To the editor: A 60-year-old male was evaluated for episodes of gingival bleed. Past medical history was significant for hypertension currently treated with clonidine and aliskiren and early stage prostate cancer. Social and family histories were noncontributory. Review of systems was negative except for bleeding. Physical examination was unremarkable. Platelet count was 8 3 10 9 /l and peripheral smear demonstrated thrombocytopenia with few large platelets. Immune Thrombocytopenic Purpura (ITP) was diagnosed, and the patient was treated with prednisone 40 mg/day with significant improvement in his platelet count. Prednisone was then tapered to 5 mg/day.
Six months later, the patient developed gingival bleed, chest pain, shortness of breath, and hematuria. Physical examination revealed elevated blood pressure (200/104 mm of Hg), gingival bleeding, and a hematoma of the tongue. Laboratory tests showed platelet count 6 3 10 9 /l, Lactate Dehydrogenase (LDH) 1348 u/l, Antinuclear Antibody (ANA) titers 1:160, and total bilirubin 6 mg/dl. Coagulation profile, hepatitis panel, Thyroid-stimulating hormone (TSH), Human immunodeficiency virus (HIV), Rh factor, and direct antiglobulin test were negative. The diagnosis of ITP, myocardial infarction, and uncontrolled hypertension was made. Prednisone was increased to 60 mg/day, and blood pressure control was optimized. On admission Day 2, the patient developed altered mental status and fever. Computerized Axial Tomography (CAT) scan of head revealed intracranial bleed. His hemoglobin level fell by 2 g/dl and serum creatinine increased. Peripheral smear confirmed the diagnosis of Thrombotic Thrombocytopenic Purpura (TTP). Plasmapheresis was initiated, mental status returned to baseline, and renal function remained stable. ADAMTS -13 (Is a metalloproteinase also known as von Willebrand factor-cleaving Protease) activity obtained before plasmapheresis was 12%, and von Willebrand factor cleaving inhibitor level was 1.4 (normal less than 0.4). Plasmapheresis was continued for 12 exchanges with modest recovery of platelet count from. The patient remained anemic, LDH levels remained high, and 21 schistocytes persisted on peripheral blood smear. Therapy with rituximab (4 weekly doses of 375 mg/m 2 ), methylprednisone (1 mg/kg/day) and intravenous immunoglobulin G was initiated. After the fourth course of this regimen, the platelet count was 107 3 10 9 /L, LDH levels decreased, the hematocrit remained stable, and peripheral smear showed no fragmented red blood cells. The patient was successfully tapered off prednisone and has remained well.
TTP and ITP existing in the same patient are uncommon. Seventeen cases have been reported in the literature with both conditions occurring at different times or concurrently (only one case). Baron et al. [1] reviewed 11 cases of TTP, six of which had an underlying autoimmune disorder. Baron suggested that these six cases represented a distinct clinical syndrome, ''mixed immune thrombocytopenia,'' due to disturbed immune regulation.
Our patient initially presented with isolated thrombocytopenia and positive ANA titers suggestive an immune-mediated disease that responded transiently to steroids. On readmission, he was diagnosed with TTP and started on appropriate therapy with good clinical outcome.
In conclusion, emphasis should be placed on a thorough re-evaluation of each recurrence of thrombocytopenia. Overlapping of these two distinct clinical entities may be misleading and can delay appropriate treatment. As evidenced by existing literature, the patient who presents with an initial episode of either ITP or TTP, may subsequently present with either of these syndromes at relapse.