SAKK 16/14: Durvalumab in Addition to Neoadjuvant Chemotherapy in Patients With Stage IIIA(N2) Non-Small-Cell Lung Cancer-A Multicenter Single-Arm Phase II Trial.

PURPOSE: For patients with resectable stage IIIA(N2) non-small-cell lung cancer, neoadjuvant chemotherapy with cisplatin and docetaxel followed by surgery resulted in a 1-year event-free survival (EFS) rate of 48% in the SAKK 16/00 trial and is an accepted standard of care. We investigated the additional benefit of perioperative treatment with durvalumab. METHODS: Neoadjuvant treatment consisted of three cycles of cisplatin 100 mg/m2 and docetaxel 85 mg/m2 once every 3 weeks followed by two doses of durvalumab 750 mg once every 2 weeks. Durvalumab was continued for 1 year after surgery. The primary end point was 1-year EFS. The hypothesis for statistical considerations was an improvement of 1-year EFS from 48% to 65%. RESULTS: Sixty-eight patients were enrolled, 67 were included in the full analysis set. Radiographic response rate was 43% (95% CI, 31 to 56) after neoadjuvant chemotherapy and 58% (95% CI, 45 to 71) after sequential neoadjuvant immunotherapy. Fifty-five patients were resected, of which 34 (62%) achieved a major pathologic response (MPR; ≤ 10% viable tumor cells) and 10 (18%) among them a complete pathologic response. Postoperative nodal downstaging (ypN0-1) was observed in 37 patients (67%). Fifty-one (93%) resected patients had an R0 resection. There was no significant effect of pretreatment PD-L1 expression on MPR or nodal downstaging. The 1-year EFS rate was 73% (two-sided 90% CI, 63 to 82). Median EFS and overall survival were not reached after 28.6 months of median follow-up. Fifty-nine (88%) patients had an adverse event grade ≥ 3 including two fatal adverse events that were judged not to be treatment-related. CONCLUSION: The addition of perioperative durvalumab to neoadjuvant chemotherapy in patients with stage IIIA(N2) non-small-cell lung cancer is safe and exceeds historical data of chemotherapy alone with a high MPR and an encouraging 1-year EFS rate of 73%.

Binimetinib, pemetrexed and cisplatin, followed by maintenance of binimetinib and pemetrexed in patients with advanced non-small cell lung cancer (NSCLC) and KRAS mutations. The phase 1B SAKK 19/16 trial.

BACKGROUND: KRAS mutations are found in 20-25 % of non-squamous non-small cell lung cancer (NSCLC) and therapies targeting the RAS/MEK/ERK pathway are in development. We performed a multicenter open-label phase 1B trial to determine the recommended phase 2 dose and early antitumor activity of the MEK-inhibitor binimetinib combined with cisplatin and pemetrexed. METHODS: Eligible patients (pts) had stage III-IV NSCLC unsuitable for curative treatment, KRAS exon 2 or 3 (codon 12, 13 or 61) mutations, no prior systemic therapy. Pts were enrolled into part 1: 3 + 3 design with dose escalation in 2 dose levels (DL) of binimetinib and part 2: expansion cohort at the maximum tolerated dose (MTD). Pts received 4 cycles of cisplatin 75 mg/m2, pemetrexed 500 mg/m2and binimetinib 30 (DL1)/45 mg (DL2) orally twice a day (bid) d1-14 q3w followed by pemetrexed and binimetinib until progressive disease (PD) or unacceptable toxicity. RESULTS: From May 2017 to Dec 2019, 18 pts (13 dose escalation, 5 expansion cohort) were enrolled. Median age was 60 (48-73, range). KRAS mutations were 87.5 % at codon 12. No DLT occurred in the dose escalation cohort. Median number of cycles was 2 (1-17, range). Treatment discontinuation was mainly due to PD (33 %) or pts/physicians' decision (27 %). Together with the expansion cohort, 16 pts were evaluable for safety. Most frequent treatment-related grade 3 AEs were lung infection (25 %), fatigue (19 %), anemia (19 %). Overall response rate among 9 evaluable pts receiving binimetinib at MTD (45 mg bid) was 33 % (7-70 %, 95 % CI). Median progression-free survival was 5.7 months (1.1-14.0, 95 % CI) and overall survival 6.5 months (1.8-NR, 95 % CI). CONCLUSIONS: Pts treated with combination of cisplatin, pemetrexed and binimetinib presented no unexpected toxicity. No early signal of increased antitumor activity of binimetinib added to chemotherapy was observed in our pts population.

