Updates in SCD: Posters from the 64th ASH Annual Meeting

The American Society of Hematology’s (ASH) 64th Annual Meeting and Exposition featured ASH Poster Walks, which highlighted key posters on the latest clinical updates and therapeutic advancements in hematology care. Here are some of the latest updates from the ASH Poster Walk on What's Hot in Sickle Cell Disease Research 2022.

Clinical Insights on Mortality in Adults with Sickle Cell Disease

To identify and address barriers to quality care for patients with sickle cell disease (SCD), the National Heart and Lung and Blood Institute (NHLBI) established the Sickle Cell Disease Implementation Consortium (SCDIC) in eight different sites in the United States. To better understand the causes of death in SCD, the SCDIC evaluated clinical co-morbidities and clinical phenotypes to see if they could predict a patient’s survival rate.

This research study was comprised of 2,444 patients from the ages of 15 to 45 and measured key patient demographics, including SCD phenotypes, baseline laboratory values, comorbidities, medication usage, and patient-reported outcomes such as quality of life.

Data were collected from the patients for approximately 1.76 years. To determine the relationship between clinical co-morbidities to mortality, logistic regression was used after adjusting for SCD phenotype and the patient’s age group. A separate model was run for each co-morbidity, with SCD phenotype, age group, and co-morbidity being retained in the model.

Throughout the study, 84 patients died, and 78 of the deaths were caused by chronic kidney disease, end-stage renal disease, pulmonary arterial hypertension, sarcoidosis, iron overload, anxiety, depression, and increased acute care utilization. The research study concluded that SCD continuously reduces the life expectancy of individuals affected by this disease, and more work is needed to be done to find comprehensive and supportive care to prevent the characteristics associated with a low survival rate.

The Trajectory of Blood Pressure in Pregnant Patients With Sickle Cell Disease

Pregnant patients with sickle cell disease (SCD) are at high risk of adverse outcomes such as hypertensive disorders of pregnancy (HDP), and HDP can lead to acute and chronic morbidity for not only the pregnant patient but also the fetus. But normal parameters for blood pressure (BP) in SCD haven’t been set. In the general population, BP decreases during pregnancy and returns to baseline peripartum. But more data is needed on the trajectory of BP across pregnancy in patients with SCD to better inform clinicians’ treatment decisions.

To better understand this trajectory, a recent study explored BP across pregnancy in patients with SCD and compares BPs by clinical variables, including genotype and the use of chronic transfusion therapy.

Researchers compared the medical records of patients with SCD who delivered singleton pregnancies of at least 20 weeks gestation at Mount Sinai Hospital in Toronto and Johns Hopkins Hospital. They collected laboratory values, SCD complications, comorbidities, medication exposures, transfusion practices, labor and delivery information, and fetal outcomes, and documented the highest systolic and diastolic blood pressure captured in seven time periods: before pregnancy, at the initial prenatal visit, 20-28 weeks gestation, 28-34 weeks gestation, last outpatient visit before delivery, admission for birth, and six weeks postpartum.

Researchers also compared demographic and clinical features in people with hemoglobin-SS or hemoglobin-Sβ0 thalassemia (HbSS/HbSβ⁰) to those with hemoglobin-SC or hemoglobin-Sβ+ thalassemia (HbSC/HbSβ⁺)

Out of 292 singleton pregnancies, researchers found that BP trajectories matched the pattern typically seen in healthy pregnant people. Systolic BP dropped at 20-28 weeks gestation, peaked during labor, and returned to baseline by six weeks postpartum. These trajectories also differed by genotype group.

Overall, the study showed that the risk of HDP based on existing definitions was similar in HbSS/HbSβ⁰ and HbSC/HbSβ⁺ groups. Those with HbSS/HbSβ⁰ had lower baseline BP than those with HbSC/HbSβ⁺. HbSS/HbSβ⁰ patients don’t undergo the same cardiovascular adaptations as the general population due to reduced cardiovascular reserve. BP trajectory in the HbSC/HbSβ⁺ was similar to the non-SCD pregnant population.

Researchers concluded by recommending that appropriate BP thresholds be developed to define HDPs in SCD.