Microalbuminuria in sickle cell disease.

The kidney is involved in virtually all individuals who inherit the sickle cell form of hemoglobin. Though asymptomatic and relatively common, proteinuria in patients with sickle cell anemia (SS) over 40 years old is associated with reduced creatinine clearance. The subclinical increase in urinary albumin is termed microalbuminuria and is a marker of preclinical glomerular damage. The aim of the present study was to determine the presence of microalbuminuria measured by radioimmunoassay in patients with sickle cell disease. The study included 41 patients with SS, 11 patients with hemoglobin SC disease, 4 subjects with S beta-thalassemia and 10 normal controls. All subjects were teenagers or adults. Sixteen SS patients (40%) and 1 SC (9%) and 1 S beta (25%) patient presented mean urinary albumin excretion (UAE) above normal values (30 mg/l. No correlation was observed between UAE and age, creatinine clearance, hemoglobin level or %HbF. These parameters, as well as the presence of leg ulcers, were not significantly different between SS patients with and without UAE above 30 mg/dl. The high prevalence of microalbuminuria in patients with sickle cell anemia indicates that glomerular damage is common. The connection between microalbuminuria and clinical nephropathy has been demonstrated in diabetes and may indicate a sign of early disease rather than a marker for susceptibility. Thus, microalbuminuria may be an early indicator of glomerular damage for patients with sickle cell disease.

Microalbuminuria in sickle cell disease

The kidney is involved in virtually all individuals who inherit the suckle cell form of hemoglobin. though asymptomatic and relatively common, proteinuria in patients with sickle cell anemia (SS) over 40 years old is associated with reduced creatinine clearance. The subclinical incrase in urinary albumin is termed microalbuminuria and is a marker of preclinical glomerular damage. The aim of the present study was to determine the presence of microalbuminuria measured by radioimmunoassay in patients with sickle cell disease. The study inclused 41 patients with SS, 11 patients with hemoglobin SC disease, 4 subjects with Sß-thalassemia and 10 normal controls. All subjects were teenagers or adults. Sixteen SS patients (40%) and 1 SC (9%) and 1 Sß (25%) patient presented mean urinary albumin excretion (UAE) above normal values (30 mg/l). No correlation was observed between UAE and age, creatinine clearance, hemoglobin level or %HbF. These parameters, as well as the presence of ulcers, were not significantly differente between SS patients with and without UAE above 30 mg/dl. The high prevalence of microalbuminuria in patient with sickle cell anemia indicates that glomerular damage is common. The connection between microalbuminuria and clinical neplhropathy has been demonstrated in diabetes and may indicate a sign of early disease rather than a marker for susceptibility. Thus, microalbuminuria may be an early indicator of flomerular damage for patients with sickle cell disease

Whole body protein turnover and resting metabolic rate in homozygous sickle cell disease.

1. Whole body protein turnover and resting metabolic rate were measured in six adults with homozygous sickle cell disease (genotype HbSS) and in six normal adults (genotype HbAA) of similar age. 2. Turnover was measured with prime/intermittent oral doses of [15N]glycine over 18 h and resting energy expenditure was measured by indirect calorimetry. 3. In HbSS, nitrogen flux (0.9 +/- 0.08 g day-1), protein synthesis (6.0 +/- 0.5 g day-1 kg-1) and protein degradation (5.6 +/- 0.5 g day-1 kg-1) were significantly increased compared with HbAA nitrogen (flux 0.5 +/- 0.02 g day-1 kg-1, protein synthesis 3.2 +/- 0.2 g day-1 kg-1 and protein degradation 2.8 +/- 0.2 g day-1 kg-1). 4. Resting energy expenditure was significantly higher in HbSS compared with HbAA when expressed per unit of body weight (115 +/- 3 and 94 +/- 4 kJ day-1 kg-1, respectively) or weight 0.75(317 +/- 6 and 269 +/- 8 kJ day-1 kg-0.75, respectively). 5. The increase in protein turnover and energy expenditure suggest that patients with HbSS exist in a hypermetabolic state that requires greater dietary energy compared with HbAA.

Whole body protein turnover and resting metabolic rate in homozygous sickle cell disease

Whole body protein turnover and resting metabolic rate were measured in six adults with homozyguous sickle cell disease (genotype HbSS) and in six normal adults (genotype HbAA) of similar age. Turnover was measured with prime/intermittent oral doses of [15N]glycine over 18 h and resting energy expenditure was measured by indirect calorimetry. In HbSS, nitrogen flux (0.9 ñ 0.08 g day-1 kg-1), protein synthesis (6.0 ñ 0.5 g day-1 kg-1) and protein degradation (5.6 ñ 0.5 g day-1 kg-1) were significantly increased compared with HbAA nitrogen (flux 0.5 ñ 0.02g day-1 kg-1, protein synthesis 3.2 ñ 0.2 g day-1 kg-1 and protein degradation 2.8 ñ 0.2 g day-1 kg-1). Resting energy expenditure was significantly higher in HbSS compared with HbAA when expressed per unit of body weight (115 ñ 3 and 94 ñ 4 kj day-1 kg-1 respectively) or weight 0.75(317 ñ 6 and 269 ñ 8 kj day-1kg-0.75, respectively). The increase in protein turnover and energy expenditure suggest that patients with HbSS exist in a hypermetabolic state that requires greater dietary energy compared with HbAA. (AU)