title: Long-term follow-up of organ-specific antibodies and related organ dysfunction in type 1 diabetes mellitus.
abstract: OBJECTIVE
  Diabetes mellitus type 1 (DM1) is associated with other autoimmune disorders. To our knowledge, there are no longitudinal data considering the long-term clinical relevance of organ-specific antibodies (OS-Ab) in DM1 patients. We performed a long-term retrospective longitudinal study in order to investigate the presence and diagnostic accuracy (positive predictive value: PPV and negative predictive value: NPV) of OS-Ab in DM1 patients.
  
  
  METHODS
  In a retrospective longitudinal study, the presence of OS-Ab and related organ function were analysed in 396 DM1 patients (184 F/212 M, age 44 ± 13 years, age at onset of DM1 21 ± 13 years), with a median follow-up time of 23 ± 10 years.
  
  
  RESULTS
  OS-Ab frequencies at baseline were: antibodies against thyroglobulin (Tg-Ab) 4.3%, antibodies against thyroid peroxidase (TPO-Ab) 8.1%, Tg- and/or TPO-Ab 10.4%, antibodies against parietal cells (PCA) 5.8% and antibodies against adrenal cortex (ACA) 0.5%. The occurrence of (sub)clinical hypothyroidism was higher in patients with Tg-Ab (47%) or TPO-Ab (42%) than in those without these antibodies (6.2 and 5.1%, respectively, p<0.001). PPV and NPV for Tg-Ab were 0.60 and 0.88, respectively, for TPO -Ab 0.54 and 0.91. Also in patients with PCA, organ dysfunction occurred more often (61%) than in patients without PCA (9.7%, p<0.001). PPV for PCA was 0.61 and NPV 0.90. NPV and PPV for ACA could not be calculated because of the low prevalence.
  
  
  CONCLUSIONS
  Long-term follow-up of 396 DM1 patients shows that the presence of thyroid antibodies and/ or parietal cell antibodies is clearly associated with dysfunction of the corresponding organ.
authors.affiliation: Department of Endocrinology, Leiden University Medical Center, Leiden, the Netherlands. l.degraaff@erasmusmc.nl
authors.forename: L C G
authors.initials: LC
authors.lastname: de Graaff
authors.forename: P
authors.initials: P
authors.lastname: Martín-Martorell
authors.forename: J
authors.initials: J
authors.lastname: Baan
authors.forename: B
authors.initials: B
authors.lastname: Ballieux
authors.forename: J W A
authors.initials: JW
authors.lastname: Smit
authors.forename: J K
authors.initials: JK
authors.lastname: Radder
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D001323:Autoantibodies / Q000276:immunology; D001327:Autoimmune Diseases / Q000453:epidemiology / Q000276:immunology*; D002648:Child; D015897:Comorbidity; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology / Q000276:immunology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D013961:Thyroid Gland / Q000276:immunology* / Q000503:physiopathology; D055815:Young Adult
chemical_list: D001323:Autoantibodies