Endocrine Abstracts

Introduction: The autoimmune polyglandular syndrome (APS) is a complex, heterogeneous condition in which autoimmune diseases (AIs) of endocrine and non-endocrine organs can occur. There are four subgroups. The majority of patients are categorized as having APS II or APS III. In APS II, patients have Addison’s disease (AD) and autoimmune thyroid diseases (AITDs) or type I. diabetes mellitus (T1DM), while in the APS III, AITDs are combined with other autoimmune illnesses except AD.

Aim of the study: The main goal of this meta-analysis was to identify the frequency of different AIs in APS II and III in order to provide details for a possible screening protocol.

Method: In Pubmed and Embase databases 479 studies were found with the keywords of APS II and APS III. Among these, 118 records fulfilled the criteria of the study (original reports containing the combination of other AIs). Excluding case-reports, 18 articles containing a total of 1277 (2–254/papers) patients were selected for further analysis. Forrest plot was used for statistical analysis.

Results: The mean age of patients at the time of diagnoses was 34.7 years (95% CI: 22.75 – 46.64). Females were more often affected by APS than males (75% (95% CI: 68% – 81%) vs 25% (95% CI =19% – 32%), P < 0.001). Distinction between APS II and APS III was made in 842 cases, of which 177 and 665 were APS II and III (21.1% vs 78.9%), respectively. The prevalence of Hashimoto’s thyroiditis was significantly higher than of Graves’s disease (39% (95% CI: 17% – 65%) vs 4% (95% CI: 0% – 10%), P=0.001). Two other AIs occurred more often in combination with Hashimoto’s thyroiditis than with Graves’s disease (81% (95% CI: 37% – 100%) vs 3% (95% CI: 0% – 18%), P=0.001). Interestingly, Graves’s disease was never diagnosed in association with more than two other AIs. In APS II, AD coexisted with AITDs, T1DM or the combination of these conditions in 114, 32 and 18 cases, respectively. Above these, 1 other endocrine and 5 non-endocrine organ-specific AIs were reported. In APS III, 2 autoimmune endocrinopathies, 6 non-endocrine organ-specific and 4 systemic AIs were detected in combination with AITDs.

Conclusion: Based on this meta-analysis, AITDs, AD and T1DM are the most common combinations occurring in APS, thus screening for these conditions seems to be reasonable. The association of other AIs is more common in Hashimoto’s thyroiditis compared to Graves’s disease.