Short-term changes in lipid and protein metabolism in liver transplants from living-related donors

Serum lipid expression correlates with function and regeneration following living donor liver transplantation

Following living donor liver transplantation (LDLT; and unlike deceased donor liver transplantation [DDLT]), the liver must rapidly regenerate, and sometimes segmental graft dysfunction (SGD) is observed. Hepatic regeneration requires substantial de novo lipid synthesis, and we previously reported that expression of lipid-related genes is dysregulated in LDLT. Here, we compare serum lipid measurements in 41 LDLT recipients and 43 DDLT recipients at baseline and at serial posttransplant time points. In addition, we examined whether serum lipid/apolipoprotein (apo) levels correlate with the degree of liver regeneration (measured using percent volume increase [%VI] at 3 months) or SGD in LDLT recipients. In contrast to DDLT, lipid levels declined early after LDLT but returned to baseline by 30 days. The odds ratio (OR) for achieving robust regeneration (>90 %VI) was 2.53 (95% confidence interval [CI], 1.15-5.52) for every 1 mg/dL increase in serum apoE at 30 days. The OR of SGD for every year increase in donor age was 1.19 (95% CI, 1.02-1.39), and 0.61 for every 1 mg/dL increase in serum high-density lipoprotein cholesterol at 7 days (95% CI, 0.34-1.11). No associations were detected between preoperative serum lipids/apos in LDLT donors and SGD or %VI in recipients. In conclusion, we suggest that initiation of regeneration prevents the liver from participating fully in lipid transport and metabolism. Inability to meet systemic metabolic needs may result in compromised liver function and SGD. Certain serum lipid concentrations correlate with extent of liver regeneration and function.

Short- and long-time effects of pediatric liver transplantation on serum cholesterol and triglyceride levels--the Vienna cohort

Hyperlipidemia is common in patients after LTX. Although immunosuppressive protocols have changed, there are only few data after pediatric LTX. Aim of our study was to evaluate short- and long-time effects of LTX on serum cholesterol and triglycerides in children with different immunosuppressive regimen. We retrospectively analyzed 24 children (seven boys) who underwent LTX since 1987 and were followed for at least one yr at the Medical University of Vienna. Serum lipids, liver function and records of immunosuppressive therapy were evaluated at first referral, shortly before and three, six, nine and 12 months after LTX, and at last visit (mean 6.6 yr after LTX). At first referral, serum lipids were significantly related to underlying disease and age. Following LTX, prevalence of hypercholesterolemia was 25% and of hypertriglyceridemia 90% after the first year. Long-term follow-up showed an overall decrease of serum lipids. Significant decreases in serum triglycerides were directly related to discontinuation of steroids. There was no effect of calcineurin inhibitors. Our study confirms the high prevalence of hyperlipidemia before and after pediatric LTX and suggests a major role of steroid-withdrawal for the control of post-transplant hypertriglyceridemia.

Assessment of Nutritional Status and Prediction of Postoperative Liver Function from Serum Apolioprotein A-1 Levels with Hepatectomy

BACKGROUND

We investigated the usefulness of apolipoprotein A-1 (apoA) as an indicator of nutritional status, and the correlation of the preoperative apoA level with changes in postoperative liver function following hepatectomy.

METHODS

One hundred patients underwent hepatectomy. Serum levels of apoA, prealbumin (prealb), retinol-binding protein (RBP), lectin-cholesterol acyltransferase (LCAT), hyarulonate (HA), indocyanine green dye retention at 15 minutes (ICG), and the receptor index of Tc-GSA scintigraphy (LHL15) were measured at preoperation and on postoperative days (POD) 7 and 14. Partial resection was carried out in 62 cases, segmentectomy in nine cases, and bisegmentectomy in 29 cases. Co-existent liver conditions were normal liver (NL) in 43 cases, chronic hepatitis (CH) in 29 cases, and liver cirrhosis (LC) in 28 cases.

RESULTS

In most cases the serum apoA level had decreased on POD 7, and recovered on POD 14. There were no significant differences in the changes of apoA between the individual operative procedures. Although preoperative apoA had almost the same value in the NL, CH, and LC cases, apoA in LC cases on POD 14 was the lowest of all cases. The apoA level showed significant correlations with prealb, LCAT, and HA on POD 14. All cases were divided into two groups (group N: apoA over 91 mg/dl; group L: apoA under 90 mg/dl) based on the preoperative serum apoA level. On POD 14, the ICG, LHL15, and HA of group L were significantly deteriorated compared with those of group L.