Prolonged rituximab maintenance in follicular lymphoma patients: long-term results of the SAKK 35/03 randomized trial.

The Swiss Group for Clinical Cancer Research (SAKK) conducted the SAKK 35/03 randomized trial (NCT00227695) to investigate different rituximab monotherapy schedules in patients with follicular lymphoma (FL). Here, we report their long-term treatment outcome. Two-hundred and seventy FL patients were treated with 4 weekly doses of rituximab monotherapy (375 mg/m2); 165 of them, achieving at least a partial response, were randomly assigned to maintenance rituximab (375 mg/m2 every 2 months) on a short-term (4 administrations; n = 82) or a long-term (up to a maximum of 5 years; n = 83) schedule. The primary end point was event-free survival (EFS). At a median follow-up period of 10 years, median EFS was 3.4 years (95% confidence interval [CI], 2.1-5.5) in the short-term arm and 5.3 years (95% CI, 3.5-7.5) in the long-term arm. Using the prespecified log-rank test, this difference is not statistically significant (P = .39). There also was not a statistically significant difference in progression-free survival or overall survival (OS). Median OS was 11.0 years (95% CI, 11.0-NA) in the short-term arm and was not reached in the long-term arm (P = .80). The incidence of second cancers was similar in the 2 arms (9 patients after short-term maintenance and 10 patients after long-term maintenance). No major late toxicities emerged. No significant benefit of prolonged maintenance became evident with longer follow-up. Notably, in symptomatic patients in need of immediate treatment, the 10-year OS rate was 83% (95% CI, 73-89%). These findings indicate that single-agent rituximab may be a valid first-line option for symptomatic patients with advanced FL.

Rituximab Maintenance for a Maximum of 5 Years After Single-Agent Rituximab Induction in Follicular Lymphoma: Results of the Randomized Controlled Phase III Trial SAKK 35/03.

PURPOSE: Rituximab maintenance therapy has been shown to improve progression-free survival in patients with follicular lymphoma; however, the optimal duration of maintenance treatment remains unknown. PATIENTS AND METHODS: Two hundred seventy patients with untreated, relapsed, stable, or chemotherapy-resistant follicular lymphoma were treated with four doses of rituximab monotherapy in weekly intervals (375 mg/m(2)). Patients achieving at least a partial response were randomly assigned to receive maintenance therapy with one infusion of rituximab every 2 months, either on a short-term schedule (four administrations) or a long-term schedule (maximum of 5 years or until disease progression or unacceptable toxicity). The primary end point was event-free survival (EFS). Progression-free survival, overall survival (OS), and toxicity were secondary end points. Comparisons between the two arms were performed using the log-rank test for survival end points. RESULTS: One hundred sixty-five patients were randomly assigned to the short-term (n = 82) or long-term (n = 83) maintenance arms. Because of the low event rate, the final analysis was performed after 95 events had occurred, which was before the targeted event number of 99 had been reached. At a median follow-up period of 6.4 years, the median EFS was 3.4 years (95% CI, 2.1 to 5.3) in the short-term arm and 5.3 years (95% CI, 3.5 to not available) in the long-term arm (P = .14). Patients in the long-term arm experienced more adverse effects than did those in the short-term arm, with 76% v 50% of patients with at least one adverse event (P < .001), five versus one patient with grade 3 and 4 infections, and three versus zero patients discontinuing treatment because of unacceptable toxicity, respectively. There was no difference in OS between the two groups. CONCLUSION: Long-term rituximab maintenance therapy does not improve EFS, which was the primary end point of this trial, or OS, and was associated with increased toxicity.

