Lung structure and function similarities between primary ciliary dyskinesia and mild cystic fibrosis: a pilot study

Background

Primary ciliary dyskinesia (PCD) and cystic fibrosis (CF) are increasingly compared. There are no chest magnetic resonance imaging (MRI) comparative studies of PCD and CF. We assessed clinical, functional, microbiological and MRI findings in PCD and mild CF patients in order to evaluate different expression of lung disease.

Methods

Twenty PCD (15.1 years) and 20 CF subjects with mild respiratory impairment (16 years, 70% with pancreatic insufficiency) underwent MRI, spirometry, and sputum cultures when clinically stable. MRI was scored using the modified Helbich system.

Results

PCD was diagnosed later than CF (9.9 versus 0.6 years, p = 0.03), despite earlier symptoms (0.1 versus 0.6 years, p = 0.02). In the year preceding the study, patients from both groups underwent two systemic antibiotic courses (p = 0.48). MRI total scores were 11.6 ± 0.7 and 9.1 ± 1 in PCD and CF, respectively. FEV₁ and FVC Z-scores were −1.75 (range, −4.6–0.7) and −0.6 (−3.9–1.8) in PCD, and −0.9 (range, −5.4–2.3) and −0.3 (−3.4–2.5) in CF, respectively. No difference was found between lung function or structure, despite a higher MRI subscore of collapse/consolidation in PCD versus CF (1.6 ± 0.1 and 0.6 ± 0.2, p < 0.001). These findings were confirmed after data-control for diagnostic delay. Pseudomonas aeruginosa and Staphylococcus aureus were more frequent in CF than in PCD (p = 0.05 and p = 0.003, respectively).

Conclusions

MRI is a valuable radiation-free tool for comparative PCD and CF lung disease assessment. Patients with PCD may exhibit similar MRI and lung function changes as CF subjects with mild pulmonary disease. Delay in PCD diagnosis is unlikely the only determinant of similarities.

Electronic supplementary material

The online version of this article (doi:10.1186/s13052-017-0351-2) contains supplementary material, which is available to authorized users.

Reduced absorption and enhanced synthesis of cholesterol in patients with cystic fibrosis: a preliminary study of plasma sterols

BACKGROUND

Low cholesterol is typically observed in the plasma of patients with cystic fibrosis (CF) contrasting with the subcellular accumulation of cholesterol demonstrated in CF cells and in mice models. However, the homeostasis of cholesterol has not been well investigated in patients with CF.

METHODS

We studied the plasma of 26 patients with CF and 33 unaffected controls campesterol and β-sitosterol as markers of intestinal absorption and lathosterol as a marker of de novo cholesterol biosynthesis by gas chromatography (GC-FID and GC-MS).

RESULTS

Plasma campesterol and β-sitosterol results were significantly (p=0.01) lower while plasma lathosterol was significantly higher (p=0.001) in patients with CF as compared to control subjects. Plasma cholesterol results were significantly lower (p=0.01) in CF patients.

CONCLUSIONS

Our data suggest that the impaired intestinal absorption of exogenous sterols in patients with CF stimulates the endogenous synthesis of cholesterol, but the levels of total cholesterol in plasma remain lower. This may be due to the CFTR dysfunction that reduces cholesterol blood excretion causing the accumulation of cholesterol in liver cells and in other tissues contributing to trigger CF chronic inflammation.

Cysteamine re-establishes the clearance of Pseudomonas aeruginosa by macrophages bearing the cystic fibrosis-relevant F508del-CFTR mutation

Cystic fibrosis (CF), the most common lethal monogenic disease in Caucasians, is characterized by recurrent bacterial infections and colonization, mainly by Pseudomonas aeruginosa, resulting in unresolved airway inflammation. CF is caused by mutations in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which functions as a chloride channel in epithelial cells, macrophages, and other cell types. Impaired bacterial handling by macrophages is a feature of CF airways, although it is still debated how defective CFTR impairs bacterial killing. Recent evidence indicates that a defective autophagy in CF macrophages leads to alterations of bacterial clearance upon infection. Here we use bone marrow-derived macrophages from transgenic mice to provide the genetic proof that defective CFTR compromises both uptake and clearance of internalized Pseudomonas aeruginosa. We demonstrate that the proteostasis regulator cysteamine, which rescues the function of the most common F508del-CFTR mutant and hence reduces lung inflammation in CF patients, can also repair the defects of CF macrophages, thus restoring both bacterial internalization and clearance through a process that involves upregulation of the pro-autophagic protein Beclin 1 and re-establishment of the autophagic pathway. Altogether these results indicate that cysteamine restores the function of several distinct cell types, including that of macrophages, which might contribute to its beneficial effects on CF.

