Functional Characterization of Transforming Growth Factor-β Signaling in Dasatinib Resistance and Pre-BCR+ Acute Lymphoblastic Leukemia

The multi-kinase inhibitor dasatinib has been implicated to be effective in pre-B-cell receptor (pre-BCR)-positive acute lymphoblastic leukemia (ALL) expressing the E2A-PBX1 fusion oncoprotein. The TGFβ signaling pathway is involved in a wide variety of cellular processes, including embryonic development and cell homeostasis, and it can have dual roles in cancer: suppressing tumor growth at early stages and mediating tumor progression at later stages. In this study, we identified the upregulation of the TGFβ signaling pathway in our previously generated human dasatinib-resistant pre-BCR+/E2A-PBX1+ ALL cells using global transcriptomic analysis. We confirm the upregulation of the TGFβ pathway member SMAD3 at the transcriptional and translational levels in dasatinib-resistant pre-BCR+/E2A-PBX1+ ALL cells. Hence, dasatinib blocks, at least partially, TGFβ-induced SMAD3 phosphorylation in several B-cell precursor (BCP) ALL cell lines as well as in dasatinib-resistant pre-BCR+/E2A-PBX1+ ALL cells. Activation of the TGFβ signaling pathway by TGF-β1 leads to growth inhibition by cell cycle arrest at the G0/G1 stage, increase in apoptosis and transcriptional changes of SMAD-targeted genes, e.g. c-MYC downregulation, in pre-BCR+/E2A-PBX1+ ALL cells. These results provide a better understanding about the role that the TGFβ signaling pathway plays in leukemogenesis of BCP-ALL as well as in secondary drug resistance to dasatinib.

Effects of Vitamin D Supplementation on Telomere Length: An Analysis of Data from the Randomised Controlled D-Health Trial

OBJECTIVES

Observational studies have suggested that a higher 25-hydroxyvitamin D concentration may be associated with longer telomere length; however, this has not been investigated in randomised controlled trials. We conducted an ancillary study within a randomised, double-blind, placebo-controlled trial of monthly vitamin D (the D-Health Trial) for the prevention of all-cause mortality, conducted from 2014 to 2020, to assess the effect of vitamin D supplementation on telomere length (measured as the telomere to single copy gene (T/S) ratio).

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION

Participants were Australians aged 60-84 years and we randomly selected 1,519 D-Health participants (vitamin D: n=744; placebo: n=775) for this analysis. We used quantitative polymerase chain reaction to measure the relative telomere length (T/S ratio) at 4 or 5 years after randomisation. We compared the mean T/S ratio between the vitamin D and placebo groups to assess the effect of vitamin D supplementation on relative telomere length, using a linear regression model with adjustment for age, sex, and state which were used to stratify the randomisation.

RESULTS

The mean T/S ratio was 0.70 for both groups (standard deviation 0.18 and 0.16 for the vitamin D and placebo groups respectively). The adjusted mean difference (vitamin D minus placebo) was -0.001 (95% CI -0.02 to 0.02). There was no effect modification by age, sex, body mass index, or predicted baseline 25-hydroxyvitamin D concentration.

CONCLUSION

In conclusion, routinely supplementing older adults, who are largely vitamin D replete, with monthly doses of vitamin D is unlikely to influence telomere length.

Monitoring of Measurable Residual Disease Using Circulating DNA after Allogeneic Hematopoietic Cell Transplantation

Simple Summary

The major cause of treatment failure after allogeneic stem cell transplantation (allo-HSCT) is due to relapse of the underlying disease. Novel methods and strategies are needed to detect early relapse after allo-HSCT. The present study reports the clinical utility of monitoring measurable residual disease (MRD) and mixed chimerism (MC) by droplet-digital PCR in circulating cell-free DNA (cfDNA) in 62 patients with myeloid malignancies undergoing allo-HSCT. MC in circulating cfDNA at an optimal threshold of 18% discriminated patients with hematological relapse from patients in complete remission after allo-HSCT. Most of the mutations identified using a targeted next-generation sequencing (NGS) panel were detected in cfDNA at relapse and were suitable for the monitoring of MRD. In several cases, mutations were detected earlier in cfDNA than in peripheral blood mononuclear cells. In conclusion, longitudinal analysis of cfDNA for MRD and MC can be used as a complementary tool for early detection of relapse in patients after allo-HSCT and could be used to guide clinical interventions.

Abstract

Relapse of the underlying disease is a frequent complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). In this study, we describe the clinical utility of measurable residual disease (MRD) and mixed chimerism (MC) assessment in circulating cell-free DNA (cfDNA) analysis to detect earlier relapse in patients with hematological malignancies after allo-HSCT. A total of 326 plasma and peripheral blood mononuclear cell (PBMCs) samples obtained from 62 patients with myeloid malignancies were analyzed by droplet-digital PCR (median follow-up: 827 days). Comparison of MC in patients at relapse and in complete remission identified an optimal discriminating threshold of 18% of recipient-derived cfDNA. After performing a targeted next-generation sequencing (NGS) panel, 136 mutations in 58 patients were detected. In a total of 119 paired samples, the putative mutations were detected in both cfDNA and PBMCs in 73 samples (61.3%). In 45 samples (37.8%) they were detected only in cfDNA, and in only one patient (0.9%) were they detected solely in DNA from PBMCs. Hence, in 6 out of 23 patients (26%) with relapse after allo-HSCT, MRD positivity was detected earlier in cfDNA (mean 397 days) than in DNA derived from PBMCs (mean 451 days). In summary, monitoring of MRD and MC in cfDNA might be useful for earlier relapse detection in patients with myeloid malignancies after allo-HSCT.

