Enhancing Pain Assessment in Pediatric Sickle Cell Disease by Applying Quality Improvement Science.

OBJECTIVE: Standardized pain assessment and interventions are recommended for youth hospitalized for pain. This quality improvement (QI) project integrated into a pediatric psychology service aimed to increase the standardized assessment of pain-related functional ability for youth with sickle cell disease (SCD) hospitalized for pain. METHODS: Children and adolescents (n=102) with SCD referred for psychology consultation for poor coping in response to pain during hospitalization completed a validated self-report of functional ability in addition to pain intensity during inpatient psychology visits. At the time of the quality initiative, routine and standardized assessment of pain-related functional ability was not integrated into standard clinical care. Plan, Do, Study, Act (PDSA) cycles determined the feasibility and addressed common barriers of routine assessment and documentation of pain-related functional ability among youth with SCD during inpatient psychology visits with the primary goal to increase assessment of functional ability to at least 85% among patients with SCD referred for pediatric psychology consultation to address pain management within 1 year. RESULTS: Through iterative PDSA cycles, routine assessment of pain-related functional ability during psychology visits increased to an average of 93% over the course of 12 months. Routine, standardized assessment of functional ability was considered feasible within a pediatric psychology service. CONCLUSIONS/LESSONS LEARNED: This project supported the feasibility of integrating standardized assessment of functional ability to enhance pain assessment for youth hospitalized for SCD pain as part of routine clinical care in a multidisciplinary setting regardless of psychology referral.

A Phase 3 Trial of l-Glutamine in Sickle Cell Disease.

BACKGROUND: Oxidative stress contributes to the complex pathophysiology of sickle cell disease. Oral therapy with pharmaceutical-grade l-glutamine (USAN, glutamine) has been shown to increase the proportion of the reduced form of nicotinamide adenine dinucleotides in sickle cell erythrocytes, which probably reduces oxidative stress and could result in fewer episodes of sickle cell-related pain. METHODS: In a multicenter, randomized, placebo-controlled, double-blind, phase 3 trial, we tested the efficacy of pharmaceutical-grade l-glutamine (0.3 g per kilogram of body weight per dose) administered twice daily by mouth, as compared with placebo, in reducing the incidence of pain crises among patients with sickle cell anemia or sickle ß0-thalassemia and a history of two or more pain crises during the previous year. Patients who were receiving hydroxyurea at a dose that had been stable for at least 3 months before screening continued that therapy through the 48-week treatment period. RESULTS: A total of 230 patients (age range, 5 to 58 years; 53.9% female) were randomly assigned, in a 2:1 ratio, to receive l-glutamine (152 patients) or placebo (78 patients). The patients in the l-glutamine group had significantly fewer pain crises than those in the placebo group (P=0.005), with a median of 3.0 in the l-glutamine group and 4.0 in the placebo group. Fewer hospitalizations occurred in the l-glutamine group than in the placebo group (P=0.005), with a median of 2.0 in the l-glutamine group and 3.0 in the placebo group. Two thirds of the patients in both trial groups received concomitant hydroxyurea. Low-grade nausea, noncardiac chest pain, fatigue, and musculoskeletal pain occurred more frequently in the l-glutamine group than in the placebo group. CONCLUSIONS: Among children and adults with sickle cell anemia, the median number of pain crises over 48 weeks was lower among those who received oral therapy with l-glutamine, administered alone or with hydroxyurea, than among those who received placebo, with or without hydroxyurea. (Funded by Emmaus Medical; ClinicalTrials.gov number, NCT01179217 .).

Widespread Pain Among Youth With Sickle Cell Disease Hospitalized With Vasoocclusive Pain: A Different Clinical Phenotype?

