Promise of Composite Pain Index as a single pain outcome for sickle cell disease across the lifespan

BACKGROUND

This study aimed to validate a Composite Pain Index (CPI) as a single pain outcome measure for sickle cell disease (SCD) across the lifespan from 8 years of age.

PROCEDURE

This prospective, cross-sectional study included 55 participants with SCD who completed the PAINReportIt tool and Adolescent Pediatric Pain Tool (APPT) in random order during outpatient visits to derive respective CPI scores for comparison.

RESULTS

Of the 55 participants with SCD, 46 (84%) had HgbSS, eight (15%) HgbSC, and one (2%) HgbSβ0+. The mean age of all participants was 17.5 ± 2.6 years, and 28 (51%) were female, 52 (95%) were Black, 42 (98%) were non-Hispanic, and 39 (71%) had a ninth grade or higher education. Correlation analyses between the APPT and PAINReportIt revealed positive associations for the number of pain sites (r = .57, p < .001), pain intensity (r = .46, p < .001), pain quality (r = .74, p < .001), and pain pattern (r = .34, p = .01). Patients' mean CPI scores derived from the PAINReportIt was slightly higher than the APPT; 34.2 (SD = 14.7) and 30.0 (SD = 19.0), respectively. Regression analyses showed that the APPT CPI significantly predicted the PAINReportIt CPI (B = .497, t(53) = 6.051, p < .001). This finding holds true even when accounting for the order of measurement or patient's age.

CONCLUSION

The initial validation of CPI as a single pain outcome measure represents a significant advancement in pain assessment for SCD. Further validation is warranted for the CPI as a measure is for both clinicians and researchers to enable longitudinal pain assessment from age 8 years across the lifespan as children age into adult care.

Monitoring and responding to signals of suicidal ideation in pragmatic clinical trials: Lessons from the GRACE trial for Chronic Sickle Cell Disease Pain

Sickle cell disease (SCD) is a hemoglobin disorder and the most common genetic disorder that affects 100,000 Americans and millions worldwide. Adults living with SCD have pain so severe that it often requires opioids to keep it in control. Depression is a major global public health concern associated with an increased risk in chronic medical disorders, including in adults living with sickle cell disease (SCD). A strong relationship exists between suicidal ideation, suicide attempts, and depression. Researchers enrolling adults living with SCD in pragmatic clinical trials are obligated to design their methods to deliberately monitor and respond to symptoms related to depression and suicidal ideation. This will offer increased protection for their participants and help clinical investigators meet their fiduciary duties. This article presents a review of this sociotechnical milieu that highlights, analyzes, and offers recommendations to address ethical considerations in the development of protocols, procedures, and monitoring activities related to suicidality in depressed patients in a pragmatic clinical trial.

Developing an Implementation Blueprint for the NIH HEAL Initiative GRACE Trial: Perspectives on Acupuncture and Guided Relaxation for Chronic Sickle Cell Disease Pain

Objective: This study aimed to explore perspectives of people living with sickle cell disease (SCD) and SCD clinic providers and staff about the use of acupuncture and guided relaxation for treating chronic SCD pain. Data obtained were to inform an implementation blueprint for an effectiveness implementation clinical trial (GRACE Trial) testing whether acupuncture or guided relaxation reduces chronic pain when compared with usual care. Design: Qualitative research design. Methods: We conducted 33 semistructured interviews with people with SCD and SCD clinic providers and staff. Interviews were transcribed and coded. A deductive content analysis process was used to identify themes. Results: Four themes were identified: Receptivity to Acupuncture and Guided Relaxation, Limited Awareness, Complementary and Integrative Health (CIH) Therapy Preference, and Access Barriers. Both patients and clinic providers and staff were open to the use of acupuncture and guided relaxation for chronic pain treatment. After learning about these CIH therapies, some patients expressed a preference for one therapy over the other. They also discussed their ability to successfully engage with each therapy. There is a need to dispel misconceptions about the therapies by increasing understanding of how each therapy is implemented and functions to reduce pain. We identified several potential barriers that might affect the success of the trial and future health system integration, including time, transportation, and technology. Conclusion: This study is one of the first to present perspectives of both patients with SCD and clinic providers and staff on the use of acupuncture and guided relaxation for chronic SCD pain. Stakeholders' early input and perspectives highlighted that they welcome nonpharmacological CIH therapies. Implementation of a clinical trial and future health system integration will require the addressing misinformation and identifying strategies to overcome access barriers. Clinical trial registration number: NCT04906447.

An alcohol dehydrogenase 7 gene polymorphism associates with both acute and chronic pain in sickle cell disease

Introduction: As the most distressing complication of sickle cell disease (SCD), pain is marked by considerable heterogenicity. In this study we explored the potential association of alcohol dehydrogenase 7 gene (ADH7) polymorphism rs971074 with sickle cell pain. Methods: We analyzed clinical phenotypes and the rs971074 single-nucleotide polymorphism in ADH7 by MassARRAY-iPlex analysis in a cohort of SCD patients. Results: The synonymous rs971074 was significantly associated with both acute and chronic pain in SCD. Patients with the minor T allele(s) recorded significantly more crisis episodes and severe chronic pain symptoms. Conclusion: Our study has identified the rs971074 minor T allele as a genetic biomarker potentially influencing acute and chronic pain. These findings may ultimately help inform strategies to develop precision pain therapies in SCD.

Candidate gene association study suggests potential role of dopamine beta-hydroxylase in pain heterogeneity in sickle cell disease

Introduction: Pain is a lifelong companion of individuals with sickle cell disease (SCD) and has a severe impact on their quality of life. Both acute crisis pain and chronic non-crisis pain exhibit high variability between individuals, making it difficult to effectively manage sickle cell-related pain. We investigated the role of dopamine beta-hydroxylase (DBH) gene polymorphisms on pain variability in SCD. DBH is a key enzyme in the catecholamine biosynthesis pathway that catalyzes the conversion of dopamine to norepinephrine, both of which are known mediators of pain and pain-related behaviors. Methods: Acute crisis pain-related utilization and non-crisis chronic pain scores of 131 African Americans with SCD were obtained. Results and discussion: Association analyses revealed that the T allele of upstream variant rs1611115 and downstream variant rs129882 correlated with higher severity of chronic pain in an additive model. On the other hand, the A allele of missense variant rs5324 associated with lower risk of both acute crisis pain and chronic pain. Similarly, the C allele of intronic variant rs2797849 was associated with lower incidence of acute crisis pain in the additive model. In addition, tissue-specific eQTL revealed that the T allele of rs1611115 correlated with decreased expression of DBH in the frontal cortex and anterior cingulate cortex (GTEx), and decreased expression of DBH-AS1 in blood (eQTLGen). Bioinformatic approaches predicted that rs1611115 may be altering a transcription factor binding site, thereby, contributing to its potential effect. Taken together, findings from this study suggest that potential functional polymorphisms of DBH may modulate pain perception in SCD.