Metabolic interactions between cysteamine and epigallocatechin gallate

Phase II clinical trials indicate that the combination of cysteamine plus epigallocatechin gallate (EGCG) is effective against cystic fibrosis in patients bearing the most frequent etiological mutation (CFTRΔF508). Here, we investigated the interaction between both agents on cultured respiratory epithelia cells from normal and CFTRΔF508-mutated donors. We observed that the combination of both agents affected metabolic circuits (and in particular the tricarboxylic acid cycle) in a unique way and that cysteamine plus EGCG reduced cytoplasmic protein acetylation more than each of the 2 components alone. In a cell-free system, protein cross-linking activity of EGCG was suppressed by cysteamine. Finally, EGCG was able to enhance the conversion of cysteamine into taurine in metabolic flux experiments. Altogether, these results indicate that multiple pharmacological interactions occur between cysteamine and EGCG, suggesting that they contribute to the unique synergy of both agents in restoring the function of mutated CFTRΔF508.

Genotype-phenotype correlation and functional studies in patients with cystic fibrosis bearing CFTR complex alleles

BACKGROUND

The effect of complex alleles in cystic fibrosis (CF) is poorly defined for the lack of functional studies.

OBJECTIVES

To describe the genotype-phenotype correlation and the results of either in vitro and ex vivo studies performed on nasal epithelial cells (NEC) in a cohort of patients with CF carrying cystic fibrosis transmembrane conductance regulator (CFTR) complex alleles.

METHODS

We studied 70 homozygous, compound heterozygous or heterozygous for CFTR mutations: p.[Arg74Trp;Val201Met;Asp1270Asn], n=8; p.[Ile148Thr;Ile1023_Val1024del], n=5; p.[Arg117Leu;Leu997Phe], n=6; c.[1210-34TG[12];1210-12T[5];2930C>T], n=3; p.[Arg74Trp;Asp1270Asn], n=4; p.Asp1270Asn, n=2; p.Ile148Thr, n=6; p.Leu997Phe, n=36. In 39 patients, we analysed the CFTR gating activity on NEC in comparison with patients with CF (n=8) and carriers (n=4). Finally, we analysed in vitro the p.[Arg74Trp;Val201Met;Asp1270Asn] complex allele.

RESULTS

The p.[Ile148Thr;Ile1023_Val1024del] caused severe CF in five compound heterozygous with a class I-II mutation. Their CFTR activity on NEC was comparable with patients with two class I-II mutations (mean 7.3% vs 6.9%). The p.[Arg74Trp;Asp1270Asn] and the p.Asp1270Asn have scarce functional effects, while p.[Arg74Trp;Val201Met;Asp1270Asn] caused mild CF in four of five subjects carrying a class I-II mutation in trans, or CFTR-related disorders (CFTR-RD) in three having in trans a class IV-V mutation. The p.[Arg74Trp;Val201Met;Asp1270Asn] causes significantly (p<0.001) higher CFTR activity compared with compound heterozygous for class I-II mutations. Furthermore, five of six compounds heterozygous with the p.[Arg117Leu;Leu997Phe] had mild CF, whereas the p.Leu997Phe, in trans with a class I-II CFTR mutation, caused CFTR-RD or a healthy status (CFTR activity: 21.3-36.9%). Finally, compounds heterozygous for the c.[1210-34TG[12];1210-12T[5];2930C>T] and a class I-II mutation had mild CF or CFTR-RD (gating activity: 18.5-19.0%).

CONCLUSIONS

The effect of complex alleles partially depends on the mutation in trans. Although larger studies are necessary, the CFTR activity on NEC is a rapid contributory tool to classify patients with CFTR dysfunction.

A novel treatment of cystic fibrosis acting on-target: cysteamine plus epigallocatechin gallate for the autophagy-dependent rescue of class II-mutated CFTR

This corrects the article DOI: 10.1038/cdd.2016.22.

