Myasthenia gravis - acetylcholine receptors autoantibodies positive (AchR+ MG) subtypes and their clinical manifestations

Abstract

Background. Myasthenia gravis is an autoimmune disease that affects the neuromuscular junction, resulting in disrupted transmission. B cells Autoantibodies that target acetylcholine receptors and components like muscle-specific tyrosine kinase, damage it and causing destruction and internalization of AChR. Objective of the study. The goal of this work is to discuss and research AChR+ MG (more common than AChR- MG), by focusing on the clinical and immunological aspects of MG and its subgroups based on their characterization of antigenic targets. Materials and methods: the research is focused on a descriptive and narrative literature reviews about AChR+ MG subtypes based on online resources like PubMed, MGFA official website, MDPI. Results. 1. Ocular MG: Most MG patients with initial ocular symptoms progress to generalized forms within two years, with symptoms as ptosis and diplopia. 2. AChR-MG has early-onset and late-onset subtypes. EOMG occurs before 50 years, often with thymic hyperplasia and positive response to thymectomy. LOMG occurs after 50 years, has no gender predilection, lower thymic hyperplasia prevalence, and a worse response to thymectomy. 3. Thymoma-associated MG: Around 50% of thymoma patients develop AChR-positive MG, with severe muscle weakness, especially in oropharyngeal muscles. Thymoma-MG can occur at any age, usually diagnosed between 40 and 60 years. Thymectomy has varying effectiveness. Conclusions. A unified clinical picture of various MG phenotypes requires a more in-depth study of immunochemical and neurophysiological aspects, which in turn makes it possible to select a more adequate treatment in each of the cases.