Community-level socioeconomic distress is associated with nutritional status in adults with sickle cell anemia

Sickle cell anemia (SCA) negatively impacts the ability to achieve educational and occupational goals increasing vulnerability to socioeconomic challenges. In a cross-sectional analysis of 332 SCA adults, we investigated whether the distressed community index (DCI) was associated with SCA-related complications and nutritional status. More patients with higher DCI had Medicaid insurance. A higher DCI was independently associated with tobacco use and lower body mass index, serum albumin, and vitamin D 25-OH levels after adjusting for insurance status but was not associated with SCA-related complications. Future studies investigating access to healthy foods may help improve health equity in patients with SCA.

Quantification of Patient-Reported Pain Locations: Development of an Automated Measurement Method

Patient-reported pain locations are critical for comprehensive pain assessment. Our study aim was to introduce an automated process for measuring the location and distribution of pain collected during a routine outpatient clinic visit. In a cross-sectional study, 116 adults with sickle cell disease-associated pain completed PAIN Report It Ⓡ . This computer-based instrument includes a two-dimensional, digital body outline on which patients mark their pain location. Using the ImageJ software, we calculated the percentage of the body surface area marked as painful and summarized data with descriptive statistics and a pain frequency map. The painful body areas most frequently marked were the left leg-front (73%), right leg-front (72%), upper back (72%), and lower back (70%). The frequency of pain marks in each of the 48 body segments ranged from 3 to 79 (mean, 33.2 ± 21.9). The mean percentage of painful body surface area per segment was 10.8% ± 7.5% (ranging from 1.3% to 33.1%). Patient-reported pain locations can be easily analyzed from digital drawings using an algorithm created via the free ImageJ software. This method may enhance comprehensive pain assessment, facilitating research and personalized care over time for patients with various pain conditions.

Hybrid effectiveness-implementation trial of guided relaxation and acupuncture for chronic sickle cell disease pain (GRACE): A protocol

Background

People with sickle cell disease frequently use complementary and integrative therapies to cope with their pain, yet few studies have evaluated their effectiveness. The 3-arm, 3-site pragmatic Hybrid Effectiveness-implementation Trial of Guided Relaxation and Acupuncture for Chronic Sickle Cell Disease Pain (GRACE) has 3 priorities: (1) evaluate guided relaxation and acupuncture to improve pain control; (2) determine the most appropriate and effective treatment sequence for any given patient based on their unique characteristics; and (3) describe the processes and structures required to implement guided relaxation and acupuncture within health care systems.

Methods

Participants (N = 366) are being recruited and randomized 1:1:1 to one of 2 intervention groups or usual care. The acupuncture intervention group receives 10 sessions over approximately 5 weeks. The guided relaxation intervention group receives access to video sessions ranging from 2 to 20 min each viewed daily over 5 weeks. The usual care group receives the standard of clinical care for sickle cell disease. Participants are re-randomized at 6 weeks depending on their pain impact score. Assessments occur at 6 weeks, 12 weeks, and 24 weeks. The primary outcome is the change in pain impact score and secondary measures include opioid use, anxiety, depression, sleep, pain catastrophizing, substance use, global impression of change, constipation, and hospitalizations. The GRACE study uses the Consolidated Framework for Implementation Research to plan, execute, and evaluate the associated implementation processes.

Conclusion

The results from GRACE will represent a critical step toward improving management of pain affecting patients with sickle cell disease.ClinicalTrials.gov Identifier: NCT04906447.

Reticulocyte mitochondrial retention increases reactive oxygen species and oxygen consumption in mouse models of sickle cell disease and phlebotomy-induced anemia

Sickle cell disease (SCD) is caused by a mutation of the β-globin gene that results in the production of hemoglobin S (HbS). People with SCD experience anemia, severe acute pain episodes, persistent chronic pain, multiorgan damage, and a reduced life span. The pathophysiology of SCD caused by the polymerization of HbS on deoxygenation results in red cell deformability and the generation of reactive oxygen species (ROS). These 2 factors lead to red cell fragility and hemolysis. Reticulocytosis is an independent predictor of disease morbidity and mortality in SCD. We previously established that humans and mice with SCD exhibit abnormal mitochondrial retention in erythrocytes increasing ROS-associated hemolysis. Here, we investigated the hypothesis that mitochondrial retention and increased ROS are a consequence of stress erythropoiesis. Our results show clearly that stress erythropoiesis in phlebotomized, anemic AA mice results in mitochondrial retention and increased ROS in reticulocytes. We observed that elevated mitochondrial retention in reticulocytes also alters oxygen consumption and potentially contributes to increased HbS polymerization and red blood cell hemolysis. Therefore, these events occurring due to stress erythropoiesis contribute significantly to the pathology of SCD and suggest new therapeutic targets.

Analysis of AVPR1A, thermal and pressure pain thresholds, and stress in sickle cell disease

Aim

In patients with sickle cell disease (SCD), negative physical and emotional experiences result from intense chronic and acute pain episodes, but factors underlying these, and their interactions, are not well understood. The arginine vasopressin receptor 1a gene (AVPR1A) single nucleotide polymorphism rs10877969 has been previously associated with aspects of acute pain and stress related pain. In this study, we tested for associations between this SNP, thermal and pressure pain thresholds, clinical pain, and stress in people with SCD.

Methods

150 adults enrolled with SCD completed pain intensity measures (Average Pain Intensity, API) and the Perceived Stress Questionnaire (PSQ). Thermal and pressure pain threshold data were available from quantitative sensory testing (QST), and rs10877969 genotypes were obtained.

Results

In models adjusted for age and gender, between rs10877969 genotypes, we observed no significant differences in thermal (cold, p = 0.66; heat, p = 0.91) and mechanical (pressure, p = 0.33) pain thresholds. The association of rs10877969 with API (p = 0.09) was borderline, but non-significant with PSQ (p = 0.51). The correlation between clinical pain and environmental stress was significant, r = 0.18, p = 0.024, however, the interaction of genotype and PSQ was not significant (p = 0.63).

Conclusion

Clinical and experimental pain were not significantly associated with the rs10877969 genotype. The rs10877969 genotype did not moderate the correlation between environmental stress and clinical pain in this population. However, a trend toward a protective T allele effect on average pain rating in SCD warrants future exploration of this SNP/gene in SCD.

A Novel Measure of Pain Location in Adults with Sickle Cell Disease

BACKGROUND

Pain intensity remains a primary focus clinically for sickle cell disease pain assessment despite the fact that pain quality and pain location and distribution are critical for clinical diagnosis and treatment of its etiology. However, in part because of measurement issues, scant evidence is available about pain location or its relationship to intensity and quality in adults with SCD.

AIM

Our study aim was to examine sickle cell disease pain location for relationships with pain quality and intensity measured in outpatient and inpatient settings.

METHODS

We used an existing longitudinal dataset prospectively collected with the valid and reliable tablet-based PAINReportItⓇ. Adults with sickle cell disease (n = 99) reported pain location, intensity, and quality during a routine outpatient clinic visit and again during a subsequent hospitalization. From their digital body outline drawings and using the ImageJ software, we computed the pain-affected body surface area. With Pearson's correlations and paired t tests, we examined relationships between pain-affected body surface area and other pain variables across outpatient and inpatient visits.

