Extracorporeal cellular therapy (ELAD) in severe alcoholic hepatitis: A multinational, prospective, controlled, randomized trial

Severe alcoholic hepatitis (sAH) is associated with a poor prognosis. There is no proven effective treatment for sAH, which is why early transplantation has been increasingly discussed. Hepatoblastoma-derived C3A cells express anti-inflammatory proteins and growth factors and were tested in an extracorporeal cellular therapy (ELAD) study to establish their effect on survival for subjects with sAH. Adults with sAH, bilirubin ≥8 mg/dL, Maddrey's discriminant function ≥ 32, and Model for End-Stage Liver Disease (MELD) score ≤ 35 were randomized to receive standard of care (SOC) only or 3-5 days of continuous ELAD treatment plus SOC. After a minimum follow-up of 91 days, overall survival (OS) was assessed by using a Kaplan-Meier survival analysis. A total of 203 subjects were enrolled (96 ELAD and 107 SOC) at 40 sites worldwide. Comparison of baseline characteristics showed no significant differences between groups and within subgroups. There was no significant difference in serious adverse events between the 2 groups. In an analysis of the intent-to-treat population, there was no difference in OS (51.0% versus 49.5%). The study failed its primary and secondary end point in a population with sAH and with a MELD ranging from 18 to 35 and no upper age limit. In the prespecified analysis of subjects with MELD < 28 (n = 120), ELAD was associated with a trend toward higher OS at 91 days (68.6% versus 53.6%; P = .08). Regression analysis identified high creatinine and international normalized ratio, but not bilirubin, as the MELD components predicting negative outcomes with ELAD. A new trial investigating a potential benefit of ELAD in younger subjects with sufficient renal function and less severe coagulopathy has been initiated. Liver Transplantation 24 380-393 2018 AASLD.

MicroRNA-93 activates c-Met/PI3K/Akt pathway activity in hepatocellular carcinoma by directly inhibiting PTEN and CDKN1A

To assess the role of microRNAs (miR) in hepatocellular carcinoma (HCC), we performed comprehensive microRNA expression profiling using HCC cell lines and identified miR-93 as a novel target associated with HCC. We further verified miR-93 expression levels in advanced HCC tumors (n=47) by a direct PCR assay and found that elevated miR-93 expression level is significantly correlated with poor prognosis. Elevated miR-93 expression significantly stimulated in vitro cell proliferation, migration and invasion, and additionally inhibited apoptosis. We confirmed that miR-93 directly bound with the 3' untranslated regions of the tumor-suppressor genes PTEN and CDKN1A, respectively,and inhibited their expression. As a result of this inhibition, the c-Met/PI3K/Akt pathway activity was enhanced. IHC analysis of HCC tumors showed significant correlation between c-Met protein expression levels and miR-93 expression levels. Knockdown of c-Met inhibited the activation of the c-Met/PI3K/Akt pathway regardless of hepatocyte growth factor (HGF) treatment, and furthermore reduced the expression of miR-93 in these HCC cells. miR-93 also rendered cells to be more sensitive to sorafenib and tivantinib treatment. We concluded that miR-93 stimulated cell proliferation, migration, and invasion through the oncogenic c-Met/PI3K/Akt pathway and also inhibited apoptosis by directly inhibiting PTEN and CDKN1A expression in human HCC.

Abstract 4686: MicroRNA mir-93 activates oncogenic c-Met/PI3K/Akt pathway targeting PTEN in hepatocellular carcinoma

Background; The incidence rate of hepatocellular cellular carcinoma (HCC) has been rapidly increasing globally; however, no effective systemic therapy has been established for advanced HCC after first line therapy with Sorafenib fails. Combining the immediate need for more effective therapy and emerging reports on epigenetic events in HCC, we aimed to identify specific micro RNA (miR) regulating oncogenic pathways in HCC to serve as potential therapeutic targets.

Materials and Methods; We performed initial screening by miR array analysis in 6 HCC cell lines, as well as stage I-IV HCC paraffin-embedded archival tissue (PEAT) specimens (n=47) which were compared to normal livers and liver cirrhosis specimens (n=74). IHC staining analysis of c-Met and miRs expression by qRT-PCR were performed using cell lines and PEAT specimens. The effect on miR levels on recombinant HGF treatment of HCC cells was assessed. We performed functional miR assays by luciferase-vectors with 3′ untranslated sequences (3′UTR) targeted to specific miR binding regions transfected to HCC cells. c-Met/PI3K/Akt pathway analysis was examined using qRT-PCR and western blot analysis. Biological functional activities of miR in HCC were assessed using proliferation, migration, invasion, and 3D sphered colony assays. Chemosensitivity of HCC kinase inhibitors, Sorafenib and Tivantinib on HCC cell lines were examined using a cell viability assay.

