Fine-needle aspiration biopsy in the monitoring of liver allografts. II. Applications to human liver allografts

Procalcitonin-a new diagnostic tool in complications following liver transplantation

OBJECTIVE

Does procalcitonin (PCT) allow differentiation between infection and rejection following liver transplantation in the case of fever of unknown origin (FUO)?

DESIGN

Open prospective trial.

SETTING

transplant intensive care unit at a university hospital.

PATIENTS

Forty patients after liver transplantation.

INTERVENTIONS

Liver biopsy for diagnosis of rejection, transcutaneous aspiration cytology for monitoring of lymphocyte activation.

MEASUREMENTS

Procalcitonin from EDTA plasma, APACHE II, Sepsis, score (Elbute and Stoner).

RESULTS

Eleven patients suffered an infectious complication resulting in an increase in PCT levels (2.2-41.7 ng/ml). Eleven patients developed a rejection episode; none of these patients showed a rise in PCT levels. The statistical difference between PCT levels in rejection and infection was significant (p<0.05) on the day of diagnosis.

CONCLUSION

PCT allows differentiation between rejection and infection in the case of FUO. Elevation of PCT plasma levels develops early postoperatively due to operation trauma, and, in the case of FUO with no rise in PCT, a rejection may be suspected.

Intrahepatic CD8+ T-lymphocyte response is important for therapy-induced viral clearance in chronic hepatitis B infection

BACKGROUND/AIMS

To determine which immune cells contribute to HBV-clearance during antiviral therapy, we performed a longitudinal analysis of intrahepatic immune cells during interferon-alpha therapy of chronic HBV-patients using the FNAB technique.

METHODS

Twenty chronic HBeAg+-patients were treated with pegylated alpha-interferon combined with lamivudine or placebo for 52 weeks. FNAB and blood specimens were obtained at week 0, 2, 8 and 52. CD4+- and CD8+ T-lymphocytes, CD56+ cells, IFNgamma and granzyme B (GrB) were immunocytochemically quantified.

RESULTS

The relative numbers of CD56+ cells and CD8+ T-lymphocytes were significantly higher in FNAB compared to blood at all time-points. Responders (n=9) exhibited significant increases in intrahepatic CD8+ and CD8+GrB+ lymphocytes, a small elevation in CD8+IFNgamma+ T-lymphocytes, no change in CD4+ T-lymphocytes, and a decrease in intrahepatic CD56+ cells during the first weeks of therapy. In non-responders (n=11) no significant changes in CD4+- and CD8+ T-lymphocytes and an increase in intrahepatic and CD56+ cells were observed during therapy.

CONCLUSIONS

The intrahepatic CD8+ T-lymphocyte, but not the CD4+ T-lymphocyte or NK/NKT-cell response, is important for HBV clearance during interferon-alpha therapy, and the antiviral effect may be mediated by both cytolytic and non-cytolytic mechanisms.

Blockade of vascular adhesion protein-1 inhibits lymphocyte infiltration in rat liver allograft rejection

Vascular adhesion protein-1 (VAP-1) has been shown to mediate lymphocyte adhesion to endothelia at sites of inflammation, but its functional role in vivo has not been tested in any rodent model. Here we report the effects of VAP-1 blockade on rat liver allograft rejection. BN recipients of PVG liver allografts (known to develop acute rejection by day 7) were treated with 2 mg/kg anti-VAP-1 (a new anti-rat VAP-1 mAb 174-5) or isotype-matched irrelevant antibody (NS1) every other day (n = 6/group) and one group with anti-VAP-1 2 mg/kg daily (n = 7). On day 7, samples were collected for transplant aspiration cytology, histology, and immunohistochemistry. Lymphocyte infiltration to the graft was clearly affected by VAP-blockade. The total inflammation, mainly the number of active lymphoid cells, in transplant aspiration cytology was significantly decreased in animals treated with anti-VAP-1 (4.7 +/- 1.0 and 2.4 +/- 1.0 corrected increment units, respectively) compared to control (6.6 +/- 1.0) (P < 0.05). In histology, the intensity of portal inflammation was significantly decreased (P < 0.05). The amount of T cells expressing activation markers diminished. This is the first demonstration in any prolonged in vivo model that VAP-1 plays an important role in lymphocyte infiltration to sites of inflammation, and, in particular, liver allograft rejection.

