Hepatitis C virus and the lung: implications for therapy

Unraveling the pathogenesis of viral-induced pulmonary arterial hypertension: Possible new therapeutic avenues with mesenchymal stromal cells and their derivatives

Pulmonary hypertension (PH) is a severe condition characterized by elevated pressure in the pulmonary artery, where metabolic and mitochondrial dysfunction may contribute to its progression. Within the PH spectrum, pulmonary arterial hypertension (PAH) stands out with its primary pulmonary vasculopathy. PAH's prevalence varies from 0.4 to 1.4 per 100,000 individuals and is associated with diverse conditions, including viral infections such as HIV. Notably, recent observations highlight an increased occurrence of PAH among COVID-19 patients, even in the absence of pre-existing cardiopulmonary disorders. While current treatments offer partial relief, there's a pressing need for innovative therapeutic strategies, among which mesenchymal stromal cells (MSCs) and their derivatives hold promise. This review critically evaluates recent investigations into viral-induced PAH, encompassing pathogens like human immunodeficiency virus, herpesvirus, Cytomegalovirus, Hepatitis B and C viruses, SARS-CoV-2, and Human endogenous retrovirus K (HERKV), with a specific emphasis on mitochondrial dysfunction. Furthermore, we explore the underlying rationale driving novel therapeutic modalities, including MSCs, extracellular vesicles, and mitochondrial interventions, within the framework of PAH management.

Extrahepatic Manifestations of Chronic Hepatitis C Virus (HCV) Infection

Hepatitis C virus (HCV) is a well-recognized, major cause of various liver-related conditions such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Apart from liver disease, chronic HCV infection is also associated with several extrahepatic manifestations that can lead to significant morbidity and mortality. These extrahepatic manifestations include essential mixed cryoglobulinemia (EMC), lymphomas, porphyria cutanea tarda, lichen planus, necrolytic acral erythema, glomerulonephritis, subclinical autoantibody formation, immune thrombocytopenia, thyroid disease, Sjögren's disease/sicca symptoms, diabetes mellitus, ocular diseases, musculoskeletal disorders, cardiovascular diseases, neurocognitive dysfunction, and leukocytoclastic vasculitis. We are presenting a case of chronic HCV infection linked to the extrahepatic manifestations of the disease which can be directly related to HCV or indirectly related to EMC from HCV. An awareness and knowledge of these extrahepatic manifestations will highlight the importance of recognizing the symptoms for an early diagnosis and effective anti-viral treatment in order to improve or resolve the long-term complications of chronic HCV infection.

Gender-specific disease trajectories prior to the onset of COPD allow individualized screening and early intervention

BACKGROUND

Nation-wide hospitalization databases include diagnostic information at the level of an entire population over an extended period of time. Comorbidity network and early disease development can be unveiled. Chronic obstructive pulmonary disease (COPD) is an underdiagnosed condition for which it is crucial to identify early disease indicators. The identification of gender-specific conditions preceding the onset of COPD may reveal disease progression patterns allowing for early diagnosis and intervention. The objective of the study was to investigate the antecedent hospitalization history of patients newly diagnosed with COPD and to retrace a gender-specific trajectory of coded entities prior to the onset of COPD.

MATERIAL AND METHODS

A population-wide hospitalization database including information about all hospitalizations in Switzerland between 2002 and 2018 was used. COPD cases were extracted from the database and comorbidities occurring prior to the onset of COPD identified. Comorbidities significantly over-represented in COPD compared with a 1:1, age- and sex-matched control population were identified and their longitudinal evolution was analyzed.

RESULTS

Between 2002 and 2018, 697,714 hospitalizations with coded COPD were recorded in Switzerland. Sixty-two diagnoses were significantly over-represented before onset of COPD. These preceding comorbidities included both well-established conditions and novel links to COPD. Early pre-conditions included nicotine and alcohol abuse, obesity and cardiovascular diseases. Later comorbidities included atrial fibrillation, diseases of the genitourinary system and pneumonia. Atherosclerotic heart diseases were more prevalent in males, whereas hypothyroidism, varicose and intestinal disorders were more frequent in females. Disease trajectories were validated using an independent data set.

CONCLUSIONS

Gender-specific disease trajectories highlight early indicators and pathogenetic links between COPD and antecedent diseases and could allow for early detection and intervention.

Finding undiagnosed patients with hepatitis C infection: an application of artificial intelligence to patient claims data

Hepatitis C virus (HCV) remains a significant public health challenge with approximately half of the infected population untreated and undiagnosed. In this retrospective study, predictive models were developed to identify undiagnosed HCV patients using longitudinal medical claims linked to prescription data from approximately ten million patients in the United States (US) between 2010 and 2016. Features capturing information on demographics, risk factors, symptoms, treatments and procedures relevant to HCV were extracted from patients' medical history. Predictive algorithms were developed based on logistic regression, random forests, gradient boosted trees and a stacked ensemble. Descriptive analysis indicated that patients exhibited known symptoms of HCV on average 2-3 years prior to their diagnosis. The precision was at least 95% for all algorithms at low levels of recall (10%). For recall levels >50%, the stacked ensemble performed best with a precision of 97% compared with 87% for the gradient boosted trees and just 31% for the logistic regression. For context, the Center for Disease Control recommends screening in an at-risk sub-population with an estimated HCV prevalence of 2.23%. The artificial intelligence (AI) algorithm presented here has a precision which is substantially higher than the screening rates associated with recommended clinical guidelines, suggesting that AI algorithms have the potential to provide a step change in the effectiveness of HCV screening.

Utilization of complement receptors in immune cell-microbe interaction

The complement system is a major humoral component of immunity and is essential for the fast elimination of pathogens invading the body. In addition to its indispensable role in innate immunity, the complement system is also involved in pathogen clearance during the effector phase of adaptive immunity. The fastest way of killing the invader is lysis by the membrane attack complex, which is formed by the terminal components of the complement cascade. Not all pathogens are lysed however and, if opsonized by a variety of molecules, they undergo phagocytosis and disposal inside immune cells. The most important complement-derived opsonins are C1q, the first component of the classical pathway, MBL, the initiator of the lectin pathway and C3-derived activation fragments, including C3b, iC3b and C3d, which all serve as ligands for their corresponding receptors. In this review, we discuss how complement receptors are utilized by various immune cells to tackle invading microbes, or by pathogens to evade host response.

