; adjusted hazard ratios (HRs) were 1.89 per 10-year increase in age (95% confidence interval 1.52-2.34) and 1.94 (95% confidence interval 1.10-3.42), respectively. On the other hand, sex (HR: 1.21; 95% CI: 0.68-2.17), BMI (HR: 0.99; 95% CI: 0.95-1.04), obesity (HR: 0.89; 95% CI: 0.50-1.58), and seropositivity (HR: 1.15; 95% CI: 0.65-2.03) did not demonstrate significant associations with ILD.

Conclusion:

This study provides a contemporary estimate of the occurrence of ILD in a well-characterized population-based cohort of patients with RA. Our findings of a lack of association between sex, obesity and seropositivity with ILD may indicate a change in established risk factors for ILD and warrant further investigation.

References:

[1]Shaw M, Collins BF, Ho LA, Raghu G. Rheumatoid arthritis-associated lung disease. Eur Respir Rev. 2015;24(135):1-16. doi:10.1183/09059180.00008014

[2]Bongartz T, Nannini C, Medina-Velasquez YF, et al. Incidence and mortality of interstitial lung disease in rheumatoid arthritis - A population-based study. Arthritis Rheum. 2010;62(6):1583-1591. doi:10.1002/art.27405

[3]Aletaha D, Neogi T, Silman AJ, et al. 2010 Rheumatoid arthritis classification criteria: An American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheum. 2010;62(9):2569-2581. doi:10.1002/art.27584

Figure 1.

Cumulative incidence of ILD in patients diagnosed with RA between 1999 and 2014, adjusted for the competing risk of death. Abbreviations. ILD: interstitial lung disease; RA: rheumatoid arthritis.

Disclosure of Interests:

Bilal Samhouri: None declared, Robert Vassallo Grant/research support from: Research grants from Pfizer, Sun Pharmaceuticals and Bristol Myers Squibb, Sara Achenbach: None declared, Vanessa Kronzer: None declared, John M Davis III Grant/research support from: Research grant from Pfizer., Elena Myasoedova: None declared, Cynthia S. Crowson: None declared

Cigarette smoking and inflammation: cellular and molecular mechanisms

Cigarette smoke (CS) causes considerable morbidity and mortality by inducing cancer, chronic lung and vascular diseases, and oral disease. Despite the well-recognized risks associated with smoking, the habit remains unacceptably prevalent. Several toxins present in CS have immunomodulatory effects. CS also contains trace amounts of microbial cell components, including bacterial lipopolysaccharide. These and other CS constituents induce chronic inflammation at mucosal surfaces and modify host responses to exogenous antigens. The effects of CS on immunity are far-reaching and complex; both pro-inflammatory and suppressive effects may be induced. The net effect of CS on immunity depends on many variables, including the dose and type of tobacco, the route and chronicity of exposure, and the presence of other factors at the time of immune cell stimulation, such as Toll receptor ligands or other inflammatory mediators. CS impairs innate defenses against pathogens, modulates antigen presentation, and promotes autoimmunity. CS also impairs immunity in the oral cavity and promotes gingival and periodontal disease and oral cancer. The recognition of specific mechanisms by which CS affects host immunity is an important step toward elucidating mechanisms of tobacco-induced disease and may identify novel therapeutic approaches for the management of diseases that afflict smokers.

Multi-institutional randomized control study of haemolysis in stored red cell units prepared manually or by an automated system

BACKGROUND

The haemolysis level at the end of storage is a performance parameter for RBC preparations. In the evaluation of new devices or new processes for processing blood, it is relevant to evaluate whether the haemolysis is linked to (1) specific characteristics of the blood donor, or (2) the nature of the blood-processing methodologies.

MATERIALS AND METHODS

As part of the validation of a new automated whole blood processing system compared to the current manual methods, randomized, paired crossover studies were conducted evaluating measures of blood component quality, including RBC haemolysis over 42 days of storage.

RESULTS

The association between haemolysis and the individual subject was evaluated by modelling haemolysis with independent predictors of treatment (control and test processing) and leucocyte reduction as fixed factors with donor and laboratory as random effects in a mixed-effects ANOVA model. It was found that the day 42 haemolysis values were strongly dependent on the donor subject, with an intraclass correlation coefficient of 0.81.