OBJECTIVES: The purpose of this study was to describe the clinical phenotype of widespread pain (WSP) among youth with sickle cell disease (SCD) hospitalized with vasoocclusive pain. MATERIALS AND METHODS: One hundred fifty-six youth with SCD, between 7 and 21 years of age hospitalized at 4 children's hospitals for a vasoocclusive episode were evaluated. Data were collected during 1 day of the hospitalization. RESULTS: Using the 2010 American College of Rheumatology guidelines, 21.8% of patients were identified as having WSP (pain in 7 or more unique body locations). Patients classified as having WSP had higher pain intensity (6.5 vs. 5.6; t=2.19, P=0.03) higher pain burden (13.0 vs. 9.8; t=3.09, P=0.002), higher acute functional disability (22.1 vs. 16.5; t=2.43, P=0.016), higher chronic functional disability (30.4 vs. 22.2; t=2.31, P=0.02), lower positive affect (22.9 vs. 27.6; t=2.23, P=0.027), and lower quality of life (56.2 vs. 62.9; t=1.99, P=0.049) than those youth with SCD without WSP. DISCUSSION: Assessment of WSP may identify a unique clinical phenotype of youth with SCD with differing treatment needs.

Tissue Doppler Imaging-derived Diastolic Function Assessment in Children With Sickle Cell Disease and Its Relation With Ferritin.

Diastolic dysfunction has been shown to occur earlier than systolic dysfunction in iron overload states in adult patients with sickle cell disease (SCD). Tissue Doppler imaging (TDI)-derived E/E' has emerged as a noninvasive marker of diastolic function. We sought to determine diastolic function in children with SCD and study its relation with iron overload. A retrospective review of medical records of 225 pediatric patients with SCD who received an echocardiogram between January 2008 and December 2012 was performed. Echocardiographic measures including M-mode, spectral Doppler, and TDI-derived E/E' were compared with previously published data in healthy children. The left ventricular end-diastolic and end-systolic dimensions were significantly higher in SCD (P<0.0001) and the shortening fraction was similar (P=0.66). E/E' ratio was significantly higher in SCD at the mitral annulus, septum, and tricuspid annulus. In 54% of subjects, the septal E/E' was >8, indicating elevated left ventricular filling pressure. However, there was no significant correlation between ferritin level and E/E' ratios. Pediatric patients with SCD have a high prevalence of elevated estimated left ventricular filling pressure, but this does not correlate with ferritin levels.

Impact of red blood cell alloimmunization on sickle cell disease mortality: a case series.

BACKGROUND: Although red blood cell (RBC) transfusion represents an integral component of sickle cell disease (SCD) care, transfusion support for some patients can result in alloimmunization to RBC antigens. Alloimmunized patients with SCD appear to experience worse survival compared to nonalloimmunized patients. While this difference in mortality may in part be due to underlying immunologic differences related to disease severity, it may also reflect direct clinical consequences of RBC alloimmunization. Alloimmunized patients have an increased risk of serious hemolytic transfusion reactions (HTRs) and may not receive adequate RBC transfusion support due to lack of compatible RBC units. CASE REPORT: This study reports on five RBC alloimmunized patients with SCD who died, to illustrate the concept that RBC alloimmunization itself contributes to premature death. RESULTS: The clinical course for each of the reported patients provides insight into the direct and indirect consequences of RBC alloimmunization, where patients experienced delayed HTRs or did not receive needed RBC transfusions. CONCLUSION: Future work examining the clinical impact of RBC alloimmunization should not only consider HTRs but should also address the potential consequences associated with difficulties in obtaining compatible blood.

Elevated tricuspid regurgitant velocity as a marker for pulmonary hypertension in children with sickle cell disease: less prevalent and predictive than previously thought?

Although elevated tricuspid regurgitant velocity (TRV), an echocardiographic marker for pulmonary hypertension, has previously been tied to mortality in adult patients with sickle cell disease, recent data demonstrated that it correlates poorly with catheterization findings. We describe the largest echocardiographic evaluation of pediatric patients with sickle cell disease to date, specifically the results of a protocol whereby a TRV≥250 cm/s prompted further evaluation. We investigated if elevated TRV would independently identify patients at risk for increased morbidity. A clinical echocardiographic database containing 630 patients with sickle cell disease was retrospectively reviewed; 120 patients (19%) met inclusion criteria and were compared 1:1 to randomly selected age-matched controls from the same database. By multivariate analysis, the elevated TRV cohort did not differ from controls in likelihood of acute chest episodes, hospitalization, or stroke. The study cohort's mean TRV in fact decreased to 242±33 cm/s at follow-up without a discernible and comprehensive intervention to explain the improvement. Three patients had catheterization-proven pulmonary hypertension. In conclusion, elevated TRV in children with sickle cell disease is less prevalent than previously thought and is not independently associated with increased short-term morbidity.

