Diagnosis of cystic fibrosis

Diagnosing cystic fibrosis can be done in a variety of ways such as testing the sweat of the patient, performing a genetic test such as saliva test and screening the newborn child since the disease normally begins at birth.

Sweat testing is the most predominant technique used in diagnosing cystic fibrosis. It is done through the application of pilocarpine over the skin. Pilocarpine is a drug that induces sweating. Pilocarpine enters the skin when an electrode is dipped into it and an electric current passes through another electrode on the skin. The sweat that comes out is then collected onto a filter paper or into a capillary tube to be examined for excessive quantities of sodium and chloride as they exist naturally in large amounts in patients of cystic fibrosis. 

Screening of the newborn involves looking out for high concentrations of immunoreactive trypsinogen in the blood. Trypsinogen is an inactive chemical that is secreted by the pancreas. Its function is to aid in the break down and digestion of protein. The term immunoreactive refers to a substance that causes or affects an immune reaction.

An immunoreactive trypsinogen test known as IRT is done to check for an increase in the risk of cystic fibrosis and to help diagnose the inadequacy of digestive enzymes produced by the pancreas. The failure of the pancreas to produce enough chemicals and digestive enzymes is known as exocrine pancreatic insufficiency (EPI).  Trypsin is an enzyme obtained from trypsinogen which is produced by the pancreas. 

The quantity of trypsinogen could be augmented in patients with a mutated reproduction of the CFTR gene and in exceptional cases in persons with two regular reproductions of CFTR gene.

Testing one’s saliva is an ideal way of diagnosing one of many health disorders. It is recognized as an efficient means of diagnoses as samples of saliva can be simply collected and stored as compared to urine or blood. It is a means by which the disease could be detected early. Samples could also be taken anywhere thereby speeding up the process of test.

In order to detect symptoms of cystic fibrosis at birth, a woman must undergo saliva examination once she is pregnant. Additionally, her partner should also be examined for possible abnormal functioning of his gene.

Abnormalities in gene functioning is caused by alterations in CFTR protein, a protein that is found in the membranes of cells within the passageways of the lungs, liver, pancreas, intestines, reproductive tract and skin. CFTR also aids in regulating other transport pathways of the body. Changes in the functioning of this protein could result in cystic fibrosis and congenital bilateral absence of the vas deferens (CBAVD).

In order that a child contracts cystic fibrosis from birth, the genes of both parents must exhibit mutations or changes in the CFTR protein. A child with a single mutated gene would usually not exhibit signs of cystic fibrosis.

Diagnostic tools like X-rays and CAT scans inspect the lungs for damage or infection.