1. Overview of IGHV
- Gene Name: IGHV (Immunoglobulin Heavy Chain Variable region)
- Function: Encodes the variable region of the immunoglobulin heavy chain in B cells
- Role in Immunity:
- Responsible for antigen recognition
- Contributes to B-cell receptor (BCR) diversity through V(D)J recombination
2. Clinical Relevance in B-Cell Malignancies
Definition of IGHV mutation status:
- Mutated IGHV: ≥2% deviation from germline sequence
- Indicates somatically hypermutated B cells
- Unmutated IGHV: <2% deviation from germline
- Indicates naive, unmutated B cells
Prognostic Implications in CLL:
| IGHV Status | Prognosis | Notes |
|---|---|---|
| Mutated | Favorable | Slower disease progression, better response to chemoimmunotherapy |
| Unmutated | Poor | Aggressive disease, shorter time to treatment, often requires targeted therapy (BTK inhibitors, BCL2 inhibitors) |
3. Mechanism / Biology
- Mutated IGHV: B cells have undergone somatic hypermutation in germinal centers → more mature phenotype → less proliferative in CLL
- Unmutated IGHV: Reflects naive B cells → more aggressive CLL biology
4. Clinical Implications
- Testing:
- Treatment Considerations:
- Unmutated IGHV patients respond better to targeted therapies (ibrutinib, acalabrutinib, venetoclax) than to chemoimmunotherapy
- Mutated IGHV patients may have durable response to chemoimmunotherapy (FCR regimen)
5. Other Notes
- IGHV in other B-cell malignancies:
- Can influence biology in follicular lymphoma, mantle cell lymphoma, but most studied in CLL
- Associated markers: Often considered with TP53 mutation/deletion to refine risk stratification
Key Takeaways
- IGHV mutation status is one of the strongest prognostic biomarkers in CLL.
- Mutated IGHV = better prognosis, unmutated = more aggressive disease.
- Guides treatment selection: chemoimmunotherapy vs targeted therapy.
Synonyms
IGHV