Combinatorial targeting of epigenome-modifying enzymes with decitabine and RN-1 synergistically increases HbF

Increased fetal hemoglobin (HbF) levels reduce the symptoms of sickle cell disease (SCD) and increase the lifespan of patients. Because curative strategies for bone marrow transplantation and gene therapy technologies remain unavailable to a large number of patients, the development of a safe and effective pharmacological therapy that increases HbF offers the greatest potential for disease intervention. Although hydroxyurea increases HbF, a substantial proportion of patients fail to demonstrate an adequate response. Pharmacological inhibitors of DNA methyltransferase (DNMT1) and lysine-specific demethylase 1A (LSD1), 2 epigenome-modifying enzymes associated with the multiprotein corepressor complex recruited to the repressed γ-globin gene, are powerful in vivo inducers of HbF. The hematological side effects of these inhibitors limit feasible clinical exposures. We evaluated whether administering these drugs in combination could reduce the dose and/or time of exposure to any single agent to minimize adverse effects, while achieving additive or synergistic increases in HbF. The DNMT1 inhibitor decitabine (0.5 mg/kg per day) and the LSD1 inhibitor RN-1 (0.25 mg/kg per day) administered in combination 2 days per week produced synergistic increases in F-cells, F-reticulocytes, and γ-globin messenger RNA in healthy baboons. Large increases in HbF and F-cells were observed in healthy, nonanemic, and anemic (phlebotomized) baboons. Combinatorial therapy targeting epigenome-modifying enzymes could thus be a useful strategy for producing larger increases in HbF to modify the clinical course of SCD.

Oncology distress screening within predominately Black Veterans: Outcomes on supportive care utilization, hospitalizations, and mortality

BACKGROUND

We evaluated whether patients' initial screening symptoms were related to subsequent utilization of supportive care services and hospitalizations, and whether patient-level demographics, symptoms, hospitalizations, and supportive care service utilization were associated with mortality in primarily low-income, older, Black Veterans with cancer.

METHODS

This quality improvement project created collaborative clinics to conduct cancer distress screenings and refer to supportive care services at an urban, VA medical center. All patients completed a distress screen with follow-up screening every 3 months. Supportive care utilization, hospitalization rates, and mortality were abstracted through medical records. Poisson regression models and cox proportional hazard models were utilized.

RESULTS

Five hundred and eighty five screened patients were older (m = 72), mostly Black 70% (n = 412), and had advanced cancer 54%. Fifty-eight percent (n = 340) were screened only once with 81% (n = 470) receiving ≥1 supportive care service and 51.5% (n = 297) being hospitalized ≥1 time 18 months following initial screen. Symptom severity was significantly related to number of hospitalizations. Low mood was significantly related to higher supportive services (p < 0.001), but not hospitalizations (p ≥ 0.52). Pain, fatigue, physical function, nutrition, and physical symptoms were significantly associated with more supportive services and hospitalizations (p < 0.01). Twenty percent (n = 168) died; Veterans who were Black, had lower stage cancers, better physical health, and utilized less supportive care services had lower odds of mortality (p ≤ 0.01).

CONCLUSION

Individuals with elevated distress needs and those reporting lower physical function utilized more supportive care services and had higher hospitalization rates. Lower physical function, greater supportive care use, higher stage cancer, and being non-Black were associated with higher odds of death.

Epigenetic regulation of hemoglobin switching in non-human primates

Human hemoglobin switching describes the highly regulated, sequential expression of the 5 β-like globin genes (HBE, HBG2, HBG1, HBD and HBB) of the human β-globin gene complex. The sequential activation of these β or β-like globin genes during human development from early embryonic through late fetal ('adult') stages, and during erythroid maturation, occurs in an order corresponding to their 5' to 3' location on chromosome 11. The β-hemoglobinopathies are the most common inherited diseases in humanity, and are diseases of mutated HBB or its altered regulation. Since the other β-like globin genes can potentially substitute for defective HBB, much translational research is directed toward understanding and manipulating sequential activation at the human β-globin gene complex to treat β-hemoglobinopathies. Non-human primates provide a vital contribution to such efforts because of their recapitulation of the developmental/maturational switch in hemoglobin production as observed in humans (mice do not model this switch). Valuable insights into druggable epigenetic forces that mediate the switch have been thereby gained. We review important lessons learned in non-human primates, complemented by other studies, and suggest rational next steps.

AVPR1A and Stress in Adults With Sickle Cell Disease–Related Chronic Pain

Purpose: Emotional stress is a known pain trigger in patients with sickle cell disease (SCD). The Arginine vasopressin receptor 1A gene (AVPR1A), SNP rs10877969, is associated with acute pain and stress-related pain. Our study investigated the association between AVPR1A genotype with stress and age in adults with SCD pain. Methods: 169 participants with SCD and chronic pain (100% African descent; mean age 36.4 ± 11.6 years [range =18-74 years]) completed the Perceived Stress Questionnaire. The SNP was evaluated as the imputed score was R2&gt;0.8. ANOVA compared stress by genotype and age. Findings: Mean stress scores were significantly lower (p&lt;0.05) for the older adults (0.35 ± 0.18) than the younger adults (0.41 ± 0.17). Mean stress scores were not significantly different by genotype for younger or older adults. Discussion: The rs10877969 genotype frequency was not different by age. In contrast to prior research, there was no association between genotype and stress.

