Haploidentical vs matched unrelated donor transplantation for acute myeloid leukemia in remission: A prospective comparative study.

Despite comparable outcomes of haploidentical transplants (Haplo-HSCT) with HLA-matched unrelated transplants (MUD-HSCT) in retrospective comparisons, few studies have prospectively compared Haplo-HSCT with MUD-HSCT in AML. Here, we prospectively compared the outcomes of Haplo-HSCT with MUD-HSCT for AML in remission (n = 110) to prove non-inferiority of overall survival in Haplo-HSCT. Both groups were well balanced in factors related to biological features of AML and measurable residual disease (MRD) status by Wilms' tumor gene 1 (WT1) assay. A unique, reduced-toxicity preparative regimen was used for Haplo-HSCT, whereas mostly-myeloablative regimen was for MUD-HSCT. Both groups showed similar patterns of neutrophil and platelet recovery, whereas delayed T-cell reconstitution in Haplo-HSCT was found compared with MUD-HSCT. No significant differences were found in acute or chronic graft-vs-host-disease (GVHD) and post-transplant infectious events with an exception of EBV or CMV infection, which occurred more frequently in Haplo-HSCT. After a median follow-up of 47 months, no significant differences in overall survival (65% vs 54%, P = .146), disease-free survival (67% vs 53%, P = .142), relapse (20% vs 21%, P = .858), non-relapse mortality (14% vs 26%, P = .103), or GVHD-free/relapse-free survival (54% vs 41%, P = .138) were observed for Haplo-HSCT vs MUD-HSCT. In multivariate analysis, WT1 expression before transplantation independently predicted relapse, resulting in inferior survival. Separate analysis of unenrolled patients (n = 110) who were excluded or refused to participate in this study showed consistent results with enrolled patients. This prospective study demonstrated the non-inferiority of Haplo-HSCT to MUD-HSCT for AML in remission, and validated the role of WT1 quantification as an MRD marker (ClinicalTrial.gov identifier: NCT01751997).

WT1 Gene Expression in Peripheral Blood Before and After Allogeneic Stem Cell Transplantation is a Clinically Relevant Prognostic Marker in AML - A Single-center 14-year Experience.

BACKGROUND: This work summarizes our experience with WT1 monitoring before and after allogeneic hematopoietic stem cell transplantation (allo-HSCT). PATIENTS AND METHODS: The expression of WT1 gene was measured by real-time polymerase chain reaction in peripheral blood according to the European Leukemia Net recommendations. Between May 2005 and August 2019, we analyzed 147 consecutive patients with acute myeloid leukemia with high WT1 expression at diagnosis, transplanted in first (CR1) or second (CR2) complete remission. RESULTS: At the time of allo-HSCT, 107 patients had WT1-normal expression (WT1 ≤ 50 copies), and 40 patients had WT1-high expression. The median follow-up was 21 months. The estimated 5-year overall survival and event-free survival was significantly better in the WT1-normal cohort (65% and 57% vs. 37% and 25%; P = .0003 and P < .0001, respectively) and 5-year cumulative incidence of relapse was significantly lower in the WT1-normal group (19% vs. 53%; P < .0001). Five-year non-relapse mortality was not significantly different (20% and 23%). Multivariate analysis revealed WT1-high expression and acute graft-versus-host disease grade 3/4 as significantly negative prognostic factors for OS. Overall, 49 patients developed WT1 molecular relapse in the post-transplant period; in 14 cases, the therapeutic intervention was done. In all but 1 relapsed patient where WT1 minimal residual disease (MRD) was monitored (38 patients), we detected WT1-high levels (sensitivity of 97%). CONCLUSION: The results of the analysis confirmed our previous experience that WT1 status before allo-HSCT is a strong prognostic factor for both OS and relapse risk. In addition, we confirmed the usefulness of this marker for MRD monitoring after allo-HSCT. The main advantage is the possibility of frequent MRD monitoring in peripheral blood and early bone marrow examination based on WT1-high expression.

One-Step Duplex Droplet Digital PCR for WT1 Overexpression.

