November 2022
Ampath | ampath.co.za
Updated Terminology
✅ ENA/CTD Screen and Profile
- The former CTD Profiles 1 and 2 have been consolidated into a single ENA/CTD profile using line immunoassay technology.
- The ENA/CTD screen includes the following antibodies (reported as positive/negative):
- RNP
- Sm
- SSA (Ro-60)
- SSB (La)
- Scl-70 (Topoisomerase I)
- Jo-1
- Centromere-B
- PM-Scl
- Mi-2
- Fibrillarin
- PCNA
- Ribosomal P-protein
- dsDNA
- RNA Polymerase III
- Ro-52
If the ENA/CTD screen is positive, the ENA/CTD profile should be requested to identify specific autoantibodies.
✅ ENA/CTD Profile – 16 Autoantibodies Reported Qualitatively:
- Sm/RNP
- Sm
- SSA (Ro-60)
- Ro-52
- SSB (La)
- Scl-70 (Topoisomerase I)
- PM-Scl
- Jo-1
- Centromere B
- PCNA
- Nucleosome
- Histone
- Ribosomal P-protein
- AMA-M2
- DFS-70
This profile is cost-effective and streptavidin-biotin-free, avoiding false positives from streptavidin antibodies.
Follow-Up Testing Suggestions
- If the ENA/CTD screen is positive but the profile is negative, consider a:
- Myositis line immunoassay, or
- Systemic sclerosis line immunoassay
- Based on clinical findings
- Individual antigens can also be requested if clinically appropriate.
✅ dsDNA Testing
- A dsDNA ELISA, complexed with nucleosome (to reduce non-specific binding), is available.
- Must be specifically requested for quantitative monitoring.
✅ Cytoplasmic Antibodies
- If observed on ANA screen, a cytoplasmic autoimmune profile is available on request.
Updated Autoimmune Profiles (Line Immunoassays)
🔹 Cytoplasmic Profile
- AMA-M2
- 3E (BPO)
- Ribosomal P
- Jo-1
- SRP
- PL-7
- PL-12
- EJ
- OJ
- Ro-52
🔹 Myositis Profile
- Mi-2α (alpha)
- Mi-2β (beta)
- TIF1γ
- MDA5
- NXP2
- SAE1
- Ku
- PM-Scl 100
- PM-Scl 75
- Jo-1
- SRP
- PL-7
- PL-12
- EJ
- OJ
- Ro-52
🔹 Systemic Sclerosis Profile
- Scl-70 (Topoisomerase I)
- Centromere A
- Centromere B
- RNA Pol III (RP11 and RP155)
- Fibrillarin
- NOR-90
- Th/To
- PM-Scl 100
- PM-Scl 75
- Ku
- PDGFR
- Ro-52
🔹 Autoimmune Liver Profile
- AMA-M2
- 3E (BPO)
- Sp100
- PML
- gp210
- LKM-1
- LC-1
- SLA/LP
- Ro-52
🔹 ENA Profile (Expanded)
- Sm/RNP
- Sm
- SSA (Ro-60)
- Ro-52
- SSB (La)
- Scl-70
- PM-Scl
- Jo-1
- Centromere B
- PCNA
- Nucleosome
- Histone
- Ribosomal P-protein
- AMA-M2
- DFS-70
🔹 Neuronal Autoimmune Profile
- IFA: Yo, Hu, Ri
- Line Immunoassay: Amphiphysin, CV2, PNMA2 (Ma-2/Ta), Ri, Yo, Hu, Recoverin, SOX1, Titin, Zic4, GAD65, Tr (DNER)
🔹 NMDA Autoimmune Encephalitis Profile
- NMDA
- AMPA 1
- AMPA 2
- GABA-B receptor
- CASPR2
- LGI-1
🔹 Ganglioside Antibody Profile
- GM1 IgM
- GM1 IgG
- GM2 IgM
- GM2 IgG
- GD1a IgM
- GD1a IgG
- GM3 IgM
- GM3 IgG
- GD1b IgM
- GD1b IgG
- GT1b IgM
- GT1b IgG
- GQ1b IgM
- GQ1b IgG
🔹 Other Organ-Specific Profiles
- Available as listed on Ampath’s updated autoimmune request form
Recommended Autoimmune Workup
If connective tissue disease (CTD) is suspected:
- Request ANA + ENA/CTD screen
- If ENA/CTD screen is positive → follow with ENA/CTD profile
Why include ENA/CTD screen even if ANA is negative?
- Some antibodies (e.g. Ro-52, SSA (Ro-60), ribosomal P-protein, myositis markers) may be missed by ANA immunofluorescence
- Combining ANA with ENA/CTD screen improves early detection and accurate diagnosis of autoimmune diseases
Conclusion
Ampath is committed to:
- Simplifying autoimmune diagnostics
- Expanding profile options
- Containing patient costs
- Offering international send-away testing for rare/new antibodies
- Providing customisable and electronic request forms
The combination of ANA and ENA/CTD screen increases diagnostic sensitivity for CTD and supports better patient care.
📌 Contact your local Ampath pathologist or marketer for guidance, forms, or additional testing support.
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