Acquired Platelet Dysfunction with Eosinophilia: A Narrative Review

Background. Acquired platelet dysfunction with eosinophilia (APDE) is a transient bleeding disorder initially thought to occur exclusively in Southeast Asia. There are no uniformly agreed diagnostic criteria, and its full clinical features have not been defined. Methods. A literature search was conducted through MEDLINE, EMBASE, and Google Scholar for publications on APDE in order to explore patient demography, epidemiology, diagnostic criteria, and laboratory findings of the disease. Results. Ten retrospective, observational studies, five case series, and 21 case reports were identified with a total of 431 patients. Diagnostic criteria varied, with a two-tier approach for the diagnosis of impaired platelet function. In recent years, cases of APDE have been reported extensively outside of the Malay peninsula. Male patients (243/390, 62.3%) predominated. Their ages ranged from 11 months to 30 years, with only 40 (9.3%) subjects aged 18 years or older. Eosinophilia was absent in 10 to 33% of subjects in a few observational studies. Thrombocytopenia was present in 42 (9.7%) subjects. Parasitic infestation was less common in the new millennium. Spontaneous recovery within six months was the trend, and serious complications were extremely rare. Conclusions. APDE is no longer restricted to Southeast Asia. A uniform set of diagnostic criteria is needed. Clinician awareness followed by reliable but easily available laboratory tests is essential to confirm diagnosis. It is proposed that rapid diagnosis can be accomplished by screening the blood smear for grey platelets by a trained examiner followed by confirmatory platelet aggregometry. National or international collaboration and prospective studies are required to delineate the core and variable clinical and laboratory features of APDE.