RESULTS

The mean pain-affected body surface area was 14.4% ± 15.0% of the total body surface area for outpatient visits (min-max: 0.0%-90.2%) and 13.5% ± 14.7% (min-max: 0.0%-73.0%) for inpatient stay. Pain-affected body surface area was positively correlated with pain quality scores for both visits but not significantly correlated with pain intensity at either visit. Compared with the outpatient visit, mean pain intensity for inpatient stay was higher (p < .001); pain quality (p = .12) and pain-affected body surface area (p = .60) did not differ significantly between visits.

CONCLUSIONS

Unknown is the explanation for pain-affected body surface area association with SCD pain quality but not pain intensity at outpatient and inpatient visits. Additional research is warranted to explore these findings and examine the clinical utility of pain-affected body surface area for chronic sickle cell disease pain and acute sickle cell disease crisis pain.

HUMAN STUDY COMT and DRD3 haplotype-associated pain intensity and acute care utilization in adult sickle cell disease

A previous exploratory analysis of a COMT gene single-nucleotide polymorphism (SNP) and a DRD3 SNP by our group suggested possible contributions to pain-related acute care utilization in people with sickle cell disease (SCD). Our aim was to extend the analysis to gene-spanning haplotypes of COMT SNPs and DRD3 SNPs to investigate possible associations with pain intensity and pain-related acute care utilization in an SCD cohort. Genotyping was conducted, and clinical data were collected, including self-reported pain intensity using PAINReportIt^® (average of current pain and least and worst in past 24 hours, average pain intensity [API]) and medical record-extracted, pain-related acute care utilization data of 130 adults with SCD. Haplotype blocks were identified based on linkage disequilibria (COMT = 7 haploblocks; DRD3 = 8 haploblocks). Regression analyses were tested for association between haplotypes and API and utilization, yielding several significant findings. For COMT block 1 (rs2075507, rs4646310, rs737865), the A-G-G haplotype was associated with higher API compared to the reference A-G-A (p = 0.02), whereas the A-A-A haplotype was associated with higher utilization (p = 0.02). For DRD3 block 2 (rs9817063, rs2134655, rs963468, and rs3773679), relative to reference T-C-G-C, the T-T-G-C haplotype was associated with higher utilization (p = 0.01). For DRD3 block 4 (rs167770, rs324029, and rs324023), the A-G-T haplotype was associated with higher API (p = 0.04) and utilization (p < 0.001) relative to reference G-A-T, whereas the A-A-T haplotype was associated with higher utilization (p = 0.01). We found COMT and DRD3 haplotypes associated with pain-related SCD features, suggesting that in future studies more emphasis be placed on cis effects of SNP alleles in evaluating genetic contributions to SCD pain and acute care utilization for pain.

Acupuncture for chronic pain in adults with sickle cell disease: a mixed-methods pilot study

OBJECTIVE

Chronic pain is a common symptom experienced among patients with sickle cell disease (SCD). Our aims were to assess the feasibility and acceptability of performing acupuncture for the treatment of chronic pain in adults with SCD.

METHODS

This was a single-arm, prospective pilot study of six adults with SCD. Participants reported ⩾ 3 months of chronic pain and were > 18 years of age. Per protocol, acupuncture was to be administered twice per week for 5 weeks, for 30 min per session. All treatments were performed in the acupuncture treatment laboratory at the University of Illinois Chicago College of Nursing. Pain intensity, pain interference, and other symptoms were measured at baseline and after the intervention. Participants completed a semi-structured interview and a protocol acceptability questionnaire after the acupuncture intervention.

RESULTS

Six participants (mean age 52.5 years, six Black) were enrolled. Although the study was suspended due to COVID-19 and not all participants completed the 10-session protocol, completion rates were high with no missed appointments. One participant did not complete the study due to hospitalization unrelated to acupuncture. No adverse events were reported. At completion of the intervention at 4-5 weeks post-baseline, all participants had reduced pain intensity and pain interference. The mean acceptability score on the protocol acceptability questionnaire was 82%.

CONCLUSION

It was feasible and acceptable to implement acupuncture in adults with SCD. This study can be used to guide a larger randomized controlled trial to evaluate the effect of acupuncture on reducing chronic pain in adults with SCD.Trial registration number: NCT04156399 (ClinicalTrials.gov).

Evaluation of point-of-care International Normalized Ratio in sickle cell disease

Background

Point‐of‐care (POC) International Normalized Ratio (INR) measurement provides efficient monitoring of warfarin therapy; however, its reliability may be affected in patients with anemia, such as those with sickle cell disease (SCD).

Objectives

To evaluate the correlation of POC‐INR to clinical laboratory INR (CL‐INR) in SCD and use of a correction factor.

Patient/Methods

In this retrospective study, the accuracy of POC‐INR compared to CL‐INR was evaluated in a cohort of patients with SCD and in a non‐SCD Black cohort.

Results

Despite the difference in anemia, the SCD cohort showed a similar percentage of in‐range POC‐INR values as observed in the non‐SCD cohort (37% vs 42%). The SCD cohort was randomly divided to form discovery and validation cohorts. In the discovery cohort, 86% of POC‐INRs were in range when the POC‐INRs were ˂4.0, but only 24% were in range if POC‐INRs were ≥4.0. A linear regression of CL‐INR versus POC‐INR for POC‐INR values ≥4.0 yielded a coefficient of 0.72 (95% confidence interval, 0.69‐0.75); Multiplying POC‐INR by this correction factor, rounded to 0.7 for ease of use in clinical practice, improved the proportion of in‐range POC‐INR values ≥4.0 from 24% to 100% in the SCD discovery cohort and from 19% to 95% in the SCD validation cohort. Similar findings applied to analyses of the non‐SCD cohort.

Conclusions

POC‐INR and CL‐INR in patients with SCD are similar when POC‐INR is <4.0, and the accuracy of POC‐INR values ≥4.0 can be improved by applying an institution‐specific correction factor.

Pain, symptom distress, and pain barriers by age among patients with cancer receiving hospice care: Comparison of baseline data

OBJECTIVES

Age group differences have been reported for pain and symptom presentations in outpatient and inpatient oncology settings, but it is unknown if these differences occur in hospice. We examined whether there were differences in pain, symptom distress, pain barriers, and comorbidities among three age groups (20-64 years, 65-84 years, and 85+) of hospice patients with cancer.

MATERIALS AND METHODS

Participants were recruited from two hospices. Half were women; 49% White and 34% Black. 42% were 20-64 y, 43% 65-84 y, and 15% 85+ y. We analyzed baseline data for 230 hospice patients with cancer (enrolled 2014-2016, mean age 68.2 ± 14.0, 20-100 years) from a stepped-wedge randomized controlled trial. Measures were the Average pain intensity (API, 0-10: current, least and worst pain intensity during the past 24 h), Symptom Distress Scale (SDS, 13-65), Barriers Questionnaire-13 (BQ-13, 0-5), and comorbid conditions. Descriptive, bivariate association, and multiple regression analyses were performed.

RESULTS

Mean API scores differed (p < .001) among the three age groups (5.6 ± 2.0 [20-64 years], 4.7 ± 2.0 [65-84 years], and 4.4 ± 1.8 [85+], as did the mean SDS scores (36.1 ± 7.3, 33.5 ± 8.1, and 31.6 ± 6.6, p = .004). BQ-13 mean scores (2.6 ± 0.9, 2.7 ± 0.8, and 2.5 ± 0.7) and comorbidities were not significantly different across age groups. In multiple regression analyses, age-related differences in API and SDS remained significant after adjusting for gender, race, cancer, palliative performance score, and comorbidities. Comorbidities were positively associated with SDS (p = .046) but not with API (p = .64) in the regression model.

