Microangiopathic Hemolytic Anemia and Thrombocytopenia: Questions

Part 2: Management

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Hematology Expert Review is an occasional feature that includes a case report followed by questions, answers, and expert commentary. In the July 25 issue of The ASCO Post, part 1 of a case report was published and focused on diagnosis (see summary below). Here, in part 2, the management of this case is discussed. 

Summary of Part 1

A 26-year-old woman presented to labor and delivery triage with fatigue, heavy vaginal bleeding, and gastrointestinal upset on postpartum day 8 after vaginal delivery. Prior to presentation, she reported diarrhea and nausea with nonbilious, nonbloody emesis, which since had resolved. She had left upper quadrant pain, which worsened with deep inspiration. On review of systems, she experienced dizziness, with no syncopal episodes. She denied fever or chills, bleeding gums or easy bruising, dysuria, or vaginal discharge other than blood.

Her medical history was notable for sickle cell trait, scoliosis, and chronic borderline hypertension.Following physical examination and evaluation of laboratory values, doctors performed peripheral blood smear examination. The most likely diagnosis was determined as thrombotic thrombocytopenic purpura or hemolytic uremic syndrome.

ADAMTS13 analysis was performed to aid in making the correct diagnosis (ADAMTS13 is a metalloproteinase present in the blood responsible for cleaving ultralarge von Willebrand factor multimers into smaller-sized multimers. Deficiency results in thrombotic thrombocytopenic purpura. Activity levels less than 10% are considered severely low.) This patient’s ADAMTS13 level was less than 10% of normal, thus confirming the diagnosis of thrombocytopenic purpura. Part 2 of this case report, which continues here, focuses on management of this patient.

Continued Case Study

Plasma exchange was continued until platelets peaked at 170,000/μL, at which point it was stopped. Two days after stopping therapeutic plasma exchange, the patient developed fever, epistaxis, and oozing at the plasmapheresis catheter site.

On examination, she was sleepy but arousable and had a high fever of 102˚ F with chills. She became hemodynamically unstable, with a heart rate of 160 beats/min and a blood pressure of 60/40 mm Hg.

Key Laboratory Results

Emergency laboratory results revealed sodium 135 mmol/L, potassium 5.5 mmol/L, chloride 111 mmol/L, bicarbonate 18 mmol/L, urea nitrogen 45 mg/dL, creatinine 2.6 mg/dL, and glucose 100 mg/dL.

The alanine transaminase was 20 U/L; aspartate transaminase, 45 U/L; total bilirubin, 2.0 mg/dL; direct bilirubin, 0.6 mg/dL; and albumin, 1.4 g/dL.

The white blood cell count was 21,000/μL with predominant neutrophils. The hemoglobin was 11.0 g/dL, hematocrit was 33.0%, and platelets dropped to 65,000/μL.

The prothrombin time was 21.1 seconds, activated partial thromboplastin time was 55.7 seconds, and international normalized ratio was 4. Fibrinogen was 80 mg/dL. D-dimer level was greater than 4,000 times the upper limit of normal.

Examination of the peripheral blood smear film revealed schistocytes, anemia, and thrombocytopenia. At this point, fluid resuscitation was started.

Question 1

What is the best first step in management of this patient?

A. Assay for mutations in complement regulatory protein genes

B. Check blood ADAMTS13 (also known as von Willebrand factor–cleaving protease) level

C. Start plasma exchange

Question 2

In the current era, the majority of patients with thrombotic thrombocytopenic purpura will receive therapeutic plasma exchange before the development of ­“classic pentad”?

A. True

B. False


Question 3

What is the next best step in the management of this patient?

A. Emergency blood cultures and initiation of broad-spectrum antibiotics

B. Emergency plasma exchange

C. Eculizumab

Click here for answers and expert discussion.



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Microangiopathic Hemolytic Anemia and Thrombocytopenia Answers

Question 1: What is the best first step in management of this patient?

Correct Answer: C. Start plasma exchange.

Expert Perspective

Although distinguishing among thrombotic thrombocytopenic purpura, typical hemolytic uremic syndrome, and atypical hemolytic uremic syndrome (see Table 1 in the...