First-in-human study of WT1 recombinant protein vaccination in elderly patients with AML in remission: a single-center experience

Wilms’ tumor 1 (WT1) protein is highly immunogenic and overexpressed in acute myeloid leukemia (AML), consequently ranked as a promising target for novel immunotherapeutic strategies. Here we report our experience of a phase I/II clinical trial (NCT01051063) of a vaccination strategy based on WT1 recombinant protein (WT1-A10) together with vaccine adjuvant AS01_B in five elderly AML patients (median age 69 years, range 63–75) receiving a total of 62 vaccinations (median 18, range 3–20) after standard chemotherapy. Clinical benefit was observed in three patients: one patient achieved measurable residual disease clearance during WT1 vaccination therapy, another patient maintained long-term molecular remission over 59 months after the first vaccination cycle. Interestingly, in one case, we observed a complete clonal switch at AML relapse with loss of WT1 expression, proposing suppression of the original AML clone by WT1-based vaccination therapy. Detected humoral and cellular CD4⁺ T cell immune responses point to efficient immune stimulation post-vaccination, complementing hints for induced conventional T cell infiltration into the bone marrow and a shift from senescent/exhausted to a more activated T cell profile. Overall, the vaccinations with WT1 recombinant protein had an acceptable safety profile and were thus well tolerated.

To conclude, our data provide evidence of potential clinical efficacy of WT1 protein-based vaccination therapy in AML patients, warranting further investigations.

The impact of pulmonary function in patients undergoing autologous stem cell transplantation

High-dose chemotherapy, followed by autologous hematopoietic stem cell transplantation (auto-HSCT), is an established therapy for patients with hematological malignancies. The age of patients undergoing auto-HSCT and, therefore, the comorbidities, has increased over the last decades. However, the assessment of organ dysfunction prior to auto-HSCT has not been well studied. Therefore, we retrospectively analyzed the association of clinical factors and lung and cardiac function with outcome and complications after conditioning with BEAM (BCNU/carmustine, etoposide, cytarabine, melphalan) or high-dose melphalan in patients undergoing auto-HSCT. This study included 629 patients treated at our institution between 2007 and 2017; 334 and 295 were conditioned with BEAM or high-dose melphalan, respectively. The median follow-up was 52 months (range, 0.2-152) and 50 months (range, 0.5-149), respectively. In the multivariate analysis, we identified that progressive disease, CO-diffusion capacity corrected for hemoglobin (DLCOcSB) ≤ 60% of predicted, Karnofsky Performance Status (KPS) ≤ 80%, Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) score ≥ 4, and age > 70 years were associated with decreased overall survival (OS) in patients treated with BEAM. Similarly, DLCOcSB ≤ 60% of predicted, HCT-CI score ≥ 4, and age > 60 years were identified in patients treated with high-dose melphalan. Abnormalities in DLCOcSB ≤ 60% of predicted were associated with chemotherapy with lung-toxic substances, mediastinal radiotherapy, KPS ≤ 80%, current/previous smoking, and treatment in the intensive care unit. More often, patients with DLCOcSB ≤ 60% of predicted experienced nonrelapse mortality, including pulmonary causes of death. In summary, we identified DLCOcSB ≤ 60% of predicted as an independent risk factor for decreased OS in patients conditioned with BEAM or high-dose melphalan prior to auto-HSCT.

Murine Oncostatin M Has Opposing Effects on the Proliferation of OP9 Bone Marrow Stromal Cells and NIH/3T3 Fibroblasts Signaling through the OSMR

The IL-6 family cytokine Oncostatin M (OSM) is involved in cell development, growth, hematopoiesis, inflammation, and cancer. Intriguingly, OSM has proliferative and antiproliferative effects depending on the target cell. The molecular mechanisms underlying these opposing effects are not fully understood. Previously, we found OSM upregulation in different myeloproliferative syndromes. However, OSM receptor (OSMR) expression was detected on stromal cells but not the malignant cells themselves. In the present study, we, therefore, investigated the effect of murine OSM (mOSM) on proliferation in stromal and fibroblast cell lines. We found that mOSM impairs the proliferation of bone marrow (BM) stromal cells, whereas fibroblasts responded to mOSM with increased proliferation. When we set out to reveal the mechanisms underlying these opposing effects, we detected increased expression of the OSM receptors OSMR and LIFR in stromal cells. Interestingly, Osmr knockdown and Lifr overexpression attenuated the OSM-mediated effect on proliferation in both cell lines indicating that mOSM affected the proliferation signaling mainly through the OSMR. Furthermore, mOSM induced activation of the JAK-STAT, PI3K-AKT, and MAPK-ERK pathways in OP9 and NIH/3T3 cells with differences in total protein levels between the two cell lines. Our findings offer new insights into the regulation of proliferation by mOSM.

