Pascale Saussoy

Reimplantation of cryopreserved ovarian tissue from patients with acute lymphoblastic leukemia is potentially unsafe.

Ovarian tissue cryopreservation is currently proposed to young cancer patients to preserve their fertility before radiochemotherapy. The potential risk is that the tissue might harbor malignant cells that could induce disease recurrence. We therefore decided to evaluate the presence of leukemic cells in cryopreserved ovarian tissue from 18 leukemic patients: 6 with chronic myeloid leukemia (CML) and 12 with acute lymphoblastic leukemia (ALL). In each case, histology, quantitative reverse-transcribed polymerase chain reaction (RT-PCR) and long-term (6 months) xenografting to immunodeficient mice were used. Histology did not identify any malignant cells in the ovarian tissue. By quantitative RT-PCR, 2 of 6 CML patients were positive for BCR-ABL in their ovarian tissue. Among the 12 ALL patients, 7 of the 10 with available molecular markers showed positive leukemic markers in their ovarian tissue (translocations or rearrangement genes). Four mice grafted with ovarian tissue from ALL patients developed intraperitoneal leukemic masses. In conclusion, this study demonstrates, by quantitative RT-PCR, ovarian contamination by malignant cells in acute as well as chronic leukemia, whereas histology fails to do so. Moreover, chemotherapy before ovarian cryopreservation does not exclude malignant contamination. Finally, reimplantation of cryopreserved ovarian tissue from ALL and CML patients puts them at risk of disease recurrence.

microRNA-29c and microRNA-223 down-regulation has in vivo significance in chronic lymphocytic leukemia and improves disease risk stratification.

Aberrant expression of microRNAs has been recently associated with chronic lymphocytic leukemia (CLL) outcome. Although disease evolution can be predicted by several prognostic factors, a better outcome individualization in a given patient is still of utmost interest. Here, we showed that miR-29c and miR-223 expression levels decreased significantly with progression from Binet stage A to C were significantly lower in poor prognostic subgroups (defined by several prognostic factors) and could significantly predict treatment-free survival (TFS) and overall survival (OS). Furthermore, we developed a quantitative real-time polymerase chain reaction (qPCR) score combining miR-29c, miR-223, ZAP70, and LPL (from 0 to 4 poor prognostic markers) to stratify treatment and death risk in a cohort of 110 patients with a median follow-up of 72 months (range, 2-312). Patients with a score of 0/4, 1/4, 2/4, 3/4, and 4/4 had a median TFS of greater than 312, of 129, 80, 36, and 19 months, respectively (hazard ratio, HR(0/4 < 1/4 < 2/4 < 3/4 < 4/4) = 17.00, P < .001). Patients with a score of 0-1/4, 2-3/4, and 4/4 had a median OS of greater than 312, of 183 and 106 months, respectively (HR(0/4 < 1/4 < 2/4 < 3/4 < 4/4) = 13.69, P = .001). This score will help to identify, among the good and poor prognosis subgroups, patients who will need early therapy and thus will require a closer follow-up.

Differential association of calreticulin type 1 and type 2 mutations with myelofibrosis and essential thrombocytemia: relevance for disease evolution

Differential association of calreticulin type 1 and type 2 mutations with myelofibrosis and essential thrombocytemia: relevance for disease evolution

The immunological monitoring of kidney and liver transplants in adult and pediatric recipients

Over the last half century, kidney and liver transplantation have been recognized as the treatment of choice for adult and children with end-stage renal or liver failure. Infants present a relative naïve immune system, but they are capable of mounting both cellular and humoral immune responses to the foreign antigens presented by the allograft. Immune monitoring is a way of measuring functional and molecular correlates of immune reactivity which may provide clinically useful information for identifying patients who have an increase risk of acute rejection prior to clinical symptoms or develop transplant tolerance. However, although numerous assays have been shown to predict rejection, to date no assays have been demonstrated to detect or predict transplantation tolerance. This is a summary of the published literature on promising antigen-specific and non-antigen-specific assays used for immunological monitoring in solid organ transplantation. This work also attempts to review their applicability to pediatric transplantation, specifically, pediatric kidney and liver recipients.

