Table 1.
Patients’ Characteristics and Baseline Laboratory Parameters
| Characteristics | Category | Overall (n = 904) |
With Secondary Infections (n = 109) |
Without Secondary Infections (n = 795) |
P Valuea |
|---|---|---|---|---|---|
| Age, y | … | 64 (55–76) | 63 (56–71) | 65 (54–76) | .902 |
| Sex, female | … | 297 (32.9%) | 22 (20.2%) | 275 (34.6%) | .002 |
| Arterial hypertension | … | 400 (45.4%) | 38 (39.6%) | 362 (46.1%) | .234 |
| Coronary artery disease | … | 226 (25.7%) | 20 (20.8%) | 206 (26.2%) | .268 |
| Diabetes mellitus | … | 158 (17.9%) | 21 (21.6%) | 137 (17.5%) | .326 |
| Chronic obstructive pulmonary disease | … | 64 (7.3%) | 3 (3.1%) | 61 (7.8%) | .100 |
| Chronic kidney disease | … | 87 (9.9%) | 8 (8.2%) | 79 (10.1%) | .718 |
| Malignancy | … | 133 (15.1%) | 7 (7.3%) | 126 (16.1%) | .022 |
| Liver disease | … | 17 (2.9%) | 3 (6.5%) | 14 (2.6%) | .143 |
| No. of comorbidities | … | 1 (0–2) | 1 (0–2) | 1 (0–2) | .122 |
| Days from symptom onset to hospital admission | … | 7 (3–10) | 7 (3–9) | 7 (3–10) | .503 |
| ICU admission | … | 123 (13.6%) | 75 (68.8%) | 48 (6%) | <.0001 |
| ICU admission within 48 h of hospital admission | … | 61 (6.7%) | 29 (26.6%) | 32 (4%) | <.0001 |
| PaO2/FiO2 | … | 224 (100–305) | 109 (100–229) | 238 (100–311) | <.0001 |
| >200 | 384 (42.5%) | 29 (26.6%) | 355 (44.7%) | <.0001 | |
| <200 | 311 (34.4%) | 63 (57.8%) | 248 (31.2%) | ||
| Unknown | 209 (23.1%) | 17 (15.6%) | 192 (24.2%) | ||
| Use of biological immunosuppressive drugs | … | 149 (16.5%) | 26 (23.9%) | 123 (15.5%) | .038 |
| Use of corticosteroids (available in n = 599) | … | 139 (23.2%) | 13 (21.3%) | 126 (23.4%) | .873 |
| Use of remdesivir | … | 32 (3.5%) | 2 (1.8%) | 30 (3.8%) | .414 |
| Use of heparin (available in n = 599) | … | 308 (51.4%) | 25 (40.9%)b | 283 (52.6%) | .085 |
| Hemoglobin, g/dL | … | 13.5 (12–14.7) | 13.8 (12–15) | 13.4 (12–14.6) | .300 |
| Platelets, per 109/L | … | 207 (155–272) | 220 (147–316) | 206 (156–269) | .331 |
| White blood cells, per 109/L | … | 6.9 (5–9.9) | 7.8 (5.4–12) | 6.8 (4.9–9.7) | .003 |
| Neutrophils, per 109/L | … | 4.9 (3.4–7.7) | 6 (4–9.7) | 4.9 (3.3–7.4) | .001 |
| Lymphocytes, per 109/L | … | 1 (0.7–1.3) | 0.8 (0.6–1.1) | 1 (0.7–1.4) | .017 |
| Creatinine, mg/dL | … | 0.98 (0.8–1.23) | 0.99 (0.85–1.28) | 0.97 (0.79–1.23) | .301 |
| ALT, U/L | … | 35 (23–56) | 41 (26–68) | 34 (22–55) | .010 |
| AST, U/L | … | 44 (31–66) | 49 (35–87) | 44 (30–63) | .003 |
| LDH, U/L | … | 363 (274–468) | 431 (339–597) | 355 (268–456) | <.0001 |
| Ferritin (available in n = 54), ng/mL | … | 926 (480–1684) | 1524 (1002–3097) | 888.5 (474–1499.5) | .134 |
| CRP, mg/L | … | 70.9 (29.1–132.5) | 117.2 (48.9–211.8) | 67.75 (26.9–123.7) | <.0001 |
| D-dimer (available in n = 204), μg/mL | … | 0.98 (0.53–2.46) | 1.32 (0.99–3.15) | 0.9 (0.5–2.37) | .010 |
| Prothrombin time, sec | … | 13.9 (13.1–15.3) | 14.2 (13.3–15.6) | 13.8 (13.1–15.3) | .265 |
| Cytolysis score | … | … | … | … | <.0001 |
| 0 | 527 (59.6%) | 54 (50.5%) | 473 (60.9%) | ||
| 1 | 157 (17.8%) | 14 (13.1%) | 143 (18.4%) | ||
| 2 | 127 (14.4%) | 15 (14%) | 112 (14.4%) | ||
| 3 | 73 (8.3%) | 24 (22.4%) | 49 (6.3%) | ||
| Inflammation score | … | … | … | … | <.0001 |
| 0 | 665 (75.5%) | 56 (53.3%) | 609 (78.5%) | ||
| 1 | 214 (24.3%) | 48 (45.7%) | 166 (21.4%) | ||
| 2 | 2 (0.2%) | 1 (1%) | 1 (0.1%) | ||
| Coagulation score | … | … | … | … | .191 |
| 0 | 554 (70.8%) | 68 (65.4%) | 486 (71.6%) | ||
| 1 | 209 (26.7%) | 31 (29.8%) | 178 (26.2%) | ||
| 2 | 20 (2.6%) | 5 (4.8%) | 15 (2.2%) |
Results are reported as median (IQR) or frequency (%). P-value < .05 are reported in bold. For variables with >10% missing values, actual numbers of observations are reported. Cytolysis score included alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase. Inflammation score included ferritin and C-reactive protein. Coagulation score included D-dimer and prothrombin time. The 3 scores had a range of 0–2 or –3, with 0 corresponding to no abnormalities in inflammatory parameter levels and 2 or 3 corresponding to patients with markedly elevated values for all the considered laboratory parameters.
Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; CRP, C-reactive protein; ICU, intensive care unit; IQR, interquartile range; LDH, lactate dehydrogenase; PaO2/FiO2, partial pressure of oxygen in the arterial blood/fraction of inspired oxygen.
By chi-square or Fisher's exact test (categorical variables) or Wilcoxon rank-sum test (continuous variables).
Twenty-four of 25 patients with secondary infections received heparin before the diagnosis of the infectious complication.