end - stage liver cirrhosis ( eslc ) is a fatal clinical condition and frequently accompanied with mental alteration , ascites , jaundice , coagulopathy , and persistent deterioration of liver function .
once a complication of eslc develops , the 5-year survival rate decreased to low than 20% , and patients should be recommended to take liver transplantation ( lt ) .
advances in transplantation have improved long - term survival rates to more than 70% at 5 years after lt . in the case of life - threatening hepatic failure and donation severe shortage ,
abo - incompatible lt ( abo - i lt ) has been suggested as an optimal option for rescuing life .
recently , some parameters from blood were identified as promising markers for prognosis of patients with diverse diseases . among them ,
the elevated preoperative neutrophil - lymphocyte ratio ( nlr ) is a useful predictor for overall survival rates in colorectal cancer , hepatocellular carcinoma ( hcc ) , or nontumoros diseases . in addition , the patients characterized by thrombocytopenia and declining platelet counts were associated with an ominous prognosis .
demonstrated that the restoration of posttransplant absolute lymphocyte count can be a novel prognostic factor for the recurrence of hepatitis c and hcc .
given this , the study was designed to determine the effect of presurgery blood parameters on outcomes of patients with eslc after abo - i lt .
a total of 84 eslc patients undergoing abo - i lt from the first affiliated hospital , zhejiang university school of medicine between january , 2004 , and december , 2011 , were enrolled in our study .
the ab blood type recipients and o blood type donors were excluded from the study .
the cutoff of neutrophil , lymphocyte count , and platelet were acquired according to their median , respectively .
patients with preoperative sepsis , autoimmune hepatitis , hcc , steroids administration before lt , illicit drug abuse , and loss to follow - up were excluded from our study .
all lt were performed following obtaining informed consent from all patients , and this study was approved by the ethical review board of the first affiliated hospital of the medical school of zhejiang university ( no .
the improved strategy in our center for reducing anti - abo antibodies consisted of rituximab , basiliximab , and intravenous immunoglobulin ( ivig ) .
rare abo - i lt patients received splenectomy were due to the serious hypersplenism which commonly diagnosed by stubborn decreasing of white blood cell , lymphocyte , platelet , and neutrophil .
our immunosuppression protocol following abo - i lt adopted a standard protocol of quadruple regimen consisted of basiliximab , methylprednisolone , tacrolimus , and mycophenolate mofetil ( mmf ) .
the median serum tacrolimus concentration was 8.9  4.3 ng / ml in the high - nlr group , and 9.2  6.5 in the normal nlr group presenting no significant difference between two groups .
our immunosuppression protocol following abo - i lt adopted an standard protocol of quadruple regimen .
methylprednisolone ( initially 1000 mg then tapered and withdraw at 1 month ) , tacrolimus ( initially plasma target level : 1012 ng / ml and titrated down to 810 ng / ml ) , and mmf ( 500 mg twice daily ) were administered for maintaining the immunosuppressive effect after surgery .
furthermore , piperacillin - tazobactam , fluconazole , and ganciclovir were adopted postoperatively as an anti - infection strategy .
patients with hepatitis b virus were intravenously injected with lamivudine and hepatitis b immunoglobulin to prevent the recurrence of hepatitis b after lt .
the quantitative and qualitative variables were presented as mean with standard deviation and frequency , respectively .
fisher 's exact test , independent sample t - test , and pearson 's  test were performed to evaluate the differences in the clinicopathologic factors of abo - i lt patients with high and normal nlrs .
the kaplan  meier method and cox proportional hazard model analysis were used to determine the risk factors for poorer prognosis .
the patient characteristics were valued using univariate analysis first , and then risk factors with p < 0.1 were selected and entered into cox proportional hazard model analysis to estimate their hazard ratio . the software program sas version 9.1 ( sas institute inc .