Chronic Obstructive Pulmonary Disease and Hepatitis C

Chronic obstructive pulmonary disease (COPD) is a preventable, treatable disease with significant extrapulmonary manifestations that could affect negatively its course in some patients. Hepatitis C virus infection (HCV), on the other hand, is associated with a number of extrahepatic manifestations. COPD patients have increased prevalence of HCV and patients with HCV, especially older ones, have increased prevalence and faster progression of COPD. HCV infection exerts long-term effects on lung tissue and is an additional risk factor for the development of COPD. The presence of HCV is associated with an accelerated loss of lung function in COPD patients, especially in current smokers. COPD could represent extrahepatic manifestation associated with HCV infection. The aim of this article was to review the literature on prevalence of HCV in COPD and vice versa, pathogenetic link and the consequences of their mutual existence.

The impact of hepatitis C viremia status on lung functions in chronic hepatitis c patients

BACKGROUND

Previous trials have investigated the effect of hepatitis C on lung functions; however, the role of viral load levels is unclear. The aim of this study was to investigate the effect of HCV viremia status on lung functions.

METHODS

This study was in 60 patients with chronic hepatitis C (CHC). Patients were classified into three groups (non-viremic, low-viremic and high-viremic) based on serum HCV RNA levels. Spirometric parameters (FEV1, FVC, FEV1/FVC) and the proportion of patients with spirometric abnormalities were compared between three groups.

RESULTS

High-viremic and low-viremic patients showed a significantly higher prevalance of spirometric abnormality than observed in non-viremic patients (p=0.02). Moreover, there was a significant moderate correlation between viremia level and the percentage of spirometric abnormalities (Cramer's U value=0.452, p=0.002). High-viremic patients were 14.2 times more likely to exhibiting pulmonary dysfunction than non-viremic patients. Additionally, spirometric parameters FEV1 and FVC were significantly reduced in high-viremic and low-viremic patients compared to those in non-viremic patients (p=0.013 and p<0.001 respectively).

CONCLUSION

These results indicate that persistent HCV infection may be associated with reduced pulmonary functions, especially in patients with high viremia levels. Therefore, these patients should be carefully monitored for lung function.

Non-specific impairment of Lung Function on Spirometery in Patients with Chronic Hepatitis-C

Objectives:

To document frequency of non-specific impairment of lung functions (NILF) in patients of HCV and to compare according to gender, genotype, liver fibrosis score and smoking status.

Methods:

Patients of chronic hepatitis C were included after informed consent. Demographic data was recorded, and they underwent baseline investigations, fibroscan, abdominal ultrasound and PFT. Patients were segregated on basis of gender, fibroscan stages and smoking status. NILF was labelled if any two of three criteria are fulfilled (a) FVC < 80% of Predicted, (b) FEV1 < 80% Predicted, (c) FEV1/FVC ≥ 70.

Results:

Two hundred thirty four patients were of chronic HCV who fulfilled the selection criteria were inducted in study. These included 49.6% males and 50.4% females. There were 15.0% smokers, 16.2% were ex-smokers while 68.8% were never smokers. NILF was present in 130 (55.6%) out of which 61.5% were female and 38.5% were male (p <0.001), its presence in smokers was 56.2% and in never smokers was 55.3% (p=0.507). Presence of NILF increased with Fibroscan stages from F1 to F4 (p <0.001).

Conclusions:

NILF pattern on spirometry with normal chest radiograph is common among HCV patients. It was found more common in females and frequency increased progressively with fibro scan stages.

Risk of Complications After THA Increases Among Patients Who Are Coinfected With HIV and Hepatitis C

BACKGROUND

Individuals coinfected with both hepatitis C virus (HCV) and HIV represent a unique and growing population of patients undergoing orthopaedic surgical procedures. Data regarding complications for HCV monoinfection or HIV monoinfection are robust, but there are no data available, to our knowledge, on patients who have both HCV and HIV infections.

QUESTIONS/PURPOSES

We sought to determine whether patients with coinfection differed in terms of baseline demographics and comorbidity burden as compared with patients without coinfection and whether these potential differences were translated into varying levels of postoperative complications, mortality, and hospital readmission risk. Specifically, we asked: (1) Are there demonstrable differences in baseline demographic variables between patients infected with HCV and HIV and those who do not have those infections (age, sex, race, and insurance status)? (2) Do patients with HCV and HIV infection differ from patients without those infections in terms of other medical comorbidities? (3) Do patients with HCV/HIV coinfection have a higher incidence of early postoperative complications and mortality than patients without coinfection? (4) Is the frequency of readmission greater for patients with HCV/HIV coinfection than those without?

METHODS

The New York Statewide Planning and Research Cooperative System (SPARCS) database was used to identify patients undergoing THA between 2010 and 2014. The SPARCS database is particularly useful because it captures 100% of all New York State inpatient admissions while providing detailed demographic and comorbidity data for a large, heterogeneous patient population with long-term followup. Patients were stratified into four groups based on HCV/HIV status: control patients without disease, HCV monoinfection, HIV monoinfection, and coinfection. We sought to determine whether patients coinfected with HCV and HIV would differ in terms of demographics from patients without those infections and whether patients with HCV and HIV would have a greater risk of complications, longer length of stay, and hospital readmission. A total of 80,722 patients underwent THA between 2010 and 2014. A total of 98.55% (79,554 of 80,722) of patients did not have either HCV or HIV, 0.66% (530 of 80,722) had HCV monoinfection, 0.66% (534 of 80,722) HIV monoinfection, and 0.13% (104 of 80,722) were coinfected with both HCV and HIV. Multivariate analysis was performed controlling for age, sex, insurance, residency status, diagnosis, and comorbidities to allow for an equal comparison between groups.

