La mucoviscidose en 2008

Evolution of sinonasal clinical features in children with cystic fibrosis

OBJECTIVE

to assess the evolution of sinonasal manifestations in children with cystic fibrosis, since the improvement of their prognosis over the last decades.

METHODS

an observational, monocentric study with a retrospective cohort. We included 173 children (from 4 to 18 years old) with cystic fibrosis followed at the pediatric cystic fibrosis center of lyon, france. We collected respiratory, infectious and nutritional data, sinonasal complaints and physical examination at the onset of sinonasal symptoms (t-0), at the most severe of evolution (t-max) and at the end of followup (t-end).

RESULTS

sinonasal symptomatology appeared early around 5.4 years old, then rapidly reached the maximum at 6.9 years and finally improved during childhood (p < 0.0001), reaching scores at t-end significantly better than at t-0 (p < 0.0001). This evolution was significant for nasal obstruction, rhinorrhea and snoring. The other symptoms were rarer, with no significant 38,7% at t-max (p < 0.0001), and 29,5% at t-end (p = 0.52). The lildholdt score, turbinate hypertrophy and medial bulging of medial wall of the maxillary sinus followed the same evolution (p < 0.003). There was no association between sinonasal evolution and cystic fibrosis disease at infectious, respiratory or nutritional level.

CONCLUSION

it is the only recent study evaluating the evolution of each sinonasal manifestations in children with cystic fibrosis. Rhinosinusitis improved during childhood, reaching better scores than at the beginning of management. This particular improvement may be related to good effectiveness to ent management, but also to a positive effect of nasal cavity growth, independently to extra-ent manifestations.

Nutritional status and muscle dysfunction in chronic respiratory diseases: stable phase versus acute exacerbations

Nutritional abnormalities are frequent in different chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD), bronchiectasis, cystic fibrosis (CF), interstitial fibrosis and lung cancer, having important clinical consequences. However, nutritional abnormalities often remained underdiagnosed due to the relative lack of awareness of health professionals. Therefore, systematic anthropometry or even better, assessment of body composition, should be performed in all patients with chronic respiratory conditions, especially following exacerbation periods when malnutrition becomes more accentuated. Nutritional abnormalities very often include the loss of muscle mass, which is an important factor for the occurrence of muscle dysfunction. The latter can be easily detected with the specific assessment of muscle strength and endurance, and also negatively influences patients' quality of life and prognosis. Both nutritional abnormalities and muscle dysfunction result from the interaction of several factors, including tobacco smoking, low physical activity-sedentarism, systemic inflammation and the imbalance between energy supply and requirements, which essentially lead to a negative balance between protein breakdown and synthesis. Therapeutic approaches include improvements in lifestyle, nutritional supplementation and training. Anabolic drugs may be administered in some cases.

Targeted CFTR gene disruption with zinc-finger nucleases in human intestinal epithelial cells induces oxidative stress and inflammation

Cystic fibrosis (CF) is a multisystemic pathology caused by mutations of the CF transmembrane conductance regulator (CFTR) gene.

OBJECTIVES

As the intestine harbors the greatest number of CFTR transcripts after birth and since CFTR plays a role in glutathione transport, we hypothesized that CFTR deletion might produce oxidative stress (OxS) and inflammation in CF intestinal epithelial cell.

METHODS

CFTR gene was abrogated in Caco-2/15 enterocytes through the zinc-finger nuclease system. Their oxidative and inflammatory characteristics were appreciated under basal conditions and after the treatment with the pro-oxidant iron-ascorbate (Fe/Asc) complex and pro-inflammatory lipopolysaccharide (LPS).

RESULTS

Intestinal epithelial cells with CFTR knockout spontaneously exhibited an increased lipid peroxidation level, reflected by malondialdehyde overproduction and reduced antioxidant defense characterized by low enzymatic activities of glutathione peroxidase and catalase. CFTR silencing also resulted in elevated protein expression of pro-inflammatory tumor necrosis Factor-α, interleukin-6, cyclooxygenase-2, and the transcription factor nuclear factor-κB. Moreover, exaggerated OxS and inflammation processes occurred in CFTR(-/-) cells in response to the addition of Fe/Asc and LPS, respectively.

