Baseline characteristics of enrolled patients. During the study period, a total of 285 consecutive AIS patients undergoing i.v. thrombolysis treatment were enrolled in the study. Baseline characteristics of included patients are listed in Table 1. Mean age of the patients was 66 ±12.9 years, with 44.2% being female. Median baseline NIHSS score was 6 (IQR [5, 9.1]) and median 90-day mRS was 1.0. Patients with poor outcome (mRS ≥2) at 90 days after stroke were significantly older, had higher blood pressure and atrial fibrillation more frequently, and more severe neurologic deficit on admission as compared to those with a good outcome. Moreover, patients with poor outcome showed significantly higher NLR and significantly lower LMR as compared to those with good outcome (Table 1).
White blood cell counts, NLR and LMR during thrombolysis. In the total cohort, the median neutrophil count, monocyte count and NLR increased, whereas median LMR decreased 24 h after thrombolysis when compared with admission results (Table 2). An inverse but modest correlation was found between neutrophil count and lymphocyte count at admission (r = -0.166, p = 0.002), and at day 1 (r = -0.200, p = 0.001). Significant but modest positive correlation was found between lymphocyte count and monocyte count at admission (r = 0.261, p < 0.001), but not at day 1. Neutrophil count also correlated with monocyte count at admission (r=0.381, p < 0.001) and at day 1 (r = 0.598, p < 0.001).
None of the leukocyte indices showed association with stroke etiology, stroke severity at admission or with hemorrhagic transformation at admission (Table 3 and Supplementary Supplementary Table S1). On the other hand, neutrophil count, monocyte count and NLR significantly increased, while lymphocyte count and LMR significantly decreased 24 h post-rtPA
Table 1
Baseline characteristics of enrolled patients according to long term outcomes (modified Rankin Scale at 90 days post event). Results are depicted as mean ± SD or median (interquartile range). ACE angiotensin converting enzyme, ASPECTS Alberta Stroke Program Early CT Score, BA basilar artery, BMI body mass index, DM diabetes mellitus, hsCRP high sensitivity C reactive protein measurement, ICA internal carotid artery, LMR lymphocyte-monocyte ratio, mRS modified Rankin Scale, NIHSS National Institutes of Health Stroke Scale, NLR neutrophil-lymphocyte ratio, PAD peripheral artery disease, SICH symptomatic intracerebral hemorrhage, aSICH asymptomatic intracerebral hemorrhage, TIA transient ischemic attack, TOAST Trial of ORG 10172 in Acute Stroke Treatment, WBC white blood cell count.
| All Patients n = 285 | Good outcome (mRS=0-1) n = 190 | Poor outcome (mRS=2-6) n = 95 | p value |
Demographic characteristics | | | | |
Age (year) | 66 ± 12.9 | 62.8 ± 12.9 | 72.0 ± 10.2 | < 0.001 |
Gender, male (%) | 159 (55.8) | 107 (56.3) | 52 (54.7) | 0.802 |
BMI (kg/m2) Baseline laboratory results | 28.5 ± 5.9 | 28.5 ± 5.6 | 28.4 ± 6.5 | 0.900 |
High sensitivity C-reactive protein (g/L) | 2.8 (1.4-6.0) | 2.5 (1.3-5.2) | 3.5 (1.7-7.7) | 0.060 |
White blood cell count (G/L) | 8.1 (6.5-9.9) | 8.04 (6.45-9.59) | 8.15 (6.48-10.33) | 0.455 |
