The Risk of Kidney Injury in Patients With Sickle Cell Disease Treated With Ketorolac for Acute Pain

Ketorolac, a nonsteroidal anti-inflammatory drug, is used in combination with opioids to manage vaso-occlusive episodes (VOEs). The relationship between ketorolac use and kidney injury in pediatric patients with sickle cell disease (SCD) remains incompletely understood. We hypothesize that ketorolac is associated with acute kidney injury (AKI) in patients with SCD presenting with pain. All nonsurgical hospitalizations for VOEs treated with ketorolac between January 2014 and December 2022 were included. We used optimal matching methodology to identify control admissions (2:1 ratio) and used nonparametric tests to compare ketorolac administration between cases and controls. A total of 1319 encounters/253 patients were included in this study. AKI was noted in 1.1% of encounters and 5.5% of patients. Cases had significantly higher initial BUN than controls (9.0 vs. 6.0 mg/dL, P=0.012). In cases versus controls, there was significantly lower serum sodium (136.0 vs. 138.0 mmol/L, P=0.021). There was no association between ketorolac dose and development of AKI among children with SCD. Higher BUN and lower sodium in cases suggest that patients with AKI were more volume depleted on admission than controls. This highlights the need for strict assessment of fluid status upon admission for VOE.

Increasing COVID-19 Vaccination Rates for Children With Sickle Cell Disease

BACKGROUND

The COVID-19 vaccine is important for children with sickle cell disease (SCD). This quality improvement project's objective was to increase the proportion of children with SCD receiving ≥2 COVID-19 vaccine doses to ≥70% by June 2022.

METHODS

We used the Model for Improvement framework. We assessed COVID-19 vaccination rates biweekly. Three plan-do-study-act cycles focusing on patient education, provider awareness, and access were performed. Process measures included the outcome of outreach calls and educational video views. Missed clinic appointments was our balancing measure. Line graphs and statistical process control charts were used to track changes. Interrupted time series was used to model implementation rates while accounting for preexisting trends.

RESULTS

A total of 243 patients were included. During the preintervention (September 2021-January 2022) and intervention periods (February 2022-June 2022), overall vaccination rates increased from 33% to 41% and 41% to 64%, respectively. Mean vaccination rate in eligible children in each 2-week period increased from 2.1% to 7.2%. The achieved vaccination rate was 11% greater than predicted for patients with SCD. For the general population the achieved vaccination rate was 23% lower than predicted. The proportion of missed visits did not change (9.0% vs. 9.6%). During outreach calls, 10 patients (13.5%) booked a vaccine. Forty percent of patients watched the promotional video.

CONCLUSIONS

A significant number of patients with SCD are not vaccinated against COVID-19. Targeting misinformation and improving vaccine access aided in increasing vaccination. Additional interventions are needed as a large number of patients remain unvaccinated.

F-erythrocytes promote Plasmodium falciparum proliferation in sickle cell disease

BACKGROUND

Sickle cell disease (SCD) remains prevalent because heterozygous carriers (HbAS) are partially resistant to Plasmodium falciparum malaria. Sickle hemoglobin (HbS) polymerization in low and intermediate oxygen (O2 ) conditions is the main driver of HbAS-driven resistance to P. falciparum malaria. However, epidemiological studies have reported mixed malaria morbidity and mortality outcomes in individuals with sickle cell disease (SCD). While maximum-tolerated dose hydroxyurea has been shown to lower malaria incidence, fetal hemoglobin (HbF), an inhibitor of HbS polymerization that is variably packaged in F-erythrocytes, might provide hemoglobin that is accessible to the parasite for feeding.

METHODS

To explore that risk, we examined the effect of variable mean corpuscular fetal hemoglobin (MCHF) on P. falciparum proliferation, invasion, and development in HbSS RBCs.

RESULTS

We found that greater MCHF in HbSS red blood cells (RBCs) is associated with increased P. falciparum proliferation in O2 environments comparable with the microcirculation. Moreover, both parasite invasion and intracellular growth, the major components of proliferation, occur predominantly in F-erythrocytes and are augmented with increasing MCHF.

CONCLUSIONS

HbF modifies P. falciparum infection in HbSS RBCs, further highlighting the complexity of the molecular interactions between these two diseases. Other inhibitors of HbS polymerization that do not increase HbF or F-erythrocytes should be independently assessed for their effects on P. falciparum malaria proliferation in HbSS RBCs.