CONCLUSION

The serum level of apoA reflects the changes in hepatic protein synthetic ability after hepatectomy; therefore, it may be possible to estimate recovery of nutritional status after hepatectomy from serum apoA. Moreover, we can predict postoperative deterioration of liver function from the preoperative apoA level.

Serum lipid and lipoprotein alterations represent recovery of liver function after hepatectomy

BACKGROUND

The assessment of liver function during human liver regeneration is necessary to prevent unexpected liver failure and to prepare for further treatment. We selected patients prospectively and measured serum lipid and lipoprotein levels to identify which lipids and lipoproteins could represent recovery of liver function in human liver regeneration.

METHODS

Thirty selected patients who underwent hepatectomy were divided into three groups depending on the serum hyaluronate (HA) level and the type of liver resection.

RESULTS

We found three patterns of lipid and lipoprotein alterations after hepatectomy. Among the lipids and lipoproteins examined, the serum beta-lipoprotein and low-density lipoprotein (LDL) levels were significantly different among the groups at 7 days after hepatectomy. The alteration of the apolipoprotein (Apo) B level was similar to that of LDL. The LDL level was correlated with both beta-lipoprotein and Apo B before hepatectomy (r=0.653 and 0.894, respectively) and at 7 days after hepatectomy (r=0.841 and 0.943, respectively).

CONCLUSION

Serum HA before hepatectomy can reflect postoperative liver function depending on the type of liver resection. Recovery of the beta-lipoprotein and LDL levels can reflect the recovery of liver function in human liver regeneration within the early period in association with the Apo B level.

Assessment of nutritional status in organ transplant: is transthyretin a reliable indicator?

Transthyretin has been proposed as a nutritional index to screen for malnutrition and monitor the metabolic response to dietary intervention. In the presence of inflammation, circulating transthyretin levels drop regardless of optimal caloric intake. In this case, due to its rapid turnover, the pattern of transthyretin, monitored by means of repeated measures, could indicate the metabolic status (catabolism vs. anabolism). The aim of this review is to investigate the possible role of transthyretin as a nutritional parameter in organ transplantation. The literature on nutritional assessment in transplantation was reviewed and all the data regarding circulating transthyretin levels were analyzed. It appears that, on the one hand, the transthyretin level reflects closely dietary manipulations; on the other hand, it is affected by the inflammatory status. Consequently, interpretation could be difficult during the acute phase immediately after the transplant. Moreover, the role of transthyretin in monitoring the hepatic synthetic function in liver transplant is discussed. In conclusion, transthyretin is a reliable indicator of nutritional status in transplant candidates and potentially useful in the post-transplant phase if the inflammatory status is taken into account.

Changes in serum levels of apolipoprotein A-1 as an indicator of protein metabolism after hepatectomy

The clinical significance of serum apolipoprotein A-1 levels as an indicator of hepatic protein synthesis after hepatectomy was investigated. A total of 50 patients who had undergone hepatectomy at our department from 1997 to 1999 were selected for this study. The serum levels of apolipoprotein A-1, indocyanine green dye retention at 15 minutes, lectin-cholesterol acyltransferase, prealbumin, and high-density lipoprotein cholesterol were measured in these patients preoperatively and on postoperative days 7 and 14. The type of hepatic resection conducted was partial resection in 13 cases, subsegmentectomy in 13 cases, segmentectomy in five cases, and bisegmentectomy in 19 cases. All the patients tolerated the operation, and none of the cases had any severe complications, such as liver failure. In most cases, the serum apolipoprotein A-1 levels decreased on postoperative day 7 and recovered by day 14. There were no significant differences in the changes in apolipoprotein A-1 levels between patients with the individual types of operative procedures. The serum apolipoprotein A-1 levels showed significant correlations with the serum high-density lipoprotein cholesterol, lectin-cholesterol acyltransferase and prealbumin levels on postoperative days 7 and 14; however, there was no significant correlation with the indocyanine green retention test. When the cases were divided into three groups according to the serum level of apolipoprotein A-1 on postoperative day 7 (group A: over 81 mg/dl, group B: 61-80 mg/dl, group C: under 60 mg/dl), the serum indocyanine green retention, prealbumin, lectin-cholesterol acyltransferase and high-density lipoprotein cholesterol levels in group C were significantly lower than those in group A on postoperative day 7. On the basis of these results, it is suggested that the pattern of changes in the serum apolipoprotein A-1 levels may be a good indicator of the hepatic protein synthetic ability during the perioperative period after hepatectomy.