, cary , nc , usa ) was used for analyzing data , and statistical significance was adopted at p < 0.05 .
a total of 84 eslc patients undergoing abo - i lt from the first affiliated hospital , zhejiang university school of medicine between january , 2004 , and december , 2011 , were enrolled in our study .
the ab blood type recipients and o blood type donors were excluded from the study .
the cutoff of neutrophil , lymphocyte count , and platelet were acquired according to their median , respectively .
patients with preoperative sepsis , autoimmune hepatitis , hcc , steroids administration before lt , illicit drug abuse , and loss to follow - up were excluded from our study .
all lt were performed following obtaining informed consent from all patients , and this study was approved by the ethical review board of the first affiliated hospital of the medical school of zhejiang university ( no .
the improved strategy in our center for reducing anti - abo antibodies consisted of rituximab , basiliximab , and intravenous immunoglobulin ( ivig ) .
rare abo - i lt patients received splenectomy were due to the serious hypersplenism which commonly diagnosed by stubborn decreasing of white blood cell , lymphocyte , platelet , and neutrophil .
our immunosuppression protocol following abo - i lt adopted a standard protocol of quadruple regimen consisted of basiliximab , methylprednisolone , tacrolimus , and mycophenolate mofetil ( mmf ) .
the median serum tacrolimus concentration was 8.9  4.3 ng / ml in the high - nlr group , and 9.2  6.5 in the normal nlr group presenting no significant difference between two groups .
our immunosuppression protocol following abo - i lt adopted an standard protocol of quadruple regimen .
methylprednisolone ( initially 1000 mg then tapered and withdraw at 1 month ) , tacrolimus ( initially plasma target level : 1012 ng / ml and titrated down to 810 ng / ml ) , and mmf ( 500 mg twice daily ) were administered for maintaining the immunosuppressive effect after surgery .
furthermore , piperacillin - tazobactam , fluconazole , and ganciclovir were adopted postoperatively as an anti - infection strategy .
patients with hepatitis b virus were intravenously injected with lamivudine and hepatitis b immunoglobulin to prevent the recurrence of hepatitis b after lt .
the quantitative and qualitative variables were presented as mean with standard deviation and frequency , respectively .
fisher 's exact test , independent sample t - test , and pearson 's  test were performed to evaluate the differences in the clinicopathologic factors of abo - i lt patients with high and normal nlrs .
the kaplan  meier method and cox proportional hazard model analysis were used to determine the risk factors for poorer prognosis .
the patient characteristics were valued using univariate analysis first , and then risk factors with p < 0.1 were selected and entered into cox proportional hazard model analysis to estimate their hazard ratio .
, cary , nc , usa ) was used for analyzing data , and statistical significance was adopted at p < 0.05 .
of the 84 adult recipients who underwent emergency abo - i lt for alf at our hospital , 13 ( 15.5% ) were excluded ( seven recipients had steroids administration before lt , three were loss to follow - up , two were autoimmune hepatitis , and one had drug abuse ) .
the study populations consisted of 47 males and 24 females and the median age at diagnosis was 47.9 years .
of 71 patients , 13 ( 18.3% ) received preoperative artificial liver support , three ( 4.2% ) underwent splenectomy along with lt [ table 1 ] .
the blood type combinations between donors and recipients included the following pairings : a to b , o ; ab to a , b , o ; b to a , o ; whereas ab blood type recipients and o blood type donors were excluded from the study [ table 2 ] .
patient demographics and clinical characteristics blood type combinations between donors and recipients the median follow - up period was 41.2 months and the courses of death during study period included multiple organ failure / sepsis , cerebral hemorrhage , antibody - mediated rejection ( amr ) , neurological complications , and gradual graft failure . among them , sepsis was the main death factor [ figure 1a ] .
of 14 dead patients were due to sepsis , 11 ( 78.6% ) with high nlr and three with normal nlr .
the 1- , 3- , and 5-year overall survival rates of the study population were 78.8% , 68.0% , and 68.0% , respectively .
