Anti-Calretinin CE/IVD antibodies for immunohistochemistry (IHC) in pulmonary pathology are widely used reagents integrated into clinically validated diagnostic workflows for detecting calretinin (CALB2), a calcium-binding protein associated with mesothelial differentiation. Their role in standardized panels is well supported for evaluating pleural malignancies and distinguishing malignant mesothelioma from pulmonary carcinomas.
Biological Significance of Calretinin in Pulmonary Pathology
Calretinin is a 29-kDa EF-hand calcium-binding protein involved in intracellular calcium signaling and cellular differentiation.
- Physiologically expressed in:
- Mesothelial cells lining the pleura.
- Neuronal and selected endocrine tissues.
- In thoracic pathology:
- Shows strong nuclear and cytoplasmic expression in mesothelial cells.
- Diffuse expression in malignant mesothelioma, especially epithelioid subtypes, while often reduced or absent in sarcomatoid variants.
- Functional implication:
- Marker of mesothelial differentiation rather than a tumor-specific antigen.
Diagnostic Utility of Calretinin in Pulmonary Pathology
Calretinin is a well-established positive mesothelial marker in IHC.
- Differential diagnosis:
- Mesotheliomas: typically strong, diffuse positivity.
- Lung adenocarcinomas: rarely positive (generally <10%, depending on study and clone).
- Diagnostic performance:
- Sensitivity for epithelioid mesothelioma: ~80–100% (clone- and study-dependent).
- Meta-analyses report high accuracy (sensitivity ~0.9, specificity ~0.95), varying by specimen type and methodology.
- Interpretation considerations:
- Dual nuclear and cytoplasmic staining increases specificity.
- Not entirely specific: occasional expression in non-mesothelial tumors (e.g., squamous, breast).
- Panel-based approach: Used with WT1, CK5/6, D2-40, and epithelial markers (e.g., MOC-31, claudin-4).
Key Features of Anti-Calretinin CE/IVD Antibodies
CE-marked anti-calretinin antibodies for in vitro diagnostic use are optimized for clinical IHC workflows.
- Analytical performance: High sensitivity for mesothelial cells; robust detection in FFPE tissues.
- Staining characteristics: Distinct nuclear and cytoplasmic immunoreactivity.
- Technical considerations: Compatible with automated platforms; performance depends on clone and protocol optimization.
