Cystic Fibrosis

Cystic Fibrosis (CF) is a chronic, genetic disease that affects the secretory glands, which are responsible for the production of fluids like mucus and sweat. Due to abnormal function of these glands, patients excessively produce a thick and sticky mucus that affects the respiratory, digestive and reproductive systems. It is particularly problematic in the lungs since the mucus accumulates and block the airways, leading to breathing difficulties.[1]

Cystic fibrosis is a common genetic disease within the white population in the United States. The disease occurs in 1 in 2,500 to 3,500 white newborns. Cystic fibrosis is less common in other ethnic groups, affecting about 1 in 17,000 African Americans and 1 in 31,000 Asian Americans. [2]
Most people with cystic fibrosis also have digestive problems. Some affected babies have meconium ileus, a blockage of the intestine that occurs shortly after birth. Other digestive problems result from a buildup of thick, sticky mucus in the pancreas. In people with cystic fibrosis, mucus blocks the ducts of the pancreas, reducing the production of insulin and preventing digestive enzymes from reaching the intestines to aid digestion. Problems with digestion can lead to diarrhea, malnutrition, poor growth, and weight loss. In adolescence or adulthood, a shortage of insulin can cause a form of diabetes known as cystic fibrosis-related diabetes mellitus (CFRDM). [2]



Genetic Changes :

Mutations in the CFTR gene cause cystic fibrosis. The CFTR gene provides instructions for making a channel that transports negatively charged particles called chloride ions into and out of cells. Chloride is a component of sodium chloride, a common salt found in sweat. Chloride also has important functions in cells; for example, the flow of chloride ions helps control the movement of water in tissues, which is necessary for the production of thin, freely flowing mucus.

Mutations in the CFTR gene disrupt the function of the chloride channels, preventing them from regulating the flow of chloride ions and water across cell membranes. As a result, cells that line the passageways of the lungs, pancreas, and other organs produce mucus that is unusually thick and sticky. This mucus clogs the airways and various ducts, causing the characteristic signs and symptoms of cystic fibrosis.

Other genetic and environmental factors likely influence the severity of the condition. For example, mutations in genes other than CFTR might help explain why some people with cystic fibrosis are more severely affected than others. Most of these genetic changes have not been identified, however. [2]

Cystic Fibrosis Statistics Worldwide :

Cystic fibrosis can be developed by people from both genders, as well as all races and ethnic groups. However, the incidence of CF varies across the globe. Cystic fibrosis is particularly common among Caucasians of Northern European descent and among Latinos and American Indians, especially the Pueblo and Zuni. The incidence of cystic fibrosis in the European Union one in 2000-3000 newborns, but there are also discrepancies among the different countries. On the contrary, the disease is severely underdiagnosed in Asia, and research on the topic suggests that the prevalence of CF is rare. [1]

The increase in CF patients’ life expectancy is a worldwide tendency, with a steadily growth in the number of adults who suffer from the disease. However, this also carry negative implications. Adult CF patients tend to experience additional health challenges including CF-related diabetes and osteoporosis. In addition, over 95% of men with CF are sterile. In addition to the increase in life expectancy, research also demonstrates that there has been a decrease in the incidence of the disease worldwide. [1]
According to the Cystic Fibrosis Foundation Patient Registry, in the United

States :
⦁ More than 30,000 people are living with cystic fibrosis (more than 70,000 worldwide).
⦁ Approximately 1,000 new cases of CF are diagnosed each year.
⦁ More than 75 percent of people with CF are diagnosed by age 2.
⦁ More than half of the CF population is age 18 or older. [3]
In Europe, the rate of cystic fibrosis is between 1:2000 and 1:3000 births. In southern Africa, the carrier frequency is 1 in 42, with a calculated incidence of 1 in 7056 births. The incidence in Latin America ranges from 1:3900 to 1:8500. Estimates for the Middle East are between 1:2560 and 1:15,876. [4]
Cystic fibrosis is rare among Asians. In India, the prevalence is estimated at around 1:40 000 to 1:100 000 births. In Japan, the estimated incidence is 1:100 000 to 1:350 000. [4]