Donor lymphocyte infusions after first allogeneic hematopoietic stem-cell transplantation in adults with acute myeloid leukemia: a single-center landmark analysis

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is potentially curative for acute myeloid leukemia (AML). The inherent graft-versus-leukemia activity (GvL) may be optimized by donor lymphocyte infusions (DLI). Here we present our single-center experience of DLI use patterns and effectiveness, based on 342 consecutive adult patients receiving a first allo-HSCT for AML between 2009 and 2017. The median age at transplantation was 57 years (range 19-79), and the pre-transplant status was active disease in 58% and complete remission (CR) in 42% of cases. In a combined landmark analysis, patients in CR on day +30 and alive on day +100 were included. In this cohort (n=292), 93 patients received cryopreserved aliquots of peripheral blood-derived grafts for DLI (32%) and median survival was 55.7 months (2-year/5-year probability: 62%/49%). Median survival for patients receiving a first dose of DLI "preemptively," in the absence of relapse and guided by risk marker monitoring (preDLI; n=42), or only after hematological relapse (relDLI; n=51) was 40.9 months (2-year/5-year: 64%/43%) vs 10.4 months (2-year/5-year: 26%/10%), respectively. Survival was inferior when preDLI was initiated at a time of genetic risk marker detection vs mixed chimerism or clinical risk only. Time to first-dose preDLI vs time to first-dose relDLI was similar, suggesting that early warning and intrinsically lower dynamics of AML recurrence may contribute to effectiveness of preDLI-modified GvL activity. Future refinements of the preemptive DLI concept will benefit from collaborative efforts to diagnose measurable residual disease more reliably across the heterogeneous genomic spectrum of AML.

Colon and liver tissue damage detection using methylated SESN3 and PTK2B genes in circulating cell-free DNA in patients with acute graft-versus-host disease

Cell-free DNA (cfDNA) has been investigated in acute graft-versus-host disease (aGvHD) following allogeneic cell transplantation (HSCT). Identifying the tissue of origin of cfDNA in patients with aGvHD is relevant particularly when a biopsy is not feasible. We investigate the cfDNA tissue of origin in patients with aGvHD using methylated gene biomarkers. Patients with liver, colon, or skin aGvHD (n = 28) were analyzed. Liver- and colon-derived cfDNA was measured using a colon- (SESN3) and liver (PTK2B)-specific methylation marker with digital droplet PCR. A statistically significant difference (p < 0.001) in PTK2B and SESN3 concentration was observed between patients with colon or liver GvHD and the control group. For SESN3 and PTK2B the area under the curve in the receiver-operating characteristic (ROC) space was 0.952 (95% CI, 0.888–1 p < 0.001) and 0.971 (95% CI, 0.964–1 p < 0.001), respectively. Thresholds to differentiate aGvHD from non-aGvHD in colon were 0 (sensitivity: 0.905; specificity: 0.989) and liver 1.5 (sensitivity: 0.928; specificity: 0.910). Clinical improvement of liver or colon aGvHD resulted in PTK2B and SESN3 reduced concentration. Whereas, in those patients without improvement the PTK2B and SESN3 level remained stable or increased. The PTK2B liver-specific marker and the SESN3 colon-specific marker and their longitudinal analysis might improve aGvHD detection.

Droplet digital PCR for the simultaneous analysis of minimal residual disease and hematopoietic chimerism after allogeneic cell transplantation

Background Minimal residual disease (MRD) and hematopoietic chimerism testing influences clinical decision and therapeutic intervention in patients after allogeneic stem cell transplantation (HSCT). However, treatment approaches to induce complete donor chimerism and MRD negativity can lead to complications such as graft-versus-host disease (GvHD) and marrow aplasia. Therefore, there is a need for comprehensive characterization of the molecular remission status after transplantation. Methods We analyzed 764 samples from 70 patients after HSCT for the simultaneous measurement of chimerism and molecular targets used for MRD testing with a digital PCR (dPCR) platform. Results Mixed chimerism (MC) was detected in 219 samples from 37 patients. The mean percentage of host derived DNA in these clinical samples was 4.3%. Molecular relapse with a positive MRD marker and/or increased WT1 expression was observed in 15 patients. In addition to WT1 overexpression, other MRD positive markers were: NPM1 (Type A, B, K), DNMT3A (R882H), MLL-PTD, IDH1 (R132H) and KRAS (G12S). Increasing MC was observed in 15 patients. This group of patients showed either a positive MRD marker, increased WT1 expression or both. Next, we analyzed whether MC or the molecular target for MRD was first detected. MC and MRD marker positivity in this group was first detected in six and two patients, respectively. In the remaining seven patients MC and MRD positivity was detected simultaneously. Conclusions The combination of MRD and chimerism markers in a dPCR platform represents a practical, sensitive and accurate diagnostic tool for the comprehensive assessment of the molecular remission status of patients undergoing HSCT.

The effect of sunscreen on vitamin D: a review

BACKGROUND

Sunscreen use can prevent skin cancer, but there are concerns that it may increase the risk of vitamin D deficiency.

