title: Associated autoimmune diseases in patients with the Lambert-Eaton myasthenic syndrome and their families.
abstract: In view of the clustering of autoimmune diseases (AIDs), we studied the frequency and nature of additional AIDs in patients with the Lambert-Eaton myasthenic syndrome (LEMS) and their family members, in both small cell lung carcinoma (SCLC) related and non-tumour (NT) related cases. Additional AIDs in patients with LEMS were assessed by interviewing the patient and studying the medical record. Family histories up to second-degree family members were established by interviewing patients, controls and family members. Forty-four patients with LEMS were assessed, of whom eighteen (41%) had SCLC. In the NT group seven patients (27%) had an additional AID, in the SCLC group two (11 %) (p=0.20). Thyroid disorder (five patients) and insulin dependent diabetes mellitus (two patients) were the most common AIDs. AIDs were significantly more frequent in families of patients with NT-LEMS (64%) than in control families (27%) (p=0.002), which was not found in SCLC-LEMS (36%, p=0.53). Affected family members were linked to the NT-LEMS patient through the maternal line in all cases. In conclusion, AIDs were more frequently found in LEMS patients without a tumour and their families, which could not be shown for SCLC-LEMS. This suggests that NT-LEMS shares immunogenetic factors with other AIDs. In families of NT-LEMS, a remarkable preponderance of maternal inheritance was seen, as has been reported previously in myasthenia gravis.
authors.affiliation: Department of Neurology, J3R-166 Leiden University Medical Centre, P. O. Box 9600, 2300, RC Leiden, The Netherlands. pwwirtz@lumc.nl
authors.forename: Paul W
authors.initials: PW
authors.lastname: Wirtz
authors.forename: Jennifer
authors.initials: J
authors.lastname: Bradshaw
authors.forename: Axel R
authors.initials: AR
authors.lastname: Wintzen
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Verschuuren
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000150:complications* / Q000453:epidemiology*; D018288:Carcinoma, Small Cell / Q000150:complications; D005192:Family Health; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D015624:Lambert-Eaton Myasthenic Syndrome / Q000150:complications* / Q000453:epidemiology*; D008175:Lung Neoplasms / Q000150:complications; D008297:Male; D008875:Middle Aged