Early Detection of Acute Chest Syndrome Through Electronic Recording and Analysis of Auscultatory Percussion

Acute chest syndrome (ACS) is the leading cause of death among people with sickle cell disease. ACS is clinically defined and diagnosed by the presence of a new pulmonary infiltrate on chest imaging with accompanying fever and respiratory symptoms like hypoxia, tachypnea, and shortness of breath. However, the characteristic chest x-ray (CXR) findings necessary for a clinical diagnosis of ACS can be difficult to detect, as is determining which patient needs a CXR. This makes early detection difficult; but it is critical in order to limit ACS severity and subsequent fatalities. This research project looks to apply percussion and auscultation techniques that can provide an immediate diagnosis of acute pulmonary conditions by using an automated standard percussive input and electronic auscultation for computational analysis of the measured signal. Measurements on sickle cell patients having ACS, vaso-occlusive crisis (VOC), and regular clinic visits (healthy) were recorded and analyzed. Average intensity of sound transmission through the chest and lungs was determined in the ACS and healthy subject groups, revealing an average of 10–14 dB decrease in sound intensity in the ACS group compared to the healthy group. A random under-sampling boosted tree classification model identified with 94% accuracy the positive ACS and healthy observations. The analysis also revealed unique measurable changes in a small number of cases clinically classified as complicated VOC, which later developed into ACS. This suggests the developed approach may also have early predictive capability, identifying patients at risk for developing ACS prior to current clinical practice.

Meeting the guidelines: Implementing a distress screening intervention for veterans with cancer

BACKGROUND

Guidelines recommend systematic evaluation of distress screening and referral for cancer patients. Implementation remains a notable gap for cancer centers serving disadvantaged communities. We present the implementation of a distress screening program within a Veterans Affairs hospital oncology clinic, serving a majority African American (AA) male population of low socioeconomic status (SES).

METHODS

The Coleman Foundation funded this program supporting a palliative care physician and psychologist to implement screening in a phased approach as follows: (1) Organizing key stakeholders, (2) educating clinical staff, (3) delivering distress screening, (4) generating documentation, and (5) implementing clinical action and referral pathways. We utilized validated measures in the "Patient Screening Questions for Supportive Care" screening tool.

RESULTS

This program was unsuccessful in screening all veterans with cancer; however, we were able to implement 3 years of longitudinal screening. In distress screens from the initial program period (n = 253), patients were primarily males (95.6%) of older age (m = 70, standard deviation = 9.45), AA (76.4%), with various cancers of advanced disease (69%). Males reported moderate psychosocial distress and elevated financial needs. For males with elevated psychosocial distress (n = 63, PHQ-4 ≥3), 36% were previously connected with psychosocial services. Following screening, engagement increased as the majority (77%) established psychosocial care.

CONCLUSIONS

This screening program had mixed success. Centralized program staff and available supportive care referrals were critical for program implementation. Screening may have increased engagement in social work/mental health services for males of low SES. Screening programs should be tailored to the needs of underserved communities with accessible housing/food subsidies.

Selenium Deficiency in a Mouse Model of Sickle Cell Disease Resulted in Increased Oxygen Consumption and Aberrant Mitochondrial Retention (OR11-05-19)

Objectives

Sickle Cell Disease (SCD) is caused by a single point mutation in the β-globin gene, resulting in the polymerization of the altered hemoglobin βS in hypoxic conditions, affecting millions of people worldwide. Previous studies have shown that there are lower selenium levels and reduced activity of the antioxidant selenoprotein GPX1 in SCD patients. The objective of this study was to investigate the consequences of selenium deficiency in a SCD mouse model.

Methods

Humanized SCD (HbSS) mice (Townes model) and wild type (HbAA) mice were purchased from Jackson Laboratories (Bar Harbor, ME). Mice were fed either a selenium-deficient (<0.01 mg/kg) or a selenium adequate (0.1 mg/kg) diet for 4 weeks. Hematological testing was performed using the ADVIATM 120 analyzer (Bayer Corporation, NY). Mitochondrial retention and reactive oxygen species (ROS) were measured by flow cytometry with a BD LSRFortessaTM analyzer using Kaluza analysis software (Beckman Coulter, CA). The oxygen consumption rate (OCR) was measured from isolated red blood cells (RBCs) in real time using the Seahorse Extracellular Analyzer (Agilent, CA).

Results

RBCs normally eject their mitochondria before reaching maturity. However, a previous study demonstrated that there was increased RBC mitochondrial retention in SCD mice and patients when compared to controls. Feeding SCD mice a selenium deficient diet resulted in increased retention of mitochondria in RBCs (26% + 6.9%, 5% + 3.5%, n = 3, P < 0.01), decreased hemoglobin levels (5.7 + 0.17 g/dl, 7.0 + 0.83 g/dl, n = 3, P < 0.05), and an increased OCR of the RBCs (P < 0.01) in these animals when compared to SCD mice fed a selenium adequate diet.