Monitoring intrahepatic CD8+ T cells by fine-needle aspiration cytology in chronic hepatitis C infection

Infection of the liver with hepatitis C virus (HCV) causes compartmentalization of CD8+ cytotoxic T cells to the site of disease. These cells are thought to be involved in viral clearance during interferon therapy. The repetitive analysis of the intrahepatic immune response is hampered by the difficulty to obtain the intrahepatic T cells. The fine-needle aspiration biopsy (FNAB) technique was evaluated for its use to obtain liver-derived CD8+ T cells in a minimally invasive way. In 26 chronic HCV patients who were evaluated for Peg-interferon and ribavirin combination therapy, pre-treatment FNABs and peripheral blood specimens were obtained simultaneously with liver tissue biopsies, and CD3+ and CD8+ T cells were quantified by immunocytochemistry. The CD8+/CD3+ ratio was significantly higher in the FNABs than in peripheral blood (P < 0.01), and similar to those in portal areas in the tissue biopsies. A significant correlation was observed between numbers of CD3+CD8+ T lymphocytes in the FNABs and the numbers of CD8+ cells in the lobular fields or in the portal tracts of the liver tissue biopsies, but not with CD3+CD8+ T lymphocytes in peripheral blood. Finally, the ratio of CD8+/CD3+ T lymphocytes in FNABs was significantly higher in those patients who responded rapidly to therapy when compared with slow responders at 4 weeks of treatment (P = 0.02). These findings demonstrate that the intrahepatic T-cell composition is reflected in FNABs, and that the FNAB technique can be used for predicting early virological response to therapy of patients chronically infected with HCV.

The intrahepatic immune response during chronic hepatitis B infection can be monitored by the fine-needle aspiration biopsy technique

Frequent analysis of the intrahepatic cellular immune response during chronic hepatitis B infection is not feasible with the liver tissue biopsy technique, due to its risk profile and patient discomfort. We investigated whether the relatively safe and patient-friendly cytological fine-needle aspiration biopsy (FNAB) technique is suited for this purpose. FNABs taken during hepatitis flares in three chronic hepatitis B patients treated with interferon-alpha, showed significant increments of CD8(+)-lymphocytes compared with the FNABs taken before and after the flares. No increments were observed in peripheral blood. The increments of intrahepatic CD8+ lymphocytes detected by the FNAB were related to anti-viral immune reactivity, since they coincided with significant serum hepatitis B virus DNA level reductions and in two of three patients with HBeAg seroconversion. In conclusion, the FNAB technique is suited to investigate the intrahepatic immune response during chronic hepatitis B infection on a frequent basis.

Granzyme expression in fine-needle aspirates from liver allografts is increased during acute rejection

We investigated whether determination in fine-needle aspiration biopsy (FNAB) specimens of cells expressing granzymes (Grs) and Fas ligand would provide a reliable, easy, and quantitative measure of rejection activity in the transplanted liver. Retrospectively, 13 FNAB specimens obtained during clinical acute rejection, 10 FNAB specimens obtained during subclinical rejection, 12 FNAB specimens obtained during cytomegalovirus (CMV) infection, and 26 FNAB specimens obtained in the absence of rejection or infection were included on the study. Cytospin preparations of FNAB and peripheral-blood specimens were immunocytochemically stained for Fas-ligand and Gr, and increments in the liver were calculated by subtracting frequencies of positive cells in blood from those in FNAB specimens. Only sporadically Fas ligand-expressing, but many Gr-expressing, cells were detected in FNAB specimens. Increments in Gr-positive (Gr(+)) cells were significantly greater in FNAB specimens obtained during clinical rejection (median, 70 Gr(+) cells; range, 0 to 312 Gr(+) cells; P = .006) and tended to be greater in FNAB specimens obtained during subclinical rejection (median, 62 Gr(+) cells; range, 5 to 113 Gr(+) cells; P = .09) compared with those obtained in the absence of rejection (median, 16 Gr(+) cells; range, 0 to 103 Gr(+) cells). Increments obtained during clinical or subclinical rejection did not differ from those obtained during CMV infection (median, 27 Gr(+) cells; range, 6 to 212 Gr(+) cells). With the exclusion of specimens obtained during CMV infection, the sensitivity of Gr determination in FNAB specimens for the diagnosis of acute rejection (either clinical or subclinical) was 70%, and specificity, 69%. In FNAB specimens obtained during clinical and subclinical acute rejection episodes after liver transplantation, increased numbers of Gr-expressing cells were present; in the absence of CMV infection, their quantification provides a measure for rejection activity with moderate accuracy.

