===== MDA5 and ASYS =====

<code>BLUF: lineblot is highly prone to FP and FN results. IP is best overall, but ELISA is a faster, acceptable non-IP alternative.</code>

Modality ranked by highest to lower //specificity//:

  - IP > ELISA >> multiplex bead assays >> lineblot


Modality ranked by highest to lower //sensitivity//:

  - ELISA >= IP >> multiplex bead assays >> lineblot

==== Reliable test options ====

<code>Use OMRF or Labcorp ELISA options. Avoid Quest</code>

^ lab      ^ test_name                  ^ link                                                               ^ antibodies                                                                                                                                                                                                                                                                                         ^ test\_modality  ^ notable\_feature                                           ^
|OMRF| Comprehensive Myositis Autoantibody Profile|https://omrf.org/patients/clinical-testing-lab/ | Jo-1, PL7, PL12, EJ, OJ, SRP, Mi-2, PMScl, Ku, Ro60, U1RNP, U2RNP, p155/140 (TIF1g), MJ (NXP2), caDM140 (MDA5) | IP|gold standard but no quantification of levels like in ELISA|
| Labcorp  | Anti-Synthetase Profile (RDL)| https://www.labcorp.com/tests/520193/anti-synthetase-profile-rdl   | Anti-EJ Ab; Anti-Jo-1 Ab; Anti-OJ Ab; Anti-PL-7 Ab, Anti-PL-12 Ab                                                                                                                                                                                                                                  | ELISA and RIPA  | RIPA has superior sensitivity for detecting anti-OJ        |
| Labcorp  | MyoMarker® 3 Plus Profile  | https://www.labcorp.com/tests/520085/myomarker-3-plus-profile-rdl  | Anti-PM/Sci-100 Ab; Anti-MDA5 Ab (CADM-140); Anti-NXP-2 Ab; Anti-TIF-1gamma Ab; Anti-SAE1 Ab, IgG; Anti-SRP Ab; Anti-U3 RNP (Fibrillarin Ab); Anti-U2 RNP Ab; Anti-Mi-2 Ab; Anti-PL-7 Ab; Anti-PL-12 Ab; Anti-EJ Ab; Anti-OJ Ab; Anti-Ku Ab; Anti-Jo-1 Ab; Anti-U1 RNP Ab; Anti-SS-A 52kD Ab, IgG  | ELISA and RIPA  | large MSA and MAA screen; includes RO52 ELISA measurement  |
|Quest|Myositis Specific 11 Antibodies Panel | https://testdirectory.questdiagnostics.com/test/test-detail/94777/myositis-specific-11-antibodies-panel?cc=MASTER|Jo-1 Ab, Pl-7 Ab, Pl-12 Ab, EJ Ab, OJ Ab, SRP Ab, Mi-2 Alpha Ab, Mi-2 Beta Ab, MDA5 Ab, TIF1 Gamma Ab, NXP-2 Ab| **line blot** | test is line blot only; regard results not orthogonally confirmed with skepticism |
|Quest|Extended Myositis Specific Antibody (MSA) Panel | https://testdirectory.questdiagnostics.com/test/test-detail/10257/extended-myositis-specific-antibody-msa-panel?p=r&cc=MASTER|Myositis Specific 11 Antibodies Panel (JO1, PL7, PL12, EJ, OJ, SRP, MI-2a/b, MD5, TIF1G, NXP2) HMGCR, cN-1A| **ASYS ab are line blot** | test is line blot only for ASYS-Ab; regard results not rthogonally confirmed with skepticism |