Table 2.
Characteristics of 121 patients with ARF associated with Svv on ICU admission
| All patients n = 121 | Immune ARF n = 67 | Non-immune ARF n = 54 | p | ||||
|---|---|---|---|---|---|---|---|
| Demographics | |||||||
| Age, year | 62 | [50–75] | 59 | [44–72] | 68 | [57–76] | 0.008 |
| Male gender, n (%) | 75 | (62) | 38 | (57) | 37 | (69) | 0.184 |
| Diabetes | 34 | (28) | 16 | (24) | 18 | (33) | 0.250 |
| Cardiovascular diseasea, n (%) | 63 | (52) | 27 | (40) | 36 | (67) | 0.004 |
| Respiratory diseaseb, n (%) | 36 | (30) | 14 | (21) | 22 | (41) | 0.002 |
| Immunosuppressionc, n (%) | 55 | (45) | 10 | (15) | 45 | (83) | < 0.0001 |
| Severe chronic renal failured, n (%) | 23 | (19) | 4 | (6) | 19 | (35) | < 0.0001 |
| Small vessel vasculitis [Svv] | |||||||
| Etiology of Svv | 0.358 | ||||||
| GPA | 52 | (43) | 28 | (42) | 24 | (44) | |
| MPA | 37 | (31) | 24 | (36) | 13 | (24) | |
| EGPA | 19 | (16) | 9 | (13) | 10 | (19) | |
| GBM | 11 | (9) | 6 | (9) | 5 | (9) | |
| Unspecified ANCA vasculitis | 2 | (2) | 0 | (0) | 2 | (4) | |
| Time from Svv diagnosis to ICU admission, months | 1.5 | [0–58] | 0 | [0–0] | 48 | [4–132] | < 0.0001 |
| Svv diagnosis in ICU, n (%) | 55 | (45) | 51 | (76) | 4 | (7) | < 0.0001 |
| BVAS (Birmingham Vasculitis Activity Score) | 15 | [1–21] | 21 | [15–25] | 0 | [0–9] | < 0.0001 |
| Revised FFS (Five-factor score) | 1 | [0–2] | 1 | [1, 2] | 0 | [0–1] | 0.0004 |
| Clinical presentation upon ICU admission | |||||||
| Moderate-to-severe ARDS | 41 | (34) | 30 | (45) | 11 | (20) | 0.005 |
| Arterial hypertension | 25 | (21) | 14 | (21) | 11 | (20) | 0.943 |
| Shock | 20 | (17) | 7 | (10) | 13 | (24) | 0.045 |
| Neurological (GCS ≤ 13) | 19 | (16) | 8 | (12) | 11 | (20) | 0.205 |
| Time from respiratory symptoms to ICU admission, days, n (%) | 3 | [2–4] | 4 | [3, 4] | 2 | [1–3] | 0.0002 |
| < 3 days | 45 | (38) | 16 | (24) | 29 | (54) | 0.001 |
| ≥ 3 days | 76 | (63) | 51 | (76) | 25 | (46) | |
| Extra-respiratory symptomse, n (%) | 104 | (86) | 61 | (91) | 43 | (80) | 0.072 |
| Specific extra-respiratory symptomsf, n (%) | 63 | (52) | 47 | (70) | 16 | (30) | < 0.0001 |
| Laboratory features upon ICU admission | |||||||
| Hemoglobin, g/dl | 9.9 | [8–12] | 8.8 | [7.2–10.8] | 11 | [8.8–12.4] | 0.0012 |
| Leucocytes, giga/l | 13.0 | [8.2–16.5] | 13.9 | [9.2–18.2] | 10.7 | [7.2–15.6] | 0.020 |
| Plasma creatinine level, µmol/l | 200 | [88–398] | 229 | [79–422] | 188 | [96–300] | 0.75 |
| Hematuria [> 10^4/ ml, n (%)g | 54 | (45) | 44 | (66) | 10 | (19) | < 0.0001 |
| Positive ANCA and/or GBMg | 75 | (62) | 57 | (85) | 18 | (33) | < 0.0001 |
| Severity criteria upon ICU admission | |||||||
| SAPS II | 39 | [27–52] | 37 | [24–49] | 42 | [30–54] | 0.047 |
| SOFA | 6 | [4–8] | 6 | [3–8] | 5.5 | [4–8] | 0.667 |
| Vital support administered during the first 48 h, n (%) | |||||||
| Mechanical ventilation | 78 | (64) | 45 | (67) | 33 | (61) | 0.49 |
| Vasopressors | 34 | (28) | 18 | (27) | 16 | (30) | 0.113 |
| Renal replacement therapy | 48 | (40) | 28 | (42) | 20 | (37) | 0.595 |
Only the first admission was considered for the analysis of the characteristics of immune compared to non-immune ARF. Continuous variables are reported as median [interquartile range (IQR) 25–75]. Categorical variables are reported as number (percentages)
Svv small vessel vasculitis; BVAS Birmingham Vasculitis Activity Score; FFS Five-Factor Score; GPA granulomatosis with polyangiitis; MPA microscopic polyarteritis; EGPA eosinophilic GPA; GBM anti-GBM antibodies disease; ANCA anti-neutrophil cytoplasmic antibodies; GSC Glasgow Coma Scale; SAPSII and SOFA Simplified Acute Physiology Score II and Sequential Organ Failure Assessment score
aArterial hypertension, cardiac failure and/or ischemic heart disease
bCOPD or asthma or interstitial lung disease
cActive cancer, HIV or immunosuppressive treatment
dGlomerular filtration rate < 30 ml·min-1 over 1 month or more
eFever or asthenia or weight loss
fCutaneous (skin rash, purpura), rheumatic (arthralgia, arthritis, Raynaud’s syndrome, myalgia), neurological, gastrointestinal (abdominal pain, gastrointestinal bleeding), ENT (dysphonia, nasal crusts), lymphadenopathy
gData missing, respectively, for 11 patients and 13 patients (presence of hematuria and auto antibodies)