Evaluation of a human ovarian follicle isolation technique to obtain disease-free follicle suspensions before safely grafting to cancer patients.

OBJECTIVE To evaluate the safety of our follicle isolation procedure in a model of ovarian tissue artificially contaminated with cancer cells, then to improve the procedure to effectively eliminate malignant cells from follicle suspensions without altering viability. DESIGN Prospective experimental study. SETTING Gynecology research unit in a university hospital. PATIENT(S) Ten women undergoing laparoscopy for benign gynecologic disease. INTERVENTION(S) Follicle isolation from ovarian tissue artificially contaminated with marked fluorescent leukemic cells, either by the usual pickup technique without further treatment (group 1) or by washing three times after pickup (group 2). MAIN OUTCOME MEASURE(S) Evidence of leukemic cells in follicle suspensions using fluorescence microscopy and quantitative real-time polymerase chain reaction, and analysis of follicle viability. RESULT(S) In group 1, 196 leukemic cells were detected by fluorescence microscopy out of 499 follicles retrieved, while just one leukemic cell was found among 772 follicles after three washes. The BCR-ABL fusion transcript was detected when at least 19 cells were present in follicle suspensions; four samples were positive in group 1, and all were negative in group 2. Follicle viability was similar in both groups (95.6% vs. 96.4%). CONCLUSION(S) Cancer cells could inadvertently be picked up with isolated follicles in case of malignant contamination of ovarian tissue. A simple purging procedure consisting of three washes proved effective for eliminating leukemic cells while maintaining good follicle viability.

Eliminating malignant cells from cryopreserved ovarian tissue is possible in leukaemia patients

Reimplantation of cryopreserved ovarian tissue (OT) can successfully restore ovarian function in young cancer patients after gonadotoxic treatment. However, for patients with leukaemia, there is a risk of malignant cell transmission. Our objective was to evaluate minimal disseminated disease in OT from leukaemia patients and test a follicle isolation technique to obtain disease‐free follicle suspensions. Cryopreserved OT from 12 leukaemia patients was thawed and analysed by histology and long‐term xenografting in immunosuppressed mice. In 10 patients, follicles were isolated from OT, and polymerase chain reaction (PCR) was performed on tissue, digested ovarian suspensions and isolated follicle suspensions to investigate leukaemic cell presence. Mean patient age was 17·1 years. An average of 3·2 follicles were isolated per mm² of cortex. Xenografting of OT induced leukaemic masses in 2/12 mice. PCR identified leukaemic cell presence in 66% of OT. Malignant cells were also detected in digested ovarian suspensions. However, none of the follicle samples (>2300 follicles tested) showed any malignant cell presence after washing. This study demonstrates that it is possible to recover large numbers of viable follicles from cryopreserved OT of leukaemia patients. All isolated and washed follicle suspensions tested negative for leukaemic cells, giving leukaemia patients genuine hope of fertility restoration.

Mechanisms of cell death induced by 2-chloroadenosine in leukemic B-cells

2-chloroadenosine (2-CAdo) is an adenosine deaminase-resistant analogue of adenosine, widely used as an adenosine receptor agonist. This compound has been shown to induce apoptosis in several cell types either via activation of adenosine receptors or via intracellular metabolism. However, the molecular mechanisms of 2-CAdo-induced apoptosis are unclear. Here, we analyzed the effects of 2-CAdo in the leukemia cell line EHEB. 2-CAdo was found to induce apoptosis in EHEB cells, as shown by caspase-3 activation, DNA fragmentation, poly(ADP-ribose) polymerase (PARP) cleavage and phosphatidylserine exposure. Cytotoxicity of 2-CAdo was completely suppressed by 5-iodotubercidin, an adenosine kinase inhibitor, indicating that apoptosis induced by 2-CAdo was the result of its intracellular metabolism. Accordingly, we found that 2-CAdo was efficiently converted into 2-chloroATP. In parallel, a decrease of intracellular ATP concentration as well as a general inhibition of macromolecular synthesis, involving DNA, RNA and protein synthesis, was observed. Moreover, 2-CAdo induced cytochrome c release into the cytosol, indicating activation of the intrinsic pathway of apoptosis. This was found associated with a decline in Mcl-1 protein level and p53-independent. Inhibition of AMP deaminase by coformycin markedly prevented ATP depletion, and also significantly reduced 2-CAdo cytotoxicity and caspase-3 activation. In conclusion, our data show that intracellular metabolism of 2-CAdo can lead to activation of the intrinsic pathway of apoptosis and that ATP depletion, in addition to the accumulation of the triphosphate analogue, contributes to 2-CAdo-induced apoptosis.

