A Patient with a Previous Diagnosis of Hemoglobin S C Disease

Summary

DOI: 10.1373/clinchem.2008.112326

A 17-year-old African American male presented to the hematology clinic for treatment of sickle cell disease (SCD).1 He had received the diagnosis of hemoglobin (Hb) S/C disease at an outside hospital at the age of 6 years; the diagnosis was confirmed in house at 11 years of age. His disease course had been severe, with frequent pain crises of increasing intensity and 2 episodes of acute chest syndrome requiring hospitalization and multiple blood transfusions.

Complete Article
Commentary: Carlo Brugnara
Commentary: James Hoyer

Student Discussion

Student Discussion Document (pdf)

Elizabeth K. O’Keeffe,¹ Melissa M. Rhodes, ² and Alison Woodworth^1*

¹Departments of Pathology and ²Pediatric Hematology-Oncology, Vanderbilt University Medical Center, Nashville, TN.
*Address correspondence to this author at: Department of Pathology, Vanderbilt University Medical Center, 4918EA TVC, 1301 Medical Center Dr., Nashville, TN, 37232-5310. Fax (615) 343-9563; e-mail [email protected].

Case Description

A 17-year-old African American male presented to the hematology clinic for treatment of sickle cell disease (SCD). He had received the diagnosis of hemoglobin (Hb) S/C disease at an outside hospital at the age of 6 years; the diagnosis was confirmed in house at 11 years of age. His disease course had been severe, with frequent pain crises of increasing intensity and 2 episodes of acute chest syndrome requiring hospitalization and multiple blood transfusions.

The patient’s physical examination was unremarkable: blood pressure, 120/64 mmHg; pulse, 83 beats/min; temperature, 36.9 °C. Laboratory results were as follows: white blood cell count, 11.8 X 109/L [reference interval (RI), 3.9–10.3 X 109/L]; Hb, 6.39 mmol/L (RI, 8.68–10.8 mmol/L); packed cell volume, 0.28 (RI, 0.42–0.50); red blood cell count, 3.59 X 1012/L (RI, 4.5–6.0 X 1012/L); platelet count, 417 X 109/L (RI, 135–370 X 109/L); mean corpuscular volume, 78 fL (RI, 83–102 fL); mean corpuscular Hb, 28.7 pg (RI, 27–31 pg); mean corpuscular Hb count, 368 g/L (RI, 320–340 g/L); red cell distribution width, 17.3% (RI, 11.5%–14.5%); and absolute reticulocyte count, 0.115 (RI, 0.02–0.10). A peripheral blood smear showed scattered target and sickle cells, rare nucleated red cells, and mild anisopoikilocytosis. Results for the qualitative sickle cell solubility test were positive. Considering the severe disease course, Hb analysis by HPLC and isoelectric focusing (IEF) was ordered (Fig. 1).

Fig 1 IEF and HPLC analysis of Hbs in the patient's sample

Questions to Consider

How do various hemoglobinopathies differ clinically?
What laboratory tests should be used to distinguish different hemoglobinopathies?
Why is it important to use at least two different Hb separations techniques for the diagnosis of a hemoglobinopathy?
When should a patient with a diagnosis of Hb S/C be re-evaluated for alternative hemoglobinopathies?
What treatment strategies are used for patients with different sickle cell diseases? Does this differ from other hemoglobinopathies?

Final Publication and Comments

The final published version with discussion and comments from the experts appears in the June 2009 issue of Clinical Chemistry, approximately 3-4 weeks after the Student Discussion is posted.

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