Limited amounts of dendritic cells migrate into the T-cell area of lymph nodes but have high immune activating potential in melanoma patients.

PURPOSE: The success of immunotherapy with dendritic cells (DC) to treat cancer is dependent on effective migration to the lymph nodes and subsequent activation of antigen-specific T cells. In this study, we investigated the fate of DC after intradermal (i.d.) or intranodal (i.n.) administration and the consequences for the immune activating potential of DC vaccines in melanoma patients. EXPERIMENTAL DESIGN: DC were i.d. or i.n. administered to 25 patients with metastatic melanoma scheduled for regional lymph node resection. To track DC in vivo with scintigraphic imaging and in lymph nodes by immunohistochemistry, cells were labeled with both [(111)In]-indium and superparamagnetic iron oxide. RESULTS: After i.d. injection, maximally 4% of the DC reached the draining lymph nodes. When correctly delivered, all DC were delivered to one or more lymph nodes after i.n. injection. Independent of the route of administration, large numbers of DC remained at the injection site, lost viability, and were cleared by infiltrating CD163+ macrophages within 48 hours. Interestingly, 87 +/- 10% of the surviving DC preferentially migrated into the T-cell areas, where they induced antigen-specific T-cell responses. Even though more DC reached the T-cell areas, i.n. injection of DC induced similar antigen-specific immune responses as i.d. injection. Immune responses were already induced with <5 x 10(5) DC migrating into the T-cell areas. CONCLUSIONS: Monocyte-derived DC have high immune activating potential irrespective of the route of vaccination. Limited numbers of DC in the draining lymph nodes are sufficient to induce antigen-specific immunologic responses.

Preoperative 3T MR imaging of rectal cancer: local staging accuracy using a two-dimensional and three-dimensional T2-weighted turbo spin echo sequence.

PURPOSE: The purpose of our study was to evaluate the image quality and diagnostic performance of two-dimensional (D) turbo spin echo (TSE) and 3D T2-weighted TSE MR imaging in local staging of rectal cancer at 3T. MATERIALS AND METHODS: 3T phased-array MR imaging was performed in 36 consecutive patients with biopsy-proven rectal cancer. High-resolution 2D TSE images in three planes and 3D TSE images of the rectum were obtained. Two independent observers performed an image quality assessment using eight image quality characteristics. All 2D and 3D datasets were evaluated separately. MR images were prospectively evaluated by two experienced radiologists in consensus with regard to local disease. Total mesorectal excision was used as the standard of reference. The sensitivity, specificity, positive and negative predictive value, and overall accuracy were calculated. Areas under the receiver operating characteristic (ROC) curve (AUC) were determined. RESULTS: Twenty-two patients who underwent a total mesorectal excision were enrolled in this study. Significantly more motion artifacts were present with 3D TSE imaging (P=0.04). The overall sensitivity, specificity, and accuracy of muscularis propria invasion in rectal cancer using 2D T2-weighted images were 100%, 66%, and 95%, respectively. There was a statistical significant greater AUC using 2D T2-weighted images compared to 3D T2-weighted MR images (P=0.04). The ROC curves describing the results of the interpretation of 2D and 3D T2-weighted datasets regarding perirectal tissue invasion showed no statistical significant difference (P=0.41). CONCLUSIONS: In this study, high local staging accuracies with 3T 2D T2-weighted MR imaging were demonstrated. 3D T2-weighted MR imaging cannot replace 2D MR imaging for local staging of rectal cancer. However, 3D MR imaging can be used for visualization of the complex pelvic anatomy for treatment planning purposes.

Immunomonitoring tumor-specific T cells in delayed-type hypersensitivity skin biopsies after dendritic cell vaccination correlates with clinical outcome.

PURPOSE: Tumor-specific immunomonitoring is essential to evaluate the efficacy of vaccination against cancer. In this study, we investigated the predictive value of the presence or absence of antigen-specific T cells in biopsies from delayed-type hypersensitivity (DTH) sites. PATIENTS AND METHODS: In our ongoing clinical trials, HLA-A2.1+ melanoma patients were vaccinated with mature dendritic cells (DC) pulsed with melanoma-associated peptides (gp100 and tyrosinase) and keyhole limpet hemocyanin. RESULTS: After intradermal administration of a DTH challenge with gp100- and tyrosinase peptide-loaded DC, essentially all patients showed a positive induration. In clinically responding patients, T cells specific for the antigen preferentially accumulated in the DTH site, as visualized by in situ tetramer staining. Furthermore, significant numbers of functional gp100 and tyrosinase tetramer-positive T cells could be isolated from these DTH biopsies, in accordance with the applied antigen in the DTH challenge. We observed a direct correlation between the presence of DC vaccine-related T cells in the DTH biopsies of stage IV melanoma patients and a positive clinical outcome (P = .0012). CONCLUSION: These findings demonstrate the potency of this novel approach in the monitoring of vaccination studies in cancer patients.

Effective migration of antigen-pulsed dendritic cells to lymph nodes in melanoma patients is determined by their maturation state.

Dendritic cells are the professional antigen-presenting cells of the immune system. To induce an effective immune response, these cells should not only express high levels of MHC and costimulatory molecules but also migrate into the lymph nodes to interact with naïve T cells. Here, we demonstrate that in vitro-generated mature, but not immature dendritic cells, efficiently migrate into the T-cell areas of lymph nodes of melanoma patients. This difference is confirmed by in vitro studies, in which immature dendritic cells are strongly adherent, whereas mature dendritic cells remain highly motile. Our present findings demonstrate that the ability of dendritic cells to mount a proper immune response correlates with their ability to migrate both in vitro and in vivo.

