[Late onset primary antiphospholipid syndrome in the older adult]

Antiphospholipid syndrome (APS) is a systemic autoimmune disease, characterized by arterial or venous thrombosis and/or obstetric events in the presence of antiphospholipid antibodies (aPL). It is usually diagnosed in patients between the ages of 15 and 50 years, and there are 5 new cases per 100,000 people per year. It is reported a case of APS, which it is present in an older adult with an unusual clinical manifestation.

Female patient without history of autoimmune diseases, at age 70 presented hemolytic anemia, Coombs direct positive, classified as autoimmune hemolytic anemia (AHAI) Coombs+, and severe thrombocytopenia. Other immunological, infectious, and lymphoid proliferative disorders and solid tumors were ruled out. Fisher-Evans syndrome (FES) was diagnosed with good response to treatment. Three months later, the patient presented deep venous thrombosis in the left pelvic limb, positive antiphospholipid antibodies (aPL) and positive aloantibodies were determined, establishing the diagnosis of primary APS and FES as its initial manifestation. Since then, the patient has been in treatment with acenocoumarol and prednisone without new recurrences of thrombosis, with persistence of moderate thrombocytopenia, without adding another clinical manifestation in 15 years of follow-up.

The unusual presentation of this disease in older adults with comorbidities should not rule out the possibility of the development of a primary autoimmune disease, so it should be considered for diagnosis in this age group.