A novel treatment of cystic fibrosis acting on-target: cysteamine plus epigallocatechin gallate for the autophagy-dependent rescue of class II-mutated CFTR

We previously reported that the combination of two safe proteostasis regulators, cysteamine and epigallocatechin gallate (EGCG), can be used to improve deficient expression of the cystic fibrosis transmembrane conductance regulator (CFTR) in patients homozygous for the CFTR Phe508del mutation. Here we provide the proof-of-concept that this combination treatment restored CFTR function and reduced lung inflammation (P<0.001) in Phe508del/Phe508del or Phe508del/null-Cftr (but not in Cftr-null mice), provided that such mice were autophagy-competent. Primary nasal cells from patients bearing different class II CFTR mutations, either in homozygous or compound heterozygous form, responded to the treatment in vitro. We assessed individual responses to cysteamine plus EGCG in a single-centre, open-label phase-2 trial. The combination treatment decreased sweat chloride from baseline, increased both CFTR protein and function in nasal cells, restored autophagy in such cells, decreased CXCL8 and TNF-α in the sputum, and tended to improve respiratory function. These positive effects were particularly strong in patients carrying Phe508del CFTR mutations in homozygosity or heterozygosity. However, a fraction of patients bearing other CFTR mutations failed to respond to therapy. Importantly, the same patients whose primary nasal brushed cells did not respond to cysteamine plus EGCG in vitro also exhibited deficient therapeutic responses in vivo. Altogether, these results suggest that the combination treatment of cysteamine plus EGCG acts 'on-target' because it can only rescue CFTR function when autophagy is functional (in mice) and improves CFTR function when a rescuable protein is expressed (in mice and men). These results should spur the further clinical development of the combination treatment.

Manipulating proteostasis to repair the F508del-CFTR defect in cystic fibrosis

Cystic fibrosis (CF) is a lethal monogenic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that entails the (diagnostic) increase in sweat electrolyte concentrations, progressive lung disease with chronic inflammation and recurrent bacterial infections, pancreatic insufficiency, and male infertility. Therapies aimed at restoring the CFTR defect have emerged. Thus, a small molecule which facilitates chloride channel opening, the potentiator Ivacaftor, has been approved for the treatment of CF patients bearing a particular class of rare CFTR mutations. However, small molecules that directly target the most common misfolded CFTR mutant, F508del, and improve its intracellular trafficking in vitro, have been less effective than expected when tested in CF patients, even in combination with Ivacaftor. Thus, new strategies are required to circumvent the F508del-CFTR defect. Airway and intestinal epithelial cells from CF patients bearing the F508del-CFTR mutation exhibit an impressive derangement of cellular proteostasis, with oxidative stress, overactivation of the tissue transglutaminase (TG2), and disabled autophagy. Proteostasis regulators such as cysteamine can rescue and stabilize a functional F508del-CFTR protein through suppressing TG2 activation and restoring autophagy in vivo in F508del-CFTR homozygous mice, in vitro in CF patient-derived cell lines, ex vivo in freshly collected primary patient’s nasal cells, as well as in a pilot clinical trial involving homozygous F508del-CFTR patients. Here, we discuss how the therapeutic normalization of defective proteostasis can be harnessed for the treatment of CF patients with the F508del-CFTR mutation.

Restoration of CFTR function in patients with cystic fibrosis carrying the F508del-CFTR mutation

Restoration of BECN1/Beclin 1-dependent autophagy and depletion of SQSTM1/p62 by genetic manipulation or autophagy-stimulatory proteostasis regulators, such as cystamine, have positive effects on mouse models of human cystic fibrosis (CF). These measures rescue the functional expression of the most frequent pathogenic CFTR mutant, F508del, at the respiratory epithelial surface and reduce lung inflammation in Cftr^F508del homozygous mice. Cysteamine, the reduced form of cystamine, is an FDA-approved drug. Here, we report that oral treatment with cysteamine greatly reduces the mortality rate and improves the phenotype of newborn mice bearing the F508del-CFTR mutation. Cysteamine was also able to increase the plasma membrane expression of the F508del-CFTR protein in nasal epithelial cells from F508del homozygous CF patients, and these effects persisted for 24 h after cysteamine withdrawal. Importantly, this cysteamine effect after washout was further sustained by the sequential administration of epigallocatechin gallate (EGCG), a green tea flavonoid, both in vivo, in mice, and in vitro, in primary epithelial cells from CF patients. In a pilot clinical trial involving 10 F508del-CFTR homozygous CF patients, the combination of cysteamine and EGCG restored BECN1, reduced SQSTM1 levels and improved CFTR function from nasal epithelial cells in vivo, correlating with a decrease of chloride concentrations in sweat, as well as with a reduction of the abundance of TNF/TNF-alpha (tumor necrosis factor) and CXCL8 (chemokine [C-X-C motif] ligand 8) transcripts in nasal brushing and TNF and CXCL8 protein levels in the sputum. Altogether, these results suggest that optimal schedules of cysteamine plus EGCG might be used for the treatment of CF caused by the F508del-CFTR mutation.