Neutrophil count (G/L) | 5.2 (4.0-7.1) | 5.12 (3.99-6.86) | 5.62 (4.17-7.55) | 0.157 |
Lymphocyte count (G/L) | 1.7 (1.2-2.3) | 1.77 (1.31-2.3) | 1.61 (1.15-2.24) | 0.053 |
Monocyte count (G/L) | 0.56 (0.44-0.69) | 0.54 (0.43-0.69) | 0.58 (0.47-0.71) | 0.164 |
NLR | 2.9 (1.94-4.82) | 2.72 (1.86-4.66) | 3.18 (2.17-5.94) | 0.036 |
LMR | 3.22 (2.42-4.29) | 3.41 (2.51-4.55) | 2.97 (1.87-3.92) | 0.005 |
Vascular risk factors | | | | |
Smoking, No. (%) | | | | |
Non-smoker | 204 (71.6) | 131 (68.8) | 73 (76.8) | 0.152 |
Previous smoker | 2 (0.7) | 2 (1.1) | 0 | |
Current smoker | 79 (27.7) | 57 (30.2) | 22 (23.2) | |
Previous stroke/TIA, No. (%) | 67 (23.5) | 38 (20) | 29 (30.5) | 0.055 |
Atrial fibrillation, No. (%) | 29 (10.2) | 14 (7.4) | 15 (15.8) | 0.026 |
PAD, No. (%) | 9 (3.2) | 6 (3.2) | 3 (3.2) | 1.000 |
Hyperlipidemia, No. (%) | 181 (63.5) | 123 (64.7) | 58 (61.0) | 0.602 |
DM, No. (%) | 71 (24.9) | 41 (21.6) | 30 (31.6) | 0.081 |
Hypertension, No. (%) | 246 (86.3) | 158 (83.2) | 88 (92.6) | 0.029 |
Therapy at stroke onset, No. (%) | | | | |
ACE inhibitor | 148 (51.9) | 92 (48.4) | 56 (58.9) | 0.103 |
Diuretic | 118 (41.4) | 71 (37.4) | 48 (50.5) | 0.056 |
Beta blocker | 97 (34) | 62 (32.6) | 35 (36.8) | 0.509 |
Calcium channel blocker | 69 (24.2) | 46 (24.2) | 23 (24.2) | 1.000 |
Alfa blocker | 23 (8.1) | 14 (7.4) | 9 (9.5) | 0.645 |
Hypertension therapy | 189 (66.3) | 121 (63.7) | 68 (71.6) | 0.231 |
Acetylsalicylic acid | 86 (30.2) | 52 (27.4) | 34 (35.8) | 0.171 |
Clopidogrel | 23 (8.1) | 16 (8.4) | 7 (7.4) | 0.822 |
Anticoagulant therapy, No. (%) | | | | |
Vitamin K antagonist | 9 (3.2) | 5 (2.6) | 4 (4.2) | |
Direct thrombin inhibitor | 1 (0.4) | 1 (0.5) | 0 | |
Direct factor Xa inhibitor | 0 | 0 | 0 | |
Low molecular weight heparin | 3 (1.1) | 2 (1.1) | 1 (1.1) | |
Lipid lowering therapy, No. (%) | 78 (25) | 44 (23.3) | 27 (28.4) | 0.384 |
Antidiabetic therapy, No. (%) | 52 (17) | 27 (14.2) | 21 (22.1) | 0.094 |
Stroke severity, No. (%) | | | | |
NIHSS at day 1 | | | | |
0-5 | 110 (38.7) | 93 (48.9) | 17 (18.1) | < 0.001 |
6-10 | 98 (34.5) | 65 (34.2) | 33 (35.1) | |
11-15 | 50 (17.6) | 24 (12.6) | 26 (27.7) | |
>15 | 26 (9.2) | 8 (4.2) | 18 (19.1) | |
NIHSS at day 7 | | | | |
0-5 | 129 (46.9) | 109 (57.7) | 20 (23.3) | < 0.001 |
6-10 | 113 (41.1) | 77 (40.7) | 36 (41.9) | |
11-15 | 24 (8.7) | 3 (1.6) | 21 (24.4) | |
>15 | 9 (3.3) | 0 | 9 (10.5) | |
Hemorrhagic transformation | | | | |
aSICH, No. (%) | 13 (4.6) | 4 (2.1) | 9 (9.5) | 0.110 |
SICH, No. (%) | 7 (2.5) | 0 | 7 (7.4) | |
Stroke localization | | | | |
ICA, No. (%) | 193 (67.7) | 112 (58.9) | 81 (85.3) | < 0.001 |
VB, No. (%) | 92 (32.3) | 78 (41.1) | 14 (14.7) | |
Stroke etiology (TOAST) | | | | |
Large-artery atherosclerosis, No. (%) | 62 (21.8) | 55 (28.9) | 7 (7.4) | < 0.001 |
Small-vessel occlusion, No. (%) | 103 (36.1) | 59 (31.1) | 44 (46.3) | |
Cardioembolic, No. (%) | 23 (8.1) | 17 (8.9) | 6 (6.3) | |
Other/undetermined, No. (%) | 97 (34) | 59 (31.1) | 38 (40) | |
Table 2
Leukocyte counts and ratios in acute ischemic stroke patients before and 24h after thrombolysis. NLR neutrophil-lymphocyte ratio, LMR lymphocyte-monocyte ratio, statistics: Wilcoxon Signed Rank test.