CONCLUSION

Older hospice patients with cancer reported less pain and symptoms than younger patients, but all groups reported similar barriers to pain management. These findings suggest the need for age- and race-sensitive interventions to reduce pain and symptom distress levels at life's end.

Abstract D044: Age and sex effects on quantitative sensory testing values in healthy African American adults

Introduction: Only a few studies have reported quantitative sensory testing (QST) reference values for healthy African Americans, and those studies are limited in sample size and range of age of participants. The intent of our study was to fill a gap in the understanding of pain and somatosensory function in African Americans by generating QST values for healthy African American adults. In a large cohort of pain-free, healthy African American adults whose past pain experiences and current psychological status were known, our study aim was to determine thermal and mechanical QST values and compare those values at the anterior forearm by age and sex. We also determined the values for 5 other body sites and compared the values for differences by testing site location (upper body versus lower body). Methodology: In this cross-sectional study, 124 pain-free African American adults (age 18 to 69 years, 49% female) completed demographic and self-reported pain, fatigue and psychosocial measures. QST included obtaining thermal and mechanical responses and associated pain intensity levels. We applied the Benjamini-Hochberg procedure to adjust the p values to account for the multiple t tests. Results: We found thermal detection values at the anterior forearm were (29.2°C±1.6) for cool detection (CD) and (34.5°C±1.2) for warm detection (WD). At that site, pain thresholds were: cold pain threshold (CPTh) (26.3°C±5.0), heat pain threshold (HPTh) (37.8°C±3.6), and mechanical pain thresholds (MPTH) (16.7±22.2 grams of force, gF). There was a significant between sex difference for WD, with women being more sensitive (q=0.027). Lower body sites were less sensitive than upper body sites across all thermal modalities (q&lt;0.003), but not for the mechanical modality. Mean pain intensity scores rated immediately after the CPTh and HPTh were 1.9 ± 1.3 to 2.2 ± 1.2 on the 0-10 pain intensity scale. Similarly, after the MPTh tests the mean pain intensity scores were 0.5 ± 0.5 to 0.8 ± 0.6. These scores did not differ significantly by sex or age group and clearly indicate that the participants reported pain threshold at an appropriately low perceptual intensity. Pain intensity values for past pain experiences and low ratings for fatigue, depression and anxiety indicated that these factors were unlikely contributors to their pain threshold reports. Conclusion: The QST values from this protocol at the anterior forearm indicate that healthy African American adults had average thermal pain thresholds within 6°C of the temperature of adaptation and average MPTh under 20 gF. Differences in responses to thermal and mechanical stimuli for upper verses lower body were consistent with prior research. These findings add to the body of literature confirming that African American adults indeed have lower pain thresholds than those reported for White adults. These QST values can be used as controls for African Americans with cancer to understand the neuropathic pain syndromes associated with tumor progression and cancer treatments.

Citation Format: Keesha L. Powell-Roach, Starja Q. Booker, Yingwei Yao, Marie L. Suarez, Miriam O. Ezenwa, Roger B. Fillingim, Zaijie J. Wang, Robert E. Molokie, Diana J. Wilkie. Age and sex effects on quantitative sensory testing values in healthy African American adults [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D044.

S100B single nucleotide polymorphisms exhibit sex-specific associations with chronic pain in sickle cell disease in a largely African-American cohort

BACKGROUND

Pain in sickle cell disease (SCD) is severe and multifaceted resulting in significant differences in its frequency and intensity among individuals. In this study, we examined the influence of S100B gene single nucleotide polymorphisms (SNP) on acute and chronic pain variability in SCD.

METHODS

Composite pain index (CPI) scores captured chronic pain. Painful crisis related emergency care utilization recorded acute pain incidence. Genotyping was performed using MassARRAY iPLEX platform.

RESULTS

Regression analysis revealed associations of increased CPI with rs9722 A allele in additive (p = 0.005) and dominant (p = 0.005) models. Rs1051169 G allele on the other hand was associated with decreased CPI in additive (p = 0.001), and dominant (p = 0.005) models. Sex-specific analysis found that these associations were significant in females but not males in this cohort. Linkage analysis identified two haploblocks. Block 1 (rs9983698-rs9722) haplotype T-A was associated with increased CPI (p = 0.002) while block 2 (rs1051169-rs11911834) haplotype G-G was associated with decreased CPI (p = 0.001). Both haplotypic associations were only significant in females. No association of S100B SNPs with utilization reached statistical significance.

CONCLUSIONS

S100B SNPs and haplotypes are associated with chronic pain in female, but not male, patients with SCD, implicating a potential role of S100B polymorphism in SCD pain heterogeneity in a sex-dependent manner.

Phenylethanolamine N-methyltransferase gene polymorphisms associate with crisis pain in sickle cell disease patients

Aim: Phenylethanolamine N-methyltransferase (PNMT) catalyzes the conversion of sympathetic neurotransmitter norepinephrine to epinephrine. We examined the association of PNMT polymorphisms with acute and chronic pain in sickle cell disease (SCD). Methods: Utilization of emergency care owing to painful crisis was used as a marker for acute pain in 131 patients with SCD. Results: rs876493 A allele, rs2934965 T allele and rs2941523 G allele were significantly associated with decreased utilization (p ≤ 0.05). rs876493 A allele showed association with utilization in females (p = 0.003), not males (p = 0.803). rs2934965 T allele and rs2941523 G allele were predicted to cause loss of putative transcription factor binding sites. This is the first report of the association of PNMT polymorphisms with acute crisis pain in SCD. Together with our previous findings in catechol-o-methyltransferase, polymorphisms in catecholamine metabolizing enzymes appear to primarily influence acute pain in SCD.

A Stepped-Wedge Randomized Controlled Trial: Effects of eHealth Interventions for Pain Control Among Adults With Cancer in Hospice

CONTEXT

Unrelieved cancer pain at the end of life interferes with achieving patient-centered goals.

OBJECTIVE

To compare effects of usual hospice care and PAINRelieveIt® on pain outcomes in patients and their lay caregivers.

METHODS

In a five-step, stepped-wedge randomized, controlled study, 234 patients (49% male, 18% Hispanic, 51% racial minorities) and 231 lay caregivers (26% male, 20% Hispanic, 54% racial minorities) completed pre-pain/post-pain measures. They received usual hospice care with intervention components that included a summary of the patient's pain data, decision support for hospice nurses, and multimedia education tailored to the patient's and lay caregiver's misconceptions about pain.

RESULTS

The intervention effect on analgesic adherence (primary outcome) was not significant. Post-test worst pain intensity was significantly higher for the experimental group, but the difference (0.70; CI = [0.12, 1.27]) was not clinically meaningful. There was nearly universal availability of prescriptions for strong opioids and adjuvant analgesics for neuropathic pain in both groups. Lay caregivers' pain misconceptions (0-5 scale) were significantly lower in the experimental group than the usual care group (mean difference controlling for baseline is 0.38; CI = [0.08, 0.67]; P = 0.01).

