Clinical Outcomes of Patients with Combined Idiopathic Pulmonary Fibrosis and Emphysema in the IPF-PRO Registry

Purpose

To assess the impact of concomitant emphysema on outcomes in patients with idiopathic pulmonary fibrosis (IPF).

Methods

The IPF-PRO Registry is a US registry of patients with IPF. The presence of combined pulmonary fibrosis and emphysema (CPFE) at enrollment was determined by investigators’ review of an HRCT scan. Associations between emphysema and clinical outcomes were analyzed using Cox proportional hazards models.

Results

Of 934 patients, 119 (12.7%) had CPFE. Compared with patients with IPF alone, patients with CPFE were older (median 72 vs 70 years); higher proportions were current/former smokers (88.2% vs 63.7%), used oxygen with activity (49.6% vs 31.9%) or at rest (30.8% vs 18.4%), had congestive heart failure (13.6% vs 4.8%) and had prior respiratory hospitalization (25.0% vs 16.7%); they had higher FVC (median 71.8 vs 69.4% predicted) and lower DLco (median 35.3 vs 43.6% predicted). In patients with CPFE and IPF alone, respectively, at 1 year, rates of death or lung transplant were 17.5% (95% CI: 11.7, 25.8) and 11.2% (9.2, 13.6) and rates of hospitalization were 21.6% (14.6, 29.6) and 20.6% (17.9, 23.5). There were no significant associations between emphysema and any outcome after adjustment for baseline variables. No baseline variable predicted outcomes better in IPF alone than in CPFE.

Conclusion

Approximately 13% of patients in the IPF-PRO Registry had CPFE. Physiologic characteristics and comorbidities of patients with CPFE differed from those of patients with IPF alone, but the presence of emphysema did not drive outcomes after adjustment for baseline covariates.

Trial registration

ClinicalTrials.gov, NCT01915511; registered August 5, 2013.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00408-021-00506-x.

Recombinant human pentraxin-2 therapy in patients with idiopathic pulmonary fibrosis: safety, pharmacokinetics and exploratory efficacy

Abnormal fibrogenic repair response upon alveolar injury is believed to play an important role in the pathogenesis of idiopathic pulmonary fibrosis (IPF). PRM-151 (recombinant human pentraxin-2, also known as serum amyloid P), has been shown to reduce fibrosis in preclinical lung fibrosis models, and was well tolerated with a favourable pharmacokinetic profile in an earlier single-dose phase I study.A randomised, double-blind, placebo-controlled, multiple ascending dose trial was performed to assess the tolerability and pharmacokinetic and pharmacodynamic characteristics of multiple doses of PRM-151 in IPF patients. Subjects in three successive cohorts (1, 5, or 10 mg·kg(-1) versus placebo) received intravenous study drug on days 1, 3, 5, 8 and 15, and were followed-up to day 57.PRM-151 was well tolerated at all dose levels, with no serious adverse reactions. Administration of PRM-151 resulted in two- to eight-fold dose-dependent increases in circulating pentraxin-2 levels. Forced vital capacity and 6-min walk test showed trends towards improvement in the combined PRM-151 dose groups. On high-resolution computed tomography scans, stable or improved lung volume unoccupied by interstitial lung abnormality was noted in some PRM-151 subjects compared to placebo subjects on day 57.The efficacy of PRM-151 in IPF remains to be investigated in dedicated future trials.

Quantitative proteomics of bronchoalveolar lavage fluid in idiopathic pulmonary fibrosis

The proteomic analysis of bronchoalveolar lavage fluid (BALF) can give insight into pulmonary disease pathology and response to therapy. Here, we describe the first gel-free quantitative analysis of BALF in idiopathic pulmonary fibrosis (IPF), a chronic and fatal scarring lung disease. We utilized two-dimensional reversed-phase liquid chromatography and ion-mobility-assisted data-independent acquisition (HDMSE) for quantitation of >1000 proteins in immunodepleted BALF from the right middle and lower lobes of normal controls and patients with IPF. Among the analytes that were increased in IPF were well-described mediators of pulmonary fibrosis (osteopontin, MMP7, CXCL7, CCL18), eosinophil- and neutrophil-derived proteins, and proteins associated with fibroblast foci. For additional discovery and targeted validation, BALF was also screened by multiple reaction monitoring (MRM), using the JPT Cytokine SpikeMix library of >400 stable isotope-labeled peptides. A refined MRM assay confirmed the robust expression of osteopontin, and demonstrated, for the first time, upregulation of the pro-fibrotic cytokine, CCL24, in BALF in IPF. These results show the utility of BALF proteomics for the molecular profiling of fibrotic lung diseases and the targeted quantitation of soluble markers of IPF. More generally, this study addresses critical quality control measures that should be widely applicable to BALF profiling in pulmonary disease.

