Abstract: Paravertebral extramedullary hematopoietic masses (EHMs) account for up to 15% of extramedullary pseudotumors in beta‐thalassemia (BT) and are most likely related to compensatory hematopoiesis. In most cases, pseudotumors are incidentally detected, as the majority of patients are asymptomatic. Since June 2020, luspatercept is approved for the treatment of patients with BT who require regular red blood cell transfusions. Data addressing the safety and efficacy of luspatercept in patients with BT‐associated EHMs are pending. To date (May 2022), paravertebral EHMs were observed in two asymptomatic patients out of currently 43 adult patients with BT registered at the Adult Hemoglobinopathy Outpatient Unit of the University Hospital Essen, Germany. In one of them, a paravertebral EHM was diagnosed more than 10 years prior to referral. Throughout observation time, treatment with luspatercept was associated with a clinically significant reduction in transfusion burden while allowing to maintain a baseline hemoglobin concentration of ≥10 g/dL aiming to suppress endogenous (ineffective) erythropoiesis associated with BT. Considering the rarity of paravertebral EHMs in BT, luspatercept might potentially represent a novel therapeutic option for these often‐serious disease‐associated complications. However, appropriate follow‐up investigations are recommended to detect (early) treatment failures secondary to an undesired luspatercept‐associated erythroid expansion.

Abstract: Introduction: Telomere biology disorders (TBD) are caused by mutations affecting proper telomere maintenance resulting in premature telomere shortening. Telomere length (TL) assessment is currently being used for screening and diagnosis of TBD of which Dyskeratosis congenita (DKC) is the most prominent TBD subtype typically found in children and adolescents. In adults, TBDs are characterized by a broad spectrum of more "cryptic" diverging mono- or oligosymptomatic clinical manifestations such as bone marrow failure (BMF), hepatopathy or interstitial lung disease (ILD). However, despite growing general clinical awareness and exertion of improved TL screening strategies, insufficient data are available about the clinical course of adult, late-onset TBDs. Here, we present a series of 41 consecutive adult TBD cases from 2014 to 2021 identified through the Aachen Telomeropathy registry. Methods and Patients: Median follow-up of the cohort was 2.0 (range 0-6.2) years. In 39/41 patients TBD diagnosis was established based on coexistence of the following three criteria: 1.) Identification of pathogenic variant in a known TBD-related gene via next-generation panel sequencing (NGS) or sequential whole exome sequencing (WES). 2.) The presence of prematurely shortened TL below the 1% percentile (39/41) or 5% percentile (2/41) in the lymphocyte gate detected by flow-FISH and 3.) the presence of BMF or ILD as predominant clinical manifestation. In 2 out of 41 cases, WES did not identify a definitive pathogenic variant. Here, diagnosis of TBD was established due to short telomere below the 1% percentile, BMF and the presence of typical DKC stigmata, other TBD symptoms and a positive family history. Results: Mean age of our cohort was 35.9 ± 17.6 years. 49% (n=20) of patients were females. Results of the genetic screening revealed heterozygous pathogenic variants in TERC (n=14) and TERT (n=11) as the most frequent variants, followed by RTEL1 (n=6), TIN2 (n=1), CTC1 (n=1) and DKC1 (n=1). Homozygous or compound heterozygous pathogenic variants were found for CTC1 (n=2), NHP2 (n=2) or TCAB1 (n=1). 46% (n=19) of patients had a positive family history. BMF was the most frequent symptom with 93% (n=38) presenting with leukopenia, 78% (n=32) with anemia and 76% (n=31) with thrombocytopenia. ILD was suspected/confirmed clinically in 44% (n=18), hepatopathies in 29% (n=12) and cancer in 12% of the patients in past medical history (n=5, liposarcoma, breast cancer, Hodgkin lymphoma, diffuse large B-cell lymphoma, endometrial cancer). Symptoms of the typical DKC triad (leukoplakia, nail dystrophy, abnormal skin pigmentation) were observed in 41% (n=17). Of those, 76% (13/17) presented with only one or two clinical signs. Based on past medical history, the onset of first TBD manifestation was observed at a mean age of 26.9 ± 18.3 years. Time from first symptom observed to the diagnosis of TBD was 8.2 ± 9.5 years. 22% (n=9) patients died during follow-up with mean time of 11.7 ± 10.1 years from first manifestation of TBD to death. Regarding treatment, 39% (n=16) were listed for allogeneic stem cell transplantation (allo Tx), but only 38% (6/16) of these eventually received allo Tx. Immunosuppressive therapy with ATG and CSA was carried out in 12% (n=5) of the patients with no patient responding to treatment. Eltrombopag was given in 5% of cases (n=2) without response. 