Introduction Clonal hematopoiesis (CH) in solid organ transplant (SOT) recipients can lead to impaired tolerance to immunosuppressive therapy, increased risk for complications, and potentially compromise graft and patient outcomes. The impact of mutational profile in CH on risk for hematological transformation and patient/graft outcomes for kidney transplant (KT) recipients is largely unknown. Our aim was to assess the prevalence of CH and progression of CH in KT, evaluate the impact of CH on allograft function, assess patient outcomes and determine Clonal Hematopoietic Risk Score status. Methods We retrospectively reviewed the CH profile of patients 18+ years of age who received a kidney transplant at Mayo Clinic Enterprise between 01/01/1994-12-31/2022 and underwent bone marrow biopsy with aspirate pre- and/or post-transplant. Bone marrow biopsies were primarily performed post-transplant in the workup for cytopenias. Transplant database was used to collect our variables of interest including post-transplant malignancy and outcomes. CH was ascertained through next-generation sequencing (NGS) on bone marrow samples. A 47-gene panel was utilized in our study. CH was defined by presence of somatic mutation with a variant allele frequency of > 2.0%. CH in absence of cytopenias was classified as CHIP while CH in individuals with one or more cytopenias was classified as clonal cytopenias of undetermined significant (CCUS). The Clonal Hematopoiesis Risk Score (CHRS) was utilized for CHIP and CCUS risk stratification We excluded the patients who had a prior hematologic malignancy. Results 305 kidney transplant recipients met our study criteria. The median time to follow up, defined as time from transplant until first bone marrow biopsy with evidence of CH, was 46.1 months. The frequency of CH in kidney recipients was 27/305 (9.0%), of these 14/27 (52%) patients were found to have CCUS and 10/27 (37%) were found to have evidence of post-transplant myeloid malignancy. Of these cases, 5/10 (50%) developed acute myeloid leukemia while 5/10 (50%) developed myelodysplastic syndrome. Both CCUS and myeloid neoplasms were more common in female patients, accounting for 8/14 (57%) and 7/13 (54%) of each cohort, respectively. Amongst CCUS, the most frequent mutations were seen in ASXL1, DNMT3A and TET2. More than half of patients with CH, 14/27 (52%), exhibited mutations in 2 or more genes. Meanwhile, in cases of myeloid malignancy, the commonly mutated genes were ASXL1 and TP53, seen in 3/10 and 3/10 cases, respectively. The CCUS risk status was intermediate, with median score of 11.8 (range 9.5-14). One CCUS patient transformed to myelodysplastic syndrome. The time to progression from CCUS to myelodysplastic syndrome was 14.3 months and their respective CHRS status was determined to be high-risk. Infectious complications, including viral and opportunistic infections, were seen in 12/27 (44%) recipients with CH, with CMV viremia being the most common, followed by BK viremia. In this cohort, post-transplant cardiovascular events and venous thromboembolic events occurred in 2/27 (7.0%) and 7/27 (26%) patients, respectively. Allograft failure was seen in 17/27 (63%) recipients at a median of 93.4 months post-transplant. After a median of 122 months, there were 14/27 (52%) deaths at a median duration of 93.4 months post-transplant. Causes of mortality included myeloid malignancy, infection, cardiovascular complications, end-stage renal disease or were unknown. Conclusions Renal transplant recipients carry mutations in epigenetic regulators resulting in adverse outcomes. Similar to the general population, DNMT3A, TET2 and ASXL1 mutations were the most common mutations in post-transplant CCUS. Infections, cardiovascular events, and allograft failure were frequent. Prospective studies in a larger cohort are needed to evaluate the impact of CCUS in survival and myeloid malignancy transformation risk.
