Morphological Variations of the Lungs: A Cadaveric Study

The lungs are the organs of respiration which are situated on either side of the heart and other mediastinal contents in its pleural cavity. A fresh lung is spongy, can float in water and crepitates when handled. Lungs are important with respect to its blood circulation. The lungs are divided by fissures into lobes which facilitate movements of lobes in relation to one another. The hilum of each lung is its gateway. In the present study, we aim to assess the morphological variations of human cadaveric lungs at Chitwan Medical College (CMC). An observational study was conducted at dissection hall of anatomy department at Chitwan Medical College from September 2019 to October 2020 after taking ethical approval form Institutional Review Committee of CMC. All the intact 70 lungs present in the department were studied. Photographs of the intact lungs were taken from different surface. The lungs were porus, highly elastic and spongy in texture. On keeping lungs to water tank it got floated. We found 34(80.96%) of the studied specimen of right side had horizontal fissure present in it. The remaining 8 (19.04%) specimens did not have horizontal fissures, while 3 (5.88%) specimens had incomplete fissures. The oblique fissure was not present in 2 (2.38%) of the study specimens. The left side of the study specimen has a variance of 1(4.16%). When the hilum right lung was examined, 40 (95.23%) of the structure had the usual organization pattern. In the left lung, the usual pattern of organization was 21(75%). The differences are thought to be present in the lung’s fissure and hilum. The current study’s findings are therapeutically important. The findings could prove beneficial to cardiovascular and thoracic surgeons.

Manifestations of intraocular inflammation over time in patients on brolucizumab for neovascular AMD

Purpose To describe the adverse events associated with brolucizumab, in particular the sequence of intraocular inflammation (IOI), retinal vasculitis (RV), and/or retinal vascular occlusion (RO). Methods This was an unmasked post hoc analysis of the randomized HAWK/HARRIER clinical trials. Patients with neovascular AMD in the brolucizumab arms of the trials were included. IOI-related adverse events reported by study investigators were analyzed to determine early signs and the time course of IOI-related adverse events, using a subgroup of patients with definite/probable IOI cases identified in an independent unmasked post hoc review by an external safety review committee. A limited literature review on IOI following anti-VEGF therapy was also conducted. Results Among 50 patients with definite/probable IOI cases identified by the safety review committee, 12 had RV or RO adverse events reported by the investigators. For 6 of 12, IOI (other than RV) was reported before RV or RO. The duration from the first IOI adverse event to the first RV or RO adverse event ranged from 16 to 171 days for 5 patients and was 553 days for 1 patient. Four of the 6 patients received ≥ 1 brolucizumab injection on or after the date of the first IOI adverse event and before the first RV or RO adverse event. Conclusions IOI may precede RV or RO in some patients treated with brolucizumab.

Translation and Cross-Cultural Adaptation of the Delphi Definitions of Low Back Pain Prevalence into Swedish (Swedish DOLBaPP)

Background: Previous studies on the prevalence of low back pain have found large variations between different population-based studies. The use of different definitions could partly explain these differences. In a Delphi study 28 experts in back pain research agreed on standardized items: the "Delphi Definitions of Low Back Pain Prevalence” (DOLBaPP). The Delphi DOLBaPP needs to be adapted to different languages and cultures. The aim was to translate and cross-culturally adapt the English definitions and corresponding Delphi Definitions of Low Back Pain Prevalence (DOLBaPP) questionnaire forms into Swedish.Methods: Translation and cross-cultural adaptation of the Delphi DOLBaPP into Swedish was conducted following recommended guidelines. After the translation process, an expert committee including medical and language experts independently provided comments on the questionnaire. The pre-final online optimal questionnaire was pretested in 181 employees from the home care, education, and food and retail sectors.Results: The DOLBaPP questionnaire forms were translated successfully into Swedish and cross-culturally adapted with few linguistic changes. Face validity of the translated version of the questionnaire was considered good by the expert committee. In question 2 about low back pain, the expression "was this pain bad enough" was re-worded into "was the pain so strong". In the pre-test 92% of the participants found the questions in the questionnaire clear, 86% that the questionnaire covered the subject adequately, and 88% needed less than five minutes to complete the questionnaire. Fifteen percent had comments including linguistic issues and issues of expanding the content. The comments were not interpreted by the review committee as improving the language nor targeting the aim. After the pre-test, consensus was reached in the review committee on the final DOLBaPP-S.Conclusions: The translation and cross-cultural adaptation of the Delphi Definitions of Low Back Pain Prevalence into Swedish was successful, and the DOLBaPP-S can be used in epidemiological studies on the prevalence of LBP in Swedish speaking populations.

