Evaluation of Murex CMV DNA Hybrid Capture Assay for Detection and Quantitation of Cytomegalovirus Infection in Patients following Allogeneic Stem Cell Transplantation

Murex hybrid capture DNA assay (HCS) is a solution hybridization antibody capture assay for detection and quantitation of cytomegalovirus (CMV) DNA in leukocytes. To determine whether CMV HCS is sensitive enough to initiate and monitor antiviral therapy after allogeneic stem cell transplantation (SCT), 51 consecutive SCT recipients were prospectively screened for the appearance of CMV infection by HCS, PCR, and culture assays from blood samples. Preemptive antiviral therapy was initiated after the second positive PCR result in all patients, as previously reported, and HCS was not considered for clinical decision making. A total of 417 samples were analyzed. Of these, 21 samples were found to be positive by PCR and HCS, 88 samples were PCR positive but HCS negative, and 308 were negative by both assays. Concordance of results between PCR and HCS and between HCS and blood culture was observed in 78.9 and 95.9% of the samples assayed, respectively. PCR was found to be more sensitive than HCS, and HCS was more sensitive than the blood culture assay (P < 0.0001). Four patients with symptomatic CMV infection were PCR positive prior to the onset of CMV-related symptoms, whereas HCS detected CMV DNA in three patients prior to and one at onset of CMV disease. The numbers of genomes per milliliter of blood were higher in patients with symptomatic CMV infection than in those with asymptomatic CMV infection (P = 0.06). None of the HCS-negative patients developed CMV disease. Thus, all patients with CMV disease were correctly identified by HCS; however, the lower sensitivity limit of the HCS assay may still be insufficient to allow diagnosis of CMV infection early enough to prevent CMV disease in patients following allogeneic SCT.     

The influence of gemcitabine on the CD4/CD8 ratio in patients with solid tumours

Gemcitabine (dFdC) is a novel pyrimidine antimetabolite with documented antineoplastic activity against metastatic non-small cell lung cancer (NSCL), pancreatic carcinoma, ovarian and breast cancer. The side effects of gemcitabine are generally mild; severe infections are reported in less than Ilo of patients. In contrast, other new nucleoside analogues such as the purine antimetabolite fludarabine lead to a significant alteration of the CD4/CD8 lymphocyte ratio associated with an increased risk for opportunistic infections. This study investigates the effect of gemcitabine on different lymphocyte subsets during consecutive applications. 16 patients with solid rumours (3 non-small cell lung cancer, 3 pancreas, 3 testicular, 2 breast, ovarian germ-cell, 1 ovarian, 1 small cell lung, 1 gastric cancer, 1 carcinoma of unknown primary); 15 patients were previously treated, received at least 3 applications of gemcitabine (1,000 mg/m(2) as a 30 min infusion, at days 1, 8, 15; q 4 weeks). Lymphocytes surface antigens were analysed by standard technique flow cytometry prior to every infusion. The median number of leukocytes before therapy was 7823/mu l, with lymphocytes 875/mu l, including 68% T-cells (CD3(+)), 9% B-cells (CD19(+); CD20(+)) and 15% NK-cells (CD56(+); CD16(+); CD3(-)), the CD4/CD8 ratio was 1.7. After gemcitabine therapy the median number of leukocytes was 5136/mu l, with lymphocytes 1012/mu l, including 77% T-cells, 8% B-cells and 10% NK-cells and a CD4/CD8 ratio of 2.2. Severe complications or opportunistic infections were not seen in these 16 patients. No significant change of CD4/CD8 ratios and NK-ccll numbers was seen in our patients with solid tumours during weekly treatment with gemcitabine. A severely increased risk for opportunistic infections following treatment with the new antimetabolite gemcitabine appears unlikely.     

Expression of her-2/neu on acute lymphoblastic leukemias: implications for the development of immunotherapeutic approaches.

Her-2/neu is a tumor-associated antigen that is expressed on several adenocarcinomas and correlates with poor prognosis. In a previous study (H. J. Bühring et al., Blood, 86: 1916-1923, 1995), it has been demonstrated that Her-2/neu expression can be detected on blast cells from patients with hematological malignancies including acute lymphoblastic leukemia (ALL). Here, we show that Her-2/neu-specific CTLs induced in vitro using peptide-pulsed dendritic cells efficiently lyse primary ALL blasts constitutively expressing both Her-2/neu and human leukocyte antigen A2 in an antigen-specific and MHC-restricted manner. Furthermore, we analyzed the feasibility of this approach in an autologous setting and induced Her-2/neu-specific CTLs using dendritic cells generated from peripheral blood mononuclear cells from an ALL patient that were pulsed with peptides or transfected with in vitro-transcribed Her-2/neu mRNA. Our data demonstrate that Her-2/neu could be used as a potential target for the application of Her-2/neu-directed treatment strategies in ALL including vaccination approaches.     

Mitochondrial dysfunction occurs before transport or tight junction deficits in biliary epithelial cells exposed to bile from methylenedianiline-treated rats.

Methylenedianiline (DAPM) rapidly injures biliary epithelial cells (BEC) in vivo. Prior to evident BEC injury, biliary glucose and inorganic phosphate appreciably rise, which could stem from loosened tight junctions (TJ). Concurrently, ultrastructural abnormalities in BEC mitochondria of DAPM-treated animals are observed, suggesting other impairments. Our objective was to develop an in vitro BEC model to assess the time course of impairments in TJ integrity, glucose uptake, and mitochondrial function following DAPM exposure. We exposed monolayers of primary, polarized rat BEC to bile collected from rats prior to (Basal Bile) or after oral treatment (DAPM-Bile) with 50 mg DAPM/kg. DAPM-Bile collected during 0-60 min (1st Hr) and during 61-120 min (2nd Hr) after treatment was pooled from four to six rats. When monolayers were exposed to 1st Hr DAPM-Bile for 120 min, metabolic activity (XTT assay) decreased approximately 75%, and transepithelial resistance decreased approximately 16% in agreement with an approximately 65% increase in leakage of a glucose analog, methyl-alpha-D-glucopyranoside (AMG), from apical to basolateral media. By 60 min, AMG uptake was decreased approximately 40%. Mitochondrial function was very rapidly compromised, with approximately 120% increases in the green-to-red fluorescence ratio of JC-1 (mitochondrial membrane potential dye) at 15 min and approximately 55% decreases in ATP levels at 30 min. This sequence of events indicates that DAPM impairs BEC mitochondria prior to impairments in glucose uptake or TJ integrity. Thus, our in vitro primary rat BEC/bile exposure model mimics in vivo observations and yields basic information about the time course of events that occur during DAPM-induced injury.