SUMMARY Lipid droplets (LDs) are the major fat storage organelles in eukaryotic cells, but how their size is regulated is unknown. Using genetic screens in C. elegans for LD morphology defects in intestinal cells, we found that mutations in atlastin, a GTPase required for homotypic fusion of endoplasmic reticulum (ER) membranes, cause not only ER morphology defects, but also a reduction in LD size. Similar results were obtained after depletion of atlastin or expression of a dominant-negative mutant, whereas overexpression of atlastin had the opposite effect. Atlastin depletion in Drosophila fat bodies also reduced LD size and decreased triglycerides in whole animals, sensitizing them to starvation. In mammalian cells, co-overexpression of atlastin-1 and REEP1, a paralog of the ER tubule-shaping protein DP1/REEP5, generates large LDs. The effect of atlastin-1 on LD size correlates with its activity to promote membrane fusion in vitro. Our results indicate that atlastin-mediated fusion of ER membranes is important for LD size regulation.

Incremental improvement in care for children with sickle cell disease (SCD), arising from government-funded research over the last 4 decades, resulted in a dramatically reduced childhood mortality. However, the impact of iterative research and disease modifying therapy (DMT) on adults with SCD has not been as strong. Until now, there has been no coordinated, longitudinal, generalizable, natural history study of SCD that allowed for an assessment of the contemporary adult population. Here, we describe demographics at enrollment and cross-sectional clinical characteristics of 570 adults with SCD (SCA, homozygous HbSS or HbSb0 N=387, 68%, and compound heterozygous SCD variant, HbSC or HbSb+ N=183, 32%, Table I) on whom we have evaluable data. These data are from the multi-site REDCap-based prospective Globin Research Network for Data and Discovery (GRNDaD) registry, comprising 11 centers with over 1100 consented adults and children. The objective of this work was to evaluate the cohort at year of entry, including the use and clinical associations with DMT, and to explore indicators of disease progression as patients age. 16% of adults with SCA and 9.6% with variant disease stroke; 60.9% of adults with SCA and 41% with variant disease had a history of acute chest syndrome. Albuminuria was prevalent in both SCA (39.5%) and variant disease (19.4%). 185 adults (185/387, 47.8%) with SCA, previously referred for symptoms in clinic, had recorded tricuspid regurgitant jet velocity measurements, with a significantly abnormal result (>2.7 m/s), in 92 (92/185, 49.7%). At enrollment, 45% of adults with SCA (175/387) and 14% of adults with variant disease (25/183) were on hydroxyurea (HU); 20.4% of adults with SCA were on chronic transfusions (79/387) compared with 7% of adults with variant disease (13/183). One third of all adults with SCA were not on or were not consistently on DMT, and had laboratory evidence for increased hemolysis (Table 1). Adults with SCA who were on HU had a higher MCV and higher HbF than other treatment states (Table 1). However, only 34% (60/175) of adults with SCA on HU were at maximally tolerated dose (MTD), per guideline-based recommendations, i.e. ANC ≤4.0 x109/L. On HU, those in the lowest quartile for ANC (<3.2 x109/L) were older (mean age 35.9 years (95% Confidence Limit (CL) 32.5-39.3) vs. 31.2 (95% CL 28.2 to 34.4) years, P=0.04), had a lower mean reticulocyte count (119 x109/L (95% CL 76-162) vs. 203 (95% CL 129-278), P=0.05), and a higher mean MCV (104.4 fL (95% CL 100.2-108.7) vs. 92.5 (95% CL 87.2-97.8), P=0.0007), compared to those in the highest quartile for ANC (>5.7 x109/L, N=34), but did not otherwise differ (including mean HbF, which was not measured in a standardized way). In older adults with SCD (Table 2), fewer people with SCA than with variant disease were >54 years old, (26/387 HbSS, 7%, vs. 34/183, 19%, respectively). The older adult with SCA had a depressed reticulocyte count and a trend towards a higher creatinine. 