Development and validation of the Youth Acute Pain Functional Ability Questionnaire (YAPFAQ).

UNLABELLED: Physical function and functional recovery are important aspects of the acute pain experience in children and adolescents in hospitalized settings. Measures of function related to pediatric acute pain do not exist currently, limiting understanding of recovery in youth undergoing acute and procedural pain. To address this gap, we developed and assessed the clinical utility and preliminary validity of the Youth Acute Pain Functional Ability Questionnaire (YAPFAQ). We evaluated psychometric properties of this measure in 159 patients with sickle cell disease, ages 7 to 21 years, who were hospitalized for vaso-occlusive episodes at 4 urban children's hospitals. The YAPFAQ demonstrated strong internal reliability and test-retest reliability. An exploratory factor analysis was conducted to examine the preliminary factor structure and to help reduce the number of items for the final scale. Evidence for moderate construct validity was demonstrated among validated measures of pain burden, motor function, functional ability, and quality of life. The YAPFAQ is a new measure of youth functional ability in the acute pain setting. Further evaluation of this measure in additional pediatric populations is needed to understand applicability across a spectrum of youth experiencing acute pain related to illness, trauma, and medical/surgical procedures. PERSPECTIVE: Measures of function in response to acute pain are needed in order to more comprehensively evaluate acute pain interventions in pediatrics; however, no specific measures are available. Our preliminary psychometric evaluation of an acute pain functional ability measure for youth indicates that it may be a promising tool for further refinement in additional pediatric acute pain populations.

Management of refractory pain in hospitalized adolescents with sickle cell disease: changing from intravenous opioids to continuous infusion epidural analgesia.

BACKGROUND: Prolonged hospitalizations for sickle cell disease painful episodes are not uncommon, as analgesic options are often suboptimal. OBSERVATIONS: Seven patients (15.4 ± 3.7 y, 6 females) were treated with epidural analgesia for refractory pain. The median duration of epidural catheter placement was 4 days (interquartile range, 3 to 6 d). Mean pain scores changed from 6.8 ± 2.7 to 4.8 ± 2.2, whereas mean daily parenteral opioid requirements changed from 79.7 ± 100.4 to 13.0 ± 13.1 mg of morphine equivalents. CONCLUSION: Continuous epidural analgesia is an alternative to continuing intravenous opioids in sickle cell disease patients with refractory pain, and may reduce opioid-related side effects and facilitate transition to oral analgesics.

Validation of the sickle cell disease pain burden interview-youth.

UNLABELLED: The purpose of this study was to develop and validate a brief, clinically relevant, multidimensional interview to assess pain burden among children and adolescents with sickle cell disease (SCD). The Sickle Cell Disease Pain Burden Interview-Youth (SCPBI-Y) was developed using a panel of experts, patients, and caregivers. Validation was undertaken with children and youth with SCD, ages 7 to 21 years (N = 129), recruited from 4 urban children's hospitals. Participants were recruited from inpatient (n = 62) and outpatient (n = 67) settings. The SCPBI-Y demonstrated strong internal consistency reliability, cross-informant concordance (child-caregiver), and test-retest reliability (outpatient setting). Moderate construct validity was found with validated measures of functional ability, pain, and quality of life. The SCPBI-Y demonstrated construct validity using a contrasted group approach between youth in inpatient versus outpatient settings and by severity of SCD symptoms, suggesting that youth in inpatient settings and with higher disease severity exhibited greater pain burden. Discriminant validity was found between SCPBI-Y and mood. Our preliminary findings suggest that the SCPBI-Y is a valid and reliable multidimensional interview that can be used in different clinical settings to evaluate pain burden among children and adolescents with SCD. PERSPECTIVE: Multifaceted pain assessments are salient in providing optimal care to children and adolescents with SCD; however, current evaluations are lengthy and cumbersome to administer clinically. The current study introduces and validates a brief, clinically useful multidimensional interview to evaluate pain burden specific to youth with SCD.

