[Pubmed] Diagnostic Challenges of LRP4 Antibody Testing in Myasthenia Gravis: A Case Series of Four LRP4 Positive Cases

[RSS-Bot]

Case Rep Neurol Med. 2026 Apr 30;2026:3092521. doi: 10.1155/crnm/3092521. eCollection 2026.

ABSTRACT

Myasthenia gravis is an autoimmune disorder characterized by muscle weakness due to impaired neuromuscular transmission. While antibodies against the acetylcholine receptor and muscle-specific kinase are commonly used for diagnosis, a subset of patients remains seronegative, necessitating alternative biomarkers. Low-density lipoprotein receptor-related Protein 4 antibodies have emerged as a potential diagnostic marker in seronegative myasthenia gravis cases. However, misleading positive results have obscured diagnosis and management. This study explores the clinical relevance of low-density lipoprotein receptor-related Protein 4 antibodies in myasthenia gravis through four patient case studies. Patients presenting with concern for myasthenia gravis underwent a comprehensive diagnostic evaluation, including antibody testing for acetylcholine receptor, muscle-specific kinase, and low-density lipoprotein receptor-related Protein 4. Volitional single-fiber electromyography was also performed. All tests were employed per standardized laboratory protocols. All four patients were initially evaluated for suspected myasthenia gravis; however, despite positive low-density lipoprotein receptor-related Protein 4 antibody results, comprehensive clinical and electrophysiological evaluation ultimately excluded the diagnosis of myasthenia gravis. These cases underscore the limitations of low-density lipoprotein receptor-related Protein 4 antibody testing.

PMID:42078791 | PMC:PMC13129935 | DOI:10.1155/crnm/3092521


Source: https://pubmed.ncbi.nlm.nih.gov/4207879 ... t6+133c1fe