A Heterozygous RAB27A Mutation Associated with Delayed Cytolytic Granule Polarization and Hemophagocytic Lymphohistiocytosis.

Frequently fatal, primary hemophagocytic lymphohistiocytosis (HLH) occurs in infancy resulting from homozygous mutations in NK and CD8 T cell cytolytic pathway genes. Secondary HLH presents after infancy and may be associated with heterozygous mutations in HLH genes. We report two unrelated teenagers with HLH and an identical heterozygous RAB27A mutation (c.259G→C). We explore the contribution of this Rab27A missense (p.A87P) mutation on NK cell cytolytic function by cloning it into a lentiviral expression vector prior to introduction into the human NK-92 cell line. NK cell degranulation (CD107a expression), target cell conjugation, and K562 target cell lysis was compared between mutant- and wild-type-transduced NK-92 cells. Polarization of granzyme B to the immunologic synapse and interaction of mutant Rab27A (p.A87P) with Munc13-4 were explored by confocal microscopy and proximity ligation assay, respectively. Overexpression of the RAB27A mutation had no effect on cell conjugate formation between the NK and target cells but decreased NK cell cytolytic activity and degranulation. Moreover, the mutant Rab27A protein decreased binding to Munc13-4 and delayed granzyme B polarization toward the immunologic synapse. This heterozygous RAB27A mutation blurs the genetic distinction between primary and secondary HLH by contributing to HLH via a partial dominant-negative effect.

Patient-centered approach to designing sickle cell transition education.

INTRODUCTION: It is vital to engage patients with sickle cell disease (SCD) in the transition process from pediatric to adult care. To better understand the patient perspective during the time of transition, we conducted this research with the goal of incorporating patient comprehension and desires for transition education. MATERIALS AND METHODS: We surveyed 37 adolescent patients with SCD about their understanding of SCD and transition education preferences. In addition, patient responses were analyzed to understand differences among urban and rural patients. RESULTS: The mean age of surveyed participants was 14.9 years (SD=2.1). Forty-three percent of participants responded that the topic of transition had been introduced to them, and only 21% responded that they received education about transition. Despite the poor awareness about transition, almost all participants were interested in learning more about the transition process through a technology-based transition education platform where individual health topics could be explored. DISCUSSION: Despite a didactic teaching approach to transition education, we identified that sickle cell participants had poor recognition of receiving transition education and poor understanding of their basic medical history. However, patients can identify specific health topics that should be addressed during an individualized transition education program.

Rates of malignancy associated with juvenile idiopathic arthritis and its treatment.

OBJECTIVE: To determine the relative rates of incident malignancy among children with juvenile idiopathic arthritis (JIA) with respect to treatment as compared to children without JIA. METHODS: Using national Medicaid data from 2000 through 2005, we identified cohorts of children with JIA and without JIA according to the diagnosis codes used by their physicians and the medication prescriptions that were dispensed. Study followup began after a 6-month lag period to exclude prevalent and misdiagnosed malignancies. Treatment with methotrexate (MTX) and tumor necrosis factor (TNF) inhibitors was categorized as ever exposed or never exposed. Malignancy outcomes were identified using an adapted version of a previously validated algorithm. Incident malignancies were categorized as possible, probable, or highly probable based on a comprehensive review of all claims. Malignancy rates were standardized to the age, sex, and race distribution of the overall JIA cohort. Standardized incidence ratios (SIRs) were calculated using children with attention deficit hyperactivity disorder (n = 321,821) (one of two comparator groups included) as the referent group. RESULTS: The JIA cohort included 7,812 children with a total followup time of 12,614 person-years; 1,484 of these children contributed 2,922 person-years of TNF inhibitor exposure. For all children with JIA versus children without JIA, the SIR was 4.4 (95% confidence interval [95% CI] 1.8-9.0) for probable and highly probable malignancies. For those taking MTX without TNF inhibitor use, the SIR was 3.9 (95% CI 0.4-14). Following any use of TNF inhibitors, no probable or highly probable malignancies were identified (SIR 0 [95% CI 0-9.7]). CONCLUSION: Children with JIA appeared to have an increased rate of incident malignancy compared to children without JIA. The treatment for JIA, including TNF inhibitors, did not appear to be significantly associated with the development of malignancy.

Single institution series of nodular fasciitis in children.

Nodular fasciitis often resembles malignant sarcomas from a clinical and pathologic perspective. We describe the case of an infant that presented with a supraclavicular nodular fasciitis that recurred after an initial gross total resection. A review of pathology records at the Children's Hospital of Alabama led to the identification of 18 nodular fasciitis cases between 1997 and 2009, all of which underwent surgical excisions. Patient characteristics were similar to previous studies that detected a broad range of ages at diagnosis, a male predominance, and a predilection for the head and neck. Only one tumor recurred after the initial surgical intervention. All patients ultimately recovered with minimal morbidity.

Hydroxyurea decreases hospitalizations in pediatric patients with Hb SC and Hb SB+ thalassemia.