Genetic reversal of the globin switch concurrently modulates both fetal and sickle hemoglobin and reduces red cell sickling

We previously reported initial clinical results of post-transcriptional gene silencing of BCL11A expression (NCT03282656) reversing the fetal to adult hemoglobin switch. A goal of this approach is to increase fetal hemoglobin (HbF) expression while coordinately reducing sickle hemoglobin (HbS) expression. The resulting combinatorial effect should prove effective in inhibiting HbS polymerization at lower physiologic oxygen values thereby mitigating disease complications. Here we report results of exploratory single-cell analysis of patients in which BCL11A is targeted molecularly and compare results with cells of patients treated with hydroxyurea (HU), the current standard of care. We use single-cell assays to assess HbF, HbS, oxygen saturation, and hemoglobin polymer content in RBCs for nine gene therapy trial subjects (BCLshmiR, median HbF% = 27.9) and compare them to 10 HU-treated subjects demonstrating high and comparable levels of HbF (HU High Responders, median HbF% = 27.0). All BCL11A patients achieved the primary endpoint for NCT03282656, which was defined by an absolute neutrophil count greater than or equal to 0.5 × 109 cells/L for three consecutive days, achieved within 7 weeks following infusion. Flow cytometric assessment of single-RBC HbF and HbS shows fewer RBCs with high HbS% that would be most susceptible to sickling in BCLshmiR vs. HU High Responders: median 42% of RBCs with HbS%>70% in BCLshmiR vs. 61% in HU High Responders (p = 0.004). BCLshmiR subjects also demonstrate more RBCs resistant to HbS polymerization at lower physiologic oxygen tension: median 32% vs. 25% in HU High Responders (p = 0.006). Gene therapy-induced BCL11A down-regulation reverses the fetal-to-adult hemoglobin switch and induces RBCs with higher HbF%, lower HbS%, and greater resistance to deoxygenation-induced polymerization in clinical trial subjects compared with a cohort of highly responsive hydroxyurea-treated subjects.

Ketamine use for management of vaso-occlusive pain in pediatric sickle cell disease

BACKGROUND

Typical sickle cell disease (SCD) vaso-occlusive pain episode (VOE) management includes opioids, which are often inadequate and can be associated with significant side effects. Ketamine, a dissociative anesthetic, is a potentially effective adjunct to VOE management.

OBJECTIVES

This study aimed to characterize ketamine use for VOE management in pediatric SCD.

METHOD

This retrospective case series summarizes a single-center experience regarding the use of ketamine for inpatient management of pediatric VOE in 156 admissions from 2014 to 2020.

RESULTS

Continuous low-dose ketamine infusion was most commonly prescribed to adolescents and young adults as an adjunct to opioids (median starting dose 2.0 μg/kg/min; median maximum dose 3.0 μg/kg/min). Ketamine was started a median of 13.7 hours after admission. Median ketamine infusion duration was 3 days. In most encounters, ketamine infusion was discontinued prior to opioid patient-controlled analgesia (PCA) discontinuation. The majority of encounters (79.3%) had a reduction in either PCA dose, continuous opioid infusion, or both while receiving ketamine. Low-dose ketamine infusion was associated with side effects noted in 21.8% (n = 34) of encounters. The most common side effects included dizziness (5.6%), hallucinations (5.1%), dissociation (2.6%), and sedation (1.9%). There were no reports of ketamine withdrawal. Most patients who received ketamine went on to receive it again during a subsequent admission.

CONCLUSION

Further study is needed to determine the optimal timing of ketamine initiation and dosing. The variability of ketamine administration highlights the need for standardized protocols for ketamine use in VOE management.

Patient Controlled Analgesia for Vaso-Occlusive Episodes in Children: A Retrospective Study

OBJECTIVE

To describe Patient-Controlled Analgesia (PCA) administration in pediatric patients admitted with sickle cell vaso-occlusive episode (VOE).

METHODS

This single-center retrospective study included all inpatient hematology admissions for VOE between 2014 and 2020. PCA-ratio was calculated as the ratio of bolus over continuous IV opioids dose, and time to PCA adjustment as time between first PCA order and a subsequent order that increased dosing or changed opioid medication.