Transdisciplinary Teaching and Learning in UX Design: A Program Review and AR Case Studies

Today’s user experience (UX) educators and designers can no longer just focus on creating more usable systems, but must also rise to the level of strategists, using design thinking and human–computer interaction (HCI) solutions to improve academic and business outcomes. Both psychological, designer, and engineering approaches are adopted in this study. An invited program review committee met to review progress of the UX program at the Beijing Normal University (BNUX). They considered issues and challenges facing the program today, and the steps that it could make to develop further. During a recent augmented reality (AR) project on designing future life experience on smart home and wearables, several experiential concepts and prototypes were generated to demonstrate HCI and UX research directions. The committee was impressed by BNUX with its energy, enthusiasm, and a sense of purpose on practicing transdisciplinary teaching and learning activities. Recommendations on the current organization of education, the relation between project-based learning and research, and opportunities for exposure and visibility are provided.

Deficiency of RPS14 Beyond the Haploinsufficient Loss in Del(5q)

The prevailing theory in del(5q) is that haploinsuffciency (HI) stemming from deletion and not simply LOH (loss of heterozygosity) is the culprit in clonal evolution. To date no haploinsufficient gene has been found to be the leukemogenic factor conveying growth advantage, but various other genes have been found to be important for phenotypic features or for propensity to acquire subsequent specific lesions. RPS14 is an example of such a gene, particularly in patients (pts) with isolated del(5q), responsible for macrocytic anemia and erythroid dysplasia and a propensity for acquisition of TP53 mutations. We hypothesized that RPS14 downmodulation and its consequences may be more common than del(5q) and it is frequent pathophysiologic feature in MDS. We first analyzed the genomic and expression profile of 170 pts with del(5q) and 825 diploid for 5q. We developed a new analytic pipeline to identify the most HI genes present in a large number of del(5q) pts. Genes within CDR (common deleted region) were classified as HI from the linear model fit if (i) clonality vs. gene expression slope from the isolated del(5q) was negative and FDR<.05; and (ii) effect of del(5q) at 50% clonality vs. other cases was negative and FDR<.05. A total of 62 genes met these criteria for linear-model based genes HI status, with a further 5 genes dropping due to low expression. Gene expression for these 57 HI genes among del(5q) samples was adjusted to 50%-clonality using the slopes from the estimated linear model to remove clonal heterogeneity. After applying model-based sparse clustering approach on all cohort, we obtained 7 clusters (Figure 1). As expected, del(5q) cases clustered together and showed consistent HI of 5q marker gene expression. Cluster-1 (n=146) included almost all del(5q) cases, except for 8 "mis-categorized" patients. It was characterized by low risk MDS (LR-MDS), presence of anemia/neutropenia and low mutational burden, with TP53 being the