Results; We identified that miR-93 was expressed over 10-fold in HCC cell lines compared to normal liver cells via screening by miR array analysis. miR-93 expression was significantly upregulated in HCC PEAT specimens compared to normal and cirrhosis liver specimens (p=0.002). miR-93 expression was shown to have a significant correlation with IHC staining of c-Met protein in HCC PEAT. In vitro studies demonstrated that the HCC cells treated with recombinant HGF (50 μM; 24 hr) induced overexpression of miR-93. Focusing on miR-93 target genes, miR-93 was demonstrated to interfere with the PTEN expression through binding of specific 3′ UTR regions. miR-93 oncogenic effects were shown to regulate phosphorylation of Akt by suppressing PTEN. We demonstrated that miR-93 was silencing tumor-related pathway genes, whereby its function is controlling c-Met/PI3K/Akt signal transduction. It was confirmed that inhibiting miR-93 expression (anti-miR) would suppress proliferation, migration, and invasion of HCC cells. Anti-miR treatment of HCC cell lines significantly enhanced chemosensitivity against kinase inhibitors, Sorafenib (p=0.021) and Tivantinib (p&lt;0.001).

Conclusion: Our results indicated that miR-93 is targeting PTEN involved in tumorigenesis of HCC through the oncogenic c-Met/PI3K/Akt pathway. We demonstrated that anti-miR-93 enhances chemosensitivity against Sorafenib and Tivantinib in HCC. miR-93 is a potential therapeutic target to mitigate chemosensitivity to kinase inhibitors in HCC.

Note: This abstract was not presented at the meeting.

Citation Format: Katsuya Ohta, Hiromitsu Hoshino, Keisuke Hata, Jinhua Wang, Sharon Huang, Vijay Menon, Steven Colquhoun, Dave S. B. Hoon. MicroRNA mir-93 activates oncogenic c-Met/PI3K/Akt pathway targeting PTEN in hepatocellular carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4686. doi:10.1158/1538-7445.AM2014-4686

Increasing age and survival after orthotopic liver transplantation for patients with hepatocellular cancer

BACKGROUND

Orthotopic liver transplantation (OLT) is the gold standard treatment for patients with early hepatocellular carcinoma (HCC). There are concerns about the efficacy of OLT for HCC in older patients, who we hypothesized might have poorer outcomes. Therefore, we sought to examine advanced age and its impact on OLT outcomes.

STUDY DESIGN

The United Network for Organ Sharing database was queried for patients who underwent OLT for HCC from 1987 to 2009. Patients were divided into 3 age groups: 35 to 49 years old, 50 to 64 years old, and 65 years or older, and patient characteristics were compared. Univariate and multivariate analyses were performed to assess the impact of age on OLT outcomes.

RESULTS

Of 10,238 patients with OLT for HCC, 16.5% (n = 1,688) of patients were 35 to 49 years old, 67.8% (n = 6,937) were 35 to 49 years old, and 15.8% (n = 1,613) were 65 years and older. By Kaplan-Meier method, the 50- to 64-year-old age group had the highest overall survival, despite having one of the highest rates of hepatitis C positivity (70%), but this group also had the lowest rate of diabetes mellitus (8.7%). The lowest overall survival was observed in the 65-year or older age group (p < 0.001). Finally, there was no difference in disease-specific survival among the age groups (p = 0.858), and patients aged 65 years and older had the highest rate of death from nonhepatic causes (17.5%).

CONCLUSIONS

Although OS was prolonged in younger patients who underwent OLT for HCC, there was no observed difference in disease-specific survival among the age groups. Our results suggest that carefully selected patients 65 years of age and older can derive equal benefit from OLT for HCC when compared with their younger counterparts.

Primary hepatocellular carcinoma ("hepatoid" carcinoma) of the pancreas: a case report and review of the literature

Key Clinical Message

We present a case of hepatocellular carcinoma located within the pancreas. These tumors occur in the body and tail of the pancreas, with a male predominance, and at a younger age. Tumors with pure hepatocellular histopathology have better survival and recurrence rates and should be offered surgical therapy if possible.

