The frequency of steatosis in donors for liver transplantation (LT) is increasing over time, showing similar trends as the general population. Most studies exploring the effect of steatosis on LT outcomes classify it as “macrovesicular” or “microvesicular” steatosis [
Poor clarity exists also on a clear histological definition of macro- and microvesicular steatosis. In this respect, an accurate classification of hepatic steatosis has been proposed by Brunt, classifying the steatosis as (a) large droplet macrovesicular (Ld-MaS), (b) small-droplet macrovesicular (Sd-MaS), and (c) true microvesicular steatosis [
Another underestimated aspect to consider is the potential confounding role of HCV infection when we analyze the association between allograft steatosis and post-LT including (a) HCV interaction with lipid metabolism in the hepatocytes [
The principal aim of the study was to investigate the impact of allograft steatosis, reclassified according to the Brunt classification, on early graft function and survival after LT. Separate analyses were done in HCV-negative (HCV-) and HCV-positive (HCV+) patients. The secondary aim was to evaluate the ATP levels in the donor livers according to the type and percentages of steatosis.
During the study period (February 27th, 2001-July 28th, 2011), 233 consecutive adult (≥18 years) patients received a first, nonurgent, deceased-donor, whole-organ LT at Sapienza University of Rome Liver Transplant Center, Italy. Protocol preperfusion donor liver biopsies were prospectively collected for all patients and retrospectively evaluated for reestimating the donor steatosis according to the Brunt classification.
As shown in Figure
Study population. (a) Flow chart of liver graft loss according to HCV status and Sd-MaS percentage. (b) Graft Ld-MaS distribution in the HCV- and HCV+ groups. (c) Graft Sd-MaS distribution in the HCV- and HCV+ groups.
All transplants were performed with a terminoterminal choledochocholedochostomy with T-tube placement. The immunosuppressive protocol was based on a triple therapy with methylprednisolone, mycophenolate mofetil, and calcineurin inhibitor (cyclosporine=40 patients; tacrolimus=166 patients). Methylprednisolone was rapidly tapered. Donor and recipient data were prospectively collected using an in-house database and retrospectively reviewed; donor information was supplemented by data held in the National Transplant Center database. Initial Poor Graft Function (IPGF) was defined according to Nanashima et al. [
Permanent histological sections were prospectively collected from allograft preischemia liver wedge biopsies performed on the left hepatic lobe. The liver tissue was immediately fixed in 10% formalin and within few days was embedded in paraffin and then stained with hematoxylin and eosin, to assess hepatic steatosis in all transplants. To grade the severity of ischemia-reperfusion injury (IRI), permanent histological sections in the recipient within 1 hour after complete revascularization of the allograft (postreperfusion biopsy) were obtained in 134 cases (79 HCV- and 55 HCV+ patients, respectively) with the same procedure.
Frozen-section evaluation was performed in selected cases based on gross appearance of the graft only to decide whether to discard the graft. Two expert pathologists (AC and MR), blinded to clinical data and to the frozen-section evaluation, retrospectively reviewed and scored all the preischemia liver samples for steatosis, defined according to the Brunt classification [
Representative images of Ld-MaS (a), Sd-MaS (b), and true microvesicular steatosis (c). In (a), a single fat vacuole displaced the nucleus to periphery of the cell. In contrast, multiple fat vacuoles not displacing the nucleus were considered the hallmark of (b). In (c) steatosis was true microvesicular when many tiny lipid vesicles were diffusely distributed within the cytoplasm leading to a foamy appearance.
Continuous variables are presented as median and interquartile ranges (IQR). After assessment of normality by the Kolmogorov-Smirnov test, the differences between groups were evaluated by Mann-Whitney
All the analyses were performed separately in patients with HCV- and HCV+ liver disease.
Survival rates were calculated using the Kaplan-Meier method. In order to calculate graft survival, patients alive and not retransplanted were censored at the date of last follow-up, while time to graft loss was measured from LT to patient death or retransplantation. Patient-, donor-, graft-, and transplant-specific risk factors for overall graft survival were investigated using univariable Cox regression analyses. Different multivariable Cox regression models were constructed, considering as covariates only pre-/intraoperative variables or both pre-/intraoperative and early postoperative variables. Hazard ratios (HR) and 95% confidence intervals (95%CI) were reported.
To investigate donor factors independently associated with graft Sd-MaS >15% compared to a lower degree of Sd-MaS or nil Sd-MaS, we used logistic binary regression.