Final Results of a Prospective Evaluation of the Predictive Value of Interim Positron Emission Tomography in Patients With Diffuse Large B-Cell Lymphoma Treated With R-CHOP-14 (SAKK 38/07).

PURPOSE: Our main objective was to prospectively determine the prognostic value of [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) after two cycles of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone given every 14 days (R-CHOP-14) under standardized treatment and PET evaluation criteria. PATIENTS AND METHODS: Patients with any stage of diffuse large B-cell lymphoma were treated with six cycles of R-CHOP-14 followed by two cycles of rituximab. PET/CT examinations were performed at baseline, after two cycles (and after four cycles if the patient was PET-positive after two cycles), and at the end of treatment. PET/CT examinations were evaluated locally and by central review. The primary end point was event-free survival at 2 years (2-year EFS). RESULTS: Median age of the 138 evaluable patients was 58.5 years with a WHO performance status of 0, 1, or 2 in 56%, 36%, or 8% of the patients, respectively. By local assessment, 83 PET/CT scans (60%) were reported as positive and 55 (40%) as negative after two cycles of R-CHOP-14. Two-year EFS was significantly shorter for PET-positive compared with PET-negative patients (48% v 74%; P = .004). Overall survival at 2 years was not significantly different, with 88% for PET-positive versus 91% for PET-negative patients (P = .46). By using central review and the Deauville criteria, 2-year EFS was 41% versus 76% (P < .001) for patients who had interim PET/CT scans after two cycles of R-CHOP-14 and 24% versus 72% (P < .001) for patients who had PET/CT scans at the end of treatment. CONCLUSION: Our results confirmed that an interim PET/CT scan has limited prognostic value in patients with diffuse large B-cell lymphoma homogeneously treated with six cycles of R-CHOP-14 in a large prospective trial. At this point, interim PET/CT scanning is not ready for clinical use to guide treatment decisions in individual patients.

Stimulation of monocytes by placental microparticles involves toll-like receptors and nuclear factor kappa-light-chain-enhancer of activated B cells.

Human pregnancy is accompanied by a mild systemic inflammatory response, which includes the activation of monocytes circulating in maternal blood. This response is exaggerated in preeclampsia, a placental-dependent disorder specific to human pregnancies. We and others showed that placental syncytiotrophoblast membrane microparticles (STBM) generated in vitro from normal placentas stimulated peripheral blood monocytes, which suggest a contribution of STBM to the systemic maternal inflammation. Here, we analyzed the inflammatory potential of STBM prepared from preeclamptic placentas on primary monocytes and investigated the mode of action in vitro. STBM generated in vitro by placental villous explants of normal or preeclamptic placentas were co-incubated with human peripheral blood monocytes. In some cases, inhibitors of specific cellular functions or signaling pathways were used. The analysis of the monocytic response was performed by flow cytometry, enzyme-linked immunoassays, real-time PCR, and fluorescence microscopy. STBM derived from preeclamptic placentas up-regulated the cell surface expression of CD54, and stimulated the secretion of the pro-inflammatory interleukin (IL)-6 and IL-8 in a similar, dose-dependent manner as did STBM prepared from normal placentas. STBM bound to the cell surface of monocytes, but phagocytosis was not necessary for activation. STBM-induced cytokine secretion was impaired in the presence of inhibitors of toll-like receptor (TLR) signaling or when nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation was blocked. Our results suggest that the inflammatory reaction in monocytes may be initiated by the interaction of STBM with TLRs, which in turn signal through NF-κB to mediate the transcription of genes coding for pro-inflammatory factors.

