A genetic disorder, characterized by a tendency to develop chronic lung infections and an inability to absorb fats and other nutrients from food. The main feature of cystic fibrosis (CF) is secretion of sticky mucus, which is unable to flow freely, in the nose, throat, airways, and intestines.
The course and severity of the disease vary. Typically, a child passes unformed, pale, oily, foul-smelling faeces and may fail to thrive. Often, growth is stunted and the child has recurrent respiratory infections. Without prompt treatment, pneumonia, bronchitis, and bronchiectasis may develop, causing lung damage. Most male sufferers and some females are infertile. CF causes excessive loss of salt in sweat, and heatstroke and collapse may occur in hot weather.
This is the most common serious genetic disease in Caucasian children, with an incidence of about one per 2,500 births, and more than 6,000 patients in the UK (30,000 in the USA). It is an autosomal recessive disorder of the mucus-secreting glands of the lungs, the pancreas, the mouth, and the gastrointestinal tract, as well as the sweat glands of the skin. The defective gene is sited on chromosome 7 which encodes for a protein, cystic ?brosis transmembrane conductance regulator (CFTR). Individuals who inherit the gene only on one set of chromosomes can, however, carry the defect into successive generations. Where parents have a child with cystic ?brosis, they have a one-infour chance of subsequent children having the disease. They should seek GENETIC COUNSELLING.
The disorder is characterised by failure to gain weight in spite of a good appetite, by repeated attacks of bronchitis (with BRONCHIECTASIS developing at a young age), and by the passage of loose, foul-smelling and slimy stools (faeces). AMNIOCENTESIS, which yields amniotic ?uid along with cells shed from the fetus’s skin, can be used to diagnose cystic ?brosis prenatally. The levels of various enzymes can be measured in the ?uid and are abnormal when the fetus is affected by cystic ?brosis. Neonatal screening is possible using a test on blood spots – immunoreactive trypsin (IRT).
In children with symptoms or a positive family history, the disease can be tested for by measuring sweat chloride and sodium. This detects the abnormal amount of salt that is excreted via the sweat glands when cystic ?brosis is present. Con?rmation is by genetic testing.
Treatment This consists basically of regular physiotherapy and postural drainage, antibiotics and the taking of pancreatic enzyme tablets and vitamins. Some children need STEROID treatment and all require nutritional support. The earlier treatment is started, the better the results. Whereas two decades ago, only 12 per cent of affected children survived beyond adolescence, today 75 per cent survive into adult life, and an increasing number are surviving into their 40s. Patients with end-stage disease can be treated by heart-lung transplantation (with their own heart going to another recipient). Research is underway on the possible use of GENE THERAPY to control the disorder. Parents of children with cystic ?brosis, seeking help and advice, can obtain this from the Cystic Fibrosis Trust.
(fibrocystic disease of the pancreas, mucoviscidosis) a hereditary disease affecting cells of the exocrine glands (including mucus-secreting glands, sweat glands, and others). The faulty gene responsible for the most common form of the disease has been identified as lying on chromosome no. 7 and is recessive, i.e. both parents of the patient can be *carriers without being affected by the disease. Affected individuals have abnormalities in a protein, cystic fibrosis transmembrane conductance regulator (CFTR), that enables the transport of chloride ions across cell membranes: this results in the production of thick mucus, which obstructs the intestinal glands (causing meconium *ileus in newborn babies), pancreas (causing deficiency of pancreatic enzymes resulting in *malabsorption and *failure to thrive), and bronchi (causing *bronchiectasis). Respiratory infections, which may be severe, are a common complication. Common agents include *Haemophilus, *Pseudomonas, *Staphylococcus, and Burkholderia cepacia. The sweat contains excessive amounts of sodium and chloride, which is an aid to diagnosis.