SickleREMOTE: A Two-Way Text Messaging System for Pediatric Sickle Cell Disease Patients.

Sickle cell disease, the most common hemoglobinopathy in the world, affects patient lives from early childhood. Effective care of sickle cell disease requires frequent medical monitoring, such as tracking the frequency, severity, and duration of painful events. Conventional monitoring includes paper- or web-based reporting diaries. These systems require that patients carry forms, which are easily lost, or laptop computers, which are impractical to scale to large populations. Both are prone to sporadic use by older adolescents due to lack of reminders. In this paper, we design and prototype a Sickle cell disease REporting and MOnitoring TElemedicine system (SickleREMOTE), aiming to resolve limitations of conventional monitoring diaries. This monitoring system is configured as automated short message service text (SMS-text) messages that arrive at a mobile phone anywhere on a cellular network. The messages may be reminders to encourage treatment adherence or questionnaires to collect self-assessed clinical data relating to treatment adjustments. Patients respond to the messages using pre-determined templates and a cloud database parses and stores messages automatically. Providers use a web-based interface to view, analyze, and download collected data. SickleREMOTE is developed by Georgia Institute of Technology in conjunction with Children's Healthcare of Atlanta (CHOA). System effectiveness will be evaluated using a trial of 30 adolescents with sickle cell disease and measured by response rate, time to response, error rate, and correspondence with data collected by telephone calls.

TNP-470 promotes initial vascular sprouting in xenograft tumors.

TNP-470 (AGM-1470), an analogue of fumagillin, was one of the first molecules proposed to have antiangiogenic properties. This concept was based on its ability to inhibit both endothelial proliferation in vitro and tumor growth in vivo in a number of xenograft models. Yet, subsequent investigations indicated that the biochemical activities associated with TNP-470 are not selective for endothelial cells. Moreover, recent evidence suggests that this agent inhibits tumor growth in vivo, but without a corresponding decrease in angiogenesis. Therefore, we performed a detailed comparison of TNP-470 to a validated antiangiogenic agent, a VEGF inhibitor termed VEGF-Trap, using a xenograft model of Wilms tumor. Treatment with TNP-470 for 5 weeks significantly suppressed xenograft growth (83%). Surprisingly, this inhibition was not associated with a decrease in angiogenesis, but instead with an increase in tiny neovessels. To determine whether this was a direct effect of TNP-470 on tumor vessels, we examined its effect in a short-term assay using large tumors with established vasculature. In contrast to treatment with VEGF-Trap, which led to rapid vessel regression and tumor hypoxia, tumors exposed to TNP-470 for 1 day displayed increased capillary sprouting, with significantly increased microvessel density, vessel length, and branch points. TNP-470 did not induce tumor hypoxia as demonstrated by minimal pimonidazole staining and VEGF expression. TNP-470 did, however, cause a marked increase in apoptosis of tumor cells. Our results indicate that the antitumor effects of TNP-470 cannot be attributed to prevention of neoangiogenesis, but instead to its direct action on tumor cells.

Vascular remodeling marks tumors that recur during chronic suppression of angiogenesis.

The potential for avoiding acquired resistance to therapy has been proposed as one compelling theoretical advantage of antiangiogenic therapy based on the normal genetic status of the target vasculature. However, previous work has demonstrated that tumors may resume growth after initial inhibition if antiangiogenic blockade is continued for an extended period. The mechanisms of this recurrent growth are unclear. In these studies, we characterized molecular changes in vasculature during apparent resumption of xenograft growth after initial inhibition by vascular endothelial growth factor blockade, "metronome" topotecan chemotherapy, and combined agents in a xenograft murine model of human Wilms' tumor. Tumors that grew during antiangiogenic blockade developed as viable clusters surrounding strikingly remodeled vessels. These vessels displayed significant increases in diameter and active proliferation of vascular mural cells and expressed platelet-derived growth factor-B, a factor that functions to enhance vascular integrity via stromal cell recruitment. In addition, remodeled vessels were marked by expression of ephrinB2, required for proper assembly of stromal cells into vasculature. Thus, enhanced vascular stability appears to characterize tumor vessel response to chronic antiangiogenesis, features that potentially support increased perfusion and recurrent tumor growth.