Treatment of idiopathic pulmonary fibrosis with ambrisentan: a parallel, randomized trial

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is characterized by formation and proliferation of fibroblast foci. Endothelin-1 induces lung fibroblast proliferation and contractile activity via the endothelin A (ETA) receptor.

OBJECTIVE

To determine whether ambrisentan, an ETA receptor-selective antagonist, reduces the rate of IPF progression.

DESIGN

Randomized, double-blind, placebo-controlled, event-driven trial. (ClinicalTrials.gov: NCT00768300).

SETTING

Academic and private hospitals.

PARTICIPANTS

Patients with IPF aged 40 to 80 years with minimal or no honeycombing on high-resolution computed tomography scans.

INTERVENTION

Ambrisentan, 10 mg/d, or placebo.

MEASUREMENTS

Time to disease progression, defined as death, respiratory hospitalization, or a categorical decrease in lung function.

RESULTS

The study was terminated after enrollment of 492 patients (75% of intended enrollment; mean duration of exposure to study medication, 34.7 weeks) because an interim analysis indicated a low likelihood of showing efficacy for the end point by the scheduled end of the study. Ambrisentan-treated patients were more likely to meet the prespecified criteria for disease progression (90 [27.4%] vs. 28 [17.2%] patients; P = 0.010; hazard ratio, 1.74 [95% CI, 1.14 to 2.66]). Lung function decline was seen in 55 (16.7%) ambrisentan-treated patients and 19 (11.7%) placebo-treated patients (P = 0.109). Respiratory hospitalizations were seen in 44 (13.4%) and 9 (5.5%) patients in the ambrisentan and placebo groups, respectively (P = 0.007). Twenty-six (7.9%) patients who received ambrisentan and 6 (3.7%) who received placebo died (P = 0.100). Thirty-two (10%) ambrisentan-treated patients and 16 (10%) placebo-treated patients had pulmonary hypertension at baseline, and analysis stratified by the presence of pulmonary hypertension revealed similar results for the primary end point.

LIMITATION

The study was terminated early.

CONCLUSION

Ambrisentan was not effective in treating IPF and may be associated with an increased risk for disease progression and respiratory hospitalizations.

PRIMARY FUNDING SOURCE

Gilead Sciences.

Bayesian probit regression model for the diagnosis of pulmonary fibrosis: proof-of-principle

Background

The accurate diagnosis of idiopathic pulmonary fibrosis (IPF) is a major clinical challenge. We developed a model to diagnose IPF by applying Bayesian probit regression (BPR) modelling to gene expression profiles of whole lung tissue.

Methods

Whole lung tissue was obtained from patients with idiopathic pulmonary fibrosis (IPF) undergoing surgical lung biopsy or lung transplantation. Controls were obtained from normal organ donors. We performed cluster analyses to explore differences in our dataset. No significant difference was found between samples obtained from different lobes of the same patient. A significant difference was found between samples obtained at biopsy versus explant. Following preliminary analysis of the complete dataset, we selected three subsets for the development of diagnostic gene signatures: the first signature was developed from all IPF samples (as compared to controls); the second signature was developed from the subset of IPF samples obtained at biopsy; the third signature was developed from IPF explants. To assess the validity of each signature, we used an independent cohort of IPF and normal samples. Each signature was used to predict phenotype (IPF versus normal) in samples from the validation cohort. We compared the models' predictions to the true phenotype of each validation sample, and then calculated sensitivity, specificity and accuracy.

Results

Surprisingly, we found that all three signatures were reasonably valid predictors of diagnosis, with small differences in test sensitivity, specificity and overall accuracy.

