Radiographic and α-fetoprotein response predict pathologic complete response to immunotherapy plus a TKI in hepatocellular carcinoma: a multicenter study

BACKGROUND

Pathologic complete response (pCR) following preoperative systemic therapy is associated with improved outcomes after subsequent liver transplant/resection in hepatocellular carcinoma (HCC). However, the relationship between radiographic and histopathological response remains unclear.

METHODS

We retrospectively examined patients with initially unresectable HCC who received tyrosine kinase inhibitor (TKI) plus anti-programmed death 1 (PD-1) therapy before undergoing liver resection between March 2019 and September 2021 across 7 hospitals in China. Radiographic response was evaluated using mRECIST. A pCR was defined as no viable tumor cells in resected samples.

RESULTS

We included 35 eligible patients, of whom 15 (42.9%) achieved pCR after systemic therapy. After a median follow-up of 13.2 months, tumors recurred in 8 non-pCR and 1 pCR patient. Before resection, there were 6 complete responses, 24 partial responses, 4 stable disease cases, and 1 progressive disease case, per mRECIST. Predicting pCR by radiographic response yielded an area under the receiver operating characteristic curve (AUC) of 0.727 (95% CI: 0.558-0.902), with an optimal cutoff value of 80% reduction in the enhanced area in MRI (called major radiographic response), which had a 66.7% sensitivity, 85.0% specificity, and a 77.1% diagnostic accuracy. When radiographic response was combined with α-fetoprotein response, the AUC was 0.926 (95% CI: 0.785-0.999); the optimal cutoff value was 0.446, which had a 91.7% sensitivity, 84.6%, specificity, and an 88.0% diagnostic accuracy.

CONCLUSIONS

In patients with unresectable HCC receiving combined TKI/anti-PD 1 therapy, major radiographic response alone or combined with α-fetoprotein response may predict pCR.

Toripalimab combined with lenvatinib and GEMOX is a promising regimen as first-line treatment for advanced intrahepatic cholangiocarcinoma: a single-center, single-arm, phase 2 study

Advanced intrahepatic cholangiocarcinoma (ICC) has a dismal prognosis. Here, we report the efficacy and safety of combining toripalimab, lenvatinib, and gemcitabine plus oxaliplatin (GEMOX) as first-line therapy for advanced ICC. Thirty patients with pathologically confirmed advanced ICC received intravenous gemcitabine (1 g/m²) on Days 1 and 8 and oxaliplatin (85 mg/m²) Q3W for six cycles along with intravenous toripalimab (240 mg) Q3W and oral lenvatinib (8 mg) once daily for one year. The expression of programmed death-ligand 1 (PD-L1) and genetic status was investigated in paraffin-embedded tissues using immunohistochemistry and whole-exome sequencing (WES) analysis. The primary endpoint was the objective response rate (ORR). Secondary outcomes included safety, overall survival (OS), progression-free survival (PFS), disease control rate (DCR) and duration of response (DoR). As of July 1, 2022, the median follow-up time was 23.5 months, and the ORR was 80%. Twenty-three patients achieved partial response, and one achieved complete response. Patients (21/30) with DNA damage response (DDR)-related gene mutations showed a higher ORR, while patients (14/30) with tumor area positivity ≥1 (PD-L1 staining) showed a trend of high ORR, but without significant difference. The median OS, PFS, and DoR were 22.5, 10.2, and 11.0 months, respectively. The DCR was 93.3%. Further, 56.7% of patients experienced manageable grade ≥3 adverse events (AEs), commonly neutropenia (40.0%) and leukocytopenia (23.3%). In conclusion, toripalimab plus lenvatinib and GEMOX are promising first-line regimens for the treatment of advanced ICC. A phase-III, multicenter, double-blinded, randomized study to validate our findings was approved by the National Medical Products Administration (NMPA, No. 2021LP01825).Trial registration Clinical trials: NCT03951597.

Hepatectomy After Conversion Therapy Using Tyrosine Kinase Inhibitors Plus Anti-PD-1 Antibody Therapy for Patients with Unresectable Hepatocellular Carcinoma

BACKGROUND

Combined treatment with tyrosine kinase inhibitors (TKI) plus anti-PD-1 antibodies showed high anti-tumor efficacy and made conversion resection possible for patients with unresectable hepatocellular carcinoma (HCC). However, long-term survival has not been reported.

METHODS

A cohort of consecutive patients who received combined TKI/anti-PD-1 antibodies as first-line treatment for initially unresectable HCC at the authors' hospital between August 2018 and September 2020 was eligible for this study. Patients who were responding to systemic therapy and met the criteria for hepatectomy underwent liver resection with curative intention. The study also investigated the association of clinical factors with successful conversion resection and postoperative recurrence.

RESULTS

The study enrolled 101 patients including 24 patients (23.8 %) who underwent R0 resection a median of 3.9 months (interquartile range: 2.5-5.9 months) after initiation of systemic therapy. Patients with an Eastern cooperative oncology group performance status of 0, fewer intrahepatic tumors, or a radiographic response to systemic therapy were more likely to be able to receive curative resection. After a median follow-up period of 21.5 months, hepatectomy was independently associated with a favorable overall survival (hazard ratio [HR], 0.050; 95 % confidence interval [CI], 0.007-0.365; P = 0.003). For the 24 patients who underwent surgery, the 12-month recurrence-free survival and overall survival rates were respectively 75% and 95.8%. Achieving a pathologic complete response (n = 10) to systemic therapy was associated with a favorable recurrence-free survival after resection, with a trend toward significance (HR, 0.345; 95% CI, 0.067-1.785; P = 0.187).

CONCLUSIONS

Selected patients with initially unresectable HCC can undergo hepatectomy after systemic therapy with combined TKI/anti-PD-1 antibodies. In this study, conversion resection was associated with a favorable prognosis.

Hepatic Arterial Infusion Chemotherapy with Modified FOLFOX as an Alternative Treatment Option in Advanced Hepatocellular Carcinoma Patients with Failed or Unsuitability for Transarterial Chemoembolization

OBJECTIVE

This study aimed to assess the efficacy and safety of hepatic arterial infusion chemotherapy (HAIC) with modified FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) as an alternative treatment option in advanced hepatocellular carcinoma (HCC) patients with failed or unsuitability for transarterial chemoembolization (TACE). MATERIALS AND METHODS: From September 2018 to January 2020, 87 advanced HCC patients who progressed on TACE or were not eligible for TACE received HAIC treatment with modified FOLFOX. The primary endpoint was overall survival (OS) and secondary endpoints included progression-free survival (PFS), tumor response assessed by Response Evaluation Criteria in Solid Tumors 1.1, and adverse events graded according to CTCAE 5.0. Based on prognostic factors determined by multivariate analysis, a nomogram was developed to predict patient survival.