Thalidomide is anti-angiogenic in a xenograft model of neuroblastoma.

Thalidomide has previously been shown to have anti-angiogenic properties. More recently, clinical efficacy of this agent has been demonstrated in multiple myeloma and prostate cancer. Neuroblastoma is the most frequent solid tumor of the abdomen of childhood, yet children with this disease frequently have metastases at presentation. Such patients have a very poor prognosis with current therapies. Thus, new approaches are needed. We have previously shown that VEGF antagonists can inhibit neoangiogenesis and tumor growth in experimental neuroblastoma. In this study, we investigated the anti-angiogenic and anti-tumor properties of thalidomide in a xenograft model of human neuroblastoma. Tumors were induced in athymic mice using the human neuroblastoma cell line NGP. Intraperitoneal thalidomide (100 mg/kg/dose) or vehicle was administered beginning one week after implantation, and animals euthanized at six weeks. Thalidomide treatment did not significantly alter tumor growth as compared with controls. However, thalidomide suppressed angiogenesis, as demonstrated both by fluorescein angiography and immunohistochemical staining, and induced apoptosis of endothelial cells in neuroblastoma xenografts. Quantification of microvessel density demonstrated a significant reduction of vasculature in treated tumors (p<0.004). Thalidomide induced co-option of host vasculature, an effect noted previously after VEGF blockade. This study demonstrates that thalidomide has anti-angiogenic properties in experimental neuroblastoma.

Human epidermal growth factor receptor signaling contributes to tumor growth via angiogenesis in her2/neu-expressing experimental Wilms' tumor.

BACKGROUND: The human epidermal growth factor family (HER) members play a significant role in the mesenchymal-to-epithelial transition during renal tubulogenesis. HER misexpression has been linked also to loss of growth control, invasiveness, and promotion of angiogenesis in breast cancers and other human malignant tumors METHODS: The authors screened Wilms' tumor samples and derived cell lines for expression of her2/neu, which was detected in both unfavorable and favorable histology tissues. Xenografts were implanted in mice using her2/neu(+) and her2/neu(-) cell lines and the effect of specific blockade tested using monoclonal anti-her2/neu antibody. RESULTS: Blocking antibody suppressed tumor growth in her2/neu(+) but not her2/neu(-) experimental Wilms' tumor. In addition, antibody exposure resulted in suppression of tumor angiogenesis but no decrease in tumor cell proliferation in her2/neu(+) xenografts. CONCLUSIONS: Her2/neu contributes to the growth of some Wilms' tumors, and an important mechanism of its action is promotion of angiogenesis.

Blockade of her2/neu decreases VEGF expression but does not alter HIF-1 distribution in experimental Wilms tumor.

Her2/neu regulates angiogenesis in human breast cancer, in part by stabilizing hypoxia-inducible factor 1alpha (HIF-1alpha), causing accumulation of the HIF-1 heterodimer and thus increasing expression of the proangiogenic cytokine VEGF. Her2/neu has recently been shown to be overexpressed in a subset of Wilms tumors. Using her2/neu (+) and her2/neu (-) Wilms tumor cell lines, we tested the effect of blocking anti-her2/neu antibody in vitro and in vivo. Blocking antibody did not alter VEGF expression in vitro, but decreased expression of VEGF in her2/neu (+) Wilms tumor xenografts. Tumor suppression was less marked than in parallel experiments using agents directly blocking VEGF. HIF-1alpha immunostaining was not altered in her2/neu (+) xenografts exposed to blocking antibody. These results suggest that her2/neu contributes to Wilms tumor angiogenesis in vivo by regulating VEGF, but other processes may act to rescue HIF-1alpha and thus to support tumor growth in this system.

Regression of established tumors and metastases by potent vascular endothelial growth factor blockade.