Current surgical management of infected pancreatic necrosis

Infected pancreatic necrosis (IPN) continues to be a challenging problem for the surgeon. We reviewed the experience on a hepatobiliary surgical service with patients who required operative intervention for IPN with emphasis on surgical approach, timing of surgery, and complications. Between 2002 and 2008, 21 patients underwent surgery for IPN. The initial surgical approach in these 21 patients included either direct pancreatic débridement (DPD, n=13) or transgastric débridement using cyst-gastrostomy (CG, n=8). Fifteen patients (71%) required only a single procedure, whereas three (14%) required two procedures and three (14%) required three procedures. The mean time from onset of pancreatitis to operation was 77 days. Patients requiring a single intervention had a longer interval from onset of pancreatitis to surgery compared with those requiring multiple interventions. When comparing CG and DPD groups, there was a longer interval from onset of pancreatitis to débridement, a lower chance of needing multiple débridements, and fewer pancreatic fistulae in the CG group. Overall survival was 95 per cent. Our results demonstrate that CG can be successfully used in select patients with IPN. Patients undergoing CG are less likely to require repeat surgical debridement and to develop pancreatic fistulae compared with patients undergoing DPD.

Current Surgical Management of Infected Pancreatic Necrosis

Infected pancreatic necrosis (IPN) continues to be a challenging problem for the surgeon. We reviewed the experience on a hepatobiliary surgical service with patients who required operative intervention for IPN with emphasis on surgical approach, timing of surgery, and complications. Between 2002 and 2008, 21 patients underwent surgery for IPN. The initial surgical approach in these 21 patients included either direct pancreatic debridement (DPD, n = 13) or transgastric debridement using cyst-gastrostomy (CG, n = 8). Fifteen patients (71%) required only a single procedure, whereas three (14%) required two procedures and three (14%) required three procedures. The mean time from onset of pancreatitis to operation was 77 days. Patients requiring a single intervention had a longer interval from onset of pancreatitis to surgery compared with those requiring multiple interventions. When comparing CG and DPD groups, there was a longer interval from onset of pancreatitis to debridement, a lower chance of needing multiple debridements, and fewer pancreatic fistulae in the CG group. Overall survival was 95 per cent. Our results demonstrate that CG can be successfully used in select patients with IPN. Patients undergoing CG are less likely to require repeat surgical debridement and to develop pancreatic fistulae compared with patients undergoing DPD.

Pancreaticoduodenectomy after neoadjuvant therapy in a Jehovah's witness with locally advanced pancreatic cancer: case report and approach to avoid transfusion

Although the morbidity and mortality rates associated with pancreaticoduodenectomy (PD) have been improving over the past several decades, perioperative transfusions are often needed. Here, we review the preoperative planning and overall management of a Jehovah's Witness patient with locally advanced pancreatic cancer who would not accept blood transfusion. Management of this case is reviewed, along with the relevant literature regarding major surgery in the Jehovah's Witness population. The use of neoadjuvant chemoradiation was used successfully in locally advanced disease, allowing surgical resection. In addition, we outline a cogent strategy using pre-, intra-, and postoperative techniques to minimize blood loss and maintain hemoglobin at acceptable levels thereby preventing the need for transfusion. These strategies, once in place, may be able to reduce transfusions in all patients having major resections for malignancy.

Pancreaticoduodenectomy after Neoadjuvant Therapy in a Jehovah's Witness with Locally Advanced Pancreatic Cancer: Case Report and Approach to Avoid Transfusion

Although the morbidity and mortality rates associated with pancreaticoduodenectomy (PD) have been improving over the past several decades, perioperative transfusions are often needed. Here, we review the preoperative planning and overall management of a Jehovah's Witness patient with locally advanced pancreatic cancer who would not accept blood transfusion. Management of this case is reviewed, along with the relevant literature regarding major surgery in the Jehovah's Witness population. The use of neoadjuvant chemoradiation was used successfully in locally advanced disease, allowing surgical resection. In addition, we outline a cogent strategy using pre-, intra-, and postoperative techniques to minimize blood loss and maintain hemoglobin at acceptable levels thereby preventing the need for transfusion. These strategies, once in place, may be able to reduce transfusions in all patients having major resections for malignancy.

