Reducing the diagnostic delay in Antiphospholipid Syndrome over time: a real world observation

Antiphospholipid Syndrome (APS) is a rare autoimmune disorder with an estimated prevalence of 40-50 cases per 100.000 persons. Patients suffering from low prevalence diseases are more likely to face diagnostic challenges, given the limited knowledge of most clinicians. The main aim of this study was to investigate the time between symptoms occurrence and the diagnosis of APS patients using the Piedmont and Aosta Valley Rare Disease Registry. Secondly, to evaluate the individual impact of the diagnostic gap by gathering patients' personal experiences through a self-administered questionnaire.

Data from the Piedmont and Aosta Valley Rare Disease Registry was used. In addition, personal experiences were analyzed through a self-administered questionnaire. A total of 740 APS patients included in the Piedmont and Aosta Valley Rare Disease Registry were analyzed. Diagnostic delay (as defined by time between symptoms' occurrence and the diagnosis of APS) was significantly reduced over time. In particular, when comparing the diagnostic delay between patients diagnosed between 1983 and 1999 and patients diagnosed between 2000 and 2015, we found a significant statistical difference (Mann-Whithey U Test; mean rank 1216.6 vs. 1066.9, respectively; p < 0.0001). When analyzing the self-administered questionnaires, patients with a perception of having suffered for a diagnostic delay had a higher prevalence of symptoms suggestive of an autoimmune condition but not highly suggestive of APS (45%), followed by "extra criteria" APS manifestation (30%) and by thrombotic events (25%). The first clinical manifestation of patients who did not have the perception of having suffered a diagnostic delay was thrombotic events (45.5%), followed by autoimmune manifestation not linked to APS (45.5%), and "extra criteria" APS manifestations (9%).

While the diagnostic delay of APS has been reduced during the last years, the time between symptoms occurrence and the diagnosis of rare diseases still represents a critical issue to be addressed in order to prevent major complications.