Clonal Hematopoiesis Landscape in Metastatic Prostate Cancer Patients
Background Clonal hematopoiesis (CH) is defined by somatic mutations in hematopoietic stem cells, often conferring a selection advantage based on clonal selection pressures. CH in DNA Damage Response and Repair (DDR, e.g. TP53, PPM1D) genes are frequent in individuals exposed to chemotherapy and radiation (chemo/XRT). In metastatic prostate cancer (mPC) patients, the prevalence of CH is estimated at 57% and is increased among those with prior exposure to chemo or XRT. In these patients, the use of radiotheranostics is becoming more prevalent and are now being tested in earlier lines of therapy. We have identified an increase in DDR-somatic variants post lutetium-177-PSMA, raising concern for long term hematologic safety. Here, we evaluate the spectrum of CH and CCUS (clonal cytopenias of undetermined significance) in mPC patients, prior to receiving radioisotope therapies. Methods We performed error corrected next-generation sequencing (NGS) on peripheral blood samples from 67 mPC patients enrolled in the Prostate Cancer Medically Optimized Genome Enhanced Therapy Study (PROMOTE) study (NCT #01953640). All patients enrolled also had whole exome sequencing (WES) performed on initial metastatic biopsies and on whole blood for germline genotyping. Somatic variants with a variant allele fraction (VAF) ≥0.5% were considered as CH, using standard bioinformatic variant calling algorithms. Results The median age at NGS was 74.4 years (range, 58.4-92.3). While all patients received androgen deprivation therapy (ADT) +/- androgen receptor pathway inhibitor (ARPI), 67.2% (n=45, pelvic XRT- 35, palliative XRT- 10) received prior XRT and 3% (n=2) received prior docetaxel. No patients in this cohort received prior platinum or PARP inhibitor. Of those treated with XRT or chemo, the median time from first exposure to CH sample collection was 4.1yrs (range, 0.12-29.6) and 2.3yrs (range, 0.6-4.0), respectively. Of the 67 patients, we identified a total of 111 pathogenic variants in 59 (88.1%) patients. We compared our NGS data to the germline data and tumor for each patient (All samples obtained at the same time point; Wang et al 2018). Our analysis excluded 2 ATM variants likely to be germline, and 1 TP53 variant likely to be tumor-derived. Each patient had at least one somatic variant, with a median of 2 variants (range, 1-6The median CH VAF was 1.8% (range, 0.5-50.2) with 91.0% of alterations detected at a VAF of <10%. Specific somatic variants, presence/absence of CH, number of variants, nor VAF was associated with age, prior chemo, or XRT exposures. At time of NGS, 54% of patients were anemic (hgb <13g/dL), 7% were thrombocytopenic (platelets <135 x109), 6% were leukopenic (WBC <3 x 109), and no patients were neutropenic (ANC <1 x109). Persistent cytopenias, lasting >3months, were present in 25% (n=17) of patients; however, bone marrow biopsies (BMB) were performed only in 6% (n=4). Three (75%) of these 4 patients had mPC infiltration in the BM, and 1 (25%) had mild dysplasia not meeting criteria for MDS but meeting criteria for CCUS (CHEK2 somatic variant). At last follow-up, there were no patients formally diagnosed to have myeloid neoplasm (MN). Median overall survival (OS) from prostate cancer diagnosis was 8.6yrs (range, 1.4-28.4). With a median follow up of 2.2yrs (range 0.1-10.8) after CH testing, 3.0% (n=2) were alive, with most deaths occurring due to mPC. The presence of CH did not impact overall survival (OS), however, presence of cytopenias at the time of NGS testing was associated with worse outcomes (median OS 2.5yrs vs 1.2 yrs., p=0.025). Conclusions We define the landscape of CH mutations in mPC patients predominantly treated with ADT/ARPI and XRT, demonstrating that DNMT3A, TET2, PPM1D and ASXL1 are frequently mutated (88%) and largely subclonal (91% with VAF ≤10%). While 25% of these patients had cytopenias, with cytopenias negatively impacting survival, due to inadequate BM biopsy work up, the true prevalence of CCUS and MN could not be estimated. Given the advancement of genotoxic therapies and the high prevalence of subclonal CH in mPC, future studies investigating CH as a predictive biomarker of hematological dysfunction are much needed.