OBJECTIVES

We aimed to review the literature to investigate associations between sunscreen use and vitamin D₃ or 25 hydroxyvitamin D [25(OH)D] concentration.

METHODS

We systematically reviewed the literature following the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. We identified manuscripts published in English between 1970 and 21 November 2017. Eligible studies were experimental [using an artificial ultraviolet radiation (UVR) source], field trials or observational studies. The results of each of the experimental studies and field trials are described in detail. Two authors extracted information from observational studies, and applied quality scoring criteria that were developed specifically for this question. These have been synthesized qualitatively.

RESULTS

We included four experimental studies, three field trials (two were randomized controlled trials) and 69 observational studies. In the experimental studies sunscreen use considerably abrogated the vitamin D₃ or 25(OH)D production induced by exposure to artificially generated UVR. The randomized controlled field trials found no effect of daily sunscreen application, but the sunscreens used had moderate protection [sun protection factor SPF) ~16]. The observational studies mostly found no association or that self-reported sunscreen use was associated with higher 25(OH)D concentration.

CONCLUSIONS

There is little evidence that sunscreen decreases 25(OH)D concentration when used in real-life settings, suggesting that concerns about vitamin D should not negate skin cancer prevention advice. However, there have been no trials of the high-SPF sunscreens that are now widely recommended. What's already known about this topic? Previous experimental studies suggest that sunscreen can block vitamin D production in the skin but use artificially generated ultraviolet radiation with a spectral output unlike that seen in terrestrial sunlight. Nonsystematic reviews of observational studies suggest that use in real life does not cause vitamin D deficiency. What does this study add? This study systematically reviewed all experimental studies, field trials and observational studies for the first time. While the experimental studies support the theoretical risk that sunscreen use may affect vitamin D, the weight of evidence from field trials and observational studies suggests that the risk is low. We highlight the lack of adequate evidence regarding use of the very high sun protection factor sunscreens that are now recommended and widely used.

Immune signature drives leukemia escape and relapse after hematopoietic cell transplantation

Transplantation of hematopoietic cells from a healthy individual (allogeneic hematopoietic cell transplantation (allo-HCT)) demonstrates that adoptive immunotherapy can cure blood cancers: still, post-transplantation relapses remain frequent. To explain their drivers, we analyzed the genomic and gene expression profiles of acute myeloid leukemia (AML) blasts purified from patients at serial time-points during their disease history. We identified a transcriptional signature specific for post-transplantation relapses and highly enriched in immune-related processes, including T cell costimulation and antigen presentation. In two independent patient cohorts we confirmed the deregulation of multiple costimulatory ligands on AML blasts at post-transplantation relapse (PD-L1, B7-H3, CD80, PVRL2), mirrored by concomitant changes in circulating donor T cells. Likewise, we documented the frequent loss of surface expression of HLA-DR, -DQ and -DP on leukemia cells, due to downregulation of the HLA class II regulator CIITA. We show that loss of HLA class II expression and upregulation of inhibitory checkpoint molecules represent alternative modalities to abolish AML recognition from donor-derived T cells, and can be counteracted by interferon-γ or checkpoint blockade, respectively. Our results demonstrate that the deregulation of pathways involved in T cell-mediated allorecognition is a distinctive feature and driver of AML relapses after allo-HCT, which can be rapidly translated into personalized therapies.

Impact of Lung Function on Bronchiolitis Obliterans Syndrome and Outcome after Allogeneic Hematopoietic Cell Transplantation with Reduced-Intensity Conditioning

Lung function deterioration contributes to treatment-related morbidity and mortality in patients after allogeneic hematopoietic cell transplantation (allo-HCT). Better understanding of impaired lung function including bronchiolitis obliterans syndrome (BOS) as chronic manifestation of graft-versus-host disease (GVHD) might improve outcomes of patients after allo-HCT. To detect early pulmonary function test abnormalities associated with BOS incidence and outcome after allo-HCT, we performed a retrospective analysis of homogenous-treated 445 patients (median age, 61.9 years; range, 19 to 76 years) with a reduced intensity/toxicity conditioning protocol. The cumulative incidence of BOS was 4.1% (95% confidence interval [CI], 2.6 to 6.4) at 1 year and 8.6% (95% CI, 6.3 to 11.6) at 5 years after allo-HCT with a median follow-up of 43.2 months (range, 3.3 to 209 months). In multivariate analysis, pre-existence of moderate small airway disease reflected by decreased midexpiratory flows before allo-HCT was associated with increased risk for BOS development. In addition, severe small airway disease before allo-HCT and combined restrictive/obstructive lung disease at day +100 after allo-HCT were associated with higher risk for nonrelapse mortality (NRM) due mainly to pulmonary cause of death. In summary, we identified novel pulmonary function test abnormalities prior and after allo-HCT associated with BOS development and NRM. These findings might help to identify a risk population and result in personalized GVHD prophylaxis and preventive or early therapeutic interventions.