Variables with a
A
The recipient, donor, graft, intraoperative, and early postoperative characteristics of the entire study population are shown in Table
Recipient, donor, graft, intraoperative, and early postoperative characteristics of the entire study population and according to recipient etiology of liver disease (HCV negative versus HCV positive).
All patients |
HCV positive |
HCV negative |
| ||
---|---|---|---|---|---|
RECIPIENT | Age (years) | 56.00 (49.14-61.00) | 57.00 (49.00-61.00) | 55.50 (49.75-61.25) | 0.510 |
Gender (female) | 49 (24.0) | 22 (26.8) | 27 (22.1) | 0.441 | |
MELD score | 15.20 (12.26-18.65) | 14.73 (12.46-18.85) | 15.72 (11.78-18.15) | 0.549 | |
BMI (kg/m2) | 25.46 (23.28-28.47) | 26.23 (23.91-28.64) | 25.06 (23.04-28.34) | 0.184 | |
HCC (yes vs no) | 78 (38.2) | 32 (39.0) | 46 (37.7) | 0.849 | |
|
|||||
DONOR | Age (years) | 50.50 (33.25-64.00) | 48.00 (31.00-65.00) | 51.00(34.00-64.00) | 0.703 |
Gender (female) | 84 (41.2) | 32 (39.0) | 52 (42.6) | 0.609 | |
BMI (kg/m2) | 24.83 (23.44-27.06) | 24.69 (23.44-26.15) | 25.39 (23.61-27.34) | 0.131 | |
Cause of death |
132 (65.7) | 50 (61) | 82 (68.9) | 0.244 | |
ALT (IU/L) | 33.00 (18.00-58.50) | 33.00 (18.00-59.00) | 32.50 (17.75-58.50) | 0.562 | |
AST (IU/L) | 37.50 (25.00-70.50) | 45.50 (24.00-83.00) | 36.00 (25.00-58.50) | 0.174 | |
Sodium (mEq/L) | 149.00 (142.25-157.00) | 150.00 (142.00-157.00) | 149.00 (144.00-157.00) | 0.804 | |
Hemoglobin (gr/dL) | 10.50 (9.30-12.20) | 10.40 (9.00-11.90) | 10.70 (9.50-12.30) | 0.440 | |
PaO2 (mmHg) | 150.50 (102.93-202.08) | 148.90 (111.50-217.50) | 151.00 (98.00-198.00) | 0.776 | |
Anti-HBc status (pos vs neg) | 18 (8.8) | 3 (3.7) | 15 (12.3) |
|
|
Norepinephrine (yes vs no) | 98 (49.0) | 33 (40.7) | 65 (54.6) | 0.054 | |
ICU stay (days) | 3.00 (2.00-7.00) | 3.00 (2.00-6.00) | 4.00 (2.00-8.00) | 0.113 | |
|
|||||
GRAFT | Sd-MaS categorical, n (%): | ||||
0% | 118 (57.8) | 49 (59.8) | 69 (56.6) | 0.613 | |
1-15% | 52 (25.5) | 18 (22.0) | 34 (27.9) | ||
>15% | 34 (16.7) | 15 (18.3) | 19 (15.6) | ||
Sd-MaS, continuous variable |
0.00 (0.00-5.00) | 0.00 (0.00-10.00) | 0.00 (0.00-5.00) | 0.969 | |
Ld-MaS categorical, n (%): | |||||
0% (reference) | 88 (43.1) | 39 (47.6) | 49 (40.2) | 0.530 | |
1-15% | 92 (45.1) | 35 (42.7) | 57 (46.7) | ||
>15% | 24 (11.8) | 8 (9.8) | 16 (13.1) | ||
Ld-MaS, continuous variable |
2.00 (0.00-9.00) | 1.00 (0.00-5.00) | 2.00 (0.00-10.00) | 0.245 | |
Cold ischemia time (minutes) | 361.00 (280.75-415.00) | 357.50 (270.00-421.25) | 362.50 (298.25-410.00) | 0.606 | |
Warm ischemia time (minutes) | 60.00 (47.50-77.75) | 60.00 (45.75-87.75) | 60.00 (48.50-75.00) | 0.316 | |
IRI score, categorical§ |
40 (29.9) | 19 (34.5) | 21 (26.6) | 0.322 | |
IPGF (yes vs no) | 37 (18.3) | 15 (18.5) | 22 (18.2) | 0.952 | |
EAD (yes vs no) | 112 (54.9) | 48 (58.5) | 64 (52.5) | 0.392 | |
Transplant year | 6.00 (3.00-8.75) | 5.00 (3.00-7.00) | 6.00 (3.00-9.00) | 0.105 |
MELD, model for end-stage liver disease score; HCC, hepatocellular carcinoma; PaO2, partial pressure of oxygen in arterial blood; ICU, intensive care unit; Sd-MaS, small droplet macrovesicular steatosis; Ld-MaS, large droplet macrovesicular steatosis; IRI, histological ischemia/reperfusion injury; IPGF, initial poor graft function; EAD, early allograft dysfunction. Continuous variable is expressed as median (25th-75th percentile); the differences between groups were evaluated by Mann-Whitney
§Available in only 55 and 79 recipients with HCV positive and negative liver disease, respectively.