45% of adults with SCA were on HU, and only a minority were at MTD, highlighting the challenges to optimal long-term therapy in chronic illness. Those patients not stably on DMT had laboratory evidence for worse anemia and hemolysis, without an evident increase in hospital admissions, perhaps due to a hyper hemolytic phenotype. Despite a more intensive regimen, SCA patients on transfusions had a higher Hgb but did not have hemolysis labs that differed from SCA patients on HU. Further, there was no difference in hospitalizations amongst treatments for SCA, although a decrease in hospitalizations was detectable in variant disease (Table 1). Successful use of DMTs in SCA was challenging even in academic centers, and there was evidence for ongoing hemolysis in treated and untreated patients. These real world data provide useful information about adults (>17 years) with SCD. These data highlight opportunities to improve adherence to therapy (patient-centered) and to prescribing guidelines (provider-centered), and to consider less-burdensome alternatives. Importantly, we found that a large proportion of people with SCA were not on DMT, and with HU often not at MTD. In future, the GRNDaD registry will enable prospective longitudinal real-world analyses of the impact of DMTs and/or newer therapies on clinical outcomes, will enhance quality improvement, and will allow us to more fully explore clinical characteristics, of SCA and variant disease, in the aging adult. Disclosures Puri-Sharma: Bluebird Bio: Current Employment. Chawla:Bluebird Bio: Current Employment. Field:Shires: Research Funding; Ironwood: Research Funding. Neumayr:Emmaus: Consultancy; Bayer: Consultancy; CTD Holdings: Consultancy; Pfizer: Consultancy; ApoPharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Micelle: Other: Site principal investigator; GBT: Other: Site principal investigator; PCORI: Other: site principal investigator; Novartis: Other: co-investigator; Bluebird Bio: Other: co-investigator; Sangamo Therapeutics: Other; Silarus: Other; Celgene: Other; La Jolla Pharmaceuticals: Other; Forma: Other; Imara: Other; National Heart, Lung, and Blood Institute: Other; Health Resources and Services Administration: Other; Centers for Disease Control and Prevention: Other; Seattle Children's Research: Other. Desai:Pfizer, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; GBT, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Ironwood Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees; Rockpointe Continuing Medical Education Company: Consultancy. Lanzkron:GBT: Research Funding; HRSA: Research Funding; Ironwood: Research Funding; NHLBI: Research Funding; PCORI: Research Funding; Pfizer: Research Funding; Pharmacy Times Continuing Education: Honoraria; Prolong: Research Funding. Little:Hemex Health, Inc.: Patents & Royalties: Microfluidic electropheresis (patent, no royalties); BioChip Labs: Patents & Royalties: SCD Biochip (patent, no royalties); GBT: Research Funding; GBT: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Research Funding; NHLBI: Research Funding.

Oral and laryngeal cutaneous T-cell lymphoma (CTCL) is rare and usually associated with poor prognosis. Here, we discuss 2 cases of oral CTCL that developed in heavily pretreated patients and provide a review of the literature. The first case is of a 46-year-old African American male with rapidly progressive disease, presenting with a lesion on his hard palate 6 months after being diagnosed with a CD4+CD8+ CTCL. His cutaneous disease was widespread with tumors on >80% of his body surface area. Unfortunately, the patient died 2 ½ years after his CTCL diagnosis and 7 months after developing the oral CTCL lesion. The second case is of a 38-year-old African American male with stage IIb CD3+CD4+CD30+ mycosis fungoides (MF), who developed a tumor on the hard palate 6 months after diagnosis. He received palliative radiation to the oral lesion and multiple lines of systemic therapy for pulmonary, laryngeal, esophageal, and gastric involvement. Biopsy of the gastric lesions showed a CD30+ T-cell lymphoma with the same clonal peak as in his skin but with large cell transformation. Brentuximab vendoin was started, and the patient is now in complete remission, 30 months later. From the 76 cases of oral CTCL that have been reported in the English language, six were of transformed MF. The most common sites affected were the tongue and palate, and the most common presentation were erythematous or ulcerated tumors, plaques, or nodules associated with dysphagia and pain. Oral CTCL typically occurs years after the initial diagnosis of CTCL and portend a poor prognosis with an average survival of just over 1 year after development of oral lesions.