Preliminary Safety and Efficacy of Emavusertib (CA-4948) in Combination with Ibrutinib in Relapsed/Refractory Primary Central Nervous System Lymphoma Patients with Prior Exposure to BTK Inhibitor
Background Primary Central Nervous System Lymphoma Patients (PCNSL) is a rare and aggressive form of NHL in the central nervous system or vitreoretinal space. Despite high initial response rates of high dose methotrexate-based regimens, most patients will relapse in less than two years with poor prognosis. There are no approved treatments for Relapsed/Refractory (R/R) PCNSL, representing a clear unmet medical need. IRAK4 kinase activity is required for TLR and IL-1R signaling in a variety of myeloid and lymphoid cell types, including PCNSL. Recruitment of IRAK4 to these receptors and subsequent activation is facilitated by the MyD88 adaptor protein, which is mutated in ~70% of PCNSL. This leads to constitutive activation of the NF-κB signaling pathway, increased inflammation, and tumor growth. Emavusertib is a novel and potent oral inhibitor of IRAK4, which has demonstrated the ability to cross the blood-brain barrier in PCNSL xenografts. In preclinical studies, the combination of emavusertib with Bruton tyrosine kinase inhibitors (BTKi) showed in vitro synergy of inhibition and re-sensitization of BTKi-resistant cell lines. Emavusertib + ibrutinib has demonstrated an acceptable safety profile across a broad population of R/R NHL patients, including PCNSL. Aim We present updated safety and efficacy of emavusertib in combination with ibrutinib in patients with R/R PCNSL most recently treated with BTKi regimen. Methods The safety, clinical activity, and potential biomarkers of emavusertib in R/R PCNSL are being investigated in the ongoing open-label, Phase 1/2 TakeAim Lymphoma trial (NCT03328078). The eligible patients with R/R PCNSL received emavusertib (100-300 mg BID) in combination with ibrutinib (560 mg QD) continuously until tumor progression or unacceptable toxicity. Disease staging at screening and anti-cancer therapeutic responses were evaluated according to the IPCG Response Criteria Guideline for PCNSL. Results As of 10 July 2024, 13 R/R PCNSL patients, with prior BTK exposure, received emavusertib at 100 - 300 mg BID in combination with ibrutinib at 560mg QD. The median age was 60 years (range 44 - 79). The median number of prior lines of anti-cancer therapies was 2 (range 2 - 5). Median emavusertib/ibrutinib treatment duration was 51 days (range 17 - 503). The preliminary efficacy data in 12 evaluable patients whose most recent treatment regimen included a BTKi and were treated with the combination of emavusertib and ibrutinib showed 3 complete remission (CR), 1 unconfirmed complete Response (CRu) and 2 partial responses (PR) and an overall response rate of 50%. Treatment is on-going for 5 patients with one patient pending the first assessment. All responders demonstrated more than 80% reduction in target lesion size compared to baseline. Two of the responders with a CR demonstrated durable response, with 1 patient having a duration of response (DOR) of approximately 9 months, and the second patient having a DOR of 12 months with response ongoing. Grade ≥3 Treatment-emergent adverse events (TEAEs) were reported in 7 (53.8%) patients, while Grade ≥3 treatment-related adverse events (TRAEs) were reported in 4 (30.8%) patients. No fatal TRAE were reported and the majority of Grade ≥ 3 TEAEs and all Grade ≥ 3 TRAEs were reversible and manageable. Conclusion Emavusertib in combination with ibrutinib shows promising efficacy and was well tolerated with an acceptable safety profile in R/R PCNSL patients with prior BTKi exposure. The combination of emavusertib + ibrutinib may overcome BTKi resistance and has the potential to show improved anti-cancer activity. Enrollment in this trial is ongoing (NCT03328078).
Identifying the Care Gaps in Heparin-Induced Thrombocytopenia Testing Around the COVID-19 Pandemic
Introduction: Heparin induced-thrombocytopenia (HIT) is a severe autoimmune reaction to heparin that increases patients' risk of developing venous thrombosis, leading to fatal conditions such as pulmonary embolism. The clinical 4T scoring system guides need for further testing, based on noting fall in platelet counts, the timing of platelet counts falling in conjunction with heparin exposure, the presence of new thromboses, and ruling out other causes of thrombocytopenia. In patients in whom 4T scoring indicates a higher protest probability for HIT, screening is then performed. The Enzyme-Linked Immunosorbent Assay (ELISA) detects antibodies against platelet factor 4 (PF4)-heparin complexes. In order to confirm the diagnosis of HIT, the serotonin release assay testing is required, which refers to measuring the serotonin levels produced during platelet activation using radio-labeling techniques. Since the start of the COVID-19 Pandemic in 2020, there has been ongoing discussion regarding whether incidence of HIT diagnosis has increased. Herein we report on a retrospective observational study of a cohort of patients seen at a community hospital in Georgia between March 2017 to December 2022 to determine the changes in frequency of HIT and SRA testing, and to assess its association with the COVID-19 pandemic. Methods: We included patients aged >18 years, hospitalized at a community hospital in Georgia during the study duration and de-identified data was collected from electronic medical records. Text-based data analysis was performed to identify those patients who received HIT testing, SRA testing, and ultimately a final diagnosis of HIT (HIT positive and SRA positive). The overall rates of 4T scoring documentation and assessment in the hospital were also assessed. Several multivariable logistic regression models were constructed to examine factors associated with HIT testing and SRA testing, and their association since the start of the the COVID-19 pandemic (March 2020). Results: A total of 244,457 patients were included in the study population. Of them, 2,375 (0.97% of total) patients were tested with the HIT-ELISA, and only 468 (0.19% of total) patients were tested with SRA. In further subgroup analysis, evaluating the temporal associations of HIT and SRA testing, it was observed that the rate of HIT-ELISA testing increased since the onset of the COVID-19 pandemic, as did the rate of SRA testing (p < 0.000). Notably, of the 2,375 patients who received the HIT-ELISA testing, only 193 (8% of HIT-tested patients) had documentation of clinical suspicion of HIT with the 4T score. Discussion: An increase in HIT and SRA testing has been observed since the start of COVID-19 pandemic, with a notable lack of 4T score data in the study population preceding this testing. This study emphasizes the importance of clinician education regarding the process of accurate HIT diagnosis, which would start with clinical 4T scoring, followed by ELISA testing for screening, and finally confirmed by SRA testing. Further research is warranted to understand the barriers that may exist in providing guideline-directed evaluation of HIT so that targeted interventions can be implemented to ensure high-quality care is delivered to patients.