CONCLUSION

This randomized controlled trial was a negative trial for the primary study outcomes but positive for a secondary outcome. The trial is important for clearly demonstrating the feasibility of implementing the innovative set of interventions.

Randomized clinical trial of computerized PAINRelieveIt® for patients with sickle cell disease: PAINReportIt® and PAINUCope®

OBJECTIVE

To compare effects of a tailored multimedia education program versus usual-care on barriers to pain management of adult patients with SCD.

METHODS

Pretest/posttest randomized controlled trial (RCT) of 228 outpatients with SCD randomized to the tablet-based PAINUCope intervention focused on barriers to pain management, pain, and analgesic adherence or selection of games (control). Outcomes were barriers to pain management, pain, and analgesic adherence.

RESULTS

The barriers to pain management and pain scores did not change significantly from pretest to posttest for either condition. Changes in analgesic adherence rates from pretest to posttest were statistically significant for the intervention group (p = .046) but not for the usual care group (p = .419). The group difference was not statistically significant.

CONCLUSIONS

This first RCT of a tailored multimedia education intervention with adult patients with SCD did not significantly reduce the outcomes of interest compared to the control group. Findings provide insights for improving intervention delivery and reinforcement of patient behaviors.

PRACTICE IMPLICATIONS

Study redesign is warranted with modifications that include theoretical and methodological approaches and patient-centered delivery of the intervention that take advantage of recent technology developments.

Sensitivities to Thermal and Mechanical Stimuli: Adults With Sickle Cell Disease Compared to Healthy, Pain-Free African American Controls

Evidence supports^, but is inconclusive that sensitization contributes to chronic pain in some adults with sickle cell disease (SCD). We determined the prevalence of pain sensitization among adults with SCD pain compared with pain-free healthy adults. In a cross sectional, single session study of 186 African American outpatients with SCD pain (age 18-74 years, 59% female) and 124 healthy age, gender, and race matched control subjects (age 18-69 years, 49% female), we compared responses to standard thermal (Medoc TSA II) and mechanical stimuli (von Frey filaments). Although we observed no significant differences in thermal thresholds between controls and patients, patients with SCD had lower pain thresholds to mechanical stimuli and reported higher pain intensity scores to all thermal and mechanical stimuli at a non-painful body site. Compared with controls, about twice as many patients with SCD showed sensitization: 12% versus 23% at the anterior forearm site (P = .02), and 16% versus 32% across 3 tested sites (P = .004). Among patients with SCD, 18% exhibited some element of central sensitization. Findings indicate that persistent allodynia and hyperalgesia can be part of the SCD pain experience and should be considered when selecting therapies for SCD pain. PERSPECTIVE: Compared with matched healthy controls, quantitative sensory testing in adults with pain and sickle cell disease (SCD) demonstrates higher prevalence of sensitization, including central sensitization. The findings of allodynia and hyperalgesia may indicate neuropathic pain and could contribute to a paradigm shift in assessment and treatment of SCD pain.

Vasopressin SNP pain factors and stress in sickle cell disease

PURPOSE

Frequencies of single nucleotide polymorphisms (SNPs) from pain related candidate genes are available for individuals with sickle cell disease (SCD). One of those genes, the arginine vasopressin receptor 1A gene (AVPR1A) and one of its SNPs, rs10877969, has been associated with pain and disability in other pain populations. In patients with SCD, clinical factors such as pain and stress have been associated with increased health care utilization, but it is not known if the presence of the AVPR1A SNP plays a role in this observation. The study purpose was to explore the relationships between rs10877969 and self-reported pain, stress, and acute care utilization events among individuals with SCD.

METHODS

In a cross-sectional investigation of outpatients with SCD, participants completed PAINReportIt®, a computerized pain measure, to describe their pain experience and contributed blood or saliva samples for genetic analysis. We extracted emergency department and acute care utilization from medical records.

RESULTS

The SNP genotype frequencies (%) for this sample were CC 30 (28%), CT 44 (41%), TT 33 (31%). Acute care utilization and stress as an aggravator of pain were significantly associated with the rs10877969 genotype (p = .02 and p = .002, respectively). The CT genotype had the highest mean utilization and CC genotype was associated with not citing stress as a pain aggravator. Chronic pain was not associated with rs10877969 (p = .41).

CONCLUSION

This study shows that rs10877969 is related to indicators of stress and acute pain. Further research is recommended with other measures of stress and acute pain.

A QST-based Pain Phenotype in Adults With Sickle Cell Disease: Sensitivity and Specificity of Quality Descriptors

BACKGROUND

We sought to refine a screening measure for discriminating a sensitized or normal sensation pain phenotype among African American adults with sickle cell disease (SCD).

OBJECTIVE

To develop scoring schemes based on sensory pain quality descriptors; evaluate their performance on classifying patients with SCD who had sensitization or normal sensation, and compare with scores on the Self-report Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) and the Neuropathic Pain Symptom Inventory (NPSI).

METHODS

Participants completed PAINReportIt, quantitative sensory testing (QST), S-LANSS, and NPSI. Conventional binary logistic regression and least absolute shrinkage and selection operator (lasso) regression were used to obtain 2 sets of weights resulting in 2 scores: the PR-Logistic (PAINReportIt score weighted by conventional binary logistic regression coefficients) and PR-Lasso (PAINReportIt score weighted by lasso regression coefficients). Performance of the proposed scores and the existing scores were evaluated.

RESULTS

Lasso regression resulted in a parsimonious model with non-zero weights assigned to 2 neuropathic descriptors, cold and spreading. We found positive correlations between the PR-Lasso and other scores: S-LANSS (r = 0.22, P < 0.01), NPSI (r = 0.22, P < 0.01), and PR-Logistic (r = 0.35, P < 0.01). The NPSI and PR-Lasso performed similarly at different levels of required specificity and outperformed the S-LANSS and PR-Logistic at the various specificity points.

CONCLUSION

The PR-Lasso offers a way to discriminate a SCD pain phenotype.

Association of Cardiomyopathy With MYBPC3 D389V and MYBPC3Δ25bpIntronic Deletion in South Asian Descendants

Importance

The genetic variant MYBPC3Δ25bp occurs in 4% of South Asian descendants, with an estimated 100 million carriers worldwide. MYBPC3 Δ25bp has been linked to cardiomyopathy and heart failure. However, the high prevalence of MYBPC3Δ25bp suggests that other stressors act in concert with MYBPC3Δ25bp.

Objective

To determine whether there are additional genetic factors that contribute to the cardiomyopathic expression of MYBPC3Δ25bp.

Design, Setting, andParticipants

South Asian individuals living in the United States were screened for MYBPC3Δ25bp, and a subgroup was clinically evaluated using electrocardiograms and echocardiograms at Loyola University, Chicago, Illinois, between January 2015 and July 2016.

Main Outcomes and Measures

Next-generation sequencing of 174 cardiovascular disease genes was applied to identify additional modifying gene mutations and correlate genotype-phenotype parameters. Cardiomyocytes derived from human-induced pluripotent stem cells were established and examined to assess the role of MYBPC3Δ25bp.