15% (n=6) received androgen treatment with danazol as the most frequently used drug in five of the six reported cases. All patients showed a response at least in one hematological lineage. Conclusions: Our data support the notion that despite the recent progress in screening and genetic diagnostics, late-onset TBD is still frequently underdiagnosed with several years from first manifestation of disease to diagnosis. Implementation of routine screening for TBD might improve the rate of correct TBD diagnosis and could help to avoid ineffective treatments. Disclosures Beier: Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz: Other: Travel reembursement; Alexion: Speakers Bureau. Roeth: Novartis: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Kira: Consultancy, Honoraria; Bioverativ, a Sanofi company: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Research Funding; Apellis Pharmaceuticals: Consultancy, Honoraria; Alexion Pharmaceuticals Inc.: Consultancy, Honoraria. Platzbecker: AbbVie: Honoraria; Novartis: Honoraria; Celgene/BMS: Honoraria; Janssen: Honoraria; Takeda: Honoraria; Geron: Honoraria. Radsak: Novartis: Consultancy, Honoraria, Other: e.g. travel support; JAZZ: Other: e.g. travel support; Takeda: Consultancy, Honoraria; Celgene/BMS: Consultancy, Honoraria, Other: e.g. travel support; Daiichi Sankyo: Consultancy, Honoraria, Other: e.g. travel support; Astellas: Other: e.g. travel support; Incyte: Consultancy, Honoraria; Corat: Consultancy, Honoraria; Cogent Biosciences: Consultancy, Honoraria; TEVA: Consultancy, Honoraria; Otsuka: Consultancy, Honoraria; Amgen: Other: e.g. travel support; Abbvie: Other: e.g. travel support. Schafhausen: Blueprint Medicines: Membership on an entity's Board of Directors or advisory committees; Alexion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Swedish Orphan Biovitrum AB: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Corbacioglu: Gentium/Jazz Pharmaceuticals: Consultancy, Honoraria. Heuser: AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria; BergenBio: Research Funding; BMS/Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Daiichi Sankyo: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer Pharma AG: Research Funding; Astellas: Research Funding; Karyopharm: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolremo: Membership on an entity's Board of Directors or advisory committees. Koschmieder: Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Karthos: Other: Travel support; Shire: Honoraria, Other; CTI: Membership on an entity's Board of Directors or advisory committees, Other; Sanofi: Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding; Geron: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support), Research Funding; Alexion: Other: Travel support; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support), Research Funding; Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support); Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Baxalta: Membership on an entity's Board of Directors or advisory committees, Other; Abbvie: Other: Travel support; Image Biosciences: Other: Travel support; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding; AOP Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: (e.g. travel support), Research Funding. Panse: Blueprint Medicines: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Chugai: Speakers Bureau; Pfizer: Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Boehringer Ingelheim: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Alexion: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Grunenthal: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Apellis Pharmaceuticals: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Isfort: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel reimbursement; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel reimbursement; Ariad: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria; Hexal: Other: Travel reimbursement; Mundipharma: Other: Travel reimbursement; Amgen: Other: Travel reimbursement; Roche: Other: Travel reimbursement; Alexion: Other: Travel reimbursement. Brummendorf: Bristol Myers: Research Funding; Janssen: Honoraria; Novartis: Honoraria, Patents & Royalties, Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Repeat Diagnostics: Research Funding; Takepart Media: Honoraria.

Abstract: The COVID-19 Community Research Partnership (CCRP) is a multisite surveillance platform designed to characterize the epidemiology of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-COV-2) pandemic. This article describes the CCRP study design and methodology. The CCRP includes two prospective cohorts, one with six health systems in the mid-Atlantic and southern USA, and the other with six health systems in North Carolina. With enrollment beginning in April 2020, sites invited persons within their healthcare systems as well as community members to participate in daily surveillance for symptoms of COVID-like illnesses, testing, and risk behaviors. Participants with electronic health records (EHRs) were also asked to volunteer data access. Subsets of participants, representative of the general population and including oversampling of populations of interest, were selected for repeated at-home serology testing. By October 2021, 65 739 participants (62 261 adult and 3478 pediatric) were enrolled, with 89% providing syndromic data, 74% providing EHR data, and 70% participating in one of the two serology sub-studies. An average of 62% of the participants completed a daily survey at least once a week, and 55% of the serology kits were returned. The CCRP provides rich regional epidemiologic data and the opportunity to more fully characterize the risks and sequelae of SARS-CoV-2 infection.

