Article Figures & Data
Figures
- Figure 1. Percentage of children with sickle cell disease who had any of the listed health problems as a function of plasma retinol concentration below normal (<20 μg/dL) and within the normal range (≥20 μg/dL). A higher percentage of children with plasma retinol <20 μg/dL vs children with levels ≥20 μg/dL had pain crisis episodes (chi-square test, a>b, P < 0.05) or inflammation (*P = 0.1). For all other measurements, no significant differences were detected.
- Figure 2. Lymphocyte proliferative responses of peripheral blood mononuclear cells to phytohemagglutinin (PHA) (A) as a function of plasma retinol concentration (n = 7 VAD and n = 52 VAA children); (B) in boys with HbSS and VAD (n = 5) and boys with HbSS and VAA (n = 18); (C) in children with retinol binding protein (RBP) and plasma retinol below normal (n = 6) and children with normal plasma retinol but RBP below normal (n = 31); and (D) as a function of health scores (n = 29, n = 20, and n = 8 for health scores 0-2, 3-8, and >8, respectively). For 2A, 2B, and 2C, no significant differences in mean stimulation indexes (SI) were found between children with plasma retinol levels <20 μg/dL and those with levels ≥20 μg/dL. For 2D, for each PHA concentration (2.5, 5, 10, or 15 μg/mL), a dose-dependent decrease in the rate of DNA synthesis was seen with increased health scores (P < 0.05 to P = 0.1). Values are mean ± SEM. CPM, counts per minute; VAA, vitamin A–adequate, VAD, vitamin A–deficient.
- Figure 3. Interleukin-2 (IL-2) concentrations in phytohemagglutinin (PHA)-treated and untreated peripheral blood mononuclear cells in children with sickle cell disease (A) as a function of plasma retinol levels (n = 52 children with normal plasma retinol levels and n = 7 children with deficient plasma retinol levels); (B) in boys with HbSS and plasma retinol below normal (n = 5) and boys with normal plasma retinol (n = 18); (C) in children with retinol binding protein (RBP) and plasma retinol below normal (n = 6) and children with normal plasma retinol but RBP below normal (n = 31); and (D) as a function of health scores (n = 29, n = 20, and n = 8 for health scores 0-2, 3-8, and >8, respectively). For 3A and 3C (PHA 0 μg/mL), the mean IL-2 concentrations of children with plasma retinol <20 μg/dL were higher than those with plasma retinol ≥20 mg/dL (a>b, P < 0.05 in 3A; †P = 0.052 in 3C). For PHA 5 and/or 15 μg/mL, the mean IL-2 concentrations of children with plasma retinol <20 μg/dL were lower than those of children with plasma retinol ≥20 μg/dL (*P < 0.1 but >0.05 in 3C). The means of IL-2 activity between children plasma retinol <20 μg/dL and those with levels ≥20 μg/dL (3B) and as a function of health scores (3D) were not statistically different. Values are mean ± SEM. VAA, vitamin A–adequate, VAD, vitamin A–deficient.
Tables
Hemoglobin Genotype HbSS HbSC HbSβthal Total Mean Age, years, ± SEM Boys 23 7 4 34 7.63 ± 0.71 Girls 17 4 4 25 7.63 ± 1.00 Total 40 11 8 59 7.63 ± 0.59 Mean age, years, ± SEM 8.20 ± 0.66b 5.03 ± 1.24a 8.34 ± 2.02b 7.63 ± 0.59 Note: Two boys and one girl had HbSβ0 genotype. The mean ± SEM ages in years of children with HbSβ0 (n = 3) and HbSβ+ (n = 5) were 9.17 ± 2.41 and 7.85 ± 5.43, respectively (and were not significantly different). Children with HbSC genotype were younger than those with HbSS or HbSβthal (a<b; P < 0.05).
Group n Mean (± SEM) Plasma Retinol Level, μg/dL Plasma Retinol Range, μg/dL Children with HbSS 40 57.1 ± 4.7 6-116 Children with HbSC 11 60.9 ± 5.7 39-87 Children with HbSβthal 8 55.5 ± 12.8 4.6-109 Children in the control group 14 59.0 ± 5.88 28.7-119 Laboratory employees 7 70.0 ± 17.39 43.0-162 All patients 59 57.6 ± 3.7 4.6-116 All controls 21 62 ± 6.5 28.7-162 Note: No significant differences were observed between patients and the combined controls and/or by hemoglobin genotype.
