Cystic Fibrosis Flashcards
Cystic Fibrosis Transmembrane Regulating (CFTR) protein
> Transmembrane (channel) protein involved in ion transport
Controls flow of water + Chloride ions between membranes
Encoded on Chromosome 7
*Change in the structure of this protein results in blockage of ion passage
What is Cystic fibrosis
> Inherited Autosomal Recessive Disease
Most common cause is a change to CFTR protein gene on chromosome 7 (over 1500 mutations)
Creating compromised ion transport (impaired Chloride ion transport will affect sodium levels in cells and thus water levels)
Affects several organs as ducts and airways become blocked by mucus (breeding ground for infection)
Also results in replacement of damaged cells with connective tissue = scarring (fibrosis element)
Pathology of Cystic Fibrosis
> Respiratory disease
- abnormally concentrated fluid in lungs (viscous secretions in airways)
- Dehydrated airways (mucus is even stickier than normal)
- Mucus is more difficult to clear and results in inflammation and scarring
- Also leaves a patient predisposed to infection
> High Sodium Sweat
- Chloride ions = not absorbed
- prevents sodium absorption
+ limited recognition of thirst = further dehydration
> Pancreatic Insufficiency
- Abnormal ion transport = dehydration of pancreatic secretions
- stagnation in pancreatic duct (may cause diabetes in later life)
> Biliary Disease
- Reduced water movement in lumen = concentrated bile + damaged lumen
> Infertility
- men: lack vas deferens (sperm can’t travel from testes to urethra)
- women: abnormally thick cervical mucus (impaired fertility)
> Cirrhosis of liver
> Gastrointestinal disease
- Intraluminal water deficiency = constipation
Diagnosis of Cystic Fibrosis
> Genetic testing (mouthwash or blood test)
- history of CF in family (usually if going to have kids)
> Heel prick test - all babies in UK
> Sweat test - higher concentration of chloride (as salt) in sweat
Symptoms of Cystic Fibrosis
- babies
- lungs
- digestive system
> Babies
- 10% of babies born with bowel obstruction (meconium ileus)
- meconium = thick black substance normally passed within first 2 days but in CF is too thick to pass and creates blockage in bowels
- Jaundice - build up of bilirubin in blood + body tissues (yellowing of skin/eyes/mucous membrane)
> Lungs
- persistent cough (+ coughing fits)
- inflammation in lungs (wheeze/SoB/difficulty breathing
- Recurring chest + lung infections
- Cross infection (easily spread + catch infection)
- Impaired diaphragm due to engorged liver
> Digestive system
- Large smelly stools (malabsorption of fats + proteins)
- Malnutrition/ poor weight gain/ stunted growth (pancreatic ducts = blocked = fewer digestive enzymes)
Symptoms of CF - other systems
> Diabetes
Sinusitis + Nasal Polyps (related to chronic inflammation)
Arthritis
Osteoporosis (malnutrition)
Infertility
Liver failure (bile duct = blocked by mucus)
Urinary Incontinence (due to chronic cough)
Delayed puberty (malnutrition)
MSK system
- Inspiratory muscle atrophy
- Weakness in anti-gravity muscles (gastrocnemius)
- kyphosis of spine = neck/back pain
Treatment for CF
> Medication
- Bronchodilators
- Hypertonic Saline Nebulisers
- Antibiotics
- Mucolytics
- Steroids - reduce inflammation
- Routine Vaccinations (Flu/pneumonia)
- Digestive enzymes (aid absorption of nutrients)
> Education
- Diet + Exercise
- Management
> Physiotherapy
- aid clearance of secretions (postural drainage/ percussion/ breathing techniques/ suction/mobilisation + exercise)
> Lung transplant (lungs will not have disease but rest of systems will)
> Psychological support
Prognosis for CF
> No cure or prevention
50% live past 40
Lung complications = usual cause of death
QoL depends on mutation/environment/developmental factors
Prevalence of CF
> 1 in 25 caucasians
2 carries have 25% chance of CF baby + 50% chance of carrier baby
~10,400 people in UK have CF (2-3 deaths per week)