RESULTS

The median OS and PFS were 9.0 months (95%CI 7.6-10.4) and 3.7 months (95%CI 3.1-4.3), respectively. The objective response rate was 13.8%, with a disease control rate of 48.3%. Grade 3 adverse events were observed, such as infection (9.2%), thrombocytopenia (5.7%), hyperbilirubinemia (3.4%), abdominal pain (2.3%) and alanine aminotransferase increase (2.3%). Albumin, AST, and extrahepatic metastasis were incorporated to construct a new nomogram that could stratify patients into three prognostic subgroups, including low-, intermediate-, and high-risk groups, with significant differences in 9-month OS rates (71%, 42% and 6%, respectively; p< 0.001). The nomogram was better than the Okuda, AJCC, and CLIP staging systems for OS prediction.

CONCLUSION

These findings support the feasibility of HAIC with modified FOLFOX as an alternative treatment strategy for advanced HCC when TACE is ineffective or unsuitable.

Development of a Prognostic Scoring System for Hepatocellular Carcinoma Patients With Main Portal Vein Tumor Thrombus Undergoing Conventional Transarterial Chemoembolization: An Analysis of 173 Patients

Background

Patients with hepatocellular carcinoma (HCC) with main portal vein tumor thrombus (mPVTT) have poor prognosis. Promising systemic therapies, such as target therapies, have limited benefits. The purpose of this study is to retrospectively evaluate the benefits of conventional TACE (c-TACE) and to establish a prognostic stratification of HCC patients with mPVTT.

Methods

This is a single center retrospective study conducted over 5 years (duration of performing c-TACE), on consecutive HCC patients with mPVTT receiving c-TACE. Univariable and multivariable analysis were used to explore factors independently associated with overall survival (OS). Based on Cox-regression analysis, prognostic models were developed and internally validated by bootstrap methods. Discrimination and performance were measured by Akaike information criterion, concordance index, and likelihood ratio test.

Results

A total of 173 patients were included. Median OS was 6.0 months (95%CI: 3.92~8.08). The independent variables correlated with survival were largest tumor diameter, tumor number, mPVTT extension, and AFP. In the final model, patients were assigned 2 points if largest tumor diameter ≥8 cm, or tumor number ≥2, 1point if main trunk was complete obstructed, or AFP ≥400 ng/ml. By summing up these points, patients were divided into three risk groups according to the score at the 15rd and 85th percentiles, in which median OS were 18, 7, and 3.5months, respectively (p<0.001). The model shown optimal discrimination, performance, and calibration.

Conclusions

c-TACE could provide survival benefits in HCC patients with mPVTT and the proposed prognostic stratification may help to identify good candidates for the treatment, and those for whom c-TACE may be futile.

Downstaging and Resection of Initially Unresectable Hepatocellular Carcinoma with Tyrosine Kinase Inhibitor and Anti-PD-1 Antibody Combinations

BACKGROUND

Combined therapy with tyrosine kinase inhibitors (TKIs) and anti-PD-1 antibodies has shown high tumor response rates for patients with unresectable hepatocellular carcinoma (HCC). However, using this treatment strategy to convert initially unresectable HCC to resectable HCC was not reported.

METHODS

Consecutive patients with unresectable HCC who received first-line therapy with combined TKI/anti-PD-1 antibodies were analyzed. Tumor response and resectability were evaluated via imaging every 2 months (±2 weeks) using RECIST v1.1. Resectability criteria were (1) R0 resection could be achieved with sufficient remnant liver volume and function; (2) intrahepatic lesions were evaluated as partial responses or stable disease for at least 2 months; (3) no severe or persistent adverse effects occurred; and (4) hepatectomy was not contraindicated.

RESULTS

Sixty-three consecutive patients were enrolled. Of them, 10 (15.9%) underwent R0 resection in 3.2 months (range: 2.4-8.3 months) after the initiation of combination therapy. At baseline, these 10 patients had a median largest tumor diameter of 9.3 cm, 7 had Barcelona Clinic Liver Cancer stage C (vascular invasion) disease, 2 had stage B, and 1 had stage A. Before surgery, 6 patients were evaluated as a partial response, 3 stable disease, and 1 partial response in the intrahepatic lesion but a new metastatic lesion in the right adrenal gland. Six patients (60%) achieved a pathological complete response. One patient died from immune-related adverse effects 2.4 months after hepatectomy. After a median follow-up of 11.2 months (range: 7.8-15.9 months) for other 9 patients, 8 survived without disease recurrence, and 1 experienced tumor recurrence.

CONCLUSIONS

Combination of TKI/anti-PD-1 antibodies is a feasible conversion therapy for patients with unresectable HCC to become resectable. This study represents the largest patient cohort on downstaging role of combinational systemic therapy on TKI and PD-1 antibody for HCC.

Radiological response as a predictor of pathological response to combined tyrosine kinase inhibitor (TKI) and anti-PD-1 antibodies in hepatocellular carcinoma (HCC)

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Background: Pathological complete response (CR) and major pathological response (MPR) are associated with long-term survival after neoadjuvant/conversion surgery of HCC. The relationship between imaging and histopathological evaluations of response to combined TKI plus anti-PD-1 antibody treatment is unclear. Methods: This retrospective analysis included 23 patients with an initial diagnosis of unresectable HCC who underwent resection after combined TKI/anti-PD-1 antibody treatment between March 2019 and December 2020 at Zhongshan Hospital of Fudan University. MRI was performed before and after treatment and objective response rate (ORR; CR or partial response [PR]) was evaluated using RECIST 1.1 and mRECIST by investigator assessment (INV) and independent imaging review (IIR). Histopathological response was evaluated in resected tumor tissue using residual viable tumor (RVT; RVT area/total tumor bed surface area under 100X microscopy). MPR was defined as <10% RVT. The relationship between radiological reduction in tumor size and MPR was investigated using a receiver operating characteristic (ROC) curve. Results: Patients had a median age of 54.0 years, 91% were male and the average pre-treatment tumor diameter was 11.5±4.6 cm. Three had Barcelona Clinic Liver Cancer (BCLC) Stage A disease (China Liver Cancer Stage [CNLC] Ib, n=3), six had BCLC Stage B (CNLC IIa, n=1 and IIb n=5) and 14 had BCLC Stage C (CNLC IIIa, n=10 and IIIb, n=4). Patients received lenvatinib (n=19) or apatinib (n=4) plus anti-PD-1 antibodies (pembrolizumab [n=5], sintilimab [n=5], camrelizumab [n=10], treprizumab [n=2] or nivolumab [n=1]) followed by resection. Radiological responses are summarized in Table. An MPR or pathologic CR was achieved by 52.2% (12/23) and 39.1% (9/23) of patients, respectively. A correlation was observed between radiological responses using RECIST 1.1 and mRECIST and MPR (Fisher’s exact test; P=0.089 and 0.037, respectively). Using RECIST 1.1, the optimum diagnostic cutoff for MPR was a 26% reduction in tumor size, by both INV (area under ROC (AUC)=0.780, 95% CI: 0.580–0.981, sensitivity 83.3%, specificity 72.7%) and IIR (AUC=0.739, 95% CI: 0.527–0.951, sensitivity 75.0%, specificity 72.7%). Using mRECIST, the optimum cutoff for MPR was a 78% reduction in tumor size by INV (AUC=0.746, 95% CI: 0.538–0.954, sensitivity 58.3%, specificity 90.9%) and IIR (AUC=0.742, 95% CI: 0.532–0.953, sensitivity 66.7%, specificity 81.8%). Conclusions: Radiological response showed a degree of correlation with MPR in patients with advanced HCC receiving combined TKI and anti-PD-1 antibody therapy. Therefore, imaging evaluation may be used to predict a pathological response and further guide clinical treatment decisions. Response rates (n=23).[Table: see text]

Organ specific responses to first-line lenvatinib plus anti-PD-1 antibodies in patients with unresectable hepatocellular carcinoma: a retrospective analysis

BACKGROUND

We evaluated organ-specific response rates (OSRRs) to first-line lenvatinib plus anti-PD-1 antibodies in patients with advanced hepatocellular carcinoma (HCC).