| Before thrombolysis | 24h after thrombolysis | p value |
Neutrophil (G/L) | 5.24 (4.04-7.14) | 6.26 (4.7-8.3) | < 0.001 |
Lymphocyte (G/L) | 1.74 (1.25-2.3) | 1.69 (1.28-2.15) | 0.061 |
Monocyte (G/L) | 0.56 (0.44-0.69) | 0.66 (0.53-0.83) | < 0.001 |
NLR | 2.9 (1.94-4.82) | 3.58 (2.48-5.6) | < 0.001 |
LMR | 3.22 (2.42-4.29) | 2.58 (1.74-3.56) | < 0.001 |
Table 3
Leukocyte counts and ratios at admission and 24h after thrombolysis according to stroke severity at admission and thrombolysis safety. Data depicted as median (inter-quartile range). NLR neutrophil- lymphocyte ratio, LMR lymphocyte- monocyte ratio, aSICH asymptomatic intracerebral hemorrhage, SICH symptomatic intracerebral hemorrhage, ECASS II European Co-operative Acute Stroke Study-II, NIHSS National Institutes of Health Stroke Scale. Statistics: Kruskal-Wallis.
| Time of blood sampling | Neutrophil (G/L) | Lymphocyte (G/L) | Monocyte (G/L) | NLR | LMR |
Hemorrhagic transformation according to ECASS II (24h post-lysis) | At admission | | | | | |
No hemorrhage (n = 264) | | 5.2 (4.1-7.1) | 1.7 (1.2-2.3) | 0.56 (0.44-0.70) | 2.88 (1.93-4.82) | 3.22 (2.42-4.30) |
aSICH (n = 13) | | 5.3 (3.8-7.2) | 1.7 (1.3-1.9) | 0.45 (0.39-0.58) | 3.07 (2.32-6.50) | 3.82 (2.68-5.10) |
SICH (n = 7) | | 6.2 (3.6-8.0) | 1.8 (1.4-2.2) | 0.60 (0.53-0.68) | 3.41 (1.96-4.54) | 2.97 (2.56-3.91) |
p value | | 0.987 | 0.688 | 0.152 | 0.805 | 0.551 |
Hemorrhagic transformation according to ECASS II (24 h post-lysis) | 24h after thrombolysis | | | | |
No hemorrhage (n = 264) | | 6.1 (4.6-8.2) | 1.7 (1.3-2.2) | 0.66 (0.52-0.83) | 3.44 (2.45-5.20) | 2.63 (1.75-3.59) |
aSICH (n = 13) | | 8.2 (6.6-9.1) | 1.3 (1.1-1.9) | 0.69 (0.62-0.87) | 5.63 (3.31-8.58) | 2.07 (1.2-2.59) |
SICH (n = 7) | | 9.7 (7.3-15.4) | 1.3 (0.8-2.2) | 0.91 (0.80-1.17) | 7.12 (4.15-19.74) | 1.51 (0.8-2.04) |
p value | | 0.002 | 0.091 | 0.030 | 0.002 | 0.005 |
Stroke severity at admission | At admission | | | | | |
NIHSS 0-5 (n = 110) | | 5.1 (4.0-7.0) | 1.8 (1.4-2.4) | 0.57 (0.44-0.71) | 2.75 (1.81-3.98) | 3.45 (2.51-4.51) |
NIHSS 6-10 (n = 97) | | 5.5 (4.4-6.8) | 1.7 (1.2-2.3) | 0.57 (0.45-0.70) | 2.78 (2.00-4.95) | 3.01 (2.33-4.34) |
NIHSS 11-16 (n = 50) | | 5.1 (4.0-7.5) | 1.6 (1.2-2.1) | 0.53 (0.42-0.66) | 2.99 (2.08-6.56) | 3.11 (2.41-4.13) |
NIHSS >16 (n = 25) | | 5.3 (3.6-6.9) | 1.6 (1.1-1.9) | 0.55 (0.44-0.63) | 3.27 (2.10-5.73) | 3.04 (2.36-4.06) |
p value | | 0.782 | 0.067 | 0.581 | 0.330 | 0.441 |
Stroke severity at admission | 24h after thrombolysis | | | | |
NIHSS 0-5 (n = 110) | | 5.4 (4.3-7.5) | 1.8 (1.4-2.4) | 0.61 (0.49-0.79) | 3.08 (2.10-4.47) | 2.95 (2.27-3.92) |