most commonly mutated gene and the only cluster with CSNK1A1 mutations. The remaining non-del(5q) patients were grouped in 6 clusters. Diploid cluster-2 (n=133) featured a normal karyotype, frequent ASXL1 and TET2 mutations, and profound down-modulation of RPS14 in all the patients included in the cluster (vs. other diploid pts). While the median RPS14 expression in cluster-1 (del(5q) cluster, with 50% adjusted clonality) was 7.29 (range 4.68-8.82 Log 2CPM), cluster-2 exhibited a median RPS14 expression of 6.12 Log 2CPM (range: 4.91-7.31 Log 2CPM). Clusters-3, -4, -5 (n=138, 90, 94, respectively) included most of the high risk MDS (HR-MDS). Cluster-3 was enriched for thrombocytopenia and SRSF2 mutations; cluster-4 for anemia, thrombocytopenia and ASXL1 and SRSF2 mutations. Cluster-5 was characterized by pancytopenia and frequent ASXL1 mutations and CK (complex karyotype). Cluster-6 (n=66) and -7 (n=233) contained the majority of non-del(5q) LR-MDS. When we analyzed the RPS14 expression in these clusters based on the RPS14 expression in cluster 2 we found 13% (n=18), 21% (n=19), 9% (n=8), 14% (n=9), 7% (n=16) of low RPS14 expressors in cluster-3, -4, -5, -6, -7, respectively. Cluster-2 showed a similar percentage of patients with anemia, and thrombocytopenia vs. Cluster-1 (69 vs. 50%, 23 vs. 30%; respectively). The mutational profile included a higher frequency of mutations for SRSF2 (29 vs. 0%), NRAS/KRAS (22% vs. 4%), ASXL1 (40 vs. 15%), TET2 (35 vs. 15%), and JAK2 (17 vs. 6%). These results indicate a more proliferative molecular spectrum of RPS14 downregulated cluster-2 than del(5q)-cluster-1, but RPS14 downmodulation did not lead to acquisition of TP53 mutations (4% vs. 76%). Considering all non-del(5q) RPS14 low expressors (n=186), only 3% of the cases had TP53 mutations. Since TP53 and CSNK1A1 mutations were characteristic of cluster-1 we studied interactions with HI RPS14. HI RPS14 in del(5q) and diploid low expressors showed a decreased expression of CDKN1A (P<.001) in comparison to the non-HI or low RPS14. We also found that CSNK1A1 mutations were not found outside of del(5q) pts, CSNK1A1 low expressors coincided with RPS14 low expressors. In conclusion, RPS14 expression defect is more widespread than del(5q) in MDS. However, only del(5q) RPS14 HI pts are prone to harbor TP53 and CSNK1A1 mutations; a group of diploid pts with low RPS14 and CSNK1A1 expressions might mimic some del5q features and could potentially respond to similar treatments. Figure 1 Figure 1. Disclosures Diez-Campelo: Takeda Oncology: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Carraway: AbbVie: Other: Independent review committee; Jazz: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Other: Independent review committee; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astex: Other: Independent review committee; Stemline: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene, a Bristol Myers Squibb company: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Haferlach: MLL Munich Leukemia Laboratory: Other: Part ownership. Haferlach: MLL Munich Leukemia Laboratory: Other: Part ownership. Maciejewski: Bristol Myers Squibb/Celgene: Consultancy; Regeneron: Consultancy; Novartis: Consultancy; Alexion: Consultancy.