Targeted Next Generation Sequencing Is Comparable with Metagenomic Next Generation Sequencing in Hematological Malignancies with Suspected Pneumonia for Pathogenic Microorganism Detection
Pulmonary infections are commonly observed in hematologic malignancy (HM) patients.For HM patients with low immune functionality and high susceptibility to pulmonary infections, timely identification of pathogens and administration of correct medications can greatly improve patient outcomes[1, 2].The next generation sequencing can achieve an early diagnosis of respiratory infection.To date, the systematic evaluation of the clinical use of mNGS and tNGS for pneumonia in HM patients has been insufficient. A retrospective analysis was conducted on HM patients with suspected pneumonia admitted to the Hematology Department of The Third Xiangya Hospital between April 2019 and April 2024.A total of 234 patients were identified for analysis,including 126 patients used mNGS to detect bronchoalveolar lavage fluid(BALF)and 108 patients used mNGS to detect BALF.The purpose was to compare the diagnostic efficacy of mNGS and tNGS in pulmonary infection pathogens. The overall microbial detection rate of mNGS and tNGS were 88.9% (112/126) and 93.5% (101/108), respectively. And there was no significant difference between them ( p = 0.217).Viruses,bacteria and fungi accounted for 42.2%(117/277), 33.9% (94/277) and 23.8% (66/277) among the microorganisms detected in mNGS, respectively. Meanwhile,Viruses,bacteria and fungi accounted for 61.0%(147/241), 21.2% (51/241) and 17.8% (43/241) among the microorganisms detected in mNGS.In order to compare the diagnostic and concordance between mNGS and tNGS.We used the final clinical diagnosis as the “gold standard”.The sensitivity, specificity, positive predictive value and accuracy of mNGS were 92.7%,37.5%,91.1% and 85.7%, respectively, compared with 97.9%,45.5%,94.1% and 92.6% for tNGS.Further more,we compared the clinical impact of mNGS and tNGS on antibiotic usage.The mNGS results led to adjustments in antibiotic usage for 63 out of the 126 patients(56.3%). Following these alterations, 56 patients (88.9%) reported significant improvements.In tNGS,there are 59 out of the 108 patients(58.4%%) adjustmented in antibiotic usage and 56 patients(94.9%) reported significant improvements.The total death of mNGS and tNGS were 9.8%(11/126) and 4.0%(4/108), respectively. There were no significant differences between the two groups (P >0.05).Compared to the microbial range detected by tNGS, mNGS detected an additional 14 pathogenic microorganisms, in which had a very low proportion of pathogenic microorganisms (3.6%,4/112), which did not have any adverse effects on the clinical outcomes of patients. Collectively,we found that tNGS is comparable with mNGS in HM patients with suspected pneumonia for pathogenic microorganism detection.What's more,the ability of tNGS in guiding treatment was consistent with those of mNGS.