Sorafenib promotes graft-versus-leukemia activity in mice and humans through IL-15 production in FLT3-ITD-mutant leukemia cells

Individuals with acute myeloid leukemia (AML) harboring an internal tandem duplication (ITD) in the gene encoding Fms-related tyrosine kinase 3 (FLT3) who relapse after allogeneic hematopoietic cell transplantation (allo-HCT) have a 1-year survival rate below 20%. We observed that sorafenib, a multitargeted tyrosine kinase inhibitor, increased IL-15 production by FLT3-ITD+ leukemia cells. This synergized with the allogeneic CD8+ T cell response, leading to long-term survival in six mouse models of FLT3-ITD+ AML. Sorafenib-related IL-15 production caused an increase in CD8+CD107a+IFN-γ+ T cells with features of longevity (high levels of Bcl-2 and reduced PD-1 levels), which eradicated leukemia in secondary recipients. Mechanistically, sorafenib reduced expression of the transcription factor ATF4, thereby blocking negative regulation of interferon regulatory factor 7 (IRF7) activation, which enhanced IL-15 transcription. Both IRF7 knockdown and ATF4 overexpression in leukemia cells antagonized sorafenib-induced IL-15 production in vitro. Human FLT3-ITD+ AML cells obtained from sorafenib responders following sorafenib therapy showed increased levels of IL-15, phosphorylated IRF7, and a transcriptionally active IRF7 chromatin state. The mitochondrial spare respiratory capacity and glycolytic capacity of CD8+ T cells increased upon sorafenib treatment in sorafenib responders but not in nonresponders. Our findings indicate that the synergism of T cells and sorafenib is mediated via reduced ATF4 expression, causing activation of the IRF7-IL-15 axis in leukemia cells and thereby leading to metabolic reprogramming of leukemia-reactive T cells in humans. Therefore, sorafenib treatment has the potential to contribute to an immune-mediated cure of FLT3-ITD-mutant AML relapse, an otherwise fatal complication after allo-HCT.

DNA chimerism and its consequences after allogeneic hematopoietic cell transplantation

The unphysiological formation of biological chimeras after allogeneic hematopoietic cell transplantation is not free of consequences. Recent findings suggest that in the transplant recipient some epithelial cells reveal, unexpectedly, donor-derived genotype and/or acquire genomic alterations. Since both phenomena are presented in the host epithelium, one could argue that they might be etiologically linked through a common background mechanism. We recently proposed that the incessant charge of the transplant recipient with donor-DNA and its integration in host epithelium by horizontal DNA transference may indeed be operative in the generation of epithelial cells with donor derived genome. On the other hand, the incessant incorporation of the foreign DNA into the host genome may result in genomic alterations. Lymphocyte-epithelial interactions between the two genetically distinct cell populations in the transplant recipient should be investigated more precisely not only in cellular but also in molecular level.

Early mixed hematopoietic chimerism detection by digital droplet PCR in patients undergoing gender-mismatched hematopoietic stem cell transplantation

Background:

Clinical decision making after allogeneic stem cell transplantation (HSCT) is partially based on hematopoietic chimerism analysis. Polymerase chain reaction amplification of polymorphic short tandem repeats (STR-PCR) is currently considered the gold standard for chimerism surveillance after transplantation. Nevertheless, this method has shown several limitations. Emerging technologies such as digital PCR (dPCR) has been applied to detect hematopoietic chimerism. Despite previous reports, the clinical usefulness of dPCR is unclear because the studies were performed in limited patient populations with short follow-ups.

Methods:

In order to compare hematopoietic chimerism detection time and rate, we analyzed 591 samples from 155 patients undergoing gender-mismatched HSCT using STR-PCR and dPCR. We also established the correlation between both methods in artificial DNA mixtures prepared in known proportions and in clinical samples.

Results:

Depending on the artificial DNA mixture analyzed the correlation coefficient between both methods was 0.9946 and 0.9732. The limit of detection for dPCR was 0.01%. Of 157 samples with donor and recipient DNA, mixed chimerism (MC) was detected solely by dPCR in 66 samples. Within the group of patients relapsing after HSCT (n=32) MC was detected earlier in 15 of these patients with dPCR in comparison with STR-PCR. The mean time from MC detection to relapse was 155 days (range: 13–385 days) and 65 days (range: 0–203 days) for dPCR and STR-PCR, respectively.

Conclusions:

dPCR is a sensitive and accurate method for the quantification of hematopoietic chimerism allowing earlier MC detection compared to STR-PCR.

Clinical outcomes following unilateral adrenalectomy in patients with primary aldosteronism

BACKGROUND

In approximately half of cases of primary aldosteronism (PA), the cause is a surgically-resectable unilateral aldosterone-producing adrenal adenoma. However, long-term data on surgical outcomes are sparse.

AIM

We report on clinical outcomes post-adrenalectomy in a cohort of patients with PA who underwent surgery.

DESIGN

Retrospective review of patients treated for PA in a single UK tertiary centre.

METHODS

Of 120 consecutive patients investigated for PA, 52 (30 male, median age 54, range 30-74) underwent unilateral complete adrenalectomy. Blood pressure, number of antihypertensive medications, and serum potassium were recorded before adrenalectomy, and after a median follow-up period of 50 months (range 7-115). Recumbent renin and aldosterone were measured, in the absence of interfering antihypertensive medication, ≥3months after surgery, to determine if PA had been biochemically cured.