With the improvement of treatment methods in acute hematology malignancies, the development of sensitive tools for minimal residual disease assessment has become a priority. The monitoring of WT1 expression level by real-time quantitative PCR has been a standard for minimal residual disease evaluation in acute myeloid leukemia and, since 2009, has been optimized through a European LeukemiaNet effort in an established protocol with well-defined clinical end points. Building on the work of the European LeukemiaNet, this article reports the development of a novel, one-step duplex WT1/ABL1 droplet digital assay for WT1 overexpression detection. This assay provides accurate data with high precision and linearity, even at low-template concentration, while retaining strong correlation with the standardized method and therefore maintaining the framework to analyze the results in the context of acute myeloid leukemia patients.

Analysis of pre-chemotherapy WBC, PLT, monocyte, hemoglobin, and MPV levels in acute myeloid leukemia patients with WT1, FLT3, or NPM gene mutations.

Effects of mutations on AML (acute myeloid leukemia) patients have been an area of clinical interest. The aim of this study was to analyze pre-chemotherapy WBC (white blood cell), platelet, monocyte, hemoglobin, and mean platelet volume (MPV) levels in acute myeloid leukemia patients with Wilms tumor 1 (WT1), FMS-like tyrosine kinase 3 (FLT3), or nucleophosmin (NPM) gene mutations, attempting to detect and compare possible differences in these values.The study included 71 patients with acute myeloid leukemia known to have WT1, FLT3, or NPM gene mutations. The patients were divided into 3 groups: FLT3-mutated AML patients without any accompanying known mutations other than WT1 at the time of diagnosis (Group 1), NPM-mutated AML patients without any accompanying known mutations other than WT1 at the time of diagnosis (Group 2), WT1-mutated AML patients with no other accompanying known mutations at the time of diagnosis (Group 3). We carried out intergroup comparisons of WBC, platelet (PLT), monocyte, hemoglobin, and MPV levels before chemotherapy.There was a statistically significant difference between the groups in terms of WBC parameters (P = .001). There were no statistically significant differences between the groups with respect to hemoglobin, platelet, and monocyte levels.Higher white blood cell counts could be observed in patients with FLT3-mutated AML.

The influence of Wilms' tumor 1 gene expression level on prognosis and risk stratification of acute promyelocytic leukemia patients.

INTRODUCTION: Patients with acute promyelocytic leukemia (APL) are characterized by the highest expression of Wilms' tumor 1 (WT1) gene compared with other subtypes of acute myeloid leukemia, and yet this molecular marker is almost never used for risk stratification and in therapy response monitoring. METHODS: Quantitative assessment of Wilms' tumor 1 (WT1) gene transcripts was performed using real-time PCR method. The bone marrow samples were collected at the time of diagnosis for 47 APL patients, and for 31/47 patients during follow-up/relapse of the disease (129 samples in total). We examined how this molecular marker can be used for prognosis and minimal residual disease (MRD) monitoring. RESULTS: Increased WT1 expression was found in 34% of patients. WT1high status was an independent unfavorable factor for early death occurrence and was associated with shorter overall survival (OS). Assessment of log reduction value of WT1 expression in paired diagnosis/complete remission samples did not reveal its impact on relapse rate, disease-free survival, and OS. Also, measurement of WT1 expression level at different time points during therapy was not a reliable method for MRD monitoring. CONCLUSION: Increased expression of WT1 gene detected in high proportion of APL patients could be considered as a marker for more precise risk stratification models in an attempt to further improve treatment and outcome of APL patients.

Prognostic impact of peripheral blood WT1-mRNA expression in patients with MDS.

