Clinical efficacy of CFTR modulator therapy in people with cystic fibrosis carrying the I1234V mutation.

BACKGROUND: The cystic fibrosis transmembrane conductance regulator (CFTR) mutation I1234V (I1234V, p.Ile1234Val, c.3700A>G), is a missense-mutation that creates a cryptic splice site, with the formation of a protein lacking 6 amino acids, that is misfolded and misprocessed. The in vitro effects of CFTR modulator (CFTRm) therapies on human bronchial cell models and intestinal organoids carrying this mutation are conflicting. The aim of this study was therefore to explore the clinical efficacy of CFTRm in people with cystic fibrosis (pwCF) carrying this mutation. METHODS: This was a retrospective descriptive study of the clinical records of homozygous and compound heterozygous (none F508del) pwCF, for the I1234V mutation, that received CFTRm. Parameters explored were body mass index (BMI), forced expiratory volume in one second percent predicted (FEV1%), lung clearance index (LCI) and quantitative sweat chloride measurements. RESULTS: Mean age was 38.6 ± 14 years (range 21-60). Two subjects were homozygous and five compound heterozygous, with minimal function mutations. Four were pancreatic insufficient and three pancreatic sufficient. The two homozygous subjects received Tezacaftor/Ivacaftor, the remaining Elexacaftor/Tezacaftor/Ivacaftor (ETI); treatment ranged from 6 to 12 months. Mean BMI score increased from 21.7 ± 1.3 to 23.6 ± 2.1 kg/m2 (p = 0.04); FEV1(%pred) increased by 20.14±10.2while mean change in FEV1 in the year prior to CFTRm initiation was -0.14±1.18 (p = 0.0001). Additionally, LCI 2.5% decreased from 18.7 to 14.5 (p = 0.07); sweat chloride decreased from 116±10 to 90±17 mEq/L (p = 0.017) and chronic pseudomonas airway infection was eradicated in one subject. CONCLUSIONS: This study supports a clinical benefit for CFTRm therapy in pwCF carrying the I1234V mutation.

Pediatric splenic infarction: Assessment of associated clinical conditions and outcome.

Pediatric splenic infarction (SI) is rare yet clinically significant. Publications regarding this complication are mostly limited to case reports. This is a retrospective study examining SI etiology, clinical presentation, management, and outcomes among children. Twenty-two patients (median age: 7.9 years) were included, mostly with pre-existing hematological diseases. Splenomegaly (72%), thrombocytopenia, and anemia were common. Most of the patients did not receive antithrombotic therapy yet only two patients experienced recurrences. During follow up 36% of patients died, however no fatalities were attributed to thrombotic or bleeding complications.

Congenital Central Hypoventilation Syndrome in Israel-Novel Findings from a New National Center.

BACKGROUND: Congenital central hypoventilation syndrome (CCHS) is a rare autosomal-dominant disorder of the autonomic nervous system that results from mutations in the PHOX2B gene. A national CCHS center was founded in Israel in 2018. Unique new findings were observed. METHODS: All 27 CCHS patients in Israel were contacted and followed. Novel findings were observed. RESULTS: The prevalence of new CCHS cases was almost twice higher compared to other countries. The most common mutations in our cohort were polyalanine repeat mutations (PARM) 20/25, 20/26, 20/27 (combined = 85% of cases). Two patients showed unique recessive inheritance while their heterozygotes family members were asymptomatic. A right-sided cardio-neuromodulation was performed on an eight-year-old boy for recurrent asystoles by ablating the parasympathetic ganglionated plexi using radiofrequency (RF) energy. Over 36 months' follow-up with an implantable loop-recorder, no bradycardias/pauses events were observed. A cardiac pacemaker was avoided. CONCLUSIONS: A significant benefit and new information arise from a nationwide expert CCHS center for both clinical and basic purposes. The incidence of CCHS in some populations may be increased. Asymptomatic NPARM mutations may be much more common in the general population, leading to an autosomal recessive presentation of CCHS. RF cardio-neuromodulation offers a novel approach to children avoiding the need for permanent pacemaker implantation.

Spontaneous pneumothorax-When do we need to intervene?