Abstract: Background: This monocentric study conducted at the University Hospital of Essen aims to describe maternal and fetal/neonatal outcomes in sickle cell disease (SCD) documented between 1996 to 2021 (N = 53), reflecting the largest monocentric analysis carried out in Germany. Methods/Results: 46 pregnancies in 22 patients were followed. None of the patients died. In total, 35% (11/31) of pregnancies were preterm. 15 pregnancies in eight patients were conceived on hydroxycarbamide (HC), of which nine had a successful outcome and three were terminated prematurely. There was no difference regarding the rate of spontaneous abortions in patients receiving HC compared to HC-naive patients prior to conception. In patients other than HbS/C disease, pregnancies were complicated by vaso-occlusive crises (VOCs)/acute pain crises (APCs) (96%, 23/24); acute chest syndrome (ACS) (13%, 3/24), transfusion demand (79%, 19/24), urinary tract infections (UTIs) (42%, 10/24) and thromboembolic events (8%, 2/24). In HbS/C patients complications included: VOCs/APCs (43%, 3/7; ACS: 14%, 1/7), transfusion demand (14%, 1/7), and UTIs (14%, 1/7). Independent of preterm deliveries, a significant difference with respect to neonatal growth in favor of neonates from HbS/C mothers was observed. Conclusion: Our data support the results of previous studies, highlighting the high rate of maternal and fetal/neonatal complications in pregnant SCD patients.

Abstract: Obesity and diabetes are established risk factors for severe SARS-CoV-2 outcomes, but less is known about their impact on susceptibility to COVID-19 infection and general symptom severity. Objective We hypothesized that those with obesity or diabetes would be more likely to self-report a positive SARS-CoV-2 test, and, among those with a positive test, have greater symptom severity and duration. Methods Among 44 430 COVID-19 Community Research Partnership participants, we evaluated the association of self-reported and electronic health record obesity and diabetes with a self-reported positive COVID-19 test at any time. Among the 2663 participants with a self-reported positive COVID-19 test during the study, we evaluated the association of obesity and diabetes with self-report of symptom severity, duration, and hospitalization. Logistic regression models were adjusted for age, sex, race/ethnicity, socioeconomic status, and health care worker status. Results We found a positive graded association between body mass index (BMI) category and positive COVID-19 test (overweight odds ratio [OR] 1.14 [1.05-1.25] ; obesity I OR 1.29 [1.17-2.42]; obesity II OR 1.34 [1.19-1.50] ; obesity III OR 1.53 [1.35-1.73]), and a similar but weaker association with COVID-19 symptoms and severity among those with a positive test. Diabetes was associated with COVID-19 infection but not symptoms after adjustment, with some evidence of an interaction between obesity and diabetes. Conclusion While the limitations of this health system convenience sample include generalizability and selection around test seeking, the strong graded association of BMI and diabetes with self-reported COVID-19 infection suggests that obesity and diabetes may play a role in risk for symptomatic SARS-CoV-2 beyond co-occurrence with socioeconomic factors.