RESULTS

Overall, blood pressure improved from a median (range) 160/95 mmHg (120/80-250/150) pre-operatively to 130/80 mmHg (110/70-160/93), P < 0.0001. 24/52 patients (46.2%) had cured hypertension, with a normal blood pressure post-operatively on no medication. 26/52 (50%) had improved hypertension. 2/52 patients (3.8%) showed no improvement in blood pressure post-operatively. Median (range) serum potassium level increased from 3.2 (2.3-4.7) mmol/l pre-operatively to 4.4 mmol/l (3.3-5.3) post-operatively, P < 0.0001). Median (range) number of antihypertensive medications used fell from 3 (0-6) pre- to 1 post-operatively (range 0-4), P < 0.0001.

CONCLUSIONS

Unilateral adrenalectomy provides excellent long-term improvements in blood pressure control, polypharmacy and hypokalaemia in patients with lateralizing PA. These data may help inform discussions with patients contemplating surgery.

Determinants of survival and attempted resection in patients with non-metastatic pancreatic cancer: An Australian population-based study

BACKGROUND

There are indications that pancreatic cancer survival may differ according to sociodemographic factors, such as residential location. This may be due to differential access to curative resection. Understanding factors associated with the decision to offer a resection might enable strategies to increase the proportion of patients undergoing potentially curative surgery.

METHODS

Data were extracted from medical records and cancer registries for patients diagnosed with pancreatic cancer between July 2009 and June 2011, living in one of two Australian states. Among patients clinically staged with non-metastatic disease we examined factors associated with survival using Cox proportional hazards models. To investigate survival differences we examined determinants of: 1) attempted surgical resection overall; 2) whether patients with locally advanced disease were classified as having resectable disease; and 3) attempted resection among those considered resectable.

RESULTS

Data were collected for 786 eligible patients. Disease was considered locally advanced for 561 (71%) patients, 510 (65%) were classified as having potentially resectable disease and 365 (72%) of these had an attempted resection. Along with age, comorbidities and tumour stage, increasing remoteness of residence was associated with poorer survival. Remoteness of residence and review by a hepatobiliary surgeon were factors influencing the decision to offer surgery.

CONCLUSIONS

This study indicated disparity in survival dependent on patients' residential location and access to a specialist hepatobiliary surgeon. Accurate clinical staging is a critical element in assessing surgical resectability and it is therefore crucial that all patients have access to specialised clinical services.

Sensitive and accurate quantification of JAK2 V617F mutation in chronic myeloproliferative neoplasms by droplet digital PCR

The JAK2 V617F mutation can be detected with a high frequency in patients with myeloproliferative neoplasms (MPN). MPN treatment efficiency can be assessed by JAK2 V617F quantification. Real-time quantitative PCR (qPCR) is widely used for JAK2 V617F quantification. Emerging alternative technologies like digital droplet PCR (ddPCR) have been described to overcome inherent qPCR limitations. The purpose of this study was to evaluate the utility of ddPCR for JAK2 V617F quantification in patient samples with MPN. Sensitivity and specificity were established by using DNA artificial mixtures. In addition, 101 samples from 59 patients were evaluated for JAK2 V617F mutation. Limit of detection was 0.01 % for both qPCR and ddPCR. The JAK2 V617F mutation was detected in 43 out of 59 patients by both PCR platforms. However, in 14 % of the samples, JAK2 V617F mutation was detected only with ddPCR. This 14 % of discrepant samples were from patients shortly after allogeneic stem cell transplantation. Percentage of JAK2 V617F mutation measured by qPCR and ddPCR in clinical samples showed a high degree of correlation (Spearman r: 0.9637 p < 0.001) and an excellent agreement assessed by Bland-Altman analysis. In conclusion, ddPCR is a suitable, precise, and sensitive method for quantification of the JAK 2 V617F mutation.

Vitamin D and pancreatic cancer: a pooled analysis from the Pancreatic Cancer Case-Control Consortium

BACKGROUND

The potential role of vitamin D in the aetiology of pancreatic cancer is unclear, with recent studies suggesting both positive and negative associations.

PATIENTS AND METHODS

We used data from nine case-control studies from the International Pancreatic Cancer Case-Control Consortium (PanC4) to examine associations between pancreatic cancer risk and dietary vitamin D intake. Study-specific odds ratios (ORs) were estimated using multivariable logistic regression, and ORs were then pooled using a random-effects model. From a subset of four studies, we also calculated pooled estimates of association for supplementary and total vitamin D intake.

RESULTS

Risk of pancreatic cancer increased with dietary intake of vitamin D [per 100 international units (IU)/day: OR = 1.13, 95% confidence interval (CI) 1.07-1.19, P = 7.4 × 10(-6), P-heterogeneity = 0.52; ≥230 versus <110 IU/day: OR = 1.31, 95% CI 1.10-1.55, P = 2.4 × 10(-3), P-heterogeneity = 0.81], with the association possibly stronger in people with low retinol/vitamin A intake.

CONCLUSION

Increased risk of pancreatic cancer was observed with higher levels of dietary vitamin D intake. Additional studies are required to determine whether or not our finding has a causal basis.