Procalcitonin in fever of unknown origin after liver transplantation: a variable to differentiate acute rejection from infection

OBJECTIVE

Does procalcitonin (PCT) differentiate between infection and rejection after liver transplantation in patients with fever of unknown origin?

DESIGN

Open prospective trial.

SETTING

Transplant intensive care unit at a university hospital.

PATIENTS

Forty patients after liver transplantation.

INTERVENTIONS

Liver biopsy for the diagnosis of rejection and transcutaneous aspiration cytology for monitoring of lymphocyte activation.

MEASUREMENTS

Procalcitonin from EDTA plasma, Acute Physiology and Chronic Health Evaluation II, and sepsis score.

RESULTS

Eleven patients experienced an infectious complication resulting in an increase in PCT concentrations (2.2-41.7 ng/mL). Eleven patients had a rejection episode; none of these patients showed a rise in PCT concentrations. The statistical difference between PCT concentrations in rejection and infection was significant (p<.05) on the day of diagnosis.

CONCLUSION

PCT allows for differentiation between rejection and infection in patients with fever of unknown origin. Elevation of PCT plasma concentrations develops early postoperatively from operation trauma, and in the case of fever of unknown origin, with no rise in PCT, a rejection may be suspected.

Antiviral and immunomodulatory effects of desferrioxamine in cytomegalovirus-infected rat liver allografts with rejection

BACKGROUND

Cytomegalovirus (CMV) infection is associated with acute and chronic allograft rejection. We have recently shown that rat CMV increases portal inflammation and bile duct destruction in a model of rat liver allograft rejection. Desferrioxamine (DFO), an iron chelator and antioxidant, has recently been demonstrated to have antiviral as well as immunomodulatory effects in vitro. We therefore investigated whether DFO inhibits (a) CMV infection and (b) graft destruction in our rat model.

METHOD

One day after liver transplantation, PVG (RT1c) into BN(RT1n), the rats were infected with rat CMV (RCMV, Maastricht strain; 10(5) plaque-forming units i.p.). The effects of 100 mg/kg body weight and 200 mg/kg body weight DFO were examined.

RESULTS

In the untreated group, the grafts were uniformly RCMV culture-positive. In the group receiving 200 mg/kg DFO, RCMV replication was effectively inhibited. Inflammatory response in the graft, and especially the number of macrophages, was significantly reduced by DFO. Portal inflammation and bile duct destruction were also significantly reduced. In the untreated group, the bile duct epithelial cells were found to be strongly positive for tumor necrosis factor-alpha and this expression was clearly decreased by DFO. In addition, DFO significantly inhibited vascular cell adhesion molecule-1 expression on sinusoidal endothelial cells.

CONCLUSIONS

Our in vivo transplant study strongly supports the inhibitory effects of metal chelators on CMV infection and their possible usefulness in the treatment of CMV-induced pathogenic changes.

Complement membrane attack complex and protectin (CD59) in liver allografts during acute rejection

BACKGROUND/AIMS

The complement system is important in the rejection of xenografts, but very little is known about its activation in the rejection of allografts. Complement lysis is induced by the membrane attack complex (MAC), an aggregate of C5b, C6, C7, C8 and C9 molecules. The main defender against MAC is the CD59 molecule, also called protectin. In this study, the aim was to analyze the possible deposition of MAC and the fate of CD59 on distinct cell populations during liver allograft rejection.

METHODS

Liver allografts were monitored by frequent fine-needle aspiration biopsies (FNAB) to demonstrate the immunoactivation of rejection. To examine MAC and CD59 in the FNAB, in relation to the activation markers of rejection, IL2-receptor, MHC class II and ICAM-1 expression, specific monoclonal antibodies and immunoperoxidase staining were used.

RESULTS

Ten out of 21 consecutive liver transplants underwent a histologically confirmed episode of reversible acute rejection. In the FNAB, a significant increase of the activation markers IL2-receptor, class II and ICAM-1 correlated with the peak of inflammation during the episode. In association with inflammation, a significant deposition of MAC was recorded in neutrophils and lymphocytes infiltrating the graft and in the parenchymal cells. MAC deposition subsided together with the inflammation. A significant decrease in CD59 expression was seen in neutrophils during rejection, but CD59 expression on other inflammatory cells and hepatic tissue cells varied greatly.