Estimated Burden of Cystic fibrosis in India :

Total estimated live births in India during year 2012 were 27,271,000. The number of children born every year with CF may be about 10908 presuming incidence to be about 1 in 2500 live birth; 2727 with a presumed incidence of 1 in 10000; and 681 with a presumed incidence of 1 in 40000. Most of these children may be dying due to severe pneumonia or malnutrition as the diagnosis may not be made due to ignorance or non-availability of diagnostic tests.

The children with CF in India are diagnosed late, but the clinical features are similar to the patients from rest of the world. Indian patients differ from their counterparts from developed world in being frequently malnourished, having clinical evidence of fat soluble vitamin deficiencies and more chances of being colonized with Pseudomonas. Diagnostic facilities in India are scarce. Mutation profile is different with a lower prevalence of ΔF508. Management of CF in India is difficult due to inadequate trained manpower, lack of financial support, limited availability and high cost of pharmacologic agents. The determinants of early death in Indian children with CF include: severe malnutrition, colonization with Pseudomonas at the time of diagnosis, more than four episodes of lower respiratory infection per year and age of onset of symptoms before 2 months of age. [5]

Clinical Presentations in Indian Cystic fibrosis Cases :

The Indian CF patients mainly present with respiratory and gastrointestinal problems associated with malnutrition. Among these varied clinical symptoms, pulmonary involvement has been observed to be the most predominant and severe CF manifestation.

Although majority of CF cases present during infancy and childhood, a number of cases have been diagnosed in the adulthood. The cases presenting pancreatic abnormalities especially were observed, to possess a higher age group, indicating that the damage of pancreas inutero occurs progressively; and the patients can present with symptomatic pancreatic abnormalities as the initial manifestations of CF in adulthood. [6]

Diagnosis :

The diagnosis of cystic fibrosis requires a combination of clinical features suggestive of the disease with biochemical or genetic markers of CFTR dysfunction. (Table 1)

In a child with a high pretest probability of CF, the diagnosis is confirmed by sweat chloride estimation by pilocarpine iontophoresis method. A sweat chloride concentration of > 60 mmol/L is almost always diagnostic of CF, as a falsely elevated sweat chloride in the absence of CF is rare, although reported in a number of unusual clinical conditions; they can usually be readily distinguished from CF. Non-classic or atypical CF (1-2% of CF population), defines patients with a CF phenotype in at least one organ system and a normal or borderline sweat chloride level. In practice, the most common cause of incorrect sweat chloride results is laboratory error; therefore, it is recommended to be done only at CFF accredited care centers. But in countries like India where such facilities are not available, it should be carried out in experienced laboratories and repeated 2-3 times. [5]

Symptoms :

The type and severity of CF symptoms can differ widely from person to person. The most common symptoms are:
⦁ Very salty-tasting skin
⦁ Persistent coughing, at times with phlegm
⦁ Frequent lung infections, such as pneumonia or bronchitis
⦁ Wheezing or shortness of breath
⦁ Poor growth or poor weight gain in spite of a good appetite
⦁ Frequent greasy, bulky stools or difficulty in bowel movements
⦁ Small, fleshy growths in the nose, called nasal polyps
⦁ Chronic sinus infections
⦁ Clubbing or enlargement of the fingertips and toes
⦁ Rectal prolapse (when the rectum sticks out through the anus)
Male infertility[5]

Cystic Fibrosis Medications :

Cystic fibrosis is a life-threatening, genetic disease that affects patients’ ability to breathe and is marked by persistent lung infections. While it currently has no cure, a number of treatments, therapeutics, and supplements exist to help cystic fibrosis patients maintain their health and well-being. These include medications approved for the disease, but treatment plans are unique and tailored to each patient’s specific health characteristics and needs. Cystic fibrosis medications range from CFTR modulators and enzyme supplements, to mucolytics, antibiotics, and vitamins. [7]