Results

In this genotype-phenotype study, individuals of South Asian descent living in the United States from both sexes (36.23% female) with a mean population age of 48.92 years (range, 18-84 years) were recruited. Genetic screening of 2401 US South Asian individuals found an MYBPC3Δ25bpcarrier frequency of 6%. A higher frequency of missense TTN variation was found in MYBPC3Δ25bp carriers compared with noncarriers, identifying distinct genetic backgrounds within the MYBPC3Δ25bp carrier group. Strikingly, 9.6% of MYBPC3Δ25bp carriers also had a novel MYBPC3 variant, D389V. Family studies documented D389V was in tandem on the same allele as MYBPC3Δ25bp, and D389V was only seen in the presence of MYBPC3Δ25bp. In contrast to MYBPC3Δ25bp, MYBPC3Δ25bp/D389V was associated with hyperdynamic left ventricular performance (mean [SEM] left ventricular ejection fraction, 66.7 [0.7%]; left ventricular fractional shortening, 36.6 [0.6%]; P < .03) and stem cell-derived cardiomyocytes exhibited cellular hypertrophy with abnormal Ca2+ transients.

Conclusions and Relevance

MYBPC3Δ25bp/D389V is associated with hyperdynamic features, which are an early finding in hypertrophic cardiomyopathy and thought to reflect an unfavorable energetic state. These findings support that a subset of MYBPC3Δ25bp carriers, those with D389V, account for the increased risk attributed to MYBPC3Δ25bp.

Keys to Recruiting and Retaining Seriously Ill African Americans With Sickle Cell Disease in Longitudinal Studies: Respectful Engagement and Persistence

OBJECTIVES

Sickle cell disease (SCD) is a serious illness with disabling acute and chronic pain that needs better therapies, but insufficient patient participation in research is a major impediment to advancing SCD pain management. The purpose of this article is to discuss the challenges of conducting an SCD study and approaches to successfully overcoming those challenges.

DESIGN

In a repeated-measures, longitudinal study designed to characterize SCD pain phenotypes, we recruited 311 adults of African ancestry. Adults with SCD completed 4 study visits 6 months apart, and age- and gender-matched healthy controls completed 1 visit.

RESULTS

We recruited and completed measures on 186 patients with SCD and 125 healthy controls. We retained 151 patients with SCD with data at 4 time points over 18 months and 125 healthy controls (1 time point) but encountered many challenges in recruitment and study visit completion. Enrollment delays often arose from patients' difficulty in taking time from their complicated lives and frequent pain episodes. Once scheduled, participants with SCD cancelled 49% of visits often because of pain; controls canceled 30% of their scheduled visits. To facilitate recruitment and retention, we implemented a number of strategies that were invaluable in our success.

CONCLUSION

Patients' struggles with illness, chronic pain, and their life situations resulted in many challenges to recruitment and completion of study visits. Important to overcoming challenges was gaining the trust of patients with SCD and a participant-centered approach. Early identification of potential problems allowed strategies to be instituted proactively, leading to success.

Thermal and mechanical quantitative sensory testing values among healthy African American adults

PURPOSE

Only a few studies have reported quantitative sensory testing (QST) reference values for healthy African Americans, and those studies are limited in sample size and age of participants. The study purpose was to characterize QST values in healthy, pain-free African American adults and older adults whose prior pain experiences and psychological status were also measured. We examined the QST values for differences by sex, age, and body test site.

PATIENTS AND METHODS

A cross-sectional sample of 124 pain-free African American adults (age 18-69 years, 49% female) completed demographic and self-reported pain, fatigue and psychosocial measures. QST was performed to obtain thermal and mechanical responses and associated pain intensity levels.

RESULTS

We found thermal detection values at the anterior forearm were (29.2 °C±1.6) for cool detection (CD) and (34.5 °C±1.2) for warm detection (WD). At that site the sample had cold pain threshold (CPTh) (26.3 °C±5.0), heat pain threshold (HPTh) (37.8 °C±3.6), and mechanical pain thresholds (MPTH) (16.7±22.2 grams of force, gF). There was a significant between sex difference for WD, with women being more sensitive (q=0.027). Lower body sites were less sensitive than upper body sites across all thermal modalities (q<0.003), but not for the mechanical modality.

CONCLUSION

The QST values from this protocol at the anterior forearm indicate that the healthy African American adults had average thermal pain thresholds close to the temperature of adaptation and average MPTh under 20 gF. Differences in responses to thermal and mechanical stimuli for upper verses lower body were consistent with prior research.

Dendrimer-Based Platform for Effective Capture of Tumor Cells after TGFβ1-Induced Epithelial-Mesenchymal Transition

Detection of circulating tumor cells (CTCs) relying on their expression of epithelial cell markers, such as epithelial cell adhesion molecule (EpCAM), has been commonly used. However, this approach unlikely captures CTCs that have undergone the process of epithelial-mesenchymal transition (EMT). In this study, we have induced EMT of in vitro prostate (PCa) and breast cancer (BCa) cell lines by treatment of transforming growth factor β 1 (TGFβ1), a pleiotropic cytokine with transition-regulating activities. We found that the TGFβ1-treated, post-EMT cells exhibited up to a 45% reduction in binding affinity to antibodies against EpCAM (aEpCAM). To overcome this limitation, we designed our capture platform that integrates a unique combination of biomimetic cell rolling, dendrimer-mediated multivalent binding, and antibody cocktails of aEpCAM/aEGFR/aHER-2. Our capture surfaces resulted in up to 98% capture efficiency of post-EMT cells from mixtures of TGFβ1-treated and untreated cancer cells spiked in culture media and human blood. In a clinical pilot study, our CTC device was also able to capture rare CTCs from PCa patients with significantly enhanced capture sensitivity and purity compared to the control surface with aEpCAM only, demonstrating its potential to provide a reliable detection solution for CTCs regardless of their EMT status.

Neuropathic Pain Screening: Construct Validity in Patients With Sickle Cell Disease

Individuals with pain from sickle cell disease (SCD) are often treated for nociceptive pain, but recent findings indicate they may also have neuropathic pain. PAINReportIt, a computerized version of the McGill Pain Questionnaire, provides a potential subscale that is the summed number of selected neuropathic pain quality words (PR-NNP), but it lacks construct validity. The study purpose was to ascertain PR-NNP construct validity in adults with SCD and chronic pain. In an outpatient setting, 186 participants completed the PAINReportIt, Neuropathic Pain Symptom Inventory (NPSI), and Leeds Assessment for Neuropathic Symptoms and Signs (S-LANSS). PR-NNP was moderately correlated with NPSI (r = .33, p < .001) and S-LANSS (r = .40, p < .001). Regression analysis indicated that PR-NNP and pain intensity, but not a nociceptive pain subscale, were significant predictors of NPSI and S-LANSS. Findings support construct validity of PR-NNP, which may be useful as a screening tool for neuropathic pain in patients with SCD.