METHODS

This retrospective analysis included Chinese patients with unresectable/advanced HCC who received first-line lenvatinib (8 mg/day) plus ≥3 infusions of anti-PD-1 antibodies between October 2018 and May 2020. Tumor and macrovascular tumor thrombi (MVTT) treatment responses were evaluated every 2 months using RECIST v1.1. The overall response rate (ORR)/OSRR was defined as the percentage of patients with a best overall response of complete or partial response (CR or PR).

RESULTS

In total, 60 patients were included in the analysis; 96.7% had measurable intrahepatic lesions, 55% had MVTT and 26.7% had extrahepatic disease. In all 60 patients, the ORR was 33.3%, median progression-free survival was 7.0 months (95% CI, 1.7-12.3) and median overall survival was not reached. The OSRR for MVTT (54.5%) was higher versus intrahepatic tumors (32.8%), extrahepatic lung metastases (37.5%) and lymph node metastases (33.3%). Among 33 patients with intrahepatic tumors and MVTT, 18 had differential responses in each site, including 13 with a better response in MVTT versus intrahepatic lesions. Among 18 patients whose MVTT achieved a radiographic CR or PR, six underwent surgical resection: 4/6 achieved a pathological CR in MVTT and 2/6 in the intrahepatic tumor.

CONCLUSIONS

First-line lenvatinib plus anti-PD-1 antibodies resulted in better tumor responses in MVTT versus intrahepatic lesions. Complete MVTT necrosis may allow downstaging and subsequent eligibility for surgical resection in a proportion of patients with advanced HCC.

Early tumor marker decrease to predict the efficacy of combination therapy with lenvatinib plus anti-PD-1 antibodies in unresectable hepatocellular carcinoma (uHCC)

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Background: Combination therapy with anti-angiogenic agents plus anti-PD-1 antibodies has shown high anti-tumor activity in uHCC. However, predicting the efficacy of this combination therapy remains a challenge. Methods: This study included consecutive patients with uHCC who received lenvatinib (8 mg/d regardless of body weight) and an anti-PD-1 antibody as first-line systemic therapy between Sep 2018 and July 2020, and had at least one imaging evaluation. Tumor response was assessed every 2 months (± 2 week) by the investigators using modified RECIST criteria. Patients were evaluated as having a radiological response (complete or partial response) or non-radiological response (stable disease or progressive disease) at the best overall response evaluation. Serum tumor markers for HCC, including alpha-fetoprotein (AFP) and protein induced by vitamin K absence or antagonist-II (PIVKA-II), were evaluated at baseline and 2-3 weeks after therapy was initiated and their association with radiological response were assessed. Patients with baseline AFP or PIVKA-II between the upper limit of normal and the maximum measuring range of the kit were evaluable for AFP decrease or PIVKA-II decrease. Results: A total of 76 patients were eligible for this study. Baseline AFP ≥400 ng/mL or PIVKA-II ≥400 mAU/mL was not associated with radiological response (P = 0.167 and P = 0.916, respectively). At 2-3 weeks after the initiation of therapy, 51 patients were evaluable for AFP decrease; 78.4% experienced a > 20% AFP decrease and 51.0% experienced a > 50% AFP decrease. Patients with a > 50% AFP decrease had a higher rate of radiological response than those with AFP increase or a ≤50% AFP decrease (73.1% vs 32.0%, P = 0.003). In 57 patients evaluable for PIVKA-II decrease, 50.9% and 35.1% experienced a > 20% and > 50% PIVKA-II decrease, respectively. Patients with a > 50% PIVKA-II decrease had a higher rate of radiological response than those with PIVKA-II increase or a ≤50% PIVKA-II decrease (85.0% vs 29.7%, P < 0.001). Both AFP decrease > 50% and PIVKA-II decrease > 50% predicted radiological response, with an area under receiver operating characteristic curve of 0.706 (95% CI, 0.560-0.852, P = 0.012) and 0.752 (95% CI, 0.621-0.883, P = 0.001), respectively. Furthermore, patients with a > 20% AFP or PIVKA-II increase from baseline had a lower rate of radiological response (0% vs 57.4%, P = 0.043; and 21.7% vs 69.7%, P < 0.001, respectively). Conclusions: A tumor marker decrease was seen in most patients as early as 2-3 weeks after the initiation of the combination therapy. Early on-treatment AFP or PIVKA-II decrease may serve as a predictor for objective response for patients with uHCC receiving combination anti-angiogenic and immune therapy.

Initially unresectable hepatocellular carcinoma treated by combination therapy of tyrosine kinase inhibitor and anti-PD-1 antibody followed by resection

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Background: Combination of tyrosine kinase inhibitor (TKI) and anti-PD-1 antibody showed a high tumor response for advanced hepatocellular carcinoma (HCC). We are aiming to study the effect of combination therapy followed by resection in pts with initially unresectable HCC. Methods: 60 consecutive pts with unresectable or advanced HCC were treated with combination therapy as first-line treatment, including 2 in BCLC-A (China Liver Cancer stage [CNLC]-Ib), and 13 in BCLC-B (CNLC-IIa and IIb), 26 in BCLC-C (vascular invasion, CNLC-IIIa) and 19 in BCLC-C (extrahepatic metastasis, CNLC-IIIb). Tumor response and resectability were evaluated by imaging every 2 months (± 1 week). The criteria of resectability included: (1) R0 resection can be achieved; (2) remnant liver volume ≥ 40%; (3) Child-Pugh score is 5; (4) no contra-indications for hepatectomy. Results: Conversion to resectable HCC was identified in 11 (18.3%) pts after combination therapy. Of them, 2 pts are still under treatment for immune-related adverse events, and 9 underwent hepatectomy as of January 2020. Of the 9 pts, the initial tumor was unresectable because of macro-vascular invasion (n = 6, 1 Vp3, 3 Vp4, 1 hepatic vein, 1 inferior vena cava), extrahepatic metastasis (n = 1, right adrenal gland), tumor nodules ≥ 4 (n = 1) and recurrent HCC within 2 months after first resection (n = 1). The TKIs used were lenvatinib (n = 6) and apatinib (n = 3); anti-PD-1 antibodies used were pembrolizumab (n = 4), sintilimab (n = 3), camrelizumab (n = 1) and nivolumab (n = 1). The median interval between start of combination therapy and resection was 99 days (range, 73–251). The median post-operative hospital stay was 14 days (range, 11–68). The prevalence of post-hepatectomy liver dysfunction (the criteria by ISGLS) is 5 (55.6%) pts, and the post-operative complications (by Clavien–Dindo classification) occurred in 4 (44.4%) pts, including grade I in 1, grade IIIa in 2, and grade V in 1 (died from immune-related adverse events). Tumor response (RECIST v1.1) evaluated before surgery were PR (n = 5), SD (n = 3), and PD (n = 1). Pathological CR (pCR) was found in 5 (55.6%) cases. After a median follow up of 72 days (range, 11–184), tumor recurrence were diagnosed in 1 patient, and mortality without tumor recurrence in 1 patient, the other 7 cases remained tumor-free. Conclusions: This is to date the largest cohort of pts underwent R0 resection after combination therapy for initially un-resectable HCC. The combination of a TKI and anti-PD-1 antibody is feasible as a conversion therapy.