CONCLUSIONS

The data reported in this study suggest a link between the specific whole blood donor and the haemolysis levels observed in red-blood-cell units stored refrigerated for 42 days. Additional research to identify possible donor characteristics associated with haemolysis during storage is warranted.

Effectiveness and persistence of a topical treatment for cervical ectropion with deoxyribonucleic acid

AIM

The aim of this study was to estimate short and long term effectiveness of a topical treatment for cervical ectropion with 5 mg of deoxyribonucleic acid (DRNA).

METHODS

A randomized case-control study was carried out. Two-hundred and twenty patients, colposcopically diagnosed with cervical ectropion, were consecutively enrolled and randomly divided into 2 groups: treated (group 1) and controls (group 2). The therapeutic plan consisted of DRNA 5 mg vaginal suppositories, administered for 15 days monthly; subsequently posology was reduced gradually. Both groups underwent a clinical and colposcopical follow-up on the 1st, 4th, 10th and 22nd months after the first examination. At the end of the study, the size of ectropion was considered a parameter of re-epithelialization and provided a criterion of treatment effectiveness. According to this protocol, subjects were defined improved, stable or worsened. Statistical analysis including Pearson chi2 tests, Fisher's exact tests, Yate's corrected chi2 and relative-risk (95% CI) was performed.

RESULTS

Of the 220 enrolled patients, 140 completed the study protocol: 76 treated and 64 controls. Outcomes after treatment and follow-up consisted of: 74 (97.4%) improved in group 1, against 2 cases (3.1%) in group 2. High statistical significance was reported comparing outcome frequencies in the 2 groups (P<0.0001).

CONCLUSIONS

This study shows a significant reduction (P<0.0001) in cervical ectropion size between cases (topical treatment with DRNA 5 mg) and controls. A follow-up of 22 months confirmed the persistence and effectiveness of this medical approach.

[Evaluation of the results after 5 year from a vertical banded gastroplasty: our experience]

BACKGROUND AND AIMS

vertical banded gastroplasty (GPV) is the most frequently performed restrictive procedure for morbid obesity, but long-term follow-up is almost nonexistent. A poor outcome after GPV and a low quality of life has been reported. The aim of the study was to determine long-term outcome after 5 years follow-up.

METHODS

225 GPV were performed from 1995 to 2002. Patients were followed every month in the first three months, after 6 and 12 months, and subsequently every year.

RESULTS

No mortality was observed. One gastric fistula, treated with medical therapy, was the single related complication observed. Vomiting occurred in 21.2% of patients. After 2 years 74.5% of patients had a BMI < 35, with a decrease of IEW = 50% (IEW% L 54.1%, 56.4%, and 57.1% after 12, 24 and 60 months, respectively). After 5 years, the results were unsatisfactory in 17.1% of patients; 8 patients underwent bariatric re-operation with good results.

CONCLUSIONS

GPV represents a safe procedure with a low incidence of complications, with poor results in 17.1% of patients. Pre-operative identification of non responders is achievable with "BIB test". In the responders significant dietary changes are complained.

Vitronectin and fibronectin function as glucan binding proteins augmenting macrophage responses to Pneumocystis carinii

beta-glucans represent major structural components of fungal cell walls. We recently reported that Pneumocystis carinii beta-glucans stimulate alveolar macrophages to release proinflammatory cytokines. Macrophage activation by beta-glucan is augmented by serum, implying the presence of circulating factors that interact with beta-glucans and enhance their ability to stimulate macrophages. Using beta-glucan-enriched cell wall fractions from P. carinii and Saccharomyces cerevisiae, two prominent proteins were precipitated from serum and demonstrated to be vitronectin (VN) and fibronectin (FN) by immune analysis. Preincubation of beta-glucan with VN or FN enhanced macrophage activation in response to this cell wall component. Because VN and FN accumulate in the lungs during P. carinii pneumonia, we further investigated hepatic and pulmonary expression of VN and FN messenger RNA during infection. P. carinii pneumonia in rodents is associated with increased hepatic expression of VN and FN as well as increased local expression of FN in the lung. Because interleukin (IL)-6 represents the major regulator of VN and FN expression during inflammatory conditions, we measured macrophage IL-6 release in response to stimulation with P. carinii beta-glucan. Stimulation of macrophages with P. carinii beta-glucan induced significant release of IL-6. Elevated concentrations of IL-6 were noted in the blood of infected animals compared with uninfected control animals. These studies indicate that VN and FN bind to beta-glucan components of P. carinii and augment macrophage inflammatory responses. P. carinii cell wall beta-glucan stimulates secretion of IL-6 by macrophages, thereby enhancing hepatic synthesis of both VN and FN, and lung synthesis of FN during pneumonia.

