Unusual presentation of acquired thrombotic thrombocytopenic purpura (TTP) versus catastrophic antiphospholipid syndrome in a patient with Moya-Moya disease, case report, and literature review.

Coincidences in medicine are not so common. We are presenting a case of a patient diagnosed with Moya-Moya disease and antiphospholipid syndrome (APS) who presented with clinical and laboratory characteristics of catastrophic APS versus TTP. The diagnosis was a challenge because characteristics were overlapping. Nevertheless, a decision to treat the patient for TTP was made with afterward improvement. MMD has been associated with multiple immune disorders; however, only one case of acquired thrombotic thrombocytopenic purpura has been documented in association with this disease. None has been associated with catastrophic antiphospholipid syndrome. We are presenting a challenging case where all these three medical conditions were present at the same time.

A Challenging Diagnosis of Febrile Pancytopenia in a Patient With a History of Autoimmune Disease.

Pancytopenia is a hematologic condition characterized by a decrease in all three peripheral blood cell lines. There are many causes of pancytopenia, and the proper approach is required for accurate diagnosis. Brucellosis and systemic lupus erythematosus (SLE) are both diseases that can initially present as pancytopenia, both of which require a targeted workup to diagnose. Due to the immune system's complexity, many distinct diseases may have similar symptomatology. Furthermore, infections and rheumatological diseases can stimulate the same molecular pathways and trigger T and B cells. This creates a cross-reactivity between microbial peptides and self-peptides, allowing the spread of microbial-specific T cells that can also respond to self-peptides. Brucellosis has broad clinical manifestations, often mimicking many other diseases, such as rheumatoid arthritis, sarcoidosis, and SLE. In addition, brucellosis-induced autoantibody production has been described as a triggering factor for immunologic reactions, elevating rheumatological markers by a poorly understood mechanism. Finally, SLE is a well-known medical condition that can mimic several medical conditions, including brucellosis.  We present a case of a young patient who was admitted with febrile pancytopenia. The patient also had IgM antibodies positive for brucellosis and high immune markers for SLE. She was treated for both diseases, and afterward, in retrospect, it was confirmed that the patient did not have acute brucellosis.