In the entire study population, median follow-up was 7.5 years (range: 0.0-16.7). Comparing HCV- versus HCV+ patients, the only difference was that Anti-HBc positive donors were less frequently allocated to HCV+ patients (
In the HCV- group, the median follow-up was 7.8 years (range: 0.0-16.7). During the follow-up period, 28 grafts (22.9%) were lost for liver-related causes. In detail, we observed nine cases of delayed graft dysfunctions, six ischemic cholangitides, four primary nonfunctions, three HCC recurrences, two hepatic artery thromboses, one acute rejection, one chronic rejection, one recurrence of primary biliary cholangitis, and one portal thrombosis. Fifteen (12.3%) liver-unrelated causes for graft loss were observed (six de novo malignancies, three cerebrovascular accidents, three acute myocardial infarctions, two cases of sepsis, and one multiorgan failure). One-, 3-, and 5-year graft survival rates were 82.8%, 76.2%, and 71.3%, respectively. As shown in Figure
Univariable Cox regression analyses for overall graft loss according to recipient etiology of liver disease (HCV negative versus HCV positive).
|
|
||||||
---|---|---|---|---|---|---|---|
|
(95% CI) |
|
|
(95% CI) |
|
||
RECIPIENT | Age (years) | 0.988 | 0.951-1.026 | 0.517 | 0.998 | 0.973-1.024 | 0.892 |
Gender (female vs male) | 1.794 | 0.954-3.376 | 0.070 | 1.052 | 0.518-2.135 | 0.888 | |
MELD score | 0.993 | 0.928-1.063 | 0.845 | 1.050 | 0.993-1.110 | 0.089 | |
BMI (kg/m2) | 1.065 | 0.967-1.173 | 0.204 | 1.001 | 0.929-1.079 | 0.979 | |
HCC (yes vs no) | 1.139 | 0.616-2.103 | 0.678 | 1.338 | 0.734-2.439 | 0.342 | |
|
|||||||
DONOR | Age (years) | 1.009 | 0.993-1.026 | 0.284 | 1.014 | 0.996-1.032 | 0.119 |
Gender (female vs male) | 0.983 | 0.530-1.821 | 0.955 | 1.326 | 0.729-2.413 | 0.355 | |
BMI (kg/m2) | 1.034 | 0.919-1.162 | 0.580 | 0.954 | 0.869-1.046 | 0.314 | |
Cause of death |
1.014 | 0.544-1.891 | 0.965 | 0.867 | 0.456-1.650 | 0.663 | |
ALT (IU/L) | 1.000 | 0.995-1.005 | 0.948 | 0.998 | 0.992-1.004 | 0.590 | |
AST (IU/L) | 0.996 | 0.990-1.002 | 0.148 | 0.999 | 0.993-1.005 | 0.797 | |
Sodium (mEq/L) | 1.008 | 0.979-1.038 | 0.594 | 0.995 | 0.964-1.027 | 0.742 | |
Hemoglobin (gr/dL) | 0.993 | 0.868-1.137 | 0.923 | 1.049 | 0.916-1.201 | 0.491 | |
PaO2 (mmHg) | 1.000 | 0.996-1.004 | 0.872 | 0.999 | 0.995-1.002 | 0.557 | |
Anti-HBc status (pos vs neg) | 1.424 | 0.344-5.902 | 0.626 | 3.190 | 1.565-6.501 |
|
|
Norepinephrine (yes vs no) | 1.512 | 0.813-2.811 | 0.191 | 0.588 | 0.315-1.0.97 | 0.095 | |
ICU stay (days) | 1.121 | 1.022-1.229 |
|
0.555 | 0.954-1.091 | 0.555 | |
|
|||||||
GRAFT | Sd-MaS categorical, n (%): | ||||||
0% | |||||||
1-15% | 0.939 | 0.453-1.948 | 0.866 | 1.284 | 0.622-2.647 | 0.499 | |
>15% | 0.581 | 0.239-1.415 | 0.232 | 3.146 | 1.525-6.489 |
|
|
Sd-MaS, continuous variable |
0.983 | 0.958-1.010 | 0.212 | 1.036 | 1.018-1.055 |
|
|
Ld-MaS categorical, n (%): | |||||||
0% (reference) | |||||||