Conclusions

This study represents the first use of BPR on whole lung tissue; previously, BPR was primarily used to develop predictive models for cancer. This also represents the first report of an independently validated IPF gene expression signature. In summary, BPR is a promising tool for the development of gene expression signatures from non-neoplastic lung tissue. In the future, BPR might be used to develop definitive diagnostic gene signatures for IPF, prognostic gene signatures for IPF or gene signatures for other non-neoplastic lung disorders such as bronchiolitis obliterans.

CD86 (B7-2) can function to drive MHC-restricted antigen-specific CTL responses in vivo

Activation of T cells requires both TCR-specific ligation by direct contact with peptide Ag-MHC complexes and coligation of the B7 family of ligands through CD28/CTLA-4 on the T cell surface. We recently reported that coadministration of CD86 cDNA along with DNA encoding HIV-1 Ags i.m. dramatically increased Ag-specific CTL responses. We investigated whether the bone marrow-derived professional APCs or muscle cells were responsible for the enhancement of CTL responses following CD86 coadministration. Accordingly, we analyzed CTL induction in bone marrow chimeras. These chimeras are capable of generating functional viral-specific CTLs against vaccinia virus and therefore represent a useful model system to study APC/T cell function in vivo. In vaccinated chimeras, we observed that only CD86 + Ag + MHC class I results in 1) detectable CTLs following in vitro restimulation, 2) detectable direct CTLs, 3) enhanced IFN-gamma production in an Ag-specific manner, and 4) dramatic tissue invasion of T cells. These results support that CD86 plays a central role in CTL induction in vivo, enabling non-bone marrow-derived cells to prime CTLs, a property previously associated solely with bone marrow-derived APCs.

CD86 (B7-2) Can Function to Drive MHC-Restricted Antigen-Specific CTL Responses In Vivo

Activation of T cells requires both TCR-specific ligation by direct contact with peptide Ag-MHC complexes and coligation of the B7 family of ligands through CD28/CTLA-4 on the T cell surface. We recently reported that coadministration of CD86 cDNA along with DNA encoding HIV-1 Ags i.m. dramatically increased Ag-specific CTL responses. We investigated whether the bone marrow-derived professional APCs or muscle cells were responsible for the enhancement of CTL responses following CD86 coadministration. Accordingly, we analyzed CTL induction in bone marrow chimeras. These chimeras are capable of generating functional viral-specific CTLs against vaccinia virus and therefore represent a useful model system to study APC/T cell function in vivo. In vaccinated chimeras, we observed that only CD86 + Ag + MHC class I results in 1) detectable CTLs following in vitro restimulation, 2) detectable direct CTLs, 3) enhanced IFN-γ production in an Ag-specific manner, and 4) dramatic tissue invasion of T cells. These results support that CD86 plays a central role in CTL induction in vivo, enabling non-bone marrow-derived cells to prime CTLs, a property previously associated solely with bone marrow-derived APCs.

Engineering DNA vaccines via co-delivery of co-stimulatory molecule genes

DNA immunization has been investigated as a potential immunization strategy against infectious diseases and cancer. To enhance a DNA vaccine's ability to induce CTL response in vivo, we co-administered CD80 and CD86 expression cassettes along with HIV-1 immunogens. This manipulation resulted in a dramatic increase in MHC class I-restricted and CD8+ T-cell-dependent CTL responses in both mice and chimpanzees. This strategy of engineering vaccine producing cells to be more efficient T-cell activators could be an important tool for optimizing antigen-specific T-cell-mediated immune responses in the pursuit of more rationally designed vaccines and immune therapies.

Coadministration of IL-12 or IL-10 expression cassettes drives immune responses toward a Th1 phenotype

Cytokines are important regulators of the immune response. They influence immune expression, the development of immunologic memory, and regulation of antigen-specific and nonspecific immune activation as well as allergic responses. In a model system in mice, we have studied the effect of plasmids expressing interleukin (IL)-10 or IL-12 on the modulation of antigen-specific responses. Coadministration of IL-12 or IL-10 genes with DNA immunogens directed the antigen-specific immune response toward a T helper (Th1)-type immunity. In addition to the modulation of antigen-specific immune responses, we studied the induction of delayed-type hypersensitivity (DTH) to contact allergens as an in vivo model of the Th1 response. We found that IL-12 and IL-10 gene-containing plasmids, and not the bacterial plasmid alone, upregulate this response. Our cytokine gene delivery technique demonstrates an important level of control of the magnitude and direction of induced immune responses and could be advantageous in a wide variety of immunotherapeutic strategies.

