title: Penicillamine-induced myasthenia in rheumatoid arthritis: its clinical and genetic features.
abstract: The clinical features and genetic background of 18 patients with rheumatoid arthritis were investigated following the development of penicillamine-induced myasthenia (PIM). The initial myasthenia symptoms in all patients consisted of variable diplopia and/or ptosis with progression to a more generalized involvement in 7 of them. No clinical, humoral, or genetic factor was determined which would allow identification of individuals developing generalized as opposed to ocular myasthenia. Withdrawal of penicillamine was associated over 4-60 weeks with a slow resolution of symptoms, facilitated in 12 patients by the use of anticholinesterase agents. In 2 patients a persistent partial unilateral ptosis remains after 15 and 25 months, while in a further patient diplopia is present 42 months after resolution of the other myasthenic symptoms. The patients with PIM when compared with a healthy 'control' population had a significant increase in HLA Dr1 (p corr less than 0.005) and an absence of HLA Dr 3. A genetic susceptibility to the development of PIM, distinct from that observed in myasthenia gravis of spontaneous onset, is suggested by this abnormal distribution of HLA Dr antigens.
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000235:genetics; D003165:Complement System Proteins / Q000032:analysis; D005260:Female; D006680:HLA Antigens / Q000032:analysis; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens; D015798:HLA-DR1 Antigen; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000139:chemically induced / Q000235:genetics*; D010396:Penicillamine / Q000009:adverse effects*
chemical_list: D006680:HLA Antigens; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens; D015798:HLA-DR1 Antigen; D000949:Histocompatibility Antigens Class II; D003165:Complement System Proteins; D010396:Penicillamine