Concentration of voxelotor in sickle cell disease can be estimated using electrophoresis and high-performance liquid chromatography.

OBJECTIVES: Voxelotor can increase hemoglobin levels in patients living with sickle cell disease (SCD). A clinician who is monitoring voxelotor response may want to know whole-blood voxelotor concentration, but this cannot be measured in most clinical settings. However, voxelotor has been demonstrated to cause "peak splitting" in common methods of hemoglobin measurement such as capillary zone electrophoresis (CZE) and high-performance liquid chromatography (HPLC). We hypothesized that we could use the size of the peak split to estimate the whole-blood concentration. METHODS: Blood from people with SCD was dosed with known concentrations of voxelotor, and multiparameter regression was used to derive the relationship of voxelotor concentration to the degree of peak splitting observed. To validate these equations, 21 patients started on voxelotor at 1500 mg/d had blood samples drawn at days 0, 14, 30, and 60. Samples were sent out for gold standard voxelotor concentration testing. The derived equations were then used to calculate voxelotor concentration. RESULTS: Calculated concentrations correlated strongly with measured concentrations for both CZE (R2 = 0.83, P < .001) and HPLC (R2 = 0.76, P < .001). Voxelotor concentration also had a significant effect on increases in hemoglobin (R2 = 0.40, P < .001). CONCLUSIONS: Thus, peak splitting CZE and HPLC can be used to estimate voxelotor concentration.

Riociguat in patients with sickle cell disease and hypertension or proteinuria (STERIO-SCD): a randomised, double-blind, placebo controlled, phase 1-2 trial.

BACKGROUND: Although nitric oxide based therapeutics have been shown in preclinical models to reduce vaso-occlusive events and improve cardiovascular function, a clinical trial of a phosphodiesterase 5 inhibitor increased rates of admission to hospital for pain. We aimed to examine if riociguat, a direct stimulator of the nitric oxide receptor soluble guanylate cyclase, causes similar increases in vaso-occlusive events. METHODS: This was a phase 1-2, randomised, double blind, placebo-controlled trial. Eligible patients were 18 years or older, had confirmed sickle cell disease documented by haemoglobin electrophoresis or HPLC fractionation (haemoglobin SS, SC, Sß-thalassemia, SD, or SO-Arab), and stage 1 hypertension or proteinuria. Participants were randomly assigned 1:1 to receive either riociguat or matching placebo via a web-based system to maintain allocation concealment. Both treatments were administered orally starting at 1·0 mg three times a day up to 2·5 mg three times a day (highest tolerated dose) for 12 weeks. Dose escalation by 0·5 mg was considered every 2 weeks if systolic blood pressure was greater than 95 mm Hg and the participant had no signs of hypotension; otherwise, the last dose was maintained. The primary outcome was the proportion of participants who had at least one adjudicated treatment-emergent serious adverse event. The analysis was performed by the intention-to-treat. This trial is registered with ClinicalTrials.gov (NCT02633397) and was completed. FINDINGS: Between April 11, 2017, and Dec 31, 2021, 165 participants were screened and consented to be enrolled into the study. Of these, 130 participants were randomly assigned to either riociguat (n=66) or placebo (n=64). The proportion of participants with at least one treatment-emergent serious adverse event was 22·7% (n=15) in the riociguat group and 31·3% (n=20) in the placebo group (difference -8·5% [90% CI -21·4 to 4·5]; p=0·19). A similar pattern emerged in other key safety outcomes, sickle cell related vaso-occlusive events (16·7 [n=11] vs 21·9% [n=14]; difference -5·2% [-17·2 to 6·5]; p=0·42), mean pain severity (3·18 vs 3·32; adjusted mean difference -0·14 [-0·70 to 0·42]; p=0·69), and pain interference (3·15 vs 3·12; 0·04 [-0·62 to 0·69]; p=0·93) at 12 weeks were similar between groups. Regarding the key clinical efficacy endpoints, participants taking riociguat had a blood pressure of -8·20 mm Hg (-10·48 to -5·91) compared with -1·24 (-3·58 to 1·10) in those taking placebo (-6·96 mm Hg (90% CI -10·22 to -3·69; p<0·001). INTERPRETATION: Riociguat was safe and had a significant haemodynamic effect on systemic blood pressure. The results of this study provide measures of effect and variability that will inform power calculations for future trials. FUNDING: Bayer Pharmaceuticals.

Non-crisis related pain occurs in adult patients with sickle cell disease despite chronic red blood cell exchange transfusion therapy.