Ornithine decarboxylase in human brain: influence of aging, regional distribution, and Alzheimer's disease

Although experimental animal data have implicated ornithine decarboxylase, a key regulatory enzyme of polyamine biosynthesis, in brain development and function, little information is available on this enzyme in normal or abnormal human brain. We examined the influence, in autopsied human brain, of postnatal development and aging, regional distribution, and Alzheimer's disease on the activity of ornithine decarboxylase. Consistent with animal data, human brain ornithine decarboxylase activity was highest in the perinatal period, declining sharply (by approximately 60%) during the first year of life to values that remained generally unchanged up to senescence. In adult brain, a moderately heterogeneous regional distribution of enzyme activity was observed, with high levels in the thalamus and occipital cortex and low levels in cerebellar cortex and putamen. In the Alzheimer's disease group, mean ornithine decarboxylase activity was significantly increased in the temporal cortex (+76%), reduced in occipital cortex (-70%), and unchanged in hippocampus and putamen. In contrast, brain enzyme activity was normal in patients with the neurodegenerative disorder spinocerebellar ataxia type I. Our demonstration of ornithine decarboxylase activity in neonatal and adult human brain suggests roles for ornithine decarboxylase in both developing and mature brain function, and we provide further evidence for the involvement of abnormal polyamine system activity in Alzheimer's disease.

Brain S-adenosylmethionine levels are severely decreased in Alzheimer's disease

S-Adenosylmethionine is an essential ubiquitous metabolite central to many biochemical pathways, including transmethylation and polyamine biosynthesis. Reduced CSF S-adenosylmethionine levels in Alzheimer's disease have been reported; however, no information is available regarding the status of S-adenosylmethionine or S-adenosylmethionine-dependent methylation in the brain of patients with this disorder. S-Adenosylmethionine concentrations were measured in postmortem brain of 11 patients with Alzheimer's disease. We found decreased levels of S-adenosylmethionine (-67 to -85%) and its demethylated product S-adenosylhomocysteine (-56 to -79%) in all brain areas examined (cerebral cortical subdivisions, hippocampus, and putamen) as compared with matched controls (n = 14). S-Adenosylmethionine and S-adenosylhomocysteine levels were normal in occipital cortex of patients with idiopathic Parkinson's disease (n = 10), suggesting that the decreased S-adenosylmethionine levels in Alzheimer's disease are not simply a consequence of a chronic, neurodegenerative condition. Reduced S-adenosylmethionine levels could be due to excessive utilization in polyamine biosynthesis. The severe reduction in levels of this essential biochemical substrate would be expected to compromise seriously metabolism and brain function in patients with Alzheimer's disease and may provide the basis for the observations of improved cognition in some Alzheimer's patients following S-adenosylmethionine therapy.

Brain polyamine levels are altered in Alzheimer's disease

Despite considerable evidence implicating polyamines in CNS function, little is known about the status of the polyamine system in normal or abnormal human brain. We measured the levels of the polyamines spermidine, spermine and their precursor putrescine, in cortical and subcortical areas of 12 patients with Alzheimer's disease (AD). As compared with the controls, mean levels of spermidine were markedly and significantly increased (70%) whereas putrescine levels were decreased (28%) in temporal cortex of the AD patients. No other statistically significant changes were observed with the exception of a mean 35% reduction in spermine concentration in occipital cortex. In view of the modulatory effects of polyamines on calcium flux and glutamate receptor function, our data suggest that abnormal polyamine system activity may be involved in the neurodegenerative processes occurring in brain of patients with AD.