Living donor liver transplantation: histological abnormalities found on liver biopsies of apparently healthy potential donors

OBJECTIVE

With the continued shortage of deceased donor grafts, living donor liver transplantation has become an option for adult liver transplant candidates. In the non-transplant setting, liver biopsy is typically carried out to evaluate clinical or biochemical hepatic dysfunction. In living donor liver transplantation, assessment of histological abnormalities that are undetectable by serological, biochemical and radiological methods might play an important role in donor and recipient outcome.

METHODS

Seventy consecutive liver biopsies carried out as part of our evaluation of potential donor candidates for adult-to-adult or adult-to-child living donor liver transplants were analyzed.

RESULTS

Of the 70 potential donor candidates who underwent liver biopsy for evaluation for living donor liver transplantation, 67% had an unexpected abnormality, of which steatosis was the most common abnormality (38.5%). A variety of other histopathological abnormalities were found including granulomas of unknown etiology (7%), chronic hepatitis (6%) and a microabscess. None of the histological abnormalities had been suspected despite extensive clinical, serological or radiological investigation.

CONCLUSIONS

Among the 70 potential donor candidates for living donor liver transplantation, 34% had unremarkable liver biopsies. The most common abnormality was steatosis (38.5%). These findings suggest that all potential candidates for living donor liver transplants should undergo screening liver biopsies. The precise significance of these changes remains to be determined, including which of these changes are contraindications to liver transplantation. These findings may also have implications in the non-transplant setting as changes ascribed to specific etiologies for liver disease might include changes occurring in apparently healthy individuals.

Sirolimus-induced hyperlipidaemia in liver transplant recipients is not dose-dependent

BACKGROUND

Sirolimus is a potent immunosuppressive medication that acts by inhibiting T-cell proliferation. It has been used in kidney transplantation because of its lack of nephrotoxicity. It is now being investigated in liver transplantation, but there are concerns about safety and long-term side effects such as dyslipidaemia. Hypertriglyceridaemia is a common adverse event seen with sirolimus use, and often does not respond to dose reduction or anti-lipemic drugs.

METHOD

We report six patients who have developed significant hyperlipidaemia while receiving sirolimus, in spite of therapeutic trough levels.

CONCLUSION

All six patients showed either resolution or improvement in lipid levels with discontinuation of sirolimus.

Predictors of survival after In vivo split liver transplantation: analysis of 110 consecutive patients

OBJECTIVE

To determine the factors that influence patient survival after in vivo split liver transplantation (SLT).

SUMMARY BACKGROUND DATA

Split liver transplantation is effective in expanding the donor pool, and its use reduces the number of deaths in patients awaiting orthotopic liver transplantation. Early SLTs were associated with poor outcomes, and acceptance of the technique has been slow. A better understanding of the factors that influence patient and graft survival would be useful in widening the application of SLT.

METHODS

During a 3.5-year period, 55 right and 55 left lateral in vivo split grafts were transplanted in 102 pediatric and adult recipients. The authors' in vivo split technique has been previously described. Median follow-up was 14.5 months. Recipient, donor, and surgical variables were analyzed for their effect on patient survival after SLT.

RESULTS

Overall survival rates of patients who received an SLT were not significantly different from those of patients who received whole organ transplants. Survival of left lateral segment recipients, at median follow-up time, was 76% versus 80% in patients receiving a trisegment. Fifty of 102 patients (49%) were high-risk urgent recipients (United Network for Organ Sharing [UNOS] status 1 and 2A) and 52 (51%) were nonurgent recipients (UNOS status 2B, 3). High-risk recipients had a survival rate significantly lower than that of nonurgent recipients. By univariate comparison, two variables-UNOS status and number of transplants per patient-were significantly associated with an increased risk of death. Preoperative recipient mechanical ventilation, preoperative prothrombin time, donor sodium level, donor length of hospital stay, and warm ischemia time approached significance. The type of graft (right vs. left) did not reduce the survival rate after transplantation. Multivariate logistic regression analysis identified UNOS status and length of donor hospital stay as independent predictors of survival.

CONCLUSIONS

Patient survival of in vivo SLT is not significantly different from that of whole-organ orthotopic liver transplantation. The variables affecting outcome of in vivo SLT are similar to those in whole-organ transplantation. in vivo SLT should be widely applied to expand a severely depleted donor pool.

