A Report from the GRNDaD Multi-site Registry for Sickle Cell Disease: Iron Overload is Under-recognized and Under-managed

Introduction: GRNDaD is a prospective registry for people with SCD that opened to enrollment in 2016. Nine comprehensive SCD centers from across the United States are currently enrolling patients. The registry includes iron status and management data, important in SCD because chronic transfusion therapy is a mainstay of prophylactic management. Each unit of transfused blood introduces approximately 250 mg of iron into the blood, which can lead to systemic iron deposition, and untreated may lead to organ dysfunction or death. Methods: GRNDaD currently contains prospective baseline and annual update information on approximately 1000 people with SCD. We analyzed ferritin levels relative to genotype, age, gender, treatment type, liver iron scan results, and chelation therapy history, using chi-squared and pearson statistics for discrete and continuous data, respectively. Results: There were 783 adults in GRNDaD who had a non-crisis ferritin level from a routine follow-up visit. Nearly 1 in 3 of all participants (n=187, 31.4%) had a baseline ferritin ≥1500 mg/dL. More than a third of that group were not on chelation, and only a quarter had imaging studies to assess iron accumulation. Ferritin levels were positively associated with liver enzymes, creatinine, and homozygous SCD phenotype. Conclusion: A significant fraction of the adult SCD population in GRNDaD is living with iron overload, and management could use vast improvement. We speculate that undertreated iron overload is probably both widespread and under-recognized. We anticipate that GRNDaD may be a model for identifying and addressing deficiencies in current clinical practices for management of SCD

A phase 1/2 trial of HQK-1001, an oral fetal globin inducer, in sickle cell disease

Therapeutics which reduce the pathology in sickle cell syndromes are needed, particularly non-cytotoxic therapeutics. Fetal hemoglobin (HbF, α2γ2) is established as a major regulator of disease severity; increased HbF levels correlate with milder clinical courses and improved survival. Accordingly, sodium dimethylbutyrate (HQK-1001), an orally-bioavailable, promoter-targeted fetal globin gene-inducing agent, was evaluated in a randomized, blinded, dose-ranging Phase I/II trial in 24 adult patients with HbSS or S/β thalassemia, to determine safety and tolerability of three escalating dose levels. The study therapeutic was administered once daily for two 6-week cycles, with a 2-week interim dose holiday. Twenty-one patients completed the study. Five patients received study drug at 10 or 20 mg/kg doses, seven patients received study drug at 30 mg/kg/dose, and 4 patients received placebo. HQK-1001 was well-tolerated with no unexpected drug-related adverse events; a dose-limiting toxicity was not identified. Plasma drug levels were sustained above targeted levels for 24 hours. Increases in HbF above baseline were observed particularly with 30 mg/kg/day doses; in five of seven treated patients, a mean absolute increase in HbF of 0.2 g/dl and a mean increase in total hemoglobin (Hgb) of 0.83 g/dl above baseline were observed, whereas no increases occurred in placebo-treated controls. These findings of favorable PK profiles, tolerability, early rises in HbF and total Hgb indicate that trials of longer duration appear warranted to more definitively evaluate the therapeutic potential of HQK-1001 in sickle cell disease

Causes and Outcomes of the Acute Chest Syndrome in Sickle Cell Disease

Background The acute chest syndrome is the leading cause of death among patients with sickle cell disease. Since its cause is largely unknown, therapy is supportive. Pilot studies with improved diagnostic techniques suggest that infection and fat embolism are underdiagnosed in patients with the syndrome. Methods In a 30-center study, we analyzed 671 episodes of the acute chest syndrome in 538 patients with sickle cell disease to determine the cause, outcome, and response to therapy. We evaluated a treatment protocol that included matched transfusions, bronchodilators, and bronchoscopy. Samples of blood and respiratory tract secretions were sent to central laboratories for antibody testing, culture, DNA testing, and histopathological analyses. Results Nearly half the patients were initially admitted for another reason, mainly pain. When the acute chest syndrome was diagnosed, patients had hypoxia, decreasing hemoglobin values, and progressive multilobar pneumonia. The mean length of hospitalization was 10.5 days. Thirteen percent of patients required mechanical ventilation, and 3 percent died. Patients who were 20 or more years of age had a more severe course than those who were younger. Neurologic events occurred in 11 percent of patients, among whom 46 percent had respiratory failure. Treatment with phenotypically matched transfusions improved oxygenation, with a 1 percent rate of alloimmunization. One fifth of the patients who were treated with bronchodilators had clinical improvement. Eighty-one percent of patients who required mechanical ventilation recovered. A specific cause of the acute chest syndrome was identified in 38 percent of all episodes and 70 percent of episodes with complete data. Among the specific causes were pulmonary fat embolism and 27 different infectious pathogens. Eighteen patients died, and the most common causes of death were pulmonary emboli and infectious bronchopneumonia. Infection was a contributing factor in 56 percent of the deaths. Conclusions Among patients with sickle cell disease, the acute chest syndrome is commonly precipitated by fat embolism and infection, especially community-acquired pneumonia. Among older patients and those with neurologic symptoms, the syndrome often progresses to respiratory failure. Treatment with transfusions and bronchodilators improves oxygenation, and with aggressive treatment, most patients who have respiratory failure recover

Combined chelation therapy with deferasirox and deferoxamine in thalassemia.