Few reports suggested a prognostic impact of Wilms'Tumor-1 (WT1)-mRNA overexpression in MDS, but translation into clinical routine was hampered by limited patients numbers, differing sample sources, non-standardized methods/cut-offs. To evaluate whether WT1-mRNA expression yields additional prognostic information, we measured peripheral blood (PB) WT1-mRNA expression in 94 MDS using a standardized assay offering a validated cut-off to discriminate between normal and WT1-mRNA overexpression. Overall, 54 patients (57%) showed WT1-mRNA overexpression, while 40 patients (43%) had normal WT1-mRNA expression. This enabled discrimination between MDS and both healthy controls and non-MDS cytopenias. Furthermore, WT1-mRNA expression correlated with WHO 2016 subcategories and IPSS-R as indicated by mean WT1-mRNA expression and frequency of WT1-mRNA overexpressing patients within respective subgroups. Regarding the entire group, PB WT1-mRNA expression was associated with prognosis, as those patients showing WT1-mRNA overexpression had higher risk for disease progression and AML transformation and accordingly shorter progression-free, leukemia-free and overall survival in univariate analysis. In multivariate analysis, prognostic impact of PB WT1-mRNA expression status was independent of IPSS-R and enabled more precise prediction of PFS, but not OS, within IPSS-R very low/low and intermediate risk groups. Overall, measuring PB WT1-mRNA appears valuable to support diagnostics and refine prognostication provided by the IPSS-R.

Treatment of Molecular Relapse by Cessation of Immunosuppression After Hematopoietic Stem Cell Transplantation in Pediatric FLT3-ITD AML Monitored by WT1 Expression in Peripheral Blood.

Relapse after hematopoietic stem cell transplantation in pediatric acute myeloid leukemia is a fatal event in the majority of cases. Immunotherapy may prevent an impending relapse if instituted at first molecular evidence of disease recurrence. Wilms tumor gene 1 (WT1) is overexpressed in the majority of children and may constitute a useful molecular marker of measurable residual disease applicable for disease monitoring in peripheral blood where the background amplification from healthy hematopoiesis is less prevalent compared with bone marrow. We report the measurable residual disease kinetics from a child with FLT3-internal tandem duplication acute myeloid leukemia where sequential WT1 monitoring in peripheral blood-guided withdrawal of immunosuppression.

Measurable residual disease monitoring using Wilms tumor gene 1 expression in childhood acute myeloid leukemia based on child-specific reference values.

BACKGROUND: Measurable/minimal residual disease (MRD) monitoring can predict imminent hematological relapse in acute myeloid leukemia (AML). The majority of childhood AML patients do not harbor fusion genes or mutations applicable as MRD markers and overexpression of Wilms tumor gene 1 (WT1) may constitute a useful monitoring target. However, age-specific reference values in healthy hematopoiesis and standardization of WT1 assessment are prerequisites for clinical utility. PROCEDURE: We investigated WT1 expression across age in hematologically healthy controls (n = 109), during suspected infection (n = 90) and bone marrow (BM) regeneration (n = 13). WT1 expression in AML at diagnosis (n = 91) and during follow-up (n = 30) was compared with age-specific reference values. RESULTS: WT1 expression correlated with age and showed higher levels in both BM and peripheral blood (PB) in children compared with adults (P < 0.001 and P = 0.01). WT1 expression from healthy hematopoiesis was lower in PB compared with BM (WT1BM /WT1PB  = 8.6, 95% CI: 5.3-13.7) and not influenced by infection nor BM regeneration. At AML diagnosis, 66% had more than 20-fold WT1 overexpression in PB or BM (PB 74%; BM 45%). WT1 was quantified in 279 PB samples during follow-up. All 11 patients with PB sampling within 4 months of disease recurrence displayed WT1 overexpression by a median of 1.9 months (range, 0.7-9.7) before hematological relapse. CONCLUSIONS: This study defines child-specific reference values for WT1 expression in healthy hematopoiesis and demonstrates that WT1 expression in PB is a useful post-treatment monitoring tool in childhood AML. Based on these observations, we propose definitions for childhood AML molecular relapse using WT1 overexpression.

The Proportional Relationship Between Pretransplant WT1 mRNA Levels and Risk of Mortality After Allogeneic Hematopoietic Cell Transplantation in Acute Myeloid Leukemia Not in Remission.