An internal validation approach and quality control on hematopoietic chimerism testing after allogeneic hematopoietic cell transplantation

BACKGROUND

Hematopoietic chimerism analysis is important in the follow-up of patients undergoing allogeneic stem cell transplantation. PCR of short tandem repeats is mainly used for monitoring chimerism after transplantation. Validation studies and precision of assay's performance with respect to different mixed chimerism stages is not fully addressed. The aim of the present study was to assess the impact of several microsatellite analytical parameters in the quantification of hematopoietic chimerism after allogeneic hematopoietic stem cell transplantation and to analyze the overall analytical process through the application of internal quality control procedures.

METHODS

Artificial DNA mixtures prepared in known proportions and patients samples were analyzed using three microsatellites, together with amplification of amelogenin gene and fluorescence in situ hybridization (FISH) for X and Y chromosomes. Limit of detection, analytical and clinical sensitivity, stochastic threshold and precision profiling was established. Levey-Jennings charts and Westgard rules were applied for quality control evaluation.

RESULTS

Analytical and clinical sensitivity of the microsatellite markers was between 0.5% and 1.6%. Amelogenin detection and FISH for X and Y chromosomes showed a similar sensitivity. Severe allelic imbalance resulted in up to 50% difference between the calculated and corrected mixed chimerism. Systematic errors were identified using Levey-Jennings charts and Westgard rules.

CONCLUSIONS

Analysis of hematopoietic chimerism performance is a critical step to better understand potential intrinsic errors that may impact the final hematopoietic chimerism results. Implementing quality control tools, such as Levey-Jennings charts together with Westgard rules can identify systematic and random errors so corrective actions can be performed.

Soluble HLA-G molecules and HLA-G 14-base pair polymorphism after allogeneic hematopoietic cell transplantation

HLA-G 14-base pair (bp) polymorphism and soluble human leukocyte antigen G were previously reported to be implicated in allogeneic hematopoietic cell transplantation (allo-HSCT) outcome. However, soluble HLA-G blood levels and the 14-bp insertion-deletion polymorphism were separately assessed in the context of allo-HSCT. The aim of the present study was to examine the influence of the 14-bp insertion/deletion polymorphism of the HLA-G gene together with the soluble HLA-G plasma levels on allo-HSCT complications. We investigated the possible impact of HLA-G 14-bp polymorphism together with the pretransplantation and posttransplantation concentration of soluble HLA-G in 59 patients undergoing allo-HSCT. No association was found between the HLA-G 14-bp polymorphism, the soluble HLA-G level and acute graft-versus-host disease (GvHD), disease recurrence, or death. In contrast with previous reports the present data suggest a weak or negligible involvement of both 14-bp polymorphism on HLA-G gene and sHLA-G concentration in posttransplantation complications such as acute or chronic GvHD, relapse, or death.

Diagnostic utility of a soluble cytokeratin 18 assay for gastrointestinal graft-vs.-host disease detection

BACKGROUND

Gastrointestinal/liver graft-vs.-host disease is a frequent complication after allogeneic hematopoietic cell transplantation. Endoscopic biopsies are needed to confirm clinical diagnosis, but this is not always feasible due to concurrent complications after transplantation. Cytokeratin 18 is expressed in epithelial colon cells and hepatocytes. Apoptosis, a hallmark of graft-vs.-host disease, results in the cleavage of cytokeratin 18 and the resulting fragments are released into the circulation.

METHODS

The aim of the present study was to assess the general performance and usefulness of a serologic test for soluble cytokeratin 18 for gastrointestinal/liver graft-vs.-host disease detection. Plasmatic concentration of soluble cytokeratin 18 was measured in 38 individuals undergoing hematopoietic cell transplantation. A two-fold increase of sCK18 above the pre-transplant concentration was used as a threshold value.

RESULTS

Plasmatic concentration of soluble cytokeratin 18 was significantly elevated in patients with gastrointestinal/liver graft-vs.-host disease. Soluble cytokeratin 18 concentration raised before the onset of clinical symptoms in 69% of the patients with gastrointestinal/liver graft-vs.-host disease. The threshold value used in our study resulted in a high sensitivity and a low false negative rate for gastrointestinal/liver graft-vs.-host disease detection.

CONCLUSIONS

Soluble cytokeratin 18 seems to be a suitable biomarker for gastrointestinal/liver graft-vs.-host disease detection, particularly when a biopsy is not feasible.

Horizontal DNA transfer from donor to host cells as an alternative mechanism of epithelial chimerism after allogeneic hematopoietic cell transplantation