Arrhythmia in Multiple Myeloma Patients Treated with Hematopoietic Stem Cell Transplantation (HSCT): A Propensity Matched Analysis
Introduction: The incidence of cardiovascular events in the first 100 days post-HSCT was found to be 19%, with arrhythmia having the highest incidence of 12% (p<0.0001). The incidence of cardiovascular events is 6.7% in patients with multiple myeloma treated with HSCT (HSCT-MM) [1]. However, the literature on arrhythmia in HSCT-MM patients is limited. Given the high risk of cardiac events in HSCT patients, we aimed to determine the impact of arrhythmia in patients with HSCT-MM. Methods: We conducted a retrospective analysis using the National Inpatient Sample Database (2018-2021). Adult patients with HSCT-MM who were primarily admitted for life-threatening arrhythmias were identified using ICD-10 codes [2]. We performed propensity matching and multivariate regression, considering a p-value of ≤0.05 as significant. Results: In 14,232 HSCT-MM patients, 168 (1.2%) had arrhythmia. The prevalence of arrhythmia in HSCT-MM patients was higher than in the remaining HSCT recipients (1.2% vs 0.9%, p<0.01). In HSCT-MM, atrial fibrillation (69.6%) and atrial flutter (19%) were the common arrhythmias. Arrhythmia in HSCT-MM patients was more prevalent in those over the age of 60 years (84.5% vs 68.5%, p<0.001), males (72.6% vs 58.2%, p<0.001), and in the White race (84.8% vs 67.3%, p<0.001) compared to those without arrhythmia. Arrhythmia was less common in those with bone marrow dysfunction compared to those with normocellular marrow (anemia 1% vs 1.5%, p<0.01; thrombocytopenia 1% vs 1.2%, p>0.05; neutropenia 0.7% vs 1.3%, p<0.05; pancytopenia 0.9% vs 1.4%, p<0.01). Among the HSCT-MM patients with arrhythmia, long-term anticoagulation was less frequently given than those without arrhythmia (44.6% vs 55.4%, p<0.001). The arrhythmia cohort had less frequent acute kidney injury (19.1% vs 27.5%, p=0.01). The arrhythmia cohort required more vasopressors (2.4% vs 2.1%, p>0.05) but had lower mortality (1.2% vs 4.5%, p<0.05). Patients with arrhythmia had shorter hospital stays (Coefficient -3 days; 95% CI -3.8 to -2.3 days; p<0.001) and lesser hospital charges (Coefficient $-41,200; CI $-55,700 to $-26,600; p<0.001) compared to those without. However, the arrhythmia cohort had higher rates of acute heart failure (17.9% vs 9.1%, p<0.001) and the risk of acute heart failure was also higher in those with arrhythmia (adjusted odds ratio 2.2; 95% CI 1.3 to 3.6; p<0.01). In patients with acute heart failure and arrhythmia, atrial fibrillation was present in 76.7% and atrial flutter in 20%. In patients with acute heart failure and arrhythmia, bone marrow dysfunction was more common than normocellular bone marrow (anemia 22.2% vs 12.8%, p>0.05; thrombocytopenia 38.7% vs 13.1%, p=0.001; neutropenia 18.2% vs 14.3%, p>0.05; pancytopenia 8.7% vs 21.3%, p>0.05). In the arrhythmia cohort, long-term anticoagulation was commonly given in those with acute heart failure compared to those without (53.3% vs 46.7%, p>0.05), and acute kidney injury also occurred more frequently in those with heart failure (26.7% vs 17.4%, p>0.05). Conclusion: Acute heart failure is a serious risk associated with arrhythmia in multiple myeloma patients treated with HSCT, with atrial fibrillation emerging as the most common arrhythmia. It is essential to prevent heart failure in those with arrhythmia, especially in patients with thrombocytopenia. Preventive measures could include more frequent follow-ups and having a multidisciplinary team to manage renal failure, monitor anticoagulation, and ensure rhythm control in these patients. References: Aghel N, Lui M, Wang V, et al.: Cardiovascular events among recipients of hematopoietic stem cell transplantation-A systematic review and meta-analysis. Bone Marrow Transplant. 2023, 58:478-90. 10.1038/s41409-023-01928-22021 ICD-10-CM. Accessed: July 14, 2024. https://www.cms.gov/medicare/coding-billing/icd-10-codes/2021-icd-10-cm.