Abstract: Background: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare and life-threatening hematologic disorder leading to hemolytic anemia, which can occur concomitantly with bone marrow disorders (BMD), such as aplastic anemia (AA) and myelodysplastic syndrome (MDS). Accordingly, patients with PNH often require red blood cell (RBC) transfusions to treat anemia due to hemolysis or bone marrow failure. After demonstrating a non-inferior efficacy and safety profile in two of the largest clinical trials to date, ravulizumab was approved as a treatment for adults with PNH, including patients with an underlying history of bone marrow disease, who are transfusion dependent or independent. Aims: To assess the efficacy of ravulizumab in patients with PNH with or without an underlying pathology of AA or MDS, and to investigate the impact of ravulizumab on transfusion burden as measured by number of transfusions and total packed RBC (pRBC) units transfused over a 52-week period. Methods: This phase 3 multicenter, randomized, active-controlled, open-label study (study 301, NCT02946463) enrolled complement-inhibitor-naïve patients with PNH. Patients were aged ≥ 18 years with a confirmed diagnosis of PNH by flow cytometry and lactate dehydrogenase (LDH) level ≥ 1.5x the upper limit of normal (ULN; 246 U/L). Patients received either ravulizumab or eculizumab for 26 weeks; after which all patients received ravulizumab from week 26 to week 52. Efficacy outcomes included the proportion of patients achieving transfusion avoidance (TA), number of pRBC units transfused and the number of pRBC or whole blood transfusions (WBT) received from baseline to 26 and 52 weeks of treatment. In this retrospective analysis, outcomes were analysed for the following subgroups: AA, MDS or no BMD (medical history of AA or MDS was determined by the investigator at screening). Descriptive statistics were calculated for continuous (means) and categorical variables (numbers and percentages). Formal hypothesis testing for significance between treatment groups was not performed. Results: Of the 246 patients included in the study, 79 had a history of AA (32.1%) and 13 (5.3%) had a history of MDS. Baseline characteristics were comparable between treatment groups. From baseline to week 26, a comparable proportion of patients with AA achieved TA to those with no BMD; 75.6% for patients with AA and no BMD receiving ravulizumab, and 60.5% and 73.7% for patients with AA and no BMD receiving eculizumab, respectively (Table 1). Importantly, TA was maintained through 52 weeks, with similar proportions of patients with AA (87.1‒91.3%) maintaining TA to patients without BMD (85.7‒91.5%). More specifically, 65.9% of patients with AA and 69.2% of patients without BMD achieved TA through 52 weeks of ravulizumab treatment, and 55.3% and 63.2% of patients with AA and without BMD, respectively, achieved TA on eculizumab followed by ravulizumab. The proportion of patients with MDS who achieved TA appeared numerically lower compared with patients with AA or no BMD, however, this subgroup sample size was small. Furthermore, a lower proportion of patients on ravulizumab with AA or MDS received any transfusion from baseline to weeks 26 and 52 compared with those treated with eculizumab followed by ravulizumab: for week 26, 24.4% and 57.1% for ravulizumab versus 39.5% and 100.0% for eculizumab in patients with AA and MDS, respectively, and for week 52, 29.3% and 57.1% for patients with AA and MDS receiving ravulizumab for 52 weeks versus 44.7% and 100.0% for patients with AA and MDS treated with eculizumab followed by ravulizumab. In addition, ravulizumab-treated patients with AA or MDS had numerally fewer transfusions and units of pRBC/WBT compared with those who received eculizumab followed by ravulizumab. Overall, the exploratory nature of the analysis and small sample size means that interpretation of the data is limited. Conclusions: This analysis demonstrates that majority of patients with PNH and AA who received ravulizumab avoided the need for transfusion up to 52 weeks of treatment. Patients treated with ravulizumab for the 52-week period had numerically fewer transfusions and units of pRBC/WBT transfused compared with patients who received eculizumab followed by ravulizumab. Overall, these findings support the use of ravulizumab in complement-inhibitor-naïve patients with PNH, with or without a history of BMD. Disclosures Risitano: Amyndas: Consultancy; Samsung: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Jazz: Speakers Bureau; RA pharma: Research Funding; Pfizer: Speakers Bureau; Apellis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Biocryst: Membership on an entity's Board of Directors or advisory committees; Alexion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Alnylam: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Achillion: Membership on an entity's Board of Directors or advisory committees. Schrezenmeier:Alexion Pharmaceuticals Inc.: Honoraria, Research Funding. Yonemura:Alexion Pharmaceuticals: Honoraria, Research Funding. Munir:Alexion: Honoraria; F. Hoffmann-La Roche: Consultancy, Other: Medical writing support, furnished by Scott Battle, PhD, of Health Interactions, was funded by F. Hoffmann-La Roche Ltd, Basel, Switzerland. Pavani:Alexion Pharmaceuticals: Current Employment. Wang:Alexion Pharmaceuticals Inc.: Current Employment. Kulagin:Alexion Pharmaceuticals Inc.: Consultancy, Research Funding. Kulasekararaj:Alexion Pharmaceuticals Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees. Sicre de Fontbrune:Alexion Pharmaceuticals Inc.: Honoraria, Research Funding. Röth:Novartis: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria; Biocryst: Consultancy, Honoraria; Apellis: Consultancy, Honoraria; Alexion Pharmaceuticals Inc.: Consultancy, Honoraria, Research Funding.