NIHSS 6-10 (n = 97) | | 6.4 (4.7-8.0) | 1.7 (1.4-2.2) | 0.66 (0.56-0.82) | 3.30 (2.48-5.17) | 2.54 (1.85-3.59) |
NIHSS 11-16 (n = 50) | | 7.7 (5.0-9.7) | 1.4 (1.2-2.0) | 0.67 (0.56-0.85) | 4.66 (3.04-6.85) | 2.26 (1.67-2.87) |
NIHSS >16 (n = 25) | | 9.7 (7.2-13.4) | 1.2 (0.9-1.7) | 0.83 (0.68-1.08) | 8.42 (4.05-12.98) | 1.34 (1.04-1.87) |
p value | | < 0.001 | < 0.001 | 0.004 | < 0.001 | < 0.001 |
in patients with more severe stroke. Similar pattern was seen in those who suffered therapy-associated intracerebral hemorrhage (Table 3).
Neutrophil count and NLR were significantly higher in ASPECTS 10-8 group compared with ASPECTS ≤7 group at day 1 (Supplementary Table S2). Univariate logistic regression proved a significant protective effect of higher LMR at admission against functional dependence at 3 months post-event (OR = 0.755, 95%CI [0.631, 0.903], p = 0.002) (Supplementary Table S3). Similar analysis showed no association between NLR and long-term functional outcome. Besides LMR, age, lymphocyte count at admission, hypertension and stroke characteristics (NIHSS, hemorrhagic transformation, stroke localization and etiology) showed association with long-term outcome of therapy, but in the multivariate model only age, NIHSS, hemorrhagic transformation and stroke localization remained as significant variables (Supplementary Table S3). Although in the univariate model, white blood cell counts, NLR and LMR measured at 24h after rtPA therapy showed highly significant association with functional outcomes at 3 months post-event, a multivariate logistic regression model including all possible confounders displayed no significant association of these parameters with 3-months functional outcome (Table 4).
Table 4
Univariable and multivariable logistic regression analyses depicting the associations of day 1 NLR, LMR and baseline characteristics with functional independence at 3 months post-event (mRS\(\ge\)2). ACE angiotensin converting enzyme, ASPECTS Alberta Stroke Program Early CT Score, BA basilar artery, BMI body mass index, DM diabetes mellitus, hsCRP high sensitivity C reactive protein measurement, ICA internal carotid artery, LMR lymphocyte-monocyte ratio, mRS modified Rankin Scale, NIHSS National Institutes of Health Stroke Scale, NLR neutrophil-lymphocyte ratio, PAD peripheral artery disease, SICH symptomatic intracerebral hemorrhage, aSICH asymptomatic intracerebral hemorrhage, TIA transient ischemic attack, TOAST Trial of ORG 10172 in Acute Stroke Treatment, WBC white blood cell count.