Screening of glucose metabolism derangements in pediatric cystic fibrosis patients: how, when, why

Diabetes mellitus is the most common comorbidity in cystic fibrosis (CF), occurring in a variable number of children and adolescents. Glucose metabolism derangements (GMDs) are responsible for a negative impact on the general health status of CF patients. Screening of GMDs is important since the youngest age and should be performed by means of OGTT, including its intermediate times, that could detect other non-traditional GMDs. Insulin treatment, administered before overt diabetes, could be beneficial in reducing the number of pulmonary infections, in improving both pulmonary function and nutritional status. Early screening of GMDs in pediatric age can exert an important preventing role regarding all aspects of health status of patients with CF.

Shwachman-Diamond syndrome with autoimmune-like liver disease and enteropathy mimicking celiac disease

Liver abnormalities that normalize during infancy as well an enteropathy are reported in Shwachman-Diamond syndrome (SDS). The pathogenesis of both conditions is unknown. We report two SDS cases with autoimmune-like (antismooth muscle and/or antinuclear antibody positivity) liver disease and antigliadin antibody positive inflammatory enteropathy. Hypertransaminasemia did not resolve after immunosuppressive therapy and/or a gluten-free diet. These transient autoimmune phenomena and gut-liver axis perturbations may have played a role in transient SDS hepatopathy and enteropathy. Our report may stimulate other studies to define the relationship between the SDS genetic defect and intestinal permeability as the pathogenic mechanism underlying SDS related liver and intestinal inflammation.

Simple diagnosis of benign acute childhood myositis: Lessons from a case report

Acute muscle pain and walking difficulty are symptoms compatible with both benign and severe degenerative diseases. As a consequence, in some cases invasive tests and hospitalizations are improperly scheduled. We report the case of a 7-year-old child suffering from acute calf pain and abnormal gait following flu-like symptoms. A review of the literature will be helpful to better define differential diagnosis in cases of muscle pain in children. Daily physical examination and urine dipstick are sufficient to confirm the diagnosis of benign acute childhood myositis (BACM) during the acute phase, to promptly detect severe complications and to rule out degenerative diseases. Children with BACM do not require hospitalization, medical interventions or long-term follow-up.

Clinical expression of patients with the D1152H CFTR mutation

BACKGROUND

Discordant results were reported on the clinical expression of subjects bearing the D1152H CFTR mutation, and also for the small number of cases reported so far.

METHODS

A retrospective review of clinical, genetic and biochemical data was performed from individuals homozygous or compound heterozygous for the D1152H mutation followed in 12 Italian cystic fibrosis (CF) centers.

RESULTS

89 subjects carrying at least D1152H on one allele were identified. 7 homozygous patients had very mild clinical expression. Over half of the 74 subjects compound heterozygous for D1152H and a I-II-III class mutation had borderline or pathological sweat test and respiratory or gastrointestinal symptoms; one third had pulmonary bacteria colonization and 10/74 cases had complications (i.e. diabetes, allergic bronchopulmonary aspergillosis, and hemoptysis). However, their clinical expression was less severe as compared to a group of CF patients homozygous for the F508del mutation. Finally, 8 subjects compound heterozygous for D1152H and a IV-V class mutation showed very mild disease.

CONCLUSIONS

The natural history of subjects bearing the D1152H mutation is widely heterogeneous and is influenced by the mutation in trans.

Can continuous subcutaneous insulin infusion improve health-related quality of life in patients with Shwachman-Bodian-Diamond syndrome and diabetes?