CONCLUSIONS

Intestinal Caco-2/15 cells with CFTR deletion, display innate oxidative and inflammatory features while being more sensitive to pro-oxidant and pro-inflammatory stimuli. These two pathophysiological processes could be implicated in CF-related intestinal disorders.

[Therapeutic advances in cystic fibrosis in 2014]

Twenty-five years after the cystic fibrosis (CF) gene identification, this discovery actually begins to benefit to patients. Increasing our knowledge on CFTR biology, as well as technical progress made in order to screen for new drugs have made therapeutic strategies move an important step forward. It is likely that in the forthcoming years, the panel of molecules available for CF patients will be larger, with new activators and potentiators. The disease by itself may consequently change in its natural history. CF is an example of the so-called personalized medicine, aiming to fit treatment according to patient's genetic background. Ongoing clinical trials may enlarge the actually limited eligible number of CF patients for new drugs such as ivacaftor. Beyond this exciting and promising new therapeutic approach, one may not push symptomatic treatments on the side. Improvements have been made for inhaled antibiotics administration, aiming to simplify patient's life; clinical trials using new molecules able to liquefy mucus or with anti-inflammatory properties are actually underway. One important next step in the care for CF will be to design and conduct early intervention trials in CF infants. Newborn screening program have been widely implanted around the word, and cohorts studies have shown that both functional and structural abnormalities occurred very early, making the therapeutic window of opportunity tight.

Cystic fibrosis-related oxidative stress and intestinal lipid disorders

SIGNIFICANCE

Cystic fibrosis (CF) is the most common lethal genetic disorder in the Caucasian people. It is due to the mutation of cystic fibrosis transmembrane conductance regulator (CFTR) gene located on the long arm of the chromosome 7, which encodes for CFTR protein. The latter, an adenosine triphosphate binding cassette, is a transmembrane chloride channel that is also involved in glutathione transport. As glutathione/glutathione disulfide constitutes the most important pool of cellular redox systems, CFTR defects could thus disrupt the intracellular redox balance. Resulting multisystemic diseases are essentially characterized by a chronic respiratory failure, a pancreatic insufficiency, an essential fatty acid deficiency (EFAD), and inadequate levels of antioxidant vitamins.

RECENT ADVANCES

The pathophysiology of CF is complex; however, several mechanisms are proposed, including oxidative stress (OxS) whose implication is recognized and has been clearly demonstrated in CF airways.

CRITICAL ISSUES

Little is known about OxS intrinsic triggers and its own involvement in intestinal lipid disorders. Despite the regular administration of pancreatic supplements, high-fat high-calorie diets, and antioxidant fat-soluble vitamins, there is a persistence of steatorrhea, EFAD, and harmful OxS. Intriguingly, several trials with elevated doses of antioxidant vitamins have not yielded significant improvements.

FUTURE DIRECTIONS

The main sources and self-maintenance of OxS in CF should be clarified to improve treatment of patients. Therefore, this review will discuss the potential sources and study the mechanisms of OxS in the intestine, known to develop various complications, and its involvement in intestinal lipid disorders in CF patients.

[Therapeutic update in cystic fibrosis]