RESULTS

A total of 866 encounters (172 unique patients) with PCA for VOE were included. The mean age was 15.4 years old (SD = 5.0). On average, after admission (hospital arrival), the first opioid dose was given at 1 hour, PCA started at 3.5 hours, and mean length of stay was 4.3 days (SD = 2.5). The mean initial PCA-ratio was 1.7 (SD = 0.6). There were no significant associations between age, gender, initial pain score, or admission hemoglobin and PCA-ratio (linear regression model P = 0.443). In 24.7% of encounters, the PCA was adjusted within 6 hours. After adjusting by age and gender, lower admission pain scores (OR = 1.15, P = 0.004), lower PCA-ratio (OR = 2.1, P = 0.003), longer time to PCA start (OR = 1.2, P = 0.001), and no adjuvant ketamine (OR = 2.4, P < 0.001) were associated with PCA unadjusted within 6 hours.

CONCLUSION

At our institution, patients with VOE received opioids and PCA within the first hours of admission. PCAs were started at a ratio of 1.5-1.8, considered normal continuous. While no specific PCA-ratio was clearly superior for pain control, lower ratios (high continuous infusion) were associated with not requiring PCA adjustments at 6 hours. Prospective studies are needed.

Enablers and barriers to newborn screening for sickle cell disease in Africa: results from a qualitative study involving programmes in six countries

OBJECTIVES

Given the fundamental role of newborn bloodspot screening (NBS) to enable prompt diagnosis and optimal clinical management of individuals with sickle cell disease (SCD), we sought to systematically assess enablers and barriers to implementation of NBS programmes for SCD in Africa using established qualitative research methods.

SETTING

Childbirth centres and NBS laboratories from six countries in East, West and Southern Africa.

PARTICIPANTS

Eight programme leaders involved with establishing and operating NBS programmes for SCD in Angola, Democratic Republic of Congo, Ghana, Liberia, Nigeria and Tanzania.

PRIMARY AND SECONDARY OUTCOME MEASURES

Data obtained through a structured, phased interview approach were analysed using a combination of inductive and deductive codes and used to determine primary themes related to the implementation and sustainability of SCD NBS programmes.

RESULTS

Four primary themes emerged from the analysis relating to governance (eg, pragmatic considerations when deploying overcommitted clinical staff to perform NBS), technical (eg, design and execution of operational processes), cultural (eg, variability of knowledge and perceptions of community-based staff) and financial (eg, issues that can arise when external funding may effectively preclude government inputs) aspects. Key learnings included perceived factors that contribute to long-term NBS programme sustainability.

CONCLUSIONS

The establishment of enduring NBS programmes is a proven approach to improving the health of populations with SCD. Organising such programmes in Africa is feasible, but initial implementation does not assure sustainability. Our analysis suggests that future programmes should prioritise government partner participation and funding from the earliest stages of programme development.

A systematic review of ketamine for the management of vaso-occlusive pain in sickle cell disease

Vaso-occlusive episodes (VOEs) are a common complication of sickle cell disease (SCD) and a significant cause of morbidity. Managing VOE pain can be difficult and complex. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has been used to manage VOE pain. This systematic literature review synthesizes research published from 2010 to 2020 on the use of ketamine infusion to decrease VOE pain. The review demonstrates that ketamine, a safe and effective treatment for VOE pain, could be considered more widely. However, the significant variability among published clinical studies with regard to dosing, timing of initiation, duration of infusion, and timing of discontinuation highlights the need for standardized ketamine infusion protocols for the management of VOE pain. We conclude with a brief discussion of key components of a potential standardized protocol supported by the literature reviewed as well as areas for future investigation.

Association of Blood Type With Postsurgical Mucosal Bleeding in Pediatric Patients Undergoing Tonsillectomy With or Without Adenoidectomy

IMPORTANCE

Blood type (BT) O has been identified as a risk factor for bleeding complications, while non-O BTs may increase risk for thromboembolic events. Limited data are available in children undergoing tonsillectomy with or without adenoidectomy.

OBJECTIVE

To determine whether BT O is associated with hemorrhage after tonsillectomy with or without adenoidectomy.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of patients younger than 22 years who underwent tonsillectomy with or without adenoidectomy at a single institution between January 1, 2008, and August 7, 2017. Statistical analysis was performed from November 2017 to January 2019.

MAIN OUTCOMES AND MEASURES

Prevalence of hemorrhage following surgery was defined as any bleeding requiring cauterization up to 1 month after the procedure. Data on sex, age, von Willebrand disease (VWD) status, BT, white blood cell counts, and platelet counts closest to date of surgery were collected from an electronic medical record system, and the association of these factors with hemorrhage following surgery was investigated.

