Common tests for cystic fibrosis

Common tests for cystic fibrosis

Besides the tests to diagnose Cystic Fibrosis (CF), other tests can be done to see how the lungs and pancreas are functioning. Together, these tests can detect early signs of problems developing. And many of them are repeated every few months to monitor the patients health.

  • A pulmonary function test is a breathing test that tells how well the lungs are working. A person takes a deep breath and then blows into a machine that measures how deep and fully that person can breathe. The machine produces a report and often a line drawing that shows that person's breathing pattern.
  • The mucus someone coughs up or spits out can be checked for bacteria that cause lung infections. These tests, called sputum cultures, can also identify the antibiotics that would be best to fight the infection. 
  • Blood tests can check for infections, liver disease, diabetes, nutrition status, vitamin levels, and the side effects of medicines and much more.
  • Stool tests can be used to look for small amount of blood and to monitor the amount of malabsorption present. They can tell if someone with CF has enough pancreatic enzyme replacement therapy (PERT) balanced for their needs. 

TABLE: Common Tests in Cystic Fibrosis

Common TestsMeasuresLooks For
Complete Blood Count (CBC)White Blood CellsRed Blood Cells Platelets InfectionAnemiaClotting Problems
Basic Metabolic Profile (BMP)Sodium, potassiumChloride, carbon dioxideBUN, CreatnineHydration, low or high salts Acid (pH) balance
Hydration, Kidney function
Liver Function PanelLiver enzymesBilirubinAlbumin, proteinsLiver functionJaundiceProteins
CalciumCalciumCalcium in blood stream(does not measure what's in the bones)
Comprehensive panelBMP, Liver panel, Calcium Combination of these tests
Pre-albuminProteinProtein formation
Vitamins A or CaroteneDEB12 and folateFat absorption Bone density Fat absorption, anemian B vitamins
Protime (PT) and PTTClotting factorsVitamin K & liver Function
Minerals  PhosphorusMagnesiumZincBone, ricketsOften low if calcium isCan get low with diarrhea

TestMeasuresLooks for
ElastaseEnzyme that breaks down proteinPancreatic enzyme in the body
FatFat that's not absorbedFat absorption
pHAcid in bowel movementSugar absorption
Reducing substanceSugars in bowel movementSugar absorption
BloodBlood that can't be seenBlood from GI tract