BACKGROUND: The relationship between the expression levels of Wilms' tumor-1 gene (WT1) mRNA in peripheral blood before allogeneic hematopoietic cell transplantation (allo-HCT) and risk of mortality in acute myeloid leukemia (AML) patients in noncomplete remission (non-CR) remains quite elusive. METHODS: We retrospectively assessed the impact of the pretransplant WT1 mRNA level on survival after allo-HCT in non-CR AML patients. RESULTS: A total of 125 AML patients, including 46 non-CR patients (36.8%), were analyzed. On multivariate analysis of non-CR AML patients, WT1 mRNA ≥5000 copies/µg RNA was significantly related to increased risk of mortality (hazard ratio, 2.7; 95% confidence interval, 1.3-5.5; P = 0.008). Furthermore, in the entire cohort, log10-transformed WT1 mRNA before allo-HCT was found to be significantly associated with the increased risk of mortality irrespective of whether the disease status was CR or non-CR, using Akaike's information criterion. As the pretransplant WT1 mRNA level elevated, the hazard ratio of mortality monotonically increased in a nonlinear manner regardless of remission status, suggesting that WT1 mRNA level in peripheral blood might reflect tumor burden. CONCLUSIONS: This study demonstrated that the pretransplant WT1 mRNA level was a powerful prognostic factor in allo-HCT even for non-CR AML patients, and there may be a WT1 mRNA threshold in non-CR patients for benefiting from allo-HCT.

Associations between the peripheral blood Wilms tumor gene 1 level and both bone marrow blast cells and the prognosis in patients with myelodysplastic syndrome.

Wilms tumor gene 1 (WT1) is highly expressed in myelodysplastic syndrome (MDS) cells and is known to reflect the tumor burden in MDS. We evaluated the usefulness of WT1 mRNA levels for predicting the prognosis of MDS. At diagnosis, WT1 levels were strongly correlated with the percentage of blasts calculated based on non-erythroid cells, but not with that based on all nucleated cells (r = 0.57, p < .05 vs r = 0.42, p = .13). Among the allogeneic transplant recipients, the presence of two consecutive WT1 levels ≥100 copies/µg RNA with a median interval of one month was associated with a 77.8% relapse rate at nine months from the first detection of a high WT1 level, and the median time to relapse was only 114 [36-257] days. WT1 levels at diagnosis were correlated with known prognostic factors. In addition, the presence of two consecutive high WT1 levels after allogeneic transplantation may predict early relapse of MDS.

Outcomes of Measurable Residual Disease in Pediatric Acute Myeloid Leukemia before and after Hematopoietic Stem Cell Transplant: Validation of Difference from Normal Flow Cytometry with Chimerism Studies and Wilms Tumor 1 Gene Expression.

We enrolled 150 patients in a prospective multicenter study of children with acute myeloid leukemia undergoing hematopoietic stem cell transplantation (HSCT) to compare the detection of measurable residual disease (MRD) by a "difference from normal" flow cytometry (ΔN) approach with assessment of Wilms tumor 1 (WT1) gene expression without access to the diagnostic specimen. Prospective analysis of the specimens using this approach showed that 23% of patients screened for HSCT had detectable residual disease by ΔN (.04% to 53%). Of those patients who proceeded to transplant as being in morphologic remission, 10 had detectable disease (.04% to 14%) by ΔN. The disease-free survival of this group was 10% (0 to 35%) compared with 55% (46% to 64%, P < .001) for those without disease. The ΔN assay was validated using the post-HSCT specimen by sorting abnormal or suspicious cells to confirm recipient or donor origin by chimerism studies. All 15 patients who had confirmation of tumor detection relapsed, whereas the 2 patients with suspicious phenotype cells lacking this confirmation did not. The phenotype of the relapse specimen was then used retrospectively to assess the pre-HSCT specimen, allowing identification of additional samples with low levels of MRD involvement that were previously undetected. Quantitative assessment of WT1 gene expression was not predictive of relapse or other outcomes in either pre- or post-transplant specimens. MRD detected by ΔN was highly specific, but did not identify most relapsing patients. The application of the assay was limited by poor quality among one-third of the specimens and lack of a diagnostic phenotype for comparison.

Clinical Utility of Wilms' Tumor 1 Monitoring in Patients with Myeloid Malignancy and Prior Allogeneic Hematopoietic Stem Cell Transplantation.

Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) is 1 of the standard treatments for myeloid malignancy, relapse remains a major obstacle to cure. Early detection of relapse by monitoring of minimal residual disease (MRD) may enable us to intervene pre-emptively and potentially prevent overt relapse. Wilms' tumor 1 (WT1) is well known as a pan-leukemic marker. We retrospectively examined serially monitored WT1 levels of peripheral blood in 98 patients (84 with acute myeloid leukemia and 14 with myelodysplastic syndrome). At the time of allo-HSCT, 49 patients (50%) were in complete remission. Patients were divided into 3 groups according to WT1 levels (<50 copies/µg RNA, 50 to 500 copies/µg RNA and >500 copies/µg RNA). The cumulative incidence of relapse (CIR) and overall survival (OS) differed statistically according to the WT1 levels before allo-HSCT and at days 30 and 60 after allo-HSCT. In multivariate analysis, WT1 >500 copies/µg RNA before and at day 60 after allo-HSCT and WT1 ≥50 copies/µg RNA at day 30 were correlated with CIR. Moreover, WT1 >500 copies/µg RNA at day 60 after allo-HSCT was only correlated with worse OS. Our data suggest that serial monitoring of WT1 levels in peripheral blood may be useful for MRD monitoring and as a predictor of hematological relapse in allo-HSCT.

Impact of Wilms' tumor 1 expression on outcome of patients undergoing allogeneic stem cell transplantation for AML.

The monitoring of the minimal residual disease by Wilms' tumor 1 expression (MRDWT1) is a standardized test, which can be used in over 80% of patients with AML. To investigate the prognostic value of MRDWT1 in patients undergoing allogeneic stem cell transplantation (allo-SCT) for AML, MRDWT1 was monitored 3 months after transplantation in 139 patients. MRDWT1 positivity did not lead to any therapeutic intervention. Median follow-up was 39.3 (6.4-99.8) months. Patients with positive MRDWT1 at 3 months experienced more often post-transplant relapse (27/30, 90%) than those with negative MRDWT1 (16/109, 14.7%) (P<0.0001). Similarly, a shorter 3-year event-free survival (EFS) was observed in MRDWT1-positive patients (10% vs 72.3% in MRDWT1-negative patients, P<0.0001). The correlation between relapse and MRDWT1 was stronger in blood than in bone marrow samples. Multivariate analysis confirmed the detrimental role of 3-month positive MRDWT1 for relapse (hazard ratio (HR): 15.42; 95% confidence interval (CI): 7.53-31.59; P<0.0001) and EFS (HR: 10.71; 95% CI: 5.41-21.21; P<0.0001). Interestingly, 3-month chimerism was less predictive of relapse than positive MRDWT1. In conclusion, our results demonstrate the usefulness of peripheral blood MRDWT1 monitoring in identifying very high-risk patients, who could benefit from an early preemptive treatment, and those who do not need such an intervention.

Assessment of WT1 Expression as a Marker of Treatment Outcome in Karyotype Normal Acute Myeloid Leukemia Patients in Pakistan.

Currently, there is an effort to predict relapse by follow-up monitoring of MRD and subsequently to begin the treatment of the patients during their clinical and hematological remission prior to overt hematological relapse. Expression of WT1 in AML is known to be independently associated with significant inferior response to therapy and short survival outcome. Follow-up monitoring of WT1 gene expression during or after therapy would be a valuable predictive marker for early recurrence or relapse of AML disease. This pilot study evaluated newly diagnosed and post-induction or consolidation chemotherapy of AML patients who were registered with the Oncology Clinics of the Aga Khan University Hospital, Karachi. High WT1 burden (> 5000 copies/ml) in 2 patients was indicative of early recurrence of the disease along with shorter disease-free and overall survival. Low WT1 expression (< 200 copies/ml) in 2 patients after induction and consolidation therapy, respectively, was suggestive of better prognosis.

A 4-gene expression score associated with high levels of Wilms Tumor-1 (WT1) expression is an adverse prognostic factor in acute myeloid leukaemia.

