16 April 2026
: Case report 
Efgartigimod as Rescue Therapy for PD-1 Inhibitor–Associated Myasthenia Gravis, Myocarditis, and Myositis (MMM) Syndrome: A 2-Case Report and Literature Review
Challenging differential diagnosis, Unusual or unexpected effect of treatment, Unexpected drug reaction, Educational Purpose (only if useful for a systematic review or synthesis), Rare coexistence of disease or pathology
Zi-Han Liu ABCDEF 1,2, Li-Min Duan ABCDEF 2, Xiang-Zhi Fang ABCDEF 2, Wen Jiang BCDF 2, Sheng-Wen Sun ABCE 2, You Shang
AF 1,2*, Chao-Lin Huang A 1, Yin Yuan AG 1,2
DOI: 10.12659/AJCR.951872
Am J Case Rep 2026; 27:e951872
Table 1 Myasthenia-related autoantibody profile in the two PD-1 inhibitor–associated MMM syndrome cases.
| Autoantibody | Reference range | Case 1 | Case 2 |
|---|---|---|---|
| Anti-AChR | <0.5 nmol/L | 2.973 nmol/L | <0.001 nmol/L |
| Anti-MuSK | <0.05 nmol/L | 0.01 nmol/L | <0.001 nmol/L |
| Anti-titin | <1 | 0.09 | 2.287 |
| Anti-VGCC | ≤30 pmol/L | 2.51 pmol/L | 2.785pmol/L |
| Anti-LRP4 | Qualitative | (−) | (−) |
| MMM – myasthenia gravis, myocarditis, and myositis; AChR – acetylcholine receptor; MuSK – muscle-specific receptor tyrosine kinase; LRP4 – low-density lipoprotein receptor-related protein 4; VGCC – voltage-gated calcium channel. | |||