Beta2-Adrenergic Receptor Polymorphisms and Haplotypes Associate With Chronic Pain in Sickle Cell Disease

Pain in sickle cell disease (SCD) is severe, variable, and inadequately comprehended. The β2-adrenergic receptor (ADRB2) is critical in mediating neurotransmitter response in the sympathetic nervous system. In this association study, we examined 16 single nucleotide polymorphisms (SNPs) covering 5'-UTR and coding regions of ADRB2 for pain variability in SCD. Subjects recorded their non-crisis, baseline pain experience on a computerized tool from which we obtained chronic pain measurement score- composite pain index (CPI). Regression models yielded significant associations between chronic pain and seven SNPs. Non-synonymous SNP rs1042713 A allele (Arg16) caused a 5.73-fold decrease in CPI (p = 0.002). Allele A of rs12654778 and T of rs17778257 reduced CPI by a fold of 4.52 (p = 0.019), and 4.39 (p = 0.032), respectively. Whereas, in the 5' UTR, allele C of rs1042711, G of rs11168070, C of rs11959427, and C of rs1801704 increased CPI by a fold of 10.86 (p = 0.00049), 5.99 (p = 0.016), 5.69 (p = 0.023), and 5.26 (p = 0.031), respectively. Together, these SNPs accounted for 2-15% of CPI variance after adjusting for covariates. Moreover, these SNPs were in high linkage disequilibrium (LD) showing three LD blocks in our cohort. A 10-marker haplotype increased CPI by 11.5-fold (p = 0.000407). Thus, ADRB2 polymorphisms might contribute to chronic pain severity and heterogeneity in SCD.

Integration of neuropsychology services in a sickle cell clinic and subsequent healthcare use for pain crises

Objective: Growing literature has documented the clinical utility of neuropsychological evaluations for predicting functional outcomes, including reduced healthcare service utilization, in a variety of clinical samples. The present study investigates the relationship between the integration of clinical neuropsychology services into an existing outpatient sickle cell clinic and frequency of emergency department (ED) visits and hospitalizations for pain crises. Method: Participants included 144 adults diagnosed with sickle cell disease (SCD) who either underwent neuropsychological evaluation (NP+), including interview, neuropsychological testing, and feedback, or treatment as usual (NP-). Medical records were reviewed for a two-year period, one year prior to study enrollment (pre-assessment) and one year post-study enrollment (post-assessment), to track the number of ED visits and hospitalizations related to sickle cell pain crises. Results: When examining pain crises ED visits prior to and following neuropsychological evaluation, there was a significant decrease in ED visits for the NP + group, but no change for the NP - group. No significant changes in pain crises hospitalizations were observed for the NP + and NP - groups. For the NP + group, the decreased incidence of pain crises ED visits and hospitalizations was associated with an estimated total cost savings of $994,821. Discussion: Results highlight that integration of neuropsychology services into an existing outpatient sickle cell clinic may reduce healthcare costs, particularly use of pain crises ED services, for adults with SCD.

Oral administration of the LSD1 inhibitor ORY-3001 increases fetal hemoglobin in sickle cell mice and baboons

Increased levels of fetal hemoglobin (HbF) lessen the severity of symptoms and increase the life span of patients with sickle cell disease (SCD). More effective strategies to increase HbF are needed because the current standard of care, hydroxyurea, is not effective in a significant proportion of patients. Treatment of the millions of patients projected worldwide would best be accomplished with an orally administered drug therapy that increased HbF. LSD1 is a component of corepressor complexes that repress γ-globin gene expression and are a therapeutic target for HbF reactivation. We have shown that subcutaneous administration of RN-1, a pharmacological LSD1 inhibitor, increased γ-globin expression in SCD mice and baboons, which are widely acknowledged as the best animal model in which to test the activity of HbF-inducing drugs. The objective of this investigation was to test the effect of oral administration of a new LSD1 inhibitor, ORY-3001. Oral administration of ORY-3001 to SCD mice (n = 3 groups) increased γ-globin expression, Fetal Hemoglobin (HbF)-containing (F) cells, and F reticulocytes (retics). In normal baboons (n = 7 experiments) treated with ORY-3001, increased F retics, γ-globin chain synthesis, and γ-globin mRNA were observed. Experiments in anemic baboons (n = 2) showed that ORY-3001 increased F retics (PA8695, predose = 24%, postdose = 66.8%; PA8698: predose = 13%, postdose = 93.6%), γ-globin chain synthesis (PA8695: predose = 0.07 γ/γ+β, postdose = 0.20 γ/γ+β; PA8698: predose = 0.02 γ/γ+β, postdose = 0.44 γ/γ+β), and γ-globin mRNA (PA8695: predose = 0.06 γ/γ+β, postdose = 0.18 γ/γ+β; PA8698: predose = 0.03 γ/γ+β, postdose = 0.33 γ/γ+β). We conclude that oral administration of ORY-3001 increases F retics, γ-globin chain synthesis, and γ-globin mRNA in baboons and SCD mice, supporting further efforts toward the development of this drug for SCD therapy.

Glucocorticoid receptor single nucleotide polymorphisms are associated with acute crisis pain in sickle cell disease

AIM

Pain in sickle cell disease patients is heterogeneous and genetic polymorphisms may predispose an individual to varied vulnerability to painful events. We studied the association of SNPs in the glucocorticoid receptor gene (NR3C1) with pain in sickle cell disease.

METHOD

Acute pain was scored as the number of utilizations due to crisis pain in a 12-month period. Chronic pain was calculated as the Composite Pain Index score.

RESULTS & CONCLUSION

rs33389 T allele (IRR = 1.53, p = 0.014 additive; IRR = 1.64, p = 0.011 recessive), rs2963155 G allele (IRR = 1.80, p < 0.001 additive; IRR = 2.25, p = 0.021 dominant; IRR = 2.07, p < 0.001 recessive) and rs9324918 C allele (IRR = 1.43, p = 0.021 additive) were associated with higher utilization rates, indicating the potential contribution of NR3C1 polymorphisms to acute pain heterogeneity in sickle cell disease.

Haploidentical Peripheral Blood Stem Cell Transplantation Demonstrates Stable Engraftment in Adults with Sickle Cell Disease

We report on the screening and development of haploidentical hematopoietic stem cell transplantation (HSCT) for adult patients with clinically aggressive sickle cell disease (SCD) at our institution. Of 50 adult SCD patients referred for HSCT between January 2014 and March 2017, 20% were denied by insurance. Of 41 patients initially screened, 10% lacked an available haploidentical donor, 29% had elevated donor-specific antibodies (DSAs), and 34% declined to proceed to HSCT. All 10 patients who were transplanted received peripheral blood stem cells. The initial 2 were conditioned with alemtuzumab/total body irradiation (TBI) 3 Gy followed by post-transplant cyclophosphamide and failed to engraft. The next 8 patients received the regimen developed at Johns Hopkins University with TBI 3 Gy. Granulocyte colony-stimulating factor was administered from day +12 in those with HbS < 30%. All 8 patients engrafted with a median time to neutrophil >.5 × 109/L of 22 days (range, 18 to 23). One patient subsequently lost the graft, and 7 (87.5%) maintained >95% donor cell chimerism at 1-year post-HSCT. Two patients developed acute graft-versus-host disease (GVHD) of at least grade II. One had chronic GVHD and died >1 year after HSCT of unknown causes. With a median follow-up of 16 months (range, 11 to 29), 7 patients (87.5%) are alive. Our findings suggest that limited insurance coverage, high rate of DSAs, and patient declining HSCT may limit the availability of haploidentical HSCT in adult SCD patients. The modified Hopkins regimen used here demonstrates high engraftment and low morbidity rates and should be tested in larger, multicenter, prospective clinical trials.