Enzymes to Treat Cystic Fibrosis :

According to the Cystic Fibrosis Foundation (CFF), 87 percent of people with cystic fibrosis need to take enzymes. These supplements come in the form of oral capsules that work in the intestines to help patients absorb nutrients from their food. Each capsule has small beads with digestive enzymes, and is covered with a special enteric coating to allow the beads to dissolve in the small intestine. It is important that patients take the right amount of enzymes, just before a meal, and should check with the dietitian on their CF care team for the exact amount of enzymes to take. Enzymes help patients digest carbohydrates, proteins and fats; gain and maintain a healthy weight; and absorb essential nutrients, such as vitamins and minerals. Enzymes for patients with cystic fibrosis include:
Pancrelipase (Cotazym, Cotazym-S, Creon, Dygase, Ku-Zyme, Ku-Zyme HP, Kutrase, Lapase, Lipram, Lipram UL, Palcaps 10, Pancrease MT, Pancreaze, Pancrecarb MS, Pangestyme CN 10, Pangestyme EC, Panocaps, Panocaps MT 16, Panokase, Pertzye, Ultrase, Viokace, Viokase, Zenpep)
⦁ Pancreatin (Hi-Vegi-Lip, Pan-2400, Pancreatin 4X) [7]

Mucolytics for Patients with Cystic Fibrosis :

Mucolytics are in a category of cystic fibrosis medications designed to help thin mucus in the lungs so patients can cough and expel mucus more easily. These inhaled medications “cut up” the DNA strands outside the cell that are responsible for making CF mucus thick and sticky. The DNA strands are formed in the white blood cells and are able to fight lung infections. By moving the mucus out of the lungs, the damage caused by chronic lung infections is delayed or reduced. The class of mucolytic medications include:
Dornase alfa (Pulmozyme)
⦁ Hypertonic saline[7]

Antibiotics to Help Cystic Fibrosis Patients :

Lung infections are particularly common in cystic fibrosis, and antibiotics are used to fight or control infection-causing bacteria. There are oral antibiotics (liquids, tablets or capsules to be swallowed), intravenous (IV) antibiotics (liquid medicine administered directly into the blood through a catheter), and inhaled antibiotics (an aerosol or mist inhaled directly to the airways). The choice of antibiotic drug, dosage, and duration of treatment depend on the patient and the infection, but the options include:

⦁ Tobramycin inhalation solution (TOBI, Bethkis)
⦁ Aztreonam for inhalation solution (Cayston, Azactam)
⦁ Tobramycin inhalation powder (TOBI Podhaler)
⦁ Azithromycin (Zithromax, Zmax)
⦁ Amikin (Amikacin)
⦁ Gentamicin (Garamycin[7]

Vitamins to Ease Cystic Fibrosis Symptoms :

Vitamins can help the bodies of patients with cystic fibrosis to grow, function better, and fight infections. While vitamin A is used to improve vision, bone and tooth formation, cell function, and immunity, vitamin D helps to build and maintain strong bones and teeth. Vitamin E is particularly important as it is an antioxidant that protects compounds in the body from combining with oxygen, keeping red blood cells healthy and helping to fight infections. In addition, vitamin K helps the blood to clot and helps maintain the health of the bones. Some vitamins of note include:
⦁ Alpha E
⦁ Amino-Opti-E
⦁ Aqua Gem-EAqua-E
⦁ Aquasol E
⦁ Aquavite-E
⦁ Centrum Singles-Vitamin E
⦁ E Pherol
⦁ E-400 Clear
⦁ E-600
⦁ E-Gems
⦁ Nutr-E-Sol
⦁ Vita-Plus E Natural [7]

References :

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