Test BackgroundCYFRA 21-1, a cytokeratin 19 (CK19) fragment, is an acid-type cytoplasmic protein with a molecular weight of 40 kDa that belongs to the intermediate filament group of proteins. Cytokeratins are sub-grouped into acidic type I (40-56.5 kDa) and basic type II (53-67 kDa). Cytokeratins 8, 18 and 19 are the most abundant types present in epithelial cells. Due to their release during cell proliferation or apoptosis, cytokeratins provide useful markers for epithelial malignancies.
Serum levels of CYFRA 21-1 are frequently elevated in lung cancer, particularly in non-small cell lung cancer patients (NSCLC). CYFRA 21-1 levels are particularly high in patients with squamous cell carcinoma. However, elevated levels of cytokeratin 19 fragments are also seen in other cancers, eg. bladder cancer. Elevated levels of CYFRA 21-1 may also be found in subjects with non-malignant disease including: acute pneumonia, tuberculosis, liver diseases and renal failure.
Clinical Indications Lung cancer
Sample Required Serum (red top) preferred, SST (gold top) acceptable
Sample Volume 0.5 mL
Turnaround Time 4 weeks
NotesBrahms Kryptor assay