CONCLUSIONS

Complement activation was seen in association with acute rejection of liver allografts and it led to MAC assembly on leukocytes and tissue cells. A decrease in CD59 expression was less clear-cut, but it may predispose the cells to complement-mediated elimination.

Early intragraft inflammatory events of liver allografts leading to chronic rejection

In this retrospective study, we have investigated the early intragraft inflammatory events of 12 liver allografts leading to chronic rejection. The cytological findings and clinical follow-up were analyzed in detail. Nine patients underwent at least one typical lymphoid activation of acute rejection, and three of them were treated more than once. Diagnosis of rejection was based on biopsy histology, cytology and liver dysfunction. In addition to the acute rejections, cytological analysis demonstrated in 11 of 12 grafts an unidentified lymphoid episode that differed from that of rejection. These lymphoid responses were associated with viral infections; cytomegalovirus (CMV) infection in 10 of 12 patients, hepatitis C virus (HCV) infection in 2 of 12 patients, 1 combined with CMV, and hepatitis B virus (HBV) infection in 1 patient. Graft dysfunction was still seen at the end of the follow-up. Thus, intragraft inflammation caused either by acute rejection or by viral infections may be involved in the induction of chronic rejection.

The pattern and phenotype of T-cell infiltration associated with human liver allograft rejection

Although transplant biopsy remains the best means for assessing liver allograft dysfunction, the presence and degree of rejection often is difficult to determine by current histologic criteria. The added diagnostic and prognostic value of examining liver allograft biopsy specimens by immunopathologic methods, such as phenotyping inflammatory cell infiltrates, has been inconclusive. To examine the value of assessing the phenotype and location of T-cell infiltrates we compared findings in 20 liver transplant biopsy specimens obtained from patients undergoing allograft rejection with those in 20 biopsy specimens from patients with no evidence of rejection. Serial frozen sections from all biopsies were labeled by immunoperoxidase techniques using monoclonal antibodies to identify cells expressing CD3, CD4, CD8, CD45RA, and CD45RO. As expected, the median of average cell infiltrates was higher in the rejecting versus nonrejecting group for each cell phenotype and region. However, statistical comparisons indicated that only some combinations of cell phenotype and location were significantly greater in the rejecting versus nonrejecting groups. The median number of portal CD3+ T cells per high-power field was increased in the rejecting versus nonrejecting groups (15.15 v 5.00 cells/high-power field; P < .01). This primarily was the result of a significant increase in CD8+ cells (7.15 v 1.55 cells/high-power field; P < .0001). Examination of cells expressing CD45 isoforms also revealed a suggested increase (P < .04) in CD45RO+ "memory" but not in CD45RA "naive" T cells infiltrating portal areas. In lobular areas cell infiltrates of any examined phenotype were not significantly increased in the rejecting versus nonrejecting groups. These findings indicate that during liver allograft rejection the most characteristic changes involve an increase in T cells infiltrating the graft in portal regions and suggest that human liver allograft rejection preferentially involves memory CD8+ T cells directed at portal structures.

Infections in human liver recipients: different patterns early and late after transplantation

The first 49 consecutive patients who underwent orthotopic liver transplantation between 1984 and 1989 in our department were studied with regard to symptomatic and asymptomatic post-transplantation infections. The major infections carrying a risk of fatal outcome are presented. During the first 4 weeks, fungal and bacterial infections predominated, the percentages of patients affected being 27% and 35%, respectively. Eight patients (17%) suffered from bacterial septicemia, which in six cases was due to gram-negative micro-organisms. The bacterial septicemia was often associated with severe ischemic damage to the graft, rejection, or cholangitis. In addition, a concomitant invasive fungal infection supervened in seven out of eight septic patients, further aggravating the patients' condition. Seventeen of the 49 patients (35%) died after transplantation within 3.3 years. Infection was the cause of death in nine patients (18%), with bacterial septicemia and/or fungemia in eight of these. Cytomegalovirus (CMV) disease was the dominant cause of illness after the 1st month. While only 5 of the 49 patients developed CMV disease during the 1st month (10%), as many as 16 of the 40 recipients who survived beyond that time suffered from symptomatic CMV viremia (40%). CMV mismatching, i.e., the donation of a CMV-positive organ to a CMV-seronegative recipient, entailed the highest risk for CMV disease. Pneumocystis carinii pneumonia occurred within 4 months in 10% of the patients. The four liver recipients affected were among the 20 patients not receiving trimethoprim-sulfamethoxazole prophylaxis. None of the 28 patients who received this prophylaxis over a 12-month period developed this complication (P < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Intercellular adhesion molecule 1 (ICAM-1) induction on hepatocytes is an early marker of acute liver allograft rejection