Effects of Oral Intake of Olive Leaf Extract on Hematological Parameters: A Double-Blinded, Randomized, Placebo-Controlled Trial in Progress

Background: Anemia is one of the major public health problems that affected 2.36 billion individuals worldwide in 2015. Half of all causes of anemia are iron or other nutrient deficiency anemia (WHO, 2015). Currently available treatment options for anemia include iron or other nutrient supplementation, nutritional interventions in the form of food fortification, blood transfusion, and erythropoietic agent infusion. However, conventional treatments are not without adverse effects. In this context, medicinal plants with bioactive components have been receiving considerable attention from researchers as natural hematinic agents complemented with or alternatives to conventional treatment. Olive leaf (Olea europaea L. Oleaceae) extract (OLE) is rich in bioactive compounds and have been reported to have several health benefits (Gorzynik-Debicka et al., 2018). Previously we showed that apigetrin and apigenin, components of OLE, induced erythroid differentiation in K562 cells (Tsolmon et al., 2011 and Isoda et al., 2014). Also, OLE and its phenolic compounds induced erythroid differentiation in hHSCs (Kondo et al., 2021, Samet et al., 2015). Additionally, we have reported that long-term consumption of OLE tea increased RBC count, Hb%, and hematocrit (Ht) in female volunteers aged between 40 - 70 years old (Ferdousi et al., 2019). However, none of the participants were anemic at the baseline. Therefore, in the present study, we aimed to investigate the effects of oral intake of OLE on hematological parameters in healthy to mildly anemic young adults. Study Design and Methods A double-blinded, randomized, placebo-controlled study will be conducted in Bangladesh. Total 165 apparently healthy adults with Hb level at least 10g/dl for females (nonpregnant, non-breastfeeding) and 11g/dl for males, and aged between 18 to 59 years will be enrolled from the local community. Major exclusion criteria will include currently pregnant women or breastfeeding mothers, moderate to severe anemia (Hb concentration < 10 g / dL for women and < 11 g / dL for men), any medical condition, such as hematological diseases, malignant tumors, aplastic anemia, uncontrolled hypertension, chronic kidney disease, irritable bowel syndrome, and cardiovascular diseases, and currently taking medicine for diabetes or hypertension and taking regular iron or other supplements, etc. After providing informed written consent, study participants will be randomly assigned to placebo, 250 mg OLE and 500 mg OLE groups. Participants will take OLE or placebo capsules in two divided doses every day for 12 weeks. Hematological parameters, Hb concentration, RBC count, WBC count, Ht, MCV, MCH, MCHC, serum Fe and ferritin levels will be investigated at baseline and after 6 and 12 weeks of intervention. Liver and renal function tests will be conducted for safety assessment. Additionally, lipid profile will be investigated to understand how lipid parameters will be regulated if anemia condition is improved by OLE intervention (Araki et al., 2019). Given that fatigue is one of the most common symptoms of anemia, we will also evaluate the effect of OLE on the score of each item of the Fatigue Assessment Scale (FAS) questionnaire during the intervention. The analysis will be carried out on an intention-to-treat basis involving all the participants who will consume the test samples at least once. We will replace the missing data from dropouts using the baseline observation carried forward method. ANOVA with Bonferroni's post hoc test will be used for normally distributed data; otherwise, the Mann-Whitney U test or Kruskal-Wallis H(K) test will be used. Categorical variables will be compared by the Chi-square or Fisher's exact test. A one-way repeated-measures ANOVA with Bonferroni's post hoc test (Within-group) and ANOVA followed by Bonferroni's post hoc test (between-group) will be performed. Significance is at p < 0.05. This protocol is registered with UMIN-CTR Clinical Trial (UMIN000039023), and has been approved by University of Tsukuba Hospital Clinical Research Ethics Review Committee (R01-292) and the Ethical Review Committee of icddr,b (PR-21017). This study is funded by the Japan Society for the Promotion of Science (19K20106) and partly by the Japan Science and Technology Agency-SATREPS (JPMJSA1506). Disclosures Suidasari: Nutrition Act Co. Ltd.: Current Employment. Yokozawa: Nutrition Act Co. Ltd.: Current Employment. Yamauchi: Nutrition Act Co. Ltd.: Current Employment.