Smoking-related interstitial lung diseases: a concise review

Interstitial lung diseases (also known as diffuse infiltrative lung diseases) are a heterogeneous group of parenchymal lung disorders of known or unknown cause. These disorders are usually associated with dyspnoea, diffuse lung infiltrates, and impaired gas exchange. The majority of interstitial lung diseases are of unknown cause. Known causes of interstitial lung disease include inhalation of organic and inorganic dusts as well as gases or fumes, drugs, radiation, and infections. This review summarizes the clinical, radiological, and histopathological features of four interstitial lung disorders that have been linked to smoking. These disorders include desquamative interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease, pulmonary Langerhans' cell histiocytosis, and idiopathic pulmonary fibrosis. Available evidence suggests most cases of desquamative interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease, and pulmonary Langerhans' cell histiocytosis are caused by cigarette smoking in susceptible individuals. Smoking cessation should be a main component in the initial therapeutic approach to smokers with these interstitial lung diseases. In addition, smoking appears to be a risk factor for the development of idiopathic pulmonary fibrosis.

Mechanisms of defence in the lung: lessons from Pneumocystis carinii pneumonia

Pneumocystis carinii continues to represent an important complication of individuals with compromised immunity. P. carinii interacts with immune and non-immune cells in the lung and mediates lung injury through a variety of mechanisms. CD4+ T lymphocytes are the cornerstone in defence against P. carinii. Recent studies indicate that alveolar macrophages provide essential functions that significantly enhance clearance of P. carinii infection. P. carinii also attaches to alveolar epithelial cells, causing inhibition of epithelial growth and replication. In addition to cellular interactions, P. carinii organisms bind to a variety of host adhesive proteins present in the lower respiratory tract. Binding of these proteins to P. carinii modulates host cell recognition and immune responses to the parasite. During the course of P. carinii pneumonia, several inflammatory mediators are produced in the lung. Although necessary for control of infection, exuberant inflammatory responses also predispose the host to the development of acute lung injury. Thus, host defences against P. carinii depend on complex interactions between immune and non-immune cells as well as several mediators that facilitate host recognition and eventual elimination of infection. Understanding these complex processes may enable development of novel therapeutic approaches for management of this important infection.

Isolated Pneumocystis carinii cell wall glucan provokes lower respiratory tract inflammatory responses

Macrophage-induced lung inflammation contributes substantially to respiratory failure during Pneumocystis carinii pneumonia. We isolated a P. carinii cell wall fraction rich in glucan carbohydrate, which potently induces TNF-alpha and macrophage-inflammatory protein-2 generation from alveolar macrophages. Instillation of this purified P. carinii carbohydrate cell wall fraction into healthy rodents is accompanied by substantial increases in whole lung TNF-alpha generation and is associated with neutrophilic infiltration of the lungs. Digestion of the P. carinii cell wall isolate with zymolyase, a preparation containing predominantly beta-1,3 glucanase, substantially reduces the ability of this P. carinii cell wall fraction to activate alveolar macrophages, thus suggesting that beta-glucan components of the P. carinii cell wall largely mediate TNF-alpha release. Furthermore, the soluble carbohydrate beta-glucan receptor antagonists laminariheptaose and laminarin also substantially reduce the ability of the P. carinii cell wall isolate to stimulate macrophage-inflammatory activation. In contrast, soluble alpha-mannan, a preparation that antagonizes macrophage mannose receptors, had minimal effect on TNF-alpha release induced by the P. carinii cell wall fraction. P. carinii beta-glucan-induced TNF-alpha release from alveolar macrophages was also inhibited by both dexamethasone and pentoxifylline, two pharmacological agents with potential activity in controlling P. carinii-induced lung inflammation. These data demonstrate that P. carinii beta-glucan cell wall components can directly stimulate alveolar macrophages to release proinflammatory cytokines mainly through interaction with cognate beta-glucan receptors on the phagocyte.