1-15% | 0.841 | 0.445-1.586 | 0.592 | 0.694 | 0.360-1.337 | 0.275 | |
>15% | 0.650 | 0.194-2.177 | 0.484 | 1.430 | 0.654-3.129 | 0.371 | |
Ld-MaS, continuous variable |
0.983 | 0.944-1.024 | 0.406 | 1.016 | 0.992-1.040 | 0.193 | |
Cold ischemia time (minutes) | 1.007 | 1.003-1.010 |
|
1.001 | 0.998-1.005 | 0.364 | |
Warm ischemia time (minutes) | 1.015 | 1.003-1.027 |
|
0.997 | 0.982-1.012 | 0.718 | |
IRI score, categorical§ |
2.932 | 1.399-6.145 |
|
0.961 | 0.365-2.527 | 0.935 | |
IPGF (yes vs no) | 3.340 | 1.694-6.584 |
|
2.152 | 1.100-4.212 |
|
|
EAD (yes vs no) | 1.839 | 1.004-3.371 |
|
2.346 | 1.252-4.396 |
|
|
Transplant year | 0.954 | 0.854-1.067 | 0.411 | 0.900 | 0.816-0.993 |
|
MELD, model for end-stage liver disease score; HCC, hepatocellular carcinoma; BMI, body mass index; PaO2, partial pressure of oxygen in arterial blood; ICU, intensive care unit; Sd-MaS, small droplet macrovesicular steatosis; Ld-MaS, large droplet macrovesicular steatosis; IRI, histological ischemia/reperfusion injury; IPGF, initial poor graft function; EAD, early allograft dysfunction.
§Available in only 55 and 79 recipients with HCV positive and negative liver disease, respectively.
Two multivariable Cox regression models were created (Table
Multivariable Cox regression models for overall graft loss in recipients with HCV negative liver disease.
|
|
|||||
---|---|---|---|---|---|---|
|
(95% CI) |
|
|
(95% CI) |
|
|
Donor anti-HBc serum status |
3.303 | 1.601-6.814 |
|
2.855 | 1.329-6.134 |
|
Sd-MaS categorical, n (%): |
||||||
1-15% | 1.223 | 0.587-2.547 | 0.591 | 1.357 | 0.641-2.871 | 0.425 |
>15% | 2.891 | 1.312-6.369 |
|
2.623 | 1.169-5.888 |
|
IPGF (yes vs no) | 1.094 | 0.494-2.426 | 0.824 | |||
EAD (yes vs no) | 1.849 | 0.891-3.838 | 0.099 | |||
Transplant year | 0.947 | 0.851-1.053 | 0.315 | 0.969 | 0.863-1.087 | 0.589 |
Sd-MaS, small droplet macrovesicular steatosis; IPGF, initial poor graft function; EAD, early allograft dysfunction.
Although not significant in the univariate model, we decided to test the Ld-MaS in separate analyses, with the main intent to exclude a possible effect of coexisting Sd-MaS and Ld-MaS on graft loss. After having constructed the same multivariable models based on pre-/intraoperative and pre-/intra-/postoperative variables plus the variable Ld-MaS, Sd-MaS >15%, we confirmed its independent role of Sd-MaS >15% as a risk factor for graft loss, with HRs 3.311 (
Kaplan-Meier curves reporting the graft loss rates stratified for Ld-MaS >15% (Figure
Cumulative overall graft survival rate according to graft large droplet (Ld-MaS; (a-c)) and small-droplet (Sd-MaS; (b-d)) macrovesicular steatosis distribution in recipients with HCV unrelated ((a), (b)) and related ((c), (d)) liver disease.
Cumulative overall graft survival rate according to graft histological ischemia/reperfusion injury severity in recipients with HCV unrelated (a) and HCV-related (b) liver disease.
