Background
Methods
Study design
Patient ID | Bacterial strain in blood | Toxin secretion | Toxin capable of haemolysis | P2X-dependent toxicity in vitro |
---|---|---|---|---|
#1 |
Escherichia coli
| Yes | Yes, α-haemolysin | Yes |
#2 | Methcillin-resistant Staphylococcus aureus | Yes | Yes, α-toxin | Yes |
#3 |
Escherichia coli
| Yes | Yes, α-haemolysin | Yes |
#4 | Staphylococcus aureus, coagulase positive | Yes | Yes, α-toxin | Yes |
#5 | Staphylococcus aureus, coagulase negative | Yes | No | Unknown |
#6 | Streptococcus anginosus (Miller) group | Yes. | Yes | Unknown |
#7 |
Bacterioides fragilis
| Yes. | No | Unknown |
#8 | Streptococcus anginosus (Miller) group | Yes. | Yes | Unknown |
#9 |
Escherichia coli
| Yes | Yes, α-hemolysin | Yes |
#10 | Clostridium difficile (toxiogenic) | Yes | Yes, β-toxin | Inconclusive |
#11 |
Escherichia coli
| Yes | Yes, α-haemolysin | Yes |
#12 |
Escherichia coli
| Yes | Yes, α-haemolysin | Yes |
#13 |
Aeromonas hydrophila
| Yes | Yes, | Unknown |
#14 | Candida (torulopsis) Glabrata | Yes | Unknown | Unknown |
Data handling
Haematocrit and haemoglobin assessment
Patient material
P2X receptor quantification
Measurement of vitamin D
Immunoblot experiments for method validation
Freeze-thaw control experiments
Material and solutions
Statistical analysis
Results
Characterisation of the patient demographics and clinical parameters
Demographics | Culture positive (n = 14) | Culture negative (n = 20) |
---|---|---|
Age, year | 65.5 (59.2–71) | 71 (65.5–78) |
Weight, kg | 82.95 (71.4–89.8) | 86.1 (68.9–99.8) |
Sex, female, n (%) | 6 (43) | 5 (20) |
Race, n (%) | ||
-White | 14 (100) | 18 (90) |
-Black | 0 (0) | 1 (5) |
-Other/not specified | 0 (0) | 1 (5) |
Time between blood samples from ER and ICU | 11.1 (6.6–13.3) | 9.7 (7.4–17.5) |
Time from admission to ER and to ICU | 2.7 (1.9–3.5) | 2.3 (1.7–5.12) |
length of stay in ICU, median (days) | 4.4 (1.0–6.75) | 3.6 (1.25–4.65) |
Length of stay in hospital, median (days) | 11.6 (6.25–13.75) | 10.5 (6.25–11.75) |
Laboratory values at admission to ER, median | ||
-Hct, median, % | 33.6 (29.4–39.2) | 36.8 (34.5–38) |
-Hgb | 10.7 (9.6–12.9) | 12.5 (11.4–13.5) |
-Monocyte count | 5.7 (3.3–8.0) | 3.5 (3.0–5.3) |
-White blood cell count | 13.3 (7.8–14.2) | 13.4 (9.6–15.8) |
-Platelet count | 283.5 (157.8–367) | 181.5 (135.0–246.8) |
-Lactate | 2.3 (1.6–3.1) | 1.9 (1.2–2.4) |
-MCV | 97 (89.5–102) | 90 (87.3–93.5) |
Laboratory values at admission to ICU, median | ||
-Hct | 30.5 (27.8–31.9) | 34.5 (31.6–37.6) |
-Hgb | 9.7 (8.8–10.8) | 11.3 (10.2–12.4) |
-Monocyte count | 4.6 (3.3–5.6) | 6 (2.2–7.3) |
-White blood cell count | 11.9 (7.2–18) | 11.4 (8.1–14.0) |
-Neutrophil granulocytes | 77.8 (69.5–79.8) | 82.5 (79.6–89.8) |
-Platelet count | 215.5 (131.3–325) | 167 (111.8–234.5) |
-Lactate | 2.6 (1.1–3.1) | 1.8 (1.1–2.4) |
-MCV | 97.5 (90.3–103) | 90.5 (85–94.3) |
-Vitamin D | 26.12 (17.22–32.13) | 23.35 (17.75–27.34) |
Vital signs at ICU admission | ||
-Heart rate, median, bpm | 111 (88–118) | 92 (78.8–106.5)) |
-Respiratory rate, median, rpm | 20 (17.5–22) | 20 (18.5–25.3) |
-Temperature, median, F | 99.5 (98–100) | 98.7 (98.1–99.1) |
-SBP, median, mmHg | 90.5 (83.3–97) | 88 (78.8–93.2) |
-DBP, median, mmHg | 47 (43.3–56) | 44.4 (36.5–48) |
-Saturation, median, % oxygen | 97 (96–99) | 96.5 (93.8–100) |
Outcome, n (%) | ||
-Home/home with service | 6 (43) | 11 (55) |
-Rehabilitation/nursing home | 7 (50) | 7 (35) |
-Deceased | 1 (7) | 2 (10) |
Characterisation of the patient P2X expression
P2X1 receptor expression on erythrocytes and change in haematocrit and haemoglobin
P2X dependant toxin activity | Haemolytic activity | Pathogen-positive | Pathogen-negative | |
---|---|---|---|---|
Correlation | Spearman r (confidence interval), n, p value | Spearman r (confidence interval), n, p value | Spearman r (confidence interval), n, p value | Spearman r (confidence interval), n, p value |
P2X1 expression and change in haematocrit | − 0.82 (exact), 7, 0.0341 | − 0.85 (− 0.95 to − 0.51), 11, 0.0015 | − 0.80 (− 0.93 to − 0.45), 14, 0.0010 | 0.19 (− 0.31 to 0.60), 20, 0.4459 |
P2X1 expression and change in haemoglobin | − 0.79 (exact), 7, 0.0480 | − 0.81 (− 0.95 to − 0.39), 11, 0.0039 | −0.78 (− 0.93 to − 0.41), 14, 0.0014 | 0.19 (− 0.30 to 0.61), 20, 0.4372 |
P2X7 expression and change in haematocrit | 0.2143 (exact), 7, 0.4444 | − 0.19 (− 0.72 to 0.48), 11, 0.5619 | 0..02 (− 0.53 to 0.56), 14, 0.9363 | 0.22 (− 0.28 to 0.62), 20, 0.3749 |
P2X7 expression and change in haemoglobin | 0.2143 (exact), 7, 0.3024 | − 0.18 (− 0.71 to 0.49), 11, 0.5894 | 0.02 (− 0.53 to 0.56), 14, 0.9363 | 0.03 (− 0.44 to 0.50), 20, 0.8922 |