Cystic fibrosis is an autosomal recessive disorder that affects the function of the exocrine glands in multiple organ systems, mainly resulting in chronic respiratory infections and insufficient pancreatic enzymes. Cystic fibrosis is caused by mutations of two gene pairs, one from mom and one from dad, on chromosome 7. However, if the person inherits mutations on just one gene they don’t actually have the disease but they are a carrier of Cystic fibrosis.
Chromosome 7 produces a protein called CF transmemebrane regulator. CF transmembrane regulator is responsible for regulating the channels of sodium and chloride, but when there are mutations on the gene the channels become blocked. When the channels become blocked, the cells that line the pathways to the organs such as the lungs and the pancreas produces thick, sticky mucus that plugs the glands and causes them to weaken. The mucus takes on this characteristic because it is lacking in chloride secretion and is excessive in sodium absorption.
CF is known mainly for its affects on the respiratory system. CF starts out by affecting the small airways, then moves to the large airways and eventually it destroys lung tissue. Because the mucus is thick and sticky the cilia is unable to move it. This causes the bronchials to become blocked which then causes an airway infection which is very difficult to treat.
The pancreas is also affected. It becomes insufficient because the thick, sticky mucus blocks the pancreatic exocrine ducts which lead to the formation of fibrotic cysts. When this happens it is likely that there will be a complete loss of pancreatic function. Because of this, the pancreas is unable to get the enzymes amylase and lipase to the intestines. These enzymes are needed for the digestion of fats, proteins, and for the absorption of the fat-soluble vitamins D, A, K, E.
CF related diabetes mellitus often occurs as a result of the scaring of the pancreas due to the fibrotic cysts that form. This type of diabetes is unique because it has characteristics of both Type 1 and Type 2. When a person has CF, the pancreas is still able to release some insulin but it is never enough to manage the carbohydrate intake. Therefore, insulin is needed to manage CFRD.
CF is usually diagnosed in infants. A few children with CF begin having symptoms at birth. It is noticed at birth because the child is unable to pass the meconium because it is thicker and sticker than that of a baby without CF. This causes the meconium to completely block the intestines. Also, because the baby’s enzymes are not absorbing the fat in its intestines his or her soiled diapers will appear fatty which may alarm the parents into thinking something is wrong.
Parents may also notice that when they kiss their baby they may taste “salty”. This is because when a child has CF, sodium and chloride can’t be absorbed as the sweat moves through the ducts causing about four times the amount of sodium and chloride in the sweat.
Meds commonly prescribed for Cystic fibrosis;
Pancrelipase
Multivitamin and Vitamins D,A,K,E
Bronchodialators
Dornase alfa
Ivacafton
Antibiotics:
-Tobramycin, Aztreonam, Gentamicin, Piperacillin, Cephalexin, Ceftazidime, Ciproflaxacin, Trimethoprim and Sulfamthoxazole, and Chloramphenicol.
Common lab tests ordered;
The main test to diagnose CF is called the sweat chloride test. If the results from this test are unclear, they physician may order genetic testing to be done.
The patient will also undergo a pulmonary function test, will likely have many chest x-rays due to the amount of respiratory infections they will get.