( a ) suggested that sepsis was the main course of death , specially , in the high neutrophil - lymphocyte ratio group ( p = 0.025 ) , ( b ) the infection complications was more in the high neutrophil - lymphocyte ratio group than in the normal group but presented no statistical significance ( p = 0.056 ) the abnormal renal function was defined by high creatinine ( > 133
we found that the patients with high serum creatinine were respectively 26 in the high - nlr group and seven in the normal nlr group , but lt receptors with pretransplant high serum creatinine did not presented poorer prognosis including survival outcomes and complications .
of all factors , only high nlr had remarkable effect on survival outcomes after abo - i lt and related results were presented in table 3 .
the 1- , 3- , and 5-year overall survival were 94.9% , 80.0% and 80.0% in the normal nlr group respectively , and 59.4% , 55,4% and 55.4% in patients with up - regulated nlr respectively [ p = 0.001 , figure 2a ] .
we also analyzed the effect of elevated nlr on complications and found none correlation between them [ figure 1b ] .
univariate and multivariate analysis of factors affecting overall survival after abo - incompatible liver transplantation kaplan 
meier chart comparing both overall survivals for patients classified according to the neutrophil - lymphocyte ratio ( a ) , neutrophil count ( b ) , and lymphocyte count ( c ) preoperatively .
the curves presented different survival rates of patients with abo - incompatible liver transplantation with different preoperative neutrophil - lymphocyte ratio or neutrophil count , but bot with different lymphocyte count the median counts of neutrophil and lymphocyte were significantly different between the elevated nlr group and the normal nlr group ( p < 0.001 , p = 0.003 respectively ) .
the 1- , 3- and 5-year recipient survival rates were 61.8% , 58.5% and 58.5% , respectively , in the high neutrophil group , and 94.6% , 74.8% and 74.8% , respectively in the low - neutrophil group [ p = 0.016 , figure 2b ] .
however , we found that the 1- , 3- and 5-year overall survival rates were 77.4% , 59.7% and 59.7% in the lymphopenia group , respectively , and 79.9% , 77.1% and 77.1% in the normal - lymphocyte group , respectively [ p = 0.504 , figure 2c ] .
in addition , we further divided patients into a death group and a survival group and found that there were a significant difference in nlr and neutrophil count whereas not in lymphocyte count and white blood cell [ figure 3 ] .
these results suggested that the high - neutrophil count was the main cause for high nlr inducing poorer recipient survival .
in addition , high neutrophil and high nlr presented p < 0.1 in univariate analysis ; these factors were further selected and entered into cox proportional hazard model analysis to estimate their hazard ratio , and only high nlr remains statistical significance [ table 3 ] .
the difference of pretreatment neutrophil - lymphocyte ratio ( a ) , neutrophil count ( b ) , lymphocyte count ( c ) and white blood cell ( d ) , between the survival and death groups in the retrospective cohort .
there were a significant difference in neutrophil - lymphocyte ratio and neutrophil count , whereas not in lymphocyte count and white blood cell
of the 84 adult recipients who underwent emergency abo - i lt for alf at our hospital , 13 ( 15.5% ) were excluded ( seven recipients had steroids administration before lt , three were loss to follow - up , two were autoimmune hepatitis , and one had drug abuse ) .
the study populations consisted of 47 males and 24 females and the median age at diagnosis was 47.9 years .
of 71 patients , 13 ( 18.3% ) received preoperative artificial liver support , three ( 4.2% ) underwent splenectomy along with lt [ table 1 ] .
the blood type combinations between donors and recipients included the following pairings : a to b , o ; ab to a , b , o ; b to a , o ; whereas ab blood type recipients and o blood type donors were excluded from the study [ table 2 ] .
patient demographics and clinical characteristics blood type combinations between donors and recipients the median follow - up period was 41.2 months and the courses of death during study period included multiple organ failure / sepsis , cerebral hemorrhage , antibody - mediated rejection ( amr ) , neurological complications , and gradual graft failure . among them , sepsis was the main death factor [ figure 1a ] .
of 14 dead patients were due to sepsis , 11 ( 78.6% ) with high nlr and three with normal nlr .
the 1- , 3- , and 5-year overall survival rates of the study population were 78.8% , 68.0% , and 68.0% , respectively .
