Hemoglobin SC disease complications : a clinical study of 179 cases

Background. Hemoglobin SC disease is one of the most frequent hemoglobinopathy. Surprisingly, few studies were dedicated to this disease, currently considered as a mild variant of homozygous sickle cell disease. The aim of this study was to update our knowledge about hemoglobin SC disease. Design and Methods. We conducted this study in a monocentric series of 179 patients. Clinical and biological data were collected, with a special concern for the assessment of pulmonary arterial hypertension and nephropathy. Results. Hemoglobin SC diagnosis was delayed and performed in adulthood in 29% of cases. Hospitalized painful vasoocclusive crisis, acute chest syndrome and priapism had a prevalence of 36%, 20% and 20% respectively. The most common chronic organ complications were retinopathy and sensorineural otologic disorders occurring in 70% and 29% of cases. Indeed, prevalence of complications reported in homozygous sickle cell disease such as nephropathy, suspicion of pulmonary hypertension, strokes and leg ulcers was rather low (13%, 4% and 1% respectively). Phlebotomy performed in 36% of this population (baseline hemoglobin level: 11.5 g/dL), prevented acute events recurrence in 71% of cases. Conclusions. Our data suggest that hemoglobin SC disease should not be considered as a mild form of sickle cell anemia but as a genuine disease with a special emphasis on viscosity-associated otologic and ophthalmologic disorders and with a low prevalence of vasculopathy (strokes, pulmonary hypertension, ulcers and nephropathy). Phlebotomy was useful to reduce acute events and a wider use of this procedure should be further investigated. DOI: 10.3324/haematol.2011.055202