Based on the fluorescent properties of the dye rhodamine 123 (Rh123), which is transported by the membrane efflux pump P-glycoprotein (P-gp), we developed a functional flow cytometric assay for the detection of multidrug-resistant (MDR) cells. Using drug sensitive cell lines (KB-3-1) and MDR mutants (KB-8-5, KB-C1) experimental conditions were established that enabled demonstration of significant differences in Rh123 efflux and accumulation. Subsequently we investigated the applicability of this functional assay for the prediction of MDR in human peripheral blood and bone marrow samples. Using two-colour flow cytometry, the leukaemic blast cells of six patients suffering from acute myeloid leukaemia (AML) were analysed. In three cases the blast cells showed a rapid and marked Rh123 efflux. In the presence of MDR inhibitors these cells retained Rh123. To determine whether the efflux of Rh123 was associated with P-gp expression, the leukaemic cells were stained with the monoclonal antibody MRK-16. In addition extracted RNA was analysed by polymerase chain reaction to evaluate the expression of mdr 1 mRNA. In all three Rh123+ cases mdr 1 mRNA was detectable whereas only one AML case expressed P-gp. In comparing Rh123 with daunorubicin, which also allows the detection of MDR cells, accumulation studies proved Rh123 to be the more sensitive drug for flow cytometric MDR screening. Additionally, two-colour flow cytometry was much easier to perform with Rh123 than with daunorubicin. Our results indicate that flow cytometric measurement of Rh123 accumulation/efflux proves applicable to detect MDR cells in heterogenous clinical samples.

In this first study, topically applied low-dose rhu GM-CSF was a safe treatment for chronic venous leg ulcers. Healing rates were significantly increased and relapse rates were minimal.

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The aim of this study was to investigate to which extent acute leukemias could be monitored for residual disease by using atypical antigen combinations as leukemia-related markers. Atypical antigenic features were determined by double color flow cytometry and included coexpression of lymphoid and myeloid related antigens, unphysiological coexpression of immature and mature antigens, and lack of an antigen that is normally expressed during maturation. Atypical immunophenotypes were detected in 35 of 68 patients with AML (51.5%) and 15 of 24 patients with ALL (62.5%). When 12 patients with leukemia-associated markers were again analyzed at relapse, the relevant antigen combinations were retained in 11 of them. The sensitivity of this two color flow cytometric assay as determined in dilution experiments was 1 in lo3 to lo4 cells.Follow-up studies of bone marrow samples revealed that, after induction chemotherapy cells with leukemia-associated markers were detectable in several patients at a frequency of 0.5 to 4%, but only patients in whom the cells with atypical antigens never disappeared suffered from relapse. In contrast, patients who became negative for the atypical cells remained in complete remission (median remission duration after the first negative bone marrow assessment by flow cytometry 52 weeks, range 20-102).We conclude that atypical antigen combinations, which are present in a meaningful number of acute leukemias, are a valuable means of monitoring acute leukemia patients during follow-up. This flow cytometric approach can complement other strategies to get a more accurate definition of remission in acute leukemia. o 1992 Wiley-Liss, Inc.

Purpose: Cancer of the uterine cervix is an important cause of death in women worldwide. Pap smears as a tool for screening decreased the incidence and mortality of cervical cancer dramatically. This proof of principle study aimed to develop a potential tool for cervical screening using a test that can be applied by patients without visiting a physician and to increase the coverage rate, especially of the high-risk population with low socioeconomic status.Experimental Design: Human papillomavirus (HPV) DNA testing and methylation analysis of DNA obtained from cervicovaginal specimens of 13, 31, and 11 patients with no dysplasia/low-grade squamous intraepithelial lesion (SIL), high-grade SIL, and invasive cervical cancer, respectively, collected on a tampon, was performed using PCRbased methods to detect invasive cervical cancer and study whether these changes are already present in the precursor lesions.Results: High-risk HPV DNA was present in 68 and 82% of patients with high-grade SIL and invasive cervical cancer. DNA methylation of the 11 genes tested increased with severity of the cervical lesion. Unsupervised hierarchical cluster analysis using solely information on DNA methylation of the 11 genes was able to predict the presence of invasive cervical cancers: one of the two clusters formed contained 9 of 11 invasive cervical cancers, as well as two high-grade SILs.Conclusions: HPV DNA and DNA methylation analyzed in cervicovaginal specimens are able to predict invasive cervical cancers. To detect all high-grade SILs when applying this test, genes that become methylated earlier throughout cervical carcinogenesis have to be defined.

