Table 2.
Characteristics of patients during primary SARS-CoV-2 infection correlating with post-acute COVID-19 syndrome (PACS).
| COVID-19 cases | Without PACS (n = 49) | With PACS (n = 85) | Odds ratio (CI)a | p value | |
|---|---|---|---|---|---|
| Symptom duration categories | Acute COVID-19 (<4 weeks) | Subacute COVID-19 (>4 weeks) | Post-COVID-19 syndrome (>12 weeks) | – | – |
| Symptom duration—no. | 49 | 24 | 61 | – | – |
| Severe COVID-19 cases—no. (%) | 8 (16.3) | 7 (29.2) | 30 (49.2) | 3.87 (1.67–9.89) | 0.001 |
| Demographicsb | |||||
| Age—median (IQR) | 34 (27–50) | 52 (34–65) | 1.67 (1.15–2.49) | 0.008 | |
| Sex—male no. (%) | 28 (57.1) | 47 (55.3) | 0.93 (0.45–1.89) | 0.840 | |
| Level of carec—hospitalized no. (%) | 13 (26.5) | 41 (48.2) | 2.55 (1.20–5.65) | 0.014 | |
| Days hospitalized—median (IQR) | 0 (0–1) | 1 (0–16) | 1.06 (1.02–1.12) | 0.008 | |
| No. of symptoms (IQR)d | 2 (1–3) | 3 (2–3) | 1.81 (1.31–2.58) | 0.001 | |
| Pre-existing comorbidities and treatments—no. (%) | |||||
| Hypertension | 9 (18.4) | 22 (25.9) | 1.53 (0.65–3.86) | 0.331 | |
| Diabetes mellitus | 4 (8.2) | 15 (17.6) | 2.34 (0.78–8.87) | 0.135 | |
| Cardiovascular disease | 6 (12.2) | 12 (14.1) | 1.16 (0.41–6.32) | 0.779 | |
| Lung disease | 2 (4.1) | 19 (22.4) | 6.29 (1.70–44.36) | 0.004 | |
| Asthma bronchiale | 1 (2.0) | 16 (18.8) | 9.74 (1.88–240.26) | 0.003 | |
| Kidney disease | 5 (10.2) | 10 (11.8) | 1.16 (0.38–4.02) | 0.805 | |
| History of malignancy | 2 (4.1) | 6 (7.1) | 1.70 (0.36–13.24) | 0.525 | |
| Systemic immunosuppression | 1 (2.0) | 8 (9.4) | 4.42 (0.76–113.71) | 0.109 | |
| Body-Mass-Index—median (IQR)e | 25 (22–27) | 26 (23–29) | 1.07 (0.99–1.18) | 0.116 | |
| Laboratory characteristics during primary infection—median (IQR) | |||||
| Timepoint of first sampling [days]f | 9 (6–15) | 12 (7–19) | 1.05 (1.01–1.10) | 0.022 | |
| CRP (mg/L) | 2.4 (0.6–8.8) | 11.0 (0.9–60.5) | 1.01 (1.00–1.02) | 0.022 | |
| IL-6 (pg/mL) | 2.0 (0.1–9.3) | 5.2 (0.8–20.3) | 1.01 (1.00–1.02) | 0.113 | |
| TNF (pg/mL) | 10.2 (8.2–13.0) | 11.2 (9.1–17.4) | 1.07 (1.01–1.15) | 0.049 | |
| Leukocytes (109/L) | 6.0 (5.0–7.0) | 5.8 (4.5–7.1) | 1.04 (0.95–1.16) | 0.472 | |
| Neutrophils (109/L) | 3.4 (2.6–4.5) | 3.5 (2.7–4.4) | 1.08 (0.93–1.27) | 0.340 | |
| Lymphocytes (109/L) | 1.8 (1.4–2.2) | 1.3 (0.7–2.0) | 0.96 (0.77–1.21) | 0.711 | |
| NLR | 1.7 (1.3–2.4) | 2.2 (1.6–4.3) | 1.01 (0.99–1.06) | 0.540 | |
| SARS-CoV-2 IgA (OD ratio) | 2.5 (0.9–6.1) | 3.1 (0.8–8.4) | 1.03 (0.99–1.08) | 0.218 | |
| SARS-CoV-2 IgG (OD ratio) | 0.7 (0.3–3.2) | 1.1 (0.3–6.3) | 1.08 (0.98–1.20) | 0.149 | |
| Total IgM [g/L] | 1.2 (0.9–1.6) | 0.9 (0.6–1.3) | 0.73 (0.44–1.19) | 0.204 | |
| Total IgA [g/L] | 2.2 (1.7–2.8) | 2.4 (1.9–3.1) | 1.18 (0.82–1.71) | 0.389 | |
| Total IgG [g/L] | 11.8 (10.3–13.6) | 10.9 (9.1–12.8) | 0.95 (0.85–1.06) | 0.342 | |
| Total IgG1 [g/L] | 6.1 (4.8–6.9) | 5.7 (4.3–6.8) | 0.94 (0.79–1.13) | 0.522 | |
| Total IgG2 [g/L] | 4.1 (3.0–5.2) | 3.7 (2.8–4.4) | 0.84 (0.64–1.09) | 0.186 | |
| Total IgG3 [g/L] | 0.7 (0.5–1.1) | 0.6 (0.5–1.0) | 0.71 (0.35–1.42) | 0.324 | |
| Total IgG4 [g/L] | 0.3 (0.2–0.6) | 0.3 (0.2–0.4) | 0.61 (0.24–1.52) | 0.284 | |
CI confidence interval, CRP C-reactive protein, Ig immunoglobulin, IL interleukin, IQR interquartile range, NRL neutrophil-to-lymphocyte ratio, OD optical density, PACS post-acute COVID-19 syndrome, TNF tumor necrosis factor, wks weeks.
aFor categorical variables, odds ratios compare the odds of the occurrence of PACS, given the presence of a categorical variable. For continuous variables, odds ratios were calculated using an unadjusted (univariate) logistic regression model predicting the occurrence of PACS.
bDemographics during primary infection (1st visit).
cLevel of care was prospectively followed until recovery.
dFive symptoms were systematically recorded during primary infection: fever, fatigue, cough, dyspnea, and gastrointestinal symptoms.
eMissing information on Body-Mass-Index of 23 patients.
fDays after onset of first COVID-19-related symptoms.