Figure
First three days after operative serum AST peak according to graft large droplet (Ld-MaS) and small-droplet (Sd-MaS) macrovesicular steatosis distribution in recipients with HCV unrelated (a) and related (b) liver disease.
The median follow-up was 7.1 years (range: 0.0-16.7). During follow-up, 32 grafts (39.0 %) were lost for liver-related causes. Specifically, we observed 19 recurrences of HCV-related cirrhosis, five delayed graft dysfunctions, two primary nonfunctions, two HCC recurrences, one hepatic artery thrombosis, one chronic rejection, one ischemic cholangitis, and one hepatic artery aneurysm. Ten (12.2%) grafts were lost due to liver-unrelated causes: five cerebrovascular accidents, one de novo malignancy, one sepsis, one acute myocardial infarction, one pulmonary embolism, and one intra-abdominal hemorrhage. One-, 3-, and 5-year graft survival rates were 75.6%, 67.1%, and 63.4%, respectively. As shown in Figure
At multivariable Cox regression analyses (Table
Multivariable Cox regression models for overall graft loss in recipients with HCV positive liver disease.
|
|
|||||
---|---|---|---|---|---|---|
|
(95% CI) |
|
|
(95% CI) |
|
|
Donor ICU stay (days) | 1.078 | 0.983-1.182 | 0.112 | 0.967 | 0.855-1.094 | 0.596 |
Graft cold ischemia time (minutes) | 1.006 | 1.003-1.010 |
|
1.004 | 1.000-1.008 | 0.050 |
Graft warm ischemia time (minutes) | 1.011 | 0.999-1.024 | 0.073 | 1.017 | 0.998-1.035 | 0.077 |
IRI score, categorical (severe vs mild/moderate)§ | 4.485 | 1.755-11.459 |
|
|||
IPGF (yes vs no) | 5.074 | 1.499-17.170 |
|
|||
EAD (yes vs no) | 0.921 | 0.370-2.292 | 0.860 |
ICU, intensive care unit; IRI, histological ischemia/reperfusion injury; IPGF, initial poor graft function; EAD, early allograft dysfunction.
§Available in only 55 patients.
No statistical differences were found in terms of survival rates when the cohort of HCV+ patients was stratified according to Ld-MaS and Sd-MaS values (Figures
In HCV+ patients, serum AST peaks observed during the first 3 postoperative days did not differ according to both Sd-MaS and Ld-MaS distribution (Figures
Since the negative effects on postoperative aminotransferases and graft survival were observed in case of Sd-MaS >15%, we investigated the donor-specific factors associated with a Sd-MaS >15%. At univariable logistic regression analysis, risk factors for Sd-MaS >15% were a higher donor BMI (
Univariable and multivariable binary logistic regression analysis of donor variables associated with graft Sd-MaS.
Sd-MaS≤ 15% (n=170) | Sd-MaS >15% (n=34) | P | OR | (95% CI) | P | |
---|---|---|---|---|---|---|
Age (years) | 50.00 (33.00-65.00) | 52.00 (39.00-61.25) | 0.790 | |||
Gender (female versus male) | 75 (44.1) | 9 (26.50) | 0.056 | |||
BMI (kg/m2) | 24.69 (23.44-26.36) | 26.12 (24.05-27.71) |
|
1.124 | 0.994-1.271 | 0.063 |
Cause of death |
114 (67.9) | 18 (54.50) | 0.141 | |||
ALT (IU/L) | 33.00 (18.00-58.00) | 33.00 (21.00-63.00) | 0.476 | |||
AST (IU/L) | 36.00 (25.00-69.00) | 49.00 (28.00-78.00) | 0.146 | |||
Sodium (mEq/L) | 149.00 (142.00-154.00) | 150.00 (142.50-163.50) | 0.180 | |||
Hemoglobin (g/dL) | 10.40 (9.05-12.10) | 11.00 (9.80-13.20) | 0.075 | |||
PaO2 (mmHg) | 154.80 (107.00-219.00) | 122.00 (89.50-168.50) |
|
0.993 | 0.986-0.999 |
|
Anti-HBc status (pos vs neg) | 13 (7.6) | 5 (14.7) | 0.185 | |||
Norepinephrine (yes vs no) | 86 (51.5) | 12 (36.4) | 0.112 | |||
ICU stay (days) | 4.00 (2.00-7.00) | 3.00 (2.00-4.00) |
|
0.851 | 0.740-0.978 |
|
Data are reported as means and standard deviations for normally distributed or medians (25th-75th percentile) for nonnormally distributed ones. Absolute and relative frequencies are reported for categorical ones.
