Abstract 4607

Introduction

The high mortality risk that sickle cell disease (SCD) patients experience from infancy is cumulative through adulthood, largely because of the effect of cumulative end organ damage, which is a more powerful predictor of early mortality than frequency of painful episodes. The latter, though, gets more attention from patients and caregivers. Any vascular territory is susceptible to damage. The most common target organs are the brain, lungs, kidneys, retina and joints. We examined the prevalence of the full spectrum of end organ damage in a cohort upon entry into our adult SCD program and compared the clinical and laboratory characteristics of patients based on age, gender and SCD type.

Patients and Methods

Retrospective review of prospectively collected data on 118 adults upon entry into our program between February 2005 and October 2008. All patients underwent a standardized battery of tests to evaluate hematological and biochemical parameters at entry. Historical presence of episodes of acute chest syndrome, pneumonia, stroke, avascular necrosis, osteomyelitis, leg ulcers, priapism, and cholecystectomy and hydroxurea therapy was quantified. Pulmonary hypertension (PHT) was defined as a tricuspid regurgitant jet velocity (TRJV) ≥2.5 m/s on Doppler echocardiography; sickle cell nephropathy (SCN) as glomerular filtration rate, (GFR) < 90ml/min. and/or 24-hour protein>300mg and/or urine protein/creatinine ratio>0.3); cerebrovascular disease (CVD) as evidence of previous ischemic and/or hemorrhagic infarct and/or aneurysm formation on brain MRI/MR angiography; and sickle cell retinopathy (SCR) as background to proliferative retinopathy) on fluorescent retinal angiography. Characteristics of patients were evaluated with t-test for continuous variables and chi-square test for the categorical variables.

Results

The relevant statistically significant correlative variables in these 3 comparisons are shown in the following tables.

Table 1.

Age comparison:

NAge (years)
p-value
<20 (n=62)20 to<30 (n=22)30 to <40 (n=18)≥40 (n=16)
Clinical and Laboratory Features 
Avascular necrosis % 118 8.06 4.55 16.67 37.5 0.0087* 
Leg ulcers % 118 1.61 4.55 27.78 37.5 <.0001* 
Bilirubin (mean) 116 3.05 ±2.27 2.79 ±2.2 2.28 ±1.51 1.7 ±1.97 0.0317* 
End Organ Damage 
SCR % 68 20.51 42.86 53.85 88.89 0.001* 
SCN % 92 36 57.14 71.43 85.71 0.0032* 
NAge (years)
p-value
<20 (n=62)20 to<30 (n=22)30 to <40 (n=18)≥40 (n=16)
Clinical and Laboratory Features 
Avascular necrosis % 118 8.06 4.55 16.67 37.5 0.0087* 
Leg ulcers % 118 1.61 4.55 27.78 37.5 <.0001* 
Bilirubin (mean) 116 3.05 ±2.27 2.79 ±2.2 2.28 ±1.51 1.7 ±1.97 0.0317* 
End Organ Damage 
SCR % 68 20.51 42.86 53.85 88.89 0.001* 
SCN % 92 36 57.14 71.43 85.71 0.0032* 
Table 2.

Gender Comparison

NFemales (n=58)Males (n=60)p-value
Clinical and Laboratory Features 
Hydroxyurea therapy % 118 12.07 36.67 0.0019* 
Hemoglobin (mean) 117 9.13±1.74 10.4±2.33 0.0011* 
Urine protein/Cr ratio (mean) 91 0.51±0.75 0.23±0.32 0.0199* 
24 hour urine protein (mean) 84 489.39±634.93 231.14±241.62 0.019* 
NFemales (n=58)Males (n=60)p-value
Clinical and Laboratory Features 
Hydroxyurea therapy % 118 12.07 36.67 0.0019* 
Hemoglobin (mean) 117 9.13±1.74 10.4±2.33 0.0011* 
Urine protein/Cr ratio (mean) 91 0.51±0.75 0.23±0.32 0.0199* 
24 hour urine protein (mean) 84 489.39±634.93 231.14±241.62 0.019* 
Table 3.

Comparison between SCD types

NSC (n=27)SS/Sβ0 (n=74)p-value
Clinical and Laboratory Features 
Age (mean) 101 32.76±14.93 24.42±9.37 0.0104* 
Pneumonia (mean no. of episodes) 101 0.44±1.22 1.57±1.97 0.0006* 
Priapism % 55 5.88 28.95 0.0796 
Cholecystectomy % 101 7.41 47.3 0.0002* 
Hydroxyurea therapy % 101 3.7 33.78 0.0022* 
Hemoglobin (mean) 101 11.99±1.63 8.67±1.49 <.0001* 
MCV (mean) 101 84.53±11.07 92.74±13.89 0.0068* 
Reticulocyte count, absolute (mean) 62 186.46±64.57 279.57±98.67 0.0015* 
Reticulocyte, percentage (mean) 86 4.72±2.1 9.58±4.66 <.0001* 
Platelet count (mean) 101 283.41±127.06 434.7±157.9 <.0001* 
Bilirubin (mean) 101 1.3±0.8 3.47±2.24 <.0001* 
Ferritin (mean) 99 229.51±217.68 902.36±1321.9 <.0001* 
Creatinine (mean) 101 0.89±0.89 0.71±0.35 0.0231* 
GFR (mean) 75 86.3±36.12 117.34±51.31 0.0152* 
End Organ Damage     
Retinopathy % 62 61.54 (8/13) 32.65 (16/49) 0.0573 
NSC (n=27)SS/Sβ0 (n=74)p-value
Clinical and Laboratory Features 
Age (mean) 101 32.76±14.93 24.42±9.37 0.0104* 
Pneumonia (mean no. of episodes) 101 0.44±1.22 1.57±1.97 0.0006* 
Priapism % 55 5.88 28.95 0.0796 
Cholecystectomy % 101 7.41 47.3 0.0002* 
Hydroxyurea therapy % 101 3.7 33.78 0.0022* 
Hemoglobin (mean) 101 11.99±1.63 8.67±1.49 <.0001* 
MCV (mean) 101 84.53±11.07 92.74±13.89 0.0068* 
Reticulocyte count, absolute (mean) 62 186.46±64.57 279.57±98.67 0.0015* 
Reticulocyte, percentage (mean) 86 4.72±2.1 9.58±4.66 <.0001* 
Platelet count (mean) 101 283.41±127.06 434.7±157.9 <.0001* 
Bilirubin (mean) 101 1.3±0.8 3.47±2.24 <.0001* 
Ferritin (mean) 99 229.51±217.68 902.36±1321.9 <.0001* 
Creatinine (mean) 101 0.89±0.89 0.71±0.35 0.0231* 
GFR (mean) 75 86.3±36.12 117.34±51.31 0.0152* 
End Organ Damage     
Retinopathy % 62 61.54 (8/13) 32.65 (16/49) 0.0573 

N, number of patients tested or values reported; MCV, mean corpuscular volume

*

Statistically significant at significance level 0.05

Excludes 17 patients with Sβ+/SHPFH/other, not included in the comparison because of the small numbers.

Conclusions

Our study highlights the various differences in the prevalence of sickle cell disease-related end organ damage and morbidity among different age, gender and two major sickle cell disease categories. It shows the significant progression of organ damage with advancing age and the more severe nature of SS/Sβ0 phenotype. Further expansion of this assessment may help identify specific high risk groups that can be targeted as candidates for more intensive preventive interventions.

Disclosures:

No relevant conflicts of interest to declare.

Author notes

*

Asterisk with author names denotes non-ASH members.

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