Background
Methods
Study area
Study design and patient enrolment
Sample collection
DNA preparation
CRP genotyping with pyrosequencing
Measurement of CRP
Measurement of specific IgG and IgG subclasses by enzyme-linked immunosorbent assays (ELISA)
Ethical considerations
Statistical analysis
-
OR = 1 Represents no statistical significance
-
OR > 1 Represents significance associated with the EOS group
-
OR < 1 Represents significance associated with the suspected or sepsis free control
Results
Characteristics of the study participants
Study groups variables | Sepsis- free controls n = 68 | Suspected n = 68 | Early onset sepsis n = 69 |
P value
|
---|---|---|---|---|
Sex: girls n(%)
| 37 (54.4%) | 25 (36.8%) | 26 (37.7%) | 0.06 |
Boys n(%)
| 31 (45.6%) | 43 (63.2%) | 43 (62.3%) | |
Nationality: non-Saudi n(%)
| 8 (11.8%) | 4 (5.9%) | 7 (10.1%) | 0.48 |
Saudi n(%)
| 60 (88.2%) | 64 (94.1%) | 62 (89.9%) | |
Median (range) of:
| ||||
Age/ day
| 1 (1-2) | 1 (1-2) | 1 (1-1) |
<0.091
|
Weight/g
| 3390 (3095–4960) | 2780 (2375–3175) | 2030 (1335–2021) |
<0.001
|
Temperature/°C
| 36.7 (35.5–37.0) | 35.3 (34.6–35.9) | 35.5 (35.0–37.5) |
<0.001
|
CRP ng/ml
| 0.35 (0.04–0.86) | 3.46 (2.15–4.71) | 6.43 (3.77–8.25) |
<0.001
|
IgG
| 0.70 (0.25–3.70) | 2.05 (0.25–17.90) | 0.57 (0.24–7.90) |
<0.001
|
IgG1
| 2.19 (0.08–8.70) | 5.60 (0.28–22.27) | 3.20 (0.36–10.22) |
<0.001
|
IgG2
| 0.68 (0.28–1.00) | 8.37 (0.22–25.89) | 1.52 (1.02–2.81) |
<0.001
|
IgG3
| 4.48 (0.15–14.24) | 6.50 (0.31–39.45) | 4.78 (0.15–27.58) |
<0.001
|
IgG4
| 0.28 (0.13–0.96) | 0.34 (0.10–3.24) | 0.39 (0.08–2.28) |
0.001
|
TWBCs/ 10
3
cells/
μl
| 10.43 (6.9–12.5) | 14.45 (12.5–17.1) | 21.72 (17.1–19.3) |
<0.001
|
Neutrophils%
| 3.24 (0.4–5.2) | 7.17 (5.2–9.1) | 12.25 (9.3–12.5) |
<0.001
|
Lymphocytes%
| 3.27 (0.78– 4.0) | 4.79 (4.02–5.45) | 6.76 (5.49–10.00) |
<0.001
|
Monocytes%
| 0.49 (0.09–0.71) | 1.51 (1.18–3.10) | 1.5 (1.18–3.10) |
<0.001
|
CRP genotypes, allele and allele carrier frequencies
CRP genotypes* | Sepsis- free controls n = 68 (%) | Suspected n = 68 (%) | Early onset sepsis n = 69 (%) |
Hardy-Weinberg equilibrium test
|
---|---|---|---|---|
TT
| 10 (14.7%) | 2 (2.9%) | 13 (18.8%) | 0.201 |
AA
| 3 (4.4%) | 15 (22.1%) | 1 (1.4%) | |
AC
| 19 (27.9%) | 30 (44.1%) | 10 (14.5%) | |
AT
| 13 (19.1%) | 7 (10.3%) | 8 (11.6%) | |
CC
| 18 (26.5%) | 8 (11.8%) | 21 (30.4%) | |
CT
| 5 (7.4%) | 6 (8.8%) | 16 (23.2%) | |
Alleles frequency
‡
| ||||
C
| 0.44 | 0.38 | 0.50 | |
T
| 0.28 | 0.13 | 0.36 | |
A
| 0.27 | 0.49 | 0.14 | |
Allele carriers
§
| ||||
Non- A- Allele
| 33 (48.5%) | 16 (23.5%) | 49 (71.0%) | |