Combination therapy with lenvatinib and anti-PD-1 antibodies for unresectable or advanced hepatocellular carcinoma: A real-world study

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Background: Combination therapy of anti-angiogenic therapy and anti-PD-1 antibody had shown promising anti-tumor effects for advanced hepatocellular carcinoma (HCC) in clinical trials. Here we report the effectiveness and safety of the combination therapy of lenvatinib and anti-PD-1 antibodies in a cohort of unresectable or advanced HCC pts. Methods: From Sep 2018 to Jan 2020, 77 consecutive pts received a combination treatment of lenvatinib and an anti-PD-1 antibody. Lenvatinib was given 8 mg/d regardless of patient body weight and anti-PD-1 antibody was used either q2wk (nivolumab or camrelizumab) or q3wk (pembrolizumab, sintilimab or toripalimab). pts who completed at least one efficacy and safety assessment were eligible for this study. Tumor response were evaluated with abdominal contrast-enhanced MRI/CT and/or chest CT every 2 mo (± 1 wk). Laboratory tests were monitored every 2-3 wk. Results: 59 pts were eligible for this study. Of them, 1 (1.7%) were BCLC stage A, 10 (16.9%) were BCLC stage B, 48 (81.4%) were BCLC stage C (including 20 pts in China Liver Cancer [CNLC] stage IIIa and 28 in CNLC stage IIIb). 43 (72.9%) pts were treated as first-line therapy. The table below shows efficacy results. R0 resection was performed in 6 (10.2%) pts due to tumor regression. By the data cut-off date, 13 pts died, and mOS was not mature. Overall, the combination treatment was well tolerated. 28 (47.5%) pts had at least one ≥ grade 3 treatment-emergent adverse event. 3 (5.1%) pts died from immune-related adverse events, 2 of them died from immune-related adverse events after hepatectomy. Conclusions: The combination of lenvatinib + anti-PD-1 antibody is effective and well-tolerated in pts with HCC as first-line or second-line treatment. It is also noted that initially unresectable HCC may be converted to resectable HCC following this combination treatment. [Table: see text]

A new prediction model for prognosis of patients with intermediate-stage HCC after conventional transarterial chemoembolization: an internally validated study

Purpose: The prognosis of patients with intermediate-stage hepatocellular carcinoma (HCC) treated by conventional TACE (cTACE) is greatly heterogeneous. This study aimed to develop a new survival prediction model to help select patients who would benefit better from cTACE treatment. Methods: We collected data of 848 treatment-naïve patients with BCLC B HCC who received cTACE as first-line therapy. The prognostic model's variables were derived from univariate and multivariate Cox regression analyses. The concordance index (C-statistic) calculated through cross-validation and bootstrap resampling was used for the model selection. The calibration of our final prediction model was also assessed. Results: The model showed a better discrimination ability than Bolondi's BCLC B1-B4 subclassification to predict the prognosis of BCLC B patients (C-statistic, 0.66 vs. 0.60; difference, 0.05, 95% CI, 0.03-0.07). In cross-validation, bootstrap resampling demonstrated that the model maintained sufficiently discriminant (an average of C-statistic, 0.66; 95% CI, 0.65-0.68). The model calibration was accurate in predicting survival of patients matched well with the observed outcomes. On the basis of the improved survival of 18 months or more as the responding patient, the observations of patients in each response category (responder and non-responder) were fair-moderately matched with those predicted by the model (κ=0.40, P<0.001). Conclusions: Based on clinically available features of patient, tumor and liver function, we developed an alternative prediction model with better performance than the Bolondi's substaging system for intermediate HCC patients after cTACE, which could help define the distinct subgroup of BCLC B patients who are suitable for cTACE treatment.

Hepatitis B surface antigen predicts recurrence after radiofrequency ablation in patients with low hepatitis B virus loads

Radiofrequency ablation (RFA) is a first-line option for the treatment of small liver cancers, but the recurrence remains a problem affecting long-term survival. Hepatitis B virus (HBV) activity is associated with the prognosis of hepatocellular carcinoma (HCC). We investigated the significance of hepatitis B surface antigen (HBsAg) in HCC recurrence after curative RFA treatment in HBV-related small HCC.We enrolled 404 HBV-related patients with small HCC (≤3 cm) who underwent curative RFA. We used univariate and multivariate analyses to investigate the baseline levels of HBsAg, in addition to other known risk factors for HCC recurrence, for association with HCC tumor recurrence after curative RFA.The overall 1-, 2-, and 3-year recurrence-free survival (RFS) rates were 75%, 50%, and 34%, respectively. The median recurrence-free time was 25 months. The level of HBsAg was an independent risk factor for recurrence in patients with lower HBV-DNA levels. In hepatitis Be antigen (HBeAg)-negative patients, the 1-, 2-, and 3-year RFS rates were 79%, 64%, and 44%, respectively, for that with low HBsAg levels, compared with 73%, 50%, and 37%, respectively, for that with high HBsAg levels (P = .039).HBsAg might serve as a valuable marker to evaluate the risk of HCC recurrence in HBeAg-negative patients with low HBV viral load.

High platelet counts increase metastatic risk in huge hepatocellular carcinoma undergoing transarterial chemoembolization

AIM

Accumulating evidence suggests platelets play critical roles in tumor metastasis. Moreover, the role of platelets in metastasis is partially correlated with inflammation. However, evidence regarding the contribution of platelets to hepatocellular carcinoma (HCC) metastasis is lacking. This study investigated the association between platelets and metastatic risk in HCC.

METHODS

We used huge HCC (diameter over 10 cm), a tumor subgroup with a strong inflammatory background, as a model to evaluate the potential predictive role of platelets and platelet-related biomarkers for metastasis in HCC patients undergoing transarterial chemoembolization. A logistic regression model was used to analyze risk factors for metastasis.