RESULTS

Patients with coinfection were more likely to be younger, male (odds ratio [OR], 2.90; 95% confidence interval [CI], 2.20-3.13; p < 0.001), insured by Medicaid (OR, 6.43; 4.41-7.55; p < 0.001), have a history of avascular necrosis (OR, 8.76; 7.20-9.53; p < 0.001), and to be homeless (OR, 6.95; 5.31-7.28; p < 0.001) as compared with patients without HIV or HCV. Additionally, patients with coinfection had the highest proportion of alcohol abuse, drug abuse, and tobacco use along with a high proportion of psychiatric disorders, including depression. HCV and HIV coinfection were independent risk factors for increased length of stay (OR, 1.97; 95% CI, 1.29-3.01; p < 0.001), having two or more in-hospital complications (OR, 1.64; 1.01-2.67; p < 0.001), and 90-day readmission rates (OR, 2.97; 1.86-4.77; p < 0.001).

CONCLUSIONS

As the prevalence of HCV and HIV coinfectivity continues to increase, orthopaedic surgeons will encounter a greater number of these patients. Awareness of the demographic and socioeconomic factors leading to increased complications after THA will allow physicians to consider interventions such as in-hospital psychiatric counseling, advanced discharge planning, and coordination with social work and collaboration with HCV/HIV infectious disease specialists to improve patient health status to improve outcomes and reduce costs.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Other Extrahepatic Manifestations of Hepatitis C Virus Infection (Pulmonary, Idiopathic Thrombocytopenic Purpura, Nondiabetes Endocrine Disorders)

Extrahepatic manifestations of hepatitis C virus (HCV) infection are a rare but serious condition. This article summarizes the current literature on the association between HCV and endocrine and pulmonary manifestations, as well as idiopathic thrombocytopenic purpura (ITP). HCV may directly infect extrahepatic tissues and interact with the immune system predisposing for obstructive and interstitial lung disease, ITP, autoimmune thyroiditis, infertility, growth hormone and adrenal deficiencies, osteoporosis, and potentially lung and thyroid cancers. However, in many cases, the current evidence is divergent and cannot sufficiently confirm a true association, which emphasizes the need for future targeted projects in this field.

Coinfection with Hepatitis C and HIV Is a Risk Factor for Poor Outcomes After Total Knee Arthroplasty

Background

As medical management continues to improve, orthopaedic surgeons are likely to encounter a greater proportion of patients who have coinfection with human immunodeficiency virus (HIV) and hepatitis-C virus (HCV).

Methods

The New York Statewide Planning and Research Cooperative System (SPARCS) database was used to identify patients undergoing total knee arthroplasty between 2010 and 2014. Patients were stratified into 4 groups on the basis of HCV and HIV status. Differences regarding baseline demographics, length of stay, total charges, discharge disposition, in-hospital complications and mortality, and 90-day hospital readmission were calculated.

Results

Between 2010 and 2014, a total of 137,801 patients underwent total knee arthroplasty. Of those, 99.13% (136,604) of the population were not infected, 0.62% (851) had HCV monoinfection, 0.20% (278) had HIV monoinfection, and 0.05% (68) were coinfected with both HCV and HIV. Coinfected patients were more likely to be younger, female, a member of a minority group, homeless, and insured by Medicare or Medicaid, and to have a history of substance abuse. HCV and HIV coinfection was a significant independent risk factor for increased length of hospital stay (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.75 to 4.81), total hospital charges in the 90th percentile (OR, 2.02; 95% CI, 1.12 to 3.67), ≥2 in-hospital complications (OR, 2.04; 95% CI, 1.04 to 3.97), and 90-day hospital readmission (OR, 3.53; 95% CI, 2.02 to 6.18).

Conclusions

Patients coinfected with both HCV and HIV represent a rare but increasing population of individuals undergoing total knee arthroplasty. Recognition of unique baseline demographics in these patients that may lead to suboptimal outcomes will allow appropriate preoperative management and multidisciplinary coordination to reduce morbidity and mortality while containing costs.

Level of Evidence

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Trends in Epidemiology of COPD in HIV-Infected Patients in Spain (1997-2012)

Purpose

The aim of this study was to estimate trends of incidence of hospital admissions and in-hospital mortality (IHM) in HIV-infected patients with COPD in the combination antiretroviral therapy (cART) era in Spain (1997–2012).

Methods

A retrospective study with data from nationwide population-based COPD diagnoses in the Spanish Minimum Basic Data Set (MBDS) was performed. We established groups according to their HIV and HCV infections: 1) HIV-uninfected patients; 2) HIV-infected patients (with or without HCV coinfection).

Results

1,580,207 patients discharge with a COPD diagnosis were included in the study, 8902 of them were HIV-infected patients (5000 HIV-monoinfected patients and 3902 HIV/HCV-coinfected patients). The HIV-infected patients had higher incidence rates of hospital admissions for COPD than the HIV-uninfected patients during the study period. The HIV-monoinfected patients had higher rates of hospitalizations for COPD than the HIV/HCV-coinfected patients in the early-period cART (1997–1999), but these rates decreased in the first group and increased in the second, being even similar in both groups in the late-period cART (2004–2011). On the other hand, the HIV-infected patients with COPD had higher IHM than the HIV-uninfected patients with COPD. The mortality rates were higher in the HIV-monoinfected patients with COPD than in the HIV/HCV-coinfected patients with COPD in the early-period cART; however, in the late-period cART, the mortality rates trends seems higher in the HIV/HCV group. The likelihood of death in HIV/HCV-coinfected patients with COPD was similar to than in HIV-monoinfected patients with COPD.

Conclusions

Incidence of hospital admissions for COPD and IHM have decreased among HIV-monoinfected individuals but have increased steadily among HIV/HCV-coinfected individuals in the cART era.

