Secondary immune thrombocytopenia (ITP) as an initial presentation of Whipple's disease

Immune thrombocytopenia (ITP) is a heterogeneous autoimmune disease characterized by low platelet count that has been associated with a number of chronic infections but rarely described as a manifestation of Whipple's disease (WD). We present a case of Whipple's disease in a patient initially diagnosed with ITP. A 46-year old male in the fifth decade of life presented with presumed idiopathic ITP and was treated with several therapies including corticosteroids, rituximab, and thrombopoietin receptor agonists. Several years later, he developed weight loss and worsening arthralgias. He was found to have evidence of WD in a jejunal lymph node, the duodenum, and the cerebral spinal fluid (CSF). His diagnosis of WD, as a cause of secondary ITP, came a full 8 years after he was discovered to have thrombocytopenia and over 4 years after he was diagnosed with ITP. WD is an uncommon, multiorgan system disease caused by the actinomycete Tropheryma whipplei. Whipple's disease presents a diagnostic challenge due to the wide array of possible presenting clinical manifestations, as well as a prolonged time course with separation of symptoms over many years. While T. whipplei is ubiquitous in the environment, few individuals develop clinical disease, raising the prospect that select immunodeficiencies, both singular or in combination, may play a role in infection. While rare, in the appropriate clinical setting, one should consider infection with T. whipplei in addition to other chronic infections as a cause of secondary ITP regardless of how long ago the diagnosis of ITP was made.