Mean Values of Red Blood Cell Variables That Affect Polymerization and Clinical Severity for a Cohort of Adult Sickle Cell Anemia Patients
| . | Hct (%) . | Hb (g/dL) . | MCHC (g/dL) . | ATP (mmol/L) . | 2,3-DPG (mmol/L) . | Hb F-150 (%) . | Hb A2 (%) . | fp-151 . | Hosp. (d/yr) . | CSS-152 . |
|---|---|---|---|---|---|---|---|---|---|---|
| Mean | 26.1 ± 4.3 | 8.7 ± 1.3 | 33.7 ± 1.5 | 1.4 ± 0.2 | 6.1 ± 0.8 | 5.5 ± 4.4 | 3.0 ± 0.6 | 0.49 ± 0.07 | 21.8 ± 27.8 | 0.83 ± 0.71 |
| No. | 46 | 46 | 46 | 43 | 46 | 46 | 44 | 46 | 46 | 46 |
| Range | 18.0-39.6 | 6.4-12.7 | 30.5-36.3 | 1.1-1.9 | 4.3-9.5 | 0.8-16.2 | 1.5-3.9 | 0.30-0.59 | 0-140 | 0-3 |
| . | Hct (%) . | Hb (g/dL) . | MCHC (g/dL) . | ATP (mmol/L) . | 2,3-DPG (mmol/L) . | Hb F-150 (%) . | Hb A2 (%) . | fp-151 . | Hosp. (d/yr) . | CSS-152 . |
|---|---|---|---|---|---|---|---|---|---|---|
| Mean | 26.1 ± 4.3 | 8.7 ± 1.3 | 33.7 ± 1.5 | 1.4 ± 0.2 | 6.1 ± 0.8 | 5.5 ± 4.4 | 3.0 ± 0.6 | 0.49 ± 0.07 | 21.8 ± 27.8 | 0.83 ± 0.71 |
| No. | 46 | 46 | 46 | 43 | 46 | 46 | 44 | 46 | 46 | 46 |
| Range | 18.0-39.6 | 6.4-12.7 | 30.5-36.3 | 1.1-1.9 | 4.3-9.5 | 0.8-16.2 | 1.5-3.9 | 0.30-0.59 | 0-140 | 0-3 |
For the 12 patients evaluated more than once (one, 4 times; two, 3 times; nine, twice), mean values were used here.
Seven of the 46 blood samples used for this study had Hb F levels >10%. The possibility that these patients may be double heterozygotes (S/HPFH or S/δβ-thal) rather than SS homozygotes has not been ruled out.
Polymer fraction at the nominal O2 tension of the microvasculature (pO2 = 20 mm Hg, corresponding to 25% O2 saturation); calculated from the conservation of mass relationship: fp = cp(ct − csat)/ct(cp − csat) where cp, ct, and csat are the polymer concentration (69.3 g/dL), the total hemoglobin concentration (MCHC), and the equilibrium solubility at 25% O2 saturation, respectively.
Clinical severity score based on average frequency of hospitalizations for pain crises per year: 0 points for none or less than one; 1 point for 1-5 crises per year; 2 points for 6-10; 3 points for more than 10.