( a ) suggested that sepsis was the main course of death , specially , in the high neutrophil - lymphocyte ratio group ( p = 0.025 ) , ( b ) the infection complications was more in the high neutrophil - lymphocyte ratio group than in the normal group but presented no statistical significance ( p = 0.056 )
the abnormal renal function was defined by high creatinine ( > 133 mol / l ) .
we found that the patients with high serum creatinine were respectively 26 in the high - nlr group and seven in the normal nlr group , but lt receptors with pretransplant high serum creatinine did not presented poorer prognosis including survival outcomes and complications .
of all factors , only high nlr had remarkable effect on survival outcomes after abo - i lt and related results were presented in table 3 .
the 1- , 3- , and 5-year overall survival were 94.9% , 80.0% and 80.0% in the normal nlr group respectively , and 59.4% , 55,4% and 55.4% in patients with up - regulated nlr respectively [ p = 0.001 , figure 2a ] .
we also analyzed the effect of elevated nlr on complications and found none correlation between them [ figure 1b ] .
univariate and multivariate analysis of factors affecting overall survival after abo - incompatible liver transplantation kaplan  meier chart comparing both overall survivals for patients classified according to the neutrophil - lymphocyte ratio ( a ) , neutrophil count ( b ) , and lymphocyte count ( c ) preoperatively .
the curves presented different survival rates of patients with abo - incompatible liver transplantation with different preoperative neutrophil - lymphocyte ratio or neutrophil count , but bot with different lymphocyte count
the median counts of neutrophil and lymphocyte were significantly different between the elevated nlr group and the normal nlr group ( p < 0.001 , p = 0.003 respectively ) .
the 1- , 3- and 5-year recipient survival rates were 61.8% , 58.5% and 58.5% , respectively , in the high neutrophil group , and 94.6% , 74.8% and 74.8% , respectively in the low - neutrophil group [ p = 0.016 , figure 2b ] .
however , we found that the 1- , 3- and 5-year overall survival rates were 77.4% , 59.7% and 59.7% in the lymphopenia group , respectively , and 79.9% , 77.1% and 77.1% in the normal - lymphocyte group , respectively [ p = 0.504 , figure 2c ] .
in addition , we further divided patients into a death group and a survival group and found that there were a significant difference in nlr and neutrophil count whereas not in lymphocyte count and white blood cell [ figure 3 ] .
these results suggested that the high - neutrophil count was the main cause for high nlr inducing poorer recipient survival .
in addition , high neutrophil and high nlr presented p < 0.1 in univariate analysis ; these factors were further selected and entered into cox proportional hazard model analysis to estimate their hazard ratio , and only high nlr remains statistical significance [ table 3 ] .
the difference of pretreatment neutrophil - lymphocyte ratio ( a ) , neutrophil count ( b ) , lymphocyte count ( c ) and white blood cell ( d ) , between the survival and death groups in the retrospective cohort .
there were a significant difference in neutrophil - lymphocyte ratio and neutrophil count , whereas not in lymphocyte count and white blood cell
to date , most of the researchers payed attention to preexisting anti - abo antibody titer that neglects other potential predictors .
moreover , egawa et al . found the preoperative high anti - abo igm did not have any significance in predicting the frequency of amr and 5-year survival rate following abo - i lt .
recently , several studies reported that nlr could predict the long - term outcomes of patients with hcc after lt and even was selected to challenge the milan criteria as a precise predictive marker .
nlr was a miniature of systemic inflammation and easily calculated by routine examine of peripheral blood samples .
our results presented that elevated nlr was significantly associated with poorer both overall survival and graft survival , in our study population .
the reactive neutrophilia and lymphocytopenia were a physiological response to the immune system to a variety of stressful events , so the high preoperative nlr not only showed the presence of immune dysfunction but also the severity of affliction .
the immune dysfunction of patients with eslc undoubtedly promoted postsurgery infection . besides , in high - nlr group , patients presented more serious lymphocytopenia that increases the susceptibility to infection .
furthermore , the sepsis rather than amr was the crucial cause of patients death after abo - i lt in the study and a previously reported literature , which suggested that the increased postoperative infection diseases are the mechanism underlying high nlr influencing survival outcomes of abo - i lt , and the carefully perioperative management for preventing infection is very important . although the accurate mechanism underlying nlr influencing survival outcomes in various diseases was not clear , our data still provided some hint .
we found that high nrl group presented a higher model for end - stage liver disease ( meld ) score comparing with the normal nlr group . in the previously published literature , lt patients with higher meld
score presented poorer survival outcomes , but the cutoff of high meld score was extraordinary different in the different lt cohort . in our previously published data , we found meld score 28 was an independent risk factor . therefore , we added the analysis of meld score 28 predicting prognosis of abo - i lt recipients .