Vascular endothelial growth factor (VEGF) is a critical promoter of blood vessel growth during embryonic development and tumorigenesis. To date, studies of VEGF antagonists have primarily focused on halting progression in models of minimal residual cancer. Consistent with this focus, recent clinical trials suggest that blockade of VEGF may impede cancer progression, presumably by preventing neoangiogenesis. However, VEGF is also a key mediator of endothelial-vascular mural cell interactions, a role that may contribute to the integrity of mature vessels in advanced tumors. Here, we report that high-affinity blockade of VEGF, using the recently described VEGF-Trap, abolishes mature, preexisting vasculature in established xenografts. Eradication of vasculature is followed by marked tumor regression, including regression of lung micrometastases. Thus, the contribution of relatively low levels of VEGF to vessel integrity may be critical to maintenance of even very small tumor masses. Potent blockade of VEGF may provide a new therapeutic option for patients with bulky, metastatic cancers.

Anti-VEGF antibody in experimental hepatoblastoma: suppression of tumor growth and altered angiogenesis.

BACKGROUND: Hepatoblastoma is the most common primary hepatic malignancy of childhood, frequently presenting as advanced disease. Vascular endothelial growth factor (VEGF) is an endothelial mitogen and survival factor critical to growth and angiogenesis in many human cancers. Inhibition of VEGF effectively suppresses tumorigenesis in multiple experimental models. The authors hypothesized that anti-VEGF antibody would alter vascular architecture and impede tumor growth in experimental hepatoblastoma. METHODS: The Institutional Animal Care and Use Committee of Columbia University approved all protocols. Xenografts were established in athymic mice by intrarenal injection of cultured human hepatoblastoma cells. Anti-VEGF antibody (100 microg/dose) or vehicle was administered intraperitoneally 2 times per week for 5 weeks. At week 6, 10 control/treated mice were killed and remaining animals maintained without treatment until week 8. Tumor weights were compared by Kruskal-Wallis analysis, and vascular alterations ascertained by fluorescein angiography and specific immunostaining. RESULTS: Anti-VEGF antibody significantly inhibited tumor growth at 6 weeks (1.85 g +/- 0.60 control, 0.05 +/- 0.03 antibody, P <.0003). In comparison with controls, treated xenografts showed decreased vascularity and dilated surviving vessels with prominent vascular smooth muscle elements. CONCLUSIONS: Specific anti-VEGF therapy inhibits neoangiogenesis and significantly suppresses tumor growth in experimental hepatoblastoma. Surviving vasculature displays dilation and increased vascular smooth muscle. Anti-VEGF agents may represent new therapeutic alternatives for children with advanced disease.

Potent VEGF blockade causes regression of coopted vessels in a model of neuroblastoma.

Vascular endothelial growth factor (VEGF) plays a key role in human tumor angiogenesis. We compared the effects of inhibitors of VEGF with different specificities in a xenograft model of neuroblastoma. Cultured human neuroblastoma NGP-GFP cells were implanted intrarenally in nude mice. Three anti-VEGF agents were tested: an anti-human VEGF(165) RNA-based fluoropyrimidine aptamer; a monoclonal anti-human VEGF antibody; and VEGF-Trap, a composite decoy receptor based on VEGFR-1 and VEGFR-2 fused to an Fc segment of IgG1. A wide range of efficacy was observed, with high-dose VEGF-Trap causing the greatest inhibition of tumor growth (81% compared with controls). We examined tumor angiogenesis and found that early in tumor formation, cooption of host vasculature occurs. We postulate that this coopted vasculature serves as a source of blood supply during the initial phase of tumor growth. Subsequently, control tumors undergo vigorous growth and remodeling of vascular networks, which results in disappearance of the coopted vessels. However, if VEGF function is blocked, cooption of host vessels may persist. Persistent cooption, therefore, may represent a novel mechanism by which neuroblastoma can partly evade antiangiogenic therapy and may explain why experimental neuroblastoma is less susceptible to VEGF blockade than a parallel model of Wilms tumor. However, more effective VEGF blockade, as achieved by high doses of VEGF-Trap, can lead to regression of coopted vascular structures. These results demonstrate that cooption of host vasculature is an early event in tumor formation, and that persistence of this effect is related to the degree of blockade of VEGF activity.