Wilms Tumor-1 (WT1) expression level is implicated in the prognosis of acute myeloid leukaemia (AML). We hypothesized that a gene expression profile associated with WT1 expression levels might be a good surrogate marker. We identified high WT1 gene sets by comparing the gene expression profiles in the highest and lowest quartiles of WT1 expression in two large AML studies. Two high WT1 gene sets were found to be highly correlated in terms of the altered genes and expression profiles. We identified a 17-probe set signature of the high WT1 set as the optimal prognostic predictor in the first AML set, and showed that it was able to predict prognosis in the second AML series after adjustment for European LeukaemiaNet genetic groups. The gene signature also proved to be of prognostic value in a third AML series of 163 samples assessed by RNA sequencing, demonstrating its cross-platform consistency. This led us to derive a 4-gene expression score, which faithfully predicted adverse outcome. In conclusion, a short gene signature associated with high WT1 expression levels and the resultant 4-gene expression score were found to be predictive of adverse prognosis in AML. This study provides new clues to the molecular pathways underlying high WT1 states in leukaemia.

Increase in myeloid-derived suppressor cells (MDSCs) associated with minimal residual disease (MRD) detection in adult acute myeloid leukemia.

Myeloid-derived suppressor cells (MDSCs) are thought to help provide a cellular microenvironments in many solid tumors, in which transformed cells proliferate, acquire new mutations, and evade host immunosurveillance. In the present study, we found that MDSCs (CD33 + CD11b + HLA-DR(low/neg)) in bone marrow were significantly increased in adult acute myeloid leukemia (AML) patients. MDSCs levels in newly diagnosed AML patients correlated well with extramedullary infiltration and plasma D-dimer levels. Remission rates in the MDSCs > 1500 group and MDSCs < 1500 group were 72.73 and 81.25 %, respectively. No significant differences were found between the two groups. MDSC levels in the complete remission group were significantly decreased after chemotherapy, while in the partial remission and non-remission groups, there were no significant differences. The level of MDSCs in the high minimal residual disease (MRD) group was significantly higher than that in the middle and low MRD groups. High levels of Wilms' Tumor-1 (WT-1) protein were strongly correlated with higher bone marrow MDSC levels. In conclusion, we report here a population of immunosuppressive monocytes in the bone marrow of patients with AML characterized by the CD33(high)CD11b + HLA-DR(low/neg) phenotype. These cells appear to impact the clinical course and prognosis of AML. This data may provide potentially important targets for novel therapies.

Expression of WT-1 by the vascular component of acral pseudolymphomatous angiokeratoma of children.

Acral pseudolymphomatous angiokeratoma of children (APACHE) is a disease comprised by a dense dermal infiltrate of B-lymphocytes and T-lymphocytes in which prominent blood vessels with plump endothelium are found. In the past, the lesion was interpreted as a variant of angiokeratoma, a vascular malformation, or a nevus. Currently, most authors consider it to be a type of pseudolymphoma with prominent blood vessels. The latter express CD34 and D2-40, while they lack the expression of Glut-1. The expression of Wilms tumor-1 (WT-1) by APACHE has not yet been studied. In this report, we present a case of APACHE on the right foot of a 4-year-old boy and demonstrate immunoexpression of WT-1 by the blood vessels of the lesion. We also performed serial sections and demonstrated that the WT-1+ vessels with prominent endothelium were D2-40-.

Real-time assessment of relapse risk based on the WT1 marker in acute leukemia and myelodysplastic syndrome patients after hematopoietic cell transplantation.