Conclusions

Providing humanized SCD mice a selenium deficient diet resulted in increased mitochondrial retention in mature RBCs, decrease hemoglobin levels, and increased RBC oxygen consumption. RBC retention of mitochondria is associated with increased ROS and hemolysis, potentially contributing to the pain and vaso-occlusive crises that occur in the disease. These studies indicate that selenium deficiency may contribute to the severity of symptoms experienced by patients with SCD.

Funding Sources

This work is supported by a grant from the NIH.

Abstract TP463: Enhancing Access to Stroke Neurology Care for Patients With Sickle Cell Disease

Introduction: Patients with chronic illness have demonstrated non-adherence rates to clinic appointments ranging between 20-40%, however, few studies have documented non-adherence rates in patients with sickle cell disease. One study estimated that during an 8-month period non-adherence rates were as high as 46%. Patients with sickle cell disease and a history of prior stroke are at particularly high risk of recurrence for secondary stroke requiring routine follow up. This study aimed at examining the effect on non-adherence rates after the development of a combined stroke-sickle cell outpatient clinic.

Methods: Non-adherence rates were examined in the separate stroke clinic and compared to the combined outpatient stroke-sickle cell clinic, staffed by a vascular neurology physician, an advanced practice nurse (APN) and a hematology physician. The APN was readily available for consultation and follow-up of patients with a history of stroke, suspected stroke, or transient ischemic attack. Non-adherence rates were calculated based on no show events over total scheduled clinic events. Descriptive statistics were used to compare groups of patients and a Chi-Square was used to compare non adherence between groups.

Results: Since September 2015 to August 2018, there was a total of 34 total scheduled clinic visits in the separate stroke clinic, resulting in a non-adherence rate of 26.5%. Since the inception of the combined stroke-sickle cell clinic in September 2016 to August 2018, there was a total of 45 scheduled clinic visits, resulting in a non-adherence rate of 11.1%. The number of new consultations for the stroke clinic and combined clinic were 44.1% and 40.0% respectively.

Conclusion: The development of a combined stroke-sickle cell outpatient clinic may be an effective, multidisciplinary method for improving non-adherence rates in patients with sickle cell disease and a history of stroke. In addition, creating a combined clinic both increases patient access for both sickle cell patients at high risk for cerebrovascular disease as well as stroke patients without a history of sickle cell disease.

Oral tetrahydrouridine and decitabine for non-cytotoxic epigenetic gene regulation in sickle cell disease: A randomized phase 1 study

BACKGROUND

Sickle cell disease (SCD), a congenital hemolytic anemia that exacts terrible global morbidity and mortality, is driven by polymerization of mutated sickle hemoglobin (HbS) in red blood cells (RBCs). Fetal hemoglobin (HbF) interferes with this polymerization, but HbF is epigenetically silenced from infancy onward by DNA methyltransferase 1 (DNMT1).

METHODS AND FINDINGS

To pharmacologically re-induce HbF by DNMT1 inhibition, this first-in-human clinical trial (NCT01685515) combined 2 small molecules-decitabine to deplete DNMT1 and tetrahydrouridine (THU) to inhibit cytidine deaminase (CDA), the enzyme that otherwise rapidly deaminates/inactivates decitabine, severely limiting its half-life, tissue distribution, and oral bioavailability. Oral decitabine doses, administered after oral THU 10 mg/kg, were escalated from a very low starting level (0.01, 0.02, 0.04, 0.08, or 0.16 mg/kg) to identify minimal doses active in depleting DNMT1 without cytotoxicity. Patients were SCD adults at risk of early death despite standard-of-care, randomized 3:2 to THU-decitabine versus placebo in 5 cohorts of 5 patients treated 2X/week for 8 weeks, with 4 weeks of follow-up. The primary endpoint was ≥ grade 3 non-hematologic toxicity. This endpoint was not triggered, and adverse events (AEs) were not significantly different in THU-decitabine-versus placebo-treated patients. At the decitabine 0.16 mg/kg dose, plasma concentrations peaked at approximately 50 nM (Cmax) and remained elevated for several hours. This dose decreased DNMT1 protein in peripheral blood mononuclear cells by >75% and repetitive element CpG methylation by approximately 10%, and increased HbF by 4%-9% (P < 0.001), doubling fetal hemoglobin-enriched red blood cells (F-cells) up to approximately 80% of total RBCs. Total hemoglobin increased by 1.2-1.9 g/dL (P = 0.01) as reticulocytes simultaneously decreased; that is, better quality and efficiency of HbF-enriched erythropoiesis elevated hemoglobin using fewer reticulocytes. Also indicating better RBC quality, biomarkers of hemolysis, thrombophilia, and inflammation (LDH, bilirubin, D-dimer, C-reactive protein [CRP]) improved. As expected with non-cytotoxic DNMT1-depletion, platelets increased and neutrophils concurrently decreased, but not to an extent requiring treatment holds. As an early phase study, limitations include small patient numbers at each dose level and narrow capacity to evaluate clinical benefits.

