PF712 PHYSICIANS’ PERCEPTIONS ON CAUSES OF PRIMARY AND SECONDARY ITP AND LEADING CAUSES OF MISDIAGNOSIS: RESULTS FROM THE ITP WORLD IMPACT SURVEY (I‐WISH)
Authors: Bussel J.B. , Tomiyama Y. , Michel M. , Provan D. , Hou M. , Santoro C. , Kruse A. , Kruse C. , Morgan M. , Lovrencic B. , Bailey T. , Stankovic M. , Ghanima W. 
Published: June 2019

Background:

Immune thrombocytopenia (ITP) is a heterogeneous syndrome with variable clinical manifestations across patients (pts), which makes diagnosis challenging and requires tailored investigations. There is a need for improved accuracy and novel testing in diagnosing ITP and better use of existing tests, e.g. reticulated platelets, platelet antibodies.

Aims:

I‐WISh studied the burden of ITP and its impact on quality of life using a global pt and physicians sampling frame. This analysis reports physicians’ perspectives on the difficulties inherent in ITP diagnosis.

Methods:

I‐WISh is a cross‐sectional survey of 1507 ITP pts and 472 physicians across 13 countries. Participants (pts and physicians) completed a 30‐minute online survey that included demographics, signs and symptoms, impact of symptoms, and pt–physician relationships. A steering committee of expert physicians and pt advocacy ITP specialists designed and endorsed the survey materials. All physician‐reported data were collected from a single physician survey, which asked physicians about their experience and perceptions of managing ITP patients. Physicians assigned a rank of 1, 2, or 3 from a list of 15 conditions that could be misdiagnosed as ITP.

Results:

472 physicians with a mean number of ITP pts (SD) of 34 (50) and mean (SD) of 18 (36) newly diagnosed pts in the past year completed the survey. According to physicians’ recollections, 72% of ITP pts have primary ITP and the remaining 28% have secondary ITP. The survey revealed that exclusion of other disorders was perceived as the leading cause of delays in making an accurate diagnosis of ITP (68%). 53% of physicians indicated misdiagnosis as a contributing factor in delayed diagnosis, with 71% reporting that pts were misdiagnosed 1–25% of the time. Other contributors to delayed diagnosis were access to diagnostic examination (55%) and time to refer pts to a specialist (58%). Out of 441 responses, causes of secondary ITP featured in the top 3 were systemic lupus erythematosus (46%), drug‐induced thrombocytopenia (DIT; 46%), chronic lymphocytic leukemia (CLL; 45%), antiphospholipid syndrome (30%), hepatitis C virus (26%), autoimmune lymphoproliferative syndrome (post‐treatment) (ALPS; 23%), Helicobacter pylori infection (20%), Evans syndrome (17%), and HIV (13%) (Fig). DIT (67%) was the most frequent condition misdiagnosed as ITP, followed by aplastic anemia/myelodysplastic syndromes (MDS; 49%), liver disease (46%), hypersplenism (38%), and leukemia (29%) (Fig). 18% of pts reported being first diagnosed with another condition.

Summary/Conclusion:

Accurate diagnosis of ITP is difficult. No formula exists allowing accurate diagnosis in all locations and no testing is universally considered to be specific or sensitive. Secondary ITP diagnosis in as many as 28% of ITP pts adds to the difficulties of diagnosing primary ITP; this number is ∼10% higher than previous estimates (Cines et al. Hematol Oncol Clin North Am 2009;129:818). Given that the only positive diagnosis of ITP is response to ITP‐specific treatment, this would nonetheless not exclude secondary ITP. Surprisingly, the leading misdiagnosis being DIT highlights the need for better testing of DIT (currently unavailable anywhere) and the need to replace all medications the patient is taking at diagnosis. Liver disease needs to be suspected early, and testing for this could include ultrasonography (Rajan et al. Brit J Haematol 2005;23:1155). The high rate of secondary ITP and absence of specific testing for ITP contribute to the difficulties with diagnosis.

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