A- Allele
| 35 (51.5%) | 52 (76.5%) | 20 (29.0%) |
CRP genotypes | OR (95% CI) | P value |
---|---|---|
TT
| 1.00 | |
AA
| 0. 10 (0.01–1.27) |
<0.001
|
AC
| 0.05 (0.01–0.27) |
<0.001
|
AT
| 0.18 (0.03–1.07) | 0.059 |
CC
| 7.88 (2.66–13.29) |
<0.001
|
CT
| 8.00 (2.46–16.04) |
0.001
|
Alleles frequency
| ||
C
| 2.48 (0.97–6.37) | 0.059 |
T
| 1.00 | |
A
| 0.24 (0.10–0.57) |
0.001
|
Alleles carriers frequency
| ||
Non-A-allele
| 0.13 (0.06–0.27) |
<0.001
|
A-allele
|
Circulating CRP concentrations
CRP levels ng/ml | OR (95% CI) | p value |
---|---|---|
Less than 0.239
| 0.52 (0.22–1.21) | 0.129 |
Within 0.240 to 1.300
| 1.00 | |
Higher than 1.301
| 2.31 (1.16–4.59) |
0.005
|
Analysis of CRP concentrations in relation to CRP-286 allele carriers
CRP levels ng/ml | OR (95% CI) | p value |
---|---|---|
Less than 0.239
| 0.38 (0.18–0.77) |
0.007
|
Within 0.240 to 1.300
| 1.00 | |
Higher than 1.301
| 3.24 (1.53–6.87) |
0.002
|
Patterns of specific IgG/IgG subclass antibodies in relation to relative risk of sepsis infection
Antibody isotopes | Categorized IgG subclasses levels | OR (95% CI) | P value |
---|---|---|---|
IgG
|
Lower level
| 1.00 | |
Medium level
| 0.69 (0.29–1.62) | 0.394 | |
Higher level
| 0.213 (0.09–0.51) |
<0.001
| |
IgG1
|
Lower level
| 1.00 | |
Medium level
| 1.34 (0.51–3.50) | 0.558 | |
Higher level
| 0.30 (0.12–0.76) |
0.011
| |
IgG2
|
Lower level
| 1.00 | |
Medium level
| 0.44 (0.37– 0.73) |
0.001
| |
Higher level
| 0.34 (0.20–0.49) |
0.030
| |
IgG3
|
Lower level
| 1.00 | |
Medium level
| 0.44 (0.18–1.07) | 0.070 | |
Higher level
| 0.32 (0.13–0.75) |
0.009
| |
IgG4
|
Lower level
| 1.00 | |
Medium level
| 2.82 (1.16–6.90) |
0.023
| |
Higher level
| 1.71 (0.73–4.00) | 0.213 |
Concentration of serum CRP levels in relation to relative risk of high levels of specific IgG/IgG subclass antibodies
Antibody isotopes | Categorized CRP levels | OR (95% CI) | P value |
---|---|---|---|
IgG
|
Less than 0.239
| 1.00 | |
Within 0.240 to 1.300
| 0.57 (0.29–1.12) | 0.102 | |
Higher than 1.301
| 1.310 (0.66–2.57) | 0.434 | |
IgG1
|
Less than 0.239
| 1.00 | |
Within 0.240 to 1.300
| 1.30 (0.66–2.55) | 0.444 | |
Higher than 1.301
| 1.46 (0.75–2.87′) | 0.268 | |
IgG2
|
Less than 0.239
| 1.00 | |
Within 0.240 to 1.300
| 0.44 (0.35–3.05) | 0.202 | |
Higher than 1.301
| 0.74 (0.35–1.06) |
0.034
| |
IgG3
|
Less than 0.239
| 1.00 | |
Within 0.240 to 1.300
| 1.23 (0.63–2.40) | 0.552 | |
Higher than 1.301
| 1.55 (0.79–3.047) | 0.201 | |
IgG4
|
Less than 0.239
| 1.00 | |
Within 0.240 to 1.300
| 1.23 (0.63–2.40) | 0.548 | |
Higher than 1.301
| 0.86 (0.44–1.69) | 0.862 |