Pharmacological treatment of HIV-associated pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a rare but severe disease that results from chronic obstruction of small pulmonary arteries, leading to right ventricular failure and, ultimately, death. One established risk factor for the development of PAH is HIV infection. The presence of PAH is an independent risk factor for mortality in HIV-infected patients. This article will focus on HIV-associated PAH (HIV-PAH) with special considerations to the available treatments. With the approval of the soluble guanylate cyclase stimulator riociguat, a new drug class has become available in addition to the already existing prostanoids, endothelin receptor antagonists, and phosphodiesterase type 5 inhibitors. Guidelines for the treatment of idiopathic PAH and guidelines for antiretroviral therapy should be followed for the treatment of HIV-PAH.

Brief Report: Coordinated Modulation of Circulating miR-21 in HIV, HIV-Associated Pulmonary Arterial Hypertension, and HIV/Hepatitis C Virus Coinfection

Dysregulation of microRNA-21 (miR-21) is independently associated with HIV infection, pulmonary arterial hypertension (PAH), and hepatitis C virus (HCV) infection. To assess the expression of miR-21 in these overlapping comorbidities, we measured plasma miR-21 in HIV with and without PAH and then stratified by concomitant HCV infection. MiR-21 was increased in HIV and HIV-PAH versus uninfected subjects, but it did not differ between these groups. HIV/HCV coinfection correlated with even higher miR-21 levels within the HIV-infected population. These data reveal specific regulation of plasma miR-21 in HIV, HIV/HCV coinfection, and PAH and suggest that miR-21 may integrate complex disease-specific signaling in the setting of HIV infection.

Risk of echocardiographic pulmonary hypertension in individuals with human immunodeficiency virus-hepatitis C virus coinfection

RATIONALE

Human immunodeficiency virus (HIV) infection is a risk factor for pulmonary hypertension (PH). Chronic hepatitis C virus (HCV) infection may have unique or synergistic effects on the pulmonary vasculature, but the prevalence and risk factors for PH in HIV-HCV coinfected persons are not known.

OBJECTIVES

To define the prevalence of echocardiographic PH in a cohort of patients with HIV-HCV coinfection, to compare this estimate with the reported prevalence of PH among those with HIV infection alone, and to identify potential risk factors for PH in coinfected individuals.

METHODS

We performed a retrospective study of HIV-HCV coinfected patients followed at our institution from 2003 to 2012 with evidence of HCV infection (positive HCV antibody, measurable HCV ribonucleic acid viral load, and/or genotype) within 6 months of transthoracic echocardiogram. PH was defined by an estimated pulmonary artery systolic pressure (PASP) of greater than or equal to 40 mm Hg or more than moderate right ventricular dysfunction. We excluded those diagnosed with cirrhosis, left ventricular ejection fraction less than 50%, or more than moderate aortic or mitral valve disease.

MEASUREMENTS AND MAIN RESULTS

Sixty-eight patients were included, and 43 had adequate estimates of PASP. The median (interquartile range) age was 52 (48-57) years, and 45 (67%) were men. Eight (19%) had PH, and three (7%) had more than moderate right ventricular dysfunction. After age and sex adjustment, interferon (IFN)-based HCV treatment was associated with higher PASP (β, 6.00 mm Hg; 95% confidence interval, 0.09-11.90; P = 0.047) and with the risk of PH (odds ratio, 5.65; 95% confidence interval, 1.07-29.93; P = 0.042). These associations persisted after adjustment for comorbidities but were attenuated by adjustment for duration of HCV diagnosis.

CONCLUSIONS

The prevalence of echocardiographic PH may be higher in HIV-HCV coinfected individuals than in those with HIV monoinfection. IFN-based HCV treatment and time since HCV diagnosis were associated with the development of PH as assessed by echocardiography. Further studies are needed to examine HIV-HCV coinfection, HCV treatment, and duration of infection as possible causes of pulmonary vascular disease.

The association of exposure to hepatitis B and C viruses with lung function and respiratory disease: a population based study from the NHANES III database

BACKGROUND

Globally, 500 million people are chronically infected with Hepatitis B virus (HBV) and Hepatitis C virus (HCV). While these viruses are notorious for their detrimental effect on the liver they are also known to affect multiple organs in the body including the lungs.

AIM

To investigate if exposure to HBV and HCV is associated with lung function and respiratory diseases.

METHODS

Data from the Third National Health and Nutrition Examination Survey (NHANES III) was analysed using multiple linear regressions to investigate the association between exposure to HBV and HCV with the various measures of lung function, while multiple logistic regressions were used to evaluate the association with the respiratory diseases asthma and chronic obstructive pulmonary disease (COPD).

RESULTS

Exposure to HCV was significantly associated with an increase in Forced Expiratory Volume in 1 s, FEV1 (Coef: 97.94 ml, 95% CI: 38.87 to 157.01) and Full Vital Capacity, FVC (Coef: 90 ml, 95% CI: 14.50 to 166.24). Individuals who had been exposed to both HBV and HCV also had a significantly higher FEV1 (Coef: 145.82, CI: 60.68 to 230.94) and FVC (Coef: 195.09, CI: 78.91 to 311.26). There was also a significant association between exposure to HBV and asthma (OR: 1.28, 95% CI: 1.05 to 1.58). These associations were no longer significant after additionally adjusting for cocaine and marijuana use as well as poverty income ratio.

CONCLUSION

Our research implies that hepatotropic viruses may affect the respiratory system, but more work at a population level is needed to further explore these associations.

A Study of the Interaction between Hepatitis C Virus Infection and Pulmonary Disorders: Assessment of Interferon Gamma and Alpha-1-Antitrypsin

Objectives: To study lung diseases in chronic HCV infection and vice versa and to find immunological and/or hereditary interrelating factors.Material and Methods: Study included 134 individuals, all were subjected to screening for anti-HCV antibodies by ELISA, HCV-RNA by real time PCR, pulmonary function tests, quantitative assay of interferon gamma and alpha-1- antitrypsin in serum by ELISA and genotyping of alpha-1- antitrypsin gene by Light Cycler PCR.Results: 76.5% of chronic HCV patients had abnormal PFT (P = 0.03), mainly reduced DLCO and reversible airway obstruction, and 41.6% of chest diseased patients were HCV-positive with a significant decrease in large and small airways functions. Interferon therapy improved PFT parameters. Only 33% of chronic HCV infection affected by chest abnormality responded to interferon therapy while 50% of chest free patients did. Serum IFN-γ was higher in HCV and chest patients than in control (P=0.02). All serum α1AT deficient patients had M/null genotype.Conclusions: A pathogenic role of chronic HCV infection in lung diseases is evident. Interferon treatment may reduce chest complications and improve pulmonary functions. However, chest affection may reduce the response to interferon treatment. M/null genotype of α1AT gene might play a role in chronic HCV infection and chest co-affection.