Can detection of late-onset PE at triage by sflt-1 or PlGF be improved by the use of additional biomarkers?

OBJECTIVE: Accurate identification of preeclampsia (PE) at triage is essential to reduce maternal and fetal morbidity and mortality. The use of maternal blood based biomarkers may facilitate the clinician's ability to assess high risk pregnancies at triage. METHODS: A prospective cross-sectional study was performed to investigate the value of soluble fms-like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng), placental growth factor (PlGF), sP-selectin, cell-free fetal DNA and total cell-free DNA in patients with late-onset PE versus gestational age-matched controls. RESULTS: The diagnosis of late-onset PE (n = 21) at triage was significantly improved by altered levels of sFlt-1, sEng, PlGF and cffDNA as compared with controls (n = 42). Areas under the receiver operating characteristic curves [AUC, Standard error (SE)] for predicting PE were for marker measurements prior to the first stage of labor as follows: sFlt-1 0.97 (SE 0.02), sEng 0.91 (SE 0.04), PlGF 0.95 (SE 0.04), cell-free fetal DNA (DYS 14) 0.84 (SE 0.06), total cell-free DNA (glyceraldehyde 3-phosphate dehydrogenase) 0.61 (SE 0.07), sP-selectin 0.51 (SE 0.07). The discrimination could be slightly improved by using the slt1-PlGF ratio: 0.98 (SE 0.02). CONCLUSION: The sFlt-1 is a useful tool for the detection of late-onset PE at triage. This can be slightly improved using a sFlt-1/PIGF ratio. The addition of other biomarkers did not improve screening performance for late-onset PE.

Placental microparticles, DNA, and RNA in preeclampsia.

Preeclampsia is a common disorder of the second half of pregnancy that complicates 2% to 7% of all pregnancies worldwide and remains a major cause of maternal and fetal morbidity and mortality. Although the origin of the disease is still elusive, population-based studies have suggested that it might implicate genetic, immunologic, or physiologic factors. On the other hand, there is no doubt that the placenta plays an important role in its development. In preeclampsia, the shedding of placenta debris, such as syncytiotrophoblast microparticles (STBMs) and DNA and messenger RNA molecules, into the maternal peripheral blood is increased. The analysis of this material may give new insight into placentation and the underlying etiology of this disorder, as well as yield new tracks of research for the understanding of the molecular mechanisms, leading to the generation of the clinical symptoms.

Detection of increased amounts of cell-free fetal DNA with short PCR amplicons.

AIM: A digital PCR approach has recently been suggested to detect greater amounts of cell-free fetal DNA in maternal plasma than conventional real-time quantitative PCR (qPCR). Because the digital qPCR approach uses shorter PCR amplicons than the real-time qPCR assay, we investigated whether a real-time qPCR assay appropriately modified for such short amplicons would improve the detection of cell-free fetal DNA. METHOD: We developed a novel universal-template (UT) real-time qPCR assay that was specific for the DYS14 sequence on Y chromosome and had a short amplicon size of 50 bp. We examined this "short" assay with 50 maternal plasma samples and compared the results with those for a conventional real-time qPCR assay of the same locus but with a longer amplicon (84 bp). RESULTS: Qualitatively, both assays detected male cell-free fetal DNA with the same specificity and detection capability. Quantitatively, however, the new UT real-time qPCR assay for shorter amplicons detected, on average, almost 1.6-fold more cell-free fetal DNA than the conventional real-time qPCR assay with longer amplicons. CONCLUSIONS: The use of short PCR amplicons improves the detection of cell-free fetal DNA. This feature may prove useful in attempts to detect cell-free fetal DNA under conditions in which the amount of template is low, such as in samples obtained early in pregnancy.

Potential markers of preeclampsia--a review.

