Outcome in hemoglobin SC disease: A four‐decade observational study of clinical, hematologic, and genetic factors

Abstract

Over the past 40 years, we observed 284 subjects with hemoglobin SC disease (Hb SC) for 2,837 person-years. We examined the association of the course of clinical events with hematologic and genetic factors. The mean entry age was 21 years, although 15% entered before one year of age. The mean Hb concentration was 11.3 g/dL, the mean fetal hemoglobin was 2.5%, and the mean MCV was 84.4 fL. Twenty-five subjects died at a median age of 37 years. Chronic organ-specific complications occurred in 112 subjects (39.4%), with advanced retinopathy in 65 subjects (22.9%) and osteonecrosis (avascular necrosis) in 42 subjects (14.8%). We identified the ␤-globin haplotypes in 82 subjects and the ␣-gene status in 79. Twenty-nine percent had ␣-thalassemia-2. The ␤ CI haplotype was present in 85.4%. We found a decreased incidence of retinopathy in the ␤ CI subjects compared to the non-␤ CI subjects (33% vs. 67%; P = 0.049) with a later mean onset age (29 years vs. 21 years; log-rank test, P = 0.026). We also found a consistent pattern of decreased morbidity in subjects who had ␣-thalassemia-2 in comparison to those who did not. We found a reduced risk of chronic organ-specific complications (log-rank test, P = 0.003), lower incidence of sickle crisis (48% vs. 80%, P = 0.001), later onset of gallbladder disease (age of onset: 55 years vs. 34 years; P = 0.055), and lower risk of osteonecrosis (log-rank test, P = 0.024). Our findings suggest that Hb SC subjects who have not inherited ␣-thalassemia-2 might benefit from erythrocyte rehydration therapy. Am. J. Hematol. 70:206-215, 2002.

The Prevalence of Avascular Necrosis in Adults With Sickle Cell Disease in King Fahad Hospital.

“…Of 220 SCA patients attended at King Fahad Hospital in a period of 7 years, 16 (7.3%) had AVN. Lower than the prevalence reported by Milner in 1991 (9.8%), and it is far below the more recent studies like the study was done in the USA by Darleen R. Powars which found that (15%) of subjects have AVN, the study in Kuwait by R. Marouf reported an increase in the prevalence to (48.6%), and in London by H. E. Ware the prevalence reached (41%) [15,21,17,22]. The recent studies claim that this increase in prevalence is due to advancement of diagnosis and radiological imaging.…”

Mutations and polymorphisms in hemoglobin genes and the risk of pulmonary hypertension and death in sickle cell disease

“…Specifically, Hb SC has a milder clinical course relative to homozygous SCD which is characterized by fewer vaso-occlusive events, a less intense hemolytic anemia, less frequent priapism, and a nearly normal average lifespan [2,6,33]. However, some vaso-occlusive manifestations including retinopathy and osteonecrosis may be more frequent in SC disease [34,35]. A similar protective association with pulmonary hypertension is also likely to be present in Sb 1 thalassemia.…”

Hemoglobin sickle cell disease complications: a clinical study of 179 cases

“…Among the 69% of foreign born patients, the mean duration of residence in France was 13.8 years and the mean duration of follow up at the center was 5.1 years. Fifty-eight percent of female patients had been pregnant with a mean of 1.9 children per woman and 32 spontaneous abortions were reported in 12 females (5 multiple abortions, range [2][3][4][5][6][7][8][9][10][11]. High body mass index (≥25kg/m 2 ) and blood hypertension (> 130/80 mmHg) were reported in 33% and 14% of HbSC patients, respectively.…”

“…5 Curiously, whereas SCA clinical features have been extensively studied, very few studies have been dedicated specifically to HbSC disease. 3,[6][7][8][9] Indeed, HbSC disease is generally considered to be a variant of SCA, sharing similar clinical complications though with a milder severity and a lower frequency. 7 Therefore, the aim of our study was to examine the specific clinical and biological features of HbSC disease in a single center patient cohort.…”