RESULTS

Patients with huge HCC (n = 178) were enrolled, and 24.7% (44/178) of patients had remote metastases after treatment. Univariate analyses showed high platelet counts (P = 0.012), pretreatment platelet-to-lymphocyte ratios (pre-PLR) of 100 or more (P = 0.018) and post-PLR of 100 or more (P = 0.013) were potential risk factors for metastasis. Furthermore, multivariate analyses showed high platelet counts (odds ratio, 2.18; 95% confidence interval, 1.074-4.443; P = 0.031) and platelet-related biomarkers were independent risk factors for HCC metastasis. Particularly, the risk of metastasis in patients with high post-PLR values was significantly greater than patients with low post-PLR values. For tumor response and survival, patients with high platelet counts had faster disease progression (P = 0.002) and worse survival (P < 0.0001).

CONCLUSION

High platelet counts increase the extrahepatic metastasis risk of huge HCC undergoing chemoembolization, which supply clinical verification of the association between high platelet counts and HCC metastasis.

Oxaliplatin and 5-fluorouracil hepatic infusion with lipiodolized chemoembolization in large hepatocellular carcinoma

AIM: To investigate transarterial chemoembolization (TACE) with hepatic infusion of oxaliplatin and 5-fluorouracil and Lipiodol chemoembolization in large hepatocellular carcinoma (HCC).

METHODS: In this retrospective study, 132 patients with unresectable HCCs larger than 10 cm were treated with hepatic infusion of oxaliplatin and 5-fluorouracil followed by Lipiodol chemoembolization. The primary endpoint was overall survival (OS). Sixteen-week disease-control rate, time to progression (TTP), and major complications were also studied. Univariate and multivariate analyses were performed to identify prognostic factors affecting OS and TTP.

RESULTS: A total of 319 procedures were performed in the 132 patients. Eleven (8.3%) patients received radical resection following TACE treatment (median time to initial TACE 4.3 ± 2.3 mo). The median OS and TTP were 10.3 and 3.0 mo respectively, with a 50.0% 16-wk disease-control rate. Major complications were encountered in 6.0% (8/132) of patients following TACE and included serious jaundice in 1.5% (2/132) patients, aleukia in 1.5% (2/132), and hepatic failure in 3.0% (4/132). One patient died within one month due to serious hepatic failure and severe sepsis after receiving the second TACE. The risk factor associated with TTP was baseline alpha-fetoprotein level, and vascular invasion was an independent factor related to OS.

CONCLUSION: Hepatic infusion of oxaliplatin and 5-fluorouracil followed by lipiodolized-chemoembolization is a safe and promising treatment for patients with HCCs larger than 10 cm in diameter.

Sex-determination gene SRY potentially associates with poor prognosis but not sex bias in hepatocellular carcinoma

BACKGROUND

Gender disparity is well known in hepatocellular carcinoma (HCC). SRY is a critical sex-determination gene involved in embryonic development.

AIM

The potential relevance of SRY to HCC progression was evaluated.

METHODS

SRY expression in HCC cell lines and tissues was evaluated. Invasion and wound healing assays were used to evaluate the role of SRY in HCC cell migration. The prognostic value of SRY for HCC patient survival was evaluated.

RESULTS

SRY was highly expressed in HCC cell lines and tumor tissues. Downregulation of SRY expression decreased migration and invasion potential of HCC cells. High SRY levels correlated with poor HCC patient survival. Additionally, neither spatial position nor expression intensity of SRY was correlated with HCC gender disparity.

CONCLUSIONS

High levels of SRY expression correlated with cancer progression and poor HCC patient survival. However, high SRY levels are not significantly correlated with HCC sex bias.

Goosecoid promotes the metastasis of hepatocellular carcinoma by modulating the epithelial-mesenchymal transition

The homeobox gene, goosecoid (GSC), is a transcription factor that participates in cell migration during embryonic development. Because cell migration during development has characteristics similar to cell invasion during metastasis, we evaluated the potential role of GSC in the metastasis of hepatocellular carcinoma (HCC). GSC expression in HCC cell lines and tissues was evaluated, and its effects on the migration potential of HCC cells were determined by GSC knock-down and overexpression methods. In addition, the prognostic role of GSC expression in the metastasis of cancer cells in HCC patients was determined. Our data showed that GSC was highly expressed in several HCC cell lines, particularly in a highly metastatic HCC cell line. Overexpression of GSC promoted cell migration and invasion of HCC cells in vitro. Gain-of-function induced the epithelial-mesenchymal transition but not collective cell migration, whereas loss-of-function induced the reverse change. High-level expression of GSC correlated closely with poor survival and lung metastasis in HCC patients; lung metastases showed more upregulated GSC expression than the primary tumor. We conclude that GSC promotes metastasis of HCC potentially through initiating the epithelial-mesenchymal transition. GSC is also a prognostic factor for poor survival and metastasis of HCC, which suggests its potential as a therapeutic target for metastatic HCC.

Prognostic significance of the neutrophil-to-lymphocyte ratio in primary liver cancer: a meta-analysis

The neutrophil-to-lymphocyte ratio (NLR) is a useful biomarker that reflects systemic inflammation responses. However, the prognostic value of the NLR in patients with primary liver cancer (PLC) remains controversial. We performed a meta-analysis of 26 studies (comprising 4,461 patients) to evaluate the association between the pre-treatment NLR and clinical outcomes of overall survival (OS) and disease-free survival (DFS) in patients with PLC. The correlation between NLR and tumor characteristics or other inflammation-related parameters was also assessed. Data were synthesized using the random-effects model of DerSimonian and Laird, and the hazard ratio (HR) or odds ratio (OR) with 95% confidence interval (CI) was used to estimate effect size. Our analysis indicated that a high NLR predicted poor OS (HR, 2.102; 95% CI: 1.741-2.538) and DFS (HR, 2.474; 95% CI: 1.855-3.300) for PLC. A high NLR was associated with the presence of tumor vascular invasion (OR: 1.889, 95% CI: 1.487-2.400; p<0.001) and an elevated alpha-fetoprotein level (OR: 1.536; 95% CI: 1.152-2.048; p = 0.003). Thus, we conclude that a high NLR indicates a poor prognosis for patients with PLC and may also be predictive for PLC invasion and metastasis. Subgroup analysis suggested that the predictive role of NLR in cholangiocarcinoma is limited, and a further large study to confirm these findings is warranted.

[Effect of transcatheter arterial chemoembolization on HBV DNA level in primary liver cancer patients]

BACKGROUND AND OBJECTIVE

Systemic chemotherapy would suppress the immune system and cause reactivation of hepatitis B virus (HBV) in the tumor patients with HBV infection, which seriously affect the prognosis. Our study was to investigate the effect of transcatheter arterial chemoembolization (TACE) on HBV DNA level in primary liver cancer patients, and explore related factors.

METHODS

Clinical data of 162 patients with primary liver cancer who underwent TACE from December 2004 to July 2008 were analyzed. All patients' HBV DNA level, alpha-fetoprotein (AFP) and liver function before and after TACE were evaluated. Correlation of HBV DNA alteration to AFP was analyzed.