we found that abo - i lt recipients with meld score 28 presented a significant trend of poorer graft survival outcomes ( p = 0.047 , less than meld score 25.7 ) .
in addition , by the cox proportional hazard model analysis , we defined that high meld score could not interfere in nlr as a predictor for abo - i lt recipients .
the combination of plasma exchange pe , graft local infusion ( gli ) , splenectomy , rituximab , and ivig is a standard protocol of reducing anti - abo antibody titer and the incidence of amr .
raut et al . reported that preoperative rituximab could effectively prevented amr irrespective of splenectomy , and not any immunological benefit was obtained due to splenectomy during the initial 8 weeks .
ikegami et al . indicated that the new protocol using pe , rituxamab , and ivig without gli in four cases after abo - i living donor lt seemed to be a safe treatment because gli leaded to various catheter - associated complications .
, respectively reported that amr was highly associated with postoperative rebound elevation of isoagglutinin titer , and high - dose ivig was very effective . in this study , all of the voluntary donor livers come from the accidentally dead people , so we were not sure the blood type pairs of lt before the operation .
the two reasons urged us to make an emerge abo - i lt without pe .
all patients were administered the improved protocol , and there were only two episodes of amr presented in the study .
the low incidence of amr provided a possibility for rituximab totally substituting for pe and highlighted the role of high - dose ivig and subsequent quadruple immunosuppressive scheme involving steroids in treatment and/or prophylaxis of severe amr .
the small sample size is a limitation in this study , the larger sample size and the further investigation for the effect of high nlr and the improved protocol on long - term survival outcomes are needed in future study .
we found that high nlr was the independent risk factor for poorer overall survival after abo - i lt , which might be selected as an index for rearranging the abo - i lt candidates list .
the high neutrophil count rather than lymphopenia contributed to the effect of elevated nlr on postoperative survival outcomes .
this work was supported by national s and t major project ( no . 2012zx10002 - 017 ) , national natural science foundation of china ( 81373160 , 81302074 ) and nsfc for innovative research group ( 81121002 ) and national natural science foundation of zhejiang province ( lq13h160004 ) , scientific plan of medicine care in zhejiang province ( 20147283 ) .
2012zx10002 - 017 ) , national natural science foundation of china ( 81373160 , 81302074 ) and nsfc for innovative research group ( 81121002 ) and national natural science foundation of zhejiang province ( lq13h160004 ) , scientific plan of medicine care in zhejiang province ( 20147283 ) .
shz and lz contributed in the conception of the work , bl and lg , zhzh conducted the study , revised the draft , and others fished the data collection and analysis .
 background : the study was designed to assess the role of preoperative neutrophil , lymphocyte , and neutrophil - lymphocyte ratio ( nlr ) in predicting survival outcomes of abo - incompatible liver transplantation ( lt).materials and methods : we retrospectively collected the demographic and clinical characteristics of 71 patients with end - stage liver cirrhosis following abo - incompatible lt in this study . 
 kaplan  
 meier survival analysis and cox multiple factors regression analysis were performed to determine the independent risk factors from preoperative blood parameters for poor prognosis.results:the 1- , 3- , and 5-year overall survival were 94.9% , 80.0% , and 80.0% in the normal nlr group , respectively , and 59.4% , 55,4% , and 55.4% in patients with up - regulated nlr , respectively ( p = 0.001 ) . 
 furthermore , no significant difference was observed on post - lt complications between normal nlr and high - nlr groups . 
 the high nlr was identified as the only independent prognostic risk factor for recipient survival ( p = 0.015 , 95% confidence interval = 3.573 [ 1.2849.943]).conclusion : the preoperative high nlr could be considered as a convenient and available indicator for selecting abo - incompatible lt candidates . 
INTRODUCTION
MATERIALS AND METHODS
Patients and blood parameters collection
Management for patients following liver transplantation
Statistical analysis
RESULTS
Patient demographics and outcomes
Correlation between blood parameters and outcomes after ABO-incompatible liver transplantation
The role of neutrophil and lymphocyte in neutrophil-lymphocyte ratio
DISCUSSION
CONCLUSION
Financial support and sponsorship
Conflicts of interest
AUTHORS CONTRIBUTION