CONCLUSION

Administration of oral THU-decitabine to patients with SCD was safe in this study and, by targeting DNMT1, upregulated HbF in RBCs. Further studies should investigate clinical benefits and potential harms not identified to date.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01685515.

Conjunctival microvascular hemodynamics following vaso-occlusive crisis in sickle cell disease

Painful vaso-occlusive crisis (VOC) is the clinical hallmark of sickle cell disease (SCD). Microcirculatory hemodynamic changes following painful VOC may be indicative of future development of VOC events in subjects with SCD. The purpose of the present study was to determine alterations in conjunctival microvascular hemodynamics during non-crisis state in SCD subjects with a history of VOC. Conjunctival microcirculation imaging was performed to measure conjunctival diameter (D) and axial blood velocity (V) in 10 control and 30 SCD subjects. SCD subjects were categorized into two groups based on their history of VOC within a 2-year period before imaging (with or without VOC-H) and also based on whether there was progression in the rate of VOCs during a 2-year period following imaging as compared to before imaging (with or without VOC-P). Conjunctival V was significantly higher in SCD subjects with VOC-H than in both control subjects and SCD subjects without VOC-H (P≤0.03). Conjunctival V was also significantly higher in SCD subjects with VOC-P compared with control subjects and SCD subjects without VOC-P (P≤0.03). Assessment of the conjunctival microcirculation may be useful for understanding hemodynamic changes that lead to VOC events in SCD subjects.

Toward understanding family-related characteristics of young adults with sickle-cell disease or sickle-cell trait in the USA

AIMS AND OBJECTIVES

To describe the family-related characteristics of young adults with sickle-cell disease or sickle-cell trait prior to taking part in a randomised controlled trial on sickle-cell reproductive health education.

BACKGROUND

There is a critical need for educational programmes that target the reproductive needs of young adults with sickle-cell disease or trait. However, little is known about the family-related characteristics (i.e., demographic attributes and reproductive health behaviours) in which these young adults live.

DESIGN

A descriptive cross-sectional analysis.

METHOD

At study enrolment, 234 young adults (mean age = 25·9 years, 65% female) completed the SCKnowIQ questionnaire. Descriptive statistics depict the demographic attributes and reproductive health behaviours of young adults with sickle-cell disease (n = 138) or trait (n = 96). For group comparisons, independent t tests or Fisher's tests were used, as appropriate.

RESULTS

Young adults with sickle-cell trait had significantly higher education, income and health insurance than those with sickle-cell disease. Both groups believed that sickle-cell disease was a severe condition. A majority of young adults with sickle-cell disease (65%) had no children compared to 42% of those with sickle-cell trait. Most young adults (85% sickle-cell disease, 82% sickle-cell trait) were not planning a pregnancy in the next six months, and many used condoms, withdrawal or oral contraceptives.

CONCLUSIONS

Socioeconomic disparities exist between young adults with sickle-cell disease and sickle-cell trait. Future research that advances education about how and when to communicate appropriate genetic risk information to partners and children especially for young adults with sickle-cell trait would be beneficial.

RELEVANCE TO CLINICAL PRACTICE

Awareness of the similarities and differences in the family-related characteristics among young adults with sickle-cell disease or trait can allow for more tailored reproductive education.

Perception of young adults with sickle cell disease or sickle cell trait about participation in the CHOICES randomized controlled trial

AIMS

To gain an in-depth understanding of the perceptions of young adults with sickle cell disease and sickle cell trait about parenthood and participating in the CHOICES randomized controlled trial that used computer-based, educational programmes.

BACKGROUND

In the USA, there is insufficient education to assure that all young adults with sickle cell disease or sickle cell trait understand genetic inheritance risks and reproductive options to make informed reproductive decisions. To address this educational need, we developed a computer-based, multimedia program (CHOICES) and reformatted usual care into a computer-based (e-Book) program. We then conducted a two-year randomized controlled trial that included a qualitative component that would deepen understanding of young adults' perceptions of parenthood and use of computer-based, educational programmes.

DESIGN

A qualitative descriptive approach completed after a randomized controlled trial.

METHODS

Sixty-eight men and women of childbearing age participated in semi-structured interviews at the completion of the randomized controlled trial from 2012-2013. Thematic content analysis guided the qualitative description.

RESULTS/FINDINGS

Three main themes were identified: (1) increasing knowledge and new ways of thinking and behaving; (2) rethinking parenting plans; and (3) appraising the program design and delivery. Most participants reported increased knowledge and rethinking of their parenting plans and were supportive of computer-based learning. Some participants expressed difficulty in determining individual transmission risks.

CONCLUSION

Participants perceived the computer programs as beneficial to their learning. Future development of an Internet-based educational programme is warranted, with emphasis on providing tailored education or memory boosters about individual transmission risks.