Animal and human studies have shown that after allogeneic hematopoietic cell transplantation, epithelial cells containing donor-derived genome emerge. The mechanisms underlying this phenomenon are still unclear. We hypothesized that horizontal transfer of the hematopoietic donor-DNA to the host epithelium confers a possible operating mechanism. In an in vitro model mimicking the lymphocyte-epithelial interaction, we cocultivated keratinocyte HaCaT cells (Y-chromosome negative) with nonapoptotic or apoptotic, CMFDA, or BrdU-labeled hematopoietic Jurkat cells (Y+) and looked for the emergence of HaCaT cells bearing Jurkat genome. We found that DNA can be horizontally transferred from hematopoietic to epithelial cell lines through phagocytosis of apoptotic bodies. The ingested genomic material was also found within the nuclear compartment and in isolated chromosomes obtained from HaCaT metaphases. Both lysosomal inhibition in HaCaT cells and repetitive load of HaCaT cells with apoptotic bodies increased the intercellular and intranuclear DNA delivery. Although recipient cells remained viable and showed to express the foreign DNA, this expression was transient. Taking into consideration these findings of horizontal DNA transfer between hematopoietic and epithelial cells, we evaluated by quantitative microsatellite analysis the amount of donor DNA in 176 buccal swabs obtained from 71 patients after allogeneic transplantation. We found a high amount of donor-DNA (mean 26.6%) in the majority (89.7%) of them, although no donor hematopoietic cells were evident in the samples by immunofluorescence. We propose that the incessant charge of the transplant recipient with donor-DNA and its "inappropriate" intranuclear delivery in host epithelium may explain the emergence of epithelial cells with donor-derived genome.

Sequential analysis of uncommon adverse outcomes

Sequential analysis of uncommon adverse outcomes (AEs) such as surgical site infections (SSIs) is desirable. Short postoperative lengths of stay (LOS) result in many SSIs occurring after discharge and they are often superficial. Deep and organ space (complex) SSIs occur less frequently but are detected more reliably and are suitable for monitoring wound care. Those occurring post-discharge usually require readmissison and can be counted accurately. Sequential analysis of meticillin-resistant Staphylococcus aureus bacteraemia is also needed. The key to prevention is to implement systems based on evidence, e.g. using 'bundles' and checklists. Regular mortality and morbidity audit meetings are required and these may need to be followed by independent audits. Sequential statistical analysis is desirable for data presentation, to detect changes, and to discourage tampering with processes when occasional AEs occur in a reliable system. Tabulations and cumulative observed minus expected (O-E) charts and funnel plots are valuable, supplemented in the presence of apparent 'runs' of AEs by cumulative sum analysis. Used prospectively, they may enable staff to visualise and detect patterns or shifts in rates and counts that might not otherwise be apparent.

Frequent genomic alterations in epithelium measured by microsatellite instability following allogeneic hematopoietic cell transplantation in humans

Although typically found in cancers, frameshift mutations in microsatellites have also been detected in chronically inflamed tissues. Allogeneic hematopoietic cell transplantation (HCT) may potentially produce chronic tissue stress through graft-versus-host reactions. We examined non-neoplastic epithelial tissues (colon, buccal) obtained 1 to 5061 days after human allogeneic HCT for the presence of genomic alterations at 3 tetranucleotide and 3 mononucleotide microsatellite loci. Novel bands indicative of microsatellite instability (MSI) at tetranucleotide repeats were detected in laser-microdissected colonic crypts and in buccal smears of 75% and 42% of patients who received an allograft, respectively. In contrast, no MSI was found in similar tissues from control subjects and from patients after intensive chemotherapy or in buccal cells from patients after autologous HCT. The MSI found in colon, which was often affected by graft-versus-host disease, was not due to loss of expression or nitrosylation of DNA repair proteins. MSI in clinically intact oral mucosa was more frequently found at later time points after HCT. MSI was also found in 3 posttransplant squamous cell cancers examined. Our data show that genomic alterations in epithelium regularly occur after allogeneic HCT and may be implicated in the evolution of posttransplantation diseases, including secondary cancer.

Reduced Intensity Conditioning Compared to Standard Conditioning Preserves the In Vitro Growth Capacity of Bone Marrow Stroma, Which Remains of Host Origin

The ability of bone marrow (BM) samples to generate confluent stromal layers in long-term BM cultures (LTBMC) was used as a surrogate assay to determine the in vivo toxic effects of different conditionings on stromal cells. Here, 32 patients receiving a fludarabine-based reduced intensity conditioning regimen (FBM) were compared to those in a control group of 23 patients treated with standard busulfan/cyclophosphamide (BuCy; 14 patients) or TBI-based (TBI 12 Gy/VP16/cyclophosphamide; 9 patients) conditioning. BM was aspirated before conditioning, and at day +30 and/or at day +100, obtaining positive stromal cell growth in vitro in 58%, 47%, and 65%, respectively. FBM conditioning did not alter the ability of BM to generate stromal layers both early (day +30, 75%+) or late (day +100, 80%+) after hematopoietic cell transplantation (HCT) as compared to pre-HCT (66.6%+). FBM-treated patients formed confluent stroma significantly more often than standard-treated patients (85% vs. 38% patients; p < 0.05). In an univariate analysis, standard conditioning remained the only factor predicting stromal growth impairment after allogeneic HCT. The ex vivo-generated stromal layers from 5 female, FBM treated, sex-mismatched, and peripheral blood stem cell (PBSC) transplanted patients were analyzed by combined FISH-Y and immunofluorescence stains (Vimentin, CD14, CD45) and found to be exclusively of recipient origin. We conclude that FBM reduced intensity conditioning results in reduced, if any, stromal damage as compared to standard myeloablative treatment. The novel, donor-derived, hematopoiesis in FBM patients after allogeneic transplantation is supported and maintained by a host-derived BM stromal microenvironment.