Table 2.
Clinical laboratory values in children with severe anemia and P falciparum parasitemia by sickle cell genotype
| HbSS, n = 22 | HbAA, n = 208 | P*,† | β coefficient‡,§ (95% CI) |
P,† adjusted for age |
|
|---|---|---|---|---|---|
| Complete blood count (mean ± SD) | |||||
| Hemoglobin, g/dL | 3.7 (0.6) | 3.7 (0.9) (n = 208) | .71 | −0.04 (−0.4, 0.4) | .85 |
| Hematocrit, % | 12.5 (2.5) | 13.7 (5.8) (n = 206) | .35 | −1.7 (−4.2, 0.9) | .21 |
| MCV, fL | 96.9 (11.7) | 82.4 (10.3) (n = 206) | <.001 | 14.4 (9.5, 19.2) | <.001 |
| RDW, % | 21.4 (5.17) | 16.4 (3.7) (n = 202) | <.001 | 6.2 (4.4, 7.9) | <.001 |
| WBC count, ×103/μL | 32.5 (16.0) (n = 21) | 12.9 (8.2) (n = 206) | <.001 | 20.1 (15.8, 24.5) | <.001 |
| % Neutrophils | 40.5 (12.8) (n = 20) | 46.8 (13.7) (n = 206) | .05 | −9.2 (−15.5, −2.8) | .005 |
| % Lymphocytes | 48.7 (15.1) (n = 20) | 41.0 (12.4) (n = 206) | .01 | 10.2 (4.2, 16.1) | .001 |
| % Monocytes | 8.7 (4.0) (n = 20) | 10.4 (5.5) (n = 206) | .16 | −1.3 (−3.9, 1.3) | .32 |
| % Basophils | 1.7 (1.4) (n = 14) | 1.2 (1.3) (n = 161) | .14 | 0.5 (−0.2, 1.2) | .18 |
| % Eosinophils | 1.3 (2.1) (n = 14) | 1.1 (1.1) (n = 161) | .48 | 0.3 (−0.4, 1.0) | .39 |
| Platelet count, x103/μL | 273 (203) | 175 (126) (n = 206) | .002 | 86.7 (24.1, 149.4) | .007 |
| Plasma markers of hemolysis (median, IQR) | |||||
| LDH, U/L | 639 (469, 769) (n = 21) | 772 (639, 995) (n = 194) | .02 | −0.1 (−0.2, −0.004)§ | .04 |
| Haptoglobin, mg/dL | 0.1 (0.1, 0.1) (n = 21) | 0.1 (0.1, 0.1) (n = 195) | .64 | 0.2 (−0.2, 0.4)§ | .52 |
| Total bilirubin, mg/dL | 2.7 (1.6, 5) (n = 21) | 1.2 (0.7, 1.9) (n = 195) | <.001 | 0.3 (0.2, 0.5)§ | <.001 |
| Renal function (median, IQR) | |||||
| Creatinine, mg/dL | 0.35 (0.27, 0.43) (n = 21) | 0.35 (0.28, 0.47) (n = 196) | .73 | −0.08 (−0.16, −0.004)§ | .04 |
| BUN, mg/dL | 9.0 (7.0, 13) | 14 (9.0, 20) (n = 204) | .007 | −0.2 (−0.3, −0.1)§ | .001 |
| Other clinical laboratory values (median, IQR) | |||||
| Albumin, g/dL | 3.3 (2.9, 3.5) | 2.6 (2.3, 2.9) (n = 203) | <.001 | 0.09 (0.05, 0.12)§ | <.001 |
| Lactate, mmol/L | 3.9 (2.2, 7.0) (n = 20) | 5.0 (3.0, 8.3) (n = 194) | .21 | −0.7 (−2.5, 1.0) | .43 |
| Blood culture positivity, n (%) | 1 (5.5) (n = 18) | 22 (12.4) (n = 178) | .64 | −0.03 (−0.2, 0.1) | .75 |
| Stool helminthic infection, n (%) | 0 (0) (n = 160 | 9 (6.8) (n = 132) | .60 | −0.08 (−0.2, 0.05) | .22 |
| HIV positivity, n (%) | 0 (0) (n = 22) | 6 (2.9) (n = 205) | 1.0 | −0.04 (−0.1, 0.04) | .33 |
| Parasite density and PfHRP-2 concentration (median, IQR) | |||||
| P falciparum HRP-2, ng/mL | 197 (6, 469) | 1050 (468, 2840) (n = 205) | <.001 | −1.0§ (−1.3, −0.6)§ | <.001 |
| Parasite density in peripheral blood, parasites ×103/μL | 42 (3.0, 141) (n = 21) | 50 (15, 230) (n = 205) | .18 | −0.3 (−0.7, 0.2)§ | .29 |
| Estimated parasite biomass | |||||
| Circulating (×109) | 60 (3.00, 189) (n = 21) | 51 (14, 207) (n = 205) | .42 | −0.3 (−0.7, 0.2) | .31 |
| Sequestered (×109) | 130 (0.00, 325) (n = 21) | 731 (190, 1921) (n = 202) | <.001 | −0.5 (−0.9, −0.1) | .01 |
| Total (×109) | 238 (6.00, 445) | 835 (327, 2043) (n = 203) | <.001 | −0.6 (−0.9, −0.3) | <.001 |
For tests that did not include all participants, the n is listed next to the result.
HRP-2, histidine-rich protein-2; IQR, interquartile range.
*
Determined by use of χ2 or Fisher exact test for categorical data where appropriate, Student t test for parametric continuous data, and Wilcoxon rank-sum test for nonparametric continuous data, as appropriate.
†
Significance determined with FDR = 0.05 correction for multiple comparisons. Bold P values represent significant differences.
‡
β coefficient of linear regression controlling for age.
§
Log10-transformed values used for linear regression.