Intercellular adhesion molecule 1 (ICAM-1) induction on hepatocytes was investigated in relation to immune activation of acute liver allograft rejection. Twelve liver recipients undergoing an episode of acute rejection were monitored by frequent fine needle aspiration biopsy (FNAB) study. All episodes were reversible, and the lymphocyte and lymphoid blast predominated with a high peak of inflammation (6.9 +/- 4.0 corrected increment units). The rejections were treated with a high dose of steroids, and the inflammation subsided within 1 week. ICAM-1 was demonstrated from FNAB preparations by a monoclonal antibody and immunoperoxidase staining. ICAM-1 was not detected on the hepatocytes immediately after transplantation but was always seen during rejection. ICAM-1 appeared 1-5 days before the onset of inflammation in the FNAB. The intensity of ICAM-1 expression increased towards the peak of inflammation and subsided thereafter. ICAM-1 induction on hepatocytes appears to be linked with a very early phase of immune activation and can be considered an early marker for acute liver allograft rejection in the FNAB.

Fine-needle aspiration biopsy in the monitoring of liver allografts

The diagnosis of acute liver allograft rejection is difficult, as clinical signs or liver function tests are too unspecific. The diagnosis is mainly based on biopsy histology. However, the liver core biopsy may be associated with complications. The fine-needle aspiration biopsy (FNAB) method, originally developed for the monitoring of renal transplants, is a reliable and atraumatic technique to diagnose acute cellular rejection of liver allografts. FNAB makes it possible to quantity the inflammation associated with rejection, and to monitor the response to anti-rejection therapy. Additional information is received from changes in liver parenchymal cells indicating tissue damage and/or possible hepatotoxic effects of the drugs used. In addition, FNAB may be helpful in differential diagnosis of infections, cholestasis or other complications. A good correlation between FNAB findings of acute liver rejection and histology has been reported. However, histological examination is needed to diagnose chronic rejection. Several liver transplant centres now use FNAB technology as a routine diagnostic tool.

A quantitative analysis of T lymphocyte populations in human liver allografts undergoing rejection: the use of monoclonal antibodies and double immunolabeling

The aim of this study was to quantitate T-cell populations infiltrating portal tracts, bile ducts and hepatic lobules in 82 biopsy specimens from 25 patients after orthotopic liver transplantation. Biopsy specimens taken immediately after revascularization of the graft were used as controls. Patients studied include 18 with initial rejection episodes, 11 with unresolved rejection, five with vanishing bile duct syndrome and eight patients with other forms of liver injury. Quantitation was done in a blinded fashion for the first 20 biopsy specimens. A double immunolabeling technique was used to simultaneously immunolabel bile duct structures (with anti-major histocompatibility complex class II or antikeratins) and lymphoid populations (with anti-CD2, anti-CD4 or anti-CD8). This facilitated the accurate quantitation of intraepithelial lymphocytes within bile ducts. This technique also enabled simultaneous detection of CD4 and CD8 antigens on lymphocytes in portal tracts. The predominant lymphocyte subtype within biliary epithelium during acute and chronic rejection was of the CD2+/CD8+ phenotype. CD8+/CD4+ ratio in bile ducts was approximately 5:1 in acute, unresolved and chronic rejection. In vanishing bile duct syndrome, double immunolabeling enabled the detection of destroyed interlobular bile duct remnants that were not apparent on routine hematoxylin and eosin staining. Attached to some of these structures were CD8+ lymphocytes. Lobular CD8+ cells were not prominent in acute rejection but increased significantly in biopsy specimens from patients with unresolved and chronic rejection. In chronic rejection, a selective increase was seen in these CD8+ cells in centrizonal regions.(ABSTRACT TRUNCATED AT 250 WORDS)