BACKGROUND: Pneumothorax can be classified as traumatic, iatrogenic or spontaneous (SP), which can be subdivided into primary spontaneous pneumothorax (PSP), a condition without preexisting lung disease, or secondary spontaneous pneumothorax (SSP) a complication of a preexisting lung disease. Recurrence rate of PSP is 30% whereas for SSP rate is unknown. This article explores the experience of a tertiary center over 20 years. METHODS: A retrospective case review of patients hospitalized with pneumothorax to investigate the natural history and treatment of SP in a young population in a single tertiary center was conducted. A search of the digital archive (going back to 01/01/1995) of Sheba Medical Center identified hospitalized patients below the age of 40. RESULTS: The database was composed of the records of 750 patients (612 males, 138 females) who were hospitalized. The recurrence risk for SP after nonoperative treatment was significantly higher. Women were found to have an increased risk of SSP when having SP (OR 2.78). Asthma was the most prevalent disease causing SSP in young people. CONCLUSIONS: In this large cohort, we found that operative procedure has clear protective effect from recurrence in SP, so surgery should be positively considered when treating SP in hospitalized patients. Among young people and particularly in pediatric patients, when females have a SP, we strongly recommend looking for primary lung disease. More studies are needed to determine the risk factors and produce clear guidelines regarding surgery as first treatment.

Advanced Lung Disease in Patients with Cystic Fibrosis Is Associated with Low Diffusion capacity.

BACKGROUND: The single-breath diffusing capacity of the lungs (DLCOSB) test measures the extent to which carbon monoxide (CO) passes from the lung air sacs into the blood. The accessible alveolar volume (VASB) is measured by inert gas during a 10-second period. The single-breath transfer coefficient of the lung for carbon monoxide (KCOSB) is the DLCOSB divided by VASB. Cystic fibrosis (CF) disease comprises progressive airway obstruction with bronchiectasis and parenchyma fibrosis. Yet, the KCOSB appears insignificant in the assessment of pulmonary function in CF. OBJECTIVES: To challenge the precision of normal KCOSB in CF. METHODS: The authors collected pulmonary function tests (PFT) data from 74 confirmed CF patients (mean age 26 ± 10 years) with various levels of pulmonary disease severity. Tests included spirometry, DLCOBP, and body plethysmography (BP). Anatomical dead space was calculated by deducting anatomical dead space from total lung capacity TLC(BP) to establish alveolar volume (VABP) and to determine KCOBP. We also included individual data of arterial pCO2 blood-gas level. RESULTS: KCOSB values were normal or higher in most patients, regardless of patient FEV1 value (R2 = 0.2204; P < 0.02). In contrast, the measurements of KCOBP were low corresponding with low FEV1 values, and negatively correlated with the elevation of trapped air and pCO2 levels (R2 = 0.1383; P = 0.0133, P > 0.05, respectively). CONCLUSIONS: The 10- second perfusion time of the inert gas during DLCOSB represent the communicative alveolar volume in CF patients with advanced pulmonary disease. The findings justify the use of DLCOSB with the deterioration of FEV1 and elevation of pCO2 levels.

Phenotypic and molecular characteristics of CF patients carrying the I1234V mutation.

BACKGROUND: The Mutation I1234V is a CF causing mutation; however the mechanisms leading to loss of function are not fully understood. In this study, we aimed to characterize phenotypically individuals with the I1234V variant, and to gain a structural point of view of the mutant CFTR using computational studies. METHODS: We conducted a retrospective descriptive study, reviewing the clinical records of 9 Israeli patients. The study was designed to include patients either homozygous or compound heterozygous for the I1234V mutation. For a comparison we analyzed clinical data of 12 patients homozygous for the F508del mutation. Computer models were constructed for I1234V, 1234-1239del and wild type CFTR. RESULTS: Mean FEV1 was 73.8 ± 21% predicted with an average annual rate of decline of 1%. When compared to patients homozygous for F508del the mean annual values of FEV1% predicted during the 6 years of data collection ranged from 51 to 58 ± 22-30 in the F508del group versus 76-82 ± 14-19 in the I1234V group (p < 0.05). Structural models did not demonstrate noticeable differences between the three simulated constructs. Although the mutation resides in the NBD2, no interference with ATP binding was detected. DISCUSSION: This study describes phenotypically patients carrying the I1234V mutation. Compared to patients homozygous for F508del, these patients present with more favorable outcome. Structural models show high similarity between the static and dynamics pictures obtained for both the mutated and the WT-CFTR; however this model does not explore the folding process and therefore may strengthen the notion of a misfolding mutation.