RESULTS

A total of 14 951 pediatric patients (median [range] age, 5.6 [0.8-21.9] years; 6956 [46.5%] female) underwent tonsillectomy with or without adenoidectomy. Prevalence of hemorrhage following the procedure was 3.9% (578 patients) for the full cohort and 2.8% (362 of 13 065) for patients with no BT identified or preprocedure VWD panel results at baseline. Children who had a BT identified and/or a VWD panel before surgery had higher bleeding rates (BT only, 14.9% [172 of 1156]; preprocedure VWD panel only, 4.6% [28 of 607]; and BT and preprocedure VWD panel, 13.0% [16 of 123]), all of which were significantly different from the baseline bleeding rate (P < .001). While the bleeding rates in children with BT O were not statistically different from those with non-O BT (14.8% and 14.6%, respectively; P > .99), mean von Willebrand factor values were statistically different (mean [SD] von Willebrand factor antigen level in O group, 86.9 [42.4] IU/dL in the O group vs 118.0 [53.8] IU/dL in the non-O group; P = .002; and mean [SD] von Willebrand factor ristocetin-cofactor in the O group, 72.2 [44.3] IU/dL vs 112.6 [68.0] IU/dL in the non-O group; P = .001). In addition, children older than 12 years had increased bleeding rates in the full cohort (8.3% vs 3.2%), in the testing-naive cohort (6.5% vs 2.3%), and in those with a preprocedure VWD panel only (13.5% vs 3.1%) compared with children aged 12 years or younger.

CONCLUSIONS AND RELEVANCE

Type O blood was not a risk factor associated with hemorrhage after tonsillectomy with or without adenoidectomy despite lower baseline von Willebrand factor antigen and von Willebrand factor ristocetin-cofactor values in children with BT O vs those with non-O BT in our study cohort. No association was found between VWD status and bleeding, and there was no difference in VWD panel values in those who experienced hemorrhage vs those who did not within BT groups. Further studies elucidating the utility of von Willebrand factor values for children undergoing tonsillectomy with or without adenoidectomy are needed.

Fetal hemoglobin does not inhibit Plasmodium falciparum growth

P falciparum growth is not inhibited in either cord or heterozygote hereditary persistence of fetal hemoglobin erythrocytes. P falciparum growth in fetal hemoglobin erythrocytes is oxygen independent.

Erythrocyte ion content and dehydration modulate maximal Gardos channel activity in KCNN4 V282M/+ hereditary xerocytosis red cells

Hereditary xerocytosis (HX) is caused by missense mutations in either the mechanosensitive cation channel PIEZO1 or the Ca²⁺-activated K⁺ channel KCNN4. All HX-associated KCNN4 mutants studied to date have revealed increased current magnitude and red cell dehydration. Baseline KCNN4 activity was increased in HX red cells heterozygous for KCNN4 mutant V282M. However, HX red cells maximally stimulated by Ca²⁺ ionophore A23187 or by PMCA Ca²⁺-ATPase inhibitor orthovanadate displayed paradoxically reduced KCNN4 activity. This reduced Ca²⁺-stimulated mutant KCNN4 activity in HX red cells was associated with unchanged sensitivity to KCNN4 inhibitor senicapoc and KCNN4 activator Ca²⁺, with slightly elevated Ca²⁺ uptake and reduced PMCA activity, and with decreased KCNN4 activation by calpain inhibitor PD150606. The altered intracellular monovalent cation content of HX red cells prompted experimental nystatin manipulation of red cell Na and K contents. Nystatin-mediated reduction of intracellular K⁺ with corresponding increase in intracellular Na⁺ in wild-type cells to mimic conditions of HX greatly suppressed vanadate-stimulated and A23187-stimulated KCNN4 activity in those wild-type cells. However, conferral of wild-type cation contents on HX red cells failed to restore wild-type-stimulated KCNN4 activity to those HX cells. The phenotype of reduced, maximally stimulated KCNN4 activity was shared by HX erythrocytes expressing heterozygous PIEZO1 mutants R2488Q and V598M, but not by HX erythrocytes expressing heterozygous KCNN4 mutant R352H or PIEZO1 mutant R2456H. Our data suggest that chronic KCNN4-driven red cell dehydration and intracellular cation imbalance can lead to reduced KCNN4 activity in HX and wild-type red cells.

Pediatric sialoblastoma: Evaluation and management

OBJECTIVES

Sialoblastoma is a rare congenital salivary gland tumor of epithelial origin. The objectives of this study are to review the literature regarding clinical presentation of sialoblastoma, evaluate the effectiveness of various treatment methods, and present guidelines for evaluation and management in the pediatric population.

DATA SOURCES

Case presentation and literature review.