Quality control of involved-field radiotherapy in patients with advanced Hodgkin's lymphoma (EORTC 20884).

PURPOSE: To evaluate the impact of the quality of involved-field radiotherapy (IFRT) on clinical outcome in patients with advanced Hodgkin's lymphoma (HL) in complete remission (CR) after six to eight cycles of mechlorethamine, vincristine, procarbazine, prednisone-doxorubicin, bleomycin, and vinblastine (MOPP-ABV) chemotherapy. METHODS AND MATERIALS: A retrospective review of clinical and radiologic data, radiation charts, simulator films, and megavoltage (MV) photographs was performed. IFRT consisted of 24 Gy to all initially involved nodal areas and 16-24 Gy to all initially involved extranodal sites. Major violations were defined as no or only partial irradiation of an originally involved area, or a total dose <90% of the prescribed dose. RESULTS: Of the 739 patients who were enrolled in the trial between 1989 and 2000, 57% achieved a CR; 152 of 172 patients randomized to IFRT actually received radiotherapy; and in 135 patients, quality control was performed. The overall major violation rate was 47%, predominantly concerning target volumes. The total dose was correct in 81% of the patients. After a median follow-up of 6.5 years, there was no difference in cumulative failure rate between patients with or without major violations. There was no relationship between incidence or site of relapse and major protocol violations. CONCLUSION: In advanced-stage HL patients in complete remission after six to eight cycles of MOPP-ABV, the outcome was not influenced by violation of the radiotherapy protocol.

Spontaneous regression of a cystic retroperitoneal tumour in young women postpartum. Report of two cases.

Retroperitoneal cystic tumours are rarely found, and of these, the most common lesion is a cystic lymphangioma. We present two postpartum patients with a cystic retroperitoneal tumour which showed spontaneous regression and a review of the literature.

Aspiration-sclerotherapy results in effective control of liver volume in patients with liver cysts.

PURPOSE: To study the extent to which aspiration-sclerotherapy reduces liver volume and whether this therapy results in relief of symptoms. RESULTS: Four patients, group I, with isolated large liver cysts, and 11 patients, group II, with polycystic livers, underwent aspiration-sclerotherapy. Average volume of aspirated cyst fluid was 1,044 ml (range 225-2,000 ml) in group I and 1,326 ml (range 40-4,200 ml) in group II. Mean liver volume before the procedure was 2,157 ml (range 1,706-2,841 ml) in group I and 4,086 ml (range 1,553-7,085 ml) in group II. This decreased after the procedure to 1,757 ml (range 1,479-2,187 ml) in group I. In group II there was a statistically significant decrease to 3,347 ml (range 1,249-6,930 ml, P = 0.008). Volume reduction was 17.1% (range -34.7% to -4.1%) and 19.2% (range -53.9% to +2.4%) in groups I and II, respectively. Clinical severity of all symptoms decreased, except for involuntary weight loss and pain in group II. CONCLUSION: Aspiration-sclerotherapy is an effective means of achieving liver volume reduction and relief of symptoms.

Hepatocystin is not secreted in cyst fluid of hepatocystin mutant polycystic liver patients.

Autosomal dominant polycystic liver disease (PCLD) is characterized by multiple liver cysts and is caused by mutations in PRKCSH (hepatocystin). Mechanisms of cystogenesis are unknown, but previous studies have shown that hepatocystin is secreted in vitro. The goal of this study was to determine the fate of hepatocystin in vivo. Using immunoprecipitation, we determined that mutant hepatocystin is secreted from both apical and basolateral cell surface of MDCK cells stably transfected with mutant hepatocystin. Analysis of 60 cyst fluid samples from polycystic livers using Western blot, MALDI-TOF MS or nLC-MS/MS did not detect hepatocystin in liver cyst fluid. We did identify 163 ubiquitous serum proteins. No paracrine or autocrine factors were recognized. Although cyst fluids vary greatly in protein concentration, a PCLD specific protein pattern was not established. In conclusion, hepatocystin is not secreted in PCLD liver cyst fluid, suggesting that mutant hepatocystin is either not produced or degraded intracellularly. PCLD cysts develop from intralobular bile ductules and cyst fluid mainly contains common serum proteins comparable to that of other polycystic diseases.

Describing computed tomography findings in acute necrotizing pancreatitis with the Atlanta classification: an interobserver agreement study.

OBJECTIVES: The 1992 Atlanta classification is a clinically based classification system that defines the severity and complications of acute pancreatitis. A study was undertaken to assess the interobserver agreement of categorizing peripancreatic collections on computed tomography (CT) using the Atlanta classification. METHODS: Preoperative contrast-enhanced CTs from 70 consecutive patients (49 men; median age, 59 years; range, 29-79 years) operated for acute necrotizing pancreatitis (2000-2003) in 11 hospitals were reviewed. Five abdominal radiologists independently categorized the peripancreatic collections according to the Atlanta classification. Radiologists were aware of the timing of the CT and the clinical condition of the patient. Interobserver agreement was determined. RESULTS: Interobserver agreement among the radiologists was poor (kappa, 0.144; SD, 0.095). In 3 (4%) of 70 cases, the same Atlanta definition was chosen. In 13 (19%) of 70 cases, 4 radiologists agreed, and in 42 (60%) of 70 cases, 3 radiologists agreed on the definition. In 21 cases (30%), 1 or more of the radiologists classified a collection as "pancreatic abscess," whereas 1 or more radiologist used another Atlanta definition. CONCLUSION: The interobserver agreement of the Atlanta classification for categorizing peripancreatic collections in acute pancreatitis on CT is poor. The Atlanta classification should not be used to describe complications of acute pancreatitis on CT.