Abstract: Prevention behaviors represent important public health tools to limit spread of SARS-CoV-2. Adherence with recommended public health prevention behaviors among 20000 + members of a COVID-19 syndromic surveillance cohort from the mid-Atlantic and southeastern United States was assessed via electronic survey following the 2020 Thanksgiving and winter holiday (WH) seasons. Respondents were predominantly non-Hispanic Whites (90%), female (60%), and ≥ 50 years old (59%). Non-household members (NHM) were present at 47.1% of Thanksgiving gatherings and 69.3% of WH gatherings. Women were more likely than men to gather with NHM (p  〈  0.0001). Attending gatherings with NHM decreased with older age (Thanksgiving: 60.0% of participants aged  〈  30 years to 36.3% aged ≥ 70 years [p-trend  〈  0.0001]; WH: 81.6% of those  〈  30 years to 61.0% of those ≥ 70 years [p-trend  〈  0.0001]). Non-Hispanic Whites were more likely to gather with NHM than were Hispanics or non-Hispanic Blacks (p  〈  0.0001). Mask wearing, reported by 37.3% at Thanksgiving and 41.9% during the WH, was more common among older participants, non-Hispanic Blacks, and Hispanics when gatherings included NHM. In this survey, most people did not fully adhere to recommended public health safety behaviors when attending holiday gatherings. It remains unknown to what extent failure to observe these recommendations may have contributed to the COVID-19 surges observed following Thanksgiving and the winter holidays in the United States.

Abstract: BACKGROUND: In contrast to other B-cell neoplasias, chronic lymphocytic leukemia (CLL) is not only characterized by a clonal expansion of specific B-cells, but also by an increase in non-leukemic T-cells, most likely involved in sustaining the growth of the leukemic B-cell clone. Based on ZAP-70, CD38 and the IgVH mutation status, two prognostic groups of CLL patients can be identified. Our aim was to characterize the replicative histories of the B- and T-cells in the two groups of CLL patients compared to healthy individuals. PATIENTS and METHODS: Blood samples from 73 patients with CLL (ZAP-70−/CD38−: n = 29, ZAP-70+/CD38+: n = 30, ZAP-70/CD38 discordant: n = 14) were analyzed. The quantity and characteristics of the lymphocyte subsets was assessed by a cell counter and by immunophenotypic analysis. The replicative histories of naive and memory T-cells as well as B-cells was determined by measurements of telomere length in peripheral blood leukocytes of CLL patients and healthy individuals by automated multicolor flow-FISH. RESULTS: As expected, the average telomere length of the clonal B-cells was short. The telomere length was, however, significantly shorter for the ZAP-70+/CD38+ patient samples (2.46 ± 1.08 kb) than for the ZAP-70−/CD38− patient samples (5.06 ± 1.76 kb, p 〈 6.7 x 10−9). Interestingly, also the naive and memory T-cells from ZAP-70+/CD38+ CLL patients exhibited significantly shorter average telomere lengths (mean ± std: 4.85 ± 1.58 kb; 4.39 ± 1.09 kb) than T-cells from ZAP-70−/CD38− CLL patients (6.64 ± 1.72 kb, p 〈 2.2 x 10−4; 6.22 ± 1.5 kb, p 〈 7.4 x 10−6). These results are in line with the observed higher absolute T-cell numbers in the ZAP-70+/CD38+ CLL patients compared to ZAP-70−/CD38− CLL patients. Moreover, the average telomere loss in relation to time from primary diagnosis to sample date was higher for naive T-cells than memory T-cells in ZAP-70+/CD38+ patients (7.8 vs. 5.8 bp/month). When we compared the telomere length to age-related percentiles calculated from over 400 healthy individuals aged 0–102 years practically all telomere length values of the naive and memory T-cells from the ZAP-70+/CD38+ CLL patients fell below the 50th percentile, whereas the values of naive and memory T-cells from the ZAP-70−/CD38− CLL patients were within the normal distribution. CONCLUSIONS: We can confirm significantly shorter telomere length values for the B-cells of the ZAP-70+/CD38+ CLL patients. In addition, we can also demonstrate significantly shorter telomeres in T-cells of ZAP-70+/CD38+ CLL patients, which are below the 50th percentile compared to controls, and a higher telomere loss over time for naive T-cells of ZAP-70+/CD38+ CLL patients. As telomere length shortens approximately 50 to 100 bp per cell division the observed decrease in telomere length of the T-cells in ZAP-70+/CD38+ CLL patients equals to approximately 18 to 36 population doublings. This is by far more than expected by the slightly higher T-cell numbers in the peripheral blood. Our observations imply an extensive expansion of the T-cell compartment in ZAP-70+/CD38+ CLL patients and suggest an important role of T-cells in this subgroup of CLL patients.