Preeclampsia is a leading cause of maternal and fetal/neonatal mortality and morbidity worldwide. The early identification of patients with an increased risk for preeclampsia is therefore one of the most important goals in obstetrics. The availability of highly sensitive and specific physiologic and biochemical markers would allow not only the detection of patients at risk but also permit a close surveillance, an exact diagnosis, timely intervention (e.g. lung maturation), as well as simplified recruitment for future studies looking at therapeutic medications and additional prospective markers. Today, several markers may offer the potential to be used, most likely in a combinatory analysis, as predictors or diagnostic tools. We present here the current knowledge on the biology of preeclampsia and review several biochemical markers which may be used to monitor preeclampsia in a future, that, we hope, is not to distant from today.

PLAC4 and beta-HCG mRNA levels are not altered in the maternal circulation of pregnancies with trisomy 21.

OBJECTIVE: Beta-human chorionic gonadotropin (HCG) and pregnancy-associated plasma protein (PAPP-A) are placentally produced proteins whose levels are altered in pregnancies with trisomy 21. PLAC4 is located on chromosome 21 and its expression is restricted to the placenta. Here we investigated whether the levels of beta-HCG-, PAPP-A- and PLAC4 mRNA could be able to discriminate pregnancies whose fetus is affected by trisomy 21. METHOD: Hundred and forty-three blood samples from normal pregnancies and eight samples from trisomic pregnancies were collected. Total RNA was extracted from whole maternal blood, reverse-transcribed and the three mRNAs were quantified by real-time quantitative PCR. Hundred and nine controls were also tested for the serum levels of PAPP-A and HCG proteins. RESULTS: Beta-HCG and PLAC4 mRNAs were detected in all samples, in higher amounts than in plasma, whereas the detection rate for PAPP-A mRNA was below 10%. The levels of beta-HCG mRNA significantly correlated with the circulatory concentrations of the HCG protein. However, neither beta-HCG- nor PLAC4 mRNAs show a significant difference between cases and controls. CONCLUSION: Maternal blood levels of beta-HCG-, PLAC4- and PAPP-A mRNAs are not useful markers for the screening of pregnancies with trisomy 21 as their concentrations are either not significantly altered (beta-HCG and PLAC4) or too low to be detected (PAPP-A).

Isolation of serum nucleic acids for fetal DNA analysis: comparison of manual and automated extraction methods.

OBJECTIVES: To investigate the performance of an automated system for the extraction of cell-free DNA of maternal and fetal origin from stored serum samples for subsequent quantitative real-time polymerase chain reaction (PCR) analysis. METHODS: Thirty-two maternal blood samples between the early second trimester and term were obtained. Cell-free DNA was extracted from replicate stored sera using a column-based manual isolation procedure and with an automated system, the MagNA Pure LC Instrument. Real-time quantitative PCR for the ubiquitous glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and male-specific DYS14 loci was performed. RESULTS: The extraction yields for both total and fetal DNA and the quality of the purified nucleic acids were similar for the automated system or the manual procedure. However, the number of false-negative results in samples collected early in pregnancy was reduced with the automated extraction. Furthermore, the extraction rate by the automated system was highly reproducible over time. CONCLUSIONS: We validated the use of an automated extraction system for the isolation of fetal DNA from stored serum. This procedure might be exploited in the future for high-throughput non-invasive fetal gene analysis of archived serum samples.

Role of placentally produced inflammatory and regulatory cytokines in pregnancy and the etiology of preeclampsia.

Human pregnancy is a metabolic and immune challenge for the mother who has to accommodate in her womb a semi-allogeneic fetus whose energy needs increase tremendously with gestation. Recent compelling research has suggested that proper inflammatory changes and oxidative balance are a requisite for successful pregnancy. The placenta is an integral component of this inflammatory response as it actively produces a variety of cytokines and immunomodulatory hormones. In preeclampsia, a life-threatening disorder of pregnancy that is characterized by widespread damage and dysfunction of the maternal endothelium, placental oxidative stress and aberrant cytokine expression induces an exaggerated maternal systemic inflammatory response to pregnancy.

