Table 1. Characteristics of patients with normal (Group A) and abnormal (Group B) 6MWT; results represent median (range) unless otherwise indicated.
| WHOLE COHORT | UNTRANSFUSED PATIENTS | |||||
| Group A | Group B | p value | Group A | Group B | p value | |
| Number of patients | 32 | 14 | 26 | 11 | ||
| Age, years | 13 (6.1–19.7) | 11.5 (8.5–18.0) | 0.29 | 13 (6.1–19.7) | 10.4 (8.5–18.0) | 0.38 |
| Male gender, n (%) | 15 (46.9%) | 5 (35.7%) | 0.48 | 9 (34.6%) | 4 (36.4%) | 1.00 |
| BMI (kg/m2) | 18.5 (12.7–26.0) | 19.6 (14.9–28.9) | 0.19 | 19.8 (14.9–28.9) | 18.1 (12.7–26.0) | 0.25 |
| African central origin, n (%) | 24 (75.0%) | 8 (57.1%) | 0.23 | 20 (76.9%) | 6 (54.6%) | 0.24 |
| HbSS/Sβ0, n (%) | 31 (96.6%) | 12 (85.7%) | 0.16 | 25 (96.2%) | 9 (81.8%) | 0.21 |
| G6PD deficiency* | 3 (9.7%) | 1 (7.7%) | 0.83 | 2 (7.7%) | 0 | 1.00 |
| Number of VOC | 1 (1–10) | 0 (0–9) | 0.58 | 1 (0–10) | 0 (0–9) | 0.92 |
| History of ≥2 ACS, n (%) | 20 (64.5%) | 6 (42.9%) | 0.17 | 14 (53.9%) | 4 (36.4%) | 0.48 |
| Dactylitis, n (%) | 7 (35.0%) | 3 (21.4%) | 0.78 | 6 (23.1%) | 2 (18.2%) | 1.00 |
| Splenic sequestration, n (%) | 10 (31.3%) | 3 (21.4%) | 0.50 | 8 (30.8%) | 2 (18.2%) | 0.69 |
| Osteonecrosis femoral head/hip, n (%) | 4 (12.5%) | 2 (14.3%) | 0.87 | 3 (11.5%) | 2 (18.2%) | 0.62 |
| Overt Stroke, n (%) | 0 | 1 (7.1%) | 0.13 | 0 | 0 | NA |
| Silent infarct, n (%) | 6 (19.4%) | 6 (42.9%) | 0.09 | 1 (3.9%) | 4 (36.4%) | 0.02 |
| Severe Infections, n (%) | 8 (25.0%) | 2 (14.3%) | 0.39 | 7 (26.9%) | 1 (9.1%) | 0.39 |
| Hydroxyurea treatment, n (%) | 30 (93.7%)** | 12 (85.7%)** | 0.37 | 25 (96.2%) | 10 (90.9%) | 0.51 |
| Chronic tranfusion program, n (%) | 6 (18.8%) | 3 (21.4%) | 0.83 | 0 | 0 | NA |
| Transcranial doppler velocity <170 cm/s, n (%) | 30 (96.8%) | 11 (84.6%) | 0.14 | 25 (96.2%) | 10 (90.9%) | 0.51 |
| FEV1/VC (%) | 88 (73–134) | 95 (78–123) | 0.79 | 93 (73–134) | 92 (78–123) | 1.00 |
| TLC (% PV) | 81 (56–104) | 80 (66–114) | 0.86 | 81 (58–104) | 77 (66–89) | 0.62 |
| SaO2 before 6MWT, (%) | 100 (96–100) | 98 (97–100) | 0.02 | 100 (96–100) | 99 (97–100) | 0.046 |
| SaO2 ≤98% after 6MWT, n (%) | 7 (22.0%) | 4 (28.6%)* | 0.72 | 6 (23.1%) | 4 (36.4%)* | 0.44 |
| Haemoglobin (g/dl) | 9.0 (6.7–12.2) | 9.1 (7.6–10.5) | 0.99 | 8.8 (6.7–12.2) | 9 (7.6–10.5) | 0.93 |
| MCV (fL) | 90.4 (64.0–111.7) | 92.2 (75.5–115.0) | 0.99 | 94.7 (64.0–111.7) | 92.3 (81.0–115.0) | 0.82 |
| Hemoglobin fœtal (% Hb total) | 13.4 (0.2–27.8) | 13.7 (1–18) | 0.71 | 14.8 (4.1–27.8) | 14.5 (1.8–18.0) | 0.53 |
| Platelets (103/µL) | 441 (153–618) | 457 (197–1036) | 0.42 | 431 (153–618) | 389 (197–1036) | 0.99 |
| Reticulocytes (103/µL) | 341 (120–491) | 277 (155–511) | 0.30 | 318 (120–466) | 273 (155–511) | 0.54 |
| Polynuclear Neutrophils (103/µL) | 4.4 (2.0–7.9) | 4.4 (1.4–8.4) | 0.84 | 4.1 (2.0–5.5) | 4.2 (1.4–5.7) | 0.64 |
| LDH (UI/L) | 830 (382–1394) | 936 (405–1399) | 0.68 | 831 (382–1394) | 927 (406–1400) | 0.56 |
* Missing data for 2 patients.
** In combination with chronic transfusion in 6 patients in group A and in 3 patients in group B.
BMI, Body Mass Index; G6PD, Glucose 6 Phosphate Dehydrogenase; VOC, Vaso-Occulsive Crisis having required an hospitalisation during the last 4 years; ACS, Acute Chest Syndrome; Severe infections: septicemia, osteomyelitis, meningitis; FEV, Forced Expiratory Volume in 1 second; VC, Vital Capacity; TLC, Total Lung Capacity; % PV, Per Cent of the predicted value; 6MWT, 6-Minute Walk Test; MCV, Mean Cell Volume; LDH, Lactate Dehyrogenase.