Resting Energy Expenditure in Patients With Familial Dysautonomia: A Preliminary Study.

OBJECTIVES: Familial dysautonomia (FD) is a rare hereditary sensory and autonomic neuropathy characterized by chronic lung disease and cyclic vomiting due to hyper-adrenergic crises. Most FD patients are in a depleted nutritional state; however, the phenotype of the disease is quite different between patients, as for the severity of lung disease and the intensity and frequency of these pathognomonic crises. In this study we wanted to investigate whether resting energy expenditure (REE) levels are increased in this population, and if correlations exist between REE levels and phenotype severity. METHODS: Data was collected from 12 FD patients (6/6 m/f). REE measurements were conducted by indirect calorimeter. Measured REE % predicted were correlated with pulmonary function, severity of the scoliosis, serum C-reactive protein, yearly frequency of hyperadrenergic crisis, hospital admissions and the use of nocturnal noninvasive positive pressure ventilation. RESULTS: Mean REE was 112 ±13% predicted with 50% being in a hypermetabolic state (REE/HB > 110%). Body mass index (BMI) was below normal range in 75% of patients, and reduced energy intake was also decreased in 75%. No significant correlations to disease severity factors were found. When dividing the subjects to REE levels above or below 125% predicted, Patients with REE above 125% predicted presented with significantly lower inspiratory capacity (42.7% predicted vs 62.8% predicted; P = 0.04). CONCLUSIONS: Hypermetabolic state was described in 50% of FD patients. The Low BMI is explained by combination of relative anorexia and increased REE. The REE levels are related to the underling respiratory disease.

Omalizumab in allergic bronchopulmonary aspergillosis in patients with cystic fibrosis.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is a condition characterized by a Th2 response, serum eosinophilia, and increased total serum IgE to Aspergillus fumigatus. ABPA occurs in cystic fibrosis (CF) and asthma. Omalizumab is a humanized recombinant monoclonal antibody against IgE. Previous studies reported borderline results when treating ABPA with omalizumab. METHODS: A retrospective study to investigate the efficacy of omalizumab in the treatment of ABPA in CF patients was conducted at 3 CF centers in Israel and Belgium. Data were obtained from the digital archive. We measured 4 outcome parameters: forced expiratory volume in 1 second, body mass index, pulmonary exacerbations, and steroid sparing. RESULTS: The database was composed on the records of 9 patients. None of the outcome parameters showed any improvement. A favorable outcome was observed in patients with higher levels of posttreatment total IgE than those with lower levels. CF-related diabetes and male gender showed trends for poorer outcomes. CONCLUSION: No benefits were detected on treating ABPA in CF with omlaizumb. Monitoring the total IgE was not helpful. A prospective randomized double-blind study is needed.

Ivacaftor for the p.Ser549Arg (S549R) gating mutation - The Israeli experience.

BACKGROUND: Ivacaftor is a drug that increases the probability of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel remaining open. Information about the efficacy of ivacaftor in patients carrying the rare p.Ser549Arg (S549R) CFTR mutation is sparse. AIM: Efficacy of ivacaftor treatment in patients carrying the p.Ser549Arg (S549R) CFTR mutation. METHODS: Data obtained from CF patients receiving ivacaftor for one year. RESULTS: Eight CF patients, mean age 21 ± 10 years, received ivacaftor. After one year, significant improvement was found in FEV1, increasing from 74% to 88% (p < 0.001), FVC, 89% to 101% (p = 0.019), and FEF25-75, 59%-76% (p = 0.019). Sweat chloride concentration decreased from 116 ± 8 mmol/L to 51 ± 17 mmol/L (p < 0.001), and BMI increased from 20 ± 3 to 22 ± 4 (p = 0.003). Glucose tolerance improved in five patients. There was no significant change in bacterial colonization. CONCLUSIONS: Ivacaftor therapy resulted in significant clinical improvement in patients carrying the p.Ser549Arg (S549R) CFTR mutation.