Polyamines in human brain: regional distribution and influence of aging

Although much evidence has implicated polyamines in brain development and function, little information is available on these substances in human brain. We examined the influence of regional distribution and aging on putrescine, spermidine, and spermine levels in autopsied human brain. In the adult brain, concentrations of spermidine were the highest, followed by spermine and putrescine. All three polyamines showed a distinct and uneven distribution profile among the 10 examined brain areas. Spermidine levels were especially high in white matter and thalamus (20 and 9.3 nmol/mg of protein, respectively), whereas spermine concentrations were highest in cerebellar cortex (3.4 nmol/mg of protein). High levels of putrescine were observed in cerebral cortices, putamen, and hippocampus (0.7-1.2 nmol/mg or protein), with lowest levels in cerebellum and thalamus (0.3-0.5 nmol/mg of protein). No statistically significant influence of aging (1 day to 103 years; n = 57) on either putrescine or spermine levels in occipital cortex was observed. In contrast, spermidine levels increased markedly from birth, reaching maximal levels at approximately 40 years of age (+228% increase in the mean 41-year-old group vs. 6-week-old group), which were maintained up to senescence. These observations in human brain thus differ from those reported in the rodent, in which levels of all three polyamines show a pronounced postnatal reduction. Our data support the notion that polyamines may have roles in both postnatal brain development and in mature brain function.

The posterior cruciate ligament in total knee surgery. Save, sacrifice, or substitute?

To determine the role of the posterior cruciate ligament in total knee arthroplasty, 242 consecutive primary total knee arthroplasties were included in 1 of 3 sequential groups. Group I included 77 Press Fit Condylar total knee replacements in which the posterior cruciate ligament was completely released from its tibial attachment. In Group II, there were 80 Press Fit Condylar total knee replacements in which the posterior cruciate ligament was retained. Group III consisted of 85 total knee replacements with a posterior cruciate-substituting device (Insall-Burstein II). All patients were observed at least 2 years and evaluated by the Knee Society's Clinical and Functional Scoring System, including a radiographic evaluation. No differences were found between the posterior cruciate ligament sacrificed group and the posterior cruciate ligament preserved group. The 1 significant difference among the 3 groups was in range of motion (ROM). Groups I and II averaged 103 degrees and 104 degrees motion respectively, whereas Group III, the posterior cruciate-substituting group, averaged 112 degrees (p = 0.001). In addition, only in Group III was the lower 95% confidence limit of the mean ROM > 90 degrees. These findings suggest that preserving the posterior cruciate ligament does not consistently lead to improved functional ROM. The posterior cruciate ligament-substituting device historically has demonstrated excellent survivorship and appears to offer greater ROM.

Activity of S-adenosylmethionine decarboxylase, a key regulatory enzyme in polyamine biosynthesis, is increased in epileptogenic human cortex

OBJECTIVE

We measured the activity of S-adenosylmethionine decarboxylase, a key regulatory enzyme of polyamine biosynthesis, in the temporal cortex of patients with epilepsy.

DESIGN

Cortical surgical specimens were obtained following anterior temporal lobe resection for intractable epilepsy. Enzyme activity was compared in nonepileptogenic (n = 16) and epileptogenic (spontaneously discharging; n = 19) regions.

RESULTS

Mean enzyme activity was increased by 44% in samples from epileptogenic cortex compared with samples from nonepileptic regions. The S-adenosylmethionine decarboxylase activity in regions of focal epileptogenic discharges was also increased in five patients compared with paired samples from the nonepileptogenic portion of the same gyrus (+55%).

CONCLUSIONS

Elevated activity of S-adenosylmethionine decarboxylase in regions of active epileptogenic cortical discharges suggests that a disturbance of the polyamine system may be involved in the maintenance of hypersynchronous discharges, perhaps through a modulatory action at the excitatory N-methyl-D-aspartate-preferring glutamate receptor.

S-adenosylmethionine decarboxylase in human brain. Regional distribution and influence of aging