Differences between groups were tested with Mann-Whitney
PaO2, partial pressure of oxygen in arterial blood; ICU, intensive care unit.
A subanalysis was performed in a cohort of 42 grafts in which we measured preischemia and postreperfusion hepatic ATP content (Figure
Graft ATP content at preischemia and postreperfusion according to graft large-droplet (Ld-MaS, (a)) and small-droplet (Sd-MaS, (b)).
In the present study we have investigated the impact on LT outcomes of donor liver steatosis evaluated using protocol preischemia biopsies and revised according to the Brunt classification. This classification identifies three different types of steatosis, namely, two subtypes of macrovesicular steatosis (Ld-MaS and Sd-MaS) and true microvesicular steatosis [
We have conducted separate analyses for graft survival in HCV+ and HCV- recipients. The main result of our study is that liver donor Sd-MaS is an independent risk factor for graft loss in HCV- patients, but not in HCV+ ones. In particular, graft Sd-MaS was associated with graft loss when considered as either a continuous variable or categorized using a cut-off of >15%.
Although the accuracy of frozen liver sections is debated for steatosis assessment [
To date, only one recently published study by Choi et al. has analyzed the impact of Sd-MaS and Ld-MaS on LT outcomes, finding an association of Sd-MaS with acute and chronic rejection, but not with graft survival [
With regard to the mechanisms through which allograft with relevant Sd-MaS have a poor outcome in recipients with HCV- liver disease, we found that these grafts (a) had low ATP content in the preischemia biopsy, suffering a further significant reduction of ATP after reperfusion; (b) were associated with low donor PaO2 and short length of ICU stay; and (c) when transplanted to HCV- recipients, showed a higher early postoperative serum AST peak, compared to the other grafts. Thus, we hypothesize that donors with relevant Sd-MaS have a preexisting impaired mitochondrial function with low baseline ATP content, failure to recover ATP levels after reoxygenation and increased susceptibility to ischemia-reperfusion injury [
In our present study we did not find a negative impact of Sd-MaS on graft survival and early postoperative AST peak in HCV+ patients. Although we do not have a clear explanation for this latter observation, we should underline the fact that HCV is known to strictly interact with lipid droplets into the hepatocytes, redirecting autophagy by inducing lipid-selective autophagy [
With regard to predictors of graft loss in our HCV+ patients, we found that, as previously reported, severe IRI was associated with cirrhosis due to HCV recurrence [
The definition of Ld-MaS in the present study is concordant with the term macrosteatosis/ macrovesicular steatosis used in the literature; according to several studies, when macrosteatosis occurs in more than 60% of hepatocytes, poor outcomes are observed [
The observed result that donor Anti-HBc positivity was connected with poor graft survivals in HCV- patients is in line with previous studies [
There are some limitations of our study that should be addressed. First of all, this is a monocentric study needing an external validation of our results. The study was performed in a long time frame. However, this possible bias was corrected adding the period of transplant as a covariate in our analyses. Although we performed only one liver biopsy of the left hepatic lobe to assess preischemia steatosis, previous studies have shown minimal steatosis variability between left and right lobe sampling [
In conclusion, using protocol preischemia liver graft biopsies, we observed that the presence of Sd-MaS >15% is associated with lower graft ATP content, severe early hepatocellular damage, and reduced graft survival in HCV-negative patients. These data may play an important role in modifying the organ allocation process, especially nowadays with the spreading of NASH and the reduction of HCV-RNA positive recipients thank to DAAs, but need to be validated in other studies.
Direct-Acting Antivirals
Early allograft dysfunction
Hepatocellular carcinoma
Initial poor graft function
Ischemia/reperfusion injury
Large droplet macrovesicular
Liver transplantation
True microvesicular
Partial pressure of oxygen
Small-droplet macrovesicular.
The clinical data used to support the findings of this study are included within the article in anonymous form in order to protect patient privacy as request by the local ethical committee.
The authors of this manuscript have no conflicts of interest to disclose.
This study was supported by the “Fondazione Onlus Parioli” and the Italian Ministry of Instruction University and Research. The authors dedicate the study to professor Paolo Bianco (1955-2015) for his insights and contribution over the years.