We present the recent therapeutic advances in the cystic fibrosis care. It concerns improvements in symptomatic treatment with the development of dry powder inhaled antibiotics that improved quality of life, and innovative treatments namely the modulators of the cystic fibrosis transmembrane protein conductance regulator (CFTR), molecules which act specifically at the level of the defective mechanisms implied in the disease. The life expectancy of cystic fibrosis patients born after 2000, is estimated now to be about 50 years. This improvement of survival was obtained with the organization of the care within the specialized centers for cystic fibrosis (Centre de ressource et de compétences de la mucoviscidose) and remains still based on heavy symptomatic treatments. Dry powder inhaled antibiotics constitute a significant time saving for patients to whom all the care can achieve two hours daily. Since 2012, the modulators of CFTR, molecules allowing a pharmacological approach targeted according to the type of the mutations, allows a more specific approach of the disease. Ivacaftor (Kalydeco(®)) which potentialises the function of the CFTR protein expressed on the cellular surface is now available for patients with the G551D mutation. Lumacaftor is going to be tested in association with ivacaftor in patients with the F508del mutation, that is present in at least 75% of the patients. The ataluren which allows the production of a functional protein CFTR in patients with a no sense mutation is the third representing of this new therapeutic class. We presently have numerous symptomatic treatments for the cystic fibrosis care. The development of CFTR modulators, today available to a restricted number of patients treated with ivacaftor represents a very promising therapeutic avenue. It will represent probably the first step to a personalized treatment according to CFTR genotype.

[Mental retardation revealing mucopolysaccharidosis type I in a child treated for cystic fibrosis: a case report]

Mucopolysaccharidosis I (MPS I) is a lysosomal storage disease due to an α-L-iduronidase deficiency, which leads to an accumulation of glycosaminoglycans in the lysosomes of most cells, resulting in tissue and organ dysfunction. MPS I is inherited in an autosomal-recessive manner. This disorder has a chronic, progressive course and is characterized by mental retardation, dysmorphy, organomegaly, multisystem involvement, and multiple dysostosis. Early disease recognition is important for a prompt start of specific treatment, which improves many aspects of MPS I, and for the patient's overall management.

[Value of continuous glucose monitoring in screening for diabetes in cystic fibrosis]

AIMS

In the past few years, survival has increased for people with cystic fibrosis (CF). Diabetes is an important complication of CF caused by pancreatic insufficiency, which reduces insulin secretion. Because of increased longevity of patients with CF, the prevalence of CF-related diabetes (CFRD) has increased. CFRD is associated with increased mortality and morbidity. Several studies have reported a decline in nutritional and pulmonary status 2-4 years before the diagnosis of CFRD. The introduction of insulin treatment can produce clinical improvement in weight and lung function. The oral glucose tolerance test is currently the reference method in screening for CFRD, but the current definition of diabetes based on the 2-h post-load plasma glucose level may not be the most accurate method for early detection of glucose tolerance abnormalities in CF. The continuous glucose monitoring system (CGMS) has been described as a useful tool for early detection of hyperglycemia in the CF patient. We tested the CGMS in CF patients with unexplained alteration of their general status. The aim of this study was to assess the value of the CGMS in this population.

METHODS

An annual OGTT (following World Health Organization recommendations) was conducted as a screening test to identify CFRD in patients aged over 10 years or patients aged under 10 years with a poorer clinical status. The CGMS was performed in patients with unexplained worsened clinical status and without diabetes in OGTT.

RESULTS

Forty-two patients aged from 8.5 to 19 years were screened using OGTT for CFRD. According to ADA criteria, 23 patients (54.8%) displayed normal glucose tolerance, 14 (33.3%) impaired glucose tolerance, and 5 diabetes (11.9%). Out of 37 nondiabetic, the CGMS was used in 20 patients with unexplained altered general status. The CGMS revealed peaks of glucose values greater than 2 g/L in 16 patients, 9 patients with normal glucose tolerance, and 7 patients with impaired glucose tolerance. The mean CGMS glucose and time of glycemic monitoring above 1.4 g/L increased in patients with peaks greater than 2 g/L compared to patients without peaks (p=0.0016 and p=0.0069 respectively). After analysis of the CGMS, the prevalence of diabetes increased from 11.9 to 50%. Three patients aged less than 10 years with a normal OGTT profile presented glycemic peaks greater than 2 g/L during CGMS.

CONCLUSION

CGMS revealed more glucose metabolism abnormalities than OGTT in patients with unexplained altered general status.