Hepatitis C virus infection is not an independent risk factor for obstructive lung disease

Several epidemiological studies have suggested that hepatitis C virus (HCV) infection is associated with the presence of obstructive lung disease (OLD). However, there is a strong link between HCV infection and tobacco abuse, a major risk factor for the development of OLD. In this study we analyzed clinical, laboratory and spirometric data from 1068 study participants to assess whether HCV infection, viremia, or HCV-associated end organ damage were associated with OLD. Demographics, risk behavior, serologic status for HCV and HIV, and spirometric measurements were collected from a cross-sectional analysis of the Acquired Immunodeficiency Syndrome (AIDS) Linked to the IntraVenous Experience (ALIVE) study, an observational cohort of IDUs followed in Baltimore, MD since 1988. Of 1,068 participants, 890 (83%) were HCV positive and 174 (16%) met spirometric criteria for OLD. Factors independently associated with OLD were age and BMI. HCV infection, viral load and HCV-associated end organ damage were similar in participants with and without OLD. In summary, there was no independent association between markers of HCV exposure, chronicity, viremia, or HCV-associated end-organ damage with OLD. Our findings support the strong correlation between HCV status, injection drug use, and smoking. These data suggest that HCV may not be a sole contributor to the increased prevalence of OLD described in previous studies of HCV-infected individuals.

Venous outflow obstruction and portopulmonary hypertension after orthotopic liver transplantation

Patient: Female, 54

Final Diagnosis: Suprahepatic inferior vena cava anastomosis stricture

Symptoms: Ascites • fatigue • lower limb edema • hepatomegaly

Medication: —

Clinical Procedure: —

Specialty: Transplantology • Critical Care Medicine

Decline in pulmonary function during chronic hepatitis C virus therapy with modified interferon alfa and ribavirin

Rare interstitial lung disease cases have been reported with albinterferon alfa-2b (albIFN) and pegylated interferon alfa-2a (Peg-IFNα-2a) in chronic hepatitis C virus (HCV) patients. Systematic pulmonary function evaluation was conducted in a study of albIFN q4wk vs Peg-IFNα-2a qwk in patients with chronic HCV genotypes 2/3. Three hundred and ninety-one patients were randomly assigned 4:4:4:3 to one of four, open-label, 24-week treatment groups including oral ribavirin 800 mg/d: albIFN 900/1200/1500 μg q4wk or Peg-IFNα-2a 180 μg qwk. Standardized spirometry and diffusing capacity of the lung for carbon monoxide (DLCO) were recorded at baseline, weeks 12 and 24, and 6 months posttreatment, and chest X-rays (CXRs) at baseline and week 24. Baseline spirometry and DLCO were abnormal in 35 (13%) and 98 (26%) patients, respectively. Baseline interstitial CXR findings were rare (4 [1%]). During the study, clinically relevant DLCO declines (≥15%) were observed in 173 patients (48%), and were more frequent with Peg-IFNα-2a and albIFN 1500 μg; 24 weeks posttreatment, 57 patients (18%) still had significantly decreased DLCO, with a pattern for greater rates with albIFN vs Peg-IFNα-2a. One patient developed new interstitial CXR abnormalities, but there were no clinically relevant interstitial lung disease cases. The risk of persistent posttreatment DLCO decrease was not related to smoking, alcohol, HCV genotype, sustained virologic response, or baseline viral load or spirometry. Clinically relevant DLCO declines occurred frequently in chronic HCV patients receiving IFNα/ribavirin therapy and commonly persisted for ≥6 months posttherapy. The underlying mechanism and clinical implications for long-term pulmonary function impairment warrant further research.

Diagnostic workup for diffuse parenchymal lung disease: schematic flowchart, literature review, and pitfalls

PURPOSE

The term diffuse parenchymal lung disease (DPLD) refers to a group of disorders affecting the lung parenchyma that can be categorized into those of known and those of unknown etiology. Early diagnosis is important since some forms of DPLD are characterized by a rapid progression to respiratory failure. Notwithstanding the fact that recently guidelines have been published, some issues concerning the practical evaluation of a patient with suspected DPLD remain unclear.

METHODS

In this article we propose a practical approach to the diagnosis and differentiation of DPLD. Moreover, a critical appraisal is provided based on the current literature and frequent pitfalls are highlighted.

CONCLUSION

we propose a practical workup, but in spite of increasing evidence concerning the diagnosis of DPLD, further studies will be needed to clarify several issues for efficient investigation of newly diagnosed patients with DPLD.

[Pulmonary hypertension: from molecular pathophysiology to haemodynamic abnormalities]

Pulmonary hypertension (PH) is a complex disorder resulting from many etiologies that cause disturbances of normal pulmonary haemodynamics. Recent breakthroughs have led to a better understanding of the pathophysiology of the disease. In PH, haemodynamic disturbances are closely linked to structural changes and excessive remodeling of pulmonary vessels, leading to progressive narrowing of the pulmonary vascular lumen. Imbalances between pulmonary vasoconstrictors and vasodilators on the one hand, and factors favoring cell proliferation and apoptosis on the other hand, probably account for most cases of PH. This review aims to update readers with the current knowledge on the molecular physiopathology of PH and how this can progress the therapeutic of this disorder.