BACKGROUND: Chronic red blood cell transfusions reduce acute care utilization for sickle cell disease (SCD) pain. However, little is known about whether chronic transfusions treat or prevent the development of non-crisis pain. We investigated patient-report of pain in adults with SCD receiving chronic exchange transfusions (CET) compared to adults not on CET with similar disease characteristics. STUDY METHOD AND DESIGN: Eleven participants receiving chronic exchange transfusion (CET) for at least one year were compared to 33 participants not receiving CET. Participants completed validated patient-reported outcomes regarding pain impact and quality of life at regularly scheduled visits or before CET. One year of health care utilization and opioid prescriptions were examined. RESULTS: After 1:1 propensity matching was performed for age, genotype, WBC and neutrophil counts, patients on CET had lower Pain Impact scores (-5.1, p = 0.03) and higher Neuropathic (7.4, p < 0.001) and Nociceptive Pain Quality (3.7, p < 0.001) scores, all indicating worse pain. However, CET was associated with a reduction in annual all cause admissions (-3.1, p < 0.001), length of stay (-2.1 days, p < 0.001) and ED visits (-2.7, p < 0.001). CET was not associated with differences in opioids dispensed. CONCLUSIONS: After adjusting for disease characteristics, CET was associated with worse pain impact and neuropathic and nociceptive pain quality, lower health care utilization and with similar levels of opioids dispensed. This data suggest that CET may reduce hospitalizations for acute pain but may not adequately treat nociceptive or neuropathic pain in SCD.

Clinical Approaches to Cannabis: A Narrative Review.

Cannabis use in the United States is growing at an unprecedented pace. Most states in the United States have legalized medical cannabis use, and many have legalized nonmedical cannabis use. In this setting, health care professionals will increasingly see more patients who have questions about cannabis use, its utility for medical conditions, and the risks of its use. This narrative review provides an overview of the background, pharmacology, therapeutic use, and potential complications of cannabis.

Daily Cannabis Users with Sickle Cell Disease Show Fewer Admissions than Others with Similar Pain Complaints.

Introduction: Previous studies have shown that cannabis use is common in adults with sickle cell disease (SCD), and that many patients report using cannabis to treat pain. Methods: We performed a cross-sectional study of adults with SCD and compared daily users of cannabis with others using validated patient-reported measures of pain and quality of life as well as opioid and health care utilization. Results: Daily cannabis users with SCD had worse pain episode severity scores than others (56.7 vs. 48.8, p=0.02) yet had 1.8 fewer annual admissions (p=0.01) and 1.2 fewer annual emergency room (ER) visits (p=0.01), and similar amounts of opioids dispensed to others after matching for age, gender, SCD genotype, hydroxyurea use, and pain impact scores. Conclusions: We show that people with SCD with more severe pain crisis are more likely to use daily cannabis, yet have lower rates of hospital admission and ER use as compared with others with similar disease severity and pain impact. Randomized controlled trials should be performed.

Medical marijuana certification for patients with sickle cell disease: a report of a single center experience.

More than one-third of adults with sickle cell disease (SCD) report using cannabis-based products. Many states list SCD or pain as qualifying conditions for medical marijuana, but there are few data to guide practitioners whether or whom should be certified. We postulated that certifying SCD patients may lead to a reduction in opioid use and/or health care utilization. Furthermore, we sought to identify clinical characteristics of patients who would request this intervention. Retrospective data obtained over the study period included rates of health care and opioid utilization for 6 months before certification and after certification. Patients who were certified but failed to obtain medical marijuana were compared with those who obtained it. Patients who were certified were invited to participate in a survey regarding their reasons for and thoughts on certification. Patients who were certified for medical marijuana were compared with 25 random patients who did not request certification. Fifty adults with SCD were certified for medical marijuana and 29 obtained it. Patients who obtained medical marijuana experienced a decrease in admission rates compared with those who did not and increased use of edible cannabis products. Neither group had changes in opioid use. Patients who were certified for medical marijuana had higher rates of baseline opioid use and illicit cannabis use compared with those who did not request certification. Most patients with SCD who requested medical marijuana were already using cannabis illicitly. Obtaining medical marijuana decreased inpatient hospitalizations.

Urinary cannabinoid mass spectrometry profiles differentiate dronabinol from cannabis use.