Iron overload is the primary cause of mortality and morbidity in thalassemia major despite advances in chelation therapy. We performed a pilot clinical trial to evaluate the safety and efficacy of combined therapy with deferasirox (DFX, 20-30 mg/kg daily) and deferoxamine (DFO, 35-50mg/kg on 3-7 days/week) in 22 patients with persistent iron overload or organ damage. In the 18 subjects completing 12 months of therapy, median liver iron concentration decreased by 31% from 17.4 mg/g (range 3.9-38.2mg/g) to 12.0mg/g (range 0.96-26.7 mg/g, p<0.001). Median ferritin decreased by 24% from 2465 ng/mL (range 1110-10,700 ng/mL) to 1875 ng/mL (range 421-5800 ng/mL, p=0.002). All 6 subjects with elevated myocardial iron showed improvement in MRI T2* (p=0.031). The mean±S.E. plasma non-transferrin-bound iron (NTBI) declined from 3.10±0.25μM to 2.15±0.29μM (p=0.028). The administration of DFX during infusion of DFO further lowered NTBI (-0.28±0.08 μM, p=0.004) and labile plasma iron (LPI, -0.03±0.01 μM, p=0.006). The simultaneous administration of DFO and DFX rapidly reduced systemic and myocardial iron, and provided an excellent control of the toxic labile plasma iron species without an increase in toxicity

Emergency department utilization by Californians with sickle cell disease, 2005–2014

Clinical care for children and adults living with sickle cell disease (SCD) is often provided in the emergency department (ED). Population-based surveillance data can be used to describe the ED utilization patterns of this patient population. A cohort of pediatric and adult California patients with SCD was identified from multiple data sources, and 10 years (2005-2014) of their treat-and-release ED utilization data were analyzed. Among a cohort of 4,636 patients with SCD, 4,100 (88%) had one or more treat-and-release ED visits. There were 2.1 mean annual visits per person for the cohort (median 0.7; range 0-185). In a single year (2005), 53% had 0 treat-and-release ED visits, 35% had 1-3 visits, 9% had 4-10 visits, and 3% had 11 or more visits; this highest utilization group accounted for 45% of all patients' ED visits. ED utilization in this cohort was highest among young adults and also higher among older adults than pediatric patients. The majority of identified patients in each of the 10 years did not go to the ED, but nearly all had one or more such visits over the full span of time. This study highlights the power and utility of a multisource longitudinal data collection effort for SCD. Further study of the segment of the population with highest ED utilization may highlight areas where changes in healthcare and health policy could improve and extend the lives of patients with SCD

Neuroimaging abnormalities in adults with sickle cell anemia

ObjectiveThis study was conducted to determine the relationship of frontal lobe cortical thickness and basal ganglia volumes to measures of cognition in adults with sickle cell anemia (SCA).MethodsParticipants included 120 adults with SCA with no history of neurologic dysfunction and 33 healthy controls (HCs). Participants were enrolled at 12 medical center sites, and raters were blinded to diagnostic group. We hypothesized that individuals with SCA would exhibit reductions in frontal lobe cortex thickness and reduced basal ganglia and thalamus volumes compared with HCs and that these structural brain abnormalities would be associated with measures of cognitive functioning (Wechsler Adult Intelligence Scale, 3rd edition).ResultsAfter adjusting for age, sex, education level, and intracranial volume, participants with SCA exhibited thinner frontal lobe cortex (t = -2.99, p = 0.003) and reduced basal ganglia and thalamus volumes compared with HCs (t = -3.95, p < 0.001). Reduced volume of the basal ganglia and thalamus was significantly associated with lower Performance IQ (model estimate = 3.75, p = 0.004) as well as lower Perceptual Organization (model estimate = 1.44, p = 0.007) and Working Memory scores (model estimate = 1.37, p = 0.015). Frontal lobe cortex thickness was not significantly associated with any cognitive measures.ConclusionsOur findings suggest that basal ganglia and thalamus abnormalities may represent a particularly salient contributor to cognitive dysfunction in adults with SCA