Effects of liver transplantation and resection on lipid parameters: a longitudinal study

BACKGROUND

The liver plays a vital role in the production and clearance of a large number of lipoproteins and is an important determinant of the plasma levels of various lipids including cholesterol, as well as apoproteins such as apoprotein (a).

METHODS

To explore the role of the liver in the regulation of lipids and apoprotein concentrations, a serial prospective study measuring lipid parameters and apoprotein (a) levels over 6 months was performed in individuals undergoing hepatic resection for isolated hepatic metastases, transplantation for end-stage liver disease and in individuals undergoing colorectal surgery for malignancy.

RESULTS

In the group with hepatic resection, there was a rapid decrease in total, high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol in the immediate postoperative period. However, these changes could be explained by fasting and surgical intervention as a similar phenomenon was observed in the control subjects. In patients undergoing liver transplantation, total cholesterol decreased over the the immediate postoperative period but had fully recovered by day 40. Apoprotein (a) was low pre-operatively, remained low over the first week but had risen by day 10. Apoprotein (a) at day 40 correlated with the apoprotein (a) level of the donor (r = 0.80, P < 0.01) but not of the recipient's pre-operative level and this correlation persisted 6 months after hepatic transplantation.

CONCLUSIONS

The liver has a large reserve and is able to maintain lipoprotein production and removal despite greater than 50% removal. The major cause of reduced plasma lipid concentrations in the postoperative period relates to other factors such as fasting and handling of the gut during surgery. In liver transplantation, apoprotein (a) levels resemble those of the donor within 2 weeks of organ donation, consistent with the liver being the major site of production of this apoprotein.

Relationship of apolipoproteins AI, B and lipoprotein Lp(a) to hepatic function of liver recipients during the early post-transplant period

To evaluate serum apo AI, apo B, Lp(a) and the ratio of unesterified cholesterol to total cholesterol as markers of hepatic synthetic capacity after orthotopic liver transplantation, serial measurements of these variables were performed on post-transplant days 1, 3, 5, 7, 10 and 14 in 70 patients. Liver function was assessed by a quantitative dynamic test based on the hepatic conversion of lidocaine to monoethylglycinexylidide (MEGX). Patients were divided into two groups on the basis of clinical and laboratory findings, those with evidence (n = 46) and those without evidence (n = 24) of hepatic dysfunction. Apo AI levels fell in both groups to day 5, but then began to increase in the group with good hepatic function, a highly significant (P < 0.001) positive correlation being found with the results of the MEGX test on post-transplant days 7, 10 and 14. The ratio of unesterified cholesterol to total cholesterol rose in both groups from days 1 to 7 and then began to fall in the group without hepatic dysfunction; a highly significant (P < 0.001) negative correlation was observed with the results of the MEGX test on days 10 and 14, Apo B levels rose in both groups from days 1 to 10, with no significant differences between the two groups; no correlation was observed with the results of the MEGX test on any study day.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemical and biophysical alterations of lipoprotein after liver transplantation from a living related donor. A biochemical and proton NMR study

Changes in lipoprotein metabolism after liver transplantation from living related donors were investigated in nine pediatric patients by means of biochemical and proton nuclear magnetic resonance (NMR) analyses of lipoprotein. NMR offers rapid and nondestructive measurement of lipoprotein. The ratio of esterified cholesterol to total cholesterol, expected to be a prognostic indicator after liver transplantation, was low before the operation (0.44) and recovered to over 0.6 at 3 weeks. The half line width of the methylene peak of lipoprotein, as measured by proton NMR, was correlated with the ratio of esterified cholesterol to total cholesterol. It is suggested that proton NMR analysis can provide information about the biophysical changes in lipoprotein associated with liver transplantation.