Parameters | Univariable Logistic Regression Analysis | | Multivariable Logistic Regression Analysis | |
| OR (95%CI) | p value | OR (95%CI) | p value |
Age (year) | 1.076 (1.048-1.105) | < 0.001 | 1.056 (1.011-1.111) | 0.014 |
Gender, male (%) | 0.938 (0.572-1.539) | 0.800 | | |
BMI (kg/1.72m2) | 0.997 (0.956-1.040) | 0.894 | | |
hsCRP (g/L) | 1.011 (1.001-1.022) | 0.038 | 1.005 (0.979-1.031) | 0.722 |
WBC (G/L) | 1.283 (1.173-1.402) | < 0.001 | 1.127 (0.796-1.595) | 0.502 |
Neutrophil (G/L) | 1.348 (1.221-1.489) | < 0.001 | 0.807 (0.527-1.237) | 0.325 |
Lymphocyte (G/L) | 0.403 (0.260-0.625) | < 0.001 | 8.299 (1.489-67.141) | 0.050 |
Monocyte (G/L) | 7.470 (2.818-19.802) | < 0.001 | 0.229 (0.094-2.426) | 0.117 |
NLR | 1.417 (1.266-1.585) | < 0.001 | 1.416 (0.963-2.083) | 0.077 |
LMR | 0.453 (0.347-0.591) | < 0.001 | 0.311 (0.103-1.413) | 0.056 |
Smoking, No. (%) | 0.654 (0.377-1.135) | 0.131 | 0.961 (0.732-4.296) | 0.204 |
Previous stroke/TIA, No. (%) | 1.758 (1.001-3.086) | 0.050 | 1.774 (0.732-4.296) | 0.204 |
Atrial fibrillation, No. (%) | 1.656 (1.086-2.527) | 0.019 | 0.347 (0.191-0.981) | 0.033 |
PAD, No. (%) | 1.000 (0.245-4.089) | 1.000 | | |
Hyperlipidemia, No. (%) | 0.854 (0.513-1.420) | 0.543 | | |
DM, No. (%) | 1.677 (0.964-2.918) | 0.067 | 1.148 (0.219-6.008) | 0.870 |
Hypertension, No. (%) | 2.546 (1.079-6.007) | 0.033 | 0.541 (0.117-2.493) | 0.430 |
Angiotensin converting enzyme inhibitor therapy | 0.654 (0.397-1.076) | 0.094 | 1.823 (0.570-5.829) | 0.311 |
Beta blocker therapy | 0.830 (0.496-1.390) | 0.480 | | |
Diuretic therapy | 0.609 (0.370-1.003) | 0.051 | 1.216 (0.459-3.217) | 0.694 |
Calcium channel blocker therapy | 1000 (0.563-1.777) | 1.000 | | |
Alfa blocker therapy | 0.760 (0.316-1.826) | 0.539 | | |
Hypertension therapy | 0.696 (0.480-1.189) | 0.185 | 1.028 (0.248-4.268) | 0.969 |
Acetylsalicylic acid therapy | 0.676 (0.399-1.145) | 0.145 | 0.593 (0.245-1.431) | 0.245 |
Clopidogrel therapy | 1.156 (0.459-2.914) | 0.759 | | |
Anticoagulant therapy, No. (%) | 1.025 (0.601-1.748) | 0.927 | | |
Lipid lowering therapy, No. (%) | 0.759 (0.434-1.327) | 0.334 | | |
Antidiabetic therapy, No. (%) | 0.548 (0.310-1.099) | 0.096 | 0.954 (0.156-5.821) | 0.595 |
NIHSS at day 1 | 2.333 (1.757-3.098) | < 0.001 | 0.925 (1.420-3.948) | 0.177 |
NIHSS at day 7 | 4.613 (2.949-7.215) | < 0.001 | 1.537 (1.335-1.769) | < 0.001 |
Hemorrhagic transformation | 6.874 (2.441-19.357) | < 0.001 | 4.102 (0.589-28.579) | 0.154 |
Stroke localization | 0.248 (0.131-0.469) | < 0.001 | 0.393 (0.137-1.131) | 0.083 |
Stroke etiology (TOAST) | 1.313 (1.060-1.626) | 0.013 | 1.104 (0.758-1.608) | 0.606 |
At baseline, the mean values of NLR and LMR for the study population were 2.9 (IQR [1.94, 4.82]) and 3.22 (IQR [2.42, 4.29]), respectively. The optimal threshold values for the prediction of poor functional outcome at 3 months post-event based on the best Youden index by ROC analysis were 5.73 for NLR and 2.08 for LMR (Fig. 1). According to the optimal cut-off values of NLR and LMR at admission, patients were classified into four groups: low NLR-high LMR, high NLR-high LMR, low NLR-low LMR, high NLR-low LMR.