RESULTS

The positive rate of HBV DNA was decreased significantly after TACE (55.6% vs. 71.6%, P<0.01). HBV DNA level was inclined to decrease after TACE in the patients with HBV DNA of > or =1 x 10(5)/mL (odds ratio = 2.7, P<0.01). The decrease of HBV DNA was also related with the decrease of AFP level (odds ratio = 2.6,P<0.05).

CONCLUSION

TACE can decrease HBV DNA level in primary liver cancer patients, especially for those with preoperative HBV DNA level of > or =1 x 10(5)/mL and those with postoperative AFP decline.

[Prognosis and risk factors for recurrence of small liver cancer after a single session of percutaneous radiofrequency ablation]

BACKGROUND & OBJECTIVE

As a new technique of local therapy for liver cancer, radiofrequency ablation (RFA) was widely used these years in China. This study was to evaluate the treatment efficacy of RFA on primary liver cancer (PLC), identify the risk factors of recurrence, and determine the indications of RFA for PLC.

METHODS

Records of 94 primary small liver cancer patients underwent a single session of percutaneous RFA in Liver Cancer Institute/Zhongshan Hospital from Jan. 2001 to Dec. 2003 were reviewed retrospectively. Data analyses were performed using SPSS for windows Ver. 11.5 software.

RESULTS

With a median follow-up of 16 months affer RFA treatment, the cumulative survival rate of 94 patients was 85.5% at 1 year, and 75.6% at 2 years. The cumulative recurrence-free survival rate was 31.3% at 1 year, and 10.4% at 2 years. The total recurrence rate was 66.0% (62/94). Log-rank test revealed that tumor with diameter of >3 cm (P< 0.05), proximity to intrahepatic vessels (P < 0.01), and subcapsular location (P< 0.05) were related to tumor recurrence,while gender, Child-pugh class, alpha fetoprotein (AFP) concentration, and combination therapy with percutaneous ethanol injection were not related to tumor recurrence. Cox regression analysis indicated that tumor proximity to intrahepatic vessels (95%CI, 2.102-7.899; P=0.000), and subcapsular location (95%CI, 1.672-6.289; P=0.001)were associated independently with recurrence after RFA treatment. Severe complications occurred in 2 cases (2.1%), including 1 case of bile duct hemorrhage, 1 case of sub-diaphragm effusion. No RFA related death and other severe complications occurred.

CONCLUSIONS

RFA appears to be a safe treatment for liver cancer. Patients with tumor diameter of <or= 3 cm, no proximity to intrahepatic vessels, and subcapsular location may be the most suitable candidates for RFA.

[Prospective randomized trial of RFA and chemotherapy for unresectable small hepatocellular carcinoma]

OBJECTIVE

To study the clinical safety and effect on local recurrence in unresectable small hepatocellular carcinoma treated by radiofrequency ablation (RFA) with and without chemotherapy through a prospective randomized trial.

METHODS

Thirty-eight unresectable small hepatocellular carcinoma patients with diameter </= 3 cm were selected, of which 27 patients have been followed up for 1 year. Through a prospective randomized trial, 12 patients were in the RFA group and 15 patients in the RFA combined with systemic chemotherapy group. RFA was given image-guided. The regimen of systemic chemotherapy: EADM 50 mg on day 1, 3; CDDP 40 mg on day 1, 3 and FUDR 500 mg on day 1, 2, 3. After RFA treatment, liver function, WBC count and complications were observed on day 1, 4, 7; CT scan was performed in 1, 6, 12 months. The safety and local recurrence were analyzed.

RESULTS

There was no local recurrence of the tumor in the two groups 1 month after RFA treatment. The 6- and 12-month local recurrence rates were significantly lower in the combined group than that in RFA group alone (P < 0.01). There were no severe complications in the two groups, and nor was there any significant difference in liver function and WBC count.

CONCLUSION

RFA combined with systemic chemotherapy is safe, and it can reduce the local recurrence of unresectable small hepatocellular carcinoma </= 3 cm in diameter.

Prevention of hepatocellular carcinoma in mice by IL-2 and B7-1 genes co-transfected liver cancer cell vaccines

AIM: To study the immunoprotective effect of liver cancer vaccine with co-transfected IL-2 and B7-1 genes on hepatocarcinogenesis in mice.

METHODS: The murine liver cancer cell line Hepal-6 was transfected with IL-2 and/or B7-1 gene via recombinant adenoviral vectors and the liver cancer vaccines were prepared. C57BL/6 mice were immunized with these vaccines and challenged with the parental Hepal-6 cells afterwards. The immunoprotection was investigated and the reactive T cell line was assayed.

RESULTS: The immunoprotection of the tumor vaccine was demonstrated. The effect of IL-2 and B7-1 genes co-transfected Hepal-6 liver cancer vaccine (Hep6-IL2/B7 vaccine) on the onset of tumor formation was the strongest. When attacked with wild Hepal-6 cells, the median survival period of the mice immunized with Hep6-IL2/B7 vaccine was the longest (68 d, χ² = 7.70-11.69, P < 0.05) and the implanted tumor was the smallest (z = 3.20-44.10, P < 0.05). The effect of single IL-2 or B7-1 gene-transfected vaccine was next to the IL2/B7 gene co-transfected group, and the mean survival periods were 59 and 54 d, respectively. The mean survival periods of wild or enhanced green fluorescence protein gene modified vaccine immunized group were 51 and 48 d, respectively. The mice in control group all died within 38 d and the implanted tumor was the largest (z = 3.20-40.21, P < 0.05). The cellular immunofunction test and cytotoxicity study showed that the natural killer (NK) cell, lymphokine activated killer (LAK) cell and cytotoxic T lymphocyte (CTL) activities were significantly increased in mice immunized with the Hep6-IL2/B7 vaccine, (29.5% ± 2.5%, 65.0% ± 2.9%, 83.1% ± 1.5% respectively, compared with other groups, P < 0.05).

CONCLUSION: The Hep6-IL2/B7 liver cancer vaccines can induce the mice to produce activated and specific CTL against the parental tumor cells, and demonstrate stronger effect on the hepatocarcinogenesis than single gene modified or the regular tumor vaccine. Therefore, the vaccines may become a novel potential therapy for recurrence and metastasis of HCC.

Molecular regulation of genes encoding xenobiotic-metabolizing enzymes: mechanisms involving endogenous factors

It is widely recognized that xenobiotic-metabolizing enzymes play a fundamental role in the basic processes of carcinogenesis and toxicity on one hand, and chemoprevention and drug efficacy on the other. Realization that different factors can profoundly affect the expression of these enzymes at the genome level has resulted in an enhanced appreciation of the importance these genes play in our modern industrialized age. There continues to be rapid proliferation of studies addressing the molecular regulation of these genes. The discovery of common signal transduction pathways and transcription factors that dictate tissue and developmental-specific expression, as well as variation in expression within a given tissue, suggest that there may be significant interaction among these various regulatory systems. This report is a summary of a symposium that was part of the Structure, Function and Regulation of Cytochromes P450 and Xenobiotic Metabolizing Enzymes satellite meeting of the 2000 joint meeting of the American Society for Biochemistry and Molecular Biology, the American Society for Pharmacology and Experimental Therapeutics, the French Pharmacological Society, and the Pharmacological Society of Canada held in Boston, Massachusetts. This symposium brought together several speakers who addressed specific receptor-mediated signal transduction pathways involved in the regulation of xenobiotic-metabolizing enzymes, as well as other molecular mechanisms whereby endogenous factors are involved in controlling tissue- and developmental-specific expression.