Is transplantation of a few leukemic cells inside an artificial ovary able to induce leukemia in an experimental model

PurposeTo evaluate the tumor-inducing ability of a few leukemic cells xenotransplanted inside an artificial ovary.MethodsTen and 100 BV-173 leukemic cells were embedded in a fibrin matrix along with 50,000 human ovarian stromal cells, and grafted to the peritoneal bursa of 5 and 5 SCID mice respectively. Four mice grafted with 3x106 leukemic cells in fibrin served as positive controls. At 20 weeks post-transplantation, the grafts, liver, spleen, blood and bone marrow were analyzed for the presence of leukemia by anti-CD79α IHC, flow cytometry (FC) and PCR.ResultsAll mice grafted with 3x106 cells developed peritoneal masses 4 weeks after xenotransplantation, and systemic disease was confirmed by IHC, PCR and FC. Among mice grafted with 10 or 100 leukemic cells, none showed any sign of leukemia after 20 weeks, and IHC, FC and PCR on the different recovered tissues all proved negative.ConclusionThis study investigates the tumor-inducing potential of a few leukemic cells grafted inside an artificial ovary. Transplantation of 100 leukemic cells appears to be insufficient to induce leukemia after 20 weeks. These results in an immunodeficient xenografting model are quite reassuring. However, for clinical application, follicle suspensions must be purged of leukemic cells before grafting, as even the slightest risk should be avoided.

Impaired up‐regulation of polo‐like kinase 2 in B‐cell chronic lymphocytic leukaemia lymphocytes resistant to fludarabine and 2‐chlorodeoxyadenosine: a potential marker of defective damage response

The functional evaluation of ataxia telangiectasia mutated (ATM) and p53 was recently developed in B‐cell chronic lymphocytic leukaemia (B‐CLL), a disease in which the response to DNA damage is frequently altered. We identified a novel biomarker of chemosensitivity based on the induction of DNA damage by the purine nucleoside analogues (PNA) fludarabine and 2‐chlorodeoxyadenosine (CdA). Using genome‐wide expression profiling, it was observed that, in chemosensitive samples, PNA predominantly increased the expression of p53‐dependent genes, among which PLK2 was the most highly activated at early time points. Conversely, in chemoresistant samples, p53‐dependent and PLK2 responses were abolished. Using a quantitative real time polymerase chain reaction, we confirmed that PNA dose‐ and time‐dependently increased PLK2 expression in chemosensitive but not chemoresistant B‐CLL samples. Analysis of a larger cohort of B‐CLL patients showed that cytotoxicity induced by PNA correlated well with PLK2 mRNA induction. Interestingly, we observed that failure to up‐regulate PLK2 following PNA and chemoresistance were not strictly correlated with structural alterations in the TP53 gene. In conclusion, we propose that testing PLK2 activation after a 24‐h incubation with PNA could be used to investigate the functional integrity of DNA damage‐response pathways in B‐CLL cells, and predict clinical sensitivity to these drugs.

Management of pregnancy in paroxysmal nocturnal hemoglobinuria on long-term eculizumab.

Pregnancy in women with paroxysmal nocturnal hemoglobinuria (PNH) is associated with increased maternal and fetal complications, to such an extent that PNH has for long been considered a relative contraindication for pregnancy. The most serious life-threatening complications are venous thromboembolic events, the risk of which is increased by the hypercoagulable state related to pregnancy. Eculizumab, a C5 complement inhibitor, has revolutionized the treatment of PNH. However, there are no published trials evaluating its use in pregnancy. Most recommendations are based on expert opinions and case reports. We report on the favorable outcome of a PNH patient who became pregnant while under eculizumab, suggesting that this drug can be given from conception to delivery.