Presenting clinical features
A 27-year-old previously healthy male patient (height 176 cm, and weight 79 kg) presented with fever, macrohematuria, and purpura in the lower legs developed 4 days before admission, respectively. He denied drug exposures and recent infectious illness. He had no abdominal pain or diarrhea. Vital signs were normal and physical examination was unremarkable except for petechiae. His mother died of anemia (details unclear). Laboratory findings revealed hemolytic anemia (hemoglobin level: 74 g/L; hematocrit: 22.7%; reticulocyte count: 54×109/L; total bilirubin: 66 mg/L; indirect bilirubin: 51 mg/L; aspartate aminotransferase: 50 U/L; lactate dehydrogenase: 3489 U/L; and haptoglobin: undetectable), thrombocytopenia (platelet count: 9.0×109/L), and renal damage (Urinalysis disclosed a proteinuria score of 2+, a red blood cell count of 8.4 per high-power field, a white blood cell count of 4.4 per high-power field, and serum creatinine: normal). Peripheral smear showed numerous schistocytes (1.2%). Prothrombin time, partial thromboplastin time, and renal function test PT was 12.1 s, APTT was 37.9 s, fibrinogen was 5.25 g/L, factor Xa activity was 115%, and antithrombin III (AT III) activity was 92%, all within normal limits. The laboratory tests showed a Direct antiglobulin test (+), indicating peripheral cytopenias, particularly autoimmune cytopenias (AIC) such as autoimmune thrombocytopenia. Anti-SSA, Jo-52 (+). A bone marrow biopsy was also performed, showing only erythroid hyperplasia without other abnormalities. A diagnosis of ES was made given the evidence of immune-mediated hemolysis with thrombocytopenia in the absence of a known etiology, we administered methylprednisolone pulse therapy with the dose of 500 mg/d for 3 consecutive days. At the following days, he had a drop in his Hgb was from 15.2 g/dL to 7.4 g/dL, with an elevated LDH level soaring to 4136U/L.
Neurologic abnormalities
He remained asymptomatic but over 9 days, he experienced several episodes of headache, blurred vision and minor mental status changes, with fever high up to 38.5. Moreover, Peripheral smear showed an increased number of schistocytes (1.3%) (Fig. 1). PEX through a right femoral venous hemodialysis catheter was carried out daily immediately after the onset of neurologic abnormalities immediately even if ADAMTS-13 levels remained unknown given the high risk of morbidity and mortality of TTP within the first 24 h if plasma replacement therapy is not given[4]. However, because the shortage of serum, we collected 1000ml serum, then added 500ml volume of albumin. The PEX procedure resulted in a dramatic response with improvements. His neurologic abnormalities resolved immediately and did not recur.
On the 3th day post PEX therapy, the PLT rise to 156×109/L with the LDH level down to 478 U/L. Because complete response of PEX was defined by a full resolution of any neurological manifestations and platelet count recovery (>150×109/L) for at least two days based on previous studies and in accordance with international guidelines[5]. Therefore, we continued PEX therapy. On the 4th day post PEX, continuous improvement was noted on the blood test, with platelets peaked to 195×109/L and LDH down to 331 U/L. However, the patient presented with a sudden onset right leg swelling and pain. There were no associated signs or symptoms such as dyspnea or fever. The color Doppler ultrasound demonstrated evidence of DVT in the right lower leg which showed total thrombosis of the right external iliac and femoral veins and nearly total thrombosis of the right popliteal vein (Fig. 2).
We consulted vascular surgeons. Based on their recommendation, the patient underwent inferior vena cava filter placement and catheter thrombolysis and perfusion catheter insertion with continued administration of thrombolytic agent (Fig. 3). At the meantime, PEX session was sustained for another 2 days. The DVT improved markedly, and we shifted to an oral anticoagulant (rivaroxaban). After another twice PEX, he continued to remain asymptomatic, his hematological parameters stabilized with a platelet count of 200 × 10^9/L at discharge and plasma D-dimer levels returned to normal. The patient is now under follow-up in the outpatient clinic and is undertaking rivaroxaban daily, while progressively tapering oral corticosteroids. In a yearly follow-up, there has been no anemia and the platelet count also remains normal to date.