Neutrophil AKT2 regulates heterotypic cell-cell interactions during vascular inflammation

Interactions between platelets, leukocytes, and activated endothelial cells are important during microvascular occlusion; however, the regulatory mechanisms of these heterotypic cell-cell interactions remain unclear. Here, using intravital microscopy to evaluate mice lacking specific isoforms of the serine/threonine kinase AKT and bone marrow chimeras, we found that hematopoietic cell-associated AKT2 is important for neutrophil adhesion and crawling and neutrophil-platelet interactions on activated endothelial cells during TNF-α-induced venular inflammation. Studies with an AKT2-specific inhibitor and cells isolated from WT and Akt KO mice revealed that platelet- and neutrophil-associated AKT2 regulates heterotypic neutrophil-platelet aggregation under shear conditions. In particular, neutrophil AKT2 was critical for membrane translocation of αMβ2 integrin, β2-talin1 interaction, and intracellular Ca2+ mobilization. We found that the basal phosphorylation levels of AKT isoforms were markedly increased in neutrophils and platelets isolated from patients with sickle cell disease (SCD), an inherited hematological disorder associated with vascular inflammation and occlusion. AKT2 inhibition reduced heterotypic aggregation of neutrophils and platelets isolated from SCD patients and diminished neutrophil adhesion and neutrophil-platelet aggregation in SCD mice, thereby improving blood flow rates. Our results provide evidence that neutrophil AKT2 regulates αMβ2 integrin function and suggest that AKT2 is important for neutrophil recruitment and neutrophil-platelet interactions under thromboinflammatory conditions such as SCD.

IMPROVE trial: a randomized controlled trial of patient-controlled analgesia for sickle cell painful episodes: rationale, design challenges, initial experience, and recommendations for future studies

BACKGROUND

The hallmark of sickle cell disease (SCD) is pain from a vaso-occlusive crisis. Although ambulatory pain accounts for most days in pain, pain is also the most common cause of hospitalization and is typically treated with parenteral opioids. The evidence base is lacking for most analgesic practice in SCD, particularly for the optimal opioid dosing for patient-controlled analgesia (PCA), in part because of the challenges of the trial design and conduct for this rare disease.

PURPOSE

The purpose of this report is to describe our Network's experiences with protocol development, implementation, and analysis, including overall study design, the value of pain assessments rather than 'crisis' resolution as trial endpoints, and alternative statistical analysis strategies.

METHODS

The Improving Pain Management and Outcomes with Various Strategies (IMPROVE) PCA trial was a multisite inpatient randomized controlled trial comparing two PCA-dosing strategies in adults and children with SCD and acute pain conducted by the SCD Clinical Research Network. The specified primary endpoint was a 25-mm change in a daily average pain intensity using a Visual Analogue Scale, and a number of related pain intensity and pain interference measures were selected as secondary efficacy outcomes. A time-to-event analysis strategy was planned for the primary endpoint.

RESULTS

Of 1116 individuals admitted for pain at 31 participating sites over a 6-month period, 38 were randomized and 4 withdrawn. The trial was closed early due to poor accrual, reflecting a substantial number of challenges encountered during trial implementation.

LIMITATIONS

While some of the design issues were unique to SCD or analgesic studies, many of the trial implementation challenges reflected the increasing complexity of conducting clinical trials in the inpatient setting with multiple care providers and evolving electronic medical record systems, particularly in the context of large urban academic medical centers.

LESSONS LEARNED

Complicated clinical organization of many sites likely slowed study initiation. More extensive involvement of research staff and site principal investigator in the clinical care operations improved site performance. During the subsequent data analysis, alternative statistical approaches were considered, the results of which should inform future efficacy assessments and increase future trial recruitment success by allowing substantial reductions in target sample size.

CONCLUSIONS

A complex randomized analgesic trial was initiated within a multisite disease network seeking to provide an evidence base for clinical care. A number of design considerations were shown to be feasible in this setting, and several pain intensity and pain interference measures were shown to be sensitive to time- and treatment-related improvements. While the premature closure and small sample size precluded definitive conclusions regarding treatment efficacy, this trial furnishes a template for design and implementation considerations that should improve future SCD analgesic trials.

Human bulbar conjunctival hemodynamics in hemoglobin SS and SC disease

The known biophysical variations of hemoglobin (Hb) S and Hb C may result in hemodynamic differences between subjects with SS and SC disease. The purpose of this study was to measure and compare conjunctival hemodynamics between subjects with Hb SS and SC hemoglobinopathies. Image sequences of the conjunctival microcirculation were acquired in 9 healthy control subjects (Hb AA), 24 subjects with SC disease, and 18 subjects with SS disease, using a prototype imaging system. Diameter (D) and blood velocity (V) measurements were obtained in multiple venules of each subject. Data were categorized according to venule caliber by averaging V and D for venules with diameters less than (vessel size 1) or greater than (vessel size 2) 15 µm. V in vessel size 2 was significantly greater than V in vessel size 1 in the AA and SS groups (P ≥ 0.009), but not in the SC group (P = 0.1). V was significantly lower in the SC group as compared to the SS group (P = 0.03). In AA and SS groups, V correlated with D (P ≤ 0.005), but the correlation was not statistically significant in the SC group (P = 0.08). V was inversely correlated with hematocrit in the SS group for large vessels (P = 0.03); however, no significant correlation was found in the SC group (P ≥ 0.2). Quantitative assessment of conjunctival microvascular hemodynamics in SS and SC disease may advance understanding of sickle cell disease pathophysiology and thereby improve therapeutic interventions.