REVIEW METHODS

A comprehensive search was conducted to identify cases of pediatric sialoblastoma in the English-language literature. The presentation, evaluation, and management of reported cases were analyzed. We also report an invasive and recurrent case in a pediatric patient to highlight the aggressive nature of these lesions.

RESULTS

Sixty-two cases of pediatric sialoblastoma were reviewed. The age at initial presentation ranged from before birth to 15 years. The parotid gland was the most common location (n = 47). Surgical excision was the primary treatment in all patients. Nine patients developed metastatic disease of the lung, lymph nodes, or bone. Almost a third of patients had recurrence and over two thirds of patients were tumor-free for at least 1 year following their last treatment intervention.

CONCLUSION

Prompt and complete surgical excision should be recommended to prevent local and systemic recurrence of pediatric sialoblastoma. Chemotherapy has also shown promise in several cases, and clinical genomics may shed light on more therapy options. Patients should be closely followed for at least 12 months following diagnosis, or longer depending on the histopathological staging of the tumor.

An Increased Risk of Second Malignant Neoplasms After Rhabdomyosarcoma: Population-Based Evidence for a Cancer Predisposition Syndrome?

BACKGROUND

Rhabdomyosarcoma survivors have an increased risk of developing second malignant neoplasms (SMN); this risk is traditionally attributed to the effects of multidisciplinary management required for cure. However, the impact of constitutional predisposition has not been properly analyzed.

METHODS

We analyzed the risk of SMN among 1,151 children diagnosed with rhabdomyosarcoma and reported to the Surveillance, Epidemiology, and End Results registries (SEER-9) from 1973 to 2010. Standardized incidence ratios (SIR) and corresponding 95% confidence intervals (CI) were calculated using SEERStat 8.1.2.

RESULTS

Children with pleomorphic and embryonal rhabdomyosarcoma had an increased risk of developing a SMN (SIR = 15.77, 95%CI 1.91-56.96 and SIR = 5.6, 95%CI 3.32-8.85, respectively). The risk was age-dependent; the highest was among children <2 years (SIR = 13.38, 95%CI 4.34-31.22) and the lowest was in children >10 years (SIR = 3.35, 95%CI 1.53-6.35). The risk for the youngest patients was higher for those with embryonal rhabdomyosarcoma (SIR = 14.72, 95%CI 4.01-37.70) compared to other histiotypes. Additionally, the risk of SMN was independent of the use of radiation to the primary (SIR = 6.50, 95%CI 3.97-10.03 and SIR = 4.57, 95%CI 2.09-8.68, for children receiving and not receiving radiation, respectively). The pattern of SMN observed was consistent with the Li-Fraumeni spectrum.

CONCLUSIONS

Children with rhabdomyosarcoma are at high risk of developing SMN. This risk is higher for a subgroup of young children with pleomorphic and embryonal histologies, and is independent of the use of radiation. This suggests that a subgroup of children with pleomorphic and embryonal rhabdomyosarcoma may have a constitutional cancer predisposition.

Anaplastic rhabdomyosarcoma in TP53 germline mutation carriers

BACKGROUND

Rhabdomyosarcoma (RMS) represents a diverse category of myogenic malignancies with marked differences in molecular alterations and histology. This study examines the question if RMS predisposition due to germline TP53 mutations correlates with certain RMS histologies.

METHODS

The histology of RMS tumors diagnosed in 8 consecutive children with TP53 germline mutations was reviewed retrospectively. In addition, germline TP53 mutation analysis was performed in 7 children with anaplastic RMS (anRMS) and previously unknown TP53 status.

RESULTS

RMS tumors diagnosed in 11 TP53 germline mutation carriers all exhibited nonalveolar, anaplastic histology as evidenced by the presence of enlarged hyperchromatic nuclei with or without atypical mitotic figures. Anaplastic RMS was the first malignant diagnosis for all TP53 germline mutation carriers in this cohort, and median age at diagnosis was 40 months (mean, 40 months ± 15 months; range, 19-67 months). The overall frequency of TP53 germline mutations was 73% (11 of 15 children) in pediatric patients with anRMS. The frequency of TP53 germline mutations in children with anRMS was 100% (5 of 5 children) for those with a family cancer history consistent with Li-Fraumeni syndrome (LFS), and 80% (4 of 5 children) for those without an LFS cancer phenotype.

CONCLUSIONS

Individuals harboring germline TP53 mutations are predisposed to develop anRMS at a young age. If future studies in larger anRMS cohorts confirm the findings of this study, the current Chompret criteria for LFS should be extended to include children with anRMS irrespective of family history.