BACKGROUND: Dronabinol is used to treat a variety of conditions, including loss of appetite in people with AIDS and severe nausea and vomiting caused by cancer chemotherapy. Its therapeutic potential for pain management is now being explored in specific populations. Monitoring dronabinol compliance is challenging because its active ingredient, Δ-9-tetrahydrocannabinol (THC), is also present in cannabis. We developed a rapid LC-MS/MS assay with minimal specimen preparation to quantitate 11 cannabinoids in urine. Using this assay coupled with urine samples from normal controls, cannabis, and dronabinol users, we show the ability to differentiate cannabis from dronabinol use. METHODS: Residual clinical urine samples from 55 cannabinoid positive subjects and 31 negative controls, as well as prospective samples from 5 patients receiving dronabinol therapy were obtained for analysis. RESULTS: In the dronabinol group, only the THC metabolites 11-nor-9-carboxy-tetrahydrocannabinol (THC-COOH) and 11-hydroxy-Δ-9-tetrahydrocannabinol (THC-OH) were detected. Minor cannabinoids were detected in 91% of cannabis group samples and their detection was more frequent in samples with increased THC metabolite concentrations. Of minor cannabinoids evaluated, cannabigerol (CBG) and cannabidiol (CBD) had the greatest sensitivity in detecting cannabis use. CONCLUSIONS: This method has a high sensitivity for the detection of cannabis use with implications for evaluating dronabinol compliance.

Characterization of circulating and cultured Tfh-like cells in sickle cell disease in relation to red blood cell alloimmunization status.

BACKGROUND: People living with sickle cell disease (SCD) are prone to red blood cell (RBC) alloimmunization. We hypothesized that subjects with alloantibodies (responders) would have differences in circulating T-follicular helper (Tfh)-like cells compared to subjects without alloantibodies (non-responders). MATERIALS AND METHODS: Peripheral blood mononuclear cells were collected from 28 subjects, including those with SCD and controls. Circulating CD4 T-cell subsets were first evaluated at baseline. CD4 T-cell subsets were also evaluated after naïve CD4 T-cells were differentiated into Tfh-like cells following in vitro culture with CD3/CD28 beads, IL-7, IL-12, and Activin A. Transfusion and alloantibody histories were extracted from the electronic medical record. RESULTS: Non-responders had a lower percentage of CD45RA negative Tmemory cells than responders or controls (p<0.05). Notably, there were no differences in circulating Tfh-like cells between any group. However, naïve CD4 T-cells from subjects with SCD were more likely to express CXCR5 after in vitro culture than cells from controls. After culture, CXCR5 expressing cells from responders were more likely to express PD1 and ICOS (16.43 %, sd. 20.23) compared to non-responders (3.69 %, s.d. 3.09) or controls (2.78 %, s.d. 2.04). DISCUSSION: The tendency for naïve CD4 T-cells from responders to differentiate into Tfh-like cells after in vitro culture may suggest these cells are prepared to assist B-cells with antibody production regardless of antigen specificity. Further studies are needed, but it is possible that these results may explain why some responders form RBC alloantibodies with multiple specificities, in addition to RBC autoantibodies and HLA alloantibodies.

Red blood cell alloimmunization is associated with lower expression of FcγR1 on monocyte subsets in patients with sickle cell disease.

BACKGROUND: Despite the clinical significance of red blood cell (RBC) alloantibodies, there are currently no laboratory tests available to predict which patients may be at risk of antibody formation after transfusion exposure. Given their phagocytic and inflammatory functions, we hypothesized that differences in circulating monocytes may play a role in alloimmunization. STUDY DESIGN AND METHODS: Forty-two adults with sickle cell disease (SCD) were recruited, with data extracted from the electronic medical record and peripheral blood analyzed by flow cytometry for total monocytes, monocyte subsets (CD14 high/CD16 low+ classical monocytes, CD14 high/CD16 high+ intermediate monocytes, and CD14 intermediate/CD16 high+ non-classical/inflammatory monocytes), and FcγR1 (CD64) expression. Thirteen "non-responder" patients (non-alloimmunized patients with documented RBC transfusion at the study institution) were compared to 20 alloimmunized "responder" patients, who had a total of 44 RBC alloantibodies identified. RESULTS: There were no significant differences in the percentages of total monocytes, monocyte subsets, or measured cytokines between non-responders and responders. However, non-responders had higher CD64 expression on classical monocytes (MFI mean 3424 ± standard deviation 1141) compared to responders (MFI mean 2285 ± 1501), p = 0.029, and on intermediate monocytes (MFI mean 3720 ± 1191) compared to responders (MFI mean 2497 ± 1640), p = 0.033. CONCLUSIONS: Monocytes and the inflammatory milieu increasingly are being appreciated to play a role in some complications of SCD. The differences in FcγR1 expression on monocyte subsets noted between responders and non-responders, which cannot be directly explained by the serum cytokines evaluated, warrant further investigation.

Be careful of the masquerades: differentiating secondary myelodysplasia from myelodysplastic syndromes in clinical practice.