Relapse is the major cause of treatment failure after allogeneic hematopoietic cell transplantation (alloHCT) for acute leukemia and myelodysplastic syndrome (MDS). Wilms' tumor Ag (WT1) is overexpressed in the majority of acute leukemia and MDS patients and has been proposed as a universal diagnostic marker for detection of impending relapse. Comprehensive studies have shown that WT1 transcript levels have predictive value in acute leukemia patients in CR after chemotherapy. However, the focus of this study is the period after alloHCT for predicting relapse onset. We analyzed the accumulation of WT1 mRNA transcripts in PB of 82 leukemia and MDS patients and defined specific molecular ratios for relapse prediction. The extensively validated WT1/c-ABL ratio was used to normalize increases in WT1 transcript levels. The observed lead time of crossing or exceeding set WT1 levels is presented along with linear interpolation to estimate the calculated day the WT1 thresholds were crossed. The WT1/c-ABL transcript ratio of 50 or above yielded 100% specificity and 75% sensitivity reliably predicting future relapse with an observed average of 29.4 days (s.d.=19.8) and a calculated average of 63 days (s.d.=29.3) lead time before morphologic confirmation. A lower ratio of 20 or above gave lower specificity, but higher sensitivity (84.8% and 87.5%, respectively) identified more patients who relapsed, at earlier times, providing an earlier warning with actual average lead time of 49.1 days (s.d.=30.8) and calculated average of 78 days (s.d.=28.8). WT1 transcript levels serve as a diagnostic relapse test with greater sensitivity than the morphologic approach used in the clinic as a readout.

Ustekinumab improves psoriasis without suppressing tumor antigen-specific cytotoxic T lymphocytes.

BACKGROUND: Ustekinumab is currently used for the treatment of psoriasis with remarkable efficiency. However, worries about the development of malignancies in ustekinumab-treated patients have not been completely resolved because of the major role of IL-12 and IL-23 in tumor immunity. In the present study, we tried to elucidate the effects of ustekinumab on antigen-specific tumor immunity. METHODS: After approval by the institutional ethical committee, a 56-year-old male volunteer with psoriasis was administered with 20 doses of WT1 peptide. WT1-specific cytotoxic T lymphocytes (CTLs) were evaluated by WT1 tetramer assay after mixed lymphocyte peptide culture. RESULTS: WT1 tetramer+ T cells with cytotoxic ability appeared in the blood after peptide administration and the frequency of WT1 tetramer+ T cells increased to more than 15 in 10(6) CD8+ T cells. Thirty months after stopping WT1 administration, the patient commenced treatment with ustekinumab for psoriasis at weeks 0 and 4, and every 12 weeks thereafter. Psoriasis plaques were almost cleared up and the response to ustekinumab has so far lasted for 30 months. The frequency of WT1 tetramer+ T cells has not changed since the initiation of ustekinumab treatment. The effects of ustekinumab on the antigen-presenting and CTL-inducing abilities of dendritic cells were explored in vitro, revealing limited effects on both immune functions. CONCLUSIONS: These in vivo/vitro findings imply that ustekinumab improves psoriasis without suppressing tumor antigen-specific CTLs and support the data of recent clinical trials showing no increased incidence of malignancies with ustekinumab treatment.

Peripheral blood WT1 expression predicts relapse in AML patients undergoing allogeneic stem cell transplantation.

To evaluate if WT1 expression may predict relapse after allo-SCT, we analyzed WT1 levels on peripheral blood (PB) and bone marrow (BM) before and after allo-SCT in 24 AML patients with WT1 overexpression at diagnosis. Five copies of WT1/ABL × 10(4) from PB were identified as the threshold value that correlated with relapse after allo-SCT. The same correlation was not identified when WT1 expression was assessed from bone marrow (BM). Eight out of 11 (73%) patients with a pre-allo-SCT PB-WT1 ≥ 5 and 4/13 (31%) patients with a pre-allo-SCT PB-WT1 < 5 relapsed, respectively (P = 0.04). The incidence of relapse was higher in patients with PB-WT1 ≥ 5 measured after allo-SCT, at the 3rd (56% versus 38%; P = 0.43) and at the 6th month (71% versus 20%; P = 0.03). Patients with pretransplant PB-WT1 < 5 had significantly better 2-year OS and LFS than patients with a PB-WT1 ≥ 5 (81% versus 0% and 63% versus 20%) (P = 0.02). Our data suggest the usefulness of WT1 monitoring from PB to predict the relapse in allotransplanted AML patients and to modulate the intensity of conditioning and/or the posttransplant immunosuppression in an attempt to reduce the posttransplant relapse risk.