The chromatin of differentiating erythroblasts is cleaved into large size fragments independent of caspase activated DNase and apoptosis inducing factor.

Erythroblast cell differentiation involves self-controlled and limited nuclear proteolysis prior nucleus loss. Early evidence suggests that apoptotic-like pathways are activated during this process. The chromatin of developing erythroblasts becomes fragmented in vivo, however, the exact mechanisms and molecules involved remain elusive. In this study, erythroblasts were differentiated in culture from CD34-enriched umbilical cord blood progenitor cells and the characteristics of DNA fragmentation were examined. This analysis shows that the chromatin of differentiating erythroblasts is cleaved into discrete fragments of 50-200 kb. This process most likely involves one or several endonucleases as we detect in vivo double strand DNA cleavage. However, major players of the apoptotic DNA degradation, caspase activated DNase and apoptosis inducing factor, are not activated in these cells. Therefore, our data suggests that erythroblast chromatin degradation may involve enzymes distinct form those active in apoptotic cells.

Oxidative stress alters the integrity of cell-free mRNA fragments associated with placenta-derived syncytiotrophoblast microparticles.

OBJECTIVES: Cell-free fetal RNA from placental origin is present in the peripheral blood of pregnant women. Therefore, its qualitative analysis might provide insights into the physiological condition of the placenta. Here, we examine whether oxidative stress affects the integrity of placentally derived mRNA in vitro. METHODS: Placental explants were cultured under normal or oxidative conditions, and the levels of placental and syncytiotrophoblast microparticle associated glyceraldehyde-3-phosphate dehydrogenase 3' versus 5' mRNA fragments were analyzed by real-time reverse-transcriptase polymerase chain reaction. RESULT: The relative ratio of 3' to 5' mRNA fragments associated with placental microparticles was significantly altered upon culture under oxidative stress. CONCLUSIONS: Our data suggest that oxidative stress reduces the levels of full-length, particle-associated glyceraldehyde-3-phosphate dehydrogenase mRNA transcripts released by the placenta. Therefore, analysis of the microparticle-coupled mRNA integrity in pregnant women might prove useful to diagnose disorders such as preeclampsia, where placental oxidative stress is involved.

Human mature erythroblasts are resistant to apoptosis.

Apoptosis plays an important role in red blood cell development, notably by regulating the fate of early erythroid progenitors. We show here that, by contrast, mature erythroblasts are resistant to apoptosis. Treatment of these cells with several apoptosis-inducing agents failed to trigger caspase activation and oligonucleosomal DNA fragmentation. Interestingly, we find that cytochrome c levels are dramatically reduced even though the cells contain mitochondria. Supplementation of cytosolic extracts from mature erythroblasts with cytochrome c, however, did not rescue caspase activation. This was not due to the presence of inhibitors of apoptosis, as these proteins were also missing in these cells. We also show that cytochrome c depletion is a normal event during erythroblast differentiation, which follows transient, developmentally induced caspase activation and correlates with the loss of response to cytokine withdrawal or drug-induced apoptosis. Our data therefore suggest that erythroblasts acquire resistance to apoptosis during maturation through the developmentally induced depletion of cytochrome c and other crucial regulators of the apoptotic machinery.

Ectopic expression of PAX5 promotes maintenance of biphenotypic myeloid progenitors coexpressing myeloid and B-cell lineage-associated genes.