Genetic variants of GCH1 associate with chronic and acute crisis pain in African Americans with sickle cell disease

The multidimensional nature of pain in sickle cell disease (SCD) has rendered its therapeutic management extremely challenging. In this study, we explored the role of five single nucleotide polymorphisms (SNPs) of candidate gene GCH1 in SCD pain. Composite pain index (CPI) scores and acute care utilization rates were used as phenotype markers. Rs8007267 was associated with chronic pain (additive model: B = -3.76, p = 0.037; dominant model: B = -5.61, p = 0.021) and rs3783641 (additive model: incident rate ratio [IRR] = 1.37, p = 0.024; recessive model: IRR = 1.81, p = 0.018) with utilization rate. These associations persisted when subjects with HbSS and HbSβ° genotype only were analyzed. We also identified two haploblocks (rs10483639[G>C]-rs752688[C>T]-rs4411417[T>C] and rs3783641[T>A]-rs8007267[T>C]) with SNPs in high linkage disequilibrium. Of these, haplotype T-C of haploblock rs3783641-rs8007267 showed significant association with rate of utilization (odds ratio [OR] = 0.31, p = 0.001). Our study indicates potential contribution of GCH1 polymorphisms to the variability of pain in African Americans with SCD.

Risk factors for vitamin D deficiency in sickle cell disease

Vitamin D deficiency (VDD), 25-OHD levels <20 ng/ml, is prevalent among patients with sickle cell disease (SCD) and is linked to acute and chronic pain and bone fracture in this population. There is limited literature regarding VDD-associated risk factors for SCD. We examined potential clinical and genomic parameters associated with VDD in 335 adults with SCD in a cross-sectional study. VDD was present in 65% of adult SCD patients, and 25-OHD levels independently and positively correlated with older age (P < 0·001) and vitamin D supplementation (P < 0·001). 25-OHD levels were higher in SCD patients over 40 years of age compared to the general African-American population. Both lower 25-OHD levels and increased pain frequency were associated with increased expression of SLC6A5 encoding glycine transporter-2 (GlyT2), a protein involved in neuronal pain pathways. Lower 25-OHD levels were also associated with increased expression of CYP3A4, and with decreased expression of GC (also termed DBP) and VDR, three genes involved in vitamin D metabolism. We conclude that vitamin D supplementation should be an almost universal feature of the care of young adults with SCD, and that further research is warranted into genomic factors that regulate vitamin D metabolism in SCD.

Transient receptor potential polymorphism and haplotype associate with crisis pain in sickle cell disease

AIM

Episodes of acute pain crisis contribute to considerable morbidity and mortality in sickle cell disease (SCD). Incomprehensive understanding of the underlying pain heterogeneity results in inadequate pain management. The transient receptor potential (TRP) family of voltage-gated ion channels acts as sensory transducers of diverse noxious stimuli. We performed an association study of polymorphisms in candidate genes TRPV1 and TRPA1 with pain in SCD patients.

METHODS

Utilization rate, in other words, number of emergency department/acute care center admissions over 12 months as a result of pain crisis, served as a marker for acute pain.

RESULTS & CONCLUSION

We identified that rs920829 (incident rate ratio = 1.44, p = 0.027 additive; IRR=1.68, p=0.008 recessive models of negative binomial regression) and the CGAGG haplotype of TRPA1 (odds ratio = 0.218, p = 0.009) were significantly associated with utilization rate, suggesting that TRPA1 gene polymorphisms may influence acute pain crisis in SCD.

The AVPR1A Gene and Its Single Nucleotide Polymorphism rs10877969: A Literature Review of Associations with Health Conditions and Pain

BACKGROUND

Pain is the quintessential symptom for individuals suffering from sickle cell disease (SCD). Although the degree of suffering and the cost of treatment are staggering, SCD continues to be grossly understudied, including a lack of data for pain-related genes and prevalence of polymorphisms in this population. This lack of data adds to the inadequacy of pain therapy in this population. Pain genetics investigators have recently examined allele frequencies of single-nucleotide polymorphisms from candidate genes in people who have SCD. One of the genes identified was the arginine vasopressin receptor 1A gene (AVPR1A) and its associated single-nucleotide polymorphism (SNP) rs10877969. Progress in explaining pain-related polymorphisms associated with SCD can be facilitated by understanding the literature. Aim/Design: The purpose of this literature review was to describe mechanisms of the polymorphic gene AVPR1A and the phenotypic variations associated with its SNPs relative to health conditions and pain.

METHODS

Published studies were included if the research addressed AVPR1A and was a full article in a peer-reviewed journal, in the English language, a human or animal study, and published 2009 to present. Abstracts were included if they were in English and provided information not found in a full article.

RESULTS

The results of this review revealed that AVPR1A is associated with behavioral phenotypes, which include pair bonding, autism spectrum disorder, musical aptitude, infidelity, altruism, monogamy, mating, substance abuse, and alcohol preference. In addition, there were associations with pain, stress pain by sex, and sickle cell pain.

CONCLUSION

Summary of this literature could provide insights into future pain research of this SNP in people with SCD.

Differences in Sensory Pain, Expectation, and Satisfaction Reported by Outpatients with Cancer or Sickle Cell Disease

BACKGROUND

Patients with sickle cell disease (SCD) report pain scores that appear greater than those reported in a meta-analysis for patients with cancer, but statistical comparisons of the pain scores from both populations have not been published.

AIMS

The goal of the study described here was to compare pain outcomes reported by outpatients with cancer or SCD.

DESIGN

Descriptive comparative study.

SETTING

Outpatient oncology or sickle cell clinics.

SUBJECTS

The participants were outpatients (N = 415) from three studies: (1) 106 patients with SCD, 93% African-American (referent group); (2) 140 patients with cancer, 90% Caucasian (race discordant); (3) 169 patients with cancer, 20% Caucasian, 65% African-American (race concordant).

METHODS

Patients completed the PAINReportIt including pain location, quality, pattern, intensity, expectation, satisfaction, and demographic questions. Analyses included the χ² test, analysis of variance, and regression.

RESULTS

Outpatients with SCD reported more pain location sites than the race-discordant (p < .001) and race-concordant (p < .001) cancer groups; higher pain quality than the race-discordant (p < .001) and race-concordant (p < .001) groups; and greater pain pattern scores than the race-discordant (p < .001) and race-concordant (p < .001) groups. The race-concordant group reported higher worst pain intensity than the SCD (p < .001) and race-discordant (p = .002) groups. The three groups did not differ significantly on pain expectation (p = .06). Regarding satisfaction with pain level, there was a significant difference between the race-concordant and SCD (p = .006) groups, but not between the race-discordant and SCD (p = .12) groups or between the race-discordant and race-concordant (p = .49) groups.

CONCLUSIONS

Outpatients with SCD reported three of four sensory pain parameters that were greater than those reported by outpatients with cancer. A better understanding of these differences is pertinent to improving pain outcomes.