Maximal aryl hydrocarbon receptor activity depends on an interaction with the retinoblastoma protein

The aryl hydrocarbon receptor (AhR) belongs to the basic helix-loop-helix/periodicity/AhR nuclear translocator/simple-minded (Per-Arnt-Sim) family of transcription factors that regulate critical functions during development and tissue homeostasis. Within this family, the AhR is the only member conditionally activated in response to ligand binding, typified by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). We recently demonstrated that the AhR interacts with the retinoblastoma protein (pRb). This report presents evidence that a LXCXE motif in the AhR protein confers pRb binding, which is necessary for maximal TCDD induced G(1) arrest in rat 5L hepatoma cells. The data support a mechanism whereby pRb seems to regulate G(1) cell cycle progression distinct from the direct repression of E2F-mediated transcription. Furthermore, the results indicate that the AhR-pRb interaction regulates TCDD induction of CYP1A1, suggesting that pRb may be a general AhR coactivator.

Insulin-like growth factor I is a dual effector of multiple myeloma cell growth

Multiple myeloma (MM) is an invariably fatal disease that accounts for approximately 1% to 2% of all human cancers. Surprisingly little is known about the cellular pathways contributing to growth of these tumors. Although the cytokine interleukin-6 has been suggested to be the major stimulus for myeloma cell growth, the role of a second potential growth factor, insulin-like growth factor I (IGF-I), has been less clearly defined. The IGF-I signaling cascade in 8 MM cell lines was examined. In 7 of these, the IGF-I receptor (IGF-IR) was expressed and autophosphorylated in response to ligand. Downstream of IGF-IR, insulin receptor substrate 1 was phosphorylated, leading to the activation of phosphatidylinositol-3'-kinase (PI-3K). PI-3K, in turn, regulated 2 distinct pathways. The first included Akt and Bad, leading to an inhibition of apoptosis; the second included the mitogen-activated protein kinase (MAPK), resulting in proliferation. Biologic relevance of this pathway was demonstrated because in vitro IGF-I induced both an antiapoptotic and a proliferative effect. Importantly, in vivo administration of IGF-I in SCID mice inoculated with the OPM-2 line led to approximately twice the growth rate of tumor cells as in controls. These results suggest that IGF-I activates at least 2 pathways effecting myeloma cell growth and contributes significantly to expansion of these cells in vivo. (Blood. 2000;96:2856-2861)

Expression of PTEN in PTEN-deficient multiple myeloma cells abolishes tumor growth in vivo

Biochemical abnormalities associated with the development of multiple myeloma have been difficult to define especially in terms of demonstrating an in vivo effect of suspected lesions. Herein, we have identified such a defect associated with lack of expression of PTEN, a cellular phosphatase involved in the regulation of phosphatidylinositol phosphates (PIP's). In myeloma cells, PIP's are required for phosphorylation of Akt, a key event leading to inhibition of apoptosis. Loss of PTEN results in a failure to de-phosphorylate PIP's and a corresponding increase in Akt phosphorylation. OPM-2 cells lacking PTEN expression have the highest level of Akt phosphorylation of eight lines examined. Loss of PTEN was found to be associated with a 630 bp deletion corresponding to amino acids 56 - 267. Ectopic expression of wild type PTEN in OPM-2 cells inhibited Akt phosphorylation which was correlated with an increase in apoptosis. The in vivo relevance of loss of PTEN expression was demonstrated by injecting control and wild type PTEN transfected OPM-2 cells into SCID mice. Tumors arose at an incidence of 100% in controls, but only 50% (and of smaller size and longer latency) in low PTEN expressing clones. Importantly, clones expressing high levels of PTEN failed to produce tumors even at five times the latency period of controls. These results demonstrate that PTEN deletion/mutation is responsible for in vivo growth of this tumor and suggests that PTEN regulation may play an important role in tumor development in a subset of multiple myeloma patients. Oncogene (2000) 19, 4091 - 4095

A direct interaction between the aryl hydrocarbon receptor and retinoblastoma protein. Linking dioxin signaling to the cell cycle

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor in eukaryotic cells that alters gene expression in response to the environmental contaminant 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD). In 5L hepatoma cells, TCDD induces a G1 cell cycle arrest through a mechanism that involves the AhR. The retinoblastoma tumor suppressor protein (pRb) controls cell cycle progression through G1 in addition to promoting differentiation. We examined whether the human AhR or its dimerization partner, the AhR nuclear translocator, interacts with pRb as a basis of the TCDD-induced cell cycle arrest. In vivo and in vitro assays reveal a direct interaction between pRb and the AhR but not the AhR nuclear translocator protein. Binding between the AhR and pRb occurs through two distinct regions in the AhR. A high affinity site lies within the N-terminal 364 amino acids of the AhR, whereas a lower affinity binding region colocalizes with the glutamine-rich transactivation domain of the receptor. AhR ligand binding is not required for the pRb interaction per se, although immunoprecipitation experiments in 5L cells reveal that pRb associates preferentially with the liganded AhR, consistent with a requirement for ligand-induced nuclear translocation. These observations provide a mechanistic insight into AhR-mediated cell cycle arrest and a new perspective on TCDD-induced toxicity.

Development of a non-radioactive DNA probe and in situ hybridization for detection of Anaplasma marginale in ticks and cattle

A non-radioactive DNA probe was developed for detection of Anaplasma marginale in ticks and cattle. The probe was labeled with digoxigenin 11-dUTP by polymerase chain reaction. The probe was tested on bovine blood and was found to be a sensitive and specific detection method for A. marginale in cattle. The DNA probe was then adapted for in situ hybridization (ISH) of A. marginale in Dermacentor andersoni and D. variabilis ticks infected either as nymphs or adults. One-half of each tick was studied with ISH while the other half was examined with light and electron microscopy. In male ticks infected as adults, tick gut cells first became infected with A. marginale while ticks fed on an infected calf, and they remained infected as they transmission fed on a second, susceptible calf. At the onset of transmission feeding, salivary glands became infected with A. marginale. During transmission feeding infection was also observed in interstitial, reproductive, skeletal muscle, fat body and Malpighian tubule tissue, resulting in a generalized A. marginale infection. When adult ticks that acquired infection as nymphs were examined with ISH and microscopy, gut tissues of both D. andersoni and D. variabilis became infected with A. marginale. However, salivary gland infection was seen only in D. variabilis, even though both species of ticks transmitted A. marginale to susceptible calves. A. marginale was not seen with ISH or microscopy in hemocytes collected from both species of ticks and, thus, hemocytes do not appear to play a role in the development of A. marginale in ticks.

