A patient with a previous diagnosis of hemoglobin S/C disease with an unusually severe disease course.

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 10/L [reference interval (RI), 3.9 –10.3 10/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 10/L (RI, 4.5– 6.0 10/L); platelet count, 417 10/L (RI, 135–370 10/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).