The transcription factor PAX5 is a critical regulator of B-cell commitment and development. Although normally not expressed in myeloid progenitors, PAX5 has recently been shown to be frequently expressed in myeloid malignancies and to suppress expression of myeloid differentiation genes, compatible with an effect on the differentiation or maintenance of myeloid progenitors. However, previous studies in which PAX5 was ectopically expressed in normal myeloid progenitors in vivo and in vitro provided conflicting results as to the effect of PAX5 on myeloid development. Herein, we demonstrate that on ectopic expression of PAX5 in bone marrow multipotent stem/progenitor cells, cells with a biphenotypic B220(+)GR-1/MAC-1(+) phenotype are produced. These remain cytokine-dependent, but unlike control-transduced cells they sustain long-term generation of myeloid progenitors in vitro and remain capable of myeloid differentiation. Notably, PAX5(+)B220(+)GR-1/MAC-1(+) myeloid progenitors coexpress, at the single-cell level, myeloid genes and otherwise B-cell-specific PAX5 target genes. These findings establish that ectopic expression of PAX5 introduces extensive self-renewal properties in otherwise short-lived myeloid progenitors. Along with the established ectopic expression of PAX5 in acute myeloid leukemia, this motivates a careful investigation of the potential involvement of ectopic PAX5 expression in myeloid and biphenotypic leukemias.

Disturbances in placental immunology: ready for therapeutic interventions?

Recent studies have provided new insight into aberrations in the immunological interplay between mother and fetus and their potential role in the development of recurrent fetal loss and preeclampsia. The action of anti-phospholipid antibodies in recurrent fetal loss is now proposed to involve the complement system, neutrophil activation and the production of TNFalpha by immune bystander cells. A clear involvement of the immune system is emerging in preeclampsia, involving mainly the innate arm, especially neutrophils. The activation of peripheral neutrophils by placentally released inflammatory debris triggers the induction of neutrophil extracellular traps (NETs), which may lead to an occlusion of the intervillous space, thereby further promoting a condition of placental hypoxia. It has, hence, been suggested that new therapeutic strategies be developed, including the possible use of TNFalpha antagonists in cases of recurrent miscarriage. These strategies need to be addressed with caution due to the possible induction of fetal congenital abnormalities.

Syncytiotrophoblast micro-particles do not induce apoptosis in peripheral T lymphocytes, but differ in their activity depending on the mode of preparation.

Recent studies have suggested that pre-eclampsia may result from endothelial cell damage and overt immune activity triggered by the elevated release of syncytiotrophoblast-derived micro-particles (STBM). In this context, STBM have been reported to inhibit lymphocyte proliferation and induce Jurkat T cell apoptosis. In this study, STBM were prepared by three different in vitro methods (mechanical dissection, villous explant culture, and placental perfusion) and their functional properties were tested on T lymphocytes enriched from peripheral blood samples. Mechanically- and villous explant-derived STBM significantly inhibited activation, proliferation and cytokine release by T lymphocytes, while placental perfusion-derived STBM significantly induced T cell proliferation and a slight increase in IFNgamma release. None of the STBM preparations caused T cell apoptosis. Therefore, STBM prepared by different methods in vitro exhibit different effects on circulating T cells, a feature that will have to be taken into account when considering their potential role in normal pregnancy and pre-eclampsia.

Soluble factors released by placental villous tissue: Interleukin-1 is a potential mediator of endothelial dysfunction.

OBJECTIVE: The purpose of this study was to analyze the potential of placental-conditioned medium to activate endothelial cells in vitro and to identify the placental factors that mediate this effect. STUDY DESIGN: Placental-conditioned medium was generated by the culturing of normal term placental villous explants for up to 48 hours. Human umbilical vein endothelial cells were exposed to the conditioned media, and cellular proliferation, viability, and activation were investigated. RESULTS: The proliferation of endothelial cells that were exposed to 20% placental-conditioned medium was reduced by 25%, but their survival was not compromised. Conditioned medium also up-regulated the expression of E-selectin and stimulated the release of soluble intercellular adhesion molecule-1 and the secretion of interleukin-6. Treatment with interleukin-1 receptor antagonist, but not with an anti-tumor necrosis factor-alpha neutralizing antibody, blocked the release of soluble intercellular adhesion molecule-1 and interleukin-6. CONCLUSION: Placentally derived interleukin-1 may be 1 of the potential mediators of the maternal inflammatory response that is observed in late pregnancy.