Genomic Landscape of PHD Finger Protein 6 (PHF6) Mutant Myeloid Neoplasia

Clinical impact and mechanistic contributions to leukemogenesis are difficult to assign to less common somatic mutations. However, the genetics of inherited syndromes can often be helpful in discerning the biological functions and mechanistic consequences of genes in other diseases. PHF6 (Xq26.2) encodes a protein consisting of two PHD-type zinc finger domains with activity in transcriptional regulation. PHF6 translocations were originally described in T-ALL and its mutations were later observed also in CML and adult AML. Germline (GL) PHF6MT cause Börjeson-Forssman-Lehmann syndrome (BFLS), an X-linked disorder characterized by intellectual disability and, to date, only a few BFLS cases were found to develop lymphoma or T-ALL. While regularly encountered in myeloid neoplasia (MN), the impact and functional meaning of PHF6 are not well established. To determine the incidence, distribution and molecular context of PHF6MT we studied a large cohort of patients with MN (n=8617) collected from our institution and public series. 1 Overall, 73% of patients were AML (pAML 69%; sAML 4%), MDS (22%) and MDS/MPN (5%) with a median age at diagnosis of 67 ys (18-100). We detected 149 patients (2%) carrying at least 1 PHF6MT with 11 harboring more than 1 hit. Four patients carried -X in addition to PHF6MT (2 males; 2 females). Majority of patients (68%) carried frameshift del/ins and nonsense. Mutations were scattered across all coding region with a slightly enrichment (47%) in the second PHD domain (239-330 aa) including the frequent R274Q/X (n=17). Common hits mainly affected arginine residues essential for DNA binding capacity (R129X n=9, R116X=7, R319X=5, R225X=3) followed by other hits (I314T=6, Y301X and C20fs=4 each). Of note, R116X, R225X, R274X, C280Y, H329R and Y303* lesions overlapped with the T-ALL PHF6MT spectrum while no overlap was found with GL mutations found in BFLS. Overall, 75% of all PHF6MT carriers were males and carried mostly (80%) truncating lesions. Compared to mutational frequencies observed in other X-linked genes, truncating PHF6MT behaved similarly to those in ZRSR2 (78%), STAG2 (73%) and BCOR (62%). Conversely, BCORL1MT, KDM6AMT and PIGAMT were evenly distributed between genders. When evaluating mutational characteristics in males and females, no differences were found in sex-adjusted median variant allelic burden of PHF6MT (54.8 vs 51%) nor its mRNA expression levels suggesting locus inactivation. PHF6MT tended to be older than PHF6WT patients (72 vs 68 ys; P= .05) and had mostly (63%) AML followed by MDS (23%) and MDS/MPN (14%). OS was similar between PHF6MT and PHF6WT patients (P= .16). Expression analyses showed that PHF6 loss leads to deregulation of chromatin and transcriptional factor genes. Indeed, in our cohort the most comutated genes were transcriptional factors and chromatin modifiers genes such as RUNX1 (26/149, 17%), ASXL1 (23/149, 15%) and TET2 (17/149, 11%). Of note, this group characterized by the triple ASXL1, RUNX1, TET2 mutational configuration clustered in one of the genomic groups previously identified (GC-3) 1 but the presence of these lesions did not worsen the OS as compared to PHF6MT without this mutational constellation. A low frequency of SF3B1MT (4%) was also noted confirming the enrichment of PHF6MT in AML rather than in low risk MDS. Further, 12% (14 males; 4 females) of PHF6MT patients had X-mutation mosaicism as shown by concomitant hits in BCOR (n=8), ZRSR2 (4), STAG2 (5), KDM6A (1). PHF6MT were equally founder lesions (30%; 44/149) and subclonal (34%; 50/149) whereas the rest was indistinguishable by VAF discrimination (co-dominant). The most common subclonal mutations were U2AF1 (14%, 6/44), IDH1/2 (9%, 4/44) and RUNX1 (7%, 3/44). When PHF6MT were subclonal, the founder hits were in TET2 (14%, 7/50), DNMT3A and RUNX1 (12%, each 6/50) genes. Given the high frequency of RUNX1MT in PHF6MT we investigated whether RUNX1 and PHF6 might be correlated. Transcriptomic analysis of 6246 patients (from 9 public studies) 2 showed a direct linear correlation (AdjR2= .03, P=5.55e-05) between the expression of the two genes. Our study is the largest to date to investigate the genetic landscape of PHF6MT in MN and highlights a strong connection of PHF6 with transcriptional regulation and chromatin genes. Ongoing scDNA-seq will clarify whether these mutations were acquired in distinct clones helping in dissecting the clonal hierarchy of PHF6MT cases. Disclosures Carraway: Celgene, a Bristol Myers Squibb company: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Stemline: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Other: Independent review committee; Takeda: Other: Independent review committee; Astex: Other: Independent review committee; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Advani: Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Research Funding; Glycomimetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Macrogenics: Research Funding; Immunogen: Research Funding; OBI: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Research Funding. Maciejewski: Regeneron: Consultancy; Novartis: Consultancy; Alexion: Consultancy; Bristol Myers Squibb/Celgene: Consultancy.

A Novel Machine Learning-Derived Molecular Classification Scheme with Prognostic Significance