Clinicopathological Features of Kikuchi-Fujimoto Disease: Retrospective Observational Study
Introduction: Kikuchi-Fujimoto disease (KFD), is a rare inflammatory disease of unknown etiology, typically presenting with transient fever and cervical lymphadenopathy. It is recently classified as a tumor-like lesion in the World Health Organization Classification 5th Edition. There are few large-scale studies on patient demographics and clinical course. This study aims to report detailed clinicopathological features of KFD. Methods: We reviewed 112 cases of KFD diagnosed at Okayama University Department of Pathology and Oncology, Okayama, Japan between 2012 and 2022. Patients who were diagnosed with autoimmune diseases or bacterial/tuberculous lymphadenitis after the initial presentation as KFD were excluded. Results: The average age of the included cases was 29.4 years (range:6 to 77 years) with slight female predominance (n = 51/115, 44.3% for male; n = 61/115, 53.0% for female). For the included cases of 30 years or older, there were more females than males. The cervical lymph nodes were the most commonly affected sites (85%). For the 70 patients who had complete follow-up data available in the electric medical records, the recurrence rate was 23%, without a difference between males and females. Laboratory tests demonstrated significantly lower complement 4 (C4) levels (p = 0.038) and a higher rate of positive antinuclear antibodies (p = 0.007) in the relapsed cases than in the cases without documented recurrence. The mean number of days prior to confirm the diagnosis was 71.5 days. Among the representative lymph node histology classification, proliferative type was the most common (n = 75; 77%), followed by necrotizing (n = 22; 22%), and xanthomatous (n = 1; 1%). The patients with necrotizing type had significantly enlarged lymph nodes (p = 0.047) and longer duration of symptoms (p = 0.009) compared to the proliferating type. Discussion: The present study provides data from a large KFD cohort to provide comprehensive clinicopathological information to date. While KFD is known to predominantly affect female, there were considerably more males up to age 30 than females, Being young and adolescent male KFD patients was associated with atypical features. Future studies are warranted to confirm the findings noted in the results, to clarify clinicopathological differences in the male young adolescent KFD, and further characterize the classical female KFD cases, including histological features, treatment responses, and association with autoimmune or malignant hematology conditions. Conclusion: In this study, we analyzed a large number of KFD cases and clarified characteristics. The comprehensive clinicopathological features provided by the present results may be useful in elucidating the pathogenesis and predicting the clinical course of such clinically challenging cases, including association with autoimmune diseases and its long-term outcomes.
Decitabine Synergizes with Replication Checkpoint Inhibitors in TP53-Mutated Acute Myeloid Leukemia
Introduction Acute myeloid leukemia (AML) with mutated TP53 (TP53MT) is resistant to chemotherapy and has a poor prognosis. Prior reports suggest that DNA methyltransferase inhibitors (DNMTi), such as decitabine and azacitidine, form covalent DNA-DNMT1 adducts and invoke a DNA damage response (DDR) characterized by activation of the ATR-CHK1 pathway, including in TP53MT AML samples. This study evaluates whether decitabine exhibits cytotoxic synergy with replication checkpoint modulators (ATRi, CHK1/2i, WEE1i) in pre-clinical models of AML. Methods Parental cell lines (U937, KG1a, Molm13, MV-4-11) were obtained commercially and genomically validated. The Molm13 TP53-/- cell line was generated via CRISPR/Cas9 knockout. Cells were maintained in RPMI-1640 medium with 10% FBS, 2 mM glutamine, and antibiotics at 37 ºC, 5% CO2. Decitabine, ceralasertib (ATRi), prexasertib (CHK1/2i), MK-8776 (CHK1i), and adavosertib (WEE1i) were reconstituted at 10 mM in DMSO. For drug treatments, cells were cultured for 48 h in medium with 0.2% (v/v) DMSO or drug. Western blots were stained with commercial antibodies followed by peroxidase-coupled secondary antibodies and imaged by chemiluminescence. Apoptosis assays were performed via flow cytometry (BD FACSCanto II) with annexin V-APC (BD Biosciences) and/or propidium iodide (Sigma) staining. Peripheral blood and bone marrow samples were obtained from AML patients after informed consent at Mayo Clinic and Johns Hopkins University. Mononuclear cells were isolated via Histopaque-1077 (Sigma) centrifugation and used immediately. Colony forming assays were performed in Methocult H4435 (Stem Cell Technologies) supplemented with vehicle or drug; leukemic colonies were counted after 12-16 days. Combination indices (CI) were determined by the Chou-Talalay method (CalcuSyn) where values <1 indicate synergy and >1 antagonism. This work was supported in part by R01 CA289285. Results Western blots of TP53MT AML cell lines (U937, KG1a) and primary samples treated with decitabine (≤200 nM) for 24 h demonstrated increased phosphorylation of H2AX and S296/S345 CHK1, consistent with activation of the ATR-CHK1 DDR pathway. These changes were less pronounced in TP53 wild type cell lines (Molm13, MV-4-11). In subdiploid (SubG1) assays, U937 cells exhibited resistance to monotherapy with decitabine (EC50 = 330 ± 200 nM) and variable sensitivity to ceralasertib (250 - 500 nM), prexasertib (1 - 10 nM), MK-8776 (250 - 1,000 nM), and adavosertib (50 - 400 nM). When combined, however, marked synergy was observed between decitabine and both ceralasertib (mean CI 0.15) and adavosertib (CI 0.59). Synergy was also observed with the selective CHK1i, MK-8776 (CI 0.56), but less-so with the dual CHK1/2i, prexasertib (CI 0.93), consistent with the hypothesis of an ATR-CHK1 DNA damage response. Similar results were obtained from decitabine (EC50 = 