The multidrug-resistance gene, MDR1 is expressed in many normal tissues, but little is known about its expression in normal hematopoietic cells. Using the monoclonal antibody C219 and flow cytometric analysis, P-glycoprotein (P-gp) was found to be expressed in all peripheral blood (PB) subpopulations (CD4, CD8, CD14, CD19, CD56) except granulocytes. To specifically determine MDR1 gene expression, these PB subpopulations were isolated by fluorescence-activated cell sorting (FACS) and analyzed for MDR1 mRNA by polymerase chain reaction (PCR). All subsets were positive by PCR, but only minimal MDR1 mRNA was detected in monocytes and granulocytes. Significant efflux of Rhodamine- 123 (Rh-123), a measure of P-gp function, was detected in CD4+, CD8+, CD14+, CD19+, and CD56+ cells but not in granulocytes. Next, PCR- analysis was performed on FACS-sorted bone marrow (BM) cells to assess MDR1 expression in different maturational stages. Precursors (CD34+), early and late myeloid cells (CD33+/CD34+, CD33+/CD34-) as well as lymphocytes of the B-cell lineage (CD19+/CD10+, CD19+/CD10-) expressed the MDR1 gene. BM monocytic cells (CD33++/CD34-) were negative, and a very weak signal was detected in erythroid cells (glycophorin A+). Significant Rh-123 efflux was found in CD34+, CD10+, CD33+, and CD33++ BM cells, but not in glycophorin A+ cells. We conclude that PB and BM lymphocytes, PB monocytes, BM progenitors, and immature myeloid cells, but not late BM monocytes, erythroid cells, and PB granulocytes, express MDR1 mRNA and a functional P-gp. These results have to be taken into account when MDR1 expression is determined in tumor samples containing normal blood cells.

The multidrug-resistance gene, MDR1 is expressed in many normal tissues, but little is known about its expression in normal hematopoietic cells. Using the monoclonal antibody C219 and flow cytometric analysis, P-glycoprotein (P-gp) was found to be expressed in all peripheral blood (PB) subpopulations (CD4, CD8, CD14, CD19, CD56) except granulocytes. To specifically determine MDR1 gene expression, these PB subpopulations were isolated by fluorescence-activated cell sorting (FACS) and analyzed for MDR1 mRNA by polymerase chain reaction (PCR). All subsets were positive by PCR, but only minimal MDR1 mRNA was detected in monocytes and granulocytes. Significant efflux of Rhodamine- 123 (Rh-123), a measure of P-gp function, was detected in CD4+, CD8+, CD14+, CD19+, and CD56+ cells but not in granulocytes. Next, PCR- analysis was performed on FACS-sorted bone marrow (BM) cells to assess MDR1 expression in different maturational stages. Precursors (CD34+), early and late myeloid cells (CD33+/CD34+, CD33+/CD34-) as well as lymphocytes of the B-cell lineage (CD19+/CD10+, CD19+/CD10-) expressed the MDR1 gene. BM monocytic cells (CD33++/CD34-) were negative, and a very weak signal was detected in erythroid cells (glycophorin A+). Significant Rh-123 efflux was found in CD34+, CD10+, CD33+, and CD33++ BM cells, but not in glycophorin A+ cells. We conclude that PB and BM lymphocytes, PB monocytes, BM progenitors, and immature myeloid cells, but not late BM monocytes, erythroid cells, and PB granulocytes, express MDR1 mRNA and a functional P-gp. These results have to be taken into account when MDR1 expression is determined in tumor samples containing normal blood cells.

Peripheral blood lymphocyte (PBL) subsets and bone marrow biopsies were analysed in six patients with hairy cell leukaemia (HCL) treated with 2'-deoxycoformycin (pentostatin, DCF) according to a phase II trial of the EORTC Leukemia Cooperative Group. All patients responded to DCF with four complete and two partial remissions according to conventional criteria. Within the PBL subsets, major changes concerned the CD4+ T cells, which during DCF therapy were distinctly suppressed to nadir values of 0.038-0.18 (median 0.126) x 10(9)/l. In five patients these cells returned to normal 3.0-49.5 (median 14.5) months after the last DCF injection. CD8+ cells were decreased to a lesser extent, and NK cell numbers improved during treatment. Bone marrow immunohistology applying the MoAb B-ly7 demonstrated residual hairy cells (HCs) in all of the six patients following DCF treatment with nadir HC numbers of 0.2-3.0% of bone marrow cells. Immunoglobulin gene rearrangement analysis of DNA obtained from these biopsies showed only germline bands, whereas rearranged bands had been present on the pretreatment specimens. Within the observation period of 15.5-54.0 (median 47.0) months after discontinuation of DCF therapy, immunohistology demonstrated a continuous increase in HC numbers in five of the six patients with clonal rearrangement detectable in bone marrow specimens from three of these patients at last follow-up date. Although established on the basis of a small number of patients, these data suggest that DCF treatment as currently employed in HCL is unable to eradicate the malignant B cell clone.