The gold standard for the diagnosis of MDS relies on morphologic alterations hampered by a great deal of subjectivity. Cytogenetic and clinical features allow for clinical classifications predictive of survival. However, with a few exceptions (SF3B1MT, del5q, and certain balanced translocations), neither classic histo-morphology nor prognostic scoring systems (e.g., IPSS-R) are reflective of pathogenic underpinnings. To date supervised analyses of mutational data did not succeed to produce profiles specific or predictive of traditional disease sub-entities. Large cohorts with clinical annotation and a sufficient follow-up allow for innovative biostatistical approaches to subgroup patients according to molecular profiles. Objective operator-independent subcategorization may be congruent with common pathogenic links, rational applications of targeted therapeutics and better prognostications. We hypothesized that machine-learning (ML) strategies used for analysis of mutational/cytogenetic profiles will enable recognition of invariant disease subcategories according to their molecular configurations. Herein, we compiled a meta-analytic database (our cohorts and publicly available sources) of 3,011 MDS (median age 71yrs) and 6,788 pAML/sAML. Results of deep targeted sequencing of a panel of 55 myeloid mutations were collected together with cytogenetics. We then performed unsupervised analysis of MDS and AML patients using Bayesian Latent Class Analysis (BLCA). A consensus matrix was then clustered using Ward's criteria to generate final cluster assignment based on the highest silhouette value. To identify genomic signatures, we used Random Forest classification and extracted mutations with highest global importance indicated by mean decrease in accuracy. Using BLCA we identified 5 unique genomic clusters (GCs) with 3 distinct prognostic outcomes [low risk (LR), intermediate risk (Int), and high risk (HR)] that were validated by survival analysis (Fig.1A,B). The LR group included GC-1 and was characterized by the highest prevalence of normal cytogenetics (100%) and SF3B1 MT (25%) with co-occurring DNMT3A MT (14%), and absence of ASXL1 MT, ETV6 MT, STAG2 MT, TP53 MT, and complex/abnormal cytogenetics. Int group included GC-2 and GC-4. GC-2 was characterized by a higher percentage of abnormal cytogenetics cases than LR group and absence of STAG2 MT, SRSF2 MT, ASXL1 MT, TP53 MT, and normal/complex cytogenetics. GC-4 had the highest frequency of SRSF2 MT (52%) with co-occurring ASXL1 MT (59%), TET2 MT (40%), normal karyotype, and absence of complex/abnormal cytogenetics. Finally, HR included GC-3 and GC-5. GC-3 included ASXL1 MT (67%) with co-occurring SRSF2 MT (47%), TET2 MT (37%), STAG2 MT (22%), and absence of normal cytogenetics. GC- 5 had the highest frequency of -5/del(5q) (50%), -7/del(7q) (43%), -17/del(17p) (16%) and the highest odds of complex karyotype (92%) as well as TP53 MT (48%). Paralleling the genomic ML-based clustering, the clinical relevance of these subgroups was reflected in significantly different survivals [median (95% CI)]: i) GC-1 [69 (59-80)], ii) GC-2 [35 (29-41)], iii) GC-3 [12 (10-16)], GC-4 [27 (22-34)], and GC-5 [9 (7-11)] months (Fig.1C). We then classified the MDS cohort according to the recently published and validated AML GCs (Awada et al Blood 2021) to investigate overlapping genomic features. Overall, 90% of MDS GC-1 and 67% of MDS GC-2 had the same molecular architecture of AML GC-2 and 70% of MDS GC-5 had the same molecular features of AML GC-4. In addition, 98% of MDS GC-3 and 92% of MDS GC-4 had the same features of AML GC-3 (Fig.1D). In sum, we propose a novel objective molecular classification of MDS and related diseases that allows subgrouping of patients according to shared pathogenesis for a better prognostic resolution without errors derived from subjectivity. The model was then internally and externally validated using a cohort of 200 cases. Results of a validation cohort and online URL site of molecular clustering will be presented at the meeting. Figure 1 Figure 1. Disclosures Balasubramanian: Servier Pharmaceuticals: Research Funding. Patel: Alexion: Consultancy, Other: educational talks, Speakers Bureau; Apellis: Consultancy, Other: educational talks, Speakers Bureau. Carraway: Celgene, a Bristol Myers Squibb company: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Astex: Other: Independent review committee; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Other: Independent review committee; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Other: Independent review committee; Stemline: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Haferlach: MLL Munich Leukemia Laboratory: Other: Part ownership. Maciejewski: Regeneron: Consultancy; Novartis: Consultancy; Alexion: Consultancy; Bristol Myers Squibb/Celgene: Consultancy.

Germline and Somatic Variants of CSF3R Define Distinct Myeloid Neoplasia Syndromes