Standard clinical practice underestimates the role and significance of erythropoietin deficiency in sickle cell disease

In sickle cell disease (SCD), vigorous reticulocytosis is required to partially compensate for chronic hemolytic anaemia. Consequently, early renal damage, insufficient to cause azotemia but sufficient to cause erythropoietin deficiency and chronic relative reticulocytopenia (chRR), could have severe clinical consequences. chRR was defined as reticulocytes <250×10(9) /l despite haemoglobin <9 g/dl on ≥ two occasions ≥4 weeks apart. The influence of multiple variables including chRR on time from first clinic visit to death was evaluated in 306 SCD patients. In univariate analyses, fetal haemoglobin, indices of renal damage (serum creatinine, proteinuria), chRR and age, were associated with rate of death. In multivariate analysis, only age and chRR (Hazard ratio 3·6, 95% CI 2·049-6·327, P<0·0001) were significant, underlining that chRR could be an early and important clinical consequence of renal damage. Even in chRR patients with normal serum creatinine levels, low haemoglobin and low reticulocyte counts were associated with low erythropoietin levels. In the general population, evaluation of erythropoietin levels is prompted by the combination of anaemia and abnormal serum creatinine. In SCD patients, this standard approach can miss a substantial risk factor for early death. chRR could be a practical and important criterion for diagnosis of erythropoietin deficiency in SCD.

Changes in the activity of the GPx-1 anti-oxidant selenoenzyme in mononuclear cells following imatinib treatment

Imatinib inhibits the ABL tyrosine kinase and is effective for the treatment of chronic myeloid leukemia (CML). ABL activates GPx-1, an enzyme associated with protection against oxidative DNA damage and disease. Enzyme activity was assessed in sample pairs consisting of mononuclear cells obtained from patients before and after imatinib therapy. Control sample sets obtained from patients not receiving imatinib showed little change in GPx activity over a several month interval. Five of 7 sample sets obtained from imatinib-receiving patients showed changes in GPx activity greater than 30%. One sample decreased 42% while 4 others increased 33-208%. Patients with the largest increase in activity were female and had the lowest baseline levels of GPx activity. Changes in GPx activity may influence the clinical outcome of patients being treated for CML.

Reproductive decisions in people with sickle cell disease or sickle cell trait

In the context of an inherited condition such as sickle cell disease (SCD), it is critical to understand how people with SCD or carriers (sickle cell trait [SCT]) face the challenges of making informed reproductive health decisions. The purpose of this analysis was to examine the beliefs, attitudes, and personal feelings of people with sickle cell disease or sickle cell trait related to making informed reproductive health decisions. Three focus groups were conducted with a total of 15 people who had either SCD or SCT. Five themes were identified: health-related issues in sickle cell disease, testing for sickle cell trait, partner choice, sharing sickle cell status with partners, and reproductive options. These findings enhance understanding of the reproductive experiences in people with SCD and SCT and provide the groundwork for developing an educational intervention focused on making informed decisions about becoming a parent.

Sickle cell disease in the United States: looking back and forward at 100 years of progress in management and survival

The past 100 years since James Herrick's first description of sickle cell disease in the United States have been characterized by the gradual development of management strategies. We review the progress in sickle cell disease management in the United States over the past 100 years, with emphasis on the diverse forces surrounding advances in disease management. Mortality and survival data are presented chronologically, with an attempt to highlight improvements in survival associated with specific advancements for pediatric and adult care. Finally, the future course for sickle cell disease management is explored, given the continued work in advancing the field.

Patient-reported outcomes: descriptors of nociceptive and neuropathic pain and barriers to effective pain management in adult outpatients with sickle cell disease

Despite frequent episodes of severe recurrent pain in sickle cell disease (SCD), sensory pain in outpatient adults with SCD lacks sufficient characterization. Furthermore, pivotal barriers may interfere with these patients' adherence to prescribed analgesic therapies but have not been studied systematically. We describe sensory pain characteristics, barriers, and analgesic use reported by adults with SCD during routine clinic visits. Patients (N = 145; 67% female, 94% African American) completed measures on a pen-tablet computer. Patients reported an average of 3.6 +/- 2.3 pain sites; mean current pain intensity (3.3 +/- 3.2), least (3.0 +/- 2.7) and worst (4.9 +/- 3.5) pain intensity in 24 hours on a 0 to 10 scale, multiple neuropathic (4.5 +/- 3.4, 8.3% selected none) and nociceptive (6.8 +/- 4.0) pain descriptors, and continuous pain pattern (59%). Their mean pain barriers score was 2.2 +/- 0.9, and 33% were dissatisfied with their pain levels. Only 14% reported taking at least 1 adjuvant drug, 82% were taking nonopioids, 85% step 2 opioids, and 65% step 3 opioids. Patients reported using, on average, 4.9 +/- 2.7 analgesics. Their pain barriers scores were similar to or greater than people with cancer. Importantly, their pain may be both nociceptive and neuropathic, contrary to common expectations that SCD pain is only nociceptive. Few patients, however, took drugs effective for neuropathic pain.

