Point-of-care screening for sickle cell disease in low-resource settings: A multi-center evaluation of HemoTypeSC, a novel rapid test.

Sickle cell disease (SCD) is a common, life-threatening genetic disorder that is best managed when diagnosed early by newborn screening. However, SCD is most prevalent in low-resource regions of the world where newborn screening is rare and diagnosis at the point-of-care is challenging. In many such regions, the majority of affected children die, undiagnosed, before the age of 5 years. A rapid and affordable point-of-care test for SCD is needed. The diagnostic accuracy of HemoTypeSC, a point-of-care immunoassay, for SCD was evaluated in individuals who had SCD, hemoglobin C disease, the related carrier (trait) states, or a normal hemoglobin phenotype. Children and adults participated in low-, medium- and high-resource environments (Ghana [n = 383], Martinique [n = 46], and USA [n = 158]). Paired blood specimens were obtained for HemoTypeSC and a reference diagnostic assay. HemoTypeSC testing was performed at the site of blood collection, and the reference test was performed in a laboratory at each site. In 587 participants, across all study sites, HemoTypeSC had an overall sensitivity of 99.5% and specificity of 99.9% across all hemoglobin phenotypes. The test had 100% sensitivity and specificity for sickle cell anemia. Sensitivity and specificity for detection of normal and trait states were >99%. HemoTypeSC is an inexpensive (<$2 per test), accurate, and rapid point-of-care test that can be used in resource-limited regions with a high prevalence of SCD to provide timely diagnosis and support newborn screening programs.

Headache and migraine in children with sickle cell disease are associated with lower hemoglobin and higher pain event rates but not silent cerebral infarction.

OBJECTIVE: To identify risk factors for headache and migraine in children with sickle cell disease and test the hypothesis that either or both are independently associated with silent cerebral infarcts. STUDY DESIGN: In this cross-sectional study, we evaluated the health history, laboratory values, and brain magnetic resonance imaging findings of participants with sickle cell disease (hemoglobinSS or hemoglobinSß°-thalassemia) with no history of overt stroke or seizures. Participants characterized headache severity and quality. Migraine was defined by International Headache Society criteria modified for increased sensitivity in children. Neuroradiology and neurology committees adjudicated the presence of silent cerebral infarction by review of magnetic resonance imaging and standardized examination by pediatric neurologists. RESULTS: The cohort included 872 children (51.1% males), ranging in age from 5 to 15 years (mean age, 9.1 years). Of these children, 317 (36.4%) reported recurrent headaches, and 132 (15.1%) reported migraines. In multivariable logistic regression analyses, both were associated with lower steady-state hemoglobin (P = .01 for headaches; P < .01 for migraines) and higher pain rate (P < .01 for headaches; P < .01 for migraines), defined as the number of admissions requiring opioids in the previous 3 years. The presence of silent cerebral infarction was not associated with recurrent headaches or migraines. Only 1.9% (6 of 317) of children with recurrent headaches received medication for headache prophylaxis. CONCLUSION: Recurrent headaches and migraines are common and undertreated in children with sickle cell disease. Low hemoglobin levels and high pain rates are associated with recurrent headaches and migraines; whereas, silent cerebral infarction is not.

Iron-refractory microcytic anemia as the presenting feature of unicentric Castleman disease in children.

Chronic, iron-refractory, microcytic anemia can be a diagnostic and therapeutic challenge. We report the cases of 2 children with occult, unicentric Castleman disease whose primary presenting feature was a chronic, unexplained, iron-refractory, microcytic anemia. Diagnosis was delayed because neither child had palpable lymphadenopathy and the lymphoproliferation was intra-abdominal. Surgical resection cured the anemia and the Castleman disease. A diagnostic clue to Castleman disease is an elevated concentration of interleukin-6 in blood, which causes anemia by inducing the expression of the iron-regulatory hormone hepcidin.

Increase in invasive Streptococcus pneumoniae infections in children with sickle cell disease since pneumococcal conjugate vaccine licensure.

Invasive pneumococcal disease (IPD) in children with sickle cell disease has decreased with prophylactic penicillin, pneumococcal polysaccharide vaccine, and pneumococcal protein-conjugate vaccine usage. We report 10 IPD cases since pneumococcal protein-conjugate vaccine licensure, including a recent surge of non-vaccine serotypes. IPD continues to be a serious risk in sickle cell disease.

Prevalence of intracardiac shunting in children with sickle cell disease and stroke.

OBJECTIVE: To determine the prevalence of potential intracardiac shunts, including patent foramen ovale (PFO), in children with sickle cell disease (SCD) and stroke. STUDY DESIGN: We performed a transthoracic echocardiogram (TTE) on 40 children with SCD (39 with hemoglobin SS and 1 with sickle-beta0 thalassemia) and earlier stroke (overt stroke in 30, silent infarction in 10). We compared 3 TTE techniques: conventional 2-dimensional imaging, color Doppler ultrasound, and intravenous agitated saline contrast injection for the detection of intracardiac shunts. We also evaluated the clinical, laboratory, and radiographic findings of the children with and without shunts. RESULTS: We identified PFO or other potential intracardiac shunts in 10 of 40 children with SCD and earlier stroke (25%; 95% CI, 11.6-38.4). With contrasted TTE, we failed to detect potential shunts in 2 children. In a comparison group of 60 children with stroke but without SCD, retrospective review of clinical echocardiograms identified PFO in 7 of 60 (11.7%; 95% CI, 3.6-19.8). Clinical features significantly associated with the presence of intracardiac shunts were stroke in the setting of vaso-occlusive crisis (P = .026) and headache at stroke onset (P = .014). CONCLUSION: One-quarter of children with SCD and stroke have potential intracardiac shunts. A combination of echocardiographic techniques is required for optimal shunt detection. Intracardiac shunting could be a risk factor for stroke in children with SCD because they are predisposed to thrombosis and elevations of right heart pressure, which could promote paradoxical embolization across an intracardiac shunt.