Orthotopic liver transplantation for hepatitis C: outcome, effect of immunosuppression, and causes of retransplantation during an 8-year single-center experience

OBJECTIVE

To determine the outcome of orthotopic liver transplantation (OLT) for end-stage liver disease caused by hepatitis C virus (HCV).

SUMMARY BACKGROUND DATA

HCV has become the leading cause of cirrhosis and hepatic failure leading to OLT. Recurrent HCV after OLT is associated with significant complications and may lead to graft loss that requires retransplantation (re-OLT). The authors studied the outcome of transplantation for HCV, the effect of primary immunotherapy, and causes of retransplantation.

METHODS

The authors conducted a retrospective review of their experience during an 8-year period (1990-1997), during which 374 patients underwent transplants for HCV (298 [79.6%] received one OLT; 76 [20.4%] required re-OLT). Median follow-up was 2 years (range 0 to 8.3). Immunosuppression was based on cyclosporine in 190 patients and tacrolimus in 132 patients. In a third group of patients, therapy was switched from cyclosporine to tacrolimus or from tacrolimus to cyclosporine (cyclosporine/tacrolimus group).

RESULTS

Overall, 1-, 2-, and 5-year actuarial patient survival rates were 86%, 82%, and 76%, respectively. The 2-year patient survival rate was 81 % in the cyclosporine group, 85% in the tacrolimus group, and 82% in the cyclosporine/tacrolimus group. In patients receiving one OLT, overall 1-, 2-, and 5-year patient survival rates were 85%, 81%, and 75%, respectively. The 2-year patient survival rate was 79% in the cyclosporine group, 84% in the tacrolimus group, and 80% in the cyclosporine/tacrolimus group. The overall graft survival rates were 70%, 65%, and 60% at 1, 2, and 5 years, respectively. The graft survival rate at 2 years was similar under cyclosporine (68.5%), tacrolimus (64%), or cyclosporine/tacrolimus (60%) therapy. Re-OLT was required in 42 (11.2%) patients for graft dysfunction in the initial 30 days after OLT. Other causes for re-OLT included hepatic artery thrombosis in 10 (2.6%), chronic rejection in 8 (2.1%), and recurrent HCV in 13 (3.4%) patients. The overall survival rates after re-OLT were 63% and 58% at 1 and 2 years. The 1-year survival rate after re-OLT was 61 % for graft dysfunction, 50% for chronic rejection, 60% for hepatic artery thrombosis, and 60% for recurrent HCV. At re-OLT, 85.3% of the patients were critically ill (United Network for Organ Sharing [UNOS] status 1); only 14.7% of the patients were UNOS status 2 and 3. In re-OLT for chronic rejection and recurrent HCV, the 1-year survival rate of UNOS 1 patients was 38.4%, compared with 87.5% for UNOS 2 and 3 patients. In patients requiring re-OLT, there was no difference in the 1-year patient survival rate after re-OLT when cyclosporine (60%), tacrolimus (63%), or cyclosporine/tacrolimus (56%) was used for primary therapy. With cyclosporine, three patients (1.5%) required re-OLT for chronic rejection versus one patient (0.7%) with tacrolimus. Re-OLT for recurrent HCV was required in four (3%) and seven (3.6%) patients with tacrolimus and cyclosporine therapy, respectively.

CONCLUSIONS

Orthotopic liver transplantation for HCV is performed with excellent results. There are no distinct advantages to the use of cyclosporine versus tacrolimus immunosuppression when patient and graft survival are considered. Re-OLT is an important option in the treatment of recurrent HCV and should be performed early in the course of recurrent disease. Survival after re-OLT is not distinctively affected by cyclosporine or tacrolimus primary immunotherapy. The incidence of re-OLT for recurrent HCV or chronic rejection is low after either tacrolimus or cyclosporine therapy.