[Pulmonary hypertension in patients infected with human immunodeficiency virus: current situation]

The increase in survival that has been achieved with the new treatments in the era of highly active antiretroviral therapy, has enabled clinicians and researchers to analyze issues that emerge in the long term in patients with HIV infection. Although the majority of cardiovascular complications have been widely described, the pathogenesis of pulmonary arterial hypertension is still poorly understood, and is one of the more complex and feared complications as it worsens the prognosis and quality of life of these patients This article reviews newer aspects related to the aetiology, symptoms, diagnosis and treatment of this disease.

Drug-induced lung injury associated with sorafenib: analysis of all-patient post-marketing surveillance in Japan

BACKGROUND

Sorafenib is a multi-kinase inhibitor currently approved in Japan for unresectable and/or metastatic renal cell carcinoma and unresectable hepatocellular carcinoma. Although drug-induced lung injury has recently been the focus of interest in Japanese patients treated with molecular targeting agents, the clinical features of patients receiving sorafenib remain to be completely investigated.

METHODS

All-patient post-marketing surveillance data was obtained within the frame of Special Drug Use Investigation; between April 2008 and March 2011, we summarized the clinical information of 62 cases with drug-induced lung injury among approximately 13,600 sorafenib-treated patients in Japan. In addition, we summarized the results of evaluation by a safety board of Japanese experts in 34 patients in whom pulmonary images were available. For the calculation of reporting frequency, interim results of Special Drug Use Investigation were used.

RESULTS

In the sets of completed reports (2,407 in renal cell carcinoma and 647 in hepatocellular carcinoma), the reporting frequency was 0.33 % (8 patients; fatal, 4/8) and 0.62 % (4 patients; fatal, 2/4), respectively. Major clinical symptoms included dyspnea, cough, and fever. Evaluation of the images showed that 18 cases out of 34 patients had a pattern of diffuse alveolar damage. The patients with hepatocellular carcinoma showed a greater incidence and earlier onset of lung injury than those with renal cell carcinoma.

CONCLUSION

Although the overall reporting frequency of sorafenib-induced lung injury is not considered high, the radiological diffuse alveolar damage pattern led to a fatal outcome. Therefore, early recognition of sorafenib-induced lung injury is crucial for physicians and patients.

Chronic hepatitis C virus infection is associated with more severe asthma

BACKGROUND

Chronic hepatitis C virus (HCV) infection causes intra- and extra-hepatic complications. The elimination of HCV has been reported to be beneficial for asthmatic patients with HCV infection. Therefore, we hypothesized that chronic HCV infection might be associated with the severity of asthma.

METHODS

Asthmatic patients were prospectively enrolled from 13 outpatient settings. Hepatitis B surface (HBs) antigen and HCV-RNA were measured at the time of enrollment and evaluated along with the clinical characteristics of the patients including the age, sex, duration of asthma, atopic status, smoking history, and treatment step according to the Global Initiative for Asthma guideline.

RESULTS

Of 1327 asthmatic patients, 1258 patients (94.8%) were treated with inhaled corticosteroids, 18 patients were positive for HBs antigen (1.4%), and 32 patients (2.4%) were positive for HCV-RNA. When compared with HCV-RNA-negative patients, HCV-RNA-positive patients required significantly more drugs for the treatment of asthma. No such relationship was observed in patients with positive HBs antigen. A multivariate logistic regression analysis showed that the male sex, a long duration of asthma, status as a current smoker, and HCV-RNA positivity were independently associated with more severe asthma.

CONCLUSIONS

These results suggest that chronic HCV infection is an independent factor that predisposes asthmatic patients to more severe asthma. The evaluation of chronic HCV infection may be helpful for the management of severe asthmatic patients without obvious factors associated with severe asthma.

Complement and viral pathogenesis

The complement system functions as an immune surveillance system that rapidly responds to infection. Activation of the complement system by specific recognition pathways triggers a protease cascade, generating cleavage products that function to eliminate pathogens, regulate inflammatory responses, and shape adaptive immune responses. However, when dysregulated, these powerful functions can become destructive and the complement system has been implicated as a pathogenic effector in numerous diseases, including infectious diseases. This review highlights recent discoveries that have identified critical roles for the complement system in the pathogenesis of viral infection.

Immune modulation of ovalbumin-induced lung injury in mice using β-glucosylceramide and a potential role of the liver

CD1d-restricted natural killer T (NKT) cells are implicated in the pathogenesis of asthma. β-Glucosylceramide (GC), a naturally occurring lipid, was previously shown to alter NKT cell distribution in the liver. We hypothesized that GC can affect lung and liver NKT cell distribution and ameliorate asthma. Mice were sensitized by intra-peritoneal injection of ovalbumin (OVA) for 2 weeks followed by repeated intranasal OVA challenges to induce lung injury mimicking asthma. OVA induced asthma groups were either treated by intranasal instillation of normal saline, intranasal instillation of GC or inhaled budesonide. To investigate the role of the liver, hepatic fibrosis was induced using carbon tetrachloride prior to asthma induction. Allergen induced bronchoconstriction was measured prior to sacrifice. Isolated lymphocytes from lungs, livers and spleens were analyzed for OVA induced proliferation and flow cytometry. Liver and lung histology, serum aminotransferase and anti-OVA antibodies level were assessed. Treatment with GC significantly reduced OVA induced airway responsiveness (p<0.001) similar to inhaled budesonide. GC significantly reduced the peri-bronchial and peri-vascular inflammatory infiltration mainly through an effect on T cells, as suggested by decreased T cell proliferation (p=0.009). Liver CD4 and NKT cells significantly increased after GC treatment suggesting liver involvement. Inducing hepatic fibrosis blunted the propagation of asthma in spite of sufficient increase of serum anti-OVA titers. GC has an immunomodulatory effect on a murine model of experimental asthma. We also suggest that the liver acts as an immunomodulatory organ and might have a regulatory effect on pulmonary diseases.

Albinterferon Alfa-2b was not inferior to pegylated interferon-α in a randomized trial of patients with chronic hepatitis C virus genotype 2 or 3

BACKGROUND & AIMS

A phase 3 active-controlled study was conducted to assess the efficacy/safety of albinterferon alfa-2b (albIFN), a novel, long-acting, genetic fusion polypeptide of recombinant human albumin and interferon alfa-2b, in patients with chronic hepatitis C virus (HCV) genotype 2/3.