Out of 190 patients with favorable outcome, 77% of patients fell in the category of low NLR-high LMR combinations, while the high NLR-low LMR group only 6.8% of patients at admission. The proportion of patients with favorable outcome as stratified according to low NLR-high LMR and high NLR-low LMR were 76% and 7.8% at day 1, respectively. Out of 95 patients in the poor outcome group, 67% of patients were stratified as low NLR-High LMR while only 21% as high NLR-low LMR before the administration of thrombolysis (p = 0.001) (Fig. 2). At 24h after thrombolysis, the proportion of patients with poor outcome displayed a significant shift in the above groups as 36% of patients could be stratified as having low NLR-high LMR while the high NLR-low LMR group included 49% (p < 0.001) of patients (Fig. 2).
The combination of NRL and LMR as determined at 24h after thrombolysis was found to be an independent predictor of poor functional outcome at 3 months post-event (OR = 3.407, 95% CI [1.449, 8.011], p = 0.005 for high NLR-low LMR patient group vs. low NRL-high LMR patient group) after controlling for all potential confounders (Table 5).
Table 5
Association of NLR-LMR combinations at admission and 24h after thrombolysis with poor functional outcome (mRS ≥2) at 3 months post-event. CI confidence interval, OR odds ratio, NLR neutrophil-lymphocyte ratio, LMR monocyte-lymphocyte ratio. a Controlled for: age, sex, atrial fibrillation, hypertension, NIHSS at day 1, hemorrhagic transformation, stroke localization, stroke etiology (TOAST).
Characteristics | Univariate Analysis, OR (95% CI) | p value | Multivariate Analysis, OR (95% CI)a | p value |
At admission | | | | |
Low NLR-High LMR (n=211) | Ref | - | Ref | - |
High NLR-High LMR n=22) | 0.766 (0.310-1.891) | p = 0.563 | 0.338 (0.075-1.530) | p = 0.159 |
Low NLR-Low LMR (n=19) | 0.993 (0.516-1.914) | p = 0.507 | 1.486 (0.462-4.779) | p = 0.507 |
High NLR-Low LMR (n=33) | 5.496 (3.236-9.336) | p < 0.001 | 3.049 (1.205-7.714) | p = 0.019 |
At day 1 | | | | |
Low NLR-High LMR (n=178) | Ref | - | Ref | - |
High NLR-High LMR n=10) | 1.412 (0.555-3.591) | p = 0.469 | 4.860 (0.816-28.944) | p = 0.082 |
Low NLR-Low LMR (n=35) | 1.831 (0.914-3.671) | p = 0.088 | 1.168 (0.439-3.107) | p = 0.755 |
High NLR-Low LMR (n=62) | 10.134 (5.685-18.066) | p < 0.001 | 6.353 (2.774-14.548) | p < 0.001 |