Recent experimental animal studies have implicated brain polyamines as having roles in both brain development and human brain neurodegenerative conditions. In order to provide baseline information, in normal human brain, on one of the key polyamine synthesising enzymes, S-adenosylmethionine decarboxylase (SAMDC), we examined the sensitivity of this enzyme to various cofactors/inhibitors, its regional distribution, and influence of aging in neurologically normal autopsied human brain. SAMDC in normal human brain is similar to that reported in other mammalian cells with regard to substrate affinity (Km = 39 microM), marked sensitivity to putrescine activation (+600%), inhibition (methylglyoxalbisguanidine and MDL 73811), and pH optimum (7.2). There was an uneven distribution of enzyme activity in human brain, and of the 12 brain regions examined, the highest activity was observed in occipital, parietal, frontal and temporal cortices (36-58 pmol/h/mg protein); intermediate activity in cerebellar and insular cortex, pulvinar thalamus, caudate and putamen (12-27 pmol/h/mg protein); and lowest activity in medial-dorsal thalamus, lateral globus pallidus and white matter (< 11 pmol/h/mg protein). The influence of aging (1 day to 103 years) on SAMDC activity in occipital cortex, the region showing the highest activity in human brain (n = 59) was also determined. Enzyme activity increased by approximately 600% from age 6 months to near maximal levels at age 10 years, then remained generally unchanged up to 103 years. Since SAMDC is a key regulatory enzyme in the synthesis of spermidine and spermine, the marked increase in SAMDC activity in the neonate and the sustained high enzyme levels throughout adulthood, imply a role for these polyamines in both development and mature brain function.

Brain S-adenosylmethionine decarboxylase activity is increased in Alzheimer's disease

We measured the activity of S-adenosylmethionine decarboxylase (SAMDC), a key regulatory enzyme of polyamine biosynthesis, in autopsied brain from 13 patients with Alzheimer's Disease (AD). As compared with the controls, mean enzyme activity was increased by 37-96% in all seven examined brain regions with statistically significant increases in temporal cortex (+96%), frontal cortex (+69%) and hippocampus (+90%). The elevated SAMDC may have occurred as part of a generalized polyamine response to brain injury, which has been previously described in experimental animal conditions. Above-normal SAMDC activity implies increased levels/metabolism of spermidine and spermine, two polyamines which are involved in neuronal regeneration, growth factor production, and activation of excitatory N-methyl-D-aspartate preferring glutamate receptors. Our data suggest the involvement of the polyamine system in the brain reparative and/or pathogenetic mechanisms of AD.

Prostaglandin H synthase-dependent formation of the direct-acting mutagen 2-nitro-3-methylimidazo[4,5-f]quinoline (nitro-IQ) from IQ

The mutagenic effects of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) following activation by ram seminal vesicle microsomes (RSVM, a source of prostaglandin H synthase, PHS) were studied in Salmonella typhimurium tester strains possessing elevated levels of acetyl-CoA: arylamine N-acetyltransferase (NAT). The metabolites formed by RSVM were extracted and fractionated by high pressure liquid chromatography (HPLC). One isolable product accounted for most of the direct-acting mutagenicity observed in the extracts. The metabolite was identified as 2-nitro-3-methylimidazo[4,5-f]quinoline (nitro-IQ). Since nitro-IQ is a potent direct-acting mutagen, its role in IQ genotoxicity warrants further study.

Salmonella typhimurium strains expressing human arylamine N-acetyltransferases: metabolism and mutagenic activation of aromatic amines

Epidemiological studies have established the carcinogenic risk of occupational exposure to aromatic amines such as benzidine, beta-naphthylamine, and 4-aminobiphenyl. Metabolic activation of these chemicals to reactive, genotoxic electrophiles, via enzymatic N-oxidation and subsequent conjugation reactions, is necessary for their carcinogenic potential to be realized. Many aromatic amines are mutagenic in prokaryotic test systems, in the presence of exogenous mammalian activating enzymes such as those contained in hepatic 9000 x g supernatant. However, in the Ames (Salmonella typhimurium) assay, induction of mutations by aromatic amines and nitroarenes is also almost completely dependent upon the activity of the endogenous bacterial enzyme, N-acetyltransferase/O-acetyltransferase. The relevance of this assay to the prediction of the carcinogenic potential of aromatic amines in humans is thus restricted by the likelihood that the bacterial and human enzymes possess different substrate specificities. In this paper we report the construction and use of new tester strains of S. typhimurium that express high levels of functional human arylamine N-acetyltransferases, NAT1 and NAT2, retaining characteristic arylamine substrate specificities that are distinct from those of the bacterial enzyme. These new strains support the mutagenic activation of benzidine, 2-aminofluorene and 2-amino-3,4-dimethylimidazo[4,5-f]quinoline in the Ames test and may provide a new tool for evaluating the carcinogenic potential of aromatic amines.