Somatic and germline (GL) variants of CSF3R are found in myeloid neoplasia (MN) and severe congenital neutropenia (SCN). In particular, somatic gain-of-function mutations in the juxtamembrane region of the receptor occur in chronic neutrophilic leukemia (CNL) or secondary AML. Another hotspot for somatic nonsense variants frequently mutated in these categories of pts involves the intracellular domain which regulates inhibitory growth pathways. We hypothesized that the somatic CSF3R variants could reveal previously unrecognized GL SCN mutations. When we studied a cohort of 2,610 pts with MN, we identified a total of 68 CSF3R variants (CSF3RMT). Using a bioanalytic pipeline, we assigned pathogenicity and type of origin (somatic vs. GL) to these variants, particularly those not previously described. In total, we found 32 GL (CSF3RGL) and 36 somatic (CSF3RS) mutations. Of the GL variants, 4 were previously described in pts with SCN consistent with heterozygous loss of function of the CSF3R gene. However, 15 additional alterations were located in similar regions and were predicted to be pathogenic while 13 variants were previously never described. Most of the CSF3RGL mutations were identified in pts with AML and MDS (88%). Interestingly, 2 (6%) pts had co-existing idiopathic neutropenia that progressed to secondary MDS. Another pt had aplastic anemia that eventually progressed to secondary AML. CSF3RGL were most often located in either the intracellular domain (44%) or the extracellular domain (34%) while none of the CSF3RGL mutations were found in the juxtamembrane region (Fig1). AML was detected in 21% of the pts with a CSF3RGL intracellular domain mutation and 18% of the pts with extracellular domain mutations. Of the germline missense variants, E808K (28%), R698C (9%), and E149D (9%) were the most frequently detected. Among the pts with E808K, 22% developed AML. The previously non-reported variants were detected in either the intracellular (50%) or the extracellular domain (50%). Missense variants were detected in 9/10 of the novel mutations in the following locations: L723V (20%), R428K (10%), G731R (10%), V406fs (10%), G687S (10%), P682H (10%), T154I (10%), and S413L (10%). One truncating mutation was found (c.1865-6delC) and it was located in intron 14 and has unknown impact on CSF3R function. Complex karyotype was noted in 19 % of the cases with CSF3RGL. DNMT3A (19%), NRAS (13%), FLT3 (9%), and BCOR (9%), were the most commonly found co-mutations. CSF3R S mutations were all heterozygous and found in 18 pts with AML and 18 pts with MDS and other MN. Overall, these lesions mapped within the intracellular proximal and distal domains (53%), the extracellular domain (14%) the juxtamembrane domain (25%), and the transmembrane domain (8%). Of note, MDS/MPN pts with CSF3RS mutations (11%) had lesions distributed between the intracellular, juxtamembrane and extracellular domains while none of the AML pts had mutations in the extracellular domain. Of all mutations, 36% were truncating events previously described in the context of post SCN AML while 61% were missense mutations. T618I was the most frequent CSF3RS detected (25%), followed by Q749X (11%), Q741X (9%), Q743X (6%). Juxtamembrane hits (CNL-like lesion) were all in the same canonical region (T618I). In contrast, somatic hits otherwise typical for post SCN AML were found in 33% of CSF3RS alterations and included the following: Q749X(4), Q741X (3), Q739X (2), S742X, Q743X, and E405K (not typical for post SCN AML). Taken together the combined allelic burden of these variants did not exceed that of general population (OR: 0.9503) suggesting that they are not significant risk alleles. Of note is that none of these variants were found to be in biallelic (somatic/GL) configurations. Complex karyotype was found in 19% of the pts with CSF3RS followed by del7q in 13% of cases. Importantly, an antecedent history of neutropenia was noted only in 14% of the pts carrying CSF3RS. Regarding associated mutations, ASXL1 (43%), RUNX1 (23%), SETBP1 (23%), TET2 (23%), DNMT3A (17%), SRSF2 (16%), EZH2 (14%), IDH2 (11%), and NRAS (11%) were the most common co-mutations. We have investigated CSF3RS mutations for the presence of GL alterations, but compound heterozygous configurations were not identified. We concluded that CSF3R mutations typically associated with SCN transformation to myeloid neoplasia can occur without GL variants associated with this defect. Figure 1 Figure 1. Disclosures Balasubramanian: Servier Pharmaceuticals: Research Funding. Patel: Apellis: Consultancy, Other: educational talks, Speakers Bureau; Alexion: Consultancy, Other: educational talks, Speakers Bureau. Advani: Kite Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Research Funding; Glycomimetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; OBI: Research Funding; Immunogen: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Research Funding; Macrogenics: Research Funding. Carraway: AbbVie: Other: Independent review committee; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Stemline: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Other: Independent review committee; Astex: Other: Independent review committee; Jazz: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene, a Bristol Myers Squibb company: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Maciejewski: Novartis: Consultancy; Regeneron: Consultancy; Bristol Myers Squibb/Celgene: Consultancy; Alexion: Consultancy.