Abstract: BACKGROUND: Paroxysmal nocturnal hemoglobinuria (PNH) is caused by an acquired mutation in the phosphatidylinositol (GPI)-anchors. The lack of GPI-anchored proteins on the surface of affected red blood cells (RBCs) results in complement mediated chronic intravascular hemolysis. The monoclonal anti-C5 antibody eculizumab protects PNH RBCs by blocking the terminal complement cascade. Eculizumab treated PNH patients show a dramatic decrease of LDH and bilirubin, however few patients remain hyperbilirubinemic, eventually indicating an inadequate response. Hepatocanalicular transporters are rate-limiting in the process of bile formation, and mutations in the genes encoding these transporters cause intrahepatic cholestasis. PATIENTS and METHODS: Mutation analysis regarding hepatobiliary transporter and nuclear receptor defects (ABCB4, ABCB11, ATP8B1, NR1H4) were performed in eight [75% (6/8) male; mean age, 40 years (range 25 - 70 years)] out of the currently 141 patients with PNH/-clone at our department due to a persistent (isolated) increase in total serum bilirubin (median 4.5 mg/dL; range 3.0 - 8.5) during chronic treatment with eculizumab (LDH: median 274 U/L; range 172 - 836) and normal or slightly increased aminotransferases. Clinical symptoms resembled those of hyperbilirubinemia including jaundice. Median clone size of GPI-deficient granulocytes (FLAER) was 98.1% (range 79.0 - 99.5%), with a median observation time of 56.4 months (range 10.6 - 82.7 months). All patients were treated according to the current German PNH guidelines. RESULTS: Both homozygous and heterozygous procholestatic variants in the ABCB4, ABCB11 and ATP8B1 genes, encoding canalicular transporters, were identified in the studied patients, and all patients carried the common ABCB4 c.787 A 〉 T polymorphism (Table 1). None of the patients were tested positive for the common mutation c.-1g 〉 t of the central bile acid sensor NR1H4. Table 1. Hepatobiliary transporter gene variants in PNH patients (n=8) Variant Pat. 1 Pat. 2 Pat. 3 Pat. 4 Pat. 5 Pat. 6 Pat. 7 Pat. 8 ABCB4 c.504T 〉 C (rs1202283) HOM HET HET HOM neg. neg. HOM neg. ABCB4 c.787A 〉 T (rs2109505) HOM HOM HOM HOM HOM HOM HOM HET ABCB11 p.A444V (rs2287622) HOM HET neg. HET neg. neg. HET HOM ABCB11 c.3084A 〉 G (rs497692) HET HET HET neg. HOM HET HOM HET ATP8B1 p.R952Q (rs12968116) HOM neg. HET HET neg. HET neg. neg. NR1H4 (FXR) c.-1 g 〉 t (rs56163822) neg. neg. neg. neg. neg. neg. neg. neg. Pat.: Patient; HOM: homozygous; HET: heterozygous; neg.: negative Routine sonographic follow-up examinations were performed in 75% of the patients (6/8) ruling out post-hepatic cholestasis. In three patients (pat. 2, 3 and 4), a cholecystectomy due to symptomatic cholelithiasis had been performed prior to diagnosis of PNH, whereas in one patient the diagnosis of a persistent, asymptomatic cholelithiasis (pat. 6) was made. A chronic (active) or recently acquired viral hepatitis was ruled out in all patients. Lab parameters were consistent with an isolated persistent increase in total serum bilirubin, despite normal (7/8) or slightly elevated transaminases (1/8; pat. 6) throughout observation time. SUMMARY/CONCLUSIONS: This is the first report of mutations in hepatobiliary transporter genes predisposing to intrahepatic cholestasis in PNH patients. Therefore, persisting hyperbilirubinemia in PNH patients chronically treated with eculizumab might not be due to an insufficient response to eculizumab but due to bile acid transporter variants and ongoing extravascular hemolysis. Patients should be tested for and possible therapeutic agents established in the management include ursodeoxycholic acid, promoting bile flow, and rifampicin, accelerating hepatic detoxification and excretion of bilirubin and bile acids. Our data warrant further studies concerning the role of hepatobiliary transporter variants in PNH patients in order to determine their clinical significance. Disclosures Dührsen: Roche: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Alexion Pharmaceuticals: Honoraria, Research Funding. Röth:Geron: Research Funding; Alexion Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.