300 ± 100 nM) and ceralasertib (CI 0.54), adavosertib (CI 0.67), MK-8776 (CI 0.52), and prexasertib (CI 0.81) in annexin V assays. These combinations were further evaluated (SubG1 assays) in an isogenic pair of Molm13 and Molm13 TP53-/- cell lines. In Molm13 cells, decitabine (EC50 = 23 ± 11 nM) was again synergistic with adavosertib (CI 0.60), but not ceralasertib (CI 1.3) or prexasertib (CI 1.2). In Molm13 TP53-/- cells, however, very little synergy was observed between decitabine (EC50 = 53 ± 22 nM) and ceralasertib (CI 1.5), prexasertib (CI 4.3), or adavosertib (CI 1.0) except for at higher concentrations of adavosertib (400 nM, CI 0.89). Thus, while biallelic TP53 inactivation conferred resistance to DNMTi and checkpoint inhibitors, the degree of resistance was context-dependent and could be partially overcome by WEE1 inhibition. The combinations of decitabine with ceralasertib (n = 2), prexasertib (n = 4), or adavosertib (n = 3) were evaluated in colony forming assays using primary AML samples from newly-diagnosed patients with diverse clinicomolecular profiles. Combination treatment was antagonistic with ceralasertib (CI 2.2), additive with prexasertib (CI 1.0), and synergistic with adavosertib (CI 0.88). Conclusions In multiple cell lines and diverse primary AML samples, decitabine activated the ATR-CHK1 DDR pathway and synergized with ATRi, CHK1/2i, and WEE1i. Amongst these, only the combination of decitabine plus adavosertib exhibited synergy across all three models, highlighting WEE1 as a potential target in TP53MT AML.
Genetic and Clinical Determinants of Stroke in Sickle Cell Patients: Insights from a Nigerian Cohort
Introduction: Sickle cell disease (SCD) is prevalent in sub-Saharan Africa. Phenotypic diversity in patients with similar SCD genotypes may result from genetic and environmental factors. Nigeria has the highest SCD prevalence, with homozygous SCD (HbSS) being the most severe form. Stroke affects about 11% of children under 20 years with SCD (Ohene-Frempong, Weiner, et al. 1998), primarily ischemic, involving medium to large intracranial arteries. Specific single nucleotide polymorphisms have been linked to ischemic stroke risk in some populations. (Earley, Kelly et al. 2023). This study aimed to identify genetic factors associated with early-age large-vessel stroke in SCD using whole-exome sequencing (WES) in a Nigerian cohort. Methods: The protocol was approved by the IRBs of TJU, Nemours, and 3 Nigerian sites. Subjects with SCD who experienced large vessel stroke early in life (16 years or less) were enrolled, along with controls (SCD patients without stroke). Subjects were recruited from 3SCD clinics in Kano Metropolis, Nigeria. Inclusion criteria were confirmed SCD diagnosis (SS and Sβ0 thalassemia genotypes), abnormal transcranial doppler (TCD) measurements, and clinical evidence of stroke confirmed by MRI by age 16. Controls included SCD patients (SS and Sβ0) aged 16-26 years without clinical stroke and at least one normal TCD. All cases underwent Magnetic Resonance Angiography (MRA) to establish arteriopathy. Immediate family members of subjects >16 years (siblings and parents) were used per best practice trio analysis to annotate variants with appropriate Mendelian inheritance patterns. WES was performed using SureSelect XT HS (Agilent) and Human All Exon V7 Rev B capture probes for library preparation on all samples. Libraries were sequenced on a NextSeq 550 to 50M paired-end 150bp reads. Variants were called using the GATK suite of algorithms following best practice guidelines and annotated using the VarSeq algorithm, including AlphaMissense annotations. Results: The control group had a median age of 21 years, and the stroke group had a median age of 9 years. The stroke group had a higher proportion of males (60%) compared to controls (30%) (p < 0.05). Fifty percent of the stroke group and 73% of the controls had a history of acute chest syndrome. History of avascular necrosis (7.5%), heart disease (2.5%), and splenic sequestration (1.3%) were present only in controls. Malaria (1.3%), sepsis (2.5%), and hand-foot syndrome (59%) affected the stroke group. History of priapism (6.3%) and leg ulcers (10%) had similar rates in both groups. Using AlphaMissense annotations, nine genes were identified to have more damaging mutations in the stroke cohort compared to the control cohort (odds ratio > 1 and p < 0.05). Pathway enrichment analysis utilizing genes prioritized with an odds ratio > 1 identified cadherin signaling, cellular junction/adhesion, and WNT signaling as significant (p < 0.05). The role of cellular adhesion has been previously described in SCD stroke subjects (Oni, Brito et al. 2024). The genes that we found that showed significance in our analysis include ADAMTSL2, ADCY9, OR3A1, OR3A2, XRRA1, ABTB2, CLDN18, CPNE7, EIF3A, SLC7A6, UBA7, PDE6A, GLOD5, and PCDHA1. Conclusion: Genes in the ADCY9 and ADAMSL2 families have been reported in previous studies to be associated with ischemic stroke. Though the small sample size limits this study, it offers preliminary insights into the genetic and clinical determinants of stroke in SCD patients in Northern Nigeria. The identified candidate genes potentially hold biological significance for the stroke phenotype; however, additional research with a larger sample size is required to validate these associations. These findings underscore the need for further whole-exome sequencing studies in Nigerian patients with the stroke/arteriopathy phenotype, which may augment our understanding of this severe complication. An in-depth examination of the genetic modifiers associated with stroke in SCD could lead to enhanced predictive models and targeted preventive interventions, reducing the burden of stroke in affected individuals. Our team has identified additional datasets in the United States to help validate molecular signatures of interest, inspiring us to continue our work in this important field.