METHODS

In all, 933 patients were randomized to open-label subcutaneous treatment with pegylated interferon-alfa-2a (Peg-IFNalfa-2a) 180 μg/wk, or albIFN 900 or 1200 μg every 2 weeks for 24 weeks, each administered with oral ribavirin 800 mg/day. The primary end point of the study was sustained virologic response (SVR) (HCV-RNA level, <15 IU/mL at week 48). During the study, the data monitoring committee recommended dose modification for all patients receiving albIFN 1200 μg to 900 μg, impacting 38% of this treatment arm.

RESULTS

By intention-to-treat analysis, SVR rates were 84.8% (95% confidence interval, 80.4%-88.6%), 79.8% (95% confidence interval, 74.9%-84.1%), and 80.0% (95% confidence interval, 75.1%-84.3%) with Peg-IFNalfa-2a, and albIFN 900 and 1200 μg, respectively. The primary hypothesis of noninferiority of SVR was established for albIFN 900 μg (P = .009) and 1200 μg (P = .006). Independent positive predictors of SVR by multivariate regression analysis were pretreatment HCV-RNA level less than 400,000 IU/mL, age younger than 45 years, body mass index less than 30 kg/m(2), genotype 2, normal γ-glutamyl transpeptidase and increased alanine aminotransferase levels at baseline, fibrosis stage F0-F2, no steatosis, and Asian geographic region (Peg-IFNalfa-2a only). The 3 treatment groups showed similar rates of serious (7%-8%) and severe (13%-16%) adverse events, and discontinuations owing to adverse events (3.6%-5.5%).

CONCLUSION

Albinterferon alfa-2b 900 μg every 2 weeks provides an alternative efficacious treatment option in patients with chronic HCV genotype 2 or 3.

Albinterferon Alfa-2b was not inferior to pegylated interferon-α in a randomized trial of patients with chronic hepatitis C virus genotype 1

BACKGROUND & AIMS

The current standard of care for patients with chronic hepatitis C virus (HCV) genotype 1 is once-weekly pegylated interferon-α (Peg-IFNα) plus daily ribavirin for 48 weeks. We evaluated the efficacy/safety of albinterferon alfa-2b (albIFN), a novel, long-acting, genetic fusion polypeptide of albumin and IFNα-2b.

METHODS

In the phase 3 ACHIEVE-1 trial, 1331 patients were assigned equally to 3 open-label, 48-week treatment groups: Peg-IFNα-2a 180 μg every week, or albIFN 900 or 1200 μg every 2 weeks administered subcutaneously, with weight-based oral ribavirin 1000-1200 mg/day. During the study, the data monitoring committee recommended dose modification for all patients receiving albIFN 1200 μg to 900 μg because of increased pulmonary adverse events (AEs) in the 1200-μg arms of both ACHIEVE studies. Main outcome measure was sustained virologic response (SVR; undetectable serum HCV RNA at week 72).

RESULTS

Intention-to-treat SVR rates were 51.0% (225/441), 48.2% (213/442), and 47.3% (208/440) with Peg-IFNα-2a, and albIFN 900 and 1200 μg, respectively. The primary objective of showing noninferiority of albIFN 900 μg (P < .001) and 1200 μg (P = .003) vs Peg-IFNα-2a for SVR was achieved. Multivariate modeling indicated consistency of treatment effect across subgroups. Serious/severe AE rates were 23.1%, 24.0%, 28.2%; treatment discontinuation rates because of AEs were 4.1%, 10.4%, 10.0%; discontinuation rates because of respiratory AEs were 0%, 0.9%, 1.6%; with Peg-IFNα-2a, and albIFN 900 and 1200 μg, respectively. Hematologic abnormality rates were comparable across the Peg-IFNα-2a and albIFN 900-μg groups.

CONCLUSIONS

albIFN 900 μg every 2 weeks showed comparable efficacy, with similar serious/severe AE rates, although with a higher discontinuation rate, vs Peg-IFNα-2a in patients with chronic HCV genotype 1.

Hepatitis C: the complications of immune dysfunction

Hepatitis C virus (HCV) infection has been linked to numerous diseases of immune dysfunction, including, but not limited to, essential mixed cryoglobulinemia and non-Hodgkin's lymphoma. Clinical studies support these associations and treatment of the underlying HCV infection has been variably successful. Recent studies, focusing on the role of HCV gene products, have discovered evidence of dysregulated responses in multiple aspects of host immunity that may be contributing to the genesis of these diseases. Novel treatments that target these areas of dysregulation offer hope for improved therapy for the diseases associated with immunodysregulation by HCV.

The complex interrelationships between chronic lung and liver disease: a review

Lung complications may occur as a result of hepatic disease from any cause and represent a highly heterogeneous group of conditions. Early recognition of such complications may be challenging but is crucial both in forming a meaningful differential diagnosis and in avoiding severe sequelae and irreversible damage. Although a number of different pathogenetic mechanisms are likely to be involved, chronic liver dysfunction may cause pulmonary manifestations because of alterations in the production or clearance of circulating cytokines and other mediators. This is likely to be the case in hepatopulmonary syndrome, portopulmonary hypertension and primary biliary cirrhosis, although their pathogenesis remains largely speculative. Moreover, the severity of lung manifestations may or may not correspond to that of liver impairment, making disease outcome often unpredictable. Congenital and inflammatory disorders, however, may primarily affect both the liver and lung. Apart from specific diseases, a number of medications can also result in pulmonary and hepatic toxic effects. This is particularly important with cytokine therapy - used to treat viral hepatitis, among other diseases - because treatment consists of drug discontinuation, which, in turn, may cause reactivation or progression of the underlying disease that the drug was used for. This review summarizes salient diagnostic and therapeutic aspects of these often misdiagnosed conditions and highlights, based on the most recent literature, the need for early referral of such patients to centres with specific expertise in the field. In fact, a multidisciplinary approach involving pulmonologists, hepatologists and, in particularly severe cases, transplant surgeons has been already proven successful.