Efficacy and safety of heat exchanger added to venovenous bypass circuit during orthotopic liver transplantation

Hypothermia during orthotopic liver transplantation (OLT) is common despite measures to prevent this complication. We retrospectively analyzed two groups of patients; those managed with (n = 113) or without (n = 109) a heat exchanger (HE) incorporated in the venovenous bypass (VVB) circuit to test the hypothesis that normothermia before liver reperfusion minimizes hypotension during reperfusion and decreases neohepatic transfusion requirements. Use of the HE resulted in significantly warmer patients during reperfusion and at the end of surgery (P < .001). An increase in neohepatic transfusion requirement was observed in patients with HE use: packed red blood cells, 4 +/- 4 versus 3 +/- 3 units; fresh-frozen plasma, 5 +/- 5 versus 4 +/- 4 units; platelets, 8 +/- 8 versus 6 +/- 7 units; and cryoprecipitate, 5 +/- 7 versus 3 +/- 5 units. There was no difference between the two groups in the untoward hemodynamic events during reperfusion of the liver (P = .31). We conclude that during OLT, the use of an HE in a nonheparinized VVB circuit helps maintain normothermia. Our limited experience suggests that its use is safe but does not improve hemodynamic stability during reperfusion or decrease blood loss during the neohepatic period.

Radical resection combined with liver transplantation for foregut tumors

Between February 1984 and July 1992, six adults with advanced pancreatic adenocarcinoma (n = 1), pancreatic neuroendocrine tumor (n = 2), and cholangiocarcinoma (n = 3) underwent radical foregut resections (n = 3) or radical pancreaticoduodenectomy (n = 3) combined with liver transplantation. The major postoperative complications included diarrhea (n = 4), pancreaticojejunostomy leak (n = 3), infection (n = 7), malnutrition (n = 3), refractory ascites (n = 2), and late hepatic artery thrombosis (n = 1). Tumor recurrence occurred in one patient. The actuarial survival for the group is 82 per cent at 1 year and 55 per cent at 2 years. The results demonstrate that radical pancreaticoduodenectomy/foregut resections combined with liver transplantation offer potential surgical cure of malignancies involving these organs. However, the procedure is formidable, with frequent complications.

Diagnosis and treatment of bowel perforation following pediatric orthotopic liver transplantation

OBJECTIVE

Bowel perforation is a frequent cause of mortality after pediatric orthotopic liver transplantation. The aims of this study were to identify the cause of this phenomenon and to examine current methods of treatment.

DESIGN

This is a retrospective analysis of 246 pediatric patients who underwent orthotopic liver transplantation at a large, urban, tertiary care medical center between 1984 and 1992. We examined the frequency of bowel perforations after transplantation and identified predisposing factors and signs. In this series, bowel perforations occurred in 24 of 246 recipients and were common in those who had previous liver-related surgery (22 patients). Clinical signs included fever (13 patients), leukocytosis (14 patients), and free air on abdominal roentgenograms (11 patients).

RESULTS

Perforation occurred at the Roux-en-Y limb in 15 of 24 recipients as well as in the right transverse colon (five patients), terminal ileum (three patients), and duodenum (one patient). The repair was resection and/or primary closure (18 patients), or diversion (six patients). Recurrent perforations (nine patients) could not be attributed to the method of the repair. Perforation-related sepsis was the primary cause of death in 12 patients (50%) and was more common among patients who developed recurrent perforation (seven [78%] of nine patients).

CONCLUSIONS

The occurrence and location of bowel perforation after pediatric orthotopic liver transplantation suggests that the cause is related to bowel injury during difficult hepatectomy. Mortality may be reduced by early second-look operations in high-risk patients.

Natural killer activity of lymphocytes infiltrating human lung cancers following preoperative systemic recombinant interleukin 2

Tumor-infiltrating lymphocytes (TILs) show depressed natural killer (NK) activity compared with peripheral blood lymphocytes (PBLs). To determine if TIL NK function can be reactivated in vivo, 11 patients with tumors metastatic to the lung were treated with systemic recombinant interleukin 2 (rIL-2). Spontaneous TIL NK activity and NK activity after three days' incubation with 100 U/mL of rIL-2 were increased in patients receiving 15,000 U/kg of rIL-2 preoperatively compared with those receiving between 1000 and 10,000 U/kg. Histologically, higher doses of rIL-2 increased the number of intratumoral lymphocytes, the level of peritumoral lymphocytic transferrin, and the expression of HLA-DR. Spontaneous PBL NK activity in patients receiving between 10,000 and 15,000 U/kg of rIL-2 was also increased and was further increased by in vitro culture with rIL-2. Thus, PBL NK activity and TIL NK function in vivo can be augmented with 15,000 U/kg of systemic rIL-2. Both TIL- and PBL-inducible cytotoxicities were further enhanced by in vitro culture with rIL-2.