We report the first case of the use of continuous subcutaneous insulin infusion (CSII) in a patient with Shwachman-Bodian-Diamond syndrome (SBDS) and diabetes. An Italian boy received diagnosis of SBDS at the age of 7 months (SBDS gene mutation: c.183-184TA → CT and c.258 + 2 T → C in compound heterozygous). The patient presented an impaired psychosocial functioning with difficulties in mental health, body pain experiences, attention deficit disorder, somatic complaints, behavioral and social problems. Total Intelligence Quotient (T-IQ) was within the normal range for age (T-IQ = 109). The patient developed clinical diabetes at the age of 13 years (glycemia 282 mg/dL at 120 min of oral glucose tolerance test, glycosylated hemoglobin level of 7.5%, anti-β-cell antibodies negative; glucagon test yielding a C peptide level at zero-time of 1.5 ng/mL and at 6 min of 2.0 ng/mL). Multiple daily injection therapy with insulin was started. Nevertheless, because of a relevant needle phobia and the recurrent hypoglycemia due to poor nutrition secondary to depression, after 3 years the patient started CSII. After 12 months a new evaluation showed (1) better social adaptation, (2) meliorated self-esteem and self-efficacy, (3) reduced psychosocial suffering, and (4) improved health-related quality of life, assessed by the Pediatric Quality of Life Inventory version 3.0 Diabetes Module. Thus CSII seems to be crucial to improve health-related quality of life in patients affected by diabetes and genetic disorders.

Identification of Inquilinus limosus in cystic fibrosis: a first report in Italy

Cystic fibrosis is a genetic disorder associated with a polymicrobial lung infection where classical pathogens and newly identified bacteria may interact. Inquilinus limosus is an a-proteobacterium recently isolated in the airways of cystic fibrosis patient. We report the first case in Italy of I.limosus isolation from the sputum sample of a cystic fibrosis patient. The patient is a 20-years-old man with cystic fibrosis, regularly attending the Regional Care Center for Cystic Fibrosis at the Federico II University Hospital of Naples. Microbiological culture methods detected a mu- coid gram negative bacillus in the patient's sputum sample. The isolate exhibited a distinct antimicrobial suscep- tibility profile with a high MIC for several drugs. The MALDI-TOF mass spectrometry analysis indicated the bac- terium isolated as I. limosus, confirmed by 16s rDNA sequence analysis. The described clinical case demonstrates how the bacterial biodiversity in the airways of cystic fibrosis patients is still underestimated. Cystic fibrosis lung represents an ecological niche suitable for growth of a wide variety of unusual bacteria not commonly associated with human diseases, such as I. limosus. Therefore further studies are needed to evaluate the epidemiology and clinical implications of I. limosus in the physiopathology of cystic fibrosis lung infection.

Cystic fibrosis database (CFDB): a new web-based tool for cystic fibrosis specialists

In order to help specialists involved in CF care and clinical research to know the current best evidence about clinical effectiveness of interventions in CF, we designed and developed a web-based, free access tool called "CFDB"--Cystic Fibrosis DataBase (www.inetflow.it/CFDB). The database was built by searching in Medline, Embase, Cochrane Library and worldwide trials registries all studies involving clinical interventions in CF. The tool lets the user define queries starting from one or more types of pathological conditions and one or more interventions. The output of the queries is structured in three levels: (1) how many and which studies deal with the conditions formulated in the query; (2) which are the main results of these studies; (3) a critical summary of the literature related to the query. This tool, providing a quick overview of the available evidence in clinical research in CF, may help clinical decision making, designing of new trials and building guidelines.

Primary herpes virus infection and ischemic stroke in childhood: a new association?

We describe, to our knowledge, the first case of arterial ischemic stroke after primary herpes simplex virus type 1 (HSV1) infection in a previously healthy child, without signs of encephalitis. A 10-year-old previously healthy girl was admitted to our hospital with acute left-sided hemiparesis which involved the lower half of her face. Submandibular lymphadenitis and oral vesicular lesions were present. MRI confirmed the suspicion of an acute ischemic stroke. Immunoglobulin M antibodies to HSV1 were detected. Cerebrospinal fluid polymerase chain reaction for herpes virus was negative. She was treated with aspirin (3mg/kg) and intravenous acyclovir (10mg/kg every 8 hours) for 21 days. Immunoglobulin G antibodies to HSV1 appeared 16 days after admission. Twelve months after her hospitalization the patient's examination was normal. Stroke should be considered a possible complication of HSV1 primary infection. Guidelines for the management of acute stroke in children are needed.