Genomics of pulmonary arterial hypertension: implications for therapy

Pulmonary arterial hypertension (PAH) remains a vexing clinical disease with no cure. Despite advances and the discovery of a gene (BMPR2) associated with many of the hereditary forms of the disease, and some cases not previously known to be inherited, the reasons for mutations in this gene as a cause remain somewhat elusive. Clearly, a complex interplay exists between genetic alterations, environmental exposures (including infections), and disease development. This article addresses the advances in the genetics of PAH, including the identification of genetic etiologies and modulators, and the role of genetics in predicting disease progression and targeting therapeutics.

Inflammation, growth factors, and pulmonary vascular remodeling

Inflammatory processes are prominent in various types of human and experimental pulmonary hypertension (PH) and are increasingly recognized as major pathogenic components of pulmonary vascular remodeling. Macrophages, T and B lymphocytes, and dendritic cells are present in the vascular lesions of PH, whether in idiopathic pulmonary arterial hypertension (PAH) or PAH related to more classical forms of inflammatory syndromes such as connective tissue diseases, human immunodeficiency virus (HIV), or other viral etiologies. Similarly, the presence of circulating chemokines and cytokines, viral protein components (e.g., HIV-1 Nef), and increased expression of growth (such as vascular endothelial growth factor and platelet-derived growth factor) and transcriptional (e.g., nuclear factor of activated T cells or NFAT) factors in these patients are thought to contribute directly to further recruitment of inflammatory cells and proliferation of smooth muscle and endothelial cells. Other processes, such as mitochondrial and ion channel dysregulation, seem to convey a state of cellular resistance to apoptosis; this has recently emerged as a necessary event in the pathogenesis of pulmonary vascular remodeling. Thus, the recognition of complex inflammatory disturbances in the vascular remodeling process offers potential specific targets for therapy and has recently led to clinical trials investigating, for example, the use of tyrosine kinase inhibitors. This paper provides an overview of specific inflammatory pathways involving cells, chemokines and cytokines, cellular dysfunctions, growth factors, and viral proteins, highlighting their potential role in pulmonary vascular remodeling and the possibility of future targeted therapy.

Prevalence of hepatitis C virus infection in patients with COPD

Some studies have suggested that chronic hepatitis C virus (HCV) infection may induce an accelerated decline of forced expiratory volume in 1 second (FEV1). We performed a cross-sectional study to determine the prevalence of HCV infection in a sample of chronic obstructive pulmonary disease (COPD) patients and in a control group of blood donors. The clinical characteristics of HCV-positive and HCV-negative patients were compared. Anti-HCV antibody was determined and confirmed by HCV-RNA. The prevalence of HCV infection in COPD patients was 7·5% (95% CI 6·52–8·48) and in blood donors was 0·41% (95% CI 0·40–0·42). The HCV-positive patients had a lower FEV1 (34·7±8·6%) and a higher BODE index (median=6) than HCV-negative patients (42·7±16·5%, median=4, respectively) (P=0·011 and 0·027, respectively). Our results suggest a high prevalence of chronic HCV infection in patients with COPD in comparison with the blood donors. HCV-positive patients have a more severe disease.

[Complexity in asthma: inflammation and scale-free networks]

Our understanding of asthma has traditionally been based on linear deterministic relationships of the type stimulus-bronchial hyperresponsiveness-obstruction-symptoms. This notion however neglects the fact that nonlinear relationships may be present. To better define the disease, some authors therefore suggest that we should think in terms of complex systems with a scale-free topology. The idea of multiple inflammatory hits proposed by the group of Pavord is in its broadest sense a further contribution to this line of thought. According to this theory, the coexistence of additional inflammatory stimuli, which may or may not be localized to the lungs, are responsible for deteriorating lung function. The effects of these stimuli may be additive or act in synergy with the underlying inflammation of asthma itself. In addition to the practical implications, this hypothesis serves as a reminder that the body is made up of interconnected parts and that the pathogenesis of asthma includes distinct elements linked together. If this hypothesis proves valid, future approaches should start to look for the hubs in this network that constitutes asthma, and attempt to integrate information from genomics, proteomics, and metabolomics.

Pathology of pulmonary hypertension

The secondary role of pathology in the present clinical management of pulmonary hypertension (PH) reflects to some extent the limitations of the current understanding of the disease. Ample room exists for the diagnostic translation of the pathobiologic studies, with the goal of improving the diagnostic and prognostic power of the pathologic assessment of pulmonary vascular remodeling. This article seeks to show the complementarities of the pathology and pathobiology of PH.

Pulmonary alterations in patients with chronic HCV infection

BACKGROUND

Chronic hepatitis C virus infection has been reported in association with several extrahepatic manifestations. Included in this list is interstitial lung involvement.

AIMS

The aim of the present study was to evaluate pulmonary alterations in patients with chronic hepatitis C virus infection.

PATIENTS

Twenty-one patients with chronic hepatitis C virus infection were enrolled into a prospective study. One patient has been excluded because of underlying tuberculosis.

METHODS

All patients underwent pulmonary function tests, diffusion capacity for carbon monoxide and high-resolution computed tomography of the chest.

RESULTS

Forced vital capacity, forced expiratory volume in first second/forced vital capacity and forced expiratory volume in first second values were reduced to less than 80% of predicted values in 3, 11 and 5 patients, respectively. Diffusion capacity for carbon monoxide was low in 12 patients (60%), 8 of whom had simultaneous decrease in diffusion capacity for carbon monoxide/VA values. Thorax high-resolution computed tomography revealed abnormal findings in eight patients (40%). Fifteen patients with chronic hepatitis C virus infection (75%) had at least one pulmonary alteration as evidenced by abnormal pulmonary function tests, diffusion capacity for carbon monoxide and/or high-resolution computed tomography results.

CONCLUSION

In spite of a limited study population, these findings may implicate that pulmonary manifestations of chronic hepatitis C virus infection are frequently underdiagnosed.