Pain, coping and health care utilization in younger and older adults with sickle cell disease

Sickle cell disease is characterized by acute pain crises. Pain, chronic medical problems, utilization and coping were compared in younger vs older patients using questionnaires and medical record review. Groups reported similar pain intensity and medical conditions. The pattern of utilization differed such that older patients attended outpatient clinic, and younger patients went to the Emergency Department. Younger patients were more likely to cope by ignoring pain, or by using heat, cold or massage. Older patients were more likely to pray and hope. We conclude that age plays an important role in the utilization and coping of sickle cell patients.

Neurobiological mechanisms of pain in sickle cell disease

Pain is a frequent complaint of people living with sickle cell disease (SCD); however, the neurobiology of pain in SCD remains poorly understood. Whereas this pain has been thought to be primarily related to visceral and somatic tissue injury subsequent to vaso-occlusion events, emerging evidence from human and animal studies has suggested that a component of SCD pain may be related to neuropathic processes. Significant knowledge has been obtained from studies of molecular and neurobiological mechanisms leading to and maintaining neuropathic pain. Some of the most promising evidence has implicated major roles of protein kinase C and Ca2+/calmodulin-dependent protein kinase II, and their interaction with the N-methyl-D-aspartate receptors and the transient receptor potential vanilloid 1 receptor in the development of neuropathic pain. The latest evidence from our studies suggests that these pathways are important for SCD pain as well. Coupled with emerging animal models of SCD pain, we can now start to elucidate neurobiological mechanisms underlying pain in SCD, which may lead to better understanding and effective therapies.

Effects of 5-aza-2'-deoxycytidine on fetal hemoglobin levels, red cell adhesion, and hematopoietic differentiation in patients with sickle cell disease

Fetal hemoglobin (HbF) decreases polymerization of sickle hemoglobin (HbS) and improves outcomes in sickle cell disease (SSD). Therefore, a therapeutic goal in SSD is pharmacologic reactivation of HbF. Silencing of the gamma-globin (HbF) gene is associated with DNA methylation. The cytosine analog 5-aza-2'-deoxycytidine (decitabine) hypomethylates DNA by inhibiting DNA methyltransferase. We examined if subcutaneous decitabine could increase HbF levels and improve SSD pathophysiology without cytotoxicity. Eight symptomatic SSD patients resistant or intolerant of standard treatment with hydroxyurea received decitabine 0.2 mg/kg subcutaneously 1 to 3 times per week in 2 cycles of 6-week duration. Treatment decreased neutrophils and increased mean HbF (6.5% to 20.4%, P <.0001) and mean total hemoglobin (76 to 96 g/L [7.6 to 9.6 g/dL], P <.001). Features of vaso-occlusive crisis pathophysiology such as red cell adhesion, endothelial damage, and coagulation pathway activity significantly improved. gamma-Globin gene promoter methylation decreased, and platelets and the proportion of megakaryocytes and erythroid cells in the marrow increased without a decrease in marrow cellularity, consistent with a DNA hypomethylating, noncytotoxic mechanism of action. Weekly subcutaneous decitabine produces cumulative increases in HbF and total hemoglobin through a noncytotoxic mechanism of action. Chronic dosing and sustained increases in hemoglobin F and total hemoglobin levels may be possible. Further studies in SSD and thalassemia are indicated.

Maintenance of elevated fetal hemoglobin levels by decitabine during dose interval treatment of sickle cell anemia

We have previously demonstrated that 5-aza-2'-deoxycytidine (decitabine) augments fetal hemoglobin (HbF) levels in patients with sickle cell anemia (SS) who did not respond to hydroxyurea (HU). The present study was designed to determine the effect of repeated decitabine dosing on HbF levels and hematologic toxicity over a 9-month treatment period. Seven patients (5 HU nonresponders) were entered. One patient had alpha-thalassemia sickle cell anemia. Decitabine was administered by intravenous infusion at a starting dose of 0.3 mg/kg per day, 5 days a week for 2 weeks, followed by a 4-week observation period. If the absolute neutrophil count dropped below 1000, the dose was reduced by 0.05 mg/kg per day in the next cycle. A drug dose was obtained for each patient, and it resulted in an elevated HbF without neutropenia (absolute neutrophil count nadir greater than 1500) or evidence of cumulative toxicity. Average HbF and average maximal HbF levels attained during the last 20 weeks of treatment for the 6 SS patients increased to 13.93% +/- 2.75% and 18.35% +/- 4.46%, respectively, from a pretreatment mean of 3.12% +/- 2.75%. Mean and mean maximal hemoglobin (Hb) levels increased from 7.23 +/- 2.35 g/dL to 8.81 +/- 0.42 g/dL and 9.73 +/- 0.53 g/dL, respectively. Individual maximal F-cell number observed during the trial was 69% +/- 10.12%. The absence of cumulative toxicity may allow shorter intervals between drug treatments, which may lead to higher hemoglobin and HbF levels after several treatment cycles and, therefore, to greater clinical improvement.