In patients suspected to have myelodysplastic syndrome (MDS), especially in those patients without cytogenetic abnormalities or blast excess, accurate morphologic review by an expert hematopathologist and meticulous exclusion of other secondary causes of myelodysplasia are vital to establish the diagnosis. Errors in diagnosis can lead to dangerous consequences such as the administration of hypomethylating agents, lenalidomide, or even the use of intensive chemotherapy or allogeneic hematopoietic cell transplantation in patients who do not have an underlying MDS or even a malignant hematopoietic process. Additionally, beyond the possible harm and lack of efficacy of such therapies if the diagnosis of MDS is erroneous, the secondary myelodysplasia and resultant cytopenias are not likely to resolve unless the underlying etiology is identified and addressed. Discriminating a malignant process such as MDS from non-malignant secondary myelodysplasia can be quite challenging, and community hematologists/oncologists should consider referral to specialized physicians (both clinical experts and experienced hematopathologists) if there is any doubt regarding the diagnosis. In this article, we present a representative case series of patients from our own practice who posed diagnostic dilemmas and propose a systematic approach for assessment for secondary causes of myelodysplasia.

Longitudinal Analysis of Patient Specific Predictors for Mortality in Sickle Cell Disease.

INTRODUCTION: White Blood Cell (WBC) count, %HbF, and serum creatinine (Cr), have been identified as markers for increased mortality in sickle cell anemia (SCA) but no studies have examined the significance of longitudinal rate of change in these or other biomarkers for SCA individuals. METHODS: Clinical, demographic and laboratory data from SCA patients seen in 2002 by our hospital system were obtained. Those who were still followed in 2012 (survival cohort) were compared to those who had died in the interim (mortality cohort). Patients lost to follow-up were excluded. Age adjusted multivariable Cox proportional hazards models were constructed to assess hazard ratios of mortality risk associated with the direction and degree of change for each variable. RESULTS: 359 SCA patients were identified. Baseline higher levels of WBC, serum creatinine and hospital admissions were associated with increased mortality, as were alkaline phosphatase and aspartate aminotransaminase levels. Lower baseline levels of %HbF were also associated with increased mortality. When longitudinal rates of change for individuals were assessed, increases in Hb or WBC over patient baseline values were associated with greater mortality risk (HR 1.54, p = 0.02 and HR 1.16, p = 0.01 with negative predictive values of 87.8 and 94.4 respectively), while increasing ED use was associated with decreased mortality (HR 0.84, p = 0.01). We did not detect any increased mortality risk for longitudinal changes in annual clinic visits or admissions, creatinine or %HbF. CONCLUSIONS: Although initial steady state observations can help predict survival in SCA, the longitudinal course of a patient may give additional prognostic information.

Evolving Immunotherapy Approaches for Renal Cell Carcinoma.

Metastatic renal cell carcinoma (mRCC) continues to be associated with high rates of morbidity and mortality. Renal cell carcinoma (RCC) is typically resistant to cytotoxic chemotherapy, and while targeted therapies have activity and prolong progression-free and overall survival, responses are usually not durable. Modulating the immune system with cytokine therapy, vaccine therapy, cell therapy, and checkpoint inhibitors offers hope of prolonged survival. Standard and emerging immune therapy approaches and combinations of immune therapies and other modalities are reviewed.

Elevated Steady State WBC and Platelet Counts Are Associated with Frequent Emergency Room Use in Adults with Sickle Cell Anemia.

INTRODUCTION: Sickle cell anemia has many sequelae that result in emergency department (ED) use, but a minority of patients with sickle cell disease are frequent utilizers and make up the majority of ED visits. If patients who are likely to be frequent ED can be identified in steady state, they can be treated with disease modifying agents in an attempt to reduce ED use frequency. We sought to identify steady state markers for frequent ED use. METHODS: We identified all patients with SS/Sß0 seen at our facilities in 2012. Health care utilization over the entire year was calculated and ED visit numbers categorized as either 0-1, 2-5, or 6 or more visits a year. Steady state and acutely active laboratory parameters were collected and analyzed using analysis of variance models and odds ratios. RESULTS: 432 adult sickle cell patients were identified, ages 18-87, 54% female, and 38% had been prescribed hydroxyurea. Of the 432 patients,192 had 0-1 visits in the year, 144 had 2-5 visits in the year, and 96 had >6 visits for a total of 2259 visits. Those who had >6 visits accounted for 1750 (77%) of the total visits for the year. When steady state laboratory markers were examined, each additional 50x10(9)/L platelets was associated with 22% greater risk (p < .001); each 1x10(9)/L of WBC was associated with 11% greater risk (p = .003), and each 1g/dL Hb was associated with 23% lower risk (p = .007) of >6 ED visits/year. We did not observe a relationship between baseline HbF, LDH or reticulocyte count with >6 ED visits. CONCLUSION: Patients with elevated white blood cell counts, elevated platelet counts, and low hemoglobin levels exhibited higher risk for frequent ED utilization and could be candidates for early and aggressive therapy with disease modifying agents.