Multiple cerebral infarctions from nonbacterial thrombotic endocarditis mimicking cerebral vasculitis

Primary vasculitis of the central nervous system (PVCNS) is an uncommon disorder that can present with a variety of symptoms, making diagnosis and management difficult. We describe a case of cerebral infarction that occurred from nonbacterial thrombotic endocarditis (NBTE) and presented with clinical and radiologic imaging features that suggested PVCNS. The patient was a 58-year-old woman with left hemiparesis, aphasia, and episodic confusion. Magnetic resonance imaging of the brain demonstrated multifocal lesions consistent with infarction involving both cerebral hemispheres, and cerebral angiography showed changes consistent with vasculitis. Although brain biopsy findings were normal, the patient was treated for presumed vasculitis with cyclophosphamide and prednisone. Four months later respiratory failure secondary to polymicrobial pneumonia and adult respiratory distress syndrome developed, and she died. Autopsy revealed multiple infarcts in the heart, lungs, right kidney, spleen, and brain. Multiple thrombotic platelet-fibrin vegetations consistent with NBTE were found on all cardiac valves. Examination of the brain revealed no evidence of active or healed vasculitis. Cerebral angiography may show findings that suggest vasculitis, but it is not diagnostic, as several other conditions may cause similar changes. Nonbacterial thrombotic endocarditis may cause multiple cerebral infarctions and can be difficult to distinguish from vasculitis, as specific diagnostic tests for PVCNS are lacking.

Theophylline: recent advances in the understanding of its mode of action and uses in clinical practice

Theophylline, a drug that has been used for several decades, has several different actions at a cellular level, including inhibition of phosphodiesterase isoenzymes, antagonism of adenosine, enhancement of catecholamine secretion, and modulation of calcium fluxes. Recently, theophylline was found to have several immunomodulatory and anti-inflammatory properties, and thus interest in its use in patients with asthma has been renewed. The use of theophylline in the treatment of asthma and chronic obstructive pulmonary disease has diminished with the advent of new medications, but theophylline remains beneficial, especially in the patient with difficult refractory symptoms. In the future, theophylline may be used as treatment for bradyarrhythmias after cardiac transplantation, prophylactic medication to reduce the severity of nephropathy associated with intravenous administration of contrast material, therapy for breathing problems during sleep, and treatment for leukemias.

Expression of the collagen-like putative oncoprotein of Herpesvirus saimiri in transformed T cells

Herpesvirus saimiri induces acute lymphomas and leukemias in New World primates and rabbits. Previous work revealed that a highly oncogenic group C strain 484-77 encodes and expresses a bicistronic mRNA in tumor-derived T cells and the first open reading frame (orf1) is highly homologous to collagen. With the aid of an antibody against a synthetic orf1 peptide, we now report that the orf1 collagen-like protein is expressed in rabbit tumor derived cell lines and in vitro transformed human and monkey T cells. The orf1 protein is expressed in vivo, as indicated by specific antibodies detected in the serum from a tumor-bearing rabbit.

Infection with a plasmid-free variant Chlamydia related to Chlamydia trachomatis identified by using multiple assays for nucleic acid detection

Clinical samples in transport media from 40 patients exhibiting pathologies potentially caused by Chlamydia trachomatis infection were analyzed for chlamydial nucleic acid, and the results were compared with those of culture. Chlamydial culture was performed by a shell vial centrifugation method with HeLa 229 host cells. Polymerase chain reaction (PCR) assays were used to detect either regions on a 7.5-kb plasmid characteristic of C. trachomatis (plasmid-PCR) or a segment of the 16S rRNA genes (rRNA-PCR). All PCR results were confirmed by hybridization with probes for the specific amplified products in either a Southern or a dot blot format. An RNase protection (RNP) assay was used to detect genus-specific chlamydial 16S rRNA directly from the clinical samples. The PCR assays detected C. trachomatis but not other bacteria, including Chlamydia spp. C. trachomatis was isolated from six samples which were positive by the rDNA-PCR and plasmid-PCR assays. Five of the culture-positive specimens were positive by the RNP assay. Twenty-two samples were negative by all criteria. Surprisingly, nine samples were positive by rRNA-PCR and RNP assays only. Nucleic acid sequencing of the rRNA-PCR-amplified products indicated a close relationship between the variants and C. trachomatis. The data may indicate an unrecognized process in C. trachomatis infection or that these patients were infected by a variant strain of C. trachomatis which lacks the C. trachomatis-specific plasmid.