Use of a nonradioactive DNA probe for detection of Anaplasma marginale infection in field cattle: comparison with complement fixation serology and microscopic examination

A sensitive Anaplasma marginale-specific 409-base pair DNA probe was developed in a previous study for detection of A. marginale infection in experimentally infected cattle with a test that employed slot-blot and in situ hybridization. To test the suitability of the probe to detect A. marginale in the blood of naturally infected carrier cattle, slot-blot hybridization was used to determine the infection rate of A. marginale in cattle from 3 geographic areas in Oklahoma. For comparison, blood samples from the same cattle were also examined by light microscopy and were tested by the complement fixation test. For the DNA hybridization assay, the probe was labeled with digoxigenin 11-dUTP by polymerase chain reaction (PCR). DNA was extracted from blood using the QIAamp blood kit and then applied to a nylon membrane and hybridized with the probe. The study herds consisted of 31 beef cows in Harper County, OK, and 42 and 70 dairy cows from Payne and Pittsburg counties, OK, respectively. In the 3 herds, 80.6%, 92.8%, and 57.1% of the cows were positive for A. marginale as assessed with the DNA hybridization assay. In contrast, only 25.8% and 2.86% were complement fixation positive in 2 herds, and no complement fixation positives were found in 1 herd. Uncountable parasitemia that was too low to accurately determine (< 0.01%) from 29.0%, 4.8%, and 11.4% of the samples, respectively, was demonstrated by microscopic examination. All samples positive by complement fixation and microscopic examination had positive probe reactions in the DNA hybridization assay. Therefore, the PCR-mediated nonradioactive DNA probe described here may be useful in epidemiologic investigations and in identification of carrier cattle. This assay could be adapted for use in diagnostic laboratories because it is sensitive, specific, nontoxic, quickly executed, and inexpensive.

Developmental studies of Anaplasma marginale (Rickettsiales:Anaplasmataceae) in male Dermacentor andersoni (Acari:Ixodidae) infected as adults by using nonradioactive in situ hybridization and microscopy

The development of Anaplasma marginale Theiler was studied in ticks using a nonradioactive in situ hybridization method developed in our laboratory. Male Rocky Mountain wood ticks, Dermacentor andersoni Stiles, were infected intrastadially by allowing them to feed for 7 d on an infected calf (acquisition feeding). The ticks were then removed and held in a humidity chamber for 5 d before being fed on a 2nd susceptible call for 10 d (transmission feeding). Two groups of 10 ticks were collected daily during the 22-d experiment. In one group one-half of each tick was processed and embedded in paraffin and in the other group one-half of each tick was embedded in LR White for in situ hybridization. The companion tick halves from each group were fixed and embedded in Dow Epoxy Resin resin for routine light and electron microscopy. As detected by in situ hybridization on LR White- and paraffin-embedded sections and by microscopy, initial infection of A. marginale in ticks occurred in gut tissues either on the 7th d of acquisition feeding or the 1st d of the held period and infection persisted throughout transmission feeding. The highest number of ticks with gut infection was observed on the 5th d of transmission feeding. Salivary glands became infected with A. marginale on the 1st day of transmission feeding and remained infected throughout the transmission feeding period. Peak infection was observed on day 4 of transmission feeding. After the beginning of transmission feeding, A. marginale infection was also observed in interstitial, reproductive, skeletal muscle, fat body, and Malpighian tubule tissues. Although A. marginale infection of ticks clearly originates in midgut epithelial cells, many tissues eventually become infected during transmission feeding, resulting in a generalized infection. The infection of multiple tissues may contribute to the ability of A. marginale infection to persist in intrastadially infected male ticks.

Establishment of the tick (Acari:Ixodidae)-borne cattle pathogen Anaplasma marginale (Rickettsiales:Anaplasmataceae) in tick cell culture

Anaplasma marginale is a tick-borne rickettsia that causes bovine anaplasmosis worldwide. Despite its importance, A. marginale has thus far not been established in a continuous culture system. We have propagated A. marginale continuously for the 1st time in a tick cell line derived from the black-legged tick, Ixodes scapularis Say, using infected bovine blood as the inoculum. Erythrocytic stages invaded the tick cells and multiplied in membrane-lined vacuoles to form colonies typical of those observed in naturally infected ticks as demonstrated by light and electron microscopy. The rickettsiae have been passaged serially for 3 yr and have been cryopreserved in liquid nitrogen. Antigens present in A. marginale from tick cell culture were recognized by bovine immune serum against the blood stages of A. marginale. A. marginale grown in this tick cell line was infective for calves, and male ticks fed on the calves transmitted A. marginale to a susceptible calf. The ability to culture A. marginale removes a major impediment to the study of Anaplasma biology in vitro, and will enhance development of vaccines and diagnostic tests.

Detection of Anaplasma marginale DNA in bovine erythrocytes by slot-blot and in situ hybridization with a PCR-mediated digoxigenin-labeled DNA probe

A 409-base pair (bp) DNA fragment derived from the msp-1 beta gene of Anaplasma marginale was amplified and simultaneously labeled with digoxigenin-11-dUTP by a polymerase chain reaction (PCR) assay. The resulting digoxigenin-labeled 409-bp PCR product was used as a probe for slot-blot and in situ hybridization to detect A. marginale DNA from experimentally infected bovine erythrocytes. The hybrid formation was detected with alkaline phosphatase-conjugated anti-digoxigenin antibody and substrates 5-bromo-4-chloro-3-indolyl phosphate and nitroblue tetrazolium salt. In slot-blot hybridizations, the probe detected A. marginale DNA from approximately 1,000-10,000 infected erythrocytes in 1.25 ml of whole blood, which is equivalent to a parasitemia level of 0.00001%. The probe proved to be a A. marginale-specific when tested with 17 species of microorganisms. The applicability of the probe for diagnosis was tested by screening A. marginale infections in 2 experimentally infected splenectomized cattle before microscopically detectable parasitemias and after acute infection. After inoculation of infected blood, A. marginale infections were detected with the probe 14 days prior to detection in stained smears. Microscopically inapparent parasitemias were also detected with the probe for 2 months after acute disease. When the probe was used for in situ hybridization on methanol-fixed blood smears, probe reaction could be visualized with light microscopy on A. marginale inclusions within infected erythrocytes. The probe reaction was not observed on leukocytes and uninfected erythrocytes from infected blood smears, on erythrocytes from uninfected blood samples, or on samples infected with A. ovis, Babesia bovis, or B. bigemina. This PCR-mediated nonradioactive probe appears to be a sensitive diagnostic test for A. marginale.

A survey of phlebotomine sandflies (Diptera: Psychodidae) in Hubei Province, China

From June to August, 1987 a survey of phlebotomine sandflies was carried out by means of aspirator and light-sticky traps in nine counties viz., Yunxi, Wudangshan, Snennongjia, Zigui, Yichang, Lichuan, Laifeng, Hongan and Yangxin, Hubei Province. A total of nine species had been identified: Phlebotomus chinensis, P. kiangsuensis, P. mongolensis, Sergentomyia anhuiensis, S. koloshanensis, S. nankingensis, S. squamirostris, S. zhengjiani and S. barraudi. Their distribution was summarized in a map.