1st order laboratory parameters – obligatory laboratory tests.
- Microbiologic examination of sputum [standard diagnostics] – for antibiotic regimen selection and follow-up.
- Common pathogens: Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus.
- Immunoglobulins (group of proteins (protein) formed in plasma cells and specifically bind as antibodies with foreign substances (antigens) to render them harmless):
- IgE – for the purpose of testing for allergic bronchopulmonary aspergillosis (ABPA) [> 500 ng/ml].
- IgA – secreted on all mucous membranes of the respiratory tract, eyes, gastrointestinal tract, genitourinary tract, and via special glands around the nipple of mothers, where it protects against pathogens; found in blood serum and body secretions [normal value: 70-380 mg/dl (> 18 years)]
- IgM – is the first class of antibodies formed on initial contact with antigens and indicates the acute infectious phase of a disease; occurrence in blood serum [normal values: 40-230 mg/dl (men > 18 years); 40-280 mg/dl women > 18 years)]
- Determination of neutrophil elastase (from sputum obtained) [prognostic parameter!] – increased elastase activity correlates with a probability of hospitalization and mortality (mortality).
- Digression: neutrophil granulocyte elastase has proinflammatory (proinflammatory) effects, decreases cilia frequency, and promotes mucus secretion. In healthy individuals, elastase activity is inhibited by bronchial epithelial antiproteases and alpha-1-antitrypsin.
- Blood gas analysis (BGA) – for dyspnea (shortness of breath).
- Inflammation parameters – CRP (C-reactive protein) or ESR (blood sedimentation rate).
- Differential blood count
Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification.
- Alpha-1 antitrypsin – to exclude alpha-1 antitrypsin deficiency in bronchiectasis with unexplained cause.
- CFTR genetics – in young adults, family history of cystic fibrosis (CF), upper lobe bronchiectasis, recurrent rhinosinusitis (simultaneous inflammation of the nasal mucosa (“rhinitis”) and the mucosa of the paranasal sinuses (“sinusitis“)), exocrine pancreatic insufficiency (disease of the pancreas associated with insufficient production of digestive enzymes) or primary infertility.