Treatment consists of minimizing the effects of the disease by administration of pancreatic enzymes and physiotherapy for the lungs and by preventing and combating secondary infection. Sputum viscosity can be reduced by nebulized recombinant human *DNAse. *Genetic counselling is essential, as each subsequent child of carrier parents has a one in four chance of being affected (see also mouthwash test; preimplantation genetic diagnosis). Some patients are benefiting from revolutionary new treatments, including transplantation of heart and lungs and treatment aimed at altering the genetic content of the faulty cells (see gene therapy).
The formation of ?brous or scar tissue, which is usually due to infection, injury or surgical operation.... fibrosis
The tube that runs from the gall-bladder (see LIVER) and joins up with the hepatic duct (formed from the bile ducts) to form the common BILE DUCT. The BILE produced by the liver cells is drained through this system and enters the small intestine to help in the digestion of food.... cystic duct
A condition which may develop in both LUNGS (interstitial pulmonary ?brosis) or part of one lung. Scarring and thickening of lung tissues occur as a consequence of previous lung in?ammation, which may have been caused by PNEUMONIA or TUBERCULOSIS. Symptoms include cough and breathlessness and diagnosis is con?rmed with a chest X-ray. The patient’s underlying condition should be treated, but the damage already done to lung tissue is usually irreversible. (See also ALVEOLITIS.)... pulmonary fibrosis
A lymphangioma that occurs around the head and neck, the armpits, or the groin and contains clear fluid. Cystic hygromas are usually present from birth and disappear naturally from the age of about 2.... hygroma, cystic
Scarring of lung tissue mainly involving the alveoli. There are a number of causes, including occupational exposure to dusts and fibrosing alveolitis, which is an autoimmune disorder.... interstitial pulmonary fibrosis
adj. 1. of, relating to, or characterized by cysts. 2. of or relating to the gall bladder or urinary bladder.... cystic
a collection of fluid behind the neck of a fetus, occasionally extending laterally to involve the sides of the neck (see hydrops fetalis). In its mildest form it is evidenced by an increased nuchal translucency (see nuchal translucency scanning). Cystic hygroma may be a diagnostic feature of chromosomal abnormality (e.g. Down’s syndrome, Turner’s syndrome).... cystic hygroma
(IPF) a serious interstitial lung disease, formerly called cryptogenic fibrosing alveolitis (see alveolitis). It is characterized by progressive fibrous scarring of the lung and increased numbers of inflammatory cells in the alveoli and surrounding tissues. The disease is usually diagnosed on clinical grounds on a basis of worsening breathlessness, inspiratory crackles at the lung bases on auscultation, clubbing of the fingers or toes, bilateral radiographic shadowing predominantly in the lower zones of the chest X-ray, subpleural *honeycomb change on CT scanning of the chest, and restrictive lung function on spirometry. It is also called usual interstitial pneumonia (UIP; see interstitial pneumonia), a term used by lung pathologists for the most common cellular pattern seen on biopsy. Treatment includes *pirfenidone, corticosteroids, and immunosuppressants.... idiopathic pulmonary fibrosis
(NSF, nephrogenic fibrosing dermopathy) a rare condition, first reported in 1997, that occurs exclusively in patients with chronic kidney disease (CKD), who develop large areas of hardened skin with fibrotic nodules and plaques. Flexion contractures with an accompanying limitation of range of motion can also occur. Exposure to gadolinium, used as a contrast agent in magnetic resonance imaging, has been identified as a causative factor, but many patients with severe CKD have been exposed to gadolinium without consequence. Linear gadolinium preparations (Omniscan, OptiMARK) appear to carry the highest risk of NSF. There is no cure for the condition.... nephrogenic systemic fibrosis
(RPF) a condition in which a dense plaque of fibrous tissue develops behind the peritoneum adjacent to the abdominal aorta. It may be secondary to malignancy, medication (methysergide, beta blockers), aortic aneurysm, or certain infections. The ureters become encased and hence obstructed, causing acute *anuria and renal failure. The obstruction can be relieved by *nephrostomy or the insertion of double J *stents. In the acute phase steroid administration may help, but in established RPF *ureterolysis is required.... retroperitoneal fibrosis
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