Autologous Stem Cell Transplantation for Multiple Myeloma Patients Whose Myeloma Defining Event Was Slim
Background In 2014, the IMWG updated the criteria for diagnosing multiple myeloma (MM) and added three additional criteria to the traditional CRAB criteria. The new criteria called the SLiM criteria, include clonal bone marrow plasma cells ≥60%, involved to uninvolved free light chain ratio (rFLC) ≥100 (involved FLC must be ≥ 100 mg/L), and > one focal lesion on MRI studies (each lesion ≥ 5 mm). These criteria were deemed myeloma-defining events (MDE) in the absence of CRAB criteria. Autologous stem cell transplantation (ASCT) has been used for treating MM for over three decades and is safe and efficacious. We report on outcomes of outpatient ASCT in a cohort of patients with MM where therapy was initiated solely based on SLiM criteria. Methods We conducted a retrospective study of all patients diagnosed with MM based on SLiM criteria at Mayo Clinic, Rochester, MN. We compared this cohort to a matched cohort of newly diagnosed MM patients whose MDE was CRAB and who underwent an ASCT. For every patient whose MDE was SLiM, we matched two patients whose MDE was CRAB. The matching was done by age, gender, and melphalan dose. Results Between 2013 and 2022, 30 patients received an ASCT due to SLiM criteria at Mayo Clinic, Rochester (Durie Salmon Stage IA). The median age of our cohort was 63 (range 46-75) years, and 60% had an ISS of 1. Seventeen percent of the cohort was treated with DVRd induction. The median time from diagnosis to ASCT was 6.5 months (IQR 6-7), and all but one received full intensity conditioning with melphalan 200 mg/m2. 53% of patients completed the ASCT without requiring hospitalization, and 47% (n=14) of patients required hospitalization with a median duration of hospital admission of 6 days (IQR 5-14). Bacteremia was confirmed in 7 patients (23%). The matched cohort included 60 patients. Baseline characteristics were similar, with the exception of lower hemoglobin levels in the control group, as expected (13.1 vs 12, P=0.0017). No differences were seen in the number of cells collected (3.4 vs 3.67 X106 cells/kg, P=0.19) or the use of Plerixafor (80% vs 78%, P=0.8). The SLiM cohort had a shorter median time to neutrophil (15 vs 16 days, P=0.049) and platelet (15 vs 17 days, P=0.0004) engraftment. Similar hospitalization and bacteremia rates were seen. The overall response rate was 100%, with a complete response or better (sCR/CR) seen in 30% of patients. The matched cohort had an ORR of 98%, with sCR/CR of 37%. The MRD- rate was the same in both groups. More patients in the SLiM cohort achieved VGPR (50%) than in the CRAB cohort (27%). None of the patients died within 100 days of transplant. The 36-month OS was 100% in the SLiM group and 93.3% in the control group (95% CI 83.1%-97.4%), with a trend towards higher OS in the SLiM cohort (P=0.065). The 36-month PFS was 91.61% in the SLiM cohort (95% CI 69.93-97.87%) and 65.95% in the control group (95% CI 52.31%-76.53%). There was no difference in the PFS between the cohorts (P=0.414). Conclusion ASCT is efficacious and safe in MM patients transplanted only due to SLIM criteria. Improved MRD- and longer PFS were not seen despite lower ISS stage disease in the SLiM group.