PURPOSE: Patients with hemoglobin SC (Hb SC) and hemoglobin SB+ (Hb SB+) thalassemia suffer from frequent hospitalizations yet strong evidence of a clinical benefit of hydroxyurea (HU) in this population is lacking. Patients with recurrent hospitalizations for pain crisis are offered HU at our institution based on small cohort data and anecdotal benefit. This study identifies outcomes from a large cohort of patients with Hb SC and SB+ thalassemia who were treated with HU for 2 years. MATERIALS AND METHODS: A retrospective review was conducted of 32 patients with Hb SC and SB+ thalassemia who were treated with HU. We reviewed the number, and reasons for hospitalization in the 2 years prior to, and 2 years post-HU treatment as well as laboratory changes from baseline, over 1 year. RESULTS: Patients with Hb SC and SB+ thalassemia started on HU for frequent pain, had a significant reduction in hospitalizations over 2 years as compared to the 2 years prior to HU initiation (mean total hospitalizations/year: pre-HU: 1.6 vs post-HU 0.4 hospitalizations, P<0.001; mean pain hospitalizations/year: pre-HU 1.5 vs post-HU 0.3 hospitalizations, P<0.001). Patients demonstrated hematologic changes including an increase in percent fetal hemoglobin (%HbF) pre-post HU (4.5% to 7.7%, P=0.002), mean corpuscular volume (74 to 86 fL, P<0,0001), and decrease in absolute neutrophil count (5.0 to 3.2×10(9)/L, P=0.007). Patients with higher doses of HU demonstrated the greatest reduction in hospitalizations but this was unrelated to absolute neutrophil count. CONCLUSION: This cohort of patients with Hb SC and SB+ thalassemia provides additional support for using HU in patients with recurrent hospitalizations for pain. A large randomized multicenter trial of HU to reduce pain admissions should be conducted to confirm these data and provide much needed evidence based recommendations for this population.

Encephaloduroarteriosynangiosis and encephalomyoarteriosynangiosis for treatment of moyamoya syndrome in pediatric patients with sickle cell disease.

OBJECT Pediatric patients with sickle cell disease (SCD) and moyamoya syndrome (MMS) are at significant risk for cerebrovascular accidents despite chronic transfusion therapy. Encephaloduroarteriosynangiosis (EDAS) and encephalomyoarteriosynangiosis (EMAS) are additional therapeutic options for these patients. To date, the incidence of complications after and efficacy of EDAS and EMAS in stroke prevention in this population have been described in several institutional case series reports, but no randomized prospective trials have been reported. METHODS The authors retrospectively reviewed the cases of all pediatric patients at the University of Alabama at Birmingham with a history of homozygous hemoglobin S (HbS) and sickle cell/ß-thalassemia (SB0 thalassemia) and on chronic transfusion therapy, including 14 patients with MMS who underwent EDAS or EMAS. RESULTS Sixty-two patients with SCD and on chronic transfusion therapy were identified. After exclusion of patients on chronic transfusion therapy for indications other than stroke prevention, 48 patients (77.4%) remained. Of those patients, 14 (29.1%) underwent EDAS or EMAS. Nine (18.8%) and 25 (52.1%) patients were on chronic transfusion therapy for primary or secondary stroke prevention, respectively, but did not undergo EDAS or EMAS. The 14 patients with SCD and radiological evidence of MMS and on chronic transfusion therapy for primary or secondary stroke prevention underwent 21 EDAS or EMAS procedures for progressive vascular disease (92.9% of patients), stroke (71.4%), and/or seizure (7.1%). The mean (± SD) time from initiation of chronic transfusion therapy to EDAS or EMAS was 76.8 ± 58.8 months. Complications included 1 perioperative stroke, 1 symptomatic subdural hygroma, 1 postoperative seizure, and 1 case of intraoperative cerebral edema that required subsequent cranioplasty. Before EDAS or EMAS, the stroke rate was calculated to be 1 stroke per 7.8 patient-years. One additional stroke occurred during the follow-up period (mean follow-up time 33.7 ± 19.6 months), resulting in a post-EDAS/EMAS stroke rate of 1 stroke per 39.3 patient-years, a 5-fold reduction compared with that in the pre-EDAS/EMAS period. The patients' mean pre-EDAS/EMAS HbS level of 29.5% ± 6.4% was comparable to the mean post-EDAS/EMAS HbS level of 25.5% ± 6.1% (p = 0.104). CONCLUSIONS The results of this retrospective case series in a large cohort of pediatric patients with SCD and MMS suggest that EDAS/EMAS provides a stroke-prevention benefit with an acceptably low morbidity rate. Given the combined experience with EDAS and EMAS for this indication at this and other institutions, a prospective clinical trial to assess their efficacy compared with that of chronic transfusion therapy alone is warranted.

Barriers in transition from pediatrics to adult medicine in sickle cell anemia.

Transition of care from pediatric to adult providers is an essential step in the care of young adults with sickle cell anemia. Transition programs should be developed by individual institutions to systematically enhance the transition process for their patients. Prior to transfer, patients must be educated about their disease and personal medical history and develop skill sets required to navigate the adult health care setting. The objective of this literature review is to identify key concepts associated with transition of care for patients with sickle cell anemia. First, transition programs should be developed so that education about transition can begin at an early age. The readiness of patients and families should be assessed and education tailored to meet individual patient needs. Finally, the emotions and fears about transition should be recognized and addressed prior to transition.