Red Blood Cell Adhesion in Adult Patients with Sickle Cell Disease, at Baseline and with Pain, Measured on SCD Biochip Microfluidic Assay Alexandra Boye-Doe1, Erina Quinn1, Charlotte Yuan1, Umut A. Gurkan, PhD1, and Jane A. Little, MD2 1Case Western Reserve University, Cleveland, OH; 2Division of Hematology/Oncology, Case Western Reserve University/ University Hospitals Seidman Cancer Center, Cleveland, OH Background: Despite being monogenic, sickle cell disease (SCD) has a variable phenotype, in which clinical complications and manifestations evolve as patients age. In children, pain generally resolves between crises, whereas adults may experience acute, chronic, or acute-on-chronic pain. We have taken a multifaceted approach to characterize adhesion and inflammation during self-identified pain episodes in adults with SCD in order to better understand pain syndromes in adults and the potential for more specifically targeted therapies. In this pilot study, we assessed changes in red blood cell (RBC) adhesion to the subendothelial protein laminin (LN) during crisis in adults with SCD self-reporting for pain crisis on whom we had baseline adhesion data from a routine clinic visit. Methods: Surplus blood from patients' routine bloodwork was used. Crisis samples were collected from patients at the Acute Care Clinic or Emergency Department at University Hospitals Cleveland Medical Center (UHCMC) when patients presented for management of pain. Baseline samples were collected during routine visits to the Sickle Cell Clinic. This study was approved by the IRB at UHCMC. Within a 24-hour period, RBC adhesion to LN was quantitated by microscopy after passage of unprocessed whole blood through a LN-coated microfluidic adhesion assay, the SCD biochip [1]. Samples were analyzed for hemoglobin (Hb) phenotype by high-performance liquid chromatography (HPLC) in the clinical lab. Correlative clinical data, including, baseline lab values, and medical history, were obtained from the patients' medical records and used to characterize our results. Data from people with multiple samples were used as median values. Results: Blood samples from 19 unselected patients with sickle cell hemoglobin SS (HbSS) were obtained at crisis, and compared with baseline samples obtained from 2014 to 2018 (n = 67 samples). 2 groups were identified: Group 1 with increased adhesion (>25% rise from baseline, n= 10) during crisis, and Group 2 with decreased adhesion (>25% fall from baseline, n=8) or no change (<25% change) (n=1) during crisis (Fig. 1). Time between a patient's initial crisis event and when they presented for pain management varied, possibly affecting observed adhesion. Nonetheless, patients showing an increased adhesion in crisis also showed a decrease in Hb (p = 0.039) between their baseline analyses and the crisis visit. A decrease in Hb may associate with increased adhesion, if the latter contributes to crisis-related hemolysis. However, other markers of hemolysis did not change. By contrast, patients with decreasing RBC adhesion showed a decrease in absolute reticulocyte count (ARC, p = 0.019) at their crisis visit. Statistical analysis of HbS, HbA, and HbF levels n = 64 showed no significant change between baseline or crises. Discussion: A decrease in adhesion during crisis may reflect the presence of sickled RBCs that adhere preferentially to other basement membrane proteins such as fibronectin or thrombospondin. In addition, inflammatory white blood cell adhesion, possibly central to vaso-occlusion, is not evaluated in this study. We are currently examining cytokine and monocyte profiles from people with SCD presenting for management of pain, so that we may better understand inflammatory mediators of pain. Our data are the first to try to understand RBC adhesion in people with SCD who present for management of pain, whether this as an isolated or common event for that person. We found that unselected adults with SCD who presented for management of pain had heterogeneous changes in RBC adhesion, which may reflect differences in underlying mechanism. The pathophysiologic heterogeneity of pain in adults with SCD will be important to understand as anti-adhesion therapies are being developed and adopted clinically. Disclosures Little: Doris Duke Charitable Foundations: Research Funding; NHLBI: Research Funding; Hemex: Patents & Royalties: Patent, no honoraria; PCORI: Research Funding.