A 23-year-old man comes to the physician saying that his eyes often have a yellowish hue. He considers himself healthy, eats well, and exercises regularly. He does not use tobacco, alcohol, or illicit drugs. The patient was adopted at a young age and does not know his biological family history.
Vital signs are within normal limits. The tip of the spleen is palpable on inspiration. The remainder of the physical examination is unremarkable.
Laboratory values are as follows:

Blood smear shows 3-5 spherocytes per high-power field.
Which of the following is the best next step in the evaluation of this patient?

Question

A 23-year-old man comes to the physician saying that his eyes often have a yellowish hue.  He considers himself healthy, eats well, and exercises regularly.  He does not use tobacco, alcohol, or illicit drugs.  The patient was adopted at a young age and does not know his biological family history.
Vital signs are within normal limits.  The tip of the spleen is palpable on inspiration.  The remainder of the physical examination is unremarkable.
Laboratory values are as follows:

Blood smear shows 3-5 spherocytes per high-power field.
Which of the following is the best next step in the evaluation of this patient?

Quizplus · Accepted Answer

Spherocytes can occur in a variety of clinical conditions, including autoimmune hemolytic anemia (AIHA), hereditary spherocytosis (HS), clostridial sepsis, snake bites, glucose-6-phosphate dehydrogenase deficiency, and microangiopathic hemolytic anemia. However, this patient's clinical presentation (anemia, jaundice, and splenomegaly) suggests AIHA or HS. The direct antiglobulin test (DAT or Coombs) helps differentiate between the 2 conditions as it is negative in HS but positive in AIHA. hereditary spherocytosis HS is due to altered genes encoding for red blood cell (RBC) membrane proteins, which leads to RBC instability and phagocytosis by the spleen. It is autosomal dominant in 75% of cases. Patients often present with varying degrees of chronic hemolytic anemia, jaundice, and splenomegaly. They may present with increased hemolysis due to stress/infections, aplastic crisis (eg, parvovirus B19 infection), or megaloblastic anemia due to increased folate requirement. Bilirubin gallstone formation often occurs in adult patients and requires cholecystectomy. Laboratory testing shows anemia, reticulocytosis, elevated mean cell hemoglobin concentration, and increased red cell distribution width. Peripheral smear shows spherocytosis in varying degrees depending on disease severity. The diagnosis is confirmed with the eosin-5-maleimide binding (flow cytometry) or acidified glycerol lysis tests. Treatment of HS includes RBC transfusion for symptomatic anemia, folic acid supplementation, and splenectomy for severe cases. (Choice A) A bone marrow biopsy is performed to evaluate malignancy, pancytopenia, suspected myelodysplastic syndrome, or bone marrow fibrosis. It may be used for evaluating anemia once all other noninvasive workup is negative. (Choice C) Hemoglobin electrophoresis diagnoses hemoglobinopathies, which can present with microcytic anemia and increased red cell distribution width. However, they usually do not cause spherocytosis. (Choice D) Cobalamin (vitamin B12) deficiency usually presents with macrocytic anemia and peripheral blood smear showing hypersegmented neutrophils instead of spherocytes. (Choice E) Serum protein electrophoresis is used to fractionate serum proteins by size and electrical charge. It is used for diagnosing nephrotic syndrome, mono- and polyclonal gammopathies, and liver disease (eg, alpha-1 antitrypsin deficiency). Educational objective: The 2 most common causes of spherocytosis are autoimmune hemolytic anemia and hereditary spherocytosis (HS). The direct antiglobulin test (Coombs) is negative in HS patients. The diagnosis of HS is confirmed with the eosin-5-maleimide binding (flow cytometry) or acidified glycerol lysis tests. Treatment of HS includes red blood cell transfusion for symptomatic anemia, folic acid supplementation, and splenectomy for severe cases. __________ References: Guidelines for the diagnosis and management of hereditary spherocytosis (http://www.ncbi.nlm.nih.gov/pubmed/22055020)

A 23-Year-Old Man Comes to the Physician Saying That His