Effects of hydroxurea, stem cell factor, and erythropoietin in combination on fetal hemoglobin in the baboon

OBJECTIVE

Augmentation of the level of fetal hemoglobin (HbF) is considered therapeutic for patients with sickle cell disease. The objective of this study was to determine the effect of treatment with a combination of erythropoietin (Epo), stem cell factor (SCF), and hydroxyurea (HU) on HbF levels.

MATERIALS AND METHODS

The effect of treatment with a combination of Epo, SCF, and HU on HbF, F-cell numbers, and globin chain synthesis was evaluated in a baboon model.

RESULTS

Treatment with a combination of SCF+Epo resulted in a two-fold increase in HbF, F-cells, and F-reticulocytes compared to Epo alone. The combination of SCF+Epo+HU resulted in an additional two-fold increase in HbF, whereas F-cells and F-reticulocytes increased only 25% compared to the SCF+Epo regimen. Measurement of differential globin chain synthesis indicated that the SCF+Epo+HU treatment also increased the I gamma/V gamma (homologous to human G gamma and A gamma) synthetic ratio toward the fetal ratio.

CONCLUSIONS

HU can effectively augment growth factor-induced HbF synthesis in vivo. Because I gamma/V gamma ratios are unaffected by erythropoietic stress and similar increases in this ratio have only been observed following administration of 5-azacytidine, we suggest that these two agents may share a common mechanism of action involving the recruitment of a similar target cell population to terminal erythroid differentiation.

2-deoxy 5-azacytidine and fetal hemoglobin induction in sickle cell anemia

Augmentation of the fetal hemoglobin (HbF) levels is of therapeutic benefit in patients with sickle cell anemia. Hydroxyurea (HU), by increasing HbF, lowers rates of pain crisis, episodes of acute chest syndrome, and requirements for blood transfusions. For patients with no HbF elevation after HU treatment, augmentation of HbF levels by 5-aza-2'-deoxycytidine (5-aza-CdR, decitabine) could serve as an alternate mode of treatment. Eight adult patients participated in a dose-escalating phase I/II study with 5-aza-CdR at doses ranging from 0.15 to 0.30 mg/kg given 5 days a week for 2 weeks. HbF, F cell, F/F cell, gamma-globin synthesis ratio, complete blood count, and chemistry were measured. The average gamma-globin synthesis relative to non-alpha-globin synthesis prior to therapy was 3.19% +/- 1.43% and increased to 13.66% +/- 4.35% after treatment. HbF increased from 3.55% +/- 2.47% to 13.45% +/- 3.69%. F cells increased from 21% +/- 14.8% to 55% +/- 13.5% and HbF/F cell increased from 17% to 24%. In the HU nonresponders HbF levels increased from 2.28% +/- 1.61% to 2.6% +/- 2.15% on HU, whereas on 5-aza-CdR HbF increased to 12.70% +/- 1.81%. Total hemoglobin increased by 1 g/dL in 6 of 8 patients with only minor reversible toxicities, and all patients tolerated the drug. Maximum HbF was attained within 4 weeks of treatment and persisted for 2 weeks before falling below 90% of the maximum. Therefore 5-aza-CdR could be effective in increasing HbF in patients with sickle cell anemia who failed to increase HbF with HU. Demonstration of sustained F levels with additional treatment cycles without toxicity is currently being performed.

Therapeutic plasmapheresis and protein A immunoadsorption in malignancy: a brief review

Plasmapheresis is being used with considerable frequency in the management of malignant and non-malignant disorders. More recently, staphylococcal Protein A immunoadsorption has been employed in similar clinical situations. In patients with malignancy, plasmapheresis has been shown to produce alterations in plasma proteins, decrease circulating immune complexes, remove "specific" and "non-specific" blocking factors, change immune reactivity, and affect monocyte function. Partial responses have been reported in a small number of patients with carcinoma of lung, colon, and breast following plasmapheresis. In addition, there are reports of favorable responses in patients with melanoma, head and neck tumors, lymphomas, leukemias, and Kaposi's sarcoma in acquired immune deficiency. All these responses were partial and brief, and the treatment did not alter the course of the disease. Plasmapheresis has been useful in the management of hyperviscosity and occasionally of paraneoplastic syndromes. It may also have a role in the treatment of thrombotic thrombocytopenic purpura associated with mitomycin-C therapy. Protein A immunoadsorption, by which circulating immune complexes are selectively removed, can activate the complement system, increase blastogenic responses, and increase the natural killer cell activity. It has been shown to produce partial responses in breast and colon cancer, as well as Kaposi's sarcoma in acquired immune deficiency. It may have a useful role to play in the management of mitomycin-C-associated thrombotic thrombocytopenic purpura. Both plasmapheresis and Protein A immunoadsorption should be considered investigational interventions at this time. Toxicity of plasmapheresis, though uncommon, can be serious and may rarely be fatal. Toxicity of Protein A immunoadsorption is mild, consisting mainly of influenza-like symptoms and rash.