- Table 3. Mean (± SEM) Age and Clinical Status of Children With Sickle Cell Disease as a Function of Plasma Retinol Concentration
Variable Plasma Retinol <20 μg/dL (n = 7)a Plasma Retinol ≥20 μg/dL (n = 52)a P Value Plasma Retinol <20 μg/dL (n = 5 boys with HbSS) Plasma Retinol ≥20 μg/dL (n = 18 boys with HbSS) P Value Age, years 8.81 ± 1.1 7.47 ± 0.65 8.87 ± 1.51 7.22 ± 0.80 Weight, kg 26.83 ± 2.82 25.54 ± 2.33 25.38 ± 3.35 22.53 ± 2.25 Weight percentile 28.21 ± 10.77 37.72 ± 4.62 20.50 ± 9.25 23.06 ± 5.89 Height, cm 131.5 ± 6.22 119.26 ± 4.45 128.8 ± 7.52 118.64 ± 6.99 Height percentile 22.5 ± 5.82 40.28 ± 4.87 0.09 25.07 ± 6.61 26.31 ± 7.46 Pain crises 1.57 ± 0.43 0.72 ± 0.19 0.05 1.40 ± 0.51 0.82 ± 0.23 Units of blood 0.71 ± 0.71 1.17 ± 0.33 1.00 ± 0.998 1.35 ± 0.64 Infections 0.57 ± 0.297 0.58 ± 0.13 0.60 ± 0.399 0.81 ± 0.28 Hospitalizations 1.86 ± 0.96 1.43 ± 0.27 1.20 ± 0.582 2.07 ± 0.59 Hematocrit, % 26.5 ± 1.87 27.78 ± 0.69 25.10 ± 2.28 24.22 ± 0.78 Hemoglobin, g/dL 8.50 ± 0.54 8.79 ± 0.2 8.22 ± 0.64 7.74 ± 0.18 White blood cells × 106/mL 12.10 ± 0.97 12.69 ± 0.75 11.57 ± 1.11 14.57 ± 1.26 C-reactive protein, mg/L 18.27 ± 12.8 5.50 ± 1.64 0.05 25.58 ± 17.23 8.38 ± 4.24 0.08 Alpha-1-acid glycoprotein, g/L 071 ± 0.19 0.69 ± 0.04 0.83 ± 0.22 0.66 ± 0.08 Retinol binding protein, mg/L 19.30 ± 4.06 21.56 ± 1.14 14.72 ± 2.76 19.22 ± 1.81 Tumor necrosis factor-α, pg/mL 32.71 ± 19.7 50.61 ± 13.64 33.74 ± 28.05 69.73 ± 28.62 Inflammation score 0.71 ± 0.29 0.35 ± 0.08 0.07 0.80 ± 0.37 0.33 ± 0.16 0.1 Health scoreb 5.43 ± 1.67 3.84 ± 0.61 5.20 ± 1.83 4.83 ± 1.09 - Table 4. Mean (± SEM) Age and Clinical Status of Boys and Girls With Sickle Cell Disease Independent of Vitamin A Status
Variable Boys (n = 34) Girls (n = 25) Age, years 6.62 ± 0.71 7.63 ± 1.01 Plasma retinol, μg/dL 49.8 ± 4.90 68.1 ± 5.1a Weight, kg 25.78 ± 2.65 25.64 ± 3.26 Weight percentile 34.05 ± 5.59 39.7 ± 6.60 Height, cm 121.32 ± 4.76 119.86 ± 7.27 Height percentile 35.76 ± 5.95 41.66 ± 6.65 Pain crises 0.72 ± 0.16 1.00 ± 0.38 Units of blood 0.91 ± 0.37 1.41 ± 0.49 Infections 0.66 ± 0.16 0.50 ± 0.18 Hospitalizations 1.43 ± 0.33 1.57 ± 0.47 Hematocrit, % 26.98 ± 0.93 28.48 ± 0.87 Hemoglobin, g/dL 8.58 ± 0.32 9.00 ± 0.36 White blood cells × 106/mL 13.30 ± 0.84 11.72 ± 1.06 C-reactive protein, mg/L 8.85 ± 0.39 4.444 ± 1.2 Alpha-1-acid glycoprotein, g/L 0.689 ± 0.06 0.689 ± 0.05 Retinol binding protein, mg/L 21.02 ± 1.52 21.63 ± 1.64 Tumor necrosis factor alpha, pg/mL 59.4 ± 17.89 32.55 ± 14.04 Inflammation score 0.412 ± 0.12 0.36 ± 0.098 Health scoreb 3.82 ± 0.65 4.35 ± 1.05 - Table 5. Mean (± SEM) Age and Clinical Status of Children with Sickle Cell Disease as a Function of Inflammation
Variable Without Inflammation (n = 40) With Inflammationa (n = 19) Age, years 8.354 ± 0.753 6.09 ± 0.811b Plasma retinol, μg/dL 60.9 ± 7.0 50.90 ± 4.3c Weight, kg 28.39 ± 2.58 18.864 ± 2.21 Weight percentile 38.08 ± 5.16 32.393 ± 7.63 Height, cm 125.64 ± 4.60 107.23 ± 7.14 Height percentile 39.54 ± 5.24 34.64 ± 8.42 Pain crises 0.892 ± 0.31 0.688 ± 0.24 Units of blood 1.333 ± 0.398 0.563 ± 0.33 Infections 0.526 ± 0.15 0.688 ± 0.18 Hospitalizations 1.60 ± 0.35 1.25 ± 0.43 Hematocrit, % 27.45 ± 0.81 28.00 ± 1.08 Hemoglobin, g/dL 8.81 ± 0.31 8.673 ± 0.39 White blood cells × 106/mL 12.364 ± 0.79 13.15 ± 1.23 Health scored 4.154 ± 0.77 3.78 ± 0.72 - Table 6. Correlation Coefficients (r) Between Indicators of Clinical Status and Lymphocyte Proliferative Responses to Phytohemagglutinin (PHA) (corrected for baseline 3H-thymidine uptake) in Children With Sickle Cell Disease
Variable PHA 2.5 μg/mL PHA 5 μg/mL PHA 10 μg/mL PHA 15 μg/mL Retinol binding protein 0.242a 0.307a 0.349a 0.367a Health scoreb −0.319a −0.272a −0.287a −0.326a Pain crises −0.252a −0.182 −0.195 −0.195 Units of blood −0.195 −0.243a −0.266a −0322a Infections −0.151 −0.138 −0.172 −0.042
