chromogranin B
A secretory protein found in neuroendocrine cells, used as a biomarker for neuroendocrine tumors.
Full Definition
Chromogranin B is a member of the granin family of proteins present in the secretory vesicles of neuroendocrine cells throughout the body. This acidic glycoprotein serves as both a structural component of dense-core vesicles and a precursor to bioactive peptides. In clinical practice, chromogranin B is utilized as a diagnostic and prognostic biomarker for various neuroendocrine tumors, complementing chromogranin A measurements. Elevated serum levels often correlate with tumor burden and can be monitored during treatment to assess therapeutic response. The protein is particularly useful in cases where chromogranin A levels may be falsely elevated due to proton pump inhibitor use.
Usage
Usage note: Distinguish clearly from chromogranin A in clinical contexts; both serve as neuroendocrine markers but may show different patterns.
In Context
- "Chromogranin B levels remained elevated despite octreotide therapy, suggesting disease progression." — Clinical